title: A highly efficient polyampholyte hydrogel sorbent based fixed-bed process for heavy metal removal in actual industrial effluent.
abstract: High sorption capacity, high sorption rate, and fast separation and regeneration for qualified sorbents used in removing heavy metals from wastewater are urgently needed. In this study, a polyampholyte hydrogel was well designed and prepared via a simple radical polymerization procedure. Due to the remarkable mechanical strength, the three-dimensional polyampholyte hydrogel could be fast separated, easily regenerated and highly reused. The sorption capacities were as high as 216.1 mg/g for Pb(II) and 153.8 mg/g for Cd(II) owing to the existence of the large number of active groups. The adsorption could be conducted in a wide pH range of 3-6 and the equilibrium fast reached in 30 min due to its excellent water penetration for highly accessible to metal ions. The fixed-bed column sorption results indicated that the polyampholyte hydrogel was particularly effective in removing Pb(II) and Cd(II) from actual industrial effluent to meet the regulatory requirements. The treatment volumes of actual smelting effluent using one fixed bed column were as high as 684 bed volumes (BV) (7736 mL) for Pb(II) and 200 BV (2262 mL) for Cd(II). Furthermore, the treatment volumes of actual smelting effluent using tandem three columns reached 924 BV (31,351 mL) for Pb(II) and 250 BV (8483 mL) for Cd(II), producing only 4 BV (136 mL) eluent. Compared with the traditional high density slurry (HDS) process with large amount of sludge, the proposed process would be expected to produce only a small amount of sludge. When the treatment volume was controlled below 209.3 BV (7103 mL), all metal ions in the actual industrial effluent could be effectively removed (<0.01 mg/L). This wok develops a highly practical process based on polyampholyte hydrogel sorbents for the removal of heavy metal ions from practical wastewater.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, PR China.
authors.forename: Guiyin
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Jinming
authors.initials: J
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, PR China. Electronic address: chem_cbliu@hnu.edu.cn.
authors.forename: Chengbin
authors.initials: C
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chu
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Jianhong
authors.initials: J
authors.lastname: Ma
authors.affiliation: College of Materials Science and Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, PR China.
authors.forename: Zebing
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, PR China. Electronic address: sllou@hnu.edu.cn.
authors.forename: Shenglian
authors.initials: S
authors.lastname: Luo
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D007220:Industrial Waste; D007854:Lead / Q000737:chemistry*; D008669:Metallurgy; D019216:Metals, Heavy / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry
chemical_list: D002104:Cadmium; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007220:Industrial Waste; D007854:Lead; D019216:Metals, Heavy; D012722:Sewage; D062065:Wastewater
keywords: Actual wastewater; Fixed-bed process; Heavy metal removal; Polyampholyte hydrogel; Treatment capacity