Collect. Czech. Chem. Commun. 1987, 52, 960-969

Radiotracer technique in adsorption study, part II. Adsorption of phosphate ions on chromium metal powder

Shuddhodan P. Mishra and Tej Bahadur Singh

Nuclear and Radiochemistry Laboratory, Department of Chemistry, Banaras Hindu University, Varanasi-221005, India


The adsorption of phosphate ions on chromium metal powder from aqueous solutions of sodium dihydrogen phosphate labelled with 32P has been studied as a function of concentrative (10-3 to 10-6 mol l-1), temperature (303-323 K), and pH (3.5-10.6) of the adsorptive solution. The time for the equilibrium establishment was found to be about 4 hours and it is dependent on the solution acidity. The smooth and continuous growth of phosphate adsorption follows the first order kinetics and the rate constants are found to be of the order of 10-3 min-1. The results show that the adsorption in the system under study obeys the Freundlich isotherm. The increase in temperature from 303 K to 323 K does not effect the process markedly. The adsorption kinetics of phosphate ions is highly dependent on pH of the adsorptive solution. On the basis of the present data the nature and mechanism of the adsorption are discussed.