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The aim of this study was to assess the environmental impacts of up-flow anaerobic sludge blanket (UASB) reactors coupled with high rate algal ponds (HRAPs) for wastewater treatment and bioenergy recovery using the Life Cycle Assessment (LCA) methodology. This solution was compared with the UASB reactor coupled with other consolidated technologies in rural areas of Brazil, such as trickling filters, polishing ponds and constructed wetlands. To this end, full-scale systems were designed based on experimental data obtained from pilot/demonstrative scale systems. The functional unit was 1 m3 of water. System boundaries comprised input and output flows of material and energy resources for system construction and operation. The LCA was performed with the software SimaPro®, using the ReCiPe midpoint method. The results showed that the HRAPs scenario was the most environmentally friendly alternative in 4 out of 8 impact categories (i.e. Global warming, Stratospheric Ozone Depletion, Terrestrial Ecotoxicity and Fossil resource scarcity). This was associated with the increase in biogas production by the co-digestion of microalgae and raw wastewater, leading to higher electricity and heat recovery. From an economic point of view, despite the HRAPs showed a higher capital cost, the operation and maintenance costs were completely offset by the revenue obtained from the electricity generated. Overall, the UASB reactor coupled with HRAPS showed to be a feasible nature-based solution to be used in small communities in Brazil, especially when microalgae biomass is valorised and used to increase biogas productivity., The research was funded by the National Council for Scientific and Technological Development from Brazilian Ministry of Education – CNPq, the Reference Centre of Sustainable Sewage Treatment Plants - CR ETES, the Institute of Sustainable Sewage Treatment Plants - INCT ETEs, the Coordination for the Improvement of Higher Education Personnel – CAPES, the Foundation for Research of the State of Minas Gerais – FAPEMIG, and the CNPQ and to National Health Foundation – FUNASA from Brasil. Lucas Vassalle is grateful to the CNPQ (scholarship 204026/2018-0). Ivet Ferrer and Marianna Garfí are grateful to the Government of Catalonia (Consolidated Research Group 2017 SGR 1029), and Marianna Garfí to the Spanish Ministry of Economy and Competitiveness (RYC-2016 20059)., Peer Reviewed, Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant, Objectius de Desenvolupament Sostenible::6 - Aigua Neta i Sanejament, Postprint (author's final draft)

Residence time distribution (RTD) curves play an essential role in the hydraulic characterization of reactors. Current approaches for obtaining RTD curves in laboratory-scale reactors are time-consuming and subject to large errors. Thus, automated systems to obtain RTD curves in laboratory-scale reactors are of great interest for reducing experimental errors due to human interaction, minimizing experimentation costs, and continuously obtaining experimental data. An automated system for obtaining RTD curves in laboratory-scale reactors was designed, built, and tested in this work. During the tests conducted in a cylindrical upflow anaerobic sludge blanket (UASB) reactor, the system worked properly using the stimulus–response pulse technique with sodium chloride as a tracer. Four main factors were found to affect the representativeness of the RTD curves: flow stabilization time, test water conductivity, temperature, and surface tension. A discussion on these factors and the corresponding solutions is presented. The RTD curves of the UASB reactor are left-skewed with a typical tank reactor’s flow shape with channeling and dead zones. A transitory flow behavior was evidenced in the reactor, which indicates the influence of internal turbulent flow structures. The system proposed herein is expected to help study the hydraulics of reactors using laboratory-scale models more efficiently

BACKGROUND The aim of the present research was to provide a strategy for the start‐up of upflow anaerobic sludge blanket (UASB) reactors treating sugar cane vinasse, with emphasis on the relevant sulfur compounds along the reactor height. To this end, a laboratory‐scale UASB reactor was started up and its performance under the applied conditions was studied. RESULTS Biomass was able to assimilate organic loading rates from 3 to 10 kg chemical oxygen demand (COD) mR−3 d−1, reducing VFAs accumulation, while increasing biogas production rate (BPR) from 0.92 to 4.12 m3 mR−3 d−1. The COD and sulfate (SO42−) were mainly removed in the reactor bed, showing homogenous distribution in the blanket and settler zones. However, from bottom to top of the reactor, a slight decrease of total and free sulfide concentrations was observed, indicating that the sludge bed in the UASB reactor was exposed to H2S concentrations higher than those measured in the reactor effluent. CONCLUSIONS During 54 days, the development of macroscopic granules, the COD removal efficiency, the BPR and the CH4 content proved good indicators to monitor the start‐up period. Further research will be needed for strategy validation in pilot and full‐scale UASB reactors treating vinasse., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Sanitary Engineering

BACKGROUND The aim of the present research was to provide a strategy for the start‐up of upflow anaerobic sludge blanket (UASB) reactors treating sugar cane vinasse, with emphasis on the relevant sulfur compounds along the reactor height. To this end, a laboratory‐scale UASB reactor was started up and its performance under the applied conditions was studied. RESULTS Biomass was able to assimilate organic loading rates from 3 to 10 kg chemical oxygen demand (COD) mR−3 d−1, reducing VFAs accumulation, while increasing biogas production rate (BPR) from 0.92 to 4.12 m3 mR−3 d−1. The COD and sulfate (SO42−) were mainly removed in the reactor bed, showing homogenous distribution in the blanket and settler zones. However, from bottom to top of the reactor, a slight decrease of total and free sulfide concentrations was observed, indicating that the sludge bed in the UASB reactor was exposed to H2S concentrations higher than those measured in the reactor effluent. CONCLUSIONS During 54 days, the development of macroscopic granules, the COD removal efficiency, the BPR and the CH4 content proved good indicators to monitor the start‐up period. Further research will be needed for strategy validation in pilot and full‐scale UASB reactors treating vinasse., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Sanitary Engineering

Upflow anaerobic sludge blanket (UASB) reactors are widely used to treat domestic sewage and frequently require post-treatment. Little is known about the use of high rate algal ponds (HRAP) for post-treating UASB reactors’ effluent. This study aimed to evaluate a UASB reactor followed by a HRAP in terms of sewage treatment efficiency and biogas production, during one year at demonstration–scale. The UASB reactor co-treated raw sewage and the harvested microalgal biomass from the HRAP, which was recirculated to the reactor. An identical UASB reactor, treating only raw sewage, was used as control. The results showed an overall removal of 65% COD and 61% N-NH4 in the system. Furthermore, methane yield was increased by 25% after anaerobic co-digestion with microalgae, from 156 to 211 NL CH4 kg-1 VS. An energy assessment was performed and showed a positive energy balance, with a net ratio of 2.11 to the annual average., Peer Reviewed, Postprint (author's final draft)

The implementation of new processes for the use of residual biomass is one of the intrinsic goals in the goals established within the objectives of sustainable development to contribute to environmental energy security. This article deals with the production of biogas by co-digestion of bovine waste and bovine manure in two UASB reactors with the same dimensions, with thermal isolation system and without external heating and an average temperature of 16°C, differentiated only because one of them incorporated a manual agitation system. The mixture of pruning residue and cow manure was made with a 1: 2 ratios, a pH of 6.24 and 7.3 (respectively) and a humidity greater than 60%. During the process, it was possible to observe the acidification of the reactor without agitation, which inhibited the production of biogas, while in the system with agitation until day 90, produced 11 L of biogas with a methane composition of 21.11%, which showed the favorable effect of agitation on the anaerobic digestion process., La implementación de nuevos procesos para el aprovechamiento de la biomasa residual, es una de las prioridades intrínsecas en las metas establecidas dentro de los objetivos de desarrollo sostenible para contribuir a la seguridad energética ambiental. El presente artículo aborda la producción de biogás mediante la codigestión de residuo de poda y estiércol bovino en dos reactores UASB con las mismas dimensiones con sistema de aislamiento térmico y sin calentamiento, operando a una temperatura media de 16 °C, diferenciados en la incorporación de un sistema de agitación manual. La relación de las materias primas fueron 1:2 a pH de 6,24 y 7,3, respectivamente con humedad superior al 60%. Se observó la acidificación del sistema sin agitación, lo que inhibió la producción de biogás, mientras que en el sistema con agitación hasta el día 90 produjo 11 L de biogás con 21,11% de metano, lo que mostró el efecto favorable de la agitación en el proceso de digestión anaerobia.

