生物炭负载硫化改性纳米零价铁去除水中的Cr(Ⅵ)  

Experimental study on the removal of Cr(Ⅵ)from water by biochar-based sulfide modification loaded with nano-zero valent iron

作　　者：潘虹 王兴润[2] 王雷 张羽嘉 颜湘华[2] PAN Hong;WANG Xingrun;WANG Lei;ZHANG Yujia;YAN Xianghua(School of Environmental Science and Engineering,Nanjing Tech University;Chinese Research Academy of Environmental Sciences)

机构地区：[1]南京工业大学环境科学与工程学院 [2]中国环境科学研究院

出　　处：《环境工程技术学报》2023年第2期663-668,共6页Journal of Environmental Engineering Technology

基　　金：国家重点研发计划项目(2018YFC1802200)。

摘　　要：为研发治理地下水Cr(Ⅵ)污染的可行除铬材料,以碳热法制得生物炭负载纳米零价铁(BC-nZVI),并通过对BC-nZVI硫化改性制备得到改性材料(M-BC-nZVI),采用除铬容量、铬铁比(Cr/Fe)、反应活性分析M-BC-nZVI的除铬优势,通过模拟柱试验建立失效速率模型,从而推算M-BC-nZVI完全失效的除铬容量,最后与相关文献数据进行对比,分析M-BC-nZVI除Cr(Ⅵ)的应用可行性。结果表明:M-BC-nZVI材料的除铬容量、Cr/Fe、拟一级反应速率常数(k_(obs))分别是BC-nZVI的1.86倍、1.95倍和3.00倍,因此相对于BC-nZVI来说M-BC-nZVI更具除铬优势;各模拟柱在运行过程中无明显堵塞情况,且随着进水浓度的升高,M-BC-nZVI的失效速率常数变大。当失效除铬速率为初始除铬速率的1.0%、进水Cr(Ⅵ)浓度为5 mg/L时,除铬容量最高,可以达到12.70 mg/g;对比M-BC-nZVI与其他文献报道的铁基材料及铁基改性材料的Cr/Fe可知,M-BC-nZVI的Cr/Fe为其他文献的1.06~42.06倍,故从材料的除铬性能来看,M-BC-nZVI应用于可渗透反应墙处理地下水Cr(Ⅵ)污染可行。In order to treat Cr(Ⅵ)pollution in groundwater,biochar-supported nano-zero valent iron(BC-nZVI)was prepared by the carbothermal method,and the modified material(M-BC-nZVI)was prepared by vulcanization modification of BC-nZVI.The chromium removal capacity,Cr to Fe ratio(Cr/Fe)and the reactivity of M-BC-nZVI were used to analyze the superiority of M-BC-nZVI for chromium removal.A failure rate model was established through the simulated column test to calculate the chromium removal capacity of M-BC-nZVI that completely failed.Finally,the application feasibility of M-BC-nZVI in removing Cr(Ⅵ)was analyzed by comparing it with the relevant studies.The results showed that the removal capacity,Cr/Fe and pseudo-first-order reaction rate constant(k_(obs))of M-BC-nZVI were 1.86,1.95 and 3.00 times higher than those of BC-nZVI,respectively.Therefore,compared with BC-nZVI,M-BC-nZVI had certain advantages in various aspects.Each simulated column had no obvious blockage during operation,and the failure rate constant of M-BC-nZVI increased with the increase of influent concentration.The highest chromium removal capacity(12.70 mg/g)reached when the failure chromium removal rate was 1.0%of the initial chromium removal rate and the influent Cr(Ⅵ)concentration was 5 mg/L.By comparing Cr/Fe of M-BC-nZVI with iron-based materials and iron-based modified materials reported in other studies,Cr/Fe of M-BC-nZVI was 1.06 to 42.06 times that of other studies.Therefore,based on the chromic removal performance of the material,it was feasible to apply M-BC-nZVI to permeable reactive barrier to treat Cr(Ⅵ)pollution in groundwater.

关 键 词：生物炭 纳米零价铁 硫化改性 六价铬 模拟柱 

分 类 号：X523[环境科学与工程—环境工程]