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Aim of this research was to treat the organics enriched Paper and Pulp Industry (PPI) effluents using multi-metal tolerant predominant indigenous bacterial species. In addition, assessing the potential of treated bacterial biomass as a single cell protein (SCP). The multi-metal tolerant Streptomyces tuirus OS1 was enumerated from the Paper and Pulp Industry (PPI) effluents was identified through standard molecular characterization. S. tuirus OS1 proficiently ameliorated organic contaminants in PPI effluent in the in study at 35 °C, 45 °C, and 25 °C. Fortunately, the S. tuirus OS1 considerably increased the dissolved oxygen level in treated PPI effluent in 30 days of bioremediation process. Interestingly, at 35 °C of bioremediation process the S. tuirus OS1 demonstrated increased dried biomass (7.1 g L

In Werkpakket 1 (uitgevoerd door WUR Plant Breeding) is gezocht naar de meest optimale stammen van Ceriporiopsis subvermispora. Hiervoor zijn 30 stammen (20 homokaryons en 10 kruisingen) binnen de soort C. subvermispora onderzocht op hun vermogen om tarwestro en ingekuild bermgras selectief van hemicellulose en lignine te ontdoen. Op basis van de resultaten van Werkpakket 1 blijken C. subvermispora stammen MES15023 (monokaryon), MES15032 (monokaryon) en MES14706 (dikaryon) het meest selectief in de afbraak van lignine in zowel tarwestro als bermgras en is het resultaat van doorgroeien van de substraten met deze stammen een relatieve verrijking in cellulose. In Werkpakket 3 (eveneens uitgevoerd door WUR Plant Breeding) zijn verschillende typen biomassa voorbehandeld met de uit Werkpakket 1 als beste naar voren komende stammen. Er werd daarbij gewerkt met twee mogelijke toepassingen van het op te leveren behandelde materiaal. Deze toepassingen waren biogasproductie (op basis van tarwestro) en productie van vezelmateriaal voor de papier industrie (op basis van Miscanthus, Natuurgras, Lisdodde, Vlaslemen en Hennepscheven). De bovengenoemde materialen werden doorgroeid met 3 C. subvermispora stammen; MES15032 als beste monokaryon in WP1, MES14706 als beste dikaryon in WP1 en MES13094 als referentie uit de eerdere biogas testen. Het met schimmel doorgroeide materiaal werd op verschillende momenten tijdens de kolonisatie door de schimmels bemonsterd en het bemonsterde materiaal werd geanalyseerd op vezelsamenstelling. Stro substraat raakte (evenals in Werkpakket 1, goed doorgroeid met alle drie de schimmelstammen. Ook Miscanthus, vlaslemen en hennepscheven raakten goed doorgroeid met beide geteste schimmelstammen. In tegenstelling tot tarwestro en miscanthus, raakte het natuurgras substraat slechts met moeite doorgroeid. Lisdodde raakte nauwelijks gekoloniseerd door beide geteste schimmelstammen. Uitgaande van de selectieve verrijking van substraten met cellulose (door afbraak van hemicellulose en lignine) bleek vooral na 8 weken incubatie het relatieve gehalte aan cellulose in het tarwestro sterk omhoog te zijn gegaan, ten koste van 19% verlies aan droge stof. Na 12 weken was het relatieve gehalte aan cellulose nog sterker gestegen, maar dit ging ten koste van 35% van de droge stof. In Miscanthus steeg de verhouding cellulose/lignine van 4.4 bij aanvang van de schimmelincubatie gestaag naar 9.8 na 19 weken incubatie met stam MES 15032, maar dit ging ten koste van 20% van de droge stof. Stam MES14706 gaf minder goede resultaten te zien (cellulose/lignine verhouding 6.4 na 19 weken incubatie). Vlaslemen , natuurgras en hennepscheven werden uitsluitend geanalyseerd na 12 weken doorgroeiing met de schimmels. In geval van vlaslemen steeg de verhouding cellulose/lignine van 2.1 bij aanvang naar 6.6 na 12 weken incubatie met stam MES15032. Dit ging echter ten koste van 24% van de droge stof. Bij stam MES14706 steeg de verhouding cellulose/lignine slechts naar een waarde 3.4 na 12 weken incubatie. In natuurgras steeg de verhouding cellulose/lignine niet erg sterk na 12 weken incubatie met de schimmels, maar er verdween wel ongeveer 44% (MES14706) en 49% (MES15032) van de droge stof. In natuurgras bleek de afbraak niet erg selectief; zowel cellulose, hemicellulose als lignine werden allemaal afgebroken. In geval van hennepscheven steeg de verhouding cellulose/lignine bijzonder sterk na 12 weken incubatie met MES15032; van 3.6 bij aanvang naar 18.5 na 12 weken. Dit ging echter ten koste van 50% van de droge stof. Bij incubatie met MES14706 steeg de verhouding cellulose/lignine na 12 weken incubatie naar 7.1 en dit ging ten koste van 37% van de droge stof. Vanwege de slechte kolonisatie van lisdodde door de beide schimmels is besloten om dit substraat niet verder te analyseren. Binnen Werkpakket 5 zijn door CNC Grondstoffen een reeks aan experimenten uitgevoerd gericht op het opschalen van de teelt van C. subvermispora. In de commerciele praktijk wordt een substraat bedoeld voor schimmelkweek gepasteuriseerd door het substraat door eigen microbiele activiteit te laten opwarmen tot waarden rond 60-65oC. De door CNC Grondstoffen uitgevoerde experimenten hebben echter geen van allen succes gehad. In de solid state fermentor bleek het niet mogelijk om de gewenste temperaturen te bereiken. In een experiment waarin gebruik is gemaakt van commercieel beschikbaar substraat op basis van tarwestro bleek echter dat Ceriporiopsis subvermispora niet in staat bleek om dat substraat te koloniseren (terwijl schimmels zoals Pleurotus ostreatus (de oesterzwam) en Lentinula edodes (shiitake) daar in de commerciële praktijk geen enkel probleem mee hebben. Mogelijk heeft C. subvermispora een probleem met de hoge pH van het commerciële substraat. Pogingen om een selectief substraat te maken door tarwestro te verzuren met citroenzuur waren echter eveneens niet succesvol. Het is duidelijk dat de opschaling van het systeem nog enig werk behoeft.

