Search

Olive oil production, with a market value of 13.4 billion euros, generates annually 10 million tons of olive mill solid waste (OMSW), yet sustainable technologies for the valorisation of this material are still missing at industrial scale. This study presents a techno-economic assessment focused on the recovery of biogas via anaerobic digestion and co-digestion with pig manure. Lab-scale results showed how the anaerobic digestion of OMSW as a sole substrate was not stable, with poor methane yield and accumulation of volatile fatty acids. Conversely, co-digestion with pig manure increased the methane yield by 3.5-fold, which was attributed to an increase in the buffer capacity, the dilution of phenolic compounds and an improved nutrient balance. Based on these results, the techno-economic assessment showed the feasibility of scaling-up the process, with a net present value of 312 k€ and a payback period of 8 years. Therefore, this consolidated technology should play a role in the ecological and energy transition of the sector., This research was funded by PRIMA Foundation (4BIOLIVE project PCI2021-121979). S. Correa is grateful to the Generalitat de Catalunya for her predoctoral scholarship (2021 FISDUR 00057). F. Passos is grateful to the Spanish Ministry of Universities for her Maria Zambrano Fellowship (UP2021-034)., Postprint (published version)

Spain produces 45% of the world's olive oil, generating more than 3,000,000 tons of alperujo annually, its main by-product. The properties of alperujo, such as its acidity, high concentrations of polyphenols, and lignocellulosic material, hinder its efficient valorization, leading to the exploration of alternatives in the agricultural sector. In this study, carried out by the Grup d'Enginyeria i Microbiologia del Medi Ambient (GEMMA), the valorization of fresh and pretreated alperujo was evaluated in anaerobic digestion, both in mono-digestion and co-digestion with pig slurry at a 2:1 ratio. The pretreatment was performed with ionic liquid [Et3NH][HSO4] at 60% at 120 ºC for 4 hours, to remove lignin and increase organic matter. The research was carried out over a total of 84 days, with an HRT of 21 days, allowing for the evaluation of biogas production, methane concentration, reactor stability, and substrate characterization. The pretreated alperujo increased the phenol concentration in the substrate from 6.52 ± 1.00 g/L to 9.22 ± 0.24 g/L, but this did not affect the digestion process. Additionally, values of 1.10 g SV/g DQOs were observed, double those obtained with untreated alperujo, which had 0.54 g SV/g DQOs, indicating better bioavailability. The mono-digestion of alperujo, both fresh and pretreated, is not viable due to the acidity generated. On the other hand, co-digestion with pig slurry proves to be effective and stable. The reactor fed with pretreated alperujo and pig slurry achieved the highest biogas production, with an average of 170.65 ± 27.82 mL CH4/g VS and a methane concentration of 72.39%. This value is 22.84% higher compared to co-digestion with untreated alperujo and pig slurry. The study indicates that pretreatment with ionic liquid, in combination with co-digestion with pig slurry, allows for greater organic matter degradation, improving biogas production. Furthermore, a new line of research is opened regarding the valorization of the generat, Espanya produeix el 45% de l'oli d'oliva mundial, generant més de 3.000.000 de tones anuals de pinyolada, el seu principal subproducte. Les propietats de la pinyolada, com la seva acidesa, les altes concentracions de polifenols i la matèria lignocel·lulòsica, dificulten la seva valorització eficient, cosa que ha portat a buscar alternatives en el sector agrari. En aquest estudi, dut a terme pel Grup d'Enginyeria i Microbiologia del Medi Ambient (GEMMA), es va avaluar la revalorització de la pinyolada fresca i pretractada en digestió anaeròbica tant en monodigestió com en codigestió amb purins de porc en una proporció de 2:1. El pretractament es va fer amb líquid iònic [Et3NH][HSO4] al 60% a 120 ºC durant 4 hores, per eliminar la lignina i augmentar la matèria orgànica. La investigació es va desenvolupar durant un total de 84 dies, amb un TRH de 21 dies, la qual cosa va permetre avaluar la producció de biogàs, la concentració de metà, l'estabilitat dels reactors i la caracterització dels substrats. La pinyolada pretractada va augmentar la concentració de fenols del substrat de 6,52 ± 1,00 g/L a 9,22 ± 0,24 g/L, però no va afectar durant la digestió. A més, es van mostrar valors de 1,10 g SV/g DQOs, sent el doble dels obtinguts amb la pinyolada sense tractar, amb 0,54 g SV/g DQOs, indicant una millor biodisponibilitat. La mono-digestió de pinyolada, tant fresca com pretractada, no és viable a causa de l'acidesa generada. Per altra banda, la co-digestió amb purins es mostra efectiva i estable. El reactor alimentat amb pinyolada pretractada i purins va aconseguir la major producció de biogàs, amb una mitjana de 170,65 ± 27,82 mL CH4/g SV i una concentració de metà del 72,39%. Aquest valor és un 22,84% superior en comparació amb la co-digestió de pinyolada sense tractar amb purins. L'estudi indica que el pretractament amb líquid iònic, en combinació amb la co-digestió amb purins, permet una major degradació de la matèria orgànica, millorant la producció de biogàs. A més, España produce el 45% del aceite de oliva mundial, generando más de 3.000.000 de toneladas de alperujo anuales, su principal subproducto. Las propiedades del alperujo, como su acidez, las altas concentraciones de polifenoles y materia lignocelulósica, dificultan su valorización eficiente, lo que ha llevado a buscar alternativas en el sector agrario. En este estudio, llevado a cabo por el Grup d'Enginyeria i Microbiologia del Medi Ambient (GEMMA), se evaluó la revalorización del alperujo fresco y pretratado en digestión anaerobia tanto en mono-digestión como en co-digestión con purines de cerdo en una proporción de 2:1. El pretratamiento fue con líquido iónico [Et3NH][HSO4] al 60% a 120 ºC durante 4 horas, para eliminar la lignina y aumentar la materia orgánica. La investigación se desarrolló durante un total de 84 días, con un TRH de 21 días, lo que permitió evaluar la producción de biogás, la concentración de metano, la estabilidad de los reactores y la caracterización de los sustratos. El alperujo pretratado aumentó la concentración de fenoles del sustrato de 6,52 ± 1,00 g/L a 9,22 ± 0,24 g/L , pero no afectó durante la digestión. Además, se mostró valores de 1,10 g SV/g DQOs, siendo el doble de los obtenidos con el alperujo sin tratar con 0,54 g SV/g DQOs, indicando una mejor biodisponibilidad. La mono-digestión de alperujo, tanto fresco como pretratado, no es viable debido a la acidez generada. Por otro lado, la co-digestión con purines ser efectiva y estable. El reactor alimentado con alperujo pretratado y purines alcanzó la mayor producción de biogás, con un promedio de 170,65 ± 27,82 mL CH4/g SV y una concentración de metano del 72,39%. Este valor es un 22,84% mayor en comparación con la co-digestión de alperujo sin tratar con purines. El estudio indica que el pretratamiento con líquido iónico en combinación con la co-digestión de purines, permite una mayor degradación de la materia orgánica, mejorando la producción de biogás. Además, se abre una nueva línea, Objectius de Desenvolupament Sostenible::13 - Acció per al Clima, Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura

Biogas production through anaerobic digestion is an important part towards the achievement of a bio-based and circular economy in Sweden. In fact, Swedish government proposed a strategy suggesting that biogas production should be increased from 2 TWh today to 7 TWh by 2030. Sweden has a large potential for biogas production from agricultural residues, not the least the Region Västra Götaland (RVG) where the stakeholders from the present study are located. The study explores the possibilities to use farm manure in co-digestion with deep bedding to produce biogas. The possibilities include two main alternatives for biogas production; mainly combined heat and power (CHP) to produce heat and electricity and biogas upgrading to produce bio-methane. The study took two existing organic farms in the municipality of Götene as a case study as well as an under-construction biogas plant by the company Gasum. The results of the present study also confirm that biogas could be a better option both economically and environmentally than fossil fuels. Additional results show that diesel consumption and energy prices are seen as hotspots that greatly influence both technical performance and economic profitability of biogas production. Another parameter is the geographical location of the studied system which could delimit or enhance the biogas production prospects depending on the proximity to gas grid or biogas unit. The aim of the study is to assess which of the studied alternatives is most profitable and has less environmental impacts; sending liquid manure to a biogas plant and receiving liquid fertilizer in exchange (centralized scenario) or invest in a biogas plant at the farm (on-farm scenario). A life cycle assessment (LCA) was conducted to compare environmental impacts of producing the equivalent of 1 MWh of biogas through on-farm plant and a biogas unit operated by the Finnish company Gasum. While a life cycle costing (LCC) was carried out considering a 10 year period with a

Teniendo en cuenta los altos índices de contaminación de la atmósfera por la explotación de combustibles fósiles en el planeta tierra, la generación de nuevos combustibles alternativos, asequibles y económicos que permitan minimizar esta problemática, es una de las iniciativas que se vienen estudiando ampliamente a nivel mundial. La producción de biogás a partir de materia orgánica representa una de las iniciativas más prometedoras en este campo. Por tal razón, esta publicación presenta un estudio de la influencia de los parámetros fisicoquímicos y operacionales considerados en los modelos de digestión anaerobia, que estudian el rendimiento y calidad del biogás obtenido por esta vía. Los parámetros de operación analizados de la literatura científica como la temperatura, el pH, el tiempo de retención hidráulico, la relación carbono/nitrógeno, entre otros, se pueden utilizar para realizar comparaciones entre diferentes técnicas, lo que permite variar materias primas, establecer condiciones de operación y escalar procesos. Los resultados obtenidos indican que existen diferentes tipos de sustratos, los cuales están asociados a porcentajes de rendimientos considerables, como es el caso del estiércol de cerdo y el vacuno, se establecieron las relaciones carbono/nitrógeno según la materia prima y las reacciones más importantes de la digestión anaerobia. Se confrontaron los datos de la revisión con los obtenidos en el laboratorio de transformación de materiales orgánicos de la Universidad del Atlántico, obteniéndose así una gran similitud en la mayoría de los datos reportados, Considering the high rates of atmospheric pollution caused by the exploitation of fossil fuels on planet Earth, the generation of new, affordable, and economical alternative fuels to minimize this problemis a widely studied initiative. Biogas production from organic matter represents one of the most promising initiatives in this field. For this reason, this publication presents a study of the influence of the physicochemical and operational parameters considered in the anaerobic digestionmodels, which study the yield and quality of the biogas obtained by route. The operating parameters analyzed from the scientific literaturesuch as temperature, pH, hydraulic retention time, carbon/nitrogen ratio, among others,can be used to performcomparisons between different techniques, which allowsvaryingraw materials, establishing operating conditions, and scaling processes. The results indicate that there are different types of substrates, which are associated with considerable yield percentages; as is the case of pig and cattle manure, carbon/nitrogen ratios were established according to the raw material and the most important reactions of anaerobic digestion. The data of the review were compared with those obtained in the laboratory of transformation of organic materials of the Universidad del Atlántico, thus obtaining a great similarity in most of the reported data.

Biogas production through anaerobic digestion is an important part towards the achievement of a bio-based and circular economy in Sweden. In fact, Swedish government proposed a strategy suggesting that biogas production should be increased from 2 TWh today to 7 TWh by 2030. Sweden has a large potential for biogas production from agricultural residues, not the least the Region Västra Götaland (RVG) where the stakeholders from the present study are located. The study explores the possibilities to use farm manure in co-digestion with deep bedding to produce biogas. The possibilities include two main alternatives for biogas production; mainly combined heat and power (CHP) to produce heat and electricity and biogas upgrading to produce bio-methane. The study took two existing organic farms in the municipality of Götene as a case study as well as an under-construction biogas plant by the company Gasum. The results of the present study also confirm that biogas could be a better option both economically and environmentally than fossil fuels. Additional results show that diesel consumption and energy prices are seen as hotspots that greatly influence both technical performance and economic profitability of biogas production. Another parameter is the geographical location of the studied system which could delimit or enhance the biogas production prospects depending on the proximity to gas grid or biogas unit. The aim of the study is to assess which of the studied alternatives is most profitable and has less environmental impacts; sending liquid manure to a biogas plant and receiving liquid fertilizer in exchange (centralized scenario) or invest in a biogas plant at the farm (on-farm scenario). A life cycle assessment (LCA) was conducted to compare environmental impacts of producing the equivalent of 1 MWh of biogas through on-farm plant and a biogas unit operated by the Finnish company Gasum. While a life cycle costing (LCC) was carried out considering a 10 year period with a

Anaerobic co-digestion of sludge increases biogas production and maintains anaerobic digestion stability. However, it is unclear whether the addition of co-substrates may increase the concentration of trace organic contaminants (TrOCs) and metals, limiting potential resource recovery opportunities when applied to agricultural land. This study explored the occurrence of 20 TrOCs and 18 metals in wastewater sludge anaerobically co-digested with beverage rejects (cola, beer and juice) and food wastes. TrOCs results showed that cola reject caused an accumulation of caffeine in final digestate. Bisphenol A also significantly increased in food waste co-digestion when compared with the mono-digestion (control). No significant difference in TrOCs was observed in the juice reject co-digestion. Analysis of the metal composition revealed a significant increase in Cr and Al in juice reject co-digested sludge. While restaurant food waste increased concentrations of K and Ca, both of which may be beneficial when applied to land. All metals in this study were below the maximum permissible concentrations specified for agricultural land use in Australia. Environmental risk assessment of sludge when used as soil fertiliser, showed that caffeine, diuron, triclocarban, triclosan, Cu and Zn exhibited high risks, with the largest risk quotient (RQ) posed by caffeine. Estrone and naproxen implied medium risks, and ibuprofen implied a high risk except for the co-digestion using cola reject (RQ = 0.9, medium risk). The results emphasise the importance for wastewater utility operators to understand the impact of co-substrate selection on the quality of sludge to minimise environmental risk from the use of biosolids on agricultural land.

