Optimization of Arsenic Adsorption by Mill Scale–Derived Magnetite Particles Using Response Surface Methodology

Abstract This study focuses on the optimization and application of mill scale–derived magnetite particles for the adsorptive removal of arsenic (As) from groundwater. The reverse coprecipitation method is applied to synthesize the magnetite from the mill scale, a byproduct of the iron and steel industry. The independent variables (initial As concentration, pH, contact time, and adsorbent size) affecting the adsorption process were optimized by central composite design of the response surface methodology (RSM). The analysis of variance (ANOVA) results showed that all the independent variables significantly influenced the adsorption capacity. ANOVA analysis exhibited a good fit between the experimental values and the quadratic model predictions, thus resulting in R2 of 0.986. The P-value (