title: Chelating polymer modified P84 nanofiltration (NF) hollow fiber membranes for high efficient heavy metal removal.
abstract: High performance nanofiltration (NF) membranes for heavy metal removal have been molecularly designed by adsorption of chelating polymers containing negatively charged functional groups such as poly (acrylic acid-co-maleic acid) (PAM), poly (acrylic acid) (PAA) and poly (dimethylamine-co-epichlorohydrin-co-ethylenediamine) (PDMED) on the positively charged polyethyleneimine (PEI) cross-linked P84 hollow fiber substrates. Not only do these chelating polymers change the membrane surface charge and pore size, but also provide an extra mean to remove heavy metal ions through adsorption in addition to traditional steric effect and Donnan exclusion. The adsorbed membranes have comparable water permeability and superior rejections to heavy metals, for instance, Pb(NO3)2, CuSO4, NiCl2, CdCl2, ZnCl2, Na2Cr2O7 and Na2HAsO4, with rejections higher than 98%. The membranes also display excellent rejections to mixed ions with rejections more than 99%. The newly developed membranes show reasonably stability during 60-h tests as well as multiple washes.
authors.affiliation: Department of Chemical & Biomolecular Engineering, National University of Singapore, 10 Kent Ridge, Crescent, Singapore 119260, Singapore.
authors.forename: Jie
authors.initials: J
authors.lastname: Gao
authors.affiliation: Department of Chemical & Biomolecular Engineering, National University of Singapore, 10 Kent Ridge, Crescent, Singapore 119260, Singapore.
authors.forename: Shi-Peng
authors.initials: SP
authors.lastname: Sun
authors.affiliation: Department of Chemical & Biomolecular Engineering, National University of Singapore, 10 Kent Ridge, Crescent, Singapore 119260, Singapore.
authors.forename: Wen-Ping
authors.initials: WP
authors.lastname: Zhu
authors.affiliation: Department of Chemical & Biomolecular Engineering, National University of Singapore, 10 Kent Ridge, Crescent, Singapore 119260, Singapore. Electronic address: chencts@nus.edu.sg.
authors.forename: Tai-Shung
authors.initials: TS
authors.lastname: Chung
mesh_terms: D000327:Adsorption; D002614:Chelating Agents / Q000737:chemistry*; D019216:Metals, Heavy / Q000737:chemistry*; D010539:Permeability; D011094:Polyethyleneimine / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D014462:Ultrafiltration / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D002614:Chelating Agents; D019216:Metals, Heavy; D011108:Polymers; D014874:Water Pollutants, Chemical; D011094:Polyethyleneimine
keywords: Cheating polymer; Heavy metal ions; Hollow fiber membrane; Hyperbranched polyethyleneimine; Nanofiltration; P84 polyimide