Herbicide diuron removal from aqueous solution by bottom ash: Kinetics, isotherm, and thermodynamic adsorption studies

The current research reports an efficient methodology of valorizing bottom ash waste generated from the combustion of coal in a local thermal power plant. Where in this work we have used bottom ash waste (BAW-200) as an inexpensive adsorbent for herbicide diuron removal. The BAW-200 was characterized by XRD, FTIR, SEM and mapping analyses. The adsorption kinetics, equilibrium isotherms and regeneration potential of diuron removal by BAW-200 was investigated in batch tests. Pseudo-first order model described well the kinetic data and Langmuir model show a high correlation with equilibrium data, which suggested monolayer adsorption of diuron onto BAW-200 with a higher adsorption capacity (349.52 mg/g) compared to other adsorbents. The thermodynamic behavior revealed that adsorption phenomenon of diuron onto BAW-200 ensued spontaneously and endothermic in nature. The regeneration method show that BAW-200 can be recycled easily from wastewater using ethanol as solvent. The outcomes show that BAW-200 adsorbent could be used in improving the quality of wastewater as providing a waste disposal option for the industry.