Selenium Remediation from Aqueous Solution Using Industrial Waste: A Sustainable Approach

Abstract

Selenium contamination is a growing concern worldwide due to its adverse impact on humans and the ecosystem. These pollutants can cause serious health hazards, such as cancer, neurotoxicity, and cardiovascular problems, even at trace doses. Iron-based compounds are becoming increasingly popular among adsorbents because of their remarkable adsorption characteristics and diverse nature. This paper investigated the potential characteristics of waste generated from iron industries for selenium removal from aqueous solutions. The morphological and chemical characteristics were determined by SEM, EDX, XRD, BET, pHzpc, BET, and FTIR. The pHzpc of dolochar (D), iron tailing (IT), and iron slag (IS) are 10.4, 6.5, and 10.7, respectively. The FTIR analysis indicated the presence of different functional groups, such as alcoholic, amide, alkane, and carboxyl groups, which assist in adsorption. The heterogeneity of the adsorbent was observed in XRD analysis. A comparative study on selenium removal efficiency was conducted using a batch study at predetermined parameters. The experiment demonstrated that ~30%, ~91%, and ~93% of the selenium were removed from the aqueous solution by IS, D, and IT, respectively. Iron tailing showed better potential for selenium removal from aqueous solutions than others. Though the surface area of dolochar was higher than others, the presence of iron helped in better adsorption. Thus, the study suggested that iron tailings can be used as a low-cost iron-based adsorbent for selenium removal from different industrial wastewater.