Treatment of phosphate-containing oily wastewater by coagulation and microfiltration  

作　　者：ZHANG Jin SUN Yu-xin HUANG Zhi-feng LIU Xing-qin MENG Guang-yao 

机构地区：[1]Department of Materials of Science and Engineering, University of Science and Technology of China Hefei 230026,China [2]School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, China [3]National Key Laboratory of Transient Physics, Nanjing 210094, China [4]Great Wall New Century Membrane Technology Corporation, Hefei 230601, China

出　　处：《Journal of Environmental Sciences》2006年第4期629-633,共5页环境科学学报（英文版）

基　　金：TheMinistryofScienceandTechnologyofChina(No.2003CB615700);theNationalNaturalScienceFoundationofChina(No.10402041)andtheNaturalScienceFoundationofEducationalDepartmentofAnhuiProvince(No.2005KJ103)

摘　　要：The oily wastewater generated from pretreatment unit of electrocoating industry contains oils, phosphate, organic solvents, and surfactants. In order to improve the removal efficiencies of phosphate and oils, to mitigate the membrane fouling, coagulation for ceramic membrane microfiltration of oily wastewater was performed. The results of filtration tests show that the membrane fouling decreased and the permeate flux and quality increased with coagulation as pretreatment. At the coagulant Ca （OH）2 dosage of 900 mg/L, the removal efficiency of phosphate was increased from 46.4% without coagulation to 99.6%; the removal of COD and oils were 97.0% and 99.8%, respectively. And the permeate flux was about 70% greater than that when Ca（OH）2 was not used. The permeate obtained from coagulation and microfiltration can be reused as make-up water, and the recommended operation conditions for pilot and industrial application are transmembrane pressure of 0.10 MPa and cross-flow velocity of 5 m/s. The comparison results show that 0.2 μm ZrO2 microfilter with coagulation could be used to perform the filtration rather than conventional ultrafilter, with very substantial gain in flux and removal efficiency of phosphate.The oily wastewater generated from pretreatment unit of electrocoating industry contains oils, phosphate, organic solvents, and surfactants. In order to improve the removal efficiencies of phosphate and oils, to mitigate the membrane fouling, coagulation for ceramic membrane microfiltration of oily wastewater was performed. The results of filtration tests show that the membrane fouling decreased and the permeate flux and quality increased with coagulation as pretreatment. At the coagulant Ca （OH）2 dosage of 900 mg/L, the removal efficiency of phosphate was increased from 46.4% without coagulation to 99.6%; the removal of COD and oils were 97.0% and 99.8%, respectively. And the permeate flux was about 70% greater than that when Ca（OH）2 was not used. The permeate obtained from coagulation and microfiltration can be reused as make-up water, and the recommended operation conditions for pilot and industrial application are transmembrane pressure of 0.10 MPa and cross-flow velocity of 5 m/s. The comparison results show that 0.2 μm ZrO2 microfilter with coagulation could be used to perform the filtration rather than conventional ultrafilter, with very substantial gain in flux and removal efficiency of phosphate.

关 键 词：ceramic membrane crossflow microfiltration COAGULATION phosphate removal fouling mitigation phosphate-containing oily wastewater 

分 类 号：X703[环境科学与工程—环境工程]