The implementation of new processes for the use of residual biomass is one of the intrinsic goals in the goals established within the objectives of sustainable development to contribute to environmental energy security. This article deals with the production of biogas by co-digestion of bovine waste and bovine manure in two UASB reactors with the same dimensions, with thermal isolation system and without external heating and an average temperature of 16°C, differentiated only because one of them incorporated a manual agitation system. The mixture of pruning residue and cow manure was made with a 1: 2 ratios, a pH of 6.24 and 7.3 (respectively) and a humidity greater than 60%. During the process, it was possible to observe the acidification of the reactor without agitation, which inhibited the production of biogas, while in the system with agitation until day 90, produced 11 L of biogas with a methane composition of 21.11%, which showed the favorable effect of agitation on the anaerobic digestion process., La implementación de nuevos procesos para el aprovechamiento de la biomasa residual, es una de las prioridades intrínsecas en las metas establecidas dentro de los objetivos de desarrollo sostenible para contribuir a la seguridad energética ambiental. El presente artículo aborda la producción de biogás mediante la codigestión de residuo de poda y estiércol bovino en dos reactores UASB con las mismas dimensiones con sistema de aislamiento térmico y sin calentamiento, operando a una temperatura media de 16 °C, diferenciados en la incorporación de un sistema de agitación manual. La relación de las materias primas fueron 1:2 a pH de 6,24 y 7,3, respectivamente con humedad superior al 60%. Se observó la acidificación del sistema sin agitación, lo que inhibió la producción de biogás, mientras que en el sistema con agitación hasta el día 90 produjo 11 L de biogás con 21,11% de metano, lo que mostró el efecto favorable de la agitación en el proceso de digestión anaerobia.

The implementation of new processes for the use of residual biomass is one of the intrinsic goals in the goals established within the objectives of sustainable development to contribute to environmental energy security. This article deals with the production of biogas by co-digestion of bovine waste and bovine manure in two UASB reactors with the same dimensions, with thermal isolation system and without external heating and an average temperature of 16°C, differentiated only because one of them incorporated a manual agitation system. The mixture of pruning residue and cow manure was made with a 1: 2 ratios, a pH of 6.24 and 7.3 (respectively) and a humidity greater than 60%. During the process, it was possible to observe the acidification of the reactor without agitation, which inhibited the production of biogas, while in the system with agitation until day 90, produced 11 L of biogas with a methane composition of 21.11%, which showed the favorable effect of agitation on the anaerobic digestion process., La implementación de nuevos procesos para el aprovechamiento de la biomasa residual, es una de las prioridades intrínsecas en las metas establecidas dentro de los objetivos de desarrollo sostenible para contribuir a la seguridad energética ambiental. El presente artículo aborda la producción de biogás mediante la codigestión de residuo de poda y estiércol bovino en dos reactores UASB con las mismas dimensiones con sistema de aislamiento térmico y sin calentamiento, operando a una temperatura media de 16 °C, diferenciados en la incorporación de un sistema de agitación manual. La relación de las materias primas fueron 1:2 a pH de 6,24 y 7,3, respectivamente con humedad superior al 60%. Se observó la acidificación del sistema sin agitación, lo que inhibió la producción de biogás, mientras que en el sistema con agitación hasta el día 90 produjo 11 L de biogás con 21,11% de metano, lo que mostró el efecto favorable de la agitación en el proceso de digestión anaerobia.

The test of specific methanogenic activity (SMA) allows knowledge about the potential of anaerobic sludge in the digestion of organic material, however, it does not yet have a practical protocol for its most widespread development in the Treatment Stations. The present work intends to make a comparison between two SMA methods, one simplified and one automated. In both methods there was inoculation of anaerobic reactor sludge, dilution with nutrient solution and addition of substrate (sodium acetate), in adequate concentrations. For the simplified method, antibiotic flasks were used with manual measurement of biogas production using a glass syringe and methane analysis via chromatography. In the automated method, the AMPTS (Automatic Methane Potential Test System) was used, which provided the results through interface with specific software. The results obtained with the simplified method were more coherent than expected (values around the range of 0.2 to 0.3 gDQOCH4/gSV.d), reliable and of lower cost, considering all the material resources involved, when compared with the obtained with automated method (values around 0.1 gDQOCH4/gSV.d). In addition, it has been found that new practices can be implemented., O teste da atividade metanogênica específica (AME) permite conhecimento sobre o potencial de lodos anaeróbios em digestão de material orgânico, no entanto, ainda não possui protocolo prático para o seu desenvolvimento mais disseminado nas Estações de Tratamento. O presente trabalho avaliou dois métodos de AME, um simplificado e outro automatizado. Em ambos métodos houve inoculação de lodo de reator anaeróbio, diluição com solução nutritiva e adição de substrato (acetato de sódio), em concentrações adequadas. Para o método simplificado foram utilizados frascos de antibiótico com medição manual da produção de biogás, por meio de seringa esmerilhada, e análise de metano via cromatografia. No método automatizado foi utilizado o equipamento AMPTS (Automatic Methane Potential Test System), o qual fornecia os resultados por meio de interface com software específico. Os resultados obtidos com o método simplificado foram mais coerentes ao esperado (valores em torno da faixa de 0,2 a 0,3 gDQOCH4/gSV.d), confiáveis e de custo inferior, considerando todos os recursos materiais envolvidos, quando comparados com os obtidos com método automatizado (valores em torno de 0,1 gDQOCH4/gSV.d). Além disso, verificou-se que novas praticidades podem ser implementadas.

The start-up process of a pilot-scale upflow anaerobic sludge blanket (UASB) reactor was evaluated for the treatment of intensive pig farming wastewater. The reactor was inoculated with a mix of granular and flocculent sludge, from two UASB reactors treating brewery wastewater, and swine wastewater sediments. In the start-up process the organic loading rate applied to the system was increased stepwise by decreasing the dilution ratio of the swine wastewater in a three-stage process. By the final stage of the start-up process no dilution was applied to the wastewater. The average chemical oxygen demand (COD) removal efficiency in the reactor at the final stage of the start-up was 83,7% while working with an average organic loading rate of 2,4 kg COD.m-3 .d-1 . At the final stage of the start up the average total suspended solids concentration in the reactor’s influent reached 2786 mg SST.L-1 and did not affect the COD removal efficiencies negatively., Se evaluó la puesta en marcha de un reactor de flujo ascendente en manto de lodos (UASB) a escala piloto, aplicado al tratamiento de aguas residuales de la crianza intensiva de cerdos. El reactor fue inoculado con una mezcla de lodos granulares y floculentos, procedentes de dos reactores UASB usados en el tratamiento de efluentes de cervecería, junto con sedimentos de efluentes porcinos. Durante la puesta en marcha, la velocidad de carga orgánica aplicada al sistema se incrementó progresivamente en tres etapas a través de la disminución del porcentaje de dilución del agua residual. En la última etapa se usó agua residual sin dilución. Durante la etapa final de arranque, trabajando con una velocidad de carga orgánica promedio de 2,4 kgDQO.m3.d-1, el reactor presentó una eficiencia de remoción promedio de DQO de 83,7%. Durante esta etapa, la concentración promedio de sólidos suspendidos totales (SST) de 2786 mg.L-1 en el afluente del reactor no afectó la eficiencia de remoción de DQO.

