【摘要】：以江西省永平銅礦排土場土壤為研究對象，在分析土壤理化性質(zhì)的基礎上，對排土場土壤質(zhì)量進行了評價。通過室內(nèi)實驗，研究了不同土壤重金屬活化劑對重金屬解吸效果的影響，對土壤重金屬潛在的環(huán)境風險進行了評估，同時開展室外試驗，綜合分析得到土壤重金屬穩(wěn)定劑協(xié)助植物穩(wěn)定修復技術的可行方案。主要研究結論如下： （1）西部土壤pH值低于東部，大部分采樣點的土壤陽離子交換容量均低于10cmol/kg，土壤質(zhì)地為壤土或者砂土；采用模糊綜合評價法對排土場土壤養(yǎng)分狀況和重金屬污染程度進行評價：排土場主要污染因子為Cu、Cd、Zn，重金屬的污染程度排序為CuCdZnPb，排土場土壤重金屬污染等級均為重度污染；土壤全鉀和全氮含量極低，土壤養(yǎng)分等級為極度貧乏。高重金屬含量和低土壤養(yǎng)分是限制永平銅礦排土場土壤修復的主要因素。 （2）草酸（CA）、檸檬酸（OA）、EDTA、NTA4種提取劑對Cu、Zn、Cd的提取效果呈現(xiàn)不同規(guī)律。當提取劑濃度低于0.2M時，EDTA對Cu和Zn的提取效果最好；而當提取濃度高于0.2M時，草酸的提取效果最優(yōu)。對于Cd，DE1和DE3鎘提取量大小順序為：EDTACA NTA OA，DE2、DE4和DW順序為：EDTA CA≈NTAOA。用改進BCR連續(xù)提取法研究了Cu、Zn、Cd化學形態(tài)，Cu元素以殘渣態(tài)和還原態(tài)為主，Zn以殘渣態(tài)為主，Cd以易遷移的酸溶態(tài)為主。經(jīng)過0.2M草酸、檸檬酸、EDTA、NTA提取后，主要是酸溶態(tài)和還原態(tài)的重金屬被提取去除。環(huán)境風險評估結果表明，經(jīng)過土壤活化劑提取后，土壤重金屬直接環(huán)境風險顯著降低，但是潛在環(huán)境風險依然存在。 （3）通過植物生長指標和重金屬累積含量指標評價不同固化劑聯(lián)合植物修復技術的修復效果。所選植被對重金屬均有一定耐受性，植被空間布局合理；六種土壤改良劑方案均能有效促進植物修復，其中雞糞有機肥改良效果優(yōu)于蚯蚓糞有機肥，草木灰和有機肥聯(lián)合使用效果最好。比較外業(yè)實驗設計的幾種土壤改良方案，最優(yōu)的為：在污染土壤上鋪設20cm客土并添加少量石灰速效中和劑，采用草木灰和雞糞有機肥作為固化劑，，該方案有利于植被更好更快定植，進而實現(xiàn)植被對重金屬的穩(wěn)定修復。
[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

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