title: Inhibition effects of high calcium concentration on anaerobic biological treatment of MSW leachate.
abstract: With the increasing use of municipal solid waste incineration (MSWI) and more stringent limits on landfilling of organic waste, more MSWI bottom ash is being landfilled, and the proportion of inorganic wastes in landfills is increasing, causing the increased Ca concentrations in landfill leachate. In this research, the inhibition effect of Ca concentration on the anaerobic treatment of landfill leachate was studied using a biochemical methane potential experiment. Slight inhibition of methane production occurred when the addition of Ca concentration was less than 2000 mg/L. When the addition of Ca concentration was between 6000 and 8000 mg/L, methane production was significantly reduced (to 29.4-34.8 % of that produced by the BLK reactor), and the lag phase was increased from 8.55 to 16.32 d. Moreover, when the dosage of Ca concentration increased from zero to 8000 mg/L, reductions in solution Ca concentration increased from 929 to 2611 mg/L, and the proportion of Ca in the residual sludge increased from 22.58 to 46.87 %. Based on the results, when the dosage of Ca concentration was less than 4000 mg/L, the formation of Ca precipitates on the surface of sludge appeared to prevent mass transfer and was the dominant reason for the reduction in methane production and sludge biomass. At higher Ca concentrations (6000-8000 mg/L), the severe inhibition of methane production appeared to be caused by the toxic effect of highly concentrated Ca on sludge as well as mass transfer blockage.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, 200092, People's Republic of China.|Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, People's Republic of China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, People's Republic of China.|Center for the Technology Research and Training on Household Waste in Small Towns and Rural Area, Ministry of Housing and Urban-Rural Development of People's Republic of China, Shanghai, 200092, People's Republic of China.
authors.forename: Pin-Jing
authors.initials: PJ
authors.lastname: He
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, 200092, People's Republic of China.|Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, People's Republic of China.
authors.forename: Hong-Xia
authors.initials: HX
authors.lastname: Pu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, 200092, People's Republic of China.
authors.forename: Fan
authors.initials: F
authors.lastname: Lü
authors.affiliation: Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, People's Republic of China.|Center for the Technology Research and Training on Household Waste in Small Towns and Rural Area, Ministry of Housing and Urban-Rural Development of People's Republic of China, Shanghai, 200092, People's Republic of China.
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Shao
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, 200092, People's Republic of China. zhanghua_tj@tongji.edu.cn.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000693:Anaerobiosis; D002118:Calcium / Q000032:analysis*; D060729:Coal Ash / Q000737:chemistry; D017745:Incineration / Q000379:methods*; D008697:Methane / Q000032:analysis; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D062611:Solid Waste / Q000032:analysis*; D064091:Waste Disposal Facilities; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D060729:Coal Ash; D012722:Sewage; D062611:Solid Waste; D014874:Water Pollutants, Chemical; D008697:Methane; D002118:Calcium
keywords: Anaerobic leachate treatment; Biochemical methane potential experiment; CaCO3 precipitations; High Ca concentration; Inhibitory effect; Methane production