硫化零价铁去除水中钼酸盐的效能与机理  

Insights into the performance of sulfidated zero-valent iron toward molybdenum removal

作　　者：牛梦凡 张雪莹[2,3] 蔡祖明 吴浩然 乔俊莲 孙远奎[1] NIU Meng-fan;ZHANG Xue-ying;CAI Zu-ming;WU Hao-ran;QIAO Jun-lian;SUN Yuan-kui(College of Ecology and Environmental Science,East China Normal University,Shanghai 200241,China;College of Environmental Science and Engineering,Tongji University,Shanghai 200092,China;Arcplus Group PLC East China Architectural Design&Research Institute Co.,Ltd,Shanghai 200002,China;Beijing Electric Power Economic Technology Institute,Beijing 100055,China)

机构地区：[1]华东师范大学生态与环境科学学院,上海200241 [2]同济大学环境科学与工程学院,上海200092 [3]华东建筑设计研究院有限公司,上海200002 [4]北京电力经济技术研究院有限公司,北京100055

出　　处：《中国环境科学》2023年第4期1620-1627,共8页China Environmental Science

基　　金：国家自然科学基金资助项目(21876129)。

摘　　要：钼矿的开采及含钼产品的生产与使用导致水中钼污染问题日益突出.为明确硫化零价铁(S-ZVI^(bm))去除水中钼酸盐的效能及作用机理,采用球磨法制备S-ZVI^(bm),进而探究S-ZVI^(bm)在有氧条件下去除Mo(VI)的反应动力学,并采用同步辐射技术等表征手段分析其反应机理.结果表明:硫化可显著加速零价铁的吸氧腐蚀过程,进而可将Mo(VI)的去除速率及去除容量分别提高3.6~42.3倍及1.7~3.2倍.与未改性零价铁相比,S-ZVI^(bm)可对抗Mo(VI)的致钝作用,进而可在更高的Mo(VI)浓度及更宽的pH值范围内实现Mo(VI)的有效去除.同步辐射技术表征结果显示,尽管硫化预处理可提高零价铁去除Mo(VI)的效能,但并未改变零价铁去除Mo(VI)的作用机理,即S-ZVI^(bm)仍主要通过化学吸附来实现Mo(VI)的去除.Nowadays,molybdenum(Mo)pollution in natural waters has become an increasing threat to human beings and microorganisms.Although zero-valent iron(ZVI)is considered to be an environmentally friendly approach for effective Mo(VI)sequestration,the low reactivity of traditional ZVI particles largely limits the ZVI application in real practice.To address this issue,sulfidated ZVI(S-ZVI^(bm))was prepared by a ball-milling method and its performance toward Mo(VI)removal was systematically evaluated in this work.Results showed that the sulfidation treatment could greatly accelerate the ZVI corrosion in the presence of oxygen,and thereby markedly improve both the rate and capacity of Mo(VI)removal by ZVI.In specific,the observed rate constants(kobs)of Mo(VI)removal by S-ZVI^(bm) were determined to be 0.059~0.866h–1 at initial pH 6.0,which were 3.6~42.3 folds higher than that of unmodified ZVI.Likewise,the Mo(VI)removal capacity was increased from 9.86 to 31.9mg/g upon sulfidation.Collectively,it was found that the sulfidation treatment could eliminate the passivating impact of Mo(VI)on ZVI corrosion and thus enable the S-ZVI^(bm) particles to sequestrate Mo(VI)effectively.Mechanically,X-ray absorption fine structure spectroscopy revealed that Mo(VI)was mainly sequestrated via chemical adsorption rather than via reduction.Moreover,it was found that sulfidation amendment did not alter the Mo(VI)removal pathway by ZVI,despite it can improve the Mo(VI)removal efficiency greatly.These findings could provide some insights into the application of S-ZVI^(bm) in metal(loid)s-contaminated water treatment.

关 键 词：零价铁 硫化 化学吸附 钼酸盐 X射线吸收精细结构谱 

分 类 号：X131[环境科学与工程—环境科学]