电絮凝耦合DSA或过氧化氢强化污泥脱水性能的比较与机理分析  

Comparison and mechanism of electric flocculation coupled with DSA or hydrogen peroxide to enhance sludge dewatering performance

作　　者：陈亚 赵敏 章萍萍 张道方[1] 杨成 俞海祥 陆俊洋 谷麟[1] CHEN Ya;ZHAO Min;ZHANG Pingping;ZHANG Daofang;YANG Cheng;YU Haixiang;LU Junyang;GU Lin(School of Environment and Architecture,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学环境与建筑学院,上海200093

出　　处：《环境工程学报》2023年第1期218-234,共17页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(51408358)。

摘　　要：为解决电絮凝法调理污泥期间电场无法有效破解污泥絮体、改善污泥脱水问题,分别将电絮凝与尺寸稳定阳极(DSA,Dimensionally-stable anodes)电极、H_(2)O_(2)进行耦合,比较和分析2种耦合工艺对污泥过滤性能、絮体破解程度、胞外聚合物(EPS)组分改变和污泥脱水性能的差异。结果表明,电絮凝耦合H_(2)O_(2)形成的间接氧化体系中,由于电致·OH在非均相体系中能无选择性地破坏污泥絮体、破解污泥细胞并降解胞外聚合物(EPS),从而促使阳极释放的铁离子通过吸附架桥、网捕等作用与絮体碎片和EPS片段重聚并沉淀,使15 min内污泥毛细吸水时间(CST)和污泥含水率(MC)分别下降了73.9%和31.4%;然而电絮凝耦合DSA直接氧化法同期的污泥CST和MC仅分别下降了64.9%和26.4%。此外,间接氧化法可以同时降解松散结合层(LB-EPS)和紧密结合层(TB-EPS),破坏EPS蛋白质亲水基团与水的作用力,并改善传统电化学法主要降解LB-EPS的不足,实现了提高电化学方法在同步污泥破解与沉降脱水方面的双重效能。本研究结果可为电化学预处理改善污泥脱水提供参考。Aiming to solve the problems that traditional electric field cannot effectively crack the sludge flocs and improve the sludge dewatering during sludge conditioning by electric flocculation, coupling electric flocculation with DSA(Dimensionally Stable Anodes) electrode and H_(2)O_(2)was used and their effects were compared. The differences was evaluated in terms of sludge filtration performance, floc breaking degree,changes in the composition of extracellular polymers(EPS). Results showed that in indirect oxidation systems(electro-coagulation with H_(2)O_(2)), the electro-generated ·OH could selectively destroy the sludge flocs, break sludge cells and degrade the extracellular polymer(EPS), causing the dissolution and degradation of EPS. The system could also promote the quick release of ferric ions and generate polyferric substance, enhancing the reunion and sediment of EPS fragments. In this circumstance, the CST and MC of sewage sludge could be decreased by 73.9% and 31.4% respectively within 15 min. However, the sludge CST and MC with DSA coupled direct oxidation just realized 64.9% and 26.4% reduction. The indirect oxidation could degrade both loosely bound layer(LB-EPS) and tightly bound(TB-EPS), destroying the interactions between hydrophilic groups of EPS protein and water and thus improving the drawbacks of direct oxidation. The results of this study would provide a reference for electrochemical pretreatment to improve sludge dewatering.

关 键 词：电絮凝 直接氧化 间接氧化 污泥脱水 胞外聚合物 

分 类 号：X703[环境科学与工程—环境工程]