Petroleum-based plastics, such as PP, PE, PVC, etc., have become an important source of environmental pollution due to their hard degradation, posing a serious threat to the human health. Isolating nanocellulose from abundant biomass waste resources and further integrating the nanocellulose into hydrophobic transparent film (i.e., nanopaper), to replace the traditional nondegradable plastic film, is of great significance for solving the problem of environmental pollution and achieving sustainable development of society. This study respectively extracted nanocellulose from the branches of Amorpha fruticosa Linn., wheat straw, and poplar residues via combined mechanical treatments of grinding and high-pressure homogenization. Among them, the nanocellulose derived from the Amorpha fruticosa has a finer structure, with diameter of about 10 nm and an aspect ratio of more than 500. With the nanocellulose as building block, we constructed hydrophilic nanopaper with high light transmittance (up to 90%) and high mechanical strength (tensile strength up to 110 MPa). After further hybridization by incorporating nano-silica into the nanopaper, followed by hydrophobic treatment, we built hydrophobic nanopaper with transmittance over 82% and a water contact angle of about 102&deg, that could potentially replace transparent plastic film and has wide applications in food packaging, agricultural film, electronic device, and other fields.

The use of non-potable water (such as seawater) is an attractive alternative for water intensive processes such as biomass pretreatment and saccharification steps in the production of biochemicals and biofuels. Identification and application of halotolerant enzymes compatible with high-salt conditions may reduce the energy needed for non-potable water treatment and decrease waste treatment costs. Here we present the biochemical properties of a halotolerant endo-1,4-β-xylanase produced by Aspergillus clavatus in submerged fermentation, using paper sludge (XPS) and sugarcane bagasse (XSCB), and its potential application in the hydrolysis of agroindustrial residues. The peptide mass fingerprint and amino acid sequencing of the XPS and XSCB enzymes showed primary structure similarities with an endo-1,4-β-xylanase from Aspergillus clavatus (XYNA_ASPCL). Both enzyme preparations presented good thermal stability at 50 °C and were stable over a wide range of pH and Vmax up to 2450 U/mg for XPS. XPS and XSCB were almost fully stable even after 24 h of incubation in the presence of up to 3 M NaCl, and their activity were not affected by 500 mM NaCl. Both enzyme preparations were capable of hydrolyzing paper sludge and sugarcane bagasse to release reducing sugars. These characteristics make this xylanase attractive to be used in the hydrolysis of biomass, particularly with brackish water or seawater.

Fly ash (FA) from biomass combustion and biological sludge (S), both wastes from the pulp and paper industry, were granulated in different proportions (90% FA + 10% S, and 70% FA + 30% S w/w, dry weight basis, dw) and used to recover the functionality of soils affected by mining activities (Aljustrel, Iberian Pyrite Belt), with and without the application of municipal solid waste compost (MSWC). Application doses of both mixtures were 2.5, 5.0 and 10% (w/w, dw). These materials corrected soil acidity to circumneutral values and increased extractable P and K concentrations. A significant increase in soil organic matter (from 0.6 to 0.8–1.5% w/w, dw) and N content (from 0.04 to 0.09–0.12% w/w, dw) was also observed, but only when MSWC was applied. The soil was already heavily contaminated with Cu, Pb and Zn and the application of amendments did not increase their pseudo-total concentrations. The CaCl2 extractable fractions of both Cu and Zn decreased to very low values. The improvement in soil quality, compared to fertilizer only treatment, was further evidenced by the increase in some soil enzymatic activities (dehydrogenase, β-glucosidase and cellulase), with a better response for the granules with the higher proportion of biological sludge, as well as by the decrease in the soil-water extract toxicity towards different organisms (Daphnia magna, Thamnocephalus platyurus, and Pseudokirchneriella subcapitata). Agrostis tenuis germinated and grew during the first month only in the amended pots, but, after that, a considerable phytotoxic effect was evident. This was mainly attributed to salt stress or to some specific ionic toxicity. In conclusion, to establish a long-term plant cover in mining soils amended with biomass ash-based materials, the selection of plants with higher resistance to salinity and/or the stabilization of the amendments, to reduce their soluble salt content, is recommended.

Waste paper, a major fraction of municipal solid waste, has a potential to serve as renewable feedstock for the biorefineries of fuels, chemicals and materials due to rich in cellulose and abundant at low cost. This study evaluates the possibility of waste office paper (WOP) to serve as a potential feedstock for the biorefinery production of poly (3-hydroxybutyrate). In this study, the WOP was pretreated, enzymatically saccharified and the hydrolysate was used for PHB production. The hydrolysate mainly consists of glucose (22.70 g/L) and xylose (1.78 g/L) and the corresponding sugar yield was about 816 mg/g. Ammonium sulphate and C/N ratio 20 were identified as most favorable for high yield of PHB. The batch fermentation of Cupriavidus necator using the pretreated WOP hydrolysate resulted in cell biomass, PHB production and PHB content of 7.74 g/L, 4.45 g/L and 57.52%, respectively. The volumetric productivity and yield achieved were 0.061 g/L/h and 0.210 g/g sugar, respectively. The results suggested that WOP could be a potential alternative feedstock for the biorefinery production of bioplastics.

