Adsorption of 2-picoline from wastewater by agro coal ash: parametric, kinetic, equilibrium and thermodynamic features

Abstract

2-Picoline is a derivative of pyridine. Due to the hazardous nature, the removal of 2-picoline from wastewater is important. In the present study, the ability of agro coal ash as an adsorbent for the removal of 2-picoline from wastewater in a broad range of concentration (50–300 mg/L) was investigated. The influence of various experimental parameters like initial pH, adsorbent dose, contact time, initial concentration and temperature on the removal of 2-picoline on agro coal ash were studied. The optimum conditions for the maximum removal of 2-picoline were found to be: initial pH 6, contact time = 7 h and adsorbent dose = 2 g/L. Adsorption of 2-picoline followed pseudo-second-order rate kinetics. The Langmuir and Freundlich adsorption equilibrium isotherm models were analysed. The values of the change in Gibb’s free energy (DG), enthalpy (DH) and entropy (DS) were calculated. Thermodynamic studies revealed that adsorption of 2-picoline on agro coal ash is an endothermic process.