This study uses a new approach for the recycling of plant nutrients by co-digesting sewage sludgewith fly ash from a wood combustion. Sewage sludge and fly ash both are enriched with nutrientsof the wastewater resp. wood, which makes these products an enhanced source for recycledfertilizers. The effects of the ash addition to the anaerobic digestion are studied in several labscale experiments including effects on the gas production and microbial activity. Following that,the fertilizing qualities of the digestate are evaluated by plant growth experiments. The resultsshow that the fertilizing qualities of the digested sludge were improved by the ash addition.Next to this, gas production results show that the methane production was not affected by theash addition, while the total gas release was reduced. The sulphur addition by the ashstimulated sulphate reducing bacteria. The sulphate reducing bacteria did not markedly inhibitthe methanogens., Validerad;2022;Nivå 2;2022-05-06 (hanlid)

This study uses a new approach for the recycling of plant nutrients by co-digesting sewage sludgewith fly ash from a wood combustion. Sewage sludge and fly ash both are enriched with nutrientsof the wastewater resp. wood, which makes these products an enhanced source for recycledfertilizers. The effects of the ash addition to the anaerobic digestion are studied in several labscale experiments including effects on the gas production and microbial activity. Following that,the fertilizing qualities of the digestate are evaluated by plant growth experiments. The resultsshow that the fertilizing qualities of the digested sludge were improved by the ash addition.Next to this, gas production results show that the methane production was not affected by theash addition, while the total gas release was reduced. The sulphur addition by the ashstimulated sulphate reducing bacteria. The sulphate reducing bacteria did not markedly inhibitthe methanogens., Validerad;2022;Nivå 2;2022-05-06 (hanlid)

Food waste (FW) is a primary constituent of solid waste and its adequate management is a global challenge. Instead of disposal in landfills, integrated treatment of FW with wastewater (WW) can diminish both environmental and economic burdens. Utilizing steady-state modelling and life cycle assessment techniques, this study investigated the prospects of FW integration with biological WW treatment in terms of WW treatment performance, net energy and carbon footprint and economics of the process. The explored scenarios include co-disposal and treatment with WW by using FW disposers and anaerobic co-digestion with sewage sludge in Hong Kong. Compared to the existing WW and FW treatment, the integrated scenarios significantly improved the energy balance (~83–126%), net greenhouse gas emissions (~90%), and economics of operation, with permissible impact on WW treatment performance. Therefore, utilizing the surplus capacity of the existing WW treatment facilities, these integrated scenarios are a promising solution for sustainable development. © 2022 Elsevier B.V.

Food waste (FW) is a primary constituent of solid waste and its adequate management is a global challenge. Instead of disposal in landfills, integrated treatment of FW with wastewater (WW) can diminish both environmental and economic burdens. Utilizing steady-state modelling and life cycle assessment techniques, this study investigated the prospects of FW integration with biological WW treatment in terms of WW treatment performance, net energy and carbon footprint and economics of the process. The explored scenarios include co-disposal and treatment with WW by using FW disposers and anaerobic co-digestion with sewage sludge in Hong Kong. Compared to the existing WW and FW treatment, the integrated scenarios significantly improved the energy balance (~83–126%), net greenhouse gas emissions (~90%), and economics of operation, with permissible impact on WW treatment performance. Therefore, utilizing the surplus capacity of the existing WW treatment facilities, these integrated scenarios are a promising solution for sustainable development. © 2022 Elsevier B.V.

Anaerobic digestion is a widely employed technique that converts waste into biogas, which can be employed as renewable energy. To improve its efficiency, but also to treat recalcitrant waste, mixes involving several types of feedstock with different biodegradability rates are fed to the process. Finding the proper mix is difficult and involves extensive, long-lasting experimental work. This paper presents an approach which allows determining the mix with desired properties based on Biochemical Methane Potential (BMP) tests, chemical composition of the feedstocks and optimization. This procedure is illustrated based on experimental data gathered from BMP tests on leaves of linden, oak and maple, and meadow. Subsequently, a simple model is used to simulate the continuous operation of the process converting the proposed mixes into methane., SCOPUS: cp.p, info:eu-repo/semantics/published

The importance of green technologies is steadily growing. Salt-tolerant plants have been proposed as energy crops for cultivation on saline lands. Halophytes such as Salicornia europaea, Tripolium pannonicum, Crithmum maritimum and Chenopodium quinoa, among many other species, can be cultivated in saline lands, in coastal areas or for treating saline wastewater, and the biomass might be used for biogas production as an integrated process of biorefining. However, halophytes have different salt tolerance mechanisms, including compartmentalization of salt in the vacuole, leading to an increase of sodium in the plant tissues. The sodium content of halophytes may have an adverse effect on the anaerobic digestion process, which needs adjustments to achieve stable and efficient conversion of the halophytes into biogas. This review gives an overview of the specificities of halophytes that needs to be accounted for using their biomass as feedstocks for biogas plants in order to expand renewable energy production. First, the different physiological mechanisms of hal-ophytes to grow under saline conditions are described, which lead to the characteristic composition of the halophyte biomass, which may influence the biogas production. Next, possible mechanisms to avoid negative effects on the anaerobic digestion process are described, with an overview of full-scale applications. Taking all these aspects into account, halophyte plants have a great potential for biogas and methane production with yields similar to those produced by other energy crops and the simultaneous benefit of utilization of saline soils.

[Resumen]: Se lleva años investigando la producción de biocombustible a partir de residuos orgánicos y aguas residuales. La necesidad de buscar nuevas formas de energía renovable más limpias con el medioambiente es cada vez mayor. En los últimos años se han llevado a cabo diferentes investigaciones para mejorar la producción de biogás mediante digestión anaeróbica. Se han incluido el uso de diferentes tipos de pretratamientos que mejoran la digestión de la materia orgánica para un mejor desenvolvimiento del proceso y se ha estudiado la co-digestión de materias orgánicas de diversas naturalezas como alternativa para aumentar el rendimiento en la producción del biogás. En el presente trabajo se realizó un estudio bibliográfico general sobre la producción de biogás mediante digestión anaeróbica. Se investigó la problemática de los residuos de la industria MDF y la posibilidad de aplicar la digestión anaeróbica para el tratamiento de estos residuos, así como, las diferentes tecnologías utilizadas en digestión anaerobia. La producción de biogás a partir de residuos MDF está todavía en desarrollo por los diferentes inconvenientes que presentan estos residuos. De este modo, se decidió centralizar el objetivo del trabajo en el estudio de la co-digestión de materiales de origen lignocelulósico (forestal, papel, etc.) con el propósito de buscar nuevas formas para perfeccionar el proceso de digestión anaeróbica y, en consecuencia, mejorar la producción de biogás. La co-digestión es una estrategia eficaz y presenta mayor seguridad ambiental que algunos tipos de pre-tratamiento., [Resumo]: Lévase anos investigando a produción de biocombustibles a partir de residuos orgánicos e augas residuais. A necesidade de buscar novas formas de enerxía renovable máis limpas co medioambiente é cada vez maior. Nos últimos anos leváronse a cabo diferentes investigacións para mellorar a produción de biogás mediante dixestión anaerobia. Incluíuse o uso de diferentes tipos de pre-tratamentos que melloran a dixestión da materia orgánica para un mellor desenvolvemento do proceso e estudouse a co-dixestión de materias orgánicas de diversas naturezas como alternativa para aumentar o rendemento na produción do biogás. No presente traballo realizouse un estudo bibliográfico xeral sobre a produción de biogás mediante dixestión anaerobia. Investigouse a problemática dos residuos da industria MDF e a posibilidade de aplicar a dixestión anaerobia para o tratamento destes residuos, así como tamén, as diferentes tecnoloxías usadas na dixestión anaerobia. A produción de biogás a partir de residuos MDF está aínda en desenvolvemento polos distintos impedimentos que presentan ditos residuos. Deste modo, decidiuse centrar o obxectivo do traballo no estudo da co-dixestión de materiais de orixe lignocelulósico (forestal, papel, etc.) co propósito de buscar novas formas para perfeccionar o proceso de dixestión anaerobia e, en consecuencia, mellorar a produción de biogás. A codixestión é una estratexia eficaz e presenta maior seguridade ambiental que algúns tipos de pre-tratamento. Palabras, [Abstract]: Biofuel production from organic waste and wastewaters has been researched for years. The need to seek new forms of renewable energy cleaner with the environment is increasing. In recent years, different investigations have been carried out to improve biogas production through anaerobic digestion. The use of different types of pretreatments have been included that improve the digestion of organic matter for a better development of the process and the co-digestion of organic matter of different natures has been studied as an alternative to increase the yield in the production of the biogas. In the present work, a general bibliographic study on biogas production by anaerobic digestion was carried out. The problem of waste from the MDF industry and the possibility of applying anaerobic digestion to treat these wastes, as well as the different technologies used in anaerobic digestion, were investigated. The production of biogas from MDF waste is still under development due to the different inconveniences that these waste present. So, it was decided to centralize the objective of the work in the study of the co-digestion of materials of lignocellulosic origin (forest, paper, etc.) with the purpose of looking for new ways to improve the anaerobic digestion process and, consequently, improve biogas production. Co-digestion is an effective strategy and presents greater environmental safety than some types of pre-treatments.

Small-scale electrical power generation (<100 kW) from biogas plants to provide off-grid electricity is of growing interest. Currently, gas engines are used to meet this demand. Alternatively, more efficient small-scale solid oxide fuel cells (SOFCs) can be used to enhance electricity generation from small-scale biogas plants. Most electricity generators require a constant gas supply and high gas quality in terms of absence of impurities like H 2S. Therefore, to efficiently use the biogas from existing decentralized anaerobic digesters for electricity production, higher quality and stable biogas flow must be guaranteed. The installation of a biogas upgrading and buffer system could be considered; however, the cost implication could be high at a small scale as compared to locally available alterna-tives such as co-digestion and improved digester operation. Therefore, this study initially describes relevant literature related to feedstock pre-treatment, co-digestion and user operational practices of small-scale digesters, which theoretically could lead to major improvements of anaerobic digestion process efficiency. The theoretical preamble is then coupled to the results of a field study, which demonstrated that many locally available resources and user practices constitute frugal innovations with potential to improve biogas quality and digester performance in off-grid settings., Sanitary Engineering, Energy Technology