The start-up process of a pilot-scale upflow anaerobic sludge blanket (UASB) reactor was evaluated for the treatment of intensive pig farming wastewater. The reactor was inoculated with a mix of granular and flocculent sludge, from two UASB reactors treating brewery wastewater, and swine wastewater sediments. In the start-up process the organic loading rate applied to the system was increased stepwise by decreasing the dilution ratio of the swine wastewater in a three-stage process. By the final stage of the start-up process no dilution was applied to the wastewater. The average chemical oxygen demand (COD) removal efficiency in the reactor at the final stage of the start-up was 83,7% while working with an average organic loading rate of 2,4 kg COD.m-3 .d-1 . At the final stage of the start up the average total suspended solids concentration in the reactor’s influent reached 2786 mg SST.L-1 and did not affect the COD removal efficiencies negatively., Se evaluó la puesta en marcha de un reactor de flujo ascendente en manto de lodos (UASB) a escala piloto, aplicado al tratamiento de aguas residuales de la crianza intensiva de cerdos. El reactor fue inoculado con una mezcla de lodos granulares y floculentos, procedentes de dos reactores UASB usados en el tratamiento de efluentes de cervecería, junto con sedimentos de efluentes porcinos. Durante la puesta en marcha, la velocidad de carga orgánica aplicada al sistema se incrementó progresivamente en tres etapas a través de la disminución del porcentaje de dilución del agua residual. En la última etapa se usó agua residual sin dilución. Durante la etapa final de arranque, trabajando con una velocidad de carga orgánica promedio de 2,4 kgDQO.m3.d-1, el reactor presentó una eficiencia de remoción promedio de DQO de 83,7%. Durante esta etapa, la concentración promedio de sólidos suspendidos totales (SST) de 2786 mg.L-1 en el afluente del reactor no afectó la eficiencia de remoción de DQO.

The test of specific methanogenic activity (SMA) allows knowledge about the potential of anaerobic sludge in the digestion of organic material, however, it does not yet have a practical protocol for its most widespread development in the Treatment Stations. The present work intends to make a comparison between two SMA methods, one simplified and one automated. In both methods there was inoculation of anaerobic reactor sludge, dilution with nutrient solution and addition of substrate (sodium acetate), in adequate concentrations. For the simplified method, antibiotic flasks were used with manual measurement of biogas production using a glass syringe and methane analysis via chromatography. In the automated method, the AMPTS (Automatic Methane Potential Test System) was used, which provided the results through interface with specific software. The results obtained with the simplified method were more coherent than expected (values around the range of 0.2 to 0.3 gDQOCH4/gSV.d), reliable and of lower cost, considering all the material resources involved, when compared with the obtained with automated method (values around 0.1 gDQOCH4/gSV.d). In addition, it has been found that new practices can be implemented., O teste da atividade metanogênica específica (AME) permite conhecimento sobre o potencial de lodos anaeróbios em digestão de material orgânico, no entanto, ainda não possui protocolo prático para o seu desenvolvimento mais disseminado nas Estações de Tratamento. O presente trabalho avaliou dois métodos de AME, um simplificado e outro automatizado. Em ambos métodos houve inoculação de lodo de reator anaeróbio, diluição com solução nutritiva e adição de substrato (acetato de sódio), em concentrações adequadas. Para o método simplificado foram utilizados frascos de antibiótico com medição manual da produção de biogás, por meio de seringa esmerilhada, e análise de metano via cromatografia. No método automatizado foi utilizado o equipamento AMPTS (Automatic Methane Potential Test System), o qual fornecia os resultados por meio de interface com software específico. Os resultados obtidos com o método simplificado foram mais coerentes ao esperado (valores em torno da faixa de 0,2 a 0,3 gDQOCH4/gSV.d), confiáveis e de custo inferior, considerando todos os recursos materiais envolvidos, quando comparados com os obtidos com método automatizado (valores em torno de 0,1 gDQOCH4/gSV.d). Além disso, verificou-se que novas praticidades podem ser implementadas.

Simultaneous recovery of calcium phosphate granules (CaP granules) and methane from vacuum collected black water (BW), using an upflow anaerobic sludge blanket (UASB) reactor was previously investigated. It was calculated that only 2% of the total phosphorus (P) fed was present as CaP granules whereas 51% of the P accumulated dispersed in the reactor, limiting the applicability of this process for recovery of phosphate. This study proposes adding calcium to increase the P accumulation in the reactor and the production of CaP granules. Calcium was added in a lab-scale UASB reactor fed with BW. An identical UASB reactor was used as reference, to which no calcium was added. The treatment performance was evaluated by weekly monitoring of influent, effluent and produced biogas. Sludge bed development and CaP granulation were assessed through particle size analysis. The composition and structure of CaP granules were chemically and optically assessed. Calcium addition increased accumulation of P in the reactor and formation and growth of granules with size > 0.4 mm diameter (CaP granules). Moreover, with calcium addition, CaP granules contained 5.6 ± 1.5 wt% of P, while without calcium a lower P content was observed (3.7 ± 0.3 wt%). By adding Ca, 89% of the incoming P from BW accumulated in the reactor and 31% was sampled as CaP granules (> 0.4 mm diameter). Addition of 250 mgCa L−1 of BW was the optimum loading found in this study. Furthermore, no significant reduction in CODTotal removal (> 80%) and CH4 production (0.47 ± 0.10 gCOD-CH4 g−1CODTotal-BW) was observed. Therefore, adding calcium can significantly increase the CaP granulation without inhibiting the simultaneous CH4 recovery. This further indicates the potential of this process for phosphate recovery.

The effect of granular activated carbon (GAC) addition on the removal of diclofenac, ibuprofen, metoprolol, galaxolide and triclosan in a up-flow anaerobic sludge blanket (UASB) reactor was studied. Prior to the reactor studies, batch experiments indicated that addition of activated carbon to UASB sludge can decrease micropollutant concentrations in both liquid phase and sludge. In continuous experiments, two UASB reactors were operated for 260 days at an HRT of 20 days, using a mixture of source separated black water and sludge from aerobic grey water treatment as influent. GAC (5.7 g per liter of reactor volume) was added to one of the reactors on day 138. No significant difference in COD removal and biogas production between reactors with and without GAC addition was observed. In the presence of GAC, fewer micropollutants were washed out with the effluent and a lower accumulation of micropollutants in sludge and particulate organic matter occurred, which is an advantage in micropollutant emission reduction from wastewater. However, the removal of micropollutants by adding GAC to a UASB reactor would require more activated carbon compared to effluent post-treatment. Additional research is needed to estimate the effect of bioregeneration on the lifetime of activated carbon in a UASB-GAC reactor.

At cubans universities over the 65 % of students are grant holders and special attention lends itself to the steps of domestic waters generated in communities and university permanences. This work presents the removal of the organic matter in the university community's domestic waters Antonio Maceo of the Universidad de Oriente utilizing, to scale of laboratory two systems: UASB reactor and anaerobic lagoon. The anaerobic systemsevaluated attained a superior COD removal to the 70 % and decrease of bacteria's total coliformes from 72x105 NMP/100 mL to 16 NMP/100 mL. The clarification with alum improves the esthetic characteristics of the outflow. Anyone of variants (UASB or anaerobic lagoon) can be applied for the removal of the organic matter in the university community's domestic waters., En las universidades cubanas más del 65 % de los estudiantes son becarios y se presta especial atención a la gestión de las aguas domésticas generadas en las comunidades y residencias universitarias. Este trabajo presenta la remoción de la materia orgánica en las aguas domésticas de la comunidad universitaria Antonio Maceo de la Universidad de Oriente empleando, a escala de laboratorio, dos sistemas: reactor UASB y laguna anaerobia. Los sistemas anaerobios evaluados, alcanzaron una remoción de la DQO superior al 70 % y una disminución de las bacterias coliformes totales desde 72x10(5) NMP/100 mL hasta 16 NMP/100 mL. La clarificación con alumbre mejora las características estéticas del efluente. Cualquiera de las variantes (UASB o laguna anaerobia) pueden ser aplicadas para la remoción de la materia orgánica en las aguas domésticas de la comunidad universitaria.

