Potential of community prepared wooden charcoal of Assam (India) for As(III) removal through batch and continuous column studies

Abstract

Groundwater is the main source of domestic water for the rural population of Assam, India, which contains arsenic (As(III)) in the range 50–200 μg L−1. The people use variants of indigenous household iron filter units fabricated using community prepared wooden charcoal (CPWC) as one of the filtering medium to remove excess concentration of Fe(II), but no efforts are made to reduce As(III) levels. The present work evaluates the potential of CPWC for As(III) removal through batch and continuous column studies. The As(III) uptake appears to be rapid in the first 60 min, and achieves equilibrium by 180 min. The pseudo-second-order kinetic model best describes the experimental kinetics data. The Freundlich isotherm represents the equilibrium data. The continuous column studies yield decreased volume of treated water at breakthrough with increase in flow rates, whereas the volume of treated water increases with increase in bed depth. The error between predicted and experimental values of service time varies between 0.28 and 21.85%. The study indicates significant potential of CPWC for As(III) removal.