【作者】 徐超；

【导师】 廖柏寒；

【作者基本信息】 中南林业科技大学 ， 环境科学， 2012， 硕士

【摘要】 通过对衡阳某地、郴州某地和株洲某地土壤的采样和调查,了解当地耕作土壤的重金属污染状况。在实验室向衡阳某地和郴州某地的重金属污染土壤添加单一固化剂和组配固化剂,添加浓度均为6g·kg-1。通过毒性浸出实验(TCLP),研究单一固化剂和组配固化剂对土壤Pb、Cd、Cu、Zn浸出量的影响,评价两类固化剂的固化效果,筛选出固化效果最好的固化剂,并进行浓度梯度试验。同时在株洲某地新马村建立径流场,向径流场内的土壤添加固化剂,添加浓度为6g·kg-1,以人工泼水的方式模拟降雨,收集地表径流水和渗漏水,分析地表径流水和渗漏水中重金属含量。试验主要结果如下：(1)在衡阳某地采集的耕作土壤样品中,Pb、Cd、Zn含量均超过了土壤环境质量三级标准；在郴州某地采集的土壤样品中,Pb、Cd含量超过了土壤环境质量三级标准,土壤Zn含量超过一级标准；在株洲某地采集的耕作土壤样品中Cd含量超过了土壤环境质量三级标准,Pb和Zn含量均超过了土壤环境质量一级标准。(2)在单一固化剂中,石灰石对土壤重金属的综合固化效果最好,相比对照,Pb、Cd、Cu、Zn的土壤浸出量分别下降了29.5%、100%、68.6%、49.6%；在组配固化剂中,组配比例为1：2的固化剂Ⅱ(硅藻土、石灰石)的综合固化效果最好,相比对照,Pb、Cd, Cu、Zn在衡阳某地供试土壤中的浸出量分别下降了54.3%、100%、27.3%、63.8%,在郴州某地供试土壤中的浸出量分别下降了100%、48.4%、64.8%、71.2%。(3)对组配比例为1：2的固化剂Ⅱ(硅藻土、石灰石)进行浓度梯度筛选,结果发现,添加浓度为6g·kg-1的固化效果最好,相比对照,其土壤Pb、Cd、 Cu、Zn的浸出量分别下降了54.3%、100%、27.3%、63.8%。(4)无论是从经过单一固化剂处理过的径流区域收集的地表径流水和渗漏水,还是从未经任何处理的对照径流区域收集的地表水和渗漏水,都无法检测到重金属的含量。更多还原

【Abstract】 In order to understand heavy metal pollution of planting soils, sampling and surveys of soil samples were conducted in someplace in Hengyang, someplace in Chenzhou, someplace in Zhuzhou. Single curing agents and group matching curing agents with a concertration of6g·kg-1were added to the soils of heavy metal contaminated in Hengyang and Chenzhou in the laboratory. Research on effects of single curing agents and group matching curing agents addition on the leaching contents of soil Pb, Cd, Cu and Zn, evaluation the effects of two types of curing agents on stabilization of soil heavy metals, selection of curing agents which had the best curing effect, conduction of concentration gradient test were conducted through extraction procedure for leaching toxicity (TCLP). A runoff field was established in Zhuzhou, in which curing agents were added to the soils with a concentration of6g·kg-1, rainfall was simulated in the way of artificial splashing, surface runoff water and seepage water were collected and analyzed for the contents of heavy metals. The primary results of the experiments were as follows:(1) In the farming soil samples collected from Hengyang, Pb, Cd and Zn contents were higher than the third level of soil environmental quality standard (SEQS). In the soils from Shihupu village in Chenzhou, Pb and Cd content were higher than the third level of SEQS,.Zn contents higher than the first level of SEQS. Cd content was higher than the third level of SEQS in the soils from Zhuzhou, and Pb and Zn contents exceeded the first level of SEQS.(2) Compared to the control, limestone was the best curing agent to stabilize soil heavy metals among six single curing agents, and decreased the leaching contents of Pb, Cd, Cu and Zn from the soils by29.5%,100%,68.6%, and49.6%, respectively. For group matching curing agents, the best curing effects for soil heavy metals showed for curing agent II with a ratio of1:2for diatomite and limestone. Compared to the control, this curing agent reduced the leaching contents of Pb, Cd, Cu and Zn by54.3%,100%,27.3%, and63.8%from the soils in Hengyang, and by100%,48.4%, 64.8%, and71.2%from the soils in Chenzhou, respectively.(3) As a result of concentration gradient test for curing agent II with a ratio of1:2for diatomite and limestone, the best curing effects for stabilization of soil heavy metals were showed for the addition of this curing agent with the concentration of6g-kg-1compared to the control, and the leaching contents of Pb, Cd, Cu and Zn from the soils were decreased by54.3%,100%,27.3%and63.8%, respecti vely.(4) Heavy metals were not detected either for the surface runoff waters or for the seepage waters from the runoff field in Zhuzhou no matter the soils treated with single curing agents or not.更多还原