Leaching studies of pulverised fuel ash from coal-based thermal power plant and its environmental impact

Abstract

The major by-product of coal-fired thermal power plants is pulverised fuel ash (PFA) and the common method of disposal of PFA is wet disposal method. In this method, PFA and bottom ashes are mixed with water, which made them slurry, and are disposed in ash pond or lagoons. If the lagoons are not properly designed with liner or if there is spillage from the lagoons, the toxic heavy metals present in the PFA can contaminate soil or ground water. Hence, this study concentrates on the leaching of PFA sample collected from Malaysia. The leachability of PFA was investigated by column model with different liquid-to-solid (L/S) ratio and pH values. It was found that the concentration of trace elements increases with the increase in acidity and decreases with higher L/S ratio. Also, some trace elements exceeded the standards set by The Ministry of Health Malaysia, hence are hazardous to the environment.