Der fortschreitende Klimawandel und der zunehmende Verbrauch an Ressourcen erfordern dringenden Handlungsbedarf zur Reduzierung der umwelt- und klimaschädlichen Einflüsse. Insbesondere kommt hier der Energieerzeugung aus erneuerbaren Quellen und deren Ausbau eine besondere Bedeutung zu, um die politischen Zielvorgaben zur Minderung von Treibhausgasemissionen zu erreichen. Um die nationalen und internationalen Klimaziele zu erfüllen, müssen sämtliche erneuerbare Energiequellen genutzt werden. Zur Nutzbarmachung des Energiepotenzials von Klärschlämmen verfügen Kläranlagen über Faultürme in denen die bei der Abwasserreinigung anfallenden Klärschlämme vergoren werden. Aus dem Vergärungsprozess entsteht Faulgas, das zur Gewinnung von Strom und Wärme genutzt werden kann. Aufgrund freier Kapazitäten verarbeiten Kläranlagen weitere organische Reststoffe, die sogenannten Co-Substrate, und können so die Energieproduktion aus erneuerbaren Quellen erhöhen. Als Co-Substrate werden beispielweise Küchen- und Speiseabfälle oder Lebensmittelabfälle aus Supermärkten eingesetzt. Gerade in Regionen, welche stark vom Tourismus geprägt sind, ist der Anfall und die Menge solcher Reststoffe aufgrund der Saisonalität sehr schwankend. Deshalb spielt die Zwischenspeicherung bei der Vergärung dieser Substrate eine wesentliche Rolle. Gleichzeitig erfordert der Einsatz von Co-Substraten neben der Bestimmung einer möglichen zusätzlichen Rückbelastung der Wasserlinie und des zusätzlichen Arbeitsaufwands eine genaue Kenntnis darüber, welche Methanerträge aus diesen Substraten erzielt werden und wie hoch der Reststoffanfall nach Vergärung ausfällt. Sofern diese Informationen vorliegen, kann die Gesamtwirtschaftlichkeit einer Co-Vergärung beurteilt werden. Ziel dieser Arbeit war es einerseits, die Lagerung bzw. Zwischenspeicherung von Co-Substraten zu untersuchen. Dies umfasste das Lagerungsverhalten der Co-Substrate in labor- und großtechnischen Untersuchungen sowie einer Betrachtung der Lagerung vo, Climate change and the increasing consumption of resources require urgent actions to reduce harmful impacts on the environment and the climate. In particular, energy generation from renewable sources and its expansion are of special importance in order to achieve the political targets for the reduction of greenhouse gas emissions. To meet the climate targets, all renewable energy sources have to be exploited. Wastewater treatment plants (WWTP) utilize the sewage sludge generated during the wastewater treatment process in anaerobic digesters for biogas production, thus making their energy potential available. The biogas can be used to generate electricity and heat. Due to free capacities, WWTP digest additional organic residues, so-called co-substrates, to increase energy production from renewable sources. Examples of co-substrates are kitchen and food waste or food waste from supermarkets. Especially in touristic regions, the quantity of co-substrates can fluctuate greatly due to seasonality. Therefore, intermediate storage plays an essential role when digesting such substrates in WWTP digesters. At the same time, the use of co-substrates requires knowledge of their methane yields and the amounts of residues left after AD. If this information is available, the overall economic efficiency of co-digestion can be assessed. The aim of this work is, on the one hand, to investigate the pre-requisites and consequences of the storage of co-substrates. This included the storage behaviour of co-substrates in laboratory and field experiments as well as considerations related to the storage of co-substrates for the storage of energy. In a further step, the basic data for an economic analysis of co-digestion were determined in laboratory and full-scale investigations. Different balancing approaches were used to determine methane and digestate production from co-substrates. The experiments on the storage of co-substrates showed a conservation of the organic waste and an energy de, Dipl.-Ing. (FH) Marco Wehner (geb. Genslein), M.Sc., Abweichender Titel laut Übersetzung der Verfasserin/des Verfassers, Kumulative Arbeit mit 4 Artikeln, Dissertation Universität Innsbruck 2021, Kurzfassung deutsch und englisch

Der fortschreitende Klimawandel und der zunehmende Verbrauch an Ressourcen erfordern dringenden Handlungsbedarf zur Reduzierung der umwelt- und klimaschädlichen Einflüsse. Insbesondere kommt hier der Energieerzeugung aus erneuerbaren Quellen und deren Ausbau eine besondere Bedeutung zu, um die politischen Zielvorgaben zur Minderung von Treibhausgasemissionen zu erreichen. Um die nationalen und internationalen Klimaziele zu erfüllen, müssen sämtliche erneuerbare Energiequellen genutzt werden. Zur Nutzbarmachung des Energiepotenzials von Klärschlämmen verfügen Kläranlagen über Faultürme in denen die bei der Abwasserreinigung anfallenden Klärschlämme vergoren werden. Aus dem Vergärungsprozess entsteht Faulgas, das zur Gewinnung von Strom und Wärme genutzt werden kann. Aufgrund freier Kapazitäten verarbeiten Kläranlagen weitere organische Reststoffe, die sogenannten Co-Substrate, und können so die Energieproduktion aus erneuerbaren Quellen erhöhen. Als Co-Substrate werden beispielweise Küchen- und Speiseabfälle oder Lebensmittelabfälle aus Supermärkten eingesetzt. Gerade in Regionen, welche stark vom Tourismus geprägt sind, ist der Anfall und die Menge solcher Reststoffe aufgrund der Saisonalität sehr schwankend. Deshalb spielt die Zwischenspeicherung bei der Vergärung dieser Substrate eine wesentliche Rolle. Gleichzeitig erfordert der Einsatz von Co-Substraten neben der Bestimmung einer möglichen zusätzlichen Rückbelastung der Wasserlinie und des zusätzlichen Arbeitsaufwands eine genaue Kenntnis darüber, welche Methanerträge aus diesen Substraten erzielt werden und wie hoch der Reststoffanfall nach Vergärung ausfällt. Sofern diese Informationen vorliegen, kann die Gesamtwirtschaftlichkeit einer Co-Vergärung beurteilt werden. Ziel dieser Arbeit war es einerseits, die Lagerung bzw. Zwischenspeicherung von Co-Substraten zu untersuchen. Dies umfasste das Lagerungsverhalten der Co-Substrate in labor- und großtechnischen Untersuchungen sowie einer Betrachtung der Lagerung vo, Climate change and the increasing consumption of resources require urgent actions to reduce harmful impacts on the environment and the climate. In particular, energy generation from renewable sources and its expansion are of special importance in order to achieve the political targets for the reduction of greenhouse gas emissions. To meet the climate targets, all renewable energy sources have to be exploited. Wastewater treatment plants (WWTP) utilize the sewage sludge generated during the wastewater treatment process in anaerobic digesters for biogas production, thus making their energy potential available. The biogas can be used to generate electricity and heat. Due to free capacities, WWTP digest additional organic residues, so-called co-substrates, to increase energy production from renewable sources. Examples of co-substrates are kitchen and food waste or food waste from supermarkets. Especially in touristic regions, the quantity of co-substrates can fluctuate greatly due to seasonality. Therefore, intermediate storage plays an essential role when digesting such substrates in WWTP digesters. At the same time, the use of co-substrates requires knowledge of their methane yields and the amounts of residues left after AD. If this information is available, the overall economic efficiency of co-digestion can be assessed. The aim of this work is, on the one hand, to investigate the pre-requisites and consequences of the storage of co-substrates. This included the storage behaviour of co-substrates in laboratory and field experiments as well as considerations related to the storage of co-substrates for the storage of energy. In a further step, the basic data for an economic analysis of co-digestion were determined in laboratory and full-scale investigations. Different balancing approaches were used to determine methane and digestate production from co-substrates. The experiments on the storage of co-substrates showed a conservation of the organic waste and an energy de, Dipl.-Ing. (FH) Marco Wehner (geb. Genslein), M.Sc., Abweichender Titel laut Übersetzung der Verfasserin/des Verfassers, Kumulative Arbeit mit 4 Artikeln, Dissertation Universität Innsbruck 2021, Kurzfassung deutsch und englisch

Small-scale electrical power generation (<100 kW) from biogas plants to provide off-grid electricity is of growing interest. Currently, gas engines are used to meet this demand. Alternatively, more efficient small-scale solid oxide fuel cells (SOFCs) can be used to enhance electricity generation from small-scale biogas plants. Most electricity generators require a constant gas supply and high gas quality in terms of absence of impurities like H 2S. Therefore, to efficiently use the biogas from existing decentralized anaerobic digesters for electricity production, higher quality and stable biogas flow must be guaranteed. The installation of a biogas upgrading and buffer system could be considered; however, the cost implication could be high at a small scale as compared to locally available alterna-tives such as co-digestion and improved digester operation. Therefore, this study initially describes relevant literature related to feedstock pre-treatment, co-digestion and user operational practices of small-scale digesters, which theoretically could lead to major improvements of anaerobic digestion process efficiency. The theoretical preamble is then coupled to the results of a field study, which demonstrated that many locally available resources and user practices constitute frugal innovations with potential to improve biogas quality and digester performance in off-grid settings., Sanitary Engineering, Energy Technology

[Resumen]: Se lleva años investigando la producción de biocombustible a partir de residuos orgánicos y aguas residuales. La necesidad de buscar nuevas formas de energía renovable más limpias con el medioambiente es cada vez mayor. En los últimos años se han llevado a cabo diferentes investigaciones para mejorar la producción de biogás mediante digestión anaeróbica. Se han incluido el uso de diferentes tipos de pretratamientos que mejoran la digestión de la materia orgánica para un mejor desenvolvimiento del proceso y se ha estudiado la co-digestión de materias orgánicas de diversas naturalezas como alternativa para aumentar el rendimiento en la producción del biogás. En el presente trabajo se realizó un estudio bibliográfico general sobre la producción de biogás mediante digestión anaeróbica. Se investigó la problemática de los residuos de la industria MDF y la posibilidad de aplicar la digestión anaeróbica para el tratamiento de estos residuos, así como, las diferentes tecnologías utilizadas en digestión anaerobia. La producción de biogás a partir de residuos MDF está todavía en desarrollo por los diferentes inconvenientes que presentan estos residuos. De este modo, se decidió centralizar el objetivo del trabajo en el estudio de la co-digestión de materiales de origen lignocelulósico (forestal, papel, etc.) con el propósito de buscar nuevas formas para perfeccionar el proceso de digestión anaeróbica y, en consecuencia, mejorar la producción de biogás. La co-digestión es una estrategia eficaz y presenta mayor seguridad ambiental que algunos tipos de pre-tratamiento., [Resumo]: Lévase anos investigando a produción de biocombustibles a partir de residuos orgánicos e augas residuais. A necesidade de buscar novas formas de enerxía renovable máis limpas co medioambiente é cada vez maior. Nos últimos anos leváronse a cabo diferentes investigacións para mellorar a produción de biogás mediante dixestión anaerobia. Incluíuse o uso de diferentes tipos de pre-tratamentos que melloran a dixestión da materia orgánica para un mellor desenvolvemento do proceso e estudouse a co-dixestión de materias orgánicas de diversas naturezas como alternativa para aumentar o rendemento na produción do biogás. No presente traballo realizouse un estudo bibliográfico xeral sobre a produción de biogás mediante dixestión anaerobia. Investigouse a problemática dos residuos da industria MDF e a posibilidade de aplicar a dixestión anaerobia para o tratamento destes residuos, así como tamén, as diferentes tecnoloxías usadas na dixestión anaerobia. A produción de biogás a partir de residuos MDF está aínda en desenvolvemento polos distintos impedimentos que presentan ditos residuos. Deste modo, decidiuse centrar o obxectivo do traballo no estudo da co-dixestión de materiais de orixe lignocelulósico (forestal, papel, etc.) co propósito de buscar novas formas para perfeccionar o proceso de dixestión anaerobia e, en consecuencia, mellorar a produción de biogás. A codixestión é una estratexia eficaz e presenta maior seguridade ambiental que algúns tipos de pre-tratamento. Palabras, [Abstract]: Biofuel production from organic waste and wastewaters has been researched for years. The need to seek new forms of renewable energy cleaner with the environment is increasing. In recent years, different investigations have been carried out to improve biogas production through anaerobic digestion. The use of different types of pretreatments have been included that improve the digestion of organic matter for a better development of the process and the co-digestion of organic matter of different natures has been studied as an alternative to increase the yield in the production of the biogas. In the present work, a general bibliographic study on biogas production by anaerobic digestion was carried out. The problem of waste from the MDF industry and the possibility of applying anaerobic digestion to treat these wastes, as well as the different technologies used in anaerobic digestion, were investigated. The production of biogas from MDF waste is still under development due to the different inconveniences that these waste present. So, it was decided to centralize the objective of the work in the study of the co-digestion of materials of lignocellulosic origin (forest, paper, etc.) with the purpose of looking for new ways to improve the anaerobic digestion process and, consequently, improve biogas production. Co-digestion is an effective strategy and presents greater environmental safety than some types of pre-treatments.

[EN] Methane production from microalgae can be enhanced through anaerobic co-digestion with carbon-rich substrates and thus mitigate the inhibition risk associated with its low C:N ratio. Acclimated microbial communities for microalgae disruption can be used as a source of natural enzymes in bioenergy production. However, co-substrates with a certain microbial diversity such as primary sludge might shift the microbial structure. Substrates were generated in a Water Resource Recovery Facility (WRRF) and combined as follows: Scenedesmus or Chlorella digestion and microalgae co-digestion with primary sludge. The study was performed using two lab-scale Anaerobic Membrane Bioreactors (AnMBR). During three years, different feedstocks scenarios for methane production were evaluated with a special focus on the microbial diversity of the AnMBR. 57% of the population was shared between the different feedstock scenarios, revealing the importance of Anaerolineaceae members besides Smithella and Methanosaeta genera. The addition of primary sludge enhanced the microbial diversity of the system during both Chlorella and Scenedesmus co-digestion and promoted different microbial structures. Aceticlastic methanogen Methanosaeta was dominant in all the feedstock scenarios. A more remarkable role of syntrophic fatty acid degraders (Smithella, Syntrophobacteraceae) was observed during co-digestion when only microalgae were digested. However, no significant changes were observed in the microbial composition during anaerobic microalgae digestion when feeding only Chlorella or Scenedesmus. This is the first work revealing the composition of complex communities for semi-continuous bioenergy production from WRRF streams. The stability and maintenance of a microbial core over-time in semi-continuous AnMBRs is here shown supporting their future application in full-scale systems for raw microalgae digestion or codigestion.

