title: Inhibitory effect of high calcium concentration on municipal solid waste leachate treatment by the activated sludge process.
abstract: This research focused on the inhibitory effects of Ca on the aerobic biological treatment of landfill leachate containing extremely high Ca concentrations. When the Ca concentration in leachate to be treated was more than 4500 mg l-1, the total organic carbon removal rate was significantly reduced and the processing time to achieve the same removal efficiency was 1.4 times that in the control treatment without added Ca. In contrast, the total nitrogen and ammonia nitrogen (NH4+-N) removal efficiencies were positively related to the Ca concentration, increasing from 65.2% to 81.2% and from 69.2% to 83.7%, respectively, when the dosage of added Ca increased from zero to 8000 mg l-1. During aerobic treatment, the reductions of solution Ca concentration were in the range of 1003-2274 mg l-1and were matched with increases in the Ca content in the residual sludge. The inhibition threshold of Ca in the leachate treated by the activated sludge process appeared to be 4500 mg l-1, which could be realized by controlling the influent Ca concentration and using an appropriate sludge return ratio in the activated sludge process.
authors.affiliation: 1 State Key Laboratory of Pollution Control & Resource Reuse, Tongji University, P.R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xia
authors.affiliation: 2 Institute of Waste Treatment and Reclamation, Tongji University, P.R. China.|3 Center for the Technology Research and Training on Household Waste in Small Towns & Rural Area, Ministry of Housing and Urban-Rural Development of P.R. China, P.R. China.
authors.forename: Pin Jing
authors.initials: PJ
authors.lastname: He
authors.affiliation: 1 State Key Laboratory of Pollution Control & Resource Reuse, Tongji University, P.R. China.
authors.forename: Hong Xia
authors.initials: HX
authors.lastname: Pu
authors.affiliation: 4 State Key Laboratory of Pollution Control & Resource Reuse, Institute of Waste Treatment and Reclamation, P.R. China.
authors.forename: Fan
authors.initials: F
authors.lastname: Lü
authors.affiliation: 5 Institute of Waste Treatment and Reclamation, Tongji University, P.R. China.
authors.forename: Li Ming
authors.initials: LM
authors.lastname: Shao
authors.affiliation: 6 State Key Laboratory of Pollution Control & Resource Reuse, Institute of Waste Treatment and Reclamation, Tongji University, P.R. China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
mesh_terms: D019149:Bioreactors; D002118:Calcium; D009584:Nitrogen; D012722:Sewage; D062611:Solid Waste; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical
chemical_list: D012722:Sewage; D062611:Solid Waste; D014874:Water Pollutants, Chemical; D009584:Nitrogen; D002118:Calcium
keywords: High Ca concentration; activated sludge; inhibition threshold; inhibitory effect; leachate treatment