外源镉铅铜锌在土壤中形态分布特性及改性剂的影响

Distribution of Forms for Cadmium,Lead,Copper and Zinc in Soil and Its In fluences by Modifier

采用盆栽、田间试验及连续浸提分组方法,研究了外源Cd、Pb、Cu、Zn在土壤中的形态分布规律及石灰+钙镁磷肥施用对重金属形态分布的影响。研究结果表明,原状土中Cd主要以有机结合态为主,外源Cd污染土主要以残渣态和交换态为主。原状土中Pb、Cu、Zn主要以残渣态为主,而外源重金属Pb、Cu、Zn在土壤中主要以铁锰氧化物结合态为主。外源重金属土+石灰和钙镁磷肥后使土壤中的交换态Cd、Pb、Cu、Zn下降,而碳酸盐结合态Cd、Pb、Cu、Zn含量增加。pH提高,使土壤重金属的有效态含量下降,pH降低使重金属有效态含量增加。

An investigation,consisting of se quential extraction fractionation,field and pot experiments,was undertaken to study the form distributions of Cd,Pb,Cu,and Zn in soil and effective lime +Ca,Mg,P fertilizer on Cd,Pb,Cu,Zn form dis tribution in soil.The result showed that Cd of original soil mainly existed in organic matter as bound form,while exotic Cd of soil was found predominantly in residual fraction and exchangeable forms,Pb,Cu,Zn of original soil mainly existed in residual fraction,exotic Pb,Cu,Zn of soil was found predominantly in Fe and Mn -oxides bound forms.The treatment of lime +Ca,Mg,P fertiliz er decreased Cd,Pb,Cu,Zn contents of exchangeab le forms in soil,but it increased Cd,Pb,Cu,Zn contents of carbonate form s in the soil.The available contents of heavy metals i ncreased with decreasing soil pH,it decreased with increasing soil pH.