植物处理污泥对华南红壤淋出液重金属的影响

Effect of phyto-treated sewage sludge on heavy metals leaching from red soils of South China

利用2年的盆栽试验,研究了植物处理对污泥农用后华南红壤淋出液重金属的减少效果。设置了对照、无植物污泥处理、单种污泥处理和套种污泥处理。结果表明,不同处理污泥施用于红壤表层后,每次淋出的土壤淋出液中Cu浓度均达到《地表水环境质量标准》(GB 3838—2002)Ⅴ类标准,但Zn、Cd和Pb浓度则不是每次均达到Ⅴ类标准。土壤淋出液中Zn、Cd浓度超出Ⅴ类标准限值时,单种污泥处理对其影响较小,且单种污泥处理土壤淋出液中Zn、Cd浓度分别为无植物污泥处理的12.6%～77.5%和21.5%～53.5%。3个施污泥处理的土壤淋出液中Pb浓度没有明显差异。与无植物污泥处理相比,套种植物处理可以显著降低污泥对土壤淋出液中Zn、Cd、Cu和Pb总量的影响,分别占无植物污泥处理的51.6%、35.4%、51.7%和59.1%,同时显著降低土壤淋出液体积(降低了20.3%);单种植物处理仅显著降低污泥对土壤淋出液中Zn、Cd和Cu总量的影响,分别占无植物污泥处理的51.0%、39.6%、62.8%。

The effects of phyto-treated sewage on heavy metals leaching from red soil （selected from South Chi- na） were studied through 2 years of pot experiments. The control group （with no sludge placed on the red soil） and sludge treatment groups （including no-planting,single-planting and companion-planting treatment group） were set in the experiment. Results showed that after the application of sludge, the concentrations of Cu in red soil leachate all met the Class V of Environmental quality standards for surface water （GB 3838-2002）,however Zn,Cd and Pb could not always met the Class V standard limit value. When Zn and Cd in soil leachate exceed Class V limit value of GB 3838- 2002, single-planting sludge treatment group had relative less effect on Zn and Cd leaching, the concentrations of Zn and Cd in leachate of single-planting sludge treatment group were respectively 12.6%-77.5% and 21.5%-53.5% of no-planting sludge treatment group. There was no significant difference in leachate Pb concentration among the three sludge treatment groups. Compared with no-planting sludge, the companion-planting sludge could obviously decreased the heavy metals leaching, Zn, Cd,Cu and Pb in leachates of companion-planting sludge treatment group were 51.6 %, 35.4% ,51.7% and 59.1% of that in no-planting sludge treatment group, and the total leachates volumes also de- creased by 20.3 %. The single planting sludge could only decrease Zn,Cd and Cu leaching, the content of Zn, Cd and Cu in leachate of single planting sludge treatment group was only 51.0% ,39.6% ,62.8% of no-planting sludge treat- ment group.