In the pulp bleaching industry, enzymes with robust activity at high pH and temperatures are desirable for facilitating the pre-bleaching process with simplified processing and minimal use of chlorinated compounds. To engineer an enzyme for this purpose, we determined the crystal structure of the Xyn12.2 xylanase, a xylan-hydrolyzing enzyme derived from the termite gut symbiont metagenome, as the basis for structure-based protein engineering to improve Xyn12.2 stability in high heat and alkaline conditions. Engineered cysteine pairs that generated exterior disulfide bonds increased the kcat of Xyn12.2 variants and melting temperature at all tested conditions. These improvements led to up to 4.2-fold increases in catalytic efficiency at pH 9.0, 50°C for 1h and up to 3-fold increases at 60°C. The most effective variants, XynTT and XynTTTE, exhibited 2-3-fold increases in bagasse hydrolysis at pH 9.0 and 60°C compared to the wild-type enzyme. Overall, engineering arginines and phenylalanines for increased pKa and hydrogen bonding improved enzyme catalytic efficiency at high stringency conditions. These modifications were the keys to enhancing thermostability and alkaliphilicity in our enzyme variants, with XynTT and XynTTTE being especially promising for their application to the pulp and paper industry.

The fundamentals of pyrolysis, its latest developments, the different conditions of the process and their relative residues are of great importance to evaluate the applicability of the pyrolysis process within the waste management sector and waste treatments. In particular the type of residues and their further use or treatment is of extreme interest as they could become the source of secondary raw material or generate beneficial influence in waste treatments. The main area of focus of this paper is the investigation of the link between the pyrolysis conditions, the chemical and mineralogical composition of their products and the benefits of pyrolysis in the waste management sector. More specific the paper covers the fast, intermediate and slow pyrolysis of organic and a mixture of inorganic/organic charge from households. The catalysts influence during fast pyrolysis on products yields and composition is not being considered in the review.

Cellulase (mainly endoglucanase, EG) has been used in pulp modification for improving paper quality through environmentally friendly process. But low activity in alkaline pH and high filter paper activity (FPA) were still obstacles for extending the cellulase application in papermaking industry. In the study, an alkali-tolerant EG gene of Bacillus subtilis Y106 was homologous over-expressed for obtaining suitable enzyme used in pulp modification. The engineering strain could produce the crude enzyme with more alkali-tolerant EG and little PFA. Potential of the crude enzyme in modification of different pulps were investigated. It was found that the enzyme could be used for improving drainage and strength properties of pulps from softwood, hardwood and non-wood materials, especially non-wood pulp such as wheat straw pulp. The underlying mechanisms of pulp modification and different effects on various types of pulps by the EG treatment were also discussed by studying the change in fibers characteristics and fiber bonding.

Biovalorization of pulp and paper activated sludge to value-added products could be an effective alternative to traditional sludge management methods, which tend to pose serious environmental issues. Since pulp and paper activated sludge consists of microbial biomass, cellulose, hemicellulose and lignin and thus, could be subjected to different hydrolysis methods to solubilize sludge solids and release simple sugars to form value-added products by the microbial fermentation process. Hence, different sludge hydrolysis methods have been summarized in this review paper. However, hydrolysis of lignocellulosic materials generates variety of toxic compounds during hydrolysis and causes detrimental effects. Therefore, different toxic compounds and their impact on microorganisms, cellulolytic enzymes and fermentation process have been discussed in detail and recent strategies to counteract the problems of inhibitors have also been briefly explained.

Mixed sludge from a pulp and paper mill was hydrothermally carbonized at 180–260 °C for 0.5–5 h with the use of HCl or NaOH for determining the effect of acid and base additions during sludge carbonization. Based on the results carbonization was mainly governed by dehydration, depolymerization and decarboxylation of sludge components. Additive type had a statistically significant effect on hydrochar carbon content and carbon and energy yield, of which especially energy yield increased through the use of HCl. The theoretical energy efficiencies of carbonization increased with decreasing reaction temperature, retention time and the use of HCl and suggested that the energy requirement could be covered by the energy content of attained hydrochar. The BOD5/COD-ratios of analyzed liquid samples indicated that the dissolved organic components could be treated by conventional biological methods.

The potential of cellulase enzymes in the developing and ongoing "biorefinery" industry has provided a great motivation to develop an efficient cellulase mixture. Recent work has shown how important the role that the so-called accessory enzymes can play in an effective enzymatic hydrolysis. In this study, three newest Novozymes Cellic CTec cellulase preparations (CTec 1/2/3) were compared to hydrolyze steam pretreated lignocellulosic substrates and model substances at an identical FPA loading. These cellulase preparations were found to display significantly different hydrolytic performances irrelevant with the FPA. And this difference was even observed on the filter paper itself when the FPA based assay was revisited. The analysis of specific enzyme activity in cellulase preparations demonstrated that different accessory enzymes were mainly responsible for the discrepancy of enzymatic hydrolysis between diversified substrates and various cellulases. Such the active role of accessory enzymes present in cellulase preparations was finally verified by supplementation with β-glucosidase, xylanase and lytic polysaccharide monooxygenases AA9. This paper provides new insights into the role of accessory enzymes, which can further provide a useful reference for the rational customization of cellulase cocktails in order to realize an efficient conversion of natural lignocellulosic substrates.

Peat-based growing media are not ecologically sustainable and peat extraction threatens sensitive peatland ecosystem. In this study, olive-stone waste (OSW) and paper waste (PW) were used in different ratios—as growing media—for ornamental crop production, as peat (P) substitutes. Marigold (Calendula officinalis L.), petunia (Petunia x hybrita L.) and matthiola (Matthiola incana L.) plants were grown in (1) P (100%), (2) P:OSW (90%:10%), (3) P:OSW (70%:30%), and (4) P:OSW:PW (60%:20%:20%). The physicochemical properties of these substrates and the effects on plant growth were determined. The addition of 10–30% OSW into the substrate increased marigold height compared to plants grown in 100% peat. No differences in plant size, plant biomass (leaves and flowers), and dry matter content were found. Adding PW, in combination with OSW, maintained marigold height and total number of flowers produced to similar levels as in plants grown in 100% peat. In matthiola, adding 30% OSW into the substrate reduced plant size and fresh weight, but not plant height. No differences were observed when plants grew in lower OSW (i.e., 10%) content. Petunia’s height, its total number of flowers and flower earliness (flower opening) were increased in the presence of OSW compared to the plants grown in 100% peat. The addition of OSW did not affect petunia’s size and fresh weight among treatments. The addition of PW suppressed several plant growth-related parameters for both matthiola and petunia. The insertion of OSW did not change leaf chlorophyll content whereas the presence of PW decreased chlorophylls for marigold, petunia, and matthiola. Both OSW and PW altered the content of total phenolics and antioxidant capacity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) in leaves and flowers for marigold and petunia. Both 30% OSW and PW increased antioxidative enzyme metabolism due to the increased damage index and lipid peroxidation observed in plants. Leaf N and P content decreased in PW-based media, while matthiola displayed visual phytotoxicity symptoms when PW was added into the substrate. The present work indicates that up to 30% of OSW can replace peat for marigold and petunia growing and only up to 10% of OSW for matthiola, while the addition of PW on top of OSW is not recommended, so further research is needed.

