摘要
针对氯代烃的去除,铁的双金属纳米材料被证实具有十分广阔的应用前景。然而,大量研究表明基于铁的双金属材料在还原条件下对低氯代烷烃活性不高。因此,该研究基于ACF-Fe/Ni构建还原-氧化耦合体系,系统地探究对四氯化碳(CT)降解及其脱氯产物矿化的效能及机制,并深入地探讨ACF-Fe/Ni剂量、CT初始浓度、H_(2)O_(2)的浓度及环境温度对CT去除效率的影响。结果表明,基于ACF-Fe/Ni的还原-氧化耦合体系能够高效地去除CT。在ACF-Fe/Ni投加量为0.50 g/L、溶液初始pH为7.0、6.0 mg/L的CT及20.0 mmol/L的H_(2)O_(2)反应条件下,CT及其脱氯产物之间的碳平衡值仅为17.2%,TOC去除率达到18%,相比较单独ACF-Fe/Ni还原体系下CT的矿化度(6%),有了较大的提升。ACF-Fe/Ni投加量的增加能够明显地提升CT的降解效率及其脱氯产物DCM的去除率;H_(2)O_(2)浓度最优值为20.0 mmol/L;羟基自由基(·OH)为氧化体系中主要存在的活性自由基,对DCM的降解矿化起到了主导作用。
Iron-based bimetallic nano-materials used for the removal of chlorinated hydrocarbons have proved to be a broad application prospect.However,reported studies revealed that low-chlorinated alkanes had low activity with iron-based bimetallic nanomaterials under reducing condition.In this paper,investigation was conducted to build a reduction-oxidation coupling reactor based on ACF-Fe/Ni,systematically exploring the efficiency and mechanism of CT degradation and its products mineralization.In addition,the influences of ACF-Fe/Ni dosage,CT initial concentration,H_(2)O_(2) concentration and ambient temperature on CT removal efficiency were intensively studied.The results showed that the reduction-oxidation coupling reactor based on ACF-Fe/Ni could efficiently remove CT.Under the reaction condition such as ACF-Fe/Ni dosage of 0.50 g/L,initial solution pH 7.0,CT concentration 6.0 mg/L and H_(2)O_(2) concentration 20.0 mmol/L,the carbon balance value between CT and its dechlorination products was only 17.2%,and TOC removal was 18%.Compared with the dechlorination of CT under the ACF-Fe/Ni reduction system alone(6%),TOC removal could be considerably improved.An increase of the dosage of ACF-Fe/Ni could significantly upgrade the degradation efficiency of CT and DCM removal;and the optimal value of H_(2)O_(2) concentration was 20.0 mmol/L.Furthermore,·OH was the main active free radical in the oxidation system,which played a vital role in the removal of DCM.
作者
金歆
陈海
杨琦
JIN Xin;CHEN Hai;YANG Qi(Department of Architecture and Civil Engineering,West Anhui University,Lu'an 237012,China;Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing 100083,China;MOE Key Lab of Groundwater Circulation and Environmental Evolution,China University of Geosciences-Beijing,Beijing 100083,China;Beijing Key Laboratory of Water Resources&Environmental Engineering,China University of Geosciences-Beijing,Beijing 100083,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2021年第8期108-115,共8页
Environmental Science & Technology
基金
皖西学院自然科学研究项目(WGKQ2021017)
教育部重点实验室开放课题基金(20191450497)。
关键词
氯代烃
铁基双金属材料
还原脱氯
高级氧化技术
·OH
chlorinated hydrocarbons
iron-based bimetallic nanomaterials
reductive dechlorination
advanced oxidation processes(AOPs)
·OH
