Removal of Arsenic from Groundwater Using Iron-Coated Sand in Rapid Gravity Filtration Systems

Abstract

Arsenic contamination in groundwater represents a serious environmental and public health concern due to its toxic and carcinogenic effects on human populations exposed through drinking water supplies. The present study investigates the removal of arsenic from groundwater using iron-coated sand in rapid gravity filtration systems under controlled treatment conditions. The research focuses on evaluating the adsorption efficiency, filtration performance, operational stability, and process optimization associated with iron-coated filtration media for arsenic removal. Experimental analysis was conducted to determine the influence of influent arsenic concentration, pH, filtration rate, contact time, iron coating characteristics, and competing ions on treatment efficiency and filter performance. Results demonstrate that iron-coated sand significantly enhances arsenic adsorption through surface complexation and precipitation mechanisms, resulting in substantial reductions in dissolved arsenic concentrations. The study further reveals that optimized filtration conditions improve contaminant removal efficiency while maintaining acceptable hydraulic performance and reduced head loss development within the filtration system. The presence of iron oxide active sites was found to promote strong affinity toward both arsenite and arsenate species, contributing to stable long-term removal performance. Comparative assessment with conventional groundwater treatment methods confirms that iron-coated sand filtration offers advantages including low operational cost, simplified maintenance, and suitability for decentralized water treatment applications. In addition, the system demonstrates potential for sustainable implementation in arsenic-affected rural and urban regions with limited access to advanced treatment infrastructure.