This study presents dark fermentative hydrogen gas production from acid hydrolysed waste paper towel hydrolysate. Firstly, Box-Behnken statistical experiment design was used to investigate glucose production from waste paper towel by acid hydrolysis. S/L ratio, hydrolysis time and pH were chosen as independent variables while glucose concentration in the hydrolysate was the objective function. Highest glucose concentration of 32.17 g/L was obtained at S/L ratio of 100 g/L, pH 0 (gauge pH) and 180 min hydrolysis time. All variables were found to have significant effect on glucose formation. Glucose concentration increased by increasing the S/L ratio and hydrolysis time, but decreased by increasing the pH. Secondly, the hydrolysate obtained at most convenient hydrolysis conditions was subjected to lime putty treatment for the removal of 5-HMF and SO4 2-. Thirdly, H2 gas was produced from the detoxified hydrolysate by dark fermentation. Maximum H2 formation yield, rate and H2 percentage in the gas phase were 1.02 mol H2/mol glucoseconsumed, 130.22 mL H2/g biomass.h and 43%, respectively. The remaining 5-HMF after lime treatment was effectively removed in dark fermentation. © 2017, Springer Science+Business Media Dordrecht.

The activated sludge process is an old technology, but still the most commonly used one for treatment of wastewater. Despite the wide spread usage the technology still suffers from instability (Tandoi et al. 2006) and high operating cost. Activated sludge processes often carry a large solids inventory. Managing the total inventory without interference is the key component of the optimization process described in this paper. Use of nutrients is common in pulp and paper effluent treatment. Feeding enough nutrients to support the biomass growth is a delicate balance. Overfeeding or underfeeding of nutrients can result in higher costs. Detrimental substances and toxic components in effluents entering a biological treatment system can cause severe, long lasting disturbances (Hynninen & Ingman 1998; Bergeron & Pelletier 2004). A LumiKem test kit is used to measure biological activity with adenosine triphosphate (ATP) in a pulp and paper mill. ATP data are integrated with other standardized mill parameters. Measurements of active volatile suspended solids based on ATP can be used to quantify the living biomass in the activated sludge process and to ensure that sufficient biomass is present in order to degrade the wastewater constituents entering the process. Information about active biomass will assist in optimizing sludge inventories and feeding of nutrients allowing the living biomass to re-populate to create optimal efficiency. ATP measurements can also be used to alert operators if any components toxic to bacteria are present in wastewater. The bio stress index represents the stress level experienced by the microbiological population. This parameter is very useful in monitoring toxicity in and around bioreactors. Results from the wastewater process optimization and ATP measurements showed that treatment cost could be reduced by approximately 20–30% with fewer disturbances and sustained biological activity compared to the reference period. This was mainly achieved by the removal of detrimental substances and optimized nutrient dosage.

The fundamentals of pyrolysis, its latest developments, the different conditions of the process and its residues are of great importance in evaluating the applicability of the pyrolysis process within the waste management sector and in waste treatment. In particular the types of residue and their further use or treatment is of extreme interest as they could become the source of secondary raw materials or be used for energy generation in waste treatments. The main area of focus of this paper is the investigation of the link between the pyrolysis conditions, the chemical and mineralogical composition of their products and the benefits of pyrolysis in the waste management sector. More specifically the paper covers the fast, intermediate and slow pyrolysis of organic waste and mixtures of inorganic and organic waste from households. The influence of catalysts during fast pyrolysis on the product yield and composition is not being considered in this review. This reported work was conducted as part of the “Design Optimisation of the HERU Waste Treatment System” project in Brunel University London that was funded by Manik Ventures Limited.

The main aim of this work was to study the removal efficiency of Pb from synthetic and industrial wastewaters by using biomass fly ashes. The biomass fly ashes were produced in a biomass boiler of a pulp and paper industry. Three concentrations of Pb2+ were tested in the synthetic wastewater (1, 10 and 1000 mg Pb/L). Moreover, two different wastewaters were collected in an industrial wastewater treatment plant (IWWTP) of an industry of lead-acid batteries: (i) wastewater of the equalization tank, and (ii) IWWTP effluent. All the wastewaters were submitted to coagulation–flocculation tests with a wide range of biomass fly ashes dosage (expressed as Solid/Liquid – S/L – ratios). All supernatants were characterized for chemical and ecotoxicological parameters. The use of biomass fly ashes has reduced significantly the Pb concentration in the synthetic wastewater and in the wastewaters collected in the IWWTP. For example, the definitive coagulation–flocculation assays performed over the IWWTP effluent presented a very low concentration of Pb (0.35 mg/L) for the S/L ratio of 1.23 g/L. Globally, the ecotoxicological characterization of the supernatants resulting from the coagulation–flocculation assays of all wastewaters has indicated an overall reduction on the ecotoxicity of the crude wastewaters, due to the removal of Pb.

