Prediction of methane yield at optimum pH for anaerobic digestion of organic fraction of municipal solid waste

• Published in: Bioresource technology Vol. 99; no. 4; pp. 882 - 888
• Main Authors: Liu, Cun-fang, Yuan, Xing-zhong, Zeng, Guang-ming, Li, Wen-wei, Li, Jing
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-03-2008; [New York, NY]: Elsevier Ltd; Elsevier
• Subjects: Anaerobic batch reactor; Anaerobic process; Applied sciences; Bacteria, Anaerobic - metabolism; Biological and medical sciences; Biological treatment of sewage sludges and wastes; Bioreactors; Bioreactors - microbiology; Biotechnology; Cities; Computer Simulation; Environment and pollution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Industrial applications and implications. Economical aspects; Mathematical model; Methane - metabolism; Methane yield at optimum pH; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; Models, Biological; Municipal solid waste; Organic Chemicals - isolation & purification; Organic Chemicals - metabolism; Pollution; Refuse Disposal - methods; Various methods and equipments; Wastes; Water Pollutants, Chemical - isolation & purification; Water Pollutants, Chemical - metabolism; Anaerobic batch reactor; Anaerobic process; Mathematical model; Methane yield at optimum pH; Municipal solid waste; Methane; Organic matter; Urban waste; Prediction; Anaerobic digestion; Bioreactor; Anaerobe; Batch process; Solid waste; Anaerobic fermentation; Reactor; Optimum pH
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2007.01.013

A concept of methane yield at optimum pH was advanced and subsequently a mathematical model that simulates the optimal pH of a batch process for anaerobic digestion of organic fraction of municipal solid waste (MSW) was developed and validated. The model was developed on the basis of the microbial growth kinetics and was divided into three processes: hydrolysis of substrates by hydrolytic bacteria, consumption of soluble substrate by acidogenic bacteria, and finally consumption of acetate and methane generated by methanogenic bacteria. Material balance and liquid phase equilibrium chemistry were used in this study. A series of experiments were conducted to validate the model. The model simulation results agreed reasonably with experimental data in different temperatures and total solid (TS) concentrations under uncontrolled pH. A computer circulation program was used to predict the optimal pH in different conditions. Experiments in different temperatures and TS were run under optimal pH which predicted by the model. The model was succeeded in increasing the methane production and the cumulative methane production had an average increment about 35% in optimal pH of different temperatures and TS.