Effect of endogenous hydrolytic enzymes pretreatment on the anaerobic digestion of sludge

Yu, Shuyu; Zhang, Guangming; Li, Jianzheng; Zhao, Zhigang; Kang, Xiangtao

doi:10.1016/j.biortech.2013.07.087

Cited by 161 publications

(58 citation statements)

References 16 publications

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“…In another previous study, no increase in methane yields from enzymatically (mixture of cellulases, proteases and lipases) pre-treated pulp and paper mill (kraft/CTMP) secondary sludge was noticed when the methane yield of the enzymes and chelating mixture was taken into account (Karlsson et al 2011 ; Table 21). Nevertheless, the enzymatic pre-treatment of municipal secondary sludge with amylases and proteases was reported to increase methane yields, both alone and together (Yu et al 2013). These results thus highlight the significance of use of suitable enzymes for each substrate.…”

Section: Pre-treatments To Improve Anaerobic Digestion Of Pulp and Pamentioning

confidence: 68%

Screening pretreatment methods to enhance thermophilic anaerobic digestion of pulp and paper mill wastewater treatment secondary sludge

Bayr

Kaparaju

Rintala

2013

Chemical Engineering Journal

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Esitetään Jyväskylän yliopiston matemaattis-luonnontieteellisen tiedekunnan suostumuksella julkisesti tarkastettavaksi yliopiston Ylistönrinteellä, salissa YAA303 toukokuun 23. päivänä 2014 kello 12.Academic dissertation to be publicly discussed, In this thesis, the anaerobic digestion of industrial by-products from meat and pulp and paper industry were studied. These materials, which are treated mainly like wastes, were seen to be potential substrates for anaerobic digestion. Methane yields of ca. 700 dm 3 kg volatile solids (VS)added -1 were obtained for slaughterhouse wastes, alone and in co-digestion with rendering wastes. On the other hand, methane yields of 190-240 dm 3 kgVSadded -1 were obtained in the monodigestion of pulp and paper industry primary sludge, and 150-170 dm 3 kgVSadded -1 in the co-digestion of primary sludge with secondary sludge. In the digestion of slaughterhouse and rendering wastes, mesophilic conditions were more stable, and the feasible organic loading rates (OLRs) were 1-1.5 kgVS m -3 d -1 and hydraulic retention times (HRTs) were 50 d. For pulp and paper mill wastewater sludge, thermophilic conditions were more stable with the feasible OLRs of 1-2 kgVS m -3 d -1 and the HRTs of 14-32 d. The digestion processes of these industrial by-products can easily turn unstable. In the digestion of slaughterhouse and rendering wastes, process imbalance may occur due to inhibition from intermediate products like volatile fatty acids, long-chain fatty acids and ammonia. On the contrary, in the digestion of pulp and paper mill wastewater sludge, the low nitrogen content and low pH may cause problems. It was observed that the more stable digestion process of slaughterhouse waste is achieved by additive of Co, Ni, Se, W, Fe and HCl. In addition, in pulp and paper mill secondary sludge digestion, hydrothermal pretreatment, among the studied 12 single or combined pre-treatments, increased the methane yield by 19-31 %. In conclusion, the digestion of two different kinds of industrial by-products was seen to be feasible, although operational conditions should be optimised and possibly enhancement methods used to ensure the stable digestion processes of these vulnerable organic materials.

