Treatment of Simulated Dumpsite Leachate Using Fly Ash in the Constructed Wetland

Fly ash is the primary residue produced in huge amounts by coal combustion in thermal power plants, which needs to be utilized appropriately. In this connection, an experimental study was conducted with fly ash alone and in combination with soil for the treatment of simulated dumpsite leachate in constructed wetland (CW) (vertical flow) systems containing Canna + Typha plants. The study revealed that the fly ash + soil mixture as a CW substrate showed better removal efficiency of chemical oxygen demand (COD), phosphate ( \({\text{PO}}_{4}^{{3 - }}\) ), total nitrogen (TN), and chloride (Cl^–) by 97.3, 99.4, 94.5, and 89.6%, respectively, in comparison to the fly ash alone which was shown to yield the corresponding values of 88.5, 94.1, 84, and 73.2% of the efficiency in the removal of these pollutants from simulated dumpsite leachate.