Study on effect of heavy metal and rare earth metal on soil activities

摘要

In recent years, as public awareness on environmental problems increasing, soil pollutions are received more and more attention. Choosing a suburban garden soil as objective, adding exogenous heavy metal cadmium (Cd) and rare-earth element lanthanide (La) in the soil, Cd/La single stress and combined stress on soil urease and catalase were studied. The results showed that under Cd/La single or combined processing, both soil urease and catalase activities decrease while the concentration increases. With the incubation time extending, soil urease activities first increase and then decrease, and soil catalase first reduce then increase. Cd/La single and combined process has obvious inhibition on soil urease and catalase. At the same concentration, the inhibition degree to enzyme activity was Cd>Cd, La combined> La, and the inhibition of soil urease was higher than that of catalase. Soil urease and catalase showed a significantly negative correlation under different treatments. So setting soil urease and catalase as ecological indicators to soil heavy metal and rare earth elements pollution is feasible.