ADSORPTION OF PHOSPHATE ONTO PUMICE POWDER

The adsorption of phosphate onto pumice powder was studied as a functi on of time, pH and total dissolved phosphate concentration. Phosphate removal efficiency was found to be more than 80%. The adsorption react ion was considered to be a reversible reaction at which a forward firs t order reaction is opposed by a second order reaction. The reaction r ate constant k was calculated as 28.31 +/- 2.37 x 10(-3). Phosphate ad sorption data had a good fit to Freundlich adsorption isotherm at pH 3 , 5, 7 and 9. In the presence of NaCl, Na2SO4, MgCl2, CaCl2, NaF and u rea, the adsorption was slightly affected.