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

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 con-sumption. 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 mu 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 mu g g(-1), after 2 h) for As(V) at neutral pH. Adsorption process mainly followed pseudo-second-order kinetics and Freundlich isotherm models (R-2-0.90) 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.

Automated summary

This study focuses on the removal of arsenate from groundwater using bilayer-oleic coated iron-oxide nanoparticles. The adsorbent showed efficient removal of arsenate at neutral pH, following pseudo-second-order kinetics and Freundlich isotherm models. Regeneration and competition studies supported the potential field application of the proposed adsorbent.