摘要
选用多硫化钙为还原剂,进行地下水中Cr（Ⅵ）去除效果的研究。主要考察了多硫化钙投加量、溶液p H、温度、Mn（II）、Fe（III）、腐殖酸（HA）存在条件下,对多硫化钙处理Cr（Ⅵ）效果的影响。结果表明：当多硫化钙与Cr（Ⅵ）的摩尔比由1∶1变到5∶1时,去除率从41.03%增加到100.00%;溶液p H值从6.0增上升到9.0时,去除率下降27.16%;水环境温度由（7±1）℃增加到（27±1）℃时,去除率达到100.00%所需反应时间,缩短了4~6倍;当地下水中含有Mn（II）,随着Mn（II）质量浓度升高（0.00~10.00 mg·L-1）,Cr（Ⅵ）浓度低于检测线所需要的时间缩短3倍;当地下水中含有Fe（III）,Fe（III）质量浓度从0.00 mg·L-1增加到10.00 mg·L-1,去除率增加9.05%;当地下水中含有HA（0.00~15.00 mg·L-1）,去除率由99.31%降低至90.28%。（7）多硫化钙与六价铬的反应产物的X射线衍射光谱图像中2θ值为18.2°、19.36°、26.67°与Cr（OH）3,2θ值为23.02°与单质S的标准卡片匹配度较高。另外,对含有11.36 mg·L-1 Cr（Ⅵ）实际污染地下水的处理效果表明,Cr（Ⅵ）的去除率达到99.78%,残留浓度达到GB/T 1448—1993地下水质量标准III类标准,说明多硫化钙修复实际铬污染地下水具有良好的应用前景。
Effectiveness of chromium reduction by calcium polysulfide was the obiective of this paper. Factrors were investigated such as pH, CaS5 concentrations, temperature and Mn（II）, Fe（III）, HA-contained water. When the rato of CaS5 and Cr（VI） ranged from 1∶1 to 5∶1, the Cr（VI） reduction rate inceased from 41.03%to 100.00%;The pH value of the water environmemt differed from 6.0 to 9.0, the reduction rate of Cr（VI） was 27.16%;The balance time was shorten 4~6 times when temperature of the water environmemt rised from （7±1） ℃ to （27±1） ℃; As Mn（II） was the principal component of Cr（VI）-contained water, the higher Mn（II） concentration（0.00~10.00 mg·L-1）, the faster reaction velocity between CaS5 and Cr（VI）; The concentration of Fe（III） consisting in groundwater transfered from 0.00 mg·L-1 to 10.00 mg·L-1, the removal rate increased by 9.05%;When HA existed in the ground water（0.00~15.00 mg·L-1）, the Cr（VI） reduction rate varied from 99.31%to 90.28%;The XRD showed the products of the reaction between calcium polysulfide and hexalvant chromium were Cr（OH）3 and S, whose 2θdegree corresponded to 18.2°, 19.36°, 26.67° and 23.02°. When calcium polysulfide treated 11.38 mg·L-1Cr（VI）-contami-nated ground water ,removal rate of Cr（VI） can reach 90.28%. Output concentration of Cr（VI） can reach to III class of Quality standard for groundwater GB/T 1448-93. Calcium polysulfide has been found a promising reductant in the treatment of Cr（VI）-contained groundwater.
出处
《生态环境学报》
CSCD
北大核心
2015年第2期294-299,共6页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(41372236)