At cubans universities over the 65 % of students are grant holders and special attention lends itself to the steps of domestic waters generated in communities and university permanences. This work presents the removal of the organic matter in the university community's domestic waters Antonio Maceo of the Universidad de Oriente utilizing, to scale of laboratory two systems: UASB reactor and anaerobic lagoon. The anaerobic systemsevaluated attained a superior COD removal to the 70 % and decrease of bacteria's total coliformes from 72x105 NMP/100 mL to 16 NMP/100 mL. The clarification with alum improves the esthetic characteristics of the outflow. Anyone of variants (UASB or anaerobic lagoon) can be applied for the removal of the organic matter in the university community's domestic waters., En las universidades cubanas más del 65 % de los estudiantes son becarios y se presta especial atención a la gestión de las aguas domésticas generadas en las comunidades y residencias universitarias. Este trabajo presenta la remoción de la materia orgánica en las aguas domésticas de la comunidad universitaria Antonio Maceo de la Universidad de Oriente empleando, a escala de laboratorio, dos sistemas: reactor UASB y laguna anaerobia. Los sistemas anaerobios evaluados, alcanzaron una remoción de la DQO superior al 70 % y una disminución de las bacterias coliformes totales desde 72x10(5) NMP/100 mL hasta 16 NMP/100 mL. La clarificación con alumbre mejora las características estéticas del efluente. Cualquiera de las variantes (UASB o laguna anaerobia) pueden ser aplicadas para la remoción de la materia orgánica en las aguas domésticas de la comunidad universitaria.

At cubans universities over the 65 % of students are grant holders and special attention lends itself to the steps of domestic waters generated in communities and university permanences. This work presents the removal of the organic matter in the university community's domestic waters Antonio Maceo of the Universidad de Oriente utilizing, to scale of laboratory two systems: UASB reactor and anaerobic lagoon. The anaerobic systemsevaluated attained a superior COD removal to the 70 % and decrease of bacteria's total coliformes from 72x105 NMP/100 mL to 16 NMP/100 mL. The clarification with alum improves the esthetic characteristics of the outflow. Anyone of variants (UASB or anaerobic lagoon) can be applied for the removal of the organic matter in the university community's domestic waters., En las universidades cubanas más del 65 % de los estudiantes son becarios y se presta especial atención a la gestión de las aguas domésticas generadas en las comunidades y residencias universitarias. Este trabajo presenta la remoción de la materia orgánica en las aguas domésticas de la comunidad universitaria Antonio Maceo de la Universidad de Oriente empleando, a escala de laboratorio, dos sistemas: reactor UASB y laguna anaerobia. Los sistemas anaerobios evaluados, alcanzaron una remoción de la DQO superior al 70 % y una disminución de las bacterias coliformes totales desde 72x10(5) NMP/100 mL hasta 16 NMP/100 mL. La clarificación con alumbre mejora las características estéticas del efluente. Cualquiera de las variantes (UASB o laguna anaerobia) pueden ser aplicadas para la remoción de la materia orgánica en las aguas domésticas de la comunidad universitaria.

This research was conducted to study the anaerobic sludge filtration capacity regarding helminth egg removal in upflow anaerobic sludge blanket (UASB) reactors. Two 25 L lab-scale UASB reactors were operated at an ambient temperature which varied between 17.1 and 28.6 °C. Ascaris suum egg was selected as the model egg considering its similarity in terms of size and morphology to Ascaris lumbricoides, a human pathogen. Ascaris suum eggs were obtained from female parasites of infected pigs. The anaerobic sludge filtration capacity was performed applying upflow velocities between 0.09 and 0.68 m·h?1. Three sludge bed heights in the range of 0.30–0.40 m, 0.50–0.60 m and 0.60–0.70 m were applied. These sludge bed heights corresponded to 19%–25%, 31%–38% and 38%–44% of the total reactor height, respectively. Under the mentioned conditions, the average helminth egg removal efficiency was reciprocally correlated to the imposed upflow velocity. The studied lab-scale reactors reported an average helminth egg removal between 34%–100%, 30%–91% and 34%–56%, when the sludge bed in the UASB reactor was 19%–25%, 31%–38% and 38%–44% of the total reactor height, respectively. The decreased filtration capacity at increasing sludge bed heights might be likely related to biogas production and channeling formation. The average helminth egg removal efficiency in the control experiments performed without any sludge bed, by plain sedimentation, varied between 44% and 66%., Water Management, Civil Engineering and Geosciences

This research was conducted to study the anaerobic sludge filtration capacity regarding helminth egg removal in upflow anaerobic sludge blanket (UASB) reactors. Two 25 L lab-scale UASB reactors were operated at an ambient temperature which varied between 17.1 and 28.6 °C. Ascaris suum egg was selected as the model egg considering its similarity in terms of size and morphology to Ascaris lumbricoides, a human pathogen. Ascaris suum eggs were obtained from female parasites of infected pigs. The anaerobic sludge filtration capacity was performed applying upflow velocities between 0.09 and 0.68 m·h?1. Three sludge bed heights in the range of 0.30–0.40 m, 0.50–0.60 m and 0.60–0.70 m were applied. These sludge bed heights corresponded to 19%–25%, 31%–38% and 38%–44% of the total reactor height, respectively. Under the mentioned conditions, the average helminth egg removal efficiency was reciprocally correlated to the imposed upflow velocity. The studied lab-scale reactors reported an average helminth egg removal between 34%–100%, 30%–91% and 34%–56%, when the sludge bed in the UASB reactor was 19%–25%, 31%–38% and 38%–44% of the total reactor height, respectively. The decreased filtration capacity at increasing sludge bed heights might be likely related to biogas production and channeling formation. The average helminth egg removal efficiency in the control experiments performed without any sludge bed, by plain sedimentation, varied between 44% and 66%., Water Management, Civil Engineering and Geosciences

This research was conducted to study the anaerobic sludge filtration capacity regarding helminth egg removal in upflow anaerobic sludge blanket (UASB) reactors. Two 25 L lab-scale UASB reactors were operated at an ambient temperature which varied between 17.1 and 28.6 °C. Ascaris suum egg was selected as the model egg considering its similarity in terms of size and morphology to Ascaris lumbricoides, a human pathogen. Ascaris suum eggs were obtained from female parasites of infected pigs. The anaerobic sludge filtration capacity was performed applying upflow velocities between 0.09 and 0.68 m·h-1. Three sludge bed heights in the range of 0.30–0.40 m, 0.50–0.60 m and 0.60–0.70 m were applied. These sludge bed heights corresponded to 19%–25%, 31%–38% and 38%–44% of the total reactor height, respectively. Under the mentioned conditions, the average helminth egg removal efficiency was reciprocally correlated to the imposed upflow velocity. The studied lab-scale reactors reported an average helminth egg removal between 34%–100%, 30%–91% and 34%–56%, when the sludge bed in the UASB reactor was 19%–25%, 31%–38% and 38%–44% of the total reactor height, respectively. The decreased filtration capacity at increasing sludge bed heights might be likely related to biogas production and channeling formation. The average helminth egg removal efficiency in the control experiments performed without any sludge bed, by plain sedimentation, varied between 44% and 66%

