Magnetite nanoparticles coated sand for arsenic removal from drinking water

In this paper, for the first time we describe the removal of poisonous element 'arsenic (V)' from drinking water by nanoscale magnetite coated sand. The removal efficiency of newly formed adsorbent was studied by varying various parameters, for example, contact time, pH, adsorbent dosage and initial As(V) concentration. Also, the experiments were performed in the presence of co-existing cations (Zn2+, Cd2+, Pb2+, Ni2+, Mg2+, Cr3+ and Fe3+) to study their influence on As(V) removal efficiency. The adsorption kinetics data fitted well in both the pseudo-first-order and pseudo-second-order kinetics with high correlation coefficients (R-2 > 0.99). Adsorption isotherm data are fitted in Langmuir and Freundlich isotherm models. It is observed that thus formed adsorbent shows significant As(V) removal efficiency, and reduces the As(V) concentration below 5 mu g/L from 6700 mu g/L, which is much less than the maximum contaminant level set by WHO (10 mu g/L). Here, the co-existing cations do not show any significant effect on As(V) removal efficiency. The observed Freundlich adsorption capacity of 2.06 mg/g for As(V) removal is comparable with certain other adsorbents.