A suspended adsorbent filter for arsenic removal from water to address UN 2030 agenda for sustainable development

Magnetite particles are widely recognized as green and sustainable material for advanced water treatment. The magnetite particles are synthesized through a simple electrochemical process at room temperature from an iron-based electrode immersed in an alkaline aqueous medium at pH 10.5. Arsenic adsorption kinetics were rapid, and adsorption reaction can reach equilibrium within 10 minutes following a pseudo-second-order rate expression with observed reaction rate constants of 0.029 and 0.017 gmg-1min-1 for As(III) and As(V), respectively. Magnetite exhibited high adsorption capacity; the equilibrium adsorption capacity of 86.2 and 113.6 mg/gm of magnetite were observed for As(III) and As(V), respectively, at pH 7.0. From Freundlich isotherm, the adsorption intensity parameters for As(III) and As(V) are 0.75 and 0.85, indicating a spontaneous and favorable adsorption of arsenic on magnetite. These results suggest that magnetite can serve as a highly effective adsorbent for fast removal of arsenic and more appealing for decentralized water treatment such as suspended adsorbent filter at the household or community level. The filter could be a sustainable solution offering environmental remediation to achieve the United Nation’s sustainable development goals.