The conversion rate of organic matter in a bioreactor depends on two main factors: the reactor's biological and hydraulic activity (Peña-Varón, Mara & Avella-Rodríguez, 2006). It is therefore necessary to understand treatment systems' hydraulic behavior by using tracer substances in order to determine flow behavior: piston, complete mix, dispersion; the existence of dead zones, short circuits, advective flows, and real hydraulic retention time. The goal of this article is to model the hydraulic behavior of a UASB (Upflow Anaerobic Sludge Blanket) system through a tracer test using rhodamine WT and the stimulus-response technique. The non-ideal flow models used were the tanks in series model and the dispersion model. We thereby determined that the UASB system being studied showed the behavior of a completely mixed reactor with short circuits and dead zones., A taxa de conversão de matéria orgânica em um biorreator depende principalmente de dois fatores: atividade biológica e a hidraulica do reator (Peña-Varón, Mara y Avella-Rodríguez, 2006). Portanto, é necessário conhecer o comportamento hidráulico dos sistemas de tratamento que utilizam substâncias marcadoras para determinar o comportamento de fluxo: pistão, mistura completa, a dispersão; existência de curto-circuitos, zonas mortas, fluxos advectivos e o tempo real de retenção hidráulica. O objetivo deste artigo é modelar o comportamento hidráulico de um sistema UASB-Upflow Anaerobic Sludge Blanket, (UASB-reator anaeróbio de fluxo ascendente em portugues) por um teste traçador usando Rodamina WT através da técnica de estímulo-resposta, os modelos para fluxo não-ideal que foram utilizadas são do modelo de Tanque serie e Modelo Dispersão. Com isto se determinou que o sistema UASB em estudo tem um comportamento de um reactor completamente misturado na presença de curto-circuitos e zonas mortas., La tasa de conversión de la materia orgánica en un biorreactor depende principalmente de dos factores: la actividad biológica y la hidráulica del reactor (Peña-Varón, Mara y Avella-Rodríguez, 2006). Por lo anterior, es necesario conocer el comportamiento hidráulico de los sistemas de tratamiento usando sustancias trazadoras a fin de determinar el comportamiento del flujo: pistón, mezcla completa, dispersión; existencia de zonas muertas, corto-circuitos, flujos advectivos y el tiempo de retención hidráulico real. El objetivo de este artículo es modelar el comportamiento hidráulico de un sistema UASB-Upflow Anaerobic Sludge Blanket (en español RAFA-reactor anaerobio de flujo ascendente), por medio de una prueba de trazadores utilizando Rodamina WT a través de la técnica estímulo-respuesta, los modelos para flujo no ideal que se utilizaron son modelo de tanques en serie y modelo de dispersión. Con ello se determinó que el sistema UASB en estudio tiene un comportamiento de un reactor completamente mezclado con presencia de cortocircuitos y zonas muertas.

Hydrogen-producing granules formation was studied in a CSTR. The aim of this process is to later transfer the mixed liquor to a UASB reactor to reduce its start-up period. Vinasses from a national bioetha­nol-producing industry (from sugar cane) were used as substrate and their anaerobic fermentation was carried out under mesophilic conditions. The seed sludge was collected from an UASB reactor oper­ated in an industrial wastewater treatment plant and it was heat treated to inactivate methanogenic bacteria. Total viable and non-viable material growth curves were generated and it was determined that the exponential growth phase of the thermally pre­treated mixed culture was between 20 and 120 h. Finally, the anaerobic fermentation of the vinasses in batch mode for 70 hours, and then in continuous CSTR mode for 7 days, showed to be an effective method for accelerating the formation of hydrogen-producing granules. Using this method, granules with an average size of 1.24 mm were achieved. The good efficiency of the process is attributed to high mass transfer in the CSTR reactor., Se estudió la formación de gránulos productores de hidrógeno en un reactor CSTR, con el fin de transfe­rirlos luego un reactor UASB y así acortar el tiempo de arranque del mismo. El sustrato utilizado fueron vinazas provenientes de una agroindustria nacional productora de etanol a partir de melazas de caña de azúcar y su fermentación anaerobia se llevó a cabo bajo condiciones mesofílicas. Los lodos para realizar la inoculación del sistema se tomaron de un reactor UASB de una planta de tratamiento de agua industrial, a los cuales se les realizó un tratamiento térmico con el objetivo de inhibir el crecimiento de bacterias metanogénicas. Se generaron curvas de crecimiento de materia viable y no viable total, con las cuales se determinó que la fase de crecimiento exponencial de las bacterias en cultivo mixto pre­tratadas térmicamente se encontraba entre las 20 y las 120 h. Finalmente, la fermentación anaeróbica de las vinazas durante 70 horas en modo “batch” (por lotes) y posteriormente durante 7 días en modo continuo tipo CSTR demostró ser un pro­cedimiento efectivo para acelerar la formación de los gránulos productores de hidrógeno, lográndose obtener gránulos con un tamaño promedio de 1,24 mm. La alta eficiencia del proceso se le atribuye a la elevada transferencia de masa que se obtiene en el reactor CSTR.

Hydrogen-producing granules formation was studied in a CSTR. The aim of this process is to later transfer the mixed liquor to a UASB reactor to reduce its start-up period. Vinasses from a national bioetha­nol-producing industry (from sugar cane) were used as substrate and their anaerobic fermentation was carried out under mesophilic conditions. The seed sludge was collected from an UASB reactor oper­ated in an industrial wastewater treatment plant and it was heat treated to inactivate methanogenic bacteria. Total viable and non-viable material growth curves were generated and it was determined that the exponential growth phase of the thermally pre­treated mixed culture was between 20 and 120 h. Finally, the anaerobic fermentation of the vinasses in batch mode for 70 hours, and then in continuous CSTR mode for 7 days, showed to be an effective method for accelerating the formation of hydrogen-producing granules. Using this method, granules with an average size of 1.24 mm were achieved. The good efficiency of the process is attributed to high mass transfer in the CSTR reactor., Se estudió la formación de gránulos productores de hidrógeno en un reactor CSTR, con el fin de transfe­rirlos luego un reactor UASB y así acortar el tiempo de arranque del mismo. El sustrato utilizado fueron vinazas provenientes de una agroindustria nacional productora de etanol a partir de melazas de caña de azúcar y su fermentación anaerobia se llevó a cabo bajo condiciones mesofílicas. Los lodos para realizar la inoculación del sistema se tomaron de un reactor UASB de una planta de tratamiento de agua industrial, a los cuales se les realizó un tratamiento térmico con el objetivo de inhibir el crecimiento de bacterias metanogénicas. Se generaron curvas de crecimiento de materia viable y no viable total, con las cuales se determinó que la fase de crecimiento exponencial de las bacterias en cultivo mixto pre­tratadas térmicamente se encontraba entre las 20 y las 120 h. Finalmente, la fermentación anaeróbica de las vinazas durante 70 horas en modo “batch” (por lotes) y posteriormente durante 7 días en modo continuo tipo CSTR demostró ser un pro­cedimiento efectivo para acelerar la formación de los gránulos productores de hidrógeno, lográndose obtener gránulos con un tamaño promedio de 1,24 mm. La alta eficiencia del proceso se le atribuye a la elevada transferencia de masa que se obtiene en el reactor CSTR.

The conversion rate of organic matter in a bioreactor depends on two main factors: the reactor's biological and hydraulic activity (Peña-Varón, Mara & Avella-Rodríguez, 2006). It is therefore necessary to understand treatment systems' hydraulic behavior by using tracer substances in order to determine flow behavior: piston, complete mix, dispersion; the existence of dead zones, short circuits, advective flows, and real hydraulic retention time. The goal of this article is to model the hydraulic behavior of a UASB (Upflow Anaerobic Sludge Blanket) system through a tracer test using rhodamine WT and the stimulus-response technique. The non-ideal flow models used were the tanks in series model and the dispersion model. We thereby determined that the UASB system being studied showed the behavior of a completely mixed reactor with short circuits and dead zones., A taxa de conversão de matéria orgânica em um biorreator depende principalmente de dois fatores: atividade biológica e a hidraulica do reator (Peña-Varón, Mara y Avella-Rodríguez, 2006). Portanto, é necessário conhecer o comportamento hidráulico dos sistemas de tratamento que utilizam substâncias marcadoras para determinar o comportamento de fluxo: pistão, mistura completa, a dispersão; existência de curto-circuitos, zonas mortas, fluxos advectivos e o tempo real de retenção hidráulica. O objetivo deste artigo é modelar o comportamento hidráulico de um sistema UASB-Upflow Anaerobic Sludge Blanket, (UASB-reator anaeróbio de fluxo ascendente em portugues) por um teste traçador usando Rodamina WT através da técnica de estímulo-resposta, os modelos para fluxo não-ideal que foram utilizadas são do modelo de Tanque serie e Modelo Dispersão. Com isto se determinou que o sistema UASB em estudo tem um comportamento de um reactor completamente misturado na presença de curto-circuitos e zonas mortas., La tasa de conversión de la materia orgánica en un biorreactor depende principalmente de dos factores: la actividad biológica y la hidráulica del reactor (Peña-Varón, Mara y Avella-Rodríguez, 2006). Por lo anterior, es necesario conocer el comportamiento hidráulico de los sistemas de tratamiento usando sustancias trazadoras a fin de determinar el comportamiento del flujo: pistón, mezcla completa, dispersión; existencia de zonas muertas, corto-circuitos, flujos advectivos y el tiempo de retención hidráulico real. El objetivo de este artículo es modelar el comportamiento hidráulico de un sistema UASB-Upflow Anaerobic Sludge Blanket (en español RAFA-reactor anaerobio de flujo ascendente), por medio de una prueba de trazadores utilizando Rodamina WT a través de la técnica estímulo-respuesta, los modelos para flujo no ideal que se utilizaron son modelo de tanques en serie y modelo de dispersión. Con ello se determinó que el sistema UASB en estudio tiene un comportamiento de un reactor completamente mezclado con presencia de cortocircuitos y zonas muertas.