The focus of the current study was on the recovery of carbon from municipal bio-waste streams. Firstly, the relationship between methanogenic pathways and the properties of anaerobic granules was studied using two pilot-scale upflow anaerobic sludge blanket (UASB) reactors with different granule size distribution. UASB1 granules were larger (3-4 mm) with multi-layered internal structure and the archaeal community was dominated by acetoclastic methanogens, while the UASB2 granules were smaller (1-2 mm) without a layered internal structure and the archaeal community was predominated by hydrogenotrophic methanogens. The acetoclastic methanogenic activities of UASB1 (250-437 mL CH4/g VS·d) than UASB2 (150-260 mL CH4/g VS·d), confirming that acetoclastic methanogenesis was more dominant in UASB1. Temperature increase from 20oC to 28oC did not change the microbial community but resulted in increased and stable biogas production for both reactors. There was an increase in chemical oxygen demand (COD) with hydraulic retention time due to increased contact time. The second part of the study focused on anaerobic co-digestion to produce volatile fatty acid (VFA) due to its higher value. The impact of substrate ratio of primary sludge (PS) and external organic waste (OW) and the robustness of the VFA system in the long term were assessed. Lab-scale batch study with different proportions of PS and OW; 0%, 25%, 50%, 75%, 100% of OW in terms of COD and scaled up in a semi-continuous pilot reactor with substrate ratio of 50% OW based on the results of the lab-scale study were performed. There was an increase in VFA production with an increase in OW proportion due to the availability of biodegradable organics. Acetic acid was the most dominant VFA in the batch reactors while in the semi-continuous experiment, caproic acid was dominated (50%). As carbon sources, the VFA-rich liquid attained the highest specific denitrification rate when compared with acetate and methanol., I kommunala avfallsströmmar finns det en stor potential för resursåtervinning på grund av det höga organiska innehållet vilket kan användas för biobaserade produkter. På grundval av detta så fokuserar denna studie på resursåtervinningen av kol från kommunala avfallsströmmar genom att undersöka nuvarande och nytillkomna tekniker för att få vattenreningssystem att också bli resursåtervinningssystem. Första delen av studien undersöker relationen mellan metanproduktion och karaktäriseringen av anaerobiska granuler med ändamålet att förbättra energiproduktionen genom direkt behandling av kommunalt avloppsvatten. För detta ändamål så användes två UASB (Upflow Anaerobic Sludge Blanket) pilotreaktorer. Reaktorerna kördes med olika stora granuler, olika temperaturinställningar och olika hydrauliska uppehållstider (HRTs). Storlek, mikrobiell struktur, intern mikrostruktur och specifik metanogenaktivitet av de anaerobiska granulerna analyserades. Granulerna i UASB1 var 3-4 mm stora med interna multilager av mikrostrukturer som bestod av acetoklastika-metanogen arkéer. Granulerna i UASB2 var 1- 2 mm stora utan interna multilager och bestod av hydrogenotrofa metanogener. Aktiviteten i granulerna i UASB1 var 250-437 mL CH4 /g VS·d och i UASB2 var det 150-260 mL CH4 /g VS·d, vilket bekräftar att de acetoklastisk-metanogesa var mer effektiva i UASB1 än de hydrogenotrofa i UASB2. Att öka temperaturen från 20 o C till 28 o C under försöket medförde ingen förändring av den mikrobiologiska strukturen, men gav en ökning i biogasproduktion i UASB1 och högre och stabilare biogasproduktionshastighet i UASB2. Ökningen av biogasproduktion berodde på en reduktion i metans löslighet i utflödet och stabilare metanogenes. Ökning i HRT resulterade i större reduktion av organiskt material mätt som kemisk syreförbrukning (COD) och större biogasproduktion på grund av längre kontakttid mellan substrat och mikroorganismer. Den andra delen av studien fokuserar på att utveckla ett tillvägagångssätt att, QC 2020-06-15

The focus of the current study was on the recovery of carbon from municipal bio-waste streams. Firstly, the relationship between methanogenic pathways and the properties of anaerobic granules was studied using two pilot-scale upflow anaerobic sludge blanket (UASB) reactors with different granule size distribution. UASB1 granules were larger (3-4 mm) with multi-layered internal structure and the archaeal community was dominated by acetoclastic methanogens, while the UASB2 granules were smaller (1-2 mm) without a layered internal structure and the archaeal community was predominated by hydrogenotrophic methanogens. The acetoclastic methanogenic activities of UASB1 (250-437 mL CH4/g VS·d) than UASB2 (150-260 mL CH4/g VS·d), confirming that acetoclastic methanogenesis was more dominant in UASB1. Temperature increase from 20oC to 28oC did not change the microbial community but resulted in increased and stable biogas production for both reactors. There was an increase in chemical oxygen demand (COD) with hydraulic retention time due to increased contact time. The second part of the study focused on anaerobic co-digestion to produce volatile fatty acid (VFA) due to its higher value. The impact of substrate ratio of primary sludge (PS) and external organic waste (OW) and the robustness of the VFA system in the long term were assessed. Lab-scale batch study with different proportions of PS and OW; 0%, 25%, 50%, 75%, 100% of OW in terms of COD and scaled up in a semi-continuous pilot reactor with substrate ratio of 50% OW based on the results of the lab-scale study were performed. There was an increase in VFA production with an increase in OW proportion due to the availability of biodegradable organics. Acetic acid was the most dominant VFA in the batch reactors while in the semi-continuous experiment, caproic acid was dominated (50%). As carbon sources, the VFA-rich liquid attained the highest specific denitrification rate when compared with acetate and methanol., I kommunala avfallsströmmar finns det en stor potential för resursåtervinning på grund av det höga organiska innehållet vilket kan användas för biobaserade produkter. På grundval av detta så fokuserar denna studie på resursåtervinningen av kol från kommunala avfallsströmmar genom att undersöka nuvarande och nytillkomna tekniker för att få vattenreningssystem att också bli resursåtervinningssystem. Första delen av studien undersöker relationen mellan metanproduktion och karaktäriseringen av anaerobiska granuler med ändamålet att förbättra energiproduktionen genom direkt behandling av kommunalt avloppsvatten. För detta ändamål så användes två UASB (Upflow Anaerobic Sludge Blanket) pilotreaktorer. Reaktorerna kördes med olika stora granuler, olika temperaturinställningar och olika hydrauliska uppehållstider (HRTs). Storlek, mikrobiell struktur, intern mikrostruktur och specifik metanogenaktivitet av de anaerobiska granulerna analyserades. Granulerna i UASB1 var 3-4 mm stora med interna multilager av mikrostrukturer som bestod av acetoklastika-metanogen arkéer. Granulerna i UASB2 var 1- 2 mm stora utan interna multilager och bestod av hydrogenotrofa metanogener. Aktiviteten i granulerna i UASB1 var 250-437 mL CH4 /g VS·d och i UASB2 var det 150-260 mL CH4 /g VS·d, vilket bekräftar att de acetoklastisk-metanogesa var mer effektiva i UASB1 än de hydrogenotrofa i UASB2. Att öka temperaturen från 20 o C till 28 o C under försöket medförde ingen förändring av den mikrobiologiska strukturen, men gav en ökning i biogasproduktion i UASB1 och högre och stabilare biogasproduktionshastighet i UASB2. Ökningen av biogasproduktion berodde på en reduktion i metans löslighet i utflödet och stabilare metanogenes. Ökning i HRT resulterade i större reduktion av organiskt material mätt som kemisk syreförbrukning (COD) och större biogasproduktion på grund av längre kontakttid mellan substrat och mikroorganismer. Den andra delen av studien fokuserar på att utveckla ett tillvägagångssätt att, QC 2020-06-15

[EN] Methane production from microalgae can be enhanced through anaerobic co-digestion with carbon-rich substrates and thus mitigate the inhibition risk associated with its low C:N ratio. Acclimated microbial communities for microalgae disruption can be used as a source of natural enzymes in bioenergy production. However, co-substrates with a certain microbial diversity such as primary sludge might shift the microbial structure. Substrates were generated in a Water Resource Recovery Facility (WRRF) and combined as follows: Scenedesmus or Chlorella digestion and microalgae co-digestion with primary sludge. The study was performed using two lab-scale Anaerobic Membrane Bioreactors (AnMBR). During three years, different feedstocks scenarios for methane production were evaluated with a special focus on the microbial diversity of the AnMBR. 57% of the population was shared between the different feedstock scenarios, revealing the importance of Anaerolineaceae members besides Smithella and Methanosaeta genera. The addition of primary sludge enhanced the microbial diversity of the system during both Chlorella and Scenedesmus co-digestion and promoted different microbial structures. Aceticlastic methanogen Methanosaeta was dominant in all the feedstock scenarios. A more remarkable role of syntrophic fatty acid degraders (Smithella, Syntrophobacteraceae) was observed during co-digestion when only microalgae were digested. However, no significant changes were observed in the microbial composition during anaerobic microalgae digestion when feeding only Chlorella or Scenedesmus. This is the first work revealing the composition of complex communities for semi-continuous bioenergy production from WRRF streams. The stability and maintenance of a microbial core over-time in semi-continuous AnMBRs is here shown supporting their future application in full-scale systems for raw microalgae digestion or codigestion.

The water, food and energy nexus is a vital subject to achieve sustainable development goals worldwide. Wastewater (WW) and food waste (FW) from municipal sources are the primary contributors of organic waste from cities. Along with the loss of these valuable natural resources, their treatment systems also consume a considerable amount of abiotic energy and resource input and make a perceptible contribution to global warming. Hence, the global paradigm has evolved from simple pollution mitigation to resource recovery systems. In this study, the prospects of FW co-disposal into the sewer system and treatment with municipal sewage were quantitatively investigated for Hong Kong's largest biological WW treatment plant (WWTP) by integrated plant-wide steady-state modelling (PWSSM) and lifecycle assessment (LCA) approaches. The investigation assessed the impacts on the design and operational capacity of the WWTP, effluent quality, sludge output, and its net energy and carbon footprint. The results revealed that even at a higher than normal FW to sewage ratio, the WWTP's organic load capacity and performance in terms of organics and nitrogen removal was not significantly degraded, in fact the denitrification efficiency was improved by the FW organics with low N/C ratio. The net energy balance was improved by 80-400%, the net carbon footprint was lowered by 37-63% (without biogenic emissions), while the sludge production was increased by ∼33%. The results are very sensitive and improved with greater influent FW concentration and solids capture in the primary settling unit of the WWTP. The differences in the results have to be seen in relation to uncontrolled methane emission and a faster filling rate if the FW were disposed to landfill. The study provides valuable insights and policy guidelines for the decision makers locally and a generic methodological template.

Full Text, Thesis (Masters), Master of Philosophy (MPhil), School of Eng & Built Env, Science, Environment, Engineering and Technology, Australia is one of the major producers and exporter of agricultural products. Annually, Australian agriculture produces approximately 151 Tg CO2 equivalent emissions. The use of fossil fuels in crop cultivation, harvesting and transportation are considered as the primary source of these greenhouse gas (GHG) emissions. Moreover, agronomic management and crop residues left in the field also contribute to these GHG emissions. Alternative waste management practices include the use of crop residues and agro-wastes as feedstocks for bioenergy production. Anaerobic digestion is considered as sustainable environmental technology to convert industrial sugarcane residues to carbon dioxide (CO2) - neutral biogas. The biogas thus produced can be used to produce heat, electricity and upgrade to biomethane for vehicle use. The produced biomethane can replace the diesel consumption associated with GHG emission in cane transport. Sugarcane is one among the most cultivated crop in the world. Australia alone produced nearly 33.5 million tonnes of cane in 2018 (FAO 2018). These large production of sugarcane lead to an increase in crop residues and agro-wastes from the sugarcane industry. In this study, an investigation regarding the anaerobic co-digestion of crop residues and agro-wastes from sugarcane industry viz, sugarcane trash (SCT) or sugarcane bagasse (SCB) with chicken manure (CM) was investigated in a batch experiment at 37 °C. In spite of various researches conducted till date about co-digestion of lignocellulosic waste with manure, no research data was available regarding the effect of feed ratio on co-digestion of SCT/SCB with CM. This research gap was investigated in this study. In addition to this, steam explosion pre-treatment of SCT/SCB was included to investigate how the pre-treatment influence methane yield among different feed ratios of SCT/SCB with CM. At first, SCT and SCB were subjected to steam explosion pre-treatment (steam impregnation at 130 °C for 5 minutes

The water, food and energy nexus is a vital subject to achieve sustainable development goals worldwide. Wastewater (WW) and food waste (FW) from municipal sources are the primary contributors of organic waste from cities. Along with the loss of these valuable natural resources, their treatment systems also consume a considerable amount of abiotic energy and resource input and make a perceptible contribution to global warming. Hence, the global paradigm has evolved from simple pollution mitigation to resource recovery systems. In this study, the prospects of FW co-disposal into the sewer system and treatment with municipal sewage were quantitatively investigated for Hong Kong's largest biological WW treatment plant (WWTP) by integrated plant-wide steady-state modelling (PWSSM) and lifecycle assessment (LCA) approaches. The investigation assessed the impacts on the design and operational capacity of the WWTP, effluent quality, sludge output, and its net energy and carbon footprint. The results revealed that even at a higher than normal FW to sewage ratio, the WWTP's organic load capacity and performance in terms of organics and nitrogen removal was not significantly degraded, in fact the denitrification efficiency was improved by the FW organics with low N/C ratio. The net energy balance was improved by 80-400%, the net carbon footprint was lowered by 37-63% (without biogenic emissions), while the sludge production was increased by ∼33%. The results are very sensitive and improved with greater influent FW concentration and solids capture in the primary settling unit of the WWTP. The differences in the results have to be seen in relation to uncontrolled methane emission and a faster filling rate if the FW were disposed to landfill. The study provides valuable insights and policy guidelines for the decision makers locally and a generic methodological template.

