H_(2)O_(2)&Fe^(2+)预处理对天然有机物膜污染行为的影响机制  

Influencing mechanism of H_(2)O_(2) & Fe^(2+) pre-treatment on natural organic matter fouling behavior of membranes

作　　者：苗瑞 田曼琳 杨祎凡 米悦 王磊 黄丹曦 MIAO Rui;TIAN Man-lin;YANG Yi-fan;MI Yue;WANG Lei;HUANG Dan-xi(Key Laboratory of Northwest Water Resource,Environment and Ecology,Key Laboratory of Membrane Separation of Shaanxi Province,School of Environmental and Municipal Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;Research Institute of Membrane Seperation Technology of Shaanxi Province,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,西北水资源与环境生态教育部重点实验室,陕西省膜分离重点实验室,陕西西安710055 [2]陕西省膜分离技术研究院,陕西西安710055

出　　处：《中国环境科学》2024年第12期6691-6697,共7页China Environmental Science

基　　金：国家自然科学基金面上项目(52070150,52370049);陕西省国际合作普通项目(2022KW-24);陕西高校青年创新团队资助项目(2023-2026)。

摘　　要：选用腐殖酸(HA)代表天然有机物,考察微量H_(2)O_(2)&Fe^(2+)预处理对膜污染的减缓机理及减缓效果关键影响因素.结果发现,无需提供额外酸性条件,投加100μmol/L的Fe^(2+)和H_(2)O_(2)反应20min后,膜通量衰减率可从83%降低到20%,通量恢复率从26%增大到100%,且膜污染减缓能力随反应时间和H_(2)O_(2)&Fe^(2+)投加量的增大在持续增大,远优于同等剂量H_(2)O_(2)、Fe^(2+)或Fe^(3+)的膜污染减缓能力.究其原因,主要因为H_(2)O_(2)&Fe^(2+)可诱导HA产生羧酸,进而触发Fenton反应.Fenton过程的氧化和混凝协同作用,促使HA分子间团聚形成大尺寸絮体并削弱HA在膜面作用力,导致污染物在膜面的吸附累积速率降低,且形成松散的污染层,最终伴随着膜污染的大幅度减缓.Membrane fouling caused by natural organic matter(NOM) is a significant challenge that impedes the efficient and cost-effective operation of ultrafiltration(UF) systems.This study investigates the effectiveness of a trace-level pre-treatment using H_(2)O_(2) and Fe^(2+) to mitigate membrane fouling induced by humic acid(HA),a model NOM.The results demonstrate that the addition of 100μmol/L Fe^(2+) and H_(2)O_(2),followed by a 20-minute reaction,significantly reduces flux decline from 83% to 20% and enhances flux recovery from 26% to 100%,without the need for acidic conditions.The fouling reduction capability increases with both the duration of the reaction and the dosages of H_(2)O_(2) and Fe^(2+),surpassing the individual effects of H_(2)O_(2),Fe^(2+),or Fe^(3+) alone.This improvement is attributed to the generation of carboxyl groups in HA,which triggers a Fenton reaction.The combined oxidation and coagulation processes promote HA aggregation into larger flocs,diminishing HA adhesion to the membrane surface,and ultimately reducing the rate of fouling.The resulting fouling layer is less dense and more easily removable,leading to sustained membrane performance.These findings provide valuable insights into novel strategies for mitigating UF membrane fouling,offering both theoretical and practical contributions to membrane filtration technology.

关 键 词：天然有机物 超滤膜污染 H_(2)O_(2)&Fe^(2+)预处理 界面作用力 污染物尺寸 

分 类 号：X703[环境科学与工程—环境工程]