Hydrogen-producing granules formation was studied in a CSTR. The aim of this process is to later transfer the mixed liquor to a UASB reactor to reduce its start-up period. Vinasses from a national bioetha­nol-producing industry (from sugar cane) were used as substrate and their anaerobic fermentation was carried out under mesophilic conditions. The seed sludge was collected from an UASB reactor oper­ated in an industrial wastewater treatment plant and it was heat treated to inactivate methanogenic bacteria. Total viable and non-viable material growth curves were generated and it was determined that the exponential growth phase of the thermally pre­treated mixed culture was between 20 and 120 h. Finally, the anaerobic fermentation of the vinasses in batch mode for 70 hours, and then in continuous CSTR mode for 7 days, showed to be an effective method for accelerating the formation of hydrogen-producing granules. Using this method, granules with an average size of 1.24 mm were achieved. The good efficiency of the process is attributed to high mass transfer in the CSTR reactor., Se estudió la formación de gránulos productores de hidrógeno en un reactor CSTR, con el fin de transfe­rirlos luego un reactor UASB y así acortar el tiempo de arranque del mismo. El sustrato utilizado fueron vinazas provenientes de una agroindustria nacional productora de etanol a partir de melazas de caña de azúcar y su fermentación anaerobia se llevó a cabo bajo condiciones mesofílicas. Los lodos para realizar la inoculación del sistema se tomaron de un reactor UASB de una planta de tratamiento de agua industrial, a los cuales se les realizó un tratamiento térmico con el objetivo de inhibir el crecimiento de bacterias metanogénicas. Se generaron curvas de crecimiento de materia viable y no viable total, con las cuales se determinó que la fase de crecimiento exponencial de las bacterias en cultivo mixto pre­tratadas térmicamente se encontraba entre las 20 y las 120 h. Finalmente, la fermentación anaeróbica de las vinazas durante 70 horas en modo “batch” (por lotes) y posteriormente durante 7 días en modo continuo tipo CSTR demostró ser un pro­cedimiento efectivo para acelerar la formación de los gránulos productores de hidrógeno, lográndose obtener gránulos con un tamaño promedio de 1,24 mm. La alta eficiencia del proceso se le atribuye a la elevada transferencia de masa que se obtiene en el reactor CSTR.

Hydrogen-producing granules formation was studied in a CSTR. The aim of this process is to later transfer the mixed liquor to a UASB reactor to reduce its start-up period. Vinasses from a national bioetha­nol-producing industry (from sugar cane) were used as substrate and their anaerobic fermentation was carried out under mesophilic conditions. The seed sludge was collected from an UASB reactor oper­ated in an industrial wastewater treatment plant and it was heat treated to inactivate methanogenic bacteria. Total viable and non-viable material growth curves were generated and it was determined that the exponential growth phase of the thermally pre­treated mixed culture was between 20 and 120 h. Finally, the anaerobic fermentation of the vinasses in batch mode for 70 hours, and then in continuous CSTR mode for 7 days, showed to be an effective method for accelerating the formation of hydrogen-producing granules. Using this method, granules with an average size of 1.24 mm were achieved. The good efficiency of the process is attributed to high mass transfer in the CSTR reactor., Se estudió la formación de gránulos productores de hidrógeno en un reactor CSTR, con el fin de transfe­rirlos luego un reactor UASB y así acortar el tiempo de arranque del mismo. El sustrato utilizado fueron vinazas provenientes de una agroindustria nacional productora de etanol a partir de melazas de caña de azúcar y su fermentación anaerobia se llevó a cabo bajo condiciones mesofílicas. Los lodos para realizar la inoculación del sistema se tomaron de un reactor UASB de una planta de tratamiento de agua industrial, a los cuales se les realizó un tratamiento térmico con el objetivo de inhibir el crecimiento de bacterias metanogénicas. Se generaron curvas de crecimiento de materia viable y no viable total, con las cuales se determinó que la fase de crecimiento exponencial de las bacterias en cultivo mixto pre­tratadas térmicamente se encontraba entre las 20 y las 120 h. Finalmente, la fermentación anaeróbica de las vinazas durante 70 horas en modo “batch” (por lotes) y posteriormente durante 7 días en modo continuo tipo CSTR demostró ser un pro­cedimiento efectivo para acelerar la formación de los gránulos productores de hidrógeno, lográndose obtener gránulos con un tamaño promedio de 1,24 mm. La alta eficiencia del proceso se le atribuye a la elevada transferencia de masa que se obtiene en el reactor CSTR.

Hydrogen-producing granules formation was studied in a CSTR. The aim of this process is to later transfer the mixed liquor to a UASB reactor to reduce its start-up period. Vinasses from a national bioetha­nol-producing industry (from sugar cane) were used as substrate and their anaerobic fermentation was carried out under mesophilic conditions. The seed sludge was collected from an UASB reactor oper­ated in an industrial wastewater treatment plant and it was heat treated to inactivate methanogenic bacteria. Total viable and non-viable material growth curves were generated and it was determined that the exponential growth phase of the thermally pre­treated mixed culture was between 20 and 120 h. Finally, the anaerobic fermentation of the vinasses in batch mode for 70 hours, and then in continuous CSTR mode for 7 days, showed to be an effective method for accelerating the formation of hydrogen-producing granules. Using this method, granules with an average size of 1.24 mm were achieved. The good efficiency of the process is attributed to high mass transfer in the CSTR reactor., Se estudió la formación de gránulos productores de hidrógeno en un reactor CSTR, con el fin de transfe­rirlos luego un reactor UASB y así acortar el tiempo de arranque del mismo. El sustrato utilizado fueron vinazas provenientes de una agroindustria nacional productora de etanol a partir de melazas de caña de azúcar y su fermentación anaerobia se llevó a cabo bajo condiciones mesofílicas. Los lodos para realizar la inoculación del sistema se tomaron de un reactor UASB de una planta de tratamiento de agua industrial, a los cuales se les realizó un tratamiento térmico con el objetivo de inhibir el crecimiento de bacterias metanogénicas. Se generaron curvas de crecimiento de materia viable y no viable total, con las cuales se determinó que la fase de crecimiento exponencial de las bacterias en cultivo mixto pre­tratadas térmicamente se encontraba entre las 20 y las 120 h. Finalmente, la fermentación anaeróbica de las vinazas durante 70 horas en modo “batch” (por lotes) y posteriormente durante 7 días en modo continuo tipo CSTR demostró ser un pro­cedimiento efectivo para acelerar la formación de los gránulos productores de hidrógeno, lográndose obtener gránulos con un tamaño promedio de 1,24 mm. La alta eficiencia del proceso se le atribuye a la elevada transferencia de masa que se obtiene en el reactor CSTR.

