土壤溶液动态变化和CdCO3, CdS的平衡研究

土壤渍水后带来了一系列的电化学和化学变化,pH、氧化还原电位(Eh)、电导(EC)、离子交换、吸附和解吸、化学动力学和化学平衡等都有着显著的改变^9,11,13],它们影响着土壤肥力状况和植物对毒性元素的吸收。本文报道了在添加Cd,P,Zn化合物的情况下土壤溶液动态变化和CdCO₃,CdS平衡研究的结果。

STUDIES ON KINETICS AND EQUILIBRIA OF CdCO3 AND CdS IN SOIL SOLUTION

Some chemical and eletrochemical kinetics and the equilibria of CdCO₃ and CdS in soil solution were investigated under the condition of additional Cd,P and Zn compounds.Suhmergence brought about a series of physicochemical and chemical changes that markedly influenced the pH,Eh,EC,Es,chemical kinetics and mineral equilibrium in paddy soils.The pH of soil solution gradually increased while Eh decreased with the time of soil flooding.Some of Cd treatments decreased Eh.The maximum EC value reached at 4th week after flooding and then declined gradually.The concentrations of NH₄⁺-N,K,Ca,Mg,Fe and Mn in soil solution increased markedly during first 2 to 4 weeks after flooding,while those of Zn and P were getting decreased.A study of CdCO₃ and CdS equilibria by means of IAP method showed that there might be CdS present in the soil after 5 weeks of submergence.But results gave no thermodynamic evidence fur CdCO₃ existence.