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
• 来源期刊: 环境科学学报（英文版）
• 年，卷（期）: 2022,（3）
• 页码范围: 26-39
• 页数: 14页
• 语种: 英文

摘要

Cationic hydrogels have received great attention to control eutrophication and recycle phos-phate.In this study,a type of La(OH)3 loaded magnetic MAPTAC-based cationic hydro-gel (La(OH)3@MMCH) was developed as a potential adsorbent for enhanced phosphate re-moval from aqueous environment.La(OH)3@MMCH exhibited high adsorption capacity of 105.72±-5.99 mg P/g,and reached equilibrium within 2 hn La(OH)3@MMCH could perform ef-fectively in a wide pH range from 3.0 to 9.0 and in the presence of coexisting ions (including SO42-,Cl-,NO3-,HCO3-,SiO44-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 MMGH could produce the enhanced Donnan membrane effect to pre-perrneate phosphate.Furthermore,the bifunctional structure of La(OH)3@MMCH en-abled 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.