Geogenic arsenic removal through core�shell based functionalized nanoparticles: groundwater in-situ treatment perspective in the post�COVID anthropocene

Abstract

Groundwater, one of the significant potable water resources of the geological epoch is certainly contaminated with class I human carcinogenic metalloid of pnictogen family which delimiting its usability for human consumption. Hence, this study concerns with the elimination of arsenate (As(V)) from groundwater using bilayer�oleic coated iron�oxide nanoparticles (bilayer�OA@FeO NPs). The functionalized (with high�affinity carboxyl groups) adsorbent was characterized using the state�of�the�art techniques in order to understand the structural arrangement. The major emphasis was to examine the effects of pH (5.0�13), contact times (0�120 min), initial concentrations (10�150 ?g L�1), adsorbent dosages (0.1�3 g L�1), and co�existing anions in order to understand the optimal experimental conditions for the effective removal process. The adsorbent had better adsorption efficiency (? 32.8 ?g g�1, after 2 h) for As(V) at neutral pH. Adsorption process mainly followed pseudo�second�order kinetics and Freundlich isotherm models (R2?0.90) and was facilitated by coulombic, charge�dipole and surface complexation interactions. The regeneration (upto five cycles with 0.1 M NaOH) and competition studies (with binary and cocktail mixture of co�anions) supported the potential field application of the proposed adsorbent.