Characterisation of coal fly ash for potential wastewater treatment opportunities

Abstract

Lakvijaya coal power plant, which is in Norochcholai, Puttalam District, Sri Lanka, is the largest coal power plant in Sri Lanka. It annually produces about 150,000 tonnes of fly ash (FA) as waste, and the management of it is a pressing concern. Various studies have been conducted to valorise FA in a useful manner without simply dumping it into the nearby lands. To this end, we propose the utilisation of FA in wastewater treatments to adsorb heavy metal ions in wastewater to promote environmental sustainability. The direct application of FA for that purpose may be questionable due to the contaminants present in the FA; however, it is reported commercially. Therefore, we attempt to initiate a preprocessed preparation route to ensure the leachate contains fewer contaminants compared to the use of raw FA. Washing is a commonly used preliminary pre-processing step, though it is not studied extensively in the literature with reference to the FA. Herein, we aimed to study the effects of the number of washing cycles and temperature on the characteristics of the FA. With the results, we could conclude that washing is an effective means of preprocessing to alleviate the contaminants of FA, en route for wastewater treatment.