Adsorption technique for the treatment of As(V)-rich effluents

Unconventional adsorbents like hematite and feldspar have been employed for the removal of AS(V) from aqueous system. The effect of important parameters like solute concentration, detention time, pH, temperature, agitation rate and particle size of the adsorbent has been addressed. The process of uptake follows first-order kinetics and the data fit the Langmuir isotherm. Mass-transfer coefficients and diffusion coefficients have also been determined to study the dynamics of transport. The pH of the system has been found to play a key role in the uptake. The maximum removal was found to be 100% with hematite and 97% with feldspar under optimum conditions at 13.35 mu mol L(-1) arsenic concentration. The data were subjected to multiple-regression analysis and a model has been developed to predict the uptake capacity of the adsorbents under given boundary conditions.