This study presents the potential of combining anaerobic grey water sludge treatment with black water in an up-flow anaerobic sludge blanket (UASB) reactor to improve energy recovery within source-separated sanitation concepts. Black water and the mixture of black water and grey water sludge were compared in terms of biochemical methane potential (BMP), UASB reactor performance, chemical oxygen demand (COD) mass balance and methanization. Grey water sludge treatment with black water increased the energy recovery by 23% in the UASB reactor compared to black water treatment. The increase in the energy recovery can cover the increased heat demand of the UASB reactor and the electricity demand of the grey water bioflocculation system with a surplus of 0.7 kWh/cap/y electricity and 14 MJ/cap/y heat. However, grey water sludge introduced more heavy metals in the excess sludge of the UASB reactor and might therefore hinder its soil application.

The present study aims to evaluate the removal efficiency of COD and BOD in a UASB reactor. This research was carried out in sewage treatment plant in the municipality of Crato - EC in an upflow anaerobic sludge blanket (UASB), pilot scale, belonging to the Faculty of Technology - CENTEC Cariri - EC. And the monitoring was conducted by means of samples collected biweekly at the inlet (influent) and output (effluent) from the reactor, which allowed to analyze the following parameters: pH, temperature, chemical oxygen demand (COD), biochemical demand for oxygen demand (BOD). According to the results obtained it was concluded that pH in the influent and effluent showed satisfactory results remaining within the neutral range, in the case of temperature values in the influent and effluent was considered optimal for the anaerobic digestion. With regard to the efficiency of removal of organic substance in the form of COD and BOD values were around 44 and 76% and 16% and 76, respectively. However, it should be noted that the removal efficiency of COD and BOD was low. This was attributed to the discontinuity of the power of the UASB reactor is negligible at night., O presente trabalho tem como objetivo avaliar a eficiência de remoção de DQO e DBO em um reator UASB. Esta pesquisa realizou-se na estação de tratamento de esgotos do município do Crato - CE, em um reator anaeróbio de fluxo ascendente com manta de lodo (reator UASB), em escala piloto, pertencente à Faculdade de Tecnologia – CENTEC Cariri – CE. E o monitoramento, foi realizado por meio de amostras coletadas quinzenalmente na entrada (afluente) e saída (efluente) do reator, o que possibilitou-se analisar os seguintes parâmetros: pH, temperatura, demanda química de oxigênio (DQO), demanda bioquímica de oxigênio (DBO). De acordo com os resultados obtidos conclui-se que o pH no afluente e efluente apresentou resultados satisfatórios mantendo-se dentro da faixa neutra, no que se refere aos valores de temperatura no afluente e efluente foi considerada ótima para a digestão anaeróbia. Com relação à eficiência de remoção de matéria orgânica expressa na forma de DQO e DBO, apresentaram valores em torno de 44 e 76 % e de 16 e 76%, respectivamente. Contudo, deve-se ressaltar que a eficiência de remoção de DQO e de DBO foi baixa. Este fato foi atribuído à descontinuidade da alimentação do reator UASB ser praticamente desprezível no período noturno.

The present study aims to evaluate the removal efficiency of COD and BOD in a UASB reactor. This research was carried out in sewage treatment plant in the municipality of Crato - EC in an upflow anaerobic sludge blanket (UASB), pilot scale, belonging to the Faculty of Technology - CENTEC Cariri - EC. And the monitoring was conducted by means of samples collected biweekly at the inlet (influent) and output (effluent) from the reactor, which allowed to analyze the following parameters: pH, temperature, chemical oxygen demand (COD), biochemical demand for oxygen demand (BOD). According to the results obtained it was concluded that pH in the influent and effluent showed satisfactory results remaining within the neutral range, in the case of temperature values in the influent and effluent was considered optimal for the anaerobic digestion. With regard to the efficiency of removal of organic substance in the form of COD and BOD values were around 44 and 76% and 16% and 76, respectively. However, it should be noted that the removal efficiency of COD and BOD was low. This was attributed to the discontinuity of the power of the UASB reactor is negligible at night., O presente trabalho tem como objetivo avaliar a eficiência de remoção de DQO e DBO em um reator UASB. Esta pesquisa realizou-se na estação de tratamento de esgotos do município do Crato - CE, em um reator anaeróbio de fluxo ascendente com manta de lodo (reator UASB), em escala piloto, pertencente à Faculdade de Tecnologia – CENTEC Cariri – CE. E o monitoramento, foi realizado por meio de amostras coletadas quinzenalmente na entrada (afluente) e saída (efluente) do reator, o que possibilitou-se analisar os seguintes parâmetros: pH, temperatura, demanda química de oxigênio (DQO), demanda bioquímica de oxigênio (DBO). De acordo com os resultados obtidos conclui-se que o pH no afluente e efluente apresentou resultados satisfatórios mantendo-se dentro da faixa neutra, no que se refere aos valores de temperatura no afluente e efluente foi considerada ótima para a digestão anaeróbia. Com relação à eficiência de remoção de matéria orgânica expressa na forma de DQO e DBO, apresentaram valores em torno de 44 e 76 % e de 16 e 76%, respectivamente. Contudo, deve-se ressaltar que a eficiência de remoção de DQO e de DBO foi baixa. Este fato foi atribuído à descontinuidade da alimentação do reator UASB ser praticamente desprezível no período noturno.

The upflow anaerobic sludge blanket (UASB) reactor is widely used around the world to treat variety of domestic andindustrial wastewater with three main advantages: production of biogas as renewable energy, no need of support structure for development of microorganisms and high rate treatment efficiency with low rate of biomass production. This study evaluates the effect of temperature on biogas production and CODtotal removal in Line 4-UASB system treating domestic wastewater in Hammarby Sjöstadsverk. Eight parameters were examined including the following: Influent and effluent temperature, pH, influent CODtotal, influent rate, effluent CODtotal, volatile fatty acids, biogas production rate and methane concentration. There are eight set temperature and each is stabilized for seven days. The biogas production analysis is focus on UASB 1. Temperature rising from 19°C to 35°C achieves a general benefit result in methane yield rate and CODtotal removal efficiency. The best methane yield rate and CODtotal removal rate are 0.167l/gCODtotal and 56.84% respectively at highest working temperature 33.4°C with OLR 3.072gCODtotal/(l*day) and HRT 4.2h., Den ökande energiförbrukningen i världen och utsläpp av växthusgaser (GHG) gör det nödvändigt att söka nya hållbara energikällor för att matcha efterfrågan på energi i framtiden. Rötningsteknik med organiskt avfall som förnybar energikälla, ger biogas som i genomsnitt består av 78% CH4, 22% av CO2och spår av H2S (<0.5%), är en idealisk kostnadseffektiv metod. Den Uppåt flödande anaeroba slambäddsreaktorn(UASB) med största fördelarna: biogasproduktion som förnybar energi, hög belastning och hög behandlingseffektivitet med låg produktion av biomassa, inget behov av stödstruktur för utveckling av mikroorganismer, är den viktigaste typen för anaerobt reningssystem. Det finns flera faktorer som påverkar UASB-reaktorns prestanda, såsom temperatur, pH, HRT, Uppåtriktat flödeshastighet, OLR, SRT och VFA. I denna studie är huvudsyftet att med fokus på utvärdering av temperaturpåverkan på biogasproduktion och CODtotal avlägsnat i UASB-systemet Linje 4 som behandlar hushållsspillvatten i Hammarby Sjöstadsverk. Analysen avbiogasproduktionen fokuserades på UASB reaktor 1. Åtta parametrar övervakades för att kontrollera skick inklusive inflöde och utflöde, temperatur, pH, CODtotal inflöde, strömningshastighet för inflöde, CODtotal utflöde, flyktiga fettsyror VFA, biogasproduktionstakt och metankoncentration. Försöken utfördes vid åtta inställda temperaturnivåer och varje nivå stabiliserades i sju dagar. pH och VFA-värde var stabilt under hela försöket. Resultatetvisar att temperaturen har en större inverkan på metanavkastningen och CODtotal avlägsnat än belastningen, OLR. Då temperaturen höjs från 19°C till 35°C erhålls en större metanavkastning och större CODtotal avlägsnat. Den största metanavkastningen och CODtotal avlägsnat är 0,167l/g CODtotal respektive 56.84% vid den högsta arbetstemperaturen 33.4°C med OLR 3.072g CODtotal/(l * dag) och HRT 4.2h. Energibalansen vid olika arbetstemperaturer visaratt det finns en stor skillnad i energibehov för uppvärmning och utbyte aven