Xylanase is commonly applied in pulp and paper industries to ease cost-related and environmental pressures. The effect of xylanase treatment on pulp bleaching is well-established, however, few studies were conducted on the effects of xylanase treatment in pulp yellowing, especially the mechanism of pulp yellowing inhibition by xylanase treatment. In this study, pure xylanase (EC 3.2.1.8) was applied to treat wheat straw chemical pulp (CP) and poplar chemi-thermo-mechanical pulp (CTMP) to determine their effects on pulp brightness and on light- and heat-induced yellowing. The xylanase treatment decreased the post-color number of the pulps during light- and heat-induced yellowing. However, differences were observed in the yellowing inhibition between the wheat straw CP and poplar CTMP. The changes in chemical components of pulps after the xylanase treatment, for example, lignin, hemicellulose, and HexA contents, and analysis of UV–vis absorption spectra and Fourier transform infrared-attenuated total reflectance spectrum were used to explore the pulp yellowing inhibition causes by the xylanase treatment.

This article describes a study on the viability of using waste from the paper industry: biomass boiler ash and green liquor dregs to fabricate mortars and concretes. Both types of ash were characterized by obtaining their chemical and mineralogical composition, their organic matter content, granulometry, adsorption and other common tests for construction materials. Seven different mortars were fabricated, one for reference made up of cement, sand, and water, three in which 10, 20, or 30% of the cement was replaced by biomass ash, and three others in which 10, 20, or 30% of the cement was replaced with dregs. Test specimens were fabricated with these mortars to conduct flexural and compression tests. Flexural strength is reduced for all the mortars studied. Compressive strength increases for the mortars fabricated with biomass ash and decreases for the mortar with dregs. Finally, 5 concretes were made, one of them as a reference (neither biomass ash nor dregs added), two of them with replacements of 10 and 20% of biomass ash instead of cement and another two with replacements of 10 and 20% of dregs instead of cement. The compressive and tensile splitting strength increase when a 10% of ash is replaced and decrease in all the other cases. The modulus of elasticity always decreases.

The thermogravimetric and calorimetric characteristics during pyrolysis of wood, paper, textile and polyethylene terephthalate (PET) plastic in municipal solid wastes (MSW), and co-pyrolysis of biomass-derived and plastic components with and without torrefaction were investigated. The active pyrolysis of the PET plastic occurred at a much higher temperature range between 360 °C and 480 °C than 220–380 °C for the biomass derived components. The plastic pyrolyzed at a heating rate of 10 °C/min had the highest maximum weight loss rate of 18.5 wt%/min occurred at 420 °C, followed by 10.8 wt%/min at 340 °C for both paper and textile, and 9.9 wt%/min at 360 °C for wood. At the end of the active pyrolysis stage, the final mass of paper, wood, textile and PET was 28.77%, 26.78%, 21.62% and 18.31%, respectively. During pyrolysis of individual MSW components at 500 °C, the wood required the least amount of heat at 665.2 J/g, compared to 2483.2 J/g for textile, 2059.4 J/g for paper and 2256.1 J/g for PET plastic. The PET plastic had much higher activation energy of 181.86 kJ/mol, compared to 41.47 kJ/mol for wood, 50.01 kJ/mol for paper and 36.65 kJ/mol for textile during pyrolysis at a heating rate of 10 °C/min. H2O and H2 peaks were observed on the MS curves for the pyrolysis of three biomass-derived materials but there was no obvious H2O and H2 peaks on the MS curves of PET plastic. There was a significant interaction between biomass and PET plastic during co-pyrolysis if the biomass fraction was dominant. The amount of heat required for the co-pyrolysis of the biomass and plastic mixture increased with the increase of plastic mass fraction in the mixture. Torrefaction at a proper temperature and time could improve the grindability of PET plastic. The increase of torrefaction temperature and time did not affect the temperature where the maximum pyrolytic rates occurred for both biomass and plastic but decreased the maximum pyrolysis rate of biomass and increased the maximum pyrolysis rate of PET plastic. The amount of heat for the pyrolysis of biomass and PET mixture co-torrefied at 280 °C for 30 min was 4365 J/g at 500 °C, compared to 1138 J/g for the pyrolysis of raw 50% wood and 50% PET mixture at the same condition.

The goal of this study is to evaluate the feasibility of PHA biosynthesis from kraft mill effluent using the batch system evaluating the biomass origin and C:N relationship influence. To evaluate feasibility, batch assays were carried out. Also, two levels of the BOD 5 :N:P relationship (100:5:1 and 100:1:0.2) and three different sludge origins were considered. Inocula were obtained from activated sludge treatment plants for a) sewage (SAS), b) paper mill (PAS) and c) kraft (KAS). The results show that the maximum Biological Oxygen Demand (BOD 5 ) and Chemical Oxygen Demand (COD) removal was 80.5% and 59.7% respectively using KAS as inoculum. In these assays, kinetics constants were 17.9±3.2 mg L −1 and 46.5±1.2 d −1 for ( K COD ) and (r max ), respectively under a BOD 5 :N:P relationship of 100:5:1. The maximum PHA accumulation was obtained under a BOD 5 :N:P relationship of 100:1:0.2 on the third day of batch assays using PAS sludge with 25.72% of the cells accumulating PHA and on the fifth day in batch using SAS and KAS sludge with 25.85% and 30.40% of cells accumulating PHA, respectively. Yields obtained for the 100:1:0.2 relationships ranged from 0.10–0.14 mg PHA mg −1 COD.

The use of treated pulp mill effluent on eucalyptus plantation appears to be an attractive option for plant nutrition and water supply. It also constitutes a supplementary treatment process and a final disposal option for the mill effluent. This study aimed at the investigation and evaluation of the effects of bleached kraft pulp mill treated effluent on three typical Brazilian soils used for eucalyptus plantation. The effluent was characterized and five different application rates, defined according to the load of sodium, were tested in controlled environment experiments (greenhouse). After effluent application over a six month period an increase in the salinity of the studied soils was observed, although no soil dispersion was detected. The low content of some nutrients in the treated effluent indicated the need for fertilizer complementation. In general, the best biomass productivity and plant growth results were obtained in fine textured soil at a loading rate of 6.49 t Na ha−1. The good response of the soil-plant system under different effluent application rates showed the feasibility for the eucalyptus irrigation if adequate management practices and monitoring are carried out.

