Batch experiments on arsenic removal efficiencies through adsorption using synthetic and natural sand samples

Abstract

Recently it has been unearthed that many potable water sources around the world are contaminated with arsenic, which has got long-term health hazards for the consumers. Among different arsenic removal techniques, adsorption is widely used and easily achievable. Through the use of suitable adsorbent, arsenic can be significantly removed from potable water, which is a dire need for many distant communities where there is scarcity of alternative potable water source. This paper presents arsenic removal characteristics of different synthetic and natural sand samples through adsorption. To replicate the Skye sand which was found to be effective in removing arsenic, two synthetic sand samples (one coated with iron and the other coated with aluminium) were prepared in the laboratory. Different combinations of these samples were tested through batch experiments to evaluate their arsenic removal efficiencies under different conditions. It is found that among the synthetic adsorbents, the ones dried at 80 °C (during their preparation) showed the highest arsenic removal efficiencies. Also, among all the samples, iron oxide-coated sand (IOCS) showed the highest arsenic removal efficiencies, varying from 71 to 100% depending on the amount of doses, whereas with the use of natural Skye sand with the same variation in doses, arsenic removal efficiencies varied from 26 to 90%.