Urban solid waste (MSW), when are discharged without proper treatment, causes severe damage to the environment, influencing the population's quality of life. For this reason, attention is currently paid to the proper handling of this waste. This paper studies the reduction of the organic fraction of solid waste (OFMSW), generated by a population group, taking as reference one of the Student Residences of the Universidad de Oriente. The generation of OFMSW in the residence is 0.06 kg/inhab-day, with a total solid content of 30.9 ± 5.3%, of which 81.7 ± 0.6% are volatile solids. The anaerobic digestion of OFMSW is evaluated through a two-stage treatment system. The first stage is performed in a drained-bed batch reactor, which allowed discontinuous and in-situ treatment of OFMSW, in anaerobic co-digestion with 25% of cow manure. In a second stage, the anaerobic treatment for the leachates generated in the batch reactor is evaluated, using a UASB reactor. In the batch reactor a removal of volatile solids of 44.1% was achieved, while in the UASB reactor 81.2% of COD was removed. As a result of the evaluation of the treatment system, total productivity of 5.37 L CH4 -kgSV-1·d-1 was achieved., Los residuos sólidos urbanos (RSU), al ser vertidos sin tratamiento adecuado, ocasionan daños severos al ambiente influyendo en la calidad de vida de la población, razón por la cual actualmente se le presta atención diferenciada al vertido de residuos urbanos. En este trabajo se evalúa la fracción orgánica de estos residuos (FORSU), tomando como referencia el grupo poblacional de una de las Residencias estudiantiles de la Universidad de Oriente. La generación de FORSU en la residencia es de 0,06 kg/hab/día, con un contenido de sólidos totales de 30,9 ± 5,3 % de los cuáles el 81,7 ± 0,6 % son sólidos volátiles. Se evalúa el funcionamiento de un reactor en lote de lecho escurrido, que permitió un tratamiento discontinuo e in situ de la FORSU, en codigestión anaerobia con un 25 % de estiércol vacuno en una primera etapa. También se evalúa, en una segunda etapa, el tratamiento anaerobio para los lixiviados que se generan en el reactor en lote, empleando un reactor UASB. En el reactor en lote se alcanzó una remoción de sólidos volátiles del 44,1 %, mientras que en el reactor UASB se removió un 81,2 % de DQO. Como resultado del sistema de tratamiento evaluado, se alcanzó una productividad total de 5,37 LCH4·kgSV-1·d-1., resíduos sólidos urbanos (RSU), a ser descarregada sem tratamento adequado, causando graves danos ao meio ambiente influenciam a qualidade de vida da população, razão pela qual ele está atualmente fornecendo atenção diferenciada à descarga de resíduos urbanos. Neste trabalho é avaliada a fração orgânica desses resíduos (FORSU), tomando como referência o grupo populacional de uma Residência Estudantil da Universidade de Oriente. A geração de FORSU na residência é de 0,06 kg / hab / dia, com um teor total de sólidos de 30,9 ± 5,3%, dos quais 81,7 ± 0,6% são sólidos voláteis. execução de um reactor descontínuo de leito gotejar, o que permitiu um tratamento em lotes é avaliada e em FORSU situ em Co-digestão anaeróbia, com 25% de estrume de vaca numa primeira fase. Também avalia, em uma segunda etapa, o tratamento anaeróbio para os lixiviados que são gerados no reator em lotes, usando um reator UASB. No reator em lotes foi alcançada uma remoção de sólidos voláteis de 44,1%, enquanto que no reator UASB 81,2% de DQO foram removidos. Como resultado do sistema de tratamento avaliado, atingiu-se uma produtividade total de 5.37 LCH4 · kgSV-1 · d-1.

Even though the Brazilian ethanol and sugar production system (based on sugarcane industry) have been providing large amounts of bioenergy, the extensive amounts of organic wastes generated cannot be ignored when it comes to sustainability. Using these biomasses to produce biomethane through anaerobic digestion has been proven as a promising way to tackle this issue. This study investigated the biomethane potential of the co-digestion of these biomasses: SF (sugarcane straw : filter cake = 8:2), SFV (sugarcane straw : filter cake : vinasse = 1:4:45), and D (digestate separated from AD of SFV). Three treatments autoclaving (AU), alkaline (AL) treatment using 6% (w/w) NaOH and the combination of these two (AUAL) were then conducted on SF and SFV as pre-treatments; on D as post- treatments. In the biomethane potential tests of untreated material, the highest methane yield was achieved by SFV with 275.28 ± 11 N ml CH4/g VS, followed by SF with 223.25 ± 10 N ml CH4 g-1 VS, substrate D also resulted in a methane potential of 144.69 ± 2 N ml CH4 g-1 VS. As pre-treatments, AL and AUAL both showed increase in methane yield (between 36.0% and 49.1%) and methane production rate. As post-treatments, AU, AL and AUAL showed distinctive results in methane production, with 33.8%, 99.8% and 128.8% increase, respectively. In comparison with pre-treatment, post-treatment showed a better performance in increasing methane production. The following feeding experiments performed in continuous stirred-tank reactors showed that AL treatment led to an average of 248% increase in methane yield., Sugarcane waste: towards a zero C emission in the Brazilian bioenergy sector

Resumo: O presente trabalho avaliou a influência de parâmetros físico-químicos na degradação de resíduos sólidos urbanos (RSU) de diferentes idades (fresco e 2 anos) bem como a sua relação com a geração de biogás. Os resíduos foram coletados no mesmo dia no aterro, preservados em sacos plásticos e em laboratório foram secados em estufa e moídos. Cada resíduo foi inoculado com lodo proveniente da unidade UASB de uma Estação de Tratamento de Efluentes (ETE) na proporção 50:1 (50 mL de lodo: 1 g de resíduo), todos em duplicata. Os parâmetros analisados no trabalho (pH, alcalinidade, umidade, NTK, DQO, DBO5 ST e SV) apresentaram valores semelhantes entre os resíduos indicando que, apesar da diferença de idade, ambos têm quantidades similares de material a ser biodegradado, contam com as mesmas condições necessárias para o processo de digestão anaeróbia e possuem capacidade de gerar quantidades semelhantes de biogás., This study evaluated the influence of physicochemical parameters in the degradation of municipal solid waste (MSW) of different ages (fresh and 2 years) as well as its relationship with the generation of biogas. Both wastes were collected at same day in landfill, preserved in plastic bags and, then, dried and ground in lab. Each waste was inoculated with sludge from the UASB reactor of a Wastewater Treatment Plant (WWTP) in the ratio 50: 1 (50 mL sludge: 1 g of residue), all in duplicate. The parameters analyzed (pH, alkalinity, moisture, NTK, COD, BOD5 ST and SV) were very similar between both residues, and indicated that despite the age difference, both have the similar amounts of material to be biodegraded, have the same conditions for the process of anaerobic digestion and the ability to generate similar amounts of biogas.

This study evaluated the potential of biogas generation of the fresh organic fraction of municipal solid wastes (OFMSW) inoculated with swine manure and cattle manure, based on the volatile solids content obtained from biochemical methane potential (BMP) tests. Several physico-chemical parameters (e.g. volatile solids, pH and chemical oxygen demand) were assessed in the laboratory before and after 50 days of incubation of several samples of OFMSW, swine manure and cattle manure, and mixtures thereof. During incubation, reductions in percentage of volatile solids were relatively low (from 5.5% to 11.4%), indicating the existence of substrates that can degrade after the 50-day digestion period. Among the physico-chemical parameters evaluated, pH was a limiting parameter for anaerobic digestion of OFMSW and manures. The mixture showing the best performance in terms of volume of biogas generated contained 1 gvs OFMSW: 1 gvs swine manure, which led to the production of 60.4 mL.gVS-1 or 22 mL.gOFMSW-1 biogas. The values of CH4 concentration increased throughout the incubation period, and the CH4 concentration value peaked at 80% for the mixture 1 gvs OFMSW:1 gvs swine manure. The results obtained indicate the OFMSW and manures can be effectively used for power generation.

Urban solid waste (MSW), when are discharged without proper treatment, causes severe damage to the environment, influencing the population's quality of life. For this reason, attention is currently paid to the proper handling of this waste. This paper studies the reduction of the organic fraction of solid waste (OFMSW), generated by a population group, taking as reference one of the Student Residences of the Universidad de Oriente. The generation of OFMSW in the residence is 0.06 kg/inhab-day, with a total solid content of 30.9 ± 5.3%, of which 81.7 ± 0.6% are volatile solids. The anaerobic digestion of OFMSW is evaluated through a two-stage treatment system. The first stage is performed in a drained-bed batch reactor, which allowed discontinuous and in-situ treatment of OFMSW, in anaerobic co-digestion with 25% of cow manure. In a second stage, the anaerobic treatment for the leachates generated in the batch reactor is evaluated, using a UASB reactor. In the batch reactor a removal of volatile solids of 44.1% was achieved, while in the UASB reactor 81.2% of COD was removed. As a result of the evaluation of the treatment system, total productivity of 5.37 L CH4 -kgSV-1·d-1 was achieved., resíduos sólidos urbanos (RSU), a ser descarregada sem tratamento adequado, causando graves danos ao meio ambiente influenciam a qualidade de vida da população, razão pela qual ele está atualmente fornecendo atenção diferenciada à descarga de resíduos urbanos. Neste trabalho é avaliada a fração orgânica desses resíduos (FORSU), tomando como referência o grupo populacional de uma Residência Estudantil da Universidade de Oriente. A geração de FORSU na residência é de 0,06 kg / hab / dia, com um teor total de sólidos de 30,9 ± 5,3%, dos quais 81,7 ± 0,6% são sólidos voláteis. execução de um reactor descontínuo de leito gotejar, o que permitiu um tratamento em lotes é avaliada e em FORSU situ em Co-digestão anaeróbia, com 25% de estrume de vaca numa primeira fase. Também avalia, em uma segunda etapa, o tratamento anaeróbio para os lixiviados que são gerados no reator em lotes, usando um reator UASB. No reator em lotes foi alcançada uma remoção de sólidos voláteis de 44,1%, enquanto que no reator UASB 81,2% de DQO foram removidos. Como resultado do sistema de tratamento avaliado, atingiu-se uma produtividade total de 5.37 LCH4 · kgSV-1 · d-1., Los residuos sólidos urbanos (RSU), al ser vertidos sin tratamiento adecuado, ocasionan daños severos al ambiente influyendo en la calidad de vida de la población, razón por la cual actualmente se le presta atención diferenciada al vertido de residuos urbanos. En este trabajo se evalúa la fracción orgánica de estos residuos (FORSU), tomando como referencia el grupo poblacional de una de las Residencias estudiantiles de la Universidad de Oriente. La generación de FORSU en la residencia es de 0,06 kg/hab/día, con un contenido de sólidos totales de 30,9 ± 5,3 % de los cuáles el 81,7 ± 0,6 % son sólidos volátiles. Se evalúa el funcionamiento de un reactor en lote de lecho escurrido, que permitió un tratamiento discontinuo e in situ de la FORSU, en codigestión anaerobia con un 25 % de estiércol vacuno en una primera etapa. También se evalúa, en una segunda etapa, el tratamiento anaerobio para los lixiviados que se generan en el reactor en lote, empleando un reactor UASB. En el reactor en lote se alcanzó una remoción de sólidos volátiles del 44,1 %, mientras que en el reactor UASB se removió un 81,2 % de DQO. Como resultado del sistema de tratamiento evaluado, se alcanzó una productividad total de 5,37 LCH4·kgSV-1·d-1.

