锰铈催化膜-臭氧工艺对污水厂二级出水的去除特性

The removal characteristics of pollutants in the secondary effluent by a MnCe-catalytic ceramic membrane-ozonation process

为深入解析锰铈催化膜-臭氧工艺(O_(3)/MnCe-CM)对二级出水中微量污染物和常规污染物的去除特性,以陶瓷膜-臭氧工艺(O_(3)/CM)为对照,研究了锰铈催化膜-臭氧工艺在单独膜过滤、臭氧投加量2.5~5 mg·L^(-1)时,对二级出水中4种典型微量污染物和常规有机物的去除特性。结果表明,与陶瓷膜-臭氧工艺相比,锰铈催化膜-臭氧工艺对阿特拉津、苯并三唑、避蚊胺和西玛津的去除率显著提高,臭氧投加量5 mg·L^(-1)时,锰铈催化膜-臭氧工艺反应动力学常数为陶瓷膜-臭氧工艺的1.7~3倍。锰铈催化膜-臭氧工艺在二级出水体系中最佳臭氧投加量为5 mg·L^(-1),此时工艺对微量污染物的去除率均大于80%,满足国家生态环境部《水回用指南再生水中药品和个人护理品类微量污染物处理技术》(T/CSES 42-2021)关于微量污染物去除的标准。锰铈催化膜-臭氧工艺对二级出水中TOC的去除率为32%,对UV_(254)的去除率为66%,去除的有机物主要是腐殖酸类荧光物质,出水无急性毒性。

To comprehensively reveal the removal characteristics of micro-pollutants and conventional pollutants in the secondary effluent by the MnCe-catalytic ceramic membrane-ozonation(O_3/MnCe-CM)process,the removal performance of O_3/MnCe-CM process for four typical micro-pollutants and conventional pollutants was studied at the ozone dosages from 2.5 to 5 mg·L^(-1)with O_3/CM as the control group.Moreover,the removal performance of membrane filtration for MnCe-CM was investigated with CM as the control group.The results show that the removal rates of atrazine,benzotriazole,DEET,and simazine by the O_3/MnCe-CM process were significantly improved in comparison to O_3/CM process.The kinetic constants of the O_3/MnCeCM process were 1.7-3 times those of the O_3/CM process at the ozone dosage of 5 mg·L^(-1).The optimal ozone dosage of the O_3/MnCe-CM process in the secondary effluent system was 5 mg·L^(-1),the average removal performance of four micropollutants was higher than 80%under this condition,which could meet the standard of《Guidelines for water reuse—Treatment technologies for pharmaceuticals and personal care products in reclaimed water》(T/CSES 42-2021)of the Ministry of Ecology and Environment.In addition,the removal rates of the O_3/MnCe-CM process for TOC and UV_(254)in the secondary effluent were 32%and 66%,respectively.The removed organic was mainly fluorescent humic acid substances,and no acute toxicity was detected in the effluent of the O_3/MnCe-CM process.