摘要
采用前置硫化法合成制备硫化纳米铁,研究其与过硫酸盐对硝基苯的联合降解效果,检测反应前后溶液中铁离子和TOC浓度变化,对反应前后的S-NZVI进行表征,分析S-NZVI和PS对NB的联合降解机制.以纳米硅胶溶液为胶结剂,以PS为活性成分,制备缓释PS溶胶,注入砂柱中扩散形成凝胶,与S-NZVI构成S-NZVI/PS组合反应带,研究其对模拟硝基苯污染地下水的原位修复效果.结果表明,S-NZVI能够高效去除NB并生成大量苯胺(AN),S-NZVI被PS氧化产生的Fe^2+与PS组成活化过硫酸盐,对AN具有较好的降解和矿化效果.当NB浓度为100mg/L、S-NZVI和PS的投加量分别为0.5,2.5g/L时,NB去除率达91%,AN出水浓度为1.96mg/L,TOC去除率达64.09%.反应后S-NZVI的主要铁氧化产物为Fe3O4和FeO(OH).反应带实验结果表明,S-NZVI/PS组合反应带可有效去除地下水的NB并高效消减NB还原产生的AN,当进水中NB浓度为100mg/L,流量为0.4mL/min,注入S-NZVI含量为1200mg/L的浆液200mL,二氧化硅含量为30%、PS含量为12.5%的PS凝胶4.8g时,S-NZVI/PS组合反应带7d内对AN的去除率最高达97.6%,NB当量累计去除率为83.7%.
Sulfidated-nanoscale zerovalent iron(S-NZVI)was prepared by pre-sulfide synthesis to study the degradation efficiency of nitrobenzene by S-NZVI and persulfate(PS).The degradation mechanism of reaction was investigated by detecting the change of iron ion concentration,TOC concentration and characterizing S-NZVI before and after the reaction.The S-NZVI/PS reaction zoon was established by injecting S-NZVI and gel which nano-silica solution was chosen as the binder and PS as the active components,to study the effect of in-situ remediation on simulated nitrobenzene contaminated groundwater.S-NZVI could effectively remove NB and generate a large amount of aniline(AN).The Fe^2+formed by PS oxidized S-NZVI and PS composition activate persulfate,which had a good degradation and mineralization effect on AN.When the concentration of NB was 100mg/L,the dosage of S-NZVI and PS was 0.5g/L and 2.5g/L respectively,the removal rate of NB was 91%,the effluent concentration of AN was 1.96mg/L,and the removal rate of TOC was 64.09%.The main iron oxidation products of S-NZVI after the reaction were Fe3O4 and FeO(OH).The results of reaction zone showed that the S-NZVI/PS reaction zone could effectively remove NB from groundwater and effectively remove AN produced by NB reduction.When the NB influent concentration was 100mg/L,the flow rate was 0.4mL,1200mg/L 200mL of S-NZVI and 4.8g PS gel with 30%silica and12.5%PS was injected,the removal rate of AN was up to 97.6%and the cumulative removal rate of NB equivalent was 83.7%,within 7d.
作者
朱颖一
叶倩
王明新
张金永
韩莹
ZHU Ying-yi;YE Qian;WANG Ming-xin;ZHANG Jin-yong;HAN Ying(School of Environmental&Safety Engineering,Changzhou University,Changzhou 213164,China;Jiangsu Yangtze River Delta Environmental Science&Technology Research Institute Co.Ltd.,Changzhou 213159,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2020年第10期4411-4420,共10页
China Environmental Science
基金
国家自然科学基金资助项目(41772240,21906009)
江苏省研究生科研与实践创新计划项目(SJCX19-0786,SJCX19-0801)。
关键词
硫化纳米铁
PS
NB
地下水
原位修复
sulfidated-nanoscale zerovalent iron
persulfate
nitrobenzene
groundwater
in-site remediation