BACKGROUND: The uncontrolled overproduction of fruit and vegetable waste causes serious environmental challenges such asemission of greenhouse gases. Anaerobic digestion (AD) is becoming a widely adopted technology for treatment of food wastewith the concomitant production of biogas. This study investigated the link between microbial community structure and biogasproduction when using cow dung and mixed fruit and vegetable waste (MFVW) as substrates.RESULTS: Semi-continuous stir tank reactors were used for AD of cow dung and MFVW over a period of 40 days. The highestaccumulative methane yield (112.9 L) was obtained from co- digestion, intermediate yield (59.5 L) was obtained from cow dungand lowest yield (6.1 L) from MFVW at the end of the digestion experiment. Polymerase chain reaction-denaturing gradientgel electrophoresis (PCR-DGGE) revealed higher bacterial and archaeal diversity indices in co-digestion in comparison tomono-digestion of cow dung and MFVW. High-throughput sequence analyses showed that operational taxonomic units (OTUs)belongingtothephylaBacteroidetes,followedbyFirmicutes,ActinobacteriaandProteobacteriaweredominantinalltreatments.CONCLUSION:Theresultsofthestudydemonstratedthattheenhancedmethaneproductioninco-digestioncouldbeattributedto the neutral pH and partial shift of archaea fromMethanosaetatoMethanosarcinarich communities

BACKGROUND: The uncontrolled overproduction of fruit and vegetable waste causes serious environmental challenges such asemission of greenhouse gases. Anaerobic digestion (AD) is becoming a widely adopted technology for treatment of food wastewith the concomitant production of biogas. This study investigated the link between microbial community structure and biogasproduction when using cow dung and mixed fruit and vegetable waste (MFVW) as substrates.RESULTS: Semi-continuous stir tank reactors were used for AD of cow dung and MFVW over a period of 40 days. The highestaccumulative methane yield (112.9 L) was obtained from co- digestion, intermediate yield (59.5 L) was obtained from cow dungand lowest yield (6.1 L) from MFVW at the end of the digestion experiment. Polymerase chain reaction-denaturing gradientgel electrophoresis (PCR-DGGE) revealed higher bacterial and archaeal diversity indices in co-digestion in comparison tomono-digestion of cow dung and MFVW. High-throughput sequence analyses showed that operational taxonomic units (OTUs)belongingtothephylaBacteroidetes,followedbyFirmicutes,ActinobacteriaandProteobacteriaweredominantinalltreatments.CONCLUSION:Theresultsofthestudydemonstratedthattheenhancedmethaneproductioninco-digestioncouldbeattributedto the neutral pH and partial shift of archaea fromMethanosaetatoMethanosarcinarich communities

Urban solid waste (MSW), when are discharged without proper treatment, causes severe damage to the environment, influencing the population's quality of life. For this reason, attention is currently paid to the proper handling of this waste. This paper studies the reduction of the organic fraction of solid waste (OFMSW), generated by a population group, taking as reference one of the Student Residences of the Universidad de Oriente. The generation of OFMSW in the residence is 0.06 kg/inhab-day, with a total solid content of 30.9 ± 5.3%, of which 81.7 ± 0.6% are volatile solids. The anaerobic digestion of OFMSW is evaluated through a two-stage treatment system. The first stage is performed in a drained-bed batch reactor, which allowed discontinuous and in-situ treatment of OFMSW, in anaerobic co-digestion with 25% of cow manure. In a second stage, the anaerobic treatment for the leachates generated in the batch reactor is evaluated, using a UASB reactor. In the batch reactor a removal of volatile solids of 44.1% was achieved, while in the UASB reactor 81.2% of COD was removed. As a result of the evaluation of the treatment system, total productivity of 5.37 L CH4 -kgSV-1·d-1 was achieved., resíduos sólidos urbanos (RSU), a ser descarregada sem tratamento adequado, causando graves danos ao meio ambiente influenciam a qualidade de vida da população, razão pela qual ele está atualmente fornecendo atenção diferenciada à descarga de resíduos urbanos. Neste trabalho é avaliada a fração orgânica desses resíduos (FORSU), tomando como referência o grupo populacional de uma Residência Estudantil da Universidade de Oriente. A geração de FORSU na residência é de 0,06 kg / hab / dia, com um teor total de sólidos de 30,9 ± 5,3%, dos quais 81,7 ± 0,6% são sólidos voláteis. execução de um reactor descontínuo de leito gotejar, o que permitiu um tratamento em lotes é avaliada e em FORSU situ em Co-digestão anaeróbia, com 25% de estrume de vaca numa primeira fase. Também avalia, em uma segunda etapa, o tratamento anaeróbio para os lixiviados que são gerados no reator em lotes, usando um reator UASB. No reator em lotes foi alcançada uma remoção de sólidos voláteis de 44,1%, enquanto que no reator UASB 81,2% de DQO foram removidos. Como resultado do sistema de tratamento avaliado, atingiu-se uma produtividade total de 5.37 LCH4 · kgSV-1 · d-1., Los residuos sólidos urbanos (RSU), al ser vertidos sin tratamiento adecuado, ocasionan daños severos al ambiente influyendo en la calidad de vida de la población, razón por la cual actualmente se le presta atención diferenciada al vertido de residuos urbanos. En este trabajo se evalúa la fracción orgánica de estos residuos (FORSU), tomando como referencia el grupo poblacional de una de las Residencias estudiantiles de la Universidad de Oriente. La generación de FORSU en la residencia es de 0,06 kg/hab/día, con un contenido de sólidos totales de 30,9 ± 5,3 % de los cuáles el 81,7 ± 0,6 % son sólidos volátiles. Se evalúa el funcionamiento de un reactor en lote de lecho escurrido, que permitió un tratamiento discontinuo e in situ de la FORSU, en codigestión anaerobia con un 25 % de estiércol vacuno en una primera etapa. También se evalúa, en una segunda etapa, el tratamiento anaerobio para los lixiviados que se generan en el reactor en lote, empleando un reactor UASB. En el reactor en lote se alcanzó una remoción de sólidos volátiles del 44,1 %, mientras que en el reactor UASB se removió un 81,2 % de DQO. Como resultado del sistema de tratamiento evaluado, se alcanzó una productividad total de 5,37 LCH4·kgSV-1·d-1.

Even though the Brazilian ethanol and sugar production system (based on sugarcane industry) have been providing large amounts of bioenergy, the extensive amounts of organic wastes generated cannot be ignored when it comes to sustainability. Using these biomasses to produce biomethane through anaerobic digestion has been proven as a promising way to tackle this issue. This study investigated the biomethane potential of the co-digestion of these biomasses: SF (sugarcane straw : filter cake = 8:2), SFV (sugarcane straw : filter cake : vinasse = 1:4:45), and D (digestate separated from AD of SFV). Three treatments autoclaving (AU), alkaline (AL) treatment using 6% (w/w) NaOH and the combination of these two (AUAL) were then conducted on SF and SFV as pre-treatments; on D as post- treatments. In the biomethane potential tests of untreated material, the highest methane yield was achieved by SFV with 275.28 ± 11 N ml CH4/g VS, followed by SF with 223.25 ± 10 N ml CH4 g-1 VS, substrate D also resulted in a methane potential of 144.69 ± 2 N ml CH4 g-1 VS. As pre-treatments, AL and AUAL both showed increase in methane yield (between 36.0% and 49.1%) and methane production rate. As post-treatments, AU, AL and AUAL showed distinctive results in methane production, with 33.8%, 99.8% and 128.8% increase, respectively. In comparison with pre-treatment, post-treatment showed a better performance in increasing methane production. The following feeding experiments performed in continuous stirred-tank reactors showed that AL treatment led to an average of 248% increase in methane yield., Sugarcane waste: towards a zero C emission in the Brazilian bioenergy sector

Increasing marine land-based recirculating aquaculture systems (RAS) and stricter environmental regulations, pose new challenges to the aquaculture industry on how to treat and dispose saline fish wastewater. The fish wastewater could be incorporated into biogas reactors, but currently, the effects of salinity on the biomethanation process are poorly known. This study aimed to assess the toxicity of fish wastewater with different salinities on the biomethanation process and to propose optimum co-digestion scenarios for maximal methane potential and safe use in biogas plants. Results showed that, depending on salinity and organic content, it is possible to efficiently co-digest from 3.22 to 61.85% fish wastewater (v/v, wastewater/manure) and improve the maximum methane production rate from 2.72 to 61.85%, respectively compared to cow manure mono-digestion. Additionally, salinity was identified as the main inhibitor of biomethanation process with a half-maximal inhibitory concentration (IC50) of 4.37 g L-1, while sulphate reduction was identified as a secondary inhibitor.

Urban solid waste (MSW), when are discharged without proper treatment, causes severe damage to the environment, influencing the population's quality of life. For this reason, attention is currently paid to the proper handling of this waste. This paper studies the reduction of the organic fraction of solid waste (OFMSW), generated by a population group, taking as reference one of the Student Residences of the Universidad de Oriente. The generation of OFMSW in the residence is 0.06 kg/inhab-day, with a total solid content of 30.9 ± 5.3%, of which 81.7 ± 0.6% are volatile solids. The anaerobic digestion of OFMSW is evaluated through a two-stage treatment system. The first stage is performed in a drained-bed batch reactor, which allowed discontinuous and in-situ treatment of OFMSW, in anaerobic co-digestion with 25% of cow manure. In a second stage, the anaerobic treatment for the leachates generated in the batch reactor is evaluated, using a UASB reactor. In the batch reactor a removal of volatile solids of 44.1% was achieved, while in the UASB reactor 81.2% of COD was removed. As a result of the evaluation of the treatment system, total productivity of 5.37 L CH4 -kgSV-1·d-1 was achieved., resíduos sólidos urbanos (RSU), a ser descarregada sem tratamento adequado, causando graves danos ao meio ambiente influenciam a qualidade de vida da população, razão pela qual ele está atualmente fornecendo atenção diferenciada à descarga de resíduos urbanos. Neste trabalho é avaliada a fração orgânica desses resíduos (FORSU), tomando como referência o grupo populacional de uma Residência Estudantil da Universidade de Oriente. A geração de FORSU na residência é de 0,06 kg / hab / dia, com um teor total de sólidos de 30,9 ± 5,3%, dos quais 81,7 ± 0,6% são sólidos voláteis. execução de um reactor descontínuo de leito gotejar, o que permitiu um tratamento em lotes é avaliada e em FORSU situ em Co-digestão anaeróbia, com 25% de estrume de vaca numa primeira fase. Também avalia, em uma segunda etapa, o tratamento anaeróbio para os lixiviados que são gerados no reator em lotes, usando um reator UASB. No reator em lotes foi alcançada uma remoção de sólidos voláteis de 44,1%, enquanto que no reator UASB 81,2% de DQO foram removidos. Como resultado do sistema de tratamento avaliado, atingiu-se uma produtividade total de 5.37 LCH4 · kgSV-1 · d-1., Los residuos sólidos urbanos (RSU), al ser vertidos sin tratamiento adecuado, ocasionan daños severos al ambiente influyendo en la calidad de vida de la población, razón por la cual actualmente se le presta atención diferenciada al vertido de residuos urbanos. En este trabajo se evalúa la fracción orgánica de estos residuos (FORSU), tomando como referencia el grupo poblacional de una de las Residencias estudiantiles de la Universidad de Oriente. La generación de FORSU en la residencia es de 0,06 kg/hab/día, con un contenido de sólidos totales de 30,9 ± 5,3 % de los cuáles el 81,7 ± 0,6 % son sólidos volátiles. Se evalúa el funcionamiento de un reactor en lote de lecho escurrido, que permitió un tratamiento discontinuo e in situ de la FORSU, en codigestión anaerobia con un 25 % de estiércol vacuno en una primera etapa. También se evalúa, en una segunda etapa, el tratamiento anaerobio para los lixiviados que se generan en el reactor en lote, empleando un reactor UASB. En el reactor en lote se alcanzó una remoción de sólidos volátiles del 44,1 %, mientras que en el reactor UASB se removió un 81,2 % de DQO. Como resultado del sistema de tratamiento evaluado, se alcanzó una productividad total de 5,37 LCH4·kgSV-1·d-1.

