生物铁修复Cr(Ⅵ)污染土壤的性能及机理  

Performance and mechanism of Cr(Ⅵ) contaminated soil remediation by bio-iron

作　　者：程爱华[1] 郑蕾 CHENG Aihua;ZHENG Lei(College of Geology and Environment,Xi′an University of Science and Technology,Xi′an 710054,China)

机构地区：[1]西安科技大学地质与环境学院,西安710054

出　　处：《环境工程学报》2018年第10期2892-2898,共7页Chinese Journal of Environmental Engineering

基　　金：陕西省工业攻关计划项目(2013GY2-06)

摘　　要：以活性污泥与生物铁作为修复剂,对比时间、pH、污泥投加量、Cr(VI)初始浓度对活性污泥、生物铁去除土壤中Cr(VI)的影响;考察生物铁对土壤中Cr(VI)的还原率;采用SEM、XRD、XPS对生物铁修复前后的Cr(VI)污染土壤进行表征分析。实验结果表明:在土壤中,生物铁对Cr(VI)的修复效果优于活性污泥,当pH为6.0,Cr(VI)初始浓度为300 mg·kg^(-1),生物铁和活性污泥的投加量均为19.57 mg·g^(-1),修复时间为45 d时,土壤中Cr(VI)经活性污泥与生物铁修复后浓度分别为31.42、19.69 mg·kg^(-1),去除率分别为89.52%、94.12%。生物铁修复土壤Cr(VI)以还原作用为主,吸附为辅。Cr(VI)污染土壤被生物铁修复后出现了FeOOH、Fe_3O_4以及Fe_3O_4与FeCr2O4的混合物,部分Cr(VI)被还原为Cr(III),铁被氧化为Fe^(2+)、Fe^(3+)。In this study, activated sludge and bio-iron were cultivated in the same conditions as remediation reagents, and the effects of the influence factors such as time, pH, sludge dosage, and Cr（VI） initial concentration on Cr（VI） removalin soil were studied, as well as the reduction ratio of Cr（VI） in soil by bio-iron. The original and remediated Cr（VI） contaminated soils were characterized by SEM, XRD and XPS. Experimental results showed that bio-iron had a better effect on Cr（VI） removal in soil than activated sludge. When pH was 6.0, initial Cr（VI） concentration was 300mg·kg^-1, each dosage of bio-iron and activated sludge was 19.57mg·g^-1, and remediation time was 45d, the Cr（VI） concentrations in the remediated soils by activated sludge and bio-iron decreased to 31.42mg·kg^-1 and 19.69mg·kg^-1, and the corresponding removal ratios were 89.52% and 94.12%, respectively. The remediation of Cr（VI） in soil by bio-iron could be mainly attributed to the reduction effect, and absorption is an auxiliary function. The FeOOH, Fe3O4, mixture of Fe3O4 and FeCr2O4were observed in the Cr（VI） contaminated soil remediated by bio-iron. A partial Cr （VI） anions were reduced to Cr （III）, and iron was oxidized to Fe2＋ and Fe3＋.

关 键 词：生物铁 活性污泥 土壤 CR(VI) 还原 

分 类 号：X53[环境科学与工程—环境工程]