赤泥活化过一硫酸盐降解环丙沙星:性能和机制  

Red Mud-activated Peroxymonosulfate for Ciprofloxacin Degradation:Efficiency and Mechanism

作　　者：史京转[1] 魏红[1] 周孝德[1] 李克斌[2] 史颖娟 SHI Jing-zhuan;WEI Hong;ZHOU Xiao-de;LI Ke-bin;SHI Ying-juan(State Key Laboratory Base of Eco-Hydraulic Engineering in Arid Area,Xi'an University of Technology,Xi'an 710048,China;Key Laboratory of Synthetic and Natural Functional Molecule Chemistry,Ministry of Education,Northwest University,Xi'an 710069,China;Shaanxi Reconnaissance Design&Research Institute of Water Environmental Engineering,Xi'an 710021,China)

机构地区：[1]西安理工大学省部共建西北旱区生态水利国家重点实验室,西安710048 [2]西北大学合成与天然功能分子教育部重点实验室,西安710069 [3]陕西水环境工程勘测设计研究院,西安710021

出　　处：《环境科学》2020年第4期1743-1751,共9页Environmental Science

基　　金：国家自然科学基金项目(51979223);陕西省自然科学基金项目(2017JM5082);陕西省水利科技项目(2013slkj-07);陕西省教育厅项目(16JK1567)。

摘　　要：为提高赤泥的综合利用及抗生素有机废水的深度处理,以赤泥(red mud,RM)为催化剂、环丙沙星(ciprofloxacin,CIP)为目标污染物,系统研究了RM活化过一硫酸盐(peroxymonosulfate,PMS)降解CIP的效果和机制.结果表明,含有Fe、Al和Ca等金属氧化物,具有较大比表面积(10.96 m^2·g^-1)和复杂孔道结构的RM能够有效增强PMS对CIP的降解速率和效果.自由基捕获剂甲醇、叔丁醇和苯酚的抑制实验结果进一步说明,体系产生的SO-4·和HO·在RM表面与CIP发生氧化反应.温度、PMS浓度和RM投加量影响CIP的降解.温度升高反应速度加快,反应活化能为5.74 kJ·mol^-1;PMS浓度增加,体系产生更多SO-4·和HO·,CIP的降解率升高;RM存在最佳投加量1.0 g·L^-1.HPLC/MS/MS共检测到8种降解产物,CIP分子中的哌嗪环易受活性物质进攻,CIP主要通过2种途径进行降解.本研究表明RM是一种极具潜力的廉价催化剂,可用于活化过一硫酸盐处理含抗生素的污染废水.In this paper,the effects and mechanism of ciprofloxacin(CIP)degradation with peroxymonosulfate(PMS)catalyzed by solid waste red mud(RM)was firstly studied.The results indicated that RM has large specific surface area(10.96 m^2·g^-1)and complex pore structure,containing ferric,alumina and calcium oxide,which enhanced ciprofloxacin degradation by PMS effectively.Radical quenching experiments revealed that SO-4·and HO·were contributed to ciprofloxacin oxidation,and the reaction was mainly occurred on RM’s surface.An increase in temperature could accelerate CIP degradation,and the corresponding reaction activation energy Ea was about 5.74 kJ·mol^-1.Meanwhile,CIP degradation rate increased with PMS concentration and the optimal dosage of RM was 1.0 g·L^-1.Eight degradation intermediates were identified using HPLC/MS/MS,and consequently,CIP was degraded mainly through two pathways;the piperazine groups were preferentially attacked by active free radicals.This study further indicated that RM is a cheap catalyst and can be potentially used in the treatment of antibiotic contaminated wastewater.

关 键 词：赤泥(RM) 过一硫酸盐(PMS) 环丙沙星(CIP) 羟基自由基 降解路径 

分 类 号：X131.2[环境科学与工程—环境科学]