Environmental Impacts of Coal Ash from a Power Plant

Abstract

This paper presents a investigation of pollution originating from coal ash in Jingangshan thermal power station Jiangxi province China. About half of coal ash obtained by coal combustion in the power plant is mixed with ash-flushing water (most of the ash-flushing water from Ganjiang river) and transported to the ash field through the pipeline. In order to assess pollution caused by leaching of some minor and major elements after ash being transported to the ash field, two kinds of samples were subjected to a modified sequential extraction experiment. The first set consisted of coal ash samples taken after combustion, while the second kinds of samples were obtained from the the ash field. Samples were extracted consecutively with distilled water, a solution of potassium chloride and a solution of hydrochloric acid, the differences were compared in order to predict potential pollution. Considering concentrations of seven trace elements as well as five major elements in extracts from a total of 12 samples, it can be concluded that lead and cadmium do not present an environmental threat after coal ash being transported to the dump. Portions of zinc, nickel and chromium are released, and arsenic and manganese are released continuously. Copper and iron do not present an environmental threat due to element leaching during and after the coal ash suspension and transport. On the contrary, these elements of chromium become concentrated.