HA对铁屑还原去除水中六价铬的影响  

Reductive removal of Cr(VI) by iron filings in the presence of humic acid

作　　者：CISSOKO Naman 周密[1] 张珍[1,2] 包乐乐[1] 周娅[1] 翁嫣爽[1] 徐新华[1] 

机构地区：[1]浙江大学环境工程系,浙江杭州310027 [2]台州学院生命科学学院,浙江临海317000

出　　处：《浙江大学学报（理学版）》2009年第4期463-469,共7页Journal of Zhejiang University（Science Edition）

基　　金：国家自然科学基金资助项目(No.20407015);教育部新世纪优秀人才支持计划(NCET-06-0525)资助

摘　　要：采用废铁屑(Fe0)为主要工具修复受污染水体中的六价铬,考察了腐殖酸(HA)对Fe0还原六价铬的影响,并初步探讨了HA存在时,Fe0还原降解水中Cr(VI)的动力学.实验结果表明,HA对铁屑还原去除Cr(VI)存在一定的影响,提高HA浓度会导致Cr(VI)去除效率下降,但是在一定浓度范围内较为接近,当HA浓度提高到80mg·L-1时,抑制作用较为明显.HA存在时,Fe0还原去除Cr(VI)符合拟一级反应动力学,加入80mg·L-1的HA,铁屑去除Cr(VI)的反应速率常数相应由不加HA时的0.00481min-1降低为0.00199min-1;随着溶液初始pH值由3.0,4.0,6.0增加到10.0,反应速率常数相应由0.02657,0.0091,0.00222min-1下降到0.0003min-1.The reduction of Chromium（VI） by iron filings in the presence of humic acid （HA） was carried out during our investigation. At the same time, the degradation kinetics of Chromium（VI） by iron filings was discussed in the presence of HA. Our experimental results indicated that HA has a definite control on the reduction of Cr（VI） by iron filings. At low range concentrations, HA has both inhibitory and promotion effects on the reaction. Effects were comparatively close to each other. Following the progressive increase of HA concentration to 80 mg.L^-1 , the inhibitory role became more obvious. The degradation kinetics of Chromium（VI） by iron filings follows a pseudofirst-order reaction in the presence of HA. The rate constant k values of Chromium（VI） reduction decreased from 0.004 81 min^-1 in the absence of HA to 0.001 99 min 1 in the presence of 80 mg. L%-1 HA. For pHs 3.0, 4.0, 6.0 and 10.0, the kobs wereO. 026 6 min^-1, 0.009 1 min^-1, 0.002 2 min^-1 and0.000 3 min^-1, respectively.

关 键 词：腐殖酸 CR(VI) 铁屑 动力学 

分 类 号：X703[环境科学与工程—环境工程] X131.2