江西永平铜矿排土场土壤质量评价及土壤修复技术研究
发布时间：2019-06-10 03:54
【摘要】：以江西省永平铜矿排土场土壤为研究对象，在分析土壤理化性质的基础上，对排土场土壤质量进行了评价。通过室内实验，研究了不同土壤重金属活化剂对重金属解吸效果的影响，对土壤重金属潜在的环境风险进行了评估，同时开展室外试验，综合分析得到土壤重金属稳定剂协助植物稳定修复技术的可行方案。主要研究结论如下： （1）西部土壤pH值低于东部，大部分采样点的土壤阳离子交换容量均低于10cmol/kg，土壤质地为壤土或者砂土；采用模糊综合评价法对排土场土壤养分状况和重金属污染程度进行评价：排土场主要污染因子为Cu、Cd、Zn，重金属的污染程度排序为CuCdZnPb，排土场土壤重金属污染等级均为重度污染；土壤全钾和全氮含量极低，土壤养分等级为极度贫乏。高重金属含量和低土壤养分是限制永平铜矿排土场土壤修复的主要因素。 （2）草酸（CA）、柠檬酸（OA）、EDTA、NTA4种提取剂对Cu、Zn、Cd的提取效果呈现不同规律。当提取剂浓度低于0.2M时，EDTA对Cu和Zn的提取效果最好；而当提取浓度高于0.2M时，草酸的提取效果最优。对于Cd，DE1和DE3镉提取量大小顺序为：EDTACA NTA OA，DE2、DE4和DW顺序为：EDTA CA≈NTAOA。用改进BCR连续提取法研究了Cu、Zn、Cd化学形态，Cu元素以残渣态和还原态为主，Zn以残渣态为主，Cd以易迁移的酸溶态为主。经过0.2M草酸、柠檬酸、EDTA、NTA提取后，主要是酸溶态和还原态的重金属被提取去除。环境风险评估结果表明，经过土壤活化剂提取后，土壤重金属直接环境风险显著降低，但是潜在环境风险依然存在。 （3）通过植物生长指标和重金属累积含量指标评价不同固化剂联合植物修复技术的修复效果。所选植被对重金属均有一定耐受性，植被空间布局合理；六种土壤改良剂方案均能有效促进植物修复，其中鸡粪有机肥改良效果优于蚯蚓粪有机肥，草木灰和有机肥联合使用效果最好。比较外业实验设计的几种土壤改良方案，最优的为：在污染土壤上铺设20cm客土并添加少量石灰速效中和剂，采用草木灰和鸡粪有机肥作为固化剂，，该方案有利于植被更好更快定植，进而实现植被对重金属的稳定修复。
[Abstract]:Taking the soil of Yongping Copper Mine dump in Jiangxi Province as the research object, the soil quality of the dump site was evaluated on the basis of analyzing the physical and chemical properties of the soil. Through laboratory experiments, the effects of different soil heavy metal activators on the desorption of heavy metals were studied, the potential environmental risks of heavy metals in soil were evaluated, and outdoor experiments were carried out at the same time. The feasible scheme of soil heavy metal stabilizer to assist plant stable remediation technology was obtained. The main conclusions are as follows: (1) the pH value of the western soil is lower than that of the east, the soil cation exchange capacity of most sampling sites is less than 10 cmol 路kg, and the soil texture is loam or sandy soil; The soil nutrient status and heavy metal pollution degree of dump were evaluated by fuzzy comprehensive evaluation method. The main pollution factor of Cu,Cd,Zn, was CuCdZnPb,. The heavy metal pollution grade of the soil in the dump was heavy pollution. The contents of total potassium and total nitrogen in soil were very low, and the grade of soil nutrients was extremely poor. High heavy metal content and low soil nutrients are the main factors restricting soil remediation in Yongping Copper Mine dump. (2) the extraction effect of oxalic acid (CA), citric acid (OA), EDTA,NTA4 on Cu,Zn,Cd was different. When the concentration of extractant was lower than 0.2m, EDTA had the best extraction effect on Cu and Zn, while when the concentration was higher than 0.2m, the extraction effect of oxalic acid was the best. For Cd,DE1 and DE3, the order of cadmium extraction is: EDTACA NTAOA, DE2,DE4 and DW: EDTACA 鈮
本文编号：2496150
[Abstract]:Taking the soil of Yongping Copper Mine dump in Jiangxi Province as the research object, the soil quality of the dump site was evaluated on the basis of analyzing the physical and chemical properties of the soil. Through laboratory experiments, the effects of different soil heavy metal activators on the desorption of heavy metals were studied, the potential environmental risks of heavy metals in soil were evaluated, and outdoor experiments were carried out at the same time. The feasible scheme of soil heavy metal stabilizer to assist plant stable remediation technology was obtained. The main conclusions are as follows: (1) the pH value of the western soil is lower than that of the east, the soil cation exchange capacity of most sampling sites is less than 10 cmol 路kg, and the soil texture is loam or sandy soil; The soil nutrient status and heavy metal pollution degree of dump were evaluated by fuzzy comprehensive evaluation method. The main pollution factor of Cu,Cd,Zn, was CuCdZnPb,. The heavy metal pollution grade of the soil in the dump was heavy pollution. The contents of total potassium and total nitrogen in soil were very low, and the grade of soil nutrients was extremely poor. High heavy metal content and low soil nutrients are the main factors restricting soil remediation in Yongping Copper Mine dump. (2) the extraction effect of oxalic acid (CA), citric acid (OA), EDTA,NTA4 on Cu,Zn,Cd was different. When the concentration of extractant was lower than 0.2m, EDTA had the best extraction effect on Cu and Zn, while when the concentration was higher than 0.2m, the extraction effect of oxalic acid was the best. For Cd,DE1 and DE3, the order of cadmium extraction is: EDTACA NTAOA, DE2,DE4 and DW: EDTACA 鈮
本文编号：2496150
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