CMC-nZVI对高硫矿山土壤中铜的固定效果及机理

发布时间：2018-05-24 00:46

本文选题：零价铁 + 高硫土壤　；参考：《环境科学学报》2017年11期

【摘要】：纳米零价铁(Nanoscale zero-valent iron,n ZVI)因具有较大比表面积和较强还原能力,常被用于原位修复变价重金属污染土壤,而对其应用于高硫富铜矿山土壤的修复及机理研究却鲜见报道.本研究以羧甲基纤维素-纳米零价铁(CMC-n ZVI)为供试材料,以广东省大宝山矿区高硫富铜土壤为供试土壤,按水土比1 g∶5 m L将CMC-n ZVI与矿山土壤混合均匀,通过毒性淋溶提取、重金属形态和酸可挥发性硫化物提取等实验,探究了CMC-n ZVI对矿山土壤中Cu的固定效果及机制.结果表明:(1)CMC-n ZVI对高硫土壤中的Cu具有极好的固定效果,毒性淋溶提取实验结果表明,n ZVI处理土壤中Cu的浸出浓度低于15 mg·kg-1,达到安全标准;(2)n ZVI可促进厌氧微生物的活性,促进土壤中大量硫酸盐被还原,因此Cu可能被Fe S、Fe S2吸附或直接生成硫化物沉淀,最终固定于土壤中;(3)新生成的无定形或微晶型次级铁矿物易通过吸附或共沉淀将游离的Cu(II)固定.
[Abstract]:Nanoscale zero-valent ironn ZVI (Nanoscale zero-valent ironn ZVI) is often used in situ remediation of contaminated soils contaminated by variable valence heavy metals due to its large specific surface area and strong reduction ability, but few reports have been reported on its application in remediation and mechanism of soils in high sulfur and copper rich mountains. In this study, CMC-n ZVI was used as test material, and high sulfur and copper rich soil in Dabaoshan mining area, Guangdong Province, was used as test material. CMC-n ZVI was mixed with mine soil according to water and soil ratio of 1 g: 5 mL, and was extracted by toxic leaching. The effects and mechanism of CMC-n ZVI on Cu fixation in mine soil were studied in the experiments of heavy metal speciation and extraction of volatile sulfides. The results showed that CMC-n ZVI had excellent fixation effect on Cu in high-sulfur soils. The results of toxic leaching and extraction experiments showed that the leaching concentration of Cu in the soil treated with ZVI was less than 15 mg 路kg ~ (-1), which reached the safety standard and could promote the activity of anaerobic microorganisms. It promotes the reduction of a large amount of sulphate in soil, so Cu may be adsorbed by Fe Si Fe S 2 or precipitated directly by sulphide. The newly formed amorphous or microcrystalline secondary iron ores are easily immobilized by adsorption or coprecipitation.
【作者单位】：中山大学环境科学与工程学院;广西环境污染控制理论与技术重点实验室桂林理工大学环境科学与工程学院;广东省环境污染控制与修复技术重点实验室;
【基金】：环保公益性行业科研专项(No.201509037) 广东省自然科学基金(No.2014A030313200) 广州市科技支撑项目(No.201607010065) 高校基本业务费项目(No.15lgjc36)~~
【分类号】：X53

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