title: Improved methane production from waste activated sludge with low organic content by alkaline pretreatment at pH 10.
abstract: Sludge with low organic content always results in an unsatisfactory performance, even failure of anaerobic digestion. The alkaline pretreatment effect on anaerobic digestion of sludge with low organic content has seldom been studied although it gives many benefits for sludge with high organic content. In this study the influence of alkaline pretreatment (pH 10, an effective alkaline pH) on the solubilization and methane production from waste activated sludge (WAS) with low organic content was investigated. Results from biochemical methane potential (BMP) experiments showed that anaerobic biodegradability of WAS was greatly improved by alkaline pretreatment at pH 10. Methane production from the current WAS under conditions of pretreatment time 4 h and digestion time 15 d was 139.6 mL/g VS (volatile solids), much higher than that from the unpretreated WAS with digestion time of 20 d (75.2 mL/g VS). Also, the solubilization of WAS was significantly accelerated by alkaline pretreatment. Mechanism exploration indicated that the general activities of anaerobic microorganisms, specific activities of key enzymes and the amounts of methanogens were enhanced by alkaline pretreatment at pH 10, showing good agreement with methane production.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, China E-mail: leiyufeng@tongji.edu.cn; Research and Service Center for Environmental Protection Industry in Yancheng, Jiangsu Province, China.
authors.forename: L Y
authors.initials: LY
authors.lastname: Feng
authors.forename: L Q
authors.initials: LQ
authors.lastname: Yang
authors.forename: L X
authors.initials: LX
authors.lastname: Zhang
authors.forename: H L
authors.initials: HL
authors.lastname: Chen
authors.forename: J
authors.initials: J
authors.lastname: Chen
mesh_terms: D000693:Anaerobiosis; D001421:Bacteria, Anaerobic / Q000378:metabolism; D019149:Bioreactors; D006863:Hydrogen-Ion Concentration; D008697:Methane / Q000138:chemical synthesis*; D009930:Organic Chemicals / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical
chemical_list: D009930:Organic Chemicals; D012722:Sewage; D014874:Water Pollutants, Chemical; D008697:Methane; D010100:Oxygen