Occurrence Form and Ecological Effect of Selenium in Soil and Surface Water of Kailuan Coalfield of Tangshan

Mining induced generally adverse effect to the environmental ecosystems.This paper studied the beneficial element Se produced in the process of coal mining and burning.The occurrence form of Se in soil and surface water influx into the mine water and the enrichment of Se by crops such as wheat,maize and rice were analyzed.The results indicated that organic and residual forms are the dominant forms of Se in soil,with the soluble form accounting for only 1%.Se4+ and Se6+ accounted for 23.89% and 32.99% in total soluble Se in soil,respectively.In the surface water influx into the mine water,the percentages were 37.78% and 40.24%,respectively.The mean contents of Se in wheat,maize and rice were 0.169 mg·kg-1,0.094 mg·kg-1 and 0.26 mg·kg-1,respectively.Rice was irrigated using the mine water,which did not only solve the problem of waste water,but also produced Se-enriched rice,moreover,the contents of deleterious elements were not high.Therefore,making full use of the Se-enriched resource in the mining area would weaken the adverse effect of mining.