Removal of vanadium from wastewater using surface-modified lignocellulosic material.

Palm fruit husk, a lignocellulosic material, is an agricultural solid waste. Since raw palm fruit husk does not adsorb V (V), it was subjected to surface modification with a cationic surfactant cetyl trimethyl ammonium bromide (CTAB). The surface-modified palm fruit husk showed adsorption capability for V (V). The maximum adsorption of V (V) takes place at pH 4. Adsorption equilibrium data were fitted to Langmuir, Freundlich, and Dubinin Radushkevich (D-R) isotherm models. Kinetic studies showed that the adsorption data fit second-order kinetic model better than first order. Desorption of V (V) proved that it is feasible to recover V (V) from the spent adsorbent. Effect of coexisting anions like Molybdate, sulfate, nitrate, phosphate, and thiocyanate on the adsorption of V (V) was also studied and the foreign ions compete for the adsorption sites with V (V) anionic species. Quantitative removal of V (V) was achieved from synthetic wastewater.