不同有机废弃物对铅锌尾矿基质性质和植物生长的影响

Effects of different organic wastes on plant growth and tailings properties of a Pb-Zn mine

为研究有机废弃物作为改良剂对铅锌尾矿污染基质修复效果的影响,采用原位基质改良方法,开展野外田间试验,研究不同处理对尾矿基质营养元素、DTPA提取态重金属、酶活性以及植被盖度、生物量、植物体内重金属含量的影响。结果表明,尾矿基质的营养元素、酶活性以及植被盖度、生物量均最低,而尾矿基质DTPA提取态重金属、植物体内重金属最高;与尾矿相比,添加不同有机废弃物后尾矿基质有机质、有效磷、铵态氮、有效钾含量分别增加了0.68~5.52、1.50~14.46、1.62~4.59、0.16~1.08倍;尾矿基质DTPA-Cd、DTPA-Cu、DTPA-Pb、DTPA-Zn分别降低了27.33%~62.06%、6.98%~35.19%、0.50%~32.41%、19.37%~43.98%;尾矿基质脱氢酶、葡萄糖苷酶、脲酶、磷酸酶分别增加了0.08~11.00、0.05~1.72、0.59~17.38、1.71~6.74倍;植被盖度、生物量分别增加了12.75~84.75、1.59~215.57倍;植物体内Cd、Cu、Pb、Zn分别降低了23.18%~82.76%、3.30%~39.52%、67.30%~81.46%、44.98%~75.60%;总体上鸡粪组、污泥组提升尾矿基质营养元素、酶活性以及植被盖度、生物量效果最明显,且均达到显著水平(P<0.05)。其中鸡粪组有机质、有效磷、有效钾分别增加了5.52、14.46、1.08倍,污泥组铵态氮增加了4.59倍;鸡粪组、污泥组脱氢酶分别提高了11.00、10.12倍,脲酶分别提高了17.38、16.74倍,磷酸酶分别提高了6.74、5.94倍;鸡粪组、污泥组生物量分别增加了214.80、215.57倍,植被盖度分别增加了84.75、80.25倍。8种有机废弃物均有助于植物在铅锌尾矿基质上的定居与生长,其中鸡粪、污泥在尾矿基质的改良实践中具有较大的修复潜力。

The effects of different organic wastes to amend the physio-chemical properties of Pb-Zn mine tailings were studied.A field experiment was conducted on Pb-Zn mine tailings to evaluate the efficiency of different treatments on nutrients,diethylene-triaminepentaacetic acid(DTPA)-extracted heavy metal,enzyme activity,plant biomass and coverage,and heavy metal content in plants.The principal findings were as follows:the mine tailings had the lowest nutrient elements,enzyme activity,vegetation coverage,and biomass,whereas the DTPA-extracted heavy metal in the tailings and the heavy metal content in plants were the highest.The application of different organic wastes significantly increased the organic matter content,available phosphorus,ammonium nitrogen,and available potassium,which were 0.68~5.52,1.50~14.46,1.62~4.59,and 0.16~1.08 times higher,respectively,than those in the tailings.Compared with the tailings,the DTPA-Cd,DTPA-Cu,DTPA-Pb,and DTPA-Zn concentrations in organic waste-amended plots decreased by 27.33%~62.06%,6.98%~35.19%,0.50%~32.41%,and 19.37%~43.98%,respectively.Dehydrogenase,glucosidase,urease,and phosphatase increased by 0.08~11.00,0.05~1.72,0.59~17.38,and 1.71~6.74 times,respectively.Plant biomass and coverage increased by 1.59~215.57 and 12.75~84.75 times,respectively.Cd,Cu,Pb,and Zn in plants decreased by 23.18%~82.76%,3.30%~39.52%,67.30%~81.46%,and 44.98%~75.60%,respectively.Chicken manure and municipal sludge had the highest effect on nutrient elements,dehydrogenase,urease and phosphatase activity,and plant biomass and coverage with a significance level of P<0.05.Organic matter and available phosphorus and potassium in the chicken manure-amended plots increased by 5.52,14.46,and 1.08 times,respectively,and ammonium nitrogen in the municipal sludge-amended plots increased by 4.59 times.Dehydrogenase,urease,and phosphatase in the chicken manure-amended and municipal sludge-amended plots increased by 11.00 and 10.12,17.38 and 16.74,and 6.74 and 5.94 times,respectively.The plant biomass and coverage of the chicken manure-amended and municipal sludge-amended plots increased by 214.80 and 215.57,84.75 and 80.25 times,respectively.Overall,these eight organic wastes favor plant survival and growth.The chicken manureamended and municipal sludge-amended plots have potential to greatly improve Pb-Zn mine tailing practices.