Australia is one of the major producers and exporter of agricultural products. Annually, Australian agriculture produces approximately 151 Tg CO2 equivalent emissions. The use of fossil fuels in crop cultivation, harvesting and transportation are considered as the primary source of these greenhouse gas (GHG) emissions. Moreover, agronomic management and crop residues left in the field also contribute to these GHG emissions. Alternative waste management practices include the use of crop residues and agro-wastes as feedstocks for bioenergy production. Anaerobic digestion is considered as sustainable environmental technology to convert industrial sugarcane residues to carbon dioxide (CO2) - neutral biogas. The biogas thus produced can be used to produce heat, electricity and upgrade to biomethane for vehicle use. The produced biomethane can replace the diesel consumption associated with GHG emission in cane transport. Sugarcane is one among the most cultivated crop in the world. Australia alone produced nearly 33.5 million tonnes of cane in 2018 (FAO 2018). These large production of sugarcane lead to an increase in crop residues and agro-wastes from the sugarcane industry. In this study, an investigation regarding the anaerobic co-digestion of crop residues and agro-wastes from sugarcane industry viz, sugarcane trash (SCT) or sugarcane bagasse (SCB) with chicken manure (CM) was investigated in a batch experiment at 37 °C. In spite of various researches conducted till date about co-digestion of lignocellulosic waste with manure, no research data was available regarding the effect of feed ratio on co-digestion of SCT/SCB with CM. This research gap was investigated in this study. In addition to this, steam explosion pre-treatment of SCT/SCB was included to investigate how the pre-treatment influence methane yield among different feed ratios of SCT/SCB with CM. At first, SCT and SCB were subjected to steam explosion pre-treatment (steam impregnation at 130 °C for 5 minutes, Thesis (Masters), Master of Philosophy (MPhil), School of Eng & Built Env, Science, Environment, Engineering and Technology, Full Text

The water, food and energy nexus is a vital subject to achieve sustainable development goals worldwide. Wastewater (WW) and food waste (FW) from municipal sources are the primary contributors of organic waste from cities. Along with the loss of these valuable natural resources, their treatment systems also consume a considerable amount of abiotic energy and resource input and make a perceptible contribution to global warming. Hence, the global paradigm has evolved from simple pollution mitigation to resource recovery systems. In this study, the prospects of FW co-disposal into the sewer system and treatment with municipal sewage were quantitatively investigated for Hong Kong's largest biological WW treatment plant (WWTP) by integrated plant-wide steady-state modelling (PWSSM) and lifecycle assessment (LCA) approaches. The investigation assessed the impacts on the design and operational capacity of the WWTP, effluent quality, sludge output, and its net energy and carbon footprint. The results revealed that even at a higher than normal FW to sewage ratio, the WWTP's organic load capacity and performance in terms of organics and nitrogen removal was not significantly degraded, in fact the denitrification efficiency was improved by the FW organics with low N/C ratio. The net energy balance was improved by 80-400%, the net carbon footprint was lowered by 37-63% (without biogenic emissions), while the sludge production was increased by ∼33%. The results are very sensitive and improved with greater influent FW concentration and solids capture in the primary settling unit of the WWTP. The differences in the results have to be seen in relation to uncontrolled methane emission and a faster filling rate if the FW were disposed to landfill. The study provides valuable insights and policy guidelines for the decision makers locally and a generic methodological template.

Resumo: O presente trabalho avaliou a influência de parâmetros físico-químicos na degradação de resíduos sólidos urbanos (RSU) de diferentes idades (fresco e 2 anos) bem como a sua relação com a geração de biogás. Os resíduos foram coletados no mesmo dia no aterro, preservados em sacos plásticos e em laboratório foram secados em estufa e moídos. Cada resíduo foi inoculado com lodo proveniente da unidade UASB de uma Estação de Tratamento de Efluentes (ETE) na proporção 50:1 (50 mL de lodo: 1 g de resíduo), todos em duplicata. Os parâmetros analisados no trabalho (pH, alcalinidade, umidade, NTK, DQO, DBO5 ST e SV) apresentaram valores semelhantes entre os resíduos indicando que, apesar da diferença de idade, ambos têm quantidades similares de material a ser biodegradado, contam com as mesmas condições necessárias para o processo de digestão anaeróbia e possuem capacidade de gerar quantidades semelhantes de biogás., This study evaluated the influence of physicochemical parameters in the degradation of municipal solid waste (MSW) of different ages (fresh and 2 years) as well as its relationship with the generation of biogas. Both wastes were collected at same day in landfill, preserved in plastic bags and, then, dried and ground in lab. Each waste was inoculated with sludge from the UASB reactor of a Wastewater Treatment Plant (WWTP) in the ratio 50: 1 (50 mL sludge: 1 g of residue), all in duplicate. The parameters analyzed (pH, alkalinity, moisture, NTK, COD, BOD5 ST and SV) were very similar between both residues, and indicated that despite the age difference, both have the similar amounts of material to be biodegraded, have the same conditions for the process of anaerobic digestion and the ability to generate similar amounts of biogas.

This study evaluated the potential of biogas generation of the fresh organic fraction of municipal solid wastes (OFMSW) inoculated with swine manure and cattle manure, based on the volatile solids content obtained from biochemical methane potential (BMP) tests. Several physico-chemical parameters (e.g. volatile solids, pH and chemical oxygen demand) were assessed in the laboratory before and after 50 days of incubation of several samples of OFMSW, swine manure and cattle manure, and mixtures thereof. During incubation, reductions in percentage of volatile solids were relatively low (from 5.5% to 11.4%), indicating the existence of substrates that can degrade after the 50-day digestion period. Among the physico-chemical parameters evaluated, pH was a limiting parameter for anaerobic digestion of OFMSW and manures. The mixture showing the best performance in terms of volume of biogas generated contained 1 gvs OFMSW: 1 gvs swine manure, which led to the production of 60.4 mL.gVS-1 or 22 mL.gOFMSW-1 biogas. The values of CH4 concentration increased throughout the incubation period, and the CH4 concentration value peaked at 80% for the mixture 1 gvs OFMSW:1 gvs swine manure. The results obtained indicate the OFMSW and manures can be effectively used for power generation.

The focus of the current study was on the recovery of carbon from municipal bio-waste streams. Firstly, the relationship between methanogenic pathways and the properties of anaerobic granules was studied using two pilot-scale upflow anaerobic sludge blanket (UASB) reactors with different granule size distribution. UASB1 granules were larger (3-4 mm) with multi-layered internal structure and the archaeal community was dominated by acetoclastic methanogens, while the UASB2 granules were smaller (1-2 mm) without a layered internal structure and the archaeal community was predominated by hydrogenotrophic methanogens. The acetoclastic methanogenic activities of UASB1 (250-437 mL CH4/g VS·d) than UASB2 (150-260 mL CH4/g VS·d), confirming that acetoclastic methanogenesis was more dominant in UASB1. Temperature increase from 20oC to 28oC did not change the microbial community but resulted in increased and stable biogas production for both reactors. There was an increase in chemical oxygen demand (COD) with hydraulic retention time due to increased contact time. The second part of the study focused on anaerobic co-digestion to produce volatile fatty acid (VFA) due to its higher value. The impact of substrate ratio of primary sludge (PS) and external organic waste (OW) and the robustness of the VFA system in the long term were assessed. Lab-scale batch study with different proportions of PS and OW; 0%, 25%, 50%, 75%, 100% of OW in terms of COD and scaled up in a semi-continuous pilot reactor with substrate ratio of 50% OW based on the results of the lab-scale study were performed. There was an increase in VFA production with an increase in OW proportion due to the availability of biodegradable organics. Acetic acid was the most dominant VFA in the batch reactors while in the semi-continuous experiment, caproic acid was dominated (50%). As carbon sources, the VFA-rich liquid attained the highest specific denitrification rate when compared with acetate and methanol., I kommunala avfallsströmmar finns det en stor potential för resursåtervinning på grund av det höga organiska innehållet vilket kan användas för biobaserade produkter. På grundval av detta så fokuserar denna studie på resursåtervinningen av kol från kommunala avfallsströmmar genom att undersöka nuvarande och nytillkomna tekniker för att få vattenreningssystem att också bli resursåtervinningssystem. Första delen av studien undersöker relationen mellan metanproduktion och karaktäriseringen av anaerobiska granuler med ändamålet att förbättra energiproduktionen genom direkt behandling av kommunalt avloppsvatten. För detta ändamål så användes två UASB (Upflow Anaerobic Sludge Blanket) pilotreaktorer. Reaktorerna kördes med olika stora granuler, olika temperaturinställningar och olika hydrauliska uppehållstider (HRTs). Storlek, mikrobiell struktur, intern mikrostruktur och specifik metanogenaktivitet av de anaerobiska granulerna analyserades. Granulerna i UASB1 var 3-4 mm stora med interna multilager av mikrostrukturer som bestod av acetoklastika-metanogen arkéer. Granulerna i UASB2 var 1- 2 mm stora utan interna multilager och bestod av hydrogenotrofa metanogener. Aktiviteten i granulerna i UASB1 var 250-437 mL CH4 /g VS·d och i UASB2 var det 150-260 mL CH4 /g VS·d, vilket bekräftar att de acetoklastisk-metanogesa var mer effektiva i UASB1 än de hydrogenotrofa i UASB2. Att öka temperaturen från 20 o C till 28 o C under försöket medförde ingen förändring av den mikrobiologiska strukturen, men gav en ökning i biogasproduktion i UASB1 och högre och stabilare biogasproduktionshastighet i UASB2. Ökningen av biogasproduktion berodde på en reduktion i metans löslighet i utflödet och stabilare metanogenes. Ökning i HRT resulterade i större reduktion av organiskt material mätt som kemisk syreförbrukning (COD) och större biogasproduktion på grund av längre kontakttid mellan substrat och mikroorganismer. Den andra delen av studien fokuserar på att utveckla ett tillvägagångssätt att, QC 2020-06-15

The focus of the current study was on the recovery of carbon from municipal bio-waste streams. Firstly, the relationship between methanogenic pathways and the properties of anaerobic granules was studied using two pilot-scale upflow anaerobic sludge blanket (UASB) reactors with different granule size distribution. UASB1 granules were larger (3-4 mm) with multi-layered internal structure and the archaeal community was dominated by acetoclastic methanogens, while the UASB2 granules were smaller (1-2 mm) without a layered internal structure and the archaeal community was predominated by hydrogenotrophic methanogens. The acetoclastic methanogenic activities of UASB1 (250-437 mL CH4/g VS·d) than UASB2 (150-260 mL CH4/g VS·d), confirming that acetoclastic methanogenesis was more dominant in UASB1. Temperature increase from 20oC to 28oC did not change the microbial community but resulted in increased and stable biogas production for both reactors. There was an increase in chemical oxygen demand (COD) with hydraulic retention time due to increased contact time. The second part of the study focused on anaerobic co-digestion to produce volatile fatty acid (VFA) due to its higher value. The impact of substrate ratio of primary sludge (PS) and external organic waste (OW) and the robustness of the VFA system in the long term were assessed. Lab-scale batch study with different proportions of PS and OW; 0%, 25%, 50%, 75%, 100% of OW in terms of COD and scaled up in a semi-continuous pilot reactor with substrate ratio of 50% OW based on the results of the lab-scale study were performed. There was an increase in VFA production with an increase in OW proportion due to the availability of biodegradable organics. Acetic acid was the most dominant VFA in the batch reactors while in the semi-continuous experiment, caproic acid was dominated (50%). As carbon sources, the VFA-rich liquid attained the highest specific denitrification rate when compared with acetate and methanol., I kommunala avfallsströmmar finns det en stor potential för resursåtervinning på grund av det höga organiska innehållet vilket kan användas för biobaserade produkter. På grundval av detta så fokuserar denna studie på resursåtervinningen av kol från kommunala avfallsströmmar genom att undersöka nuvarande och nytillkomna tekniker för att få vattenreningssystem att också bli resursåtervinningssystem. Första delen av studien undersöker relationen mellan metanproduktion och karaktäriseringen av anaerobiska granuler med ändamålet att förbättra energiproduktionen genom direkt behandling av kommunalt avloppsvatten. För detta ändamål så användes två UASB (Upflow Anaerobic Sludge Blanket) pilotreaktorer. Reaktorerna kördes med olika stora granuler, olika temperaturinställningar och olika hydrauliska uppehållstider (HRTs). Storlek, mikrobiell struktur, intern mikrostruktur och specifik metanogenaktivitet av de anaerobiska granulerna analyserades. Granulerna i UASB1 var 3-4 mm stora med interna multilager av mikrostrukturer som bestod av acetoklastika-metanogen arkéer. Granulerna i UASB2 var 1- 2 mm stora utan interna multilager och bestod av hydrogenotrofa metanogener. Aktiviteten i granulerna i UASB1 var 250-437 mL CH4 /g VS·d och i UASB2 var det 150-260 mL CH4 /g VS·d, vilket bekräftar att de acetoklastisk-metanogesa var mer effektiva i UASB1 än de hydrogenotrofa i UASB2. Att öka temperaturen från 20 o C till 28 o C under försöket medförde ingen förändring av den mikrobiologiska strukturen, men gav en ökning i biogasproduktion i UASB1 och högre och stabilare biogasproduktionshastighet i UASB2. Ökningen av biogasproduktion berodde på en reduktion i metans löslighet i utflödet och stabilare metanogenes. Ökning i HRT resulterade i större reduktion av organiskt material mätt som kemisk syreförbrukning (COD) och större biogasproduktion på grund av längre kontakttid mellan substrat och mikroorganismer. Den andra delen av studien fokuserar på att utveckla ett tillvägagångssätt att, QC 2020-06-15

