Asenic removal from groundwater using granular chitosan-titanium adsorbent

摘要

Arsenic(As)contamination poses an urgent environmental risk,and its removal from groundwater remains a challenge due to the lack of efficient adsorbents.Herein,a novel granular chitosan-titanium(CS-Ti)adsorbent was fabricated by the sol-gel method.Batch experiments show that As(V)adsorption on CS-Ti followed the pseudo-second-order kinetic model,and the adsorption isotherm conformed to the Freundlich model with the correlation coefficient of 0.99.In situ FTIR spectra revealed that the CS-Ti adsorbent was composed of amorphous TiO_(x) and chitosan by forming C-O-Ti and N-Ti bonds,and the amorphous TiO_(x) was responsible for As(V)adsorption.Rapid small-scale column tests show that 165.6μg/L of As in groundwater were effectively removed in approximately 126-bed volumes,and the spent adsorbents were regenerated with 0.01 mol/L Na OH and maintained the adsorption efficiency after four cycles.This study provides a simple and practical route to fabricate adsorbents for water treatment.