The upflow anaerobic sludge blanket (UASB) reactor is widely used around the world to treat variety of domestic andindustrial wastewater with three main advantages: production of biogas as renewable energy, no need of support structure for development of microorganisms and high rate treatment efficiency with low rate of biomass production. This study evaluates the effect of temperature on biogas production and CODtotal removal in Line 4-UASB system treating domestic wastewater in Hammarby Sjöstadsverk. Eight parameters were examined including the following: Influent and effluent temperature, pH, influent CODtotal, influent rate, effluent CODtotal, volatile fatty acids, biogas production rate and methane concentration. There are eight set temperature and each is stabilized for seven days. The biogas production analysis is focus on UASB 1. Temperature rising from 19°C to 35°C achieves a general benefit result in methane yield rate and CODtotal removal efficiency. The best methane yield rate and CODtotal removal rate are 0.167l/gCODtotal and 56.84% respectively at highest working temperature 33.4°C with OLR 3.072gCODtotal/(l*day) and HRT 4.2h., Den ökande energiförbrukningen i världen och utsläpp av växthusgaser (GHG) gör det nödvändigt att söka nya hållbara energikällor för att matcha efterfrågan på energi i framtiden. Rötningsteknik med organiskt avfall som förnybar energikälla, ger biogas som i genomsnitt består av 78% CH4, 22% av CO2och spår av H2S (<0.5%), är en idealisk kostnadseffektiv metod. Den Uppåt flödande anaeroba slambäddsreaktorn(UASB) med största fördelarna: biogasproduktion som förnybar energi, hög belastning och hög behandlingseffektivitet med låg produktion av biomassa, inget behov av stödstruktur för utveckling av mikroorganismer, är den viktigaste typen för anaerobt reningssystem. Det finns flera faktorer som påverkar UASB-reaktorns prestanda, såsom temperatur, pH, HRT, Uppåtriktat flödeshastighet, OLR, SRT och VFA. I denna studie är huvudsyftet att med fokus på utvärdering av temperaturpåverkan på biogasproduktion och CODtotal avlägsnat i UASB-systemet Linje 4 som behandlar hushållsspillvatten i Hammarby Sjöstadsverk. Analysen avbiogasproduktionen fokuserades på UASB reaktor 1. Åtta parametrar övervakades för att kontrollera skick inklusive inflöde och utflöde, temperatur, pH, CODtotal inflöde, strömningshastighet för inflöde, CODtotal utflöde, flyktiga fettsyror VFA, biogasproduktionstakt och metankoncentration. Försöken utfördes vid åtta inställda temperaturnivåer och varje nivå stabiliserades i sju dagar. pH och VFA-värde var stabilt under hela försöket. Resultatetvisar att temperaturen har en större inverkan på metanavkastningen och CODtotal avlägsnat än belastningen, OLR. Då temperaturen höjs från 19°C till 35°C erhålls en större metanavkastning och större CODtotal avlägsnat. Den största metanavkastningen och CODtotal avlägsnat är 0,167l/g CODtotal respektive 56.84% vid den högsta arbetstemperaturen 33.4°C med OLR 3.072g CODtotal/(l * dag) och HRT 4.2h. Energibalansen vid olika arbetstemperaturer visaratt det finns en stor skillnad i energibehov för uppvärmning och utbyte aven

Hydrogen production from desugared molasses (DM) was investigated in both batch and continuous reactors using thermophilic mixed cultures enriched from digested manure by load shock (loading with DM concentration of 50.1 g-sugar/L) to suppress methanogens. H2 gas, free of methane, was produced during batch cultivations, at different (DM) concentrations ranging from 1.5 g-sugars/L to 50.1 g-sugars/L. The highest yield of 237 ml-H2/g-sugar was achieved during the DM batch fermentation at concentration of 2.1 g-sugars/L, whereafter the yield decreased with increasing DM concentration. The enriched hydrogen producing mixed culture achieved from the 16.7 g-sugars/L DM batch cultivation was immobilized on heat treated anaerobic sludge granules in an up-flow anaerobic sludge blanket (UASB) reactor. The UASB reactor, operated at a hydraulic retention time (HRT) of 24 h fed with 16.7 g-sugars/L DM showed good performance with a satisfactory hydrogen yield of 269.5 ml-H2/g-sugar and rate of 4500 ml H2/l⋅d. Fluorescent in situ hybridization (FISH) analysis of the microbial community of sludge from batch fermentation and the UASB-granules after 54 days of operation, was dominated by Thermoanaerobacterium spp., which are key players in fermentative hydrogen production of DM under thermophilic conditions. Furthermore, the granules in the UASB reactor were also significantly containing Thermoanaerobacterium spp. and phylum Firmecutes (most Clotridium, Bacillus and Desulfobacterium) and Thermoanaerobacterium thermosaccharolyticum with a relative abundance of 36%, 27%, and 10% of total microorganisms, respectively. This study shows that hydrogen production could be efficiently facilitated by using anaerobic granules as a carrier, where microbes from mixed culture enriched in the DM batch cultivation were immobilized on, in an UASB reactor.

The two-stage process for extreme thermophilic hydrogen and thermophilic methane production from wheat straw hydrolysate was investigated in up-flow anaerobic sludge bed (UASB) reactors. Specific hydrogen and methane yields of 89ml-H2/g-VS (190ml-H2/g-sugars) and 307ml-CH4/g-VS, respectively were achieved simultaneously with the overall VS removal efficiency of 81% by operating with total hydraulic retention time (HRT) of 4days . The energy conversion efficiency was dramatically increased from only 7.5% in the hydrogen stage to 87.5% of the potential energy from hydrolysate, corresponding to total energy of 13.4kJ/g-VS. Dominant hydrogen-producing bacteria in the H2-UASB reactor were Thermoanaerobacter wiegelii, Caldanaerobacter subteraneus, and Caloramator fervidus. Meanwhile, the CH4-UASB reactor was dominated with methanogens of Methanosarcina mazei and Methanothermobacter defluvii. The results from this study suggest the two stage anaerobic process can be effectively used for energy recovery and for stabilization of hydrolysate at anaerobic conditions.

This research describes the feasibility of applying a UASB reactor for the treatment of concentrated black (toilet) water at 25 °C. On average 78% of the influent load of COD at an HRT of 8.7 days was removed. Produced methane can be converted to 56 MJ/p/y as electricity and 84 MJ/p/y as heat by combined heat and power (CHP). Minimum reactor volume at full scale was calculated to be 63L per person (for black water containing 16 gCOD/L produced at 5 L/p/d) and this is more than two times smaller than other type of reactors for anaerobic treatment of concentrated black water

This paper aimed at evaluating the effect of nitrate on anaerobic azo dye reduction by using mesophilic bioreactors, in the absence and in the presence of redox mediators. Two anaerobic bioreactors were operated in parallel with a hydraulic retention time (HRT) of ten hours; ethanol was used as co-substrate. The results showed that the bioreactors were efficient on dye reduction, and the ethanol showed to be a good electron donor to sustain it. The redox mediator AQDS increased the rates of reductive decolourisation, but its effect was not so remarkable compared to the previous experiments conducted. Contrary to the raised hypothesis that nitrate addition could decrease the colour removal efficiency and catalytic properties of the redox mediators, no effect of nitrate was observed in the bioreactors