Synthesis of bio-based materials from agricultural residues for treatment of petrochemical wastewater

4-Carboxybenzaldehyde (4-CBA), a major component of purified terephthalic acid wastewater, is toxic to living organisms and required to be removed before the discharge of treated wastewater in a natural water body. In this work, the adsorptive removal of 4-CBA was studied using bagasse fly ash (BFA), a waste product from the sugar industry. The adsorption capacity of BFA was compared with the commercially available adsorbent, granular activated carbon (GAC). A 4-factorial, 5-stage central composite design (CCD) was used to optimize 4-CBA removal and adsorption uptake by BFA using response surface methodology (RSM). The variables considered for the study were pH, adsorbent dose ( m ), initial concentration ( C o ) and time ( t ). At the optimum treatment conditions of pH = 4, m = 9 g/L, C o = 100 mg/L and t = 7.5 h, the removal efficiency and adsorption uptake of 4-CBA on BFA were found to be 79