Optimization of adsorption process by aluminum dross for treatment of cutting oil wastewater

Abstract

This research employed untreated aluminum dross obtained from auto parts manufacturing waste as an adsorbent to meet the sustainable goals of waste utilization in readily available, inexpensive, and environmentally friendly materials to treat cutting oil wastewater in auto parts manufacturing. Aluminum dross, categorized as white dross with 37.13% aluminum and 7.77% silicon, is a source of silicon-and aluminum-containing wastes. Process optimization was conducted using a central composite rotary design (CCRD) coupled with response surface methodology (RSM). The results indicated that the adsorption of aluminum dross at optimum conditions was 15 g adsorbed from 1% v/v cutting oil wastewater at pH 2 in 60 minutes, achieving the removal efficiency at 93.30% of chemical oxygen demand (COD), 88.33% of turbidity, and only 40.47% of total organic carbon (TOC). The second-order equation demonstrated coefficients of determination (R 2 ) and adjusted R 2 values of 0.9738 and 0.9345, respectively, for COD removal. The COD adsorbed on aluminum dross could be adequately explained using the pseudo -secondorder kinetic and Langmuir models. Aluminum dross adsorption for cutting oil treatment has a low operating cost of 0.5398 USD/m 3 .