水分和有机物料对土壤锌-镉形态及化学性质的影响

为探求镉-锌复合污染土壤的有效治理途径,通过室内模拟培养试验,在不同水分条件下,运用连续提取法研究草炭和猪粪对土壤锌、镉形态及土壤化学性质的影响。结果表明,草炭和猪粪的施用明显降低了土壤中可交换态锌、镉的含量,增加了铁、锰氧化物结合态锌、镉的含量,随培养时间的增加,影响更显著。其中淹水的效果优于65%相对含水量,猪粪的效果优于草炭。有机结合态锌、镉的含量亦增加,但猪粪处理的增幅小于草炭。不同水分条件下,施用草炭和猪粪对土壤pH值的影响不同,与镉、锌各形态无显著相关性。施用草炭和猪粪增加了土壤无定形氧化铁的含量,其含量与铁锰氧化物结合态锌、镉的含量呈显著正相关关系。

Effects of Water and Organic Materials on Cadmium and Zinc Forms and Chemical Properties in Compound Pollution Soils

In order to seek the effective ways to control the Cd-Zn compound pollution soil,the indoor simulated test were carried out to study the effect of two organic materials(grass charcoal and pig manure)on the forms of Zn,Cd and soil chemical properties.The test performed under two water conditions including submerged and 65% relative water content.The content of exchangeable Zn and Cd in soil decreased remarkably,but the content of FeMnb-Zn,Cd and Ob-Zn,Cd increased after adding organic materials,which was more remarkable with time extending.Pig manure was more effective than grass charcoal.The effect under submerged was better than that under 65% relative water content conditions.Under different water conditions,the effect of adding grass charcoal on pH values was different from that of adding pig manure.The pH value was not related to the contents of Zn,Cd in different forms.The amorphous ferric oxide content increased after adding organic materials,and had an positively significant correlation with FeMnb-Zn,Cd.The effects of water and organic materials on Cd-Zn compound pollution had two respects:on the one hand,Cd and Zn could be bound with organic matters and the availability decreased;on the other hand,the decomposing rate and production of organic materials were different and the basic properties varied with different water conditions.