Sorption potential of impregnated charcoal for removal of heavy metals from phosphoric acid

The viability of some heavy ions removal from phosphoric acid solution by means of impregnated charcoal with triphenylphosphine sulphide extractant has been demonstrated in this work. Factors affecting removal of Cu2+, Cd2+, Zn2+and Pb2+ include initial concentration of ions, volume of the aqueous solution to weight of adsorbent ratio (V/m), concentration of the extractant loaded onto charcoal and temperature. The removal percent of these ions is increased by decreasing values of V/m ratio and increasing temperature for all ions. The sorption isotherms data fit Langmuir, Freundlich and Dubinin-Radushkviech (D-R) models. The values of the mean free energy, Ea, of sorption is in all cases in the range 9.1-25.6 kJ/mol, which are within the ranges of chemical sorption reaction. The sorption reaction was found to obey a pseudo second-order rate model.