Unveiling the impact and selectivity of BiVO4/rGO-SiO2 adsorbents for arsenic in ground water: An effective approach for the public safety

Abstract

The presence of arsenic in ground drinking water has become significant threat to the human health. Herein, BiVO₄/rGO-SiO₂ adsorbents have been synthesized and utilized first time for the arsenic contents (As (III) & As (V)) removal. Morphology and optical properties of adsorbents have been demonstrated via XRD, FTIR, SEM, EDX, XPS and UV–Vis/DRS. For the large scale implementation, water samples were collected from the different areas of district Bahawalpur, Pakistan. During the removal process, As (III) was oxidized to As (V) and then subsequently adsorbed on BiVO₄ assisted rGO-SiO₂. Thermodynamic and kinetic studies exhibited a higher fitting Langmuir isotherm (R² = 0.99) and pseudo-second order (R² = 0.99) respectively. It has been predicted that adsorption of arsenic is an endothermic process that has ΔH° = 49.18 KJ/mol and negative ΔG° = –1.86801 kJ/mol value. It has been estimated that 10 g of adsorbent is sufficient to remove 99.9 % of arsenic contents. On the basis of results, it has been justified that this work holds promise to replace the conventional adsorbents to get arsenic free water.