Assessment of ecotoxicity of tellurium in soils of contrasting properties

The ecotoxicity of tellurium(Te)compounds(oxide and nitrate)is assessed by changing the biological properties of soils of contrasting properties:Haplic Chernozem(Loamic),Eutric Cambisol,and Eutric Arenosol.Soil stability was assessed by the most sensitive and informative biological indicators:microbiological(total number of bacteria),biochemical(catalase and dehydrogenase activity),and phytotoxic(changes in the length of wheat roots and shoots).Te contamination was simulated at concentrations of 0.5,1,3,10,and 30 possible permissible concentrations(PPC).It has been established that already at minimum concentrations of Te(0.5 and 1 PPC),the biological indicators of soils decrease.As a rule,a direct relationship between Te concentration and the degree of deterioration of the studied soil properties was observed.Te nitrate showed higher ecotoxicity than oxide.A stronger negative effect of Te contamination was manifested 10 and 30 days after contamination.After 90 days,the restoration of the biological properties of the soils was observed.Haplic Chernozem(Loamic)showed greater resistance to Te contamination than Haplic Cambisols Eutric and Eutric Arenosol.The obtained results can be used to predict environmental risks from soil contamination with Te and to develop maximum permissible concentrations of Te in soils of contrasting properties.