酸雨对长江三角洲地区四种典型土壤中锌解吸的影响

近年来酸雨危害频繁发生,特别是长江三角洲地区,酸雨致使土壤中重金属锌的吸附和解吸发生了一定的变化。选取具有代表性的长江三角洲地区4种典型土壤,通过加入外源重金属锌培育污染土样,在不同pH的酸雨下对已污染土样进行解吸。通过实验探究土壤母质对于重金属锌的吸附及解吸的特点,为国家制定土壤标准提供可靠的数据支持。结果表明：土壤中锌的解吸量随着pH的降低而增加;比较不同母质发育而成的土壤,在pH=4.0、5.6模拟已污染土壤中锌的解吸量顺序为：沟沟堆积母质〉湖相沉积物母质〉河相沉积物母质〉海相沉积物母质。在pH=2.0、3.0时,河相沉积物母质、湖相沉积物母质解吸量迅速增加,超过海相沉积物母质锌的解吸量。

Research on desorption of zinc by acid rain in the different parent material soils of Yangtze River Delta

In recent year,the absorption and desorption of zinc changed in soil because of the frequent acid rain,especially in the Yangtze River Delta region.Four typical soils in the Yangtze River Delta region were selected in the research.The soils were polluted by adding exogenous zinc contamination,and then desorbed by acid rain with different pH.The characteristics of zinc absorption and desorption were studied to provide reliable data support for the formulating of the soil standard of state.The results showed that：the desorption of zinc in soil increased with the decrease of pH.For different parent material soils,the desorption of zinc by acid rain when pH was 4.0 or 5.6 followed the order：Gully accumulation lake sediment river sediment sea sediment.In river sediment and lake sediment,the desorption of zinc by acid rain of pH 2.0 or 3.0 increased rapidly,and were higher than in sea sediment.