金属矿区土壤治理研究进展

针对金属矿山开采造成的土地破坏与污染,简述我国金属矿山土地生态治理现状,介绍国内外在金属矿山土地复垦、重金属污染的改良剂修复、植物修复等土壤修复技术进行的实践,探讨今后我国金属矿山土壤生态恢复的发展方向.

农田污染土壤生态治理研究现状

我国土壤污染形势严峻,土壤酸化、盐渍化严重,重金属含量高及农药施用不当等严重威胁了农业生产的可持续发展和人类健康安全。鉴于我国土壤污染仍比较严重,应从减少土壤污染物投入、土壤修复技术研究等多方面着手改变土壤污染现状,并通过外源和自身因素来分析农田土壤污染成因,借鉴国内外修复技术,有效治理受污染的农田土壤。

赣州不同级公路沿线农田土壤重金属污染评价研究

研究区域为赣州市章贡区至赣县王母渡镇之间的三级道路体系—即323国道(简称G323)、234省道(简称S234)以及348县道(简称X348)所构成的线形区域,主要研究这三级道路两侧的土壤中重金属(Pb、Cd、Cu、Zn)的含量及污染评价.利用单因子污染指数法和内梅罗综合污染指数法相结合的方法对其重金属污染综合指数进行评价,结果表明:县道≤100m的范围、省道≤200m的范围以及国道≤100m的范围之内均受到重金属污染.三级道路两侧土壤重金属污染综合指数均值的大小顺序为:国道(3.401)>省道(2.795)>县道(2.682);县道处西北侧(2.763)>东南侧(2.600);省道处西侧(2.941)>东侧(2.648);国道处西北侧(4.038)>东南侧(2.764).

赣州钨矿区及工业区蔬菜重金属含量及污染评价

通过A区为王母渡钨矿主矿区龙潭村,B区为赣州香港工业园,C区为赣州有色工业园,D区为赣州王母渡钨矿东埠头坑口上邦村,E区为赣县大田老稀土矿矿区的蔬菜作为研究对象,对蔬菜进行污染程度评价.结果表明,在A区龙潭村内,叶菜类中的紫叶菜中铅(Pb)含量超标,超标29.3%;紫叶菜的综合污染指数高于0.7,超过警戒限,属于尚清洁等级.B区赣州香港工业园区内,豇豆受到的污染程度最严重,超标292%,空心菜中的铅(Pb)含量超标为75%,茄子中的铅(Pb)超标161%;C区赣州有色工业园区内,豇豆中的铅(Pb)超标,超标288%;D区和E区赣州王母渡钨矿东埠头坑口上邦村内,蔬菜样品中的重金属含量均符合国家限量标准.

钨矿矿区土壤多种重金属含量及赋存形态研究

以赣州市赣县王母渡镇东埠头钨矿矿区开采区、尾砂库、矿区附近河流沿岸及矿区土壤为研究对象,选择该矿区污染土壤样本21个,采用王水消煮法对土壤样品进行处理,运用等离子体发射光谱仪(ICP-AES)测定土壤样品中Pb、As、Hg、Cr、Cd、Zn、Cu、Ni的含量.选用修正的BCR法测定矿区土壤中重金属元素的赋存形态,结果表明:As、Zn、Cr、Pb、Ni在外界条件影响下可转换为可交换态,矿区中残留选矿剂对重金属赋存形态的影响较大,As、Cd污染较为严重.

Study on the Acute Toxicity of Rare Earth Yttrium to Earthworms under the Stress of Leaching Agent Ammonium Sulfate

This study aimed to investigate the toxicity of rare earth ion yttrium under the stress of leaching agent ammonium sulfate （NH4）2SO4. [Method] By using earthworms as indicator organisms of environmental pol ution, acute toxic ef-fects of rare earth yttrium on earthworms under the stress of ammonium sulfate were investigated with filter paper contact method. [Result] Under single stress of rare earth yttrium, the semi-lethal concentration after 48 and 24 h was LC50=213.41 mg/L and LC50=322.63 mg/L, respectively. ② Under single stress of ammonium sul-fate, the semi-lethal concentration after 48 h and 24 h was LC50=13.89 g/L and LC50=15.05 g/L, respectively. ③ In combined treatment of low concentration （10 g/L） of ammonium sulfate and different doses of rare earth yttrium, the semi-lethal con-centration after 48 and 24 h was LC50=198.65 g/L and LC50=399.85 g/L, respective-ly; in combined treatment of middle concentration （14 g/L） of ammonium sulfate and different doses of rare earth yttrium, the semi-lethal concentration after 48 and 24 h was LC50=167.3 mg/L and LC50=256.73 mg/L, respectively; in combined treatment of high concentration （20 g/L） of ammonium sulfate and different doses of rare earth yttrium, the semi-lethal concentration after 48 h and 24 h was LC50=31.03 mg/L and LC50=127.65 mg/L, respectively. [Conclusion] Low concentration of ammonium sulfate could reduce the toxicity of rare earth yttrium to earthworms and produce certain antagonism against rare earth yttrium; middle concentration ammonium sulfate in-creased the toxicity of rare earth yttrium to earthworms and produced relatively sig-nificant synergistic effects; high concentration ammonium sulfate significantly in-creased the toxicity of rare earth yttrium to earthworms. Compared with ammonium sulfate, dead earthworms exposed to rare earth yttrium were more easily fractured, and living earthworms showed insensitive response to acupuncture.

Remediation of in-situ Leach Mining Contaminated Soil by Amendment-plant Synergism

This study aimed to remediate in-situ leach mining contaminated soil by amendment-plant synergism. The results showed that plant species exhibited ex-tremely significant effects on the concentration of nitrate nitrogen; to be specific, the concentration of nitrate nitrogen in soil planted with wheat was reduced from 692.19 mg/kg to lower than 100 mg/kg; when the mass ratio of amendment to soil reached 3：50 and the amendment particle size was 1-2 mm, the concentration of nitrate ni-trogen in soil planted with wheat was reduced to 43 mg/kg. The amendment type exhibited extremely significant effects on the concentration of ammonium nitrogen; to be specific, when the mass ratio of amendment to soil reached 10：50, the concen-tration of ammonium nitrogen in soil added with 2-3 mm zeolite was reduced from 23 593.75 to 3 300 mg/kg on day 15. Amendments and plants mainly exhibited desorption performance for sulfate radical in soil, and the amendment type extreme-ly significantly affected the concentration of sulfate radical; to be specific, the con-centration of sulfate radical in soil added with limestone increased from 370 mg/kg to 900 mg/kg on day 7.

连续管式原位注入化学氧化技术对某有机污染场地地下水的修复效果

针对传统地下水原位注入化学氧化技术存在注入深度浅、效率低等问题,采用连续管和高压水射流技术实现地下水原位修复药剂钻注一体化和水射流钻进,以提高效率和深层修复。以某退役化工厂地下水中的氯苯为目标污染物,基于自主开发的连续管式原位注入化学氧化技术开展了中试规模的实验研究,基于现场实验确定原位注入药剂影响半径并评估了修复效果。结果表明,药剂影响半径可达2 m,且药剂扩散趋势与场地总体地下水流场的流向基本吻合;经原位化学氧化处理后,实验区地下水中氯苯检测质量浓度低于400μg·L^(−1),即采用连续管式原位注入化学氧化技术实现了实验区地下水中氯苯的有效去除。本研究可为连续管注入技术在地下水原位修复中的应用提供参考。