Treatment of refinery waste water using modified sludge—Effect of processparameters, sorbent characterization and kinetic studies

AbstractThis research study focuses on the feasibility of the application of modified activated sludge as an adsorbent to treat refinery effluent was tested at different conditions. The sorbent was characterized using Fourier transform infrared spectroscopy and scanning electron microscope analysis. Maximum chemical oxygen demand (COD) removal of 84% was observed at pH 8.0, sorbent dosage 8 g L−1, temperature 35°C shaking speed 300 rpm and initial COD 3,400 mg L−1. Experimental data were analyzed using pseudo-second-order, power function, and Elovich kinetic models to identify the mechanism of COD removal. Pseudo-second-order model was found to represent the COD removal kinetics very well and the kinetic constant was estimated as 0.7 × 10−4 g mg−1 min−1 with the actual effluent. Maximum COD uptake of 153.846 mg g−1 was observed in this study.