10 páginas, 4 figuras, 10 tablas -- PAGS NROS. 2211-2220, The great amount of pollutants released from kraft pulp processes, mainly from cooking and bleaching stages, is one of the most relevant environmental problems in this type of industry. New bleaching sequences are being studied based on the use of oxidative enzymes from fungal cultures. In this study, the bleaching systems consisting of Laccase and different mediators such as 1-hydroxybenzotriazole, violuric acid, syringaldehyde and methyl syringate in the bleaching sequence of Eucalyptus globulus kraft pulp were applied. The main objective of this study is to evaluate the aerobic and anaerobic biodegradability and toxicity to Vibrium fischeri of generated L-stage and total bleaching sequence effluents. The highest levels of aerobic and anaerobic degradation of the generated effluents were achieved for treatments with laccase plus violuric acid, with 80% of aerobic degradation and 68% of anaerobic biodegradation. V. fischeri toxicity was remarkably reduced for all the effluents after aerobic degradation. Copyright (c) 2009 Elsevier Ltd. All rights reserved., This work has been partially financed by the European Project NMP2-CT-2006-026456 BIORENEW and the Xunta de Galicia (Project Reference: PGIDIT09MDS010262PR).

In activated sludge (AS) biotreatment, septic compounds such as volatile organic acids and reduced sulphur compounds have been frequently cited as a major cause of Thiothrix and Type 021N filamentous bulking. These filaments are common in Canadian pulp and paper biotreatment systems, where they cause settling problems in secondary clarifiers. We conducted a 14-week study of a TMP/newsprint mill effluent to characterize the septic compounds entering the biotreatment, and to determine correlations with AS biomass characteristics and biotreatment operating parameters. A significant correlation was found between the sludge volume index, the abundance of Type 021N, and the propionic acid (PA) concentration in the primary clarified effluent. PA also induced a significant change in the flocculating bacteria size distribution determined by digital imaging. Consequently, the correlation observed between PA and Type 021N bulking is an indirect effect of inhibition of floc-forming microorganisms, giving a competitive advantage to filaments.

The objective of this work was to evaluate the semi-continuous post-treatment of anaerobically-pre-treated weak black liquor (anaerobic effluent, AnE) by aerobic post-treatment using hybrid pellets of Trametes versicolor. The latter consisted of fungus immobilized onto holm oak sawdust (mixed or double pellets) or a mixture of holm oak sawdust and powdered activated carbon (triple pellets). First, a semi-continuous experiment was run to compare the effectiveness of triple and mixed pellets in agitated flasks for 15 cycles of 7 days each. A second extended batch test was implemented with 500 mL AnE and triple pellets to give 400 mg fungal biomass; some units were spiked with protease inhibitor. In the first experiment, triple pellets displayed consistently higher removal efficiencies of pollutant parameters than double pellets (10 to 15% higher), although overall averages were moderate and no statistical significance to the difference could be set because of the noise of fluctuations. Periodic fluctuations of removal were characterized by three periods of approximately six cycles each with maximum removals occurring at cycles 3–4, 7–9, 13, and 14. Evaluating pooled removals of the latter cycles showed that triple pellets were significantly more effective than double pellets, with removal efficiencies as high as 47% of COD, colour, and absorbance at 254 nm (A254). In general, protease activity seemed to increase in the third period (last six cycles), whereas activities of MnP, LiP and Lac significantly decreased. In the second experiment, pollutant removals and enzymatic activities of triple pellets with protease inhibitor were significantly higher than those of units without added protease inhibitor. These results indicate that protease could be the main cause of periodic falls of pollutant removal efficiencies found in the first experiment.

The complexity of residual toxic organics from biologically treated effluents of pulp and paper mills is a serious concern. To date, it has been difficult to choose the best treatment technique because each of the available options has advantages and drawbacks. In this study, two different treatment techniques using laboratory-scale aerobic sequencing batch reactors (SBRs) were tested with the same real recycled paper mill effluent to evaluate their treatment efficiencies. Two attached-growth SBRs using granular activated carbon (GAC) with and without additional biomass and a suspended-growth SBR were used in the treatment of real recycled paper mill effluent at a chemical oxygen demand (COD) level in the range of 800–1300 mg/L, a fixed hydraulic retention time of 24 h and a COD:N:P ratio of approximately 100:5:1. The efficiency of this biological treatment process was studied over a 300-day period. The six most important wastewater quality parameters, namely, chemical oxygen demand (COD), turbidity, ammonia (expressed as NH 3 –N), phosphorus (expressed as PO 4 3 –P), colour, and suspended solids (SS), were measured to compare the different treatment techniques. It was determined that these processes were able to almost completely and simultaneously eliminate COD (99%) and turbidity (99%); the removals of NH 3 –N (90–100%), PO 4 3 –P (66–78%), colour (63–91%), and SS (97–99%) were also sufficient. The overall performance results confirmed that an attached-growth SBR system using additional biomass on GAC is a promising configuration for wastewater treatment in terms of performance efficiency and process stability under fluctuations of organic load. Hence, this hybrid system is recommended for the treatment of pulp and paper mill effluents.

Highlights • Steam explosion of copier paper reduces xylose and produces inhibitors. • Steam explosion at SF 3.6 and 3.9 increased initial rates of saccharification. • Steam explosion at moderate severities may reduce processing times. • Co-steam explosion of waste paper and wheat straw reduces inhibitor production., This study evaluated steam (SE) explosion on the saccharification and simultaneous saccharification and fermentation (SSF) of waste copier paper. SE resulted in a colouration, a reduction in fibre thickness and increased water absorption. Changes in chemical composition were evident at severities greater than 4.24 resulting in a loss of xylose and the production of breakdown products known to inhibit fermentation (particularly formic acid and acetic acid). SE did not improve final yields of glucose or ethanol, and at severities 4.53 and 4.83 reduced yields probably due to the effect of breakdown products and fermentation inhibitors. However, at moderate severities of 3.6 and 3.9 there was an increase in initial rates of hydrolysis which may provide a basis for reducing processing times. Co-steam explosion of waste copier paper and wheat straw attenuated the production of breakdown products, and may also provide a basis for improving SSF of lignocellulose.

