Experimental and modelling study of industrial phenolic wastewater treatment by packed bed adsorption on coal-based and bagasse-based fly ash

ABSTRACT Every year nearly 100 million tons of fly ash is being generated in India and its disposing consumes large land volumes. Fly ash can be used as a good adsorbent to clean flue gases as well as wastewater treatment for effluents containing phenolic compounds. In the present work, fly ash from different sources (coal and bagasse based) was evaluated for wastewater treatment. The work involves (i) batch kinetic studies for adsorption of phenols viz. phenol, catechol, resorcinol, hydroquinone, 2-aminophenol and 3-aminophenol, on fly ash; (ii) the effect of initial solute concentration, initial mass of adsorbent, temperature, contact time and pH on removal of phenols from solution; (iii) determination of adsorption isotherm parameters for three isotherm models namely Freundlich, Langmuir and Fritz–Schlunder; and (iv) mathematical model for packed bed adsorption process using fly ash as an adsorbent for industrial-scale capacity (∼10,000 L/day). The results show that bagasse-based fly ash has much more adsorption capacity (∼80% phenol removal) as compared to coal-based fly ash. GRAPHICAL ABSTRACT