The focus of the current study was on the recovery of carbon from municipal bio-waste streams. Firstly, the relationship between methanogenic pathways and the properties of anaerobic granules was studied using two pilot-scale upflow anaerobic sludge blanket (UASB) reactors with different granule size distribution. UASB1 granules were larger (3-4 mm) with multi-layered internal structure and the archaeal community was dominated by acetoclastic methanogens, while the UASB2 granules were smaller (1-2 mm) without a layered internal structure and the archaeal community was predominated by hydrogenotrophic methanogens. The acetoclastic methanogenic activities of UASB1 (250-437 mL CH4/g VS·d) than UASB2 (150-260 mL CH4/g VS·d), confirming that acetoclastic methanogenesis was more dominant in UASB1. Temperature increase from 20oC to 28oC did not change the microbial community but resulted in increased and stable biogas production for both reactors. There was an increase in chemical oxygen demand (COD) with hydraulic retention time due to increased contact time. The second part of the study focused on anaerobic co-digestion to produce volatile fatty acid (VFA) due to its higher value. The impact of substrate ratio of primary sludge (PS) and external organic waste (OW) and the robustness of the VFA system in the long term were assessed. Lab-scale batch study with different proportions of PS and OW; 0%, 25%, 50%, 75%, 100% of OW in terms of COD and scaled up in a semi-continuous pilot reactor with substrate ratio of 50% OW based on the results of the lab-scale study were performed. There was an increase in VFA production with an increase in OW proportion due to the availability of biodegradable organics. Acetic acid was the most dominant VFA in the batch reactors while in the semi-continuous experiment, caproic acid was dominated (50%). As carbon sources, the VFA-rich liquid attained the highest specific denitrification rate when compared with acetate and methanol., I kommunala avfallsströmmar finns det en stor potential för resursåtervinning på grund av det höga organiska innehållet vilket kan användas för biobaserade produkter. På grundval av detta så fokuserar denna studie på resursåtervinningen av kol från kommunala avfallsströmmar genom att undersöka nuvarande och nytillkomna tekniker för att få vattenreningssystem att också bli resursåtervinningssystem. Första delen av studien undersöker relationen mellan metanproduktion och karaktäriseringen av anaerobiska granuler med ändamålet att förbättra energiproduktionen genom direkt behandling av kommunalt avloppsvatten. För detta ändamål så användes två UASB (Upflow Anaerobic Sludge Blanket) pilotreaktorer. Reaktorerna kördes med olika stora granuler, olika temperaturinställningar och olika hydrauliska uppehållstider (HRTs). Storlek, mikrobiell struktur, intern mikrostruktur och specifik metanogenaktivitet av de anaerobiska granulerna analyserades. Granulerna i UASB1 var 3-4 mm stora med interna multilager av mikrostrukturer som bestod av acetoklastika-metanogen arkéer. Granulerna i UASB2 var 1- 2 mm stora utan interna multilager och bestod av hydrogenotrofa metanogener. Aktiviteten i granulerna i UASB1 var 250-437 mL CH4 /g VS·d och i UASB2 var det 150-260 mL CH4 /g VS·d, vilket bekräftar att de acetoklastisk-metanogesa var mer effektiva i UASB1 än de hydrogenotrofa i UASB2. Att öka temperaturen från 20 o C till 28 o C under försöket medförde ingen förändring av den mikrobiologiska strukturen, men gav en ökning i biogasproduktion i UASB1 och högre och stabilare biogasproduktionshastighet i UASB2. Ökningen av biogasproduktion berodde på en reduktion i metans löslighet i utflödet och stabilare metanogenes. Ökning i HRT resulterade i större reduktion av organiskt material mätt som kemisk syreförbrukning (COD) och större biogasproduktion på grund av längre kontakttid mellan substrat och mikroorganismer. Den andra delen av studien fokuserar på att utveckla ett tillvägagångssätt att, QC 2020-06-15

The focus of the current study was on the recovery of carbon from municipal bio-waste streams. Firstly, the relationship between methanogenic pathways and the properties of anaerobic granules was studied using two pilot-scale upflow anaerobic sludge blanket (UASB) reactors with different granule size distribution. UASB1 granules were larger (3-4 mm) with multi-layered internal structure and the archaeal community was dominated by acetoclastic methanogens, while the UASB2 granules were smaller (1-2 mm) without a layered internal structure and the archaeal community was predominated by hydrogenotrophic methanogens. The acetoclastic methanogenic activities of UASB1 (250-437 mL CH4/g VS·d) than UASB2 (150-260 mL CH4/g VS·d), confirming that acetoclastic methanogenesis was more dominant in UASB1. Temperature increase from 20oC to 28oC did not change the microbial community but resulted in increased and stable biogas production for both reactors. There was an increase in chemical oxygen demand (COD) with hydraulic retention time due to increased contact time. The second part of the study focused on anaerobic co-digestion to produce volatile fatty acid (VFA) due to its higher value. The impact of substrate ratio of primary sludge (PS) and external organic waste (OW) and the robustness of the VFA system in the long term were assessed. Lab-scale batch study with different proportions of PS and OW; 0%, 25%, 50%, 75%, 100% of OW in terms of COD and scaled up in a semi-continuous pilot reactor with substrate ratio of 50% OW based on the results of the lab-scale study were performed. There was an increase in VFA production with an increase in OW proportion due to the availability of biodegradable organics. Acetic acid was the most dominant VFA in the batch reactors while in the semi-continuous experiment, caproic acid was dominated (50%). As carbon sources, the VFA-rich liquid attained the highest specific denitrification rate when compared with acetate and methanol., I kommunala avfallsströmmar finns det en stor potential för resursåtervinning på grund av det höga organiska innehållet vilket kan användas för biobaserade produkter. På grundval av detta så fokuserar denna studie på resursåtervinningen av kol från kommunala avfallsströmmar genom att undersöka nuvarande och nytillkomna tekniker för att få vattenreningssystem att också bli resursåtervinningssystem. Första delen av studien undersöker relationen mellan metanproduktion och karaktäriseringen av anaerobiska granuler med ändamålet att förbättra energiproduktionen genom direkt behandling av kommunalt avloppsvatten. För detta ändamål så användes två UASB (Upflow Anaerobic Sludge Blanket) pilotreaktorer. Reaktorerna kördes med olika stora granuler, olika temperaturinställningar och olika hydrauliska uppehållstider (HRTs). Storlek, mikrobiell struktur, intern mikrostruktur och specifik metanogenaktivitet av de anaerobiska granulerna analyserades. Granulerna i UASB1 var 3-4 mm stora med interna multilager av mikrostrukturer som bestod av acetoklastika-metanogen arkéer. Granulerna i UASB2 var 1- 2 mm stora utan interna multilager och bestod av hydrogenotrofa metanogener. Aktiviteten i granulerna i UASB1 var 250-437 mL CH4 /g VS·d och i UASB2 var det 150-260 mL CH4 /g VS·d, vilket bekräftar att de acetoklastisk-metanogesa var mer effektiva i UASB1 än de hydrogenotrofa i UASB2. Att öka temperaturen från 20 o C till 28 o C under försöket medförde ingen förändring av den mikrobiologiska strukturen, men gav en ökning i biogasproduktion i UASB1 och högre och stabilare biogasproduktionshastighet i UASB2. Ökningen av biogasproduktion berodde på en reduktion i metans löslighet i utflödet och stabilare metanogenes. Ökning i HRT resulterade i större reduktion av organiskt material mätt som kemisk syreförbrukning (COD) och större biogasproduktion på grund av längre kontakttid mellan substrat och mikroorganismer. Den andra delen av studien fokuserar på att utveckla ett tillvägagångssätt att, QC 2020-06-15

El uso de energías renovables es una idea que se está empezando a implementar en Colombia; es importante la ejecución de nuevas tecnologías en el país para así potencializar el desarrollo socio-económico de Colombia. La investigación parte del estudio de cantidades de biomasa producida en las actividades agrarias y pecuarias del departamento de Antioquia, identificando así lo sectores con mayor generación de residuos. Luego se procede a asignar las características fisicoquímicas de cada tipo de residuo de las actividades registradas y de estas mismas identificar los potenciales de biogás. A partir de lo anterior, se analizan las diferentes posibilidades de codigestión teniendo en cuenta el lugar de desarrollo de las actividades agrarias, para así definir la ubicación y dimensionamiento necesario para las propuestas. Es así como se plantean cuatro propuestas de codigestión anaerobia para la producción de energía a partir de los residuos producidos por la actividad agrícola y pecuaria en Colombia. Los volúmenes necesarios para las propuestas oscilan entre los 8.500 m3 y los 23.000 m3. De las cuatro propuestas, la propuesta número cuatro consiste en la codigestión de los residuos de los cultivos de arroz y de la actividad avícola que es la que más produce energía al año, generando 16.023.379 kWh/año.

In diversifying the economies of most oil producing countries especially in regions with arable lands, Agriculture becomes the next choice aside mineral deposits. This has led to a search for an alternative to inorganic fertilizers, the alternatives are the biofertilizers. The paper discussed the classification of the anaerobic co-digestion process based on the application of inoculants to the biodigester feedstock to speed up the digestion process and the absence of inoculants. Biodigester feedstock also looked at the various mechanisms in the digestion process which includes hydrolysis, acidogenesis, acetogenesis, and methanogenesis, the pathways were illustrated with chemical equations and various microorganisms that take part in the anaerobic process were mentioned and tabulated. The types of biofertilizers, merits, and demerits, the difference between biofertilizers and organic fertilizers were comprehensively discussed. Current trends on the application of the co-digestion technique to improve the yield, nutrient, and safety of biofertilizers and also the recent progression on the technique were mentioned.

In diversifying the economies of most oil producing countries especially in regions with arable lands, Agriculture becomes the next choice aside mineral deposits. This has led to a search for an alternative to inorganic fertilizers, the alternatives are the biofertilizers. The paper discussed the classification of the anaerobic co-digestion process based on the application of inoculants to the biodigester feedstock to speed up the digestion process and the absence of inoculants. Biodigester feedstock also looked at the various mechanisms in the digestion process which includes hydrolysis, acidogenesis, acetogenesis, and methanogenesis, the pathways were illustrated with chemical equations and various microorganisms that take part in the anaerobic process were mentioned and tabulated. The types of biofertilizers, merits, and demerits, the difference between biofertilizers and organic fertilizers were comprehensively discussed. Current trends on the application of the co-digestion technique to improve the yield, nutrient, and safety of biofertilizers and also the recent progression on the technique were mentioned.

This work proposes a new treatment approach involving both food waste disposal and sewerage treatment called MOWFAST i.e. Municipal Organic Waste management by combined Food waste disposal and Sewerage Treatment. MOWFAST involves mixing of food waste directly with raw sewage instead of separate addition to sludge and their combined anaerobic digestion (AD). Compared to conventional sludge digestion, MOWFAST exhibited better digestion capability and allowed a greater degradation of organic material along with higher production of methanogenic-favourable products from the beginning of digestion. This resulted in producing higher specific methane yields (7.86 LCH4/kg VSadded versus 0.95 LCH4/kg VSadded) and 1.4-fold higher cumulative methane yield over sludge AD. Furthermore, compared with conventional food waste-sludge co-digestion, MOWFAST gave higher solubilization of organic material (0.82 g sCOD/g VSadded versus 0.23 g sCOD/g VSadded) and specific methane yields (7.86 LCH4/kg VSadded versus 3.2 LCH4/kg VSadded). This proves its feasibility for digestion and methane generation potential.

This work proposes a new treatment approach involving both food waste disposal and sewerage treatment called MOWFAST i.e. Municipal Organic Waste management by combined Food waste disposal and Sewerage Treatment. MOWFAST involves mixing of food waste directly with raw sewage instead of separate addition to sludge and their combined anaerobic digestion (AD). Compared to conventional sludge digestion, MOWFAST exhibited better digestion capability and allowed a greater degradation of organic material along with higher production of methanogenic-favourable products from the beginning of digestion. This resulted in producing higher specific methane yields (7.86 LCH4/kg VSadded versus 0.95 LCH4/kg VSadded) and 1.4-fold higher cumulative methane yield over sludge AD. Furthermore, compared with conventional food waste-sludge co-digestion, MOWFAST gave higher solubilization of organic material (0.82 g sCOD/g VSadded versus 0.23 g sCOD/g VSadded) and specific methane yields (7.86 LCH4/kg VSadded versus 3.2 LCH4/kg VSadded). This proves its feasibility for digestion and methane generation potential.

Biochemical energy recovery using digestion and co-digestion of faecal matter collected from urine diverting dehydrating toilet faeces (UDDT-F) and mixed organic market waste (OMW) was studied under laboratory-and pilot-scale conditions. Laboratory-scale biochemical methane potential (BMP) tests showed an increase in methane production with an increase in OMW fraction in the feed substrate. In subsequent pilot-scale experiments, one-stage and two-stage plug flow digester were researched, applying UDDT-F:OMW ratios of 4:1 and 1:0, at about 10 and 12% total solids (TS) slurry concentrations. Comparable methane production was observed in one-stage (Ro-4:1,12%) (314 ± 15 mL CH4/g VS added) and two-stage (Ram-4:1,12%) (325 ± 12 mL CH4 /g VS added) digesters, when applying 12% TS slurry concentration. However, biogas production in Ram-4:1,12% digester (571 ± 25 mL CH4/g VS added) was about 12% higher than in Ro-4:1,12%, significantly more than the slight difference in methane production, i.e. 3–4%. The former was attributed to enhanced waste solubilisation and increased CO2 dissolution, resulting from mixing the bicarbonate-rich methanogenic effluent for neutralisation purposes with the low pH (4.9) influent acquired from the pre-acidification stage. Moreover, higher process stability was observed in the first parts of the plug flow two-stage digester, characterised by lower VFA concentrations., Sanitary Engineering