Climate change mitigation benefits from the land sector are not being fully realised because of uncertainty and controversy about the role of native forest management. The dominant policy view, as stated in the IPCC’s Fifth Assessment Report, is that sustainable forest harvesting yielding wood products, generates the largest mitigation benefit. We demonstrate that changing native forest management from commercial harvesting to conservation can make an important contribution to mitigation. Conservation of native forests results in an immediate and substantial reduction in net emissions relative to a reference case of commercial harvesting. We calibrated models to simulate scenarios of native forest management for two Australian case studies: mixed-eucalypt in New South Wales and Mountain Ash in Victoria. Carbon stocks in the harvested forest included forest biomass, wood and paper products, waste in landfill, and bioenergy that substituted for fossil fuel energy. The conservation forest included forest biomass, and subtracted stocks for the foregone products that were substituted by non-wood products or plantation products. Total carbon stocks were lower in harvested forest than in conservation forest in both case studies over the 100-year simulation period. We tested a range of potential parameter values reported in the literature: none could increase the combined carbon stock in products, slash, landfill and substitution sufficiently to exceed the increase in carbon stock due to changing management of native forest to conservation. The key parameters determining carbon stock change under different forest management scenarios are those affecting accumulation of carbon in forest biomass, rather than parameters affecting transfers among wood products. This analysis helps prioritise mitigation activities to focus on maximising forest biomass. International forest-related policies, including negotiations under the UNFCCC, have failed to recognize fully the mitigation value of native forest conservation. Our analyses provide evidence for decision-making about the circumstances under which forest management provides mitigation benefits.

This paper reports the continuous reductive amination of different molecules, including biomass-related compounds, over carbon-supported FeNi nanoparticles obtained on the basis of inexpensive and abundant metal precursors and cellulose. A biorefinery case study for the preparation of pyrrolidones via acid-catalyzed hydrolysis of glucose followed by reductive amination of the obtained levulinic acid is described.

Gluconic acid production was investigated using an enzymatic hydrolysate of waste office automation paper in a culture of Aspergillus niger. In repeated batch cultures using flasks, saccharified solution medium (SM) did not show any inhibitory effects on gluconic acid production compared to glucose medium (GM). The average gluconic acid yields were 92% (SM) and 80% (GM). In repeated batch cultures using SM in a turbine blade reactor (TBR), the gluconic acid yields were 60% (SM) and 67% (GM) with 80-100 g/l of gluconic acid. When pure oxygen was supplied the production rate increased to four times higher than when supplying air. Remarkable differences in the morphology of A. niger and dry cell weight between SM and GM were observed. The difference in morphology may have caused a reduction of oxygen transfer, resulting in a decrease in gluconic acid production rate in SM.

In this work, hardwood spent sulfite liquor (HSSL), a complex feedstock originating from the pulp industry, was tested for the first time as a substrate for polyhydroxyalkanoate (PHA) production by a mixed microbial culture (MMC) under aerobic dynamic feeding (ADF) conditions. A sequencing batch reactor (SBR) fed with HSSL was operated for 67 days and the selected MMC reached a maximum PHA content of 67.6%. The MMC demonstrated a differential utilization of the carbon sources present in HSSL. Acetic acid was fully consumed, while xylose and lignosulphonates were partially consumed (30% and 14%, respectively). The selected culture was characterized by Fluorescence in Situ Hybridization (FISH). Bacteria belonging to the three main classes were identified: Alpha-(72.7 +/- 4.0%), Beta-(11.1 +/- 0.37%) and Gammaproteobacteria (10.3 +/- 0.3%). Within Alphaproteobacteria, a small amount of Paracoccus (4.2 +/- 0.51%) and Defluvicoccus related to Tetrad Forming Organisms (9.0 +/- 0.28%) were detected. (C) 2014 Elsevier Ltd. All rights reserved.

The Domtar Papers pulp and paper mill in Windsor, Quebec, Canada, investigated the potential for anaerobic treatment of contaminated kraft mill condensates. The objectives of this project were to assess the technical feasibility of replacing the steam stripper with anaerobic treatment, to provide basic information for the design of an anaerobic treatment process for condensates, and to provide information on treated condensate quality for eventual reuse. The project involved extensive chemical characterization of condensates, followed by treatability tests. The tests included laboratory bench-scale tests and on-site pilot testing using direct feed from the process. Characterization showed that the organic content of the condensates was essentially methanol, as expected, but that foul evaporator condensates had high sulfide contents. It was found that undiluted foul condensates at the Windsor mill are toxic to the anaerobic biomass because of these high concentrations of sulfides. Treatment of combined condensates is possible at an approximate volumetric loading of 10 to 12 g/L.d chemical oxygen demand (COD) with good production of biogas (0.35 L/g of COD removed) and excellent methanol removal (better than 95%). The biogas produced is of excellent fuel quality with close to 90% methane, but with a high sulfide content (close to 4%).

The use of waste wood as an energy carrier has increased during the last decade. However, the higher levels of alkali metals and chlorine in waste wood compared to virgin biomass can promote the formation of deposits and organic pollutants. Here, the effect of fuel composition and the inhibitory effects of ammonium sulfate, (NH4)2SO4, on the concentrations of persistent organic pollutants (POPs) in the flue gas of a lab-scale combustor was investigated. Ammonium sulfate is often used as a corrosion-preventing additive and may also inhibit formation of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). In addition to PCDDs and PCDFs, polychlorinated naphthalenes (PCN) and biphenyls (PCB) were also analyzed. It was found that the flue gas composition changed dramatically when (NH4)2SO4 was added: CO, SO2, and NH3 levels increased, while those of HCl decreased to almost zero. However, the additive's effects on POP formation were less pronounced. When (NH4)2SO4 was added to give an S:Cl ratio of 3, only the PCDF concentration was reduced, indicating that this ratio was not sufficient to achieve a general reduction in POP emissions. Conversely, at an S:Cl ratio of 6, significant reductions in the WHO-TEQ value and the PCDD and PCDF contents of the flue gas were observed. The effect on the PCDF concentration was especially pronounced. PCN formation seemed to be promoted by the elevated CO concentrations caused by adding (NH4)2SO4.

