施用垃圾堆肥土壤重金属在不同温度和酸雨条件下的淋溶特征

采用淋洗法,研究了垃圾堆肥中重金属在不同温度与模拟酸雨条件下的淋溶特征。结果表明,随着淋洗次数的增加,淋洗液中Cd、Cr、Cu、Ni和Pb的含量都有很大程度的减少。Cd、Cr、Cu和Ni 4种金属在模拟酸雨的情况下淋出量明显高于蒸馏水的情况,增幅都在116%和351%之间,差异显著(P<0.05)或极显著(P<0.01),而酸雨对Pb的淋出影响较小。在酸雨淋洗下,重金属的淋出率在30℃时达到最大,其中Ni随着温度的变化相对较小。而在蒸馏水淋洗下,重金属的淋出率随着温度的变化相对平稳。此外,5种重金属的淋出率明显不同,其中Cr和Ni的淋出率相对较大,Pb最小。

Leaching characteristics of MSW compost heavy metals in soil under different temperatures and simulated acid rain

A column experiment was performed to investigate the leaching characteristics of heavy metals of MSW compost in the soil under different temperatures and simulated acid rain.The results showed that the contents of Cd,Cr,Cu,Ni and Pb in the leachates decreased with leaching time.Simulated acid rain was more efficient than distilled water to enhance the leaching of Cd,Cr,Cu,and Ni,and increased by 116% to 351%,with significant(P<0.05) or very significant(P<0.01) differences.However,the application of simulated acid rain had little effect on Pb.The leaching rate of heavy metals was maximum at about 30 ℃ when leached by simulated acid rain,while Ni changed little with temperatures.When leached by distilled water,the leaching rate of heavy metals were little changed with temperatures.In addition,the leaching rates varied with 5 heavy metals,Cr and Ni were relatively large,Pb was minimum.