Polysaccharide-derived hydrogel water filter for the rapid and selective removal of arsenic

Abstract

A low-cost furfuraldehyde–chitosan cross-linked hydrogel (FCH) has been designed and synthesized as a smart bio-adsorbent for the selective removal of As(V) from an aqueous solution using a solid liquid extraction (SLX) technique. The adsorption behavior of the FCH towards As(V) has been thoroughly investigated and the parameters such as pH, amount of cross-linking agent, time of contact and weight of the hydrogel have been optimized. The adsorption kinetics of the FCH for As(V) followed a pseudo-second-order model with an initial adsorption rate of 0.1479 g mg⁻¹ min⁻¹. 0.5 M HNO₃ was used as the efficient eluent to desorb As(V) without noticeable loss of the adsorption capacity of the FCH for As(V) after a few repeated adsorption/desorption cycles. This hydrogel is also effective for the economically viable, rapid and selective removal of arsenic from groundwater.