Studies on Stability of ¹⁰⁹Cd, ⁶⁵Zn Complex with Humus Acids

【作者】 华珞；

【Author】 HUA Luo, CHEN Shi-bao, BAI Lin-gyu, WEI Dong-pu(Capital Normal University, Geography . Department Beijing, 100037)(Institute for Application of Atomic Energy, CAAS, 100094)

【机构】 首都师范大学资源环境旅游学院；

【摘要】 <正> The radioactive isotope tracer and ion exchange balanced method was used to study the stability of 109Cd, 65Zn complexes with humus acids. In the 109Cd and 65Zn single existing system with humic acids, the stability constants of humic-109Cd(65Zn) complex compound was higher than fuIvic-109Cd65Zn) complex compound. The stability constant of humic (fulvic) -65Zn was higher than that of humic (fulvic) -109Cd. In 109Cd and 65Zn coexisting system, stability constant and co-ordination number of humic (fulvic)-65Zn complex obviously increased, but stability constant and co-ordination number of humic (fuIvic)-109Cd complex obviously decreased. The result showed that the humus matter with higher molecular weight could more effectively reduce plant availability of heavy metals than the humus matter with lower molecular weight in polluted soil, and that humus matter could more effectively reduce plant availability of Zn than that of Cd. Application of humus-acid increased harm of Cd and decreased harm of Zn to plant with Cd-Zn coexisting.更多还原

【Abstract】 The radioactive isotope tracer and ion exchange balanced method was used to study the stability of 109Cd, 65Zn complexes with humus acids. In the 109Cd and 65Zn single existing system with humic acids, the stability constants of humic-109Cd(65Zn) complex compound was higher than fuIvic-109Cd65Zn) complex compound. The stability constant of humic (fulvic) -65Zn was higher than that of humic (fulvic) -109Cd. In 109Cd and 65Zn coexisting system, stability constant and co-ordination number of humic (fulvic)-65Zn complex obviously increased, but stability constant and co-ordination number of humic (fuIvic)-109Cd complex obviously decreased. The result showed that the humus matter with higher molecular weight could more effectively reduce plant availability of heavy metals than the humus matter with lower molecular weight in polluted soil, and that humus matter could more effectively reduce plant availability of Zn than that of Cd. Application of humus-acid increased harm of Cd and decreased harm of Zn to plant with Cd-Zn coexisting.更多还原