title: [Optimization for phosphorous removal in thickening and dewatering sludge water by polyaluminum chloride].
abstract: Based on the comparison of phosphorous removal in sludge water and its supernatant by polyaluminum chloride (PAC), separate and combined effects of Al/P mole ratio, pH and mixing speed (MS) on phosphorus removal by PAC for the supernatant of thickening and dewatering sludge water were analyzed by the response surface methodology (RSM), and kinetics of phosphorous removal by PAC was also investigated. The results showed that direct addition of PAC into sludge water deteriorated its settling characteristics, and suspended solids in the sludge water could decrease the phosphorus removal efficiency. The RSM analysis results demonstrated that the effect of individual operation parameter on phosphorus removal was followed as the order of Al/P > pH > MS, and the optimal process parameters with phosphorus removal efficiency of 97.8% were Al/P = 2.49, pH = 8.3 and MS 398 r x min(-1), respectively. The verification experiment showed that the RSM model was valid and effective. Kinetic analysis illustrated that phosphorus removal by PAC was divided into two stages, a chemical precipitation and rapid adsorption stage, followed by a chemical precipitation stage that conformed to the second-order kinetics.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhou
authors.forename: Da-Long
authors.initials: DL
authors.lastname: Hu
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Qiao
authors.forename: Guan-Han
authors.initials: GH
authors.lastname: Chen
authors.forename: Ling-Yan
authors.initials: LY
authors.lastname: Jiang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.forename: Sui-Hai
authors.initials: SH
authors.lastname: Mai
mesh_terms: D000327:Adsorption; D000536:Aluminum Hydroxide / Q000737:chemistry*; D011232:Chemical Precipitation; D007700:Kinetics; D010758:Phosphorus / Q000032:analysis*; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D012722:Sewage; D014867:Water; C016213:aluminum oxychloride; D010758:Phosphorus; D000536:Aluminum Hydroxide