Adsorption of lead (Pb2+) onto salicylic acid-methanol modified steel slag from aqueous solution: A cost analysis

Abstract

Industrial wastewater contaminated with heavy metals is a major environmental and health hazard that can be effectively treated by the absorption process. In this regard, steel slag is a low-cost product used to produce unconventional adsorbents. The present study investigated the applicability of salicylic acid-methanol modified steel slag in the adsorption of lead (Pb2+) ion from aqueous solution. Brunauer–Emmett–Teller, scanning electron microscopy, Fourier-transform infrared spec-troscopy, and pHZPC were employed to characterize the synthesized adsorbent. The effects of parameters such as pH, initial concentration, and adsorbent dosage on the adsorption of Pb2+ were further examined. With raising the initial concentration of Pb2+ to 200.0 mg mL–1, the adsorption capacity increased and then became stable. The increase in adsorbent dosage reduced the adsorption capacity and augmented the removal efficiency. Langmuir isotherm model with R2 = 0.9912 fitted well with the experimental data, and its qmax was 117.6 mg g–1 at pH 7.0. The adsorption process obeyed pseudo-second-order kinetics.