摘要
采用填充土柱淋溶试验研究不同pH值模拟酸雨和海泡石添加量对重金属污染红壤Cd、Pb淋溶的影响。结果表明,Cd在酸雨pH值较低时累积淋溶量较大,Pb的累积淋溶量随酸雨pH值的降低逐渐增加,pH值为3.5处理的Pb总累积淋溶量显著高于其他pH值处理(高出54.9%)。与对照相比,模拟酸雨pH值为3.5时,添加5g/kg和10g/kg海泡石处理Cd的总累积淋溶量明显增加(分别增加24.6%和26.3%),而Pb的总累积淋溶量分别显著降低34.7%和25.7%;酸雨pH值为4.5时,添加5g/kg和10g/kg海泡石处理降低了Cd的累积淋溶量(分别降低13.0%和1.4%),而Pb的淋溶量随海泡石添加量的增加而降低,10g/kg海泡石处理的Pb总累积淋溶量显著下降17.6%;pH值为5.5和6.5时,海泡石处理Cd累积淋溶量均有所下降,而对Pb的淋溶无显著降低效果。酸雨酸性强度的增大增加了Cd、Pb的淋溶风险,且Pb比Cd敏感。添加海泡石可有效减少酸雨对土壤中Pb的淋溶,但其对Cd淋溶的影响受酸雨酸性强度的影响。
By using soil column leaching experiment,the effects of acid rain pH and sepiolite addition on Cd and Pb leaching in a contaminated red soil were studied.The results indicated that the accumulation leaching amount of Cd reached the highest at lower pH values.The accumulation leaching amount of Pb increased with decreasing pH values.The accumulation leaching amount of Pb reached the highest,and it was higher than those of other treatments by 54.9%.When the acid rain pH value was 3.5,compared with the CK treatment,after additions of 5 g/kg and 10 g/kg sepiolite,there was a significant increase in accumulation leaching amount of Cd by 24.6% and 26.3%.While a significant decrease in accumulation leaching amount of Pb by 34.7% and 25.7% was detected when the acid rain pH value was 3.5.When the acid rain pH value was 4.5,addition of 5 g/kg and 10 g/kg sepiolite reduced the accumulation leaching amount of Cd by 13.0% and 1.4%.While the accumulation leaching amount of Pb gradually decreased with increasing amount of sepiolite by 17.6% at S10 treatment.After additions of sepiolite,accumulation leaching amount of Cd decreased,but accumulation leaching amount of Pd had no changes when pH value was 5.5 and 6.5.Therefore,the intensity of acid rain could enhance the risk of leaching Cd and Pb in red soil,and Pb was more sensitive than Cd.The leaching of Pb could be effectively controlled by applying sepiolite into contaminated red soil under acid rain conditions,while the effects of sepiolite on Cd leaching was impacted by the pH of acid rain.
出处
《水土保持学报》
CSCD
北大核心
2013年第3期23-27,共5页
Journal of Soil and Water Conservation
基金
国家科技支撑计划项目(2012BAD05B06)
湖南省科技重大专项(2011FJ1002-3)
国家自然科学基金项目(41101300)
中科院知识创新领域前沿项目(ISACX-LYQY-QN-1204)
关键词
模拟酸雨
海泡石
红壤
土柱
Cd和Pb
淋溶
simulated acid rain
sepiolite
red soil
soil column
Cd and Pb
leaching
