3D porous Fe2O3-incorporated basalt filter unit for simultaneous removal of As(III) and As(V) from aqueous solutions: adsorption isotherm and mechanism

The global community is very concerned about the removal of arsenic from contaminated water sources. There is significant global interest in practical methods for the removal of arsenic from polluted water sources. A 3D-porous Fe₂O₃-basalt composite was manufactured by a one-pot solvothermal approach and studied by several methods. The effects of pH, contact duration, adsorption isotherm, and Combodian ground water treatment on removal efficiency were systematically analyzed. The Fe₂O₃-basalt composite demonstrated adsorption capacities of 5.393 mg/g for As(III) and 5.7117 mg/g for As(V) at a neutral pH of 7. Adsorption behavior for both arsenic species aligned closely with the Langmuir isotherm model, while the adsorption isotherm followed a pseudo-second-order model. In Combodian ground water samples, the composite achieved arsenic removal efficiencies of 99.9% for As(III) and 97.3% for As(V), underscoring its potential as an effective adsorbent. Notably, the composite maintained high removal performance over five regeneration cycles, showing robust reusability for both As(III) and As(V) at neutral pH. Sustainability assessments in geothermal water samples confirmed that the Fe₂O₃-basalt composite reliably reduced arsenic levels to meet World Health Organization (WHO) standards for drinking water, supporting its applicability as a sustainable solution for arsenic mitigation in ground water systems.