低电压模式下茶多酚增强电芬顿提高污泥脱水性能的作用机制  

The enhancement of sludge dewaterability by tea polyphenols assisted electro-Fenton under low voltage

作　　者：谷麟[1] 曹孝 王欣[1] 宋小毛 许智华[1] 徐苏云[1] 蔡苗 GU Lin;CAO Xiao;WANG Xin;SONG Xiaomao;XU Zhihua;XU Suyun;CAI Miao(School of Environment and Architecture,University of Shanghai for Science and Technology,Shanghai 200093;Hainan Pujin Environmental Technology Co.,Ltd.,Haikou 570100;Haikou Engineering Technology Research Center of Soild Waste Treatment&Disposal and Solid Remediation,Haikou 570100)

机构地区：[1]上海理工大学环境与建筑学院,上海200093 [2]海南墣锦环境科技股份有限公司,海口570100 [3]海口市固废处理处置与土壤修复工程技术研究中心,海口570100

出　　处：《环境科学学报》2024年第10期308-321,共14页Acta Scientiae Circumstantiae

摘　　要：电芬顿法耦合电化学氧化与电絮凝,是近年来在传统Fenton氧化技术上发展起来的一种新型污泥预处理与脱水技术.然而,较高的操作电压易导致电极副反应加剧,阳极区释放的Fe2+快速累积并争夺羟基自由基,使系统电流效率下降、体系能耗升高,因此,解决低电压电芬顿预处理污泥的关键是改善Fe3+在多相体系中的高效还原.茶多酚(TP)是一类环境友好、含高活性酚羟基结构的多元酚的混合物,兼具螯合性与还原性,本文使用茶多酚为助剂,研究其作为中间体在低电压模式下对电芬顿提高污泥脱水性能的增强作用及机制.结果表明,当以铁板为阳极,槽电压为8 V,初始pH为4,并分别向体系中投加1.0 mL·L^(-1)的H2O2和30 mg·g^(-1)TS的TP时,处理15 min后的污泥毛细吸水时间(CST)和含水率(WC)可分别降至最低,分别达到25.7 s和59.3%,相比未加TP时在最佳条件下节省能耗17.5%.一方面,茶多酚可以增加低电压下体系中溶解性铁的含量,通过Fe-π键促进Fe3+/Fe2+循环,高效还原H2O2并持续性产生·OH,破坏污泥絮体结构和降解胞外聚合物;另一方面,茶多酚与水分子竞争EPS中蛋白质的亲水位点,通过改变蛋白质的二级结构和暴露蛋白中的疏水位点,降低水分羟基同蛋白质侧链的结合,使污泥结合水降低,絮体颗粒沉降,污泥脱水性能得以提升.The electro-fenton,integrated with electrochemical oxidation and electrocoagulation,has advanced the traditional Fenton technique and emerged as a novel sludge pretreatment and dewatering technology in recent years.However,high applied voltages tend to exacerbate electrode side reactions,with the rapid accumulation of Fe2+released in the anode competing for hydroxyl radicals,leading to a decrease in the system's current efficiency and an increase in energy consumption.Therefore,addressing the low-voltage electro-Fenton pretreatment of sludge may be accomplished by improving the efficient reduction of Fe3+ions in multiphase systems.Tea polyphenols(TP),a mixture of polyphenols with high activity phenolic hydroxyl structures,are environmentally friendly and possess both chelating and reducing properties.This study utilizes tea polyphenols as an adjunct to investigate their enhancing effect on sludge dewaterability under low voltage conditions in the electro-Fenton process.The findings indicate that when using an iron plate as the anode and maintaining a cell voltage of 8 V,an initial pH of 4,and the addition of 1.0 mL·L^(-1) H2O2 and 30 mg·g^(-1) TS of TP,the Capillary Sunction Time(CST)and Water Content(WC)of the sludge are minimized after 15 min,reaching 25.7 s and 59.3%,respectively.This results in a 17.5%reduction in energy consumption compared to the optimal conditions without the addition of TP.On one hand,TP can increase the content of dissolved iron under low voltage,promoting the Fe3+/Fe2+cycle through Fe-πbonds,,thereby disrupting sludge flocs and degrading EPS.On the other hand,TPs compete with water molecules for the hydrophilic sites in the EPS proteins,altering the secondary structure of proteins and exposing hydrophobic sites within them.This reduces the binding between water hydroxyl groups and protein side chains,decreasing the bound water in sludge, facilitating floc particle settlement, and thereby enhancing sludge dewaterability.

关 键 词：茶多酚 电芬顿 EPS 污泥脱水 

分 类 号：X703[环境科学与工程—环境工程]