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Section: Pre-treatments To Improve Anaerobic Digestion Of Pulp and Pamentioning

confidence: 68%

Screening pretreatment methods to enhance thermophilic anaerobic digestion of pulp and paper mill wastewater treatment secondary sludge

Bayr

Kaparaju

Rintala

2013

Chemical Engineering Journal

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“…It has been shown that a combination of chemical and enzymatic pretreatment of bamboo waste, using commercial cellulase and alkaline, can lead to significantly enhanced chemical oxygen demand (COD) solubilization and substrate saccharification in BMP tests, which not necessarily translates to high methane yields as compared to alkaline pretreatment alone [56], suggesting to re-think the role of enzymes in multiple-pretreatment settings. The application of natural endogenous hydrolases such as amylase and protease from fermentation sludge for pretreatment of wastewater sludge resulted in improved sludge solubilization and acidification regarding the COD and VFA upturn [57], whereas a positive effect on anaerobic biodegradability, hydrolysis, digestion rates as well as maintaining a healthy microbial population were not indicated [58]. However, enzyme treatment can improve the economic production of biogas from agricultural residues, municipal solid and animal wastes by enhancing the fluidity of fibrous feedstock mixtures [59], solubilization and deflocculation of wastewater and sewage sludge biomass towards anaerobic digestibility [60][61][62].…”

Section: Enzyme Tests and Applicationsmentioning

confidence: 99%

Microbiology and Molecular Biology Tools for Biogas Process Analysis, Diagnosis and Control

Lebuhn

Weiß

Munk

et al. 2015

Biogas Science and Technology

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Many biotechnological processes such as biogas production or defined biotransformations are carried out by microorganisms or tightly cooperating microbial communities. Process breakdown is the maximum credible accident for the operator. Any time savings that can be provided by suitable early-warning systems and allow for specific countermeasures are of great value. Process disturbance, frequently due to nutritional shortcomings, malfunction or operational deficits, is evidenced conventionally by process chemistry parameters. However, knowledge on systems microbiology and its function has essentially increased in the last two decades, and molecular biology tools, most of which are directed against nucleic acids, have been developed to analyze and diagnose the process. Some of these systems have been shown to indicate changes of the process status considerably earlier than the conventionally applied process chemistry parameters. This is reasonable because the triggering catalyst is determined, activity changes of the microbes that perform the reaction. These molecular biology tools have thus the potential to add to and improve the established process diagnosis system. This chapter is dealing with the actual state of the art of biogas process analysis in practice, and introduces molecular biology tools that have been shown to be of particular value in complementing the current systems of process monitoring and diagnosis, with emphasis on nucleic acid targeted molecular biology systems.

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“…Recent studies have focused on improving the solubilization of sludge (YU et al, 2013), focusing on enzyme mechanisms in terms of solubilization of extracellular polymeric substances. DONOSO-BRAVO & FDZ-POLANCO (2013) used a first-order model to obtain some kinetic parameters and therefore the preliminary basic design of a continuous process, by stimulating methane production through the addition of lipase to anaerobic treatments of sewage sludge and grease trap.…”

Section: Introductionmentioning

confidence: 99%

Cellulase effect on anaerobic digestion of maize silage under discontinuous operation

et al. 2015

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This paper studied the effect of adding an enzyme ( ellulose) on anaerobic digestion of maize silage. We compared materials at chopping lengths of 8 mm (MSL), 4mm (MSS) and natural size (Ms) under a mesophilic and discontinuous operation (batch process). Hence, we found the process to be significantly influenced by particle size. Moreover, the ellulose addition did not significantly impact biogas production after a 35-day digestion period. Ms and MSS displayed an improved response to all variables when compared with MSL and MSL+C, with significant differences. Studies on the refractory fraction at infinite time (R 0 ) have demonstrated that the lowest values correspond to Ms and MSS (0.122 and 0.155, respectively

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Effect of endogenous hydrolytic enzymes pretreatment on the anaerobic digestion of sludge

Cited by 161 publications

References 16 publications

Screening pretreatment methods to enhance thermophilic anaerobic digestion of pulp and paper mill wastewater treatment secondary sludge

Screening pretreatment methods to enhance thermophilic anaerobic digestion of pulp and paper mill wastewater treatment secondary sludge

Microbiology and Molecular Biology Tools for Biogas Process Analysis, Diagnosis and Control

Cellulase effect on anaerobic digestion of maize silage under discontinuous operation

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