International audience; The literature on the presence of heavy metals in contaminated wastes is reviewed. Various categories of materials produced from domestic and industrial activities are included, but municipal solid waste, which is a more complex material, is excluded. This review considers among the most abundant the following materials - wood waste including demolition wood, phytoremediation scavengers and chromated copper arsenate (CCA) timber, sludges including de-inking sludge and sewage sludge, chicken litter and spent pot liner. The partitioning of the metals in the ashes after combustion or gasification follows conventional behaviour, with most metals retained, and higher concentrations in the finer sizes due to vaporisation and recondensation. The alkali metals have been shown to catalyse the biomass conversion, particularly lithium and potassium, although other metals are active to a lesser extent. The most prevalent in biomass is potassium, which is not only inherently active, but volatilises to become finely distributed throughout the char mass. Because the metals are predominantly found in the ash, the effectiveness of their removal depends on the efficiency of the collection of particulates. The potential for disposal into soil depends on the initial concentration in the feed material.

Pigmentation of paper induced by fungi is one of the most complex phenomenons because it involves living organisms growing on a heterogeneous paper substrate. A novel approach to the study of interfaces of fungi and paper in black stains produced by pigmented Dematiaceous fungi with meristematic growth was undertaken applying surface metrology techniques: confocal laser scanning microscope (CLSM) white-light, confocal chromatic aberration profilometer (LCA) and scanning electron microscope in variable pressure (SEM-VP); fungal morphology was examined with transmitted light microscopy (TLM). The role of paper topography and surface morphology in fungi-induced biodeterioration was investigated elucidating some of the dynamic interactions of fungi with paper, spatial distribution of biological deposits, inclusions in paper matrix, and patterns of fungal growth on paper thus contributing to a better understanding of biodeterioration of paper-based cultural heritage. So far, to the authors' knowledge, there are no published reports on the investigation of interfaces of bio-stains and paper utilizing surface metrology techniques.

Cellulosic wastes, from sources such as low-quality cardboard and paper, are regarded as potential feedstocks for bioethanol production. One pathway from these cellulosic materials to ethanol is saccharification (hydrolysis) followed by fermentation. Saccharification is commonly performed using enzymes that are able to cleave the cellulosic structure to smaller units, preferably to glucose monomers. During the hydrolysis, mixing conditions have a considerable impact on the performance of the enzymes. Thus mixing conditions in the hydrolysis tank can also influence the downstream operations and, consequently, the overall economy of the bioethanol process. In this experimental study, four types of impeller, at different hydrolysis conditions were used. The effect of mixing on the glucose yield and on the filtration characteristics of the hydrolysate was evaluated. It was shown that not only the sugar yield depended on the mixing conditions: the effect on the solid–liquid separation step was even more significant. Post-print / Final draft

Lignocellulosic biomass offers economic and environmental advantages over corn starch for biofuels production. However, its fractionation currently requires energy-intensive pretreatments, due to the lignin chemical resistance and complex cell wall structure. Recently, ionic liquids have been used to dissolve biomass at high temperatures. In this study, thin sections of poplar wood were swollen by ionic liquid (1-ethyl-3-methylimidazolium acetate) pretreatment at room temperature. The samples contract when rinsed with deionized water. The controlled expansion and contraction of the wood structure can be used to incorporate enzymes and catalysts deep into the wood structure for improved pretreatments and accelerated cellulose hydrolysis. As a proof of concept, silver and gold nanoparticles of diameters ranging from 20 to 100 nm were incorporated at depths up to 4 mum. Confocal surface-enhanced Raman images at different depths show that a significant number of nanoparticles were incorporated into the pretreated sample, and they remained on the samples after rinsing. Quantitative X-ray fluorescence microanalyses indicate that the majority of nanoparticle incorporation occurs after an ionic liquid pretreatment of less than 1 h. In addition to improved pretreatments, the incorporation of materials and chemicals into wood and paper products enables isotope tracing, development of new sensing, and imaging capabilities.

The ability of aquatic plants to absorb, translocate and concentrate metals has led to the development of various plant-based treatment systems. The potential to accumulate metals like iron, nickel, manganese and copper by Trapa bipinosa was assessed by subjecting them to different effluent concentrations of pulp and paper industry under laboratory conditions. Trapa showed the ability to accumulate substantial amounts of the metals during a short span of one week. When the plants were grown in different concentrations they caused significant reduction in various parameters like dissolved oxygen, biological oxygen demand, chemical oxygen demand, total alkalinity total hardness, chloride and sulphate. While there was an increase in biomass, no visible phytotoxic symptoms were shown by treated plants.

Switchgrass is a promising feedstock for value-added applications due to its high productivity, potentially low requirements for agricultural inputs and positive environmental impacts. The objective of this paper is to review published research on the conversion of switchgrass into bioethanol and other value-added products. Environmental benefits associated with switchgrass include the potential for carbon sequestration, nutrient recovery from runoff, soil remediation and provision of habitats for grassland birds. Pretreatment of switchgrass is required to improve the yields of fermentable sugars. Based on the type of pretreatment, glucose yields range from 70% to 90% and xylose yields range from 70% to 100% after hydrolysis. Following pretreatment and hydrolysis, ethanol yields range from 72% to 92% of the theoretical maximum. Other value-added uses of switchgrass include gasification, bio-oil production, newsprint production and fiber reinforcement in thermoplastic composites. Future prospects for research include increased biomass yields, optimization of feedstock composition for bioenergy applications, and efficient pentose fermentation to improve ethanol yields.