Phosphate removal by a La(OH)_(3) loaded magnetic MAPTAC-based cationic hydrogel:Enhanced surface charge density and Donnan membrane effect  

作　　者：Yanqing Zhou Yili Wang Shuoxun Dong Haotian Hao Junyi Li Chenyang Liu Xiaolin Li Yao Tong 

机构地区：[1]College of Environmental Science and Engineering,Beijing Key Lab for Source Control Technology of Water Pollution,Beijing Forestry University,Beijing 100083,China [2]Center for Water and Ecology,State Key Joint Laboratory of Environment Simulation and Pollution Control,School of Environment,Tsinghua University,Beijing 100083,China [3]State Key Laboratory of Environmental Aquatic Chemistry,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China

出　　处：《Journal of Environmental Sciences》2022年第3期26-39,共14页环境科学学报（英文版）

基　　金：This work was supported by the Beijing Municipal Science and Technology Project(No.Z181100005518007);the National Key Research and Development Program of China(No.2017YFC0505303);the National Natural Science Foundation of China(Nos.51978054 and 51678053).

摘　　要：Cationic hydrogels have received great attention to control eutrophication and recycle phosphate.In this study,a type of La(OH)_(3) loaded magnetic MAPTAC-based cationic hydrogel(La(OH)_(3)@MMCH)was developed as a potential adsorbent for enhanced phosphate removal from aqueous environment.La(OH)_(3)@MMCH exhibited high adsorption capacity of 105.72±5.99 mg P/g,and reached equilibrium within 2 hr.La(OH)_(3)@MMCH could perform effectively in a wide pH range from 3.0 to 9.0 and in the presence of coexisting ions(including SO_(4)^(2-),Cl^(-),NO_(3)^(-),HCO_(3)^(-),SiO_(4)^(4-) and HA).The adsorption-desorption experiment indicated that La(OH)_(3)@MMCH could be easily regenerated by using NaOH-NaCl as the desorption agent,and 73.3%adsorption capacity remained after five cycles.Moreover,La(OH)_(3)@MMCH was employed to treat surface water with phosphate concentration of 1.90 mg/L and showed great removal efficiency of 95.21%.Actually,MMCH showed high surface charge density of 34.38-59.38 meq/kg in the pH range from 3.0 to 11.0 and great swelling ratio of 3014.57%within 24 h,indicating that MMCH could produce the enhanced Donnan membrane effect to pre-permeate phosphate.Furthermore,the bifunctional structure of La(OH)_(3)@MMCH enabled it to capture phosphate through electrostatic attraction and ligand exchange.All the results prove that La(OH)_(3)@MMCH is a promising adsorbent for eutrophication control and phosphate recovery.

关 键 词：Cationic hydrogel La(0H)_(3) Phosphate adsorption Enhanced Donnan membrane effect 

分 类 号：TQ427.26[化学工程] X52[环境科学与工程—环境工程]