title: Influence of pH on heavy metal speciation and removal from wastewater using micellar-enhanced ultrafiltration.
abstract: pH plays an important role in heavy metal removal during micellar-enhanced ultrafiltration (MEUF). In the present work, the influence of pH on heavy metal speciation and removal from wastewater by MEUF was investigated using an anionic surfactant (sodium dodecyl sulfate, SDS) and a hydrophilic membrane (polyether sulfone). Experiments were performed with pH values in the range of 1-12. Metal ion removal efficiency (R) was used to assess the effects of the MEUF process. Results showed that better removal rate of copper and cadmium was achieved at high pH values (pH > 3) with SDS feed concentration of 8 mM, while the optimal pH range was 3-10 for zinc and lead. The corresponding efficiencies for heavy metal removal decreased with the increasing feed concentration of metal ions under the pH conditions of 1-12. Furthermore, the heavy metal ion removal rate (50 mg/L) followed the order of Pb2+> Cd2+> Zn2+> Cu2+. These results showed that pH is a key parameter in metal ion speciation and removal during MEUF.
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China. Electronic address: huangjinhui_59@163.com.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Huang
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Yuan
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China. Electronic address: zgming@hnu.edu.cn.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zeng
authors.affiliation: Department of Bioengineering and Environmental Science, Changsha University, Changsha 410003, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Li
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Gu
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China.
authors.forename: Lixiu
authors.initials: L
authors.lastname: Shi
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China.
authors.forename: Wenchu
authors.initials: W
authors.lastname: Liu
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China.
authors.forename: Yahui
authors.initials: Y
authors.lastname: Shi
mesh_terms: D002104:Cadmium / Q000302:isolation & purification; D003300:Copper / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000302:isolation & purification*; D008823:Micelles; D012967:Sodium Dodecyl Sulfate; D013501:Surface-Active Agents / Q000737:chemistry*; D014462:Ultrafiltration / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D015032:Zinc / Q000302:isolation & purification
chemical_list: D019216:Metals, Heavy; D008823:Micelles; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D002104:Cadmium; D012967:Sodium Dodecyl Sulfate; D003300:Copper; D015032:Zinc
keywords: Heavy metal speciation; Micellar-enhanced ultrafiltration; Removal efficiency; pH