title: The effect of calcium on the treatment of fresh leachate in an expanded granular sludge bed bioreactor.
abstract: This research investigated the calcium effect on the anaerobic treatment of fresh leachate in an expanded granular sludge bed (EGSB) bioreactor under mesophilic conditions. The observations show that the bioreactor, inoculated with anaerobic granular sludge, can be started up only in about 40 days for the treatment of calcium-containing fresh leachate with chemical oxygen demand (COD) removal efficiency above 90% and organic loading rate up to 72.84 kg COD/m(3) day. The calcium accumulation onto the granules was monotonically related to the calcium concentration, accounting for 17-18 wt.% of Ca in the suspended solid in the form of calcium carbonate, phosphates/phosphonates and carboxylates. The mineral formation significantly increased the granule settling velocity (by ∼ 50%) and the suspended solid concentration (by ∼ 100%). However, the effect of calcium precipitation on the specific methanogenic activity and the CH(4) production rate was complex, first positive during the start-up but later on negative.
authors.affiliation: Department of Environmental Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, PR China.
authors.forename: Jianyong
authors.initials: J
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Hu
authors.forename: Jiangping
authors.initials: J
authors.lastname: Zhong
authors.forename: Jinghuan
authors.initials: J
authors.lastname: Luo
authors.forename: Aihua
authors.initials: A
authors.lastname: Zhao
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Ruijing
authors.initials: R
authors.lastname: Hong
authors.forename: Guangren
authors.initials: G
authors.lastname: Qian
authors.forename: Zhi Ping
authors.initials: ZP
authors.lastname: Xu
mesh_terms: D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D002118:Calcium / Q000737:chemistry*; D011232:Chemical Precipitation; D008697:Methane / Q000032:analysis; D009584:Nitrogen / Q000302:isolation & purification; D010758:Phosphorus / Q000302:isolation & purification; D012722:Sewage / Q000737:chemistry*; D014835:Volatilization; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000295:instrumentation*
chemical_list: D012722:Sewage; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen; D008697:Methane; D002118:Calcium