ADSORPTION THERMODYNAMICS OF CO(II) ON POLYSULFIDE TREATED SAWDUST

Sawdust of rubber wood has been subjected to surface modification by t reatment with sodium polysulphide. The product exhibits a good adsorpt ion potential for Co(II). The percentage of Co(II) adsorption increase s with increase in temperature and decrease in initial Co(II) concentr ation. Sorbent is effective for the quantitative removal of Co(II) ove r the pH range 4-10. The applicability of the Lagergren and Freundlich equations for metal removal has been tested at different temperatures and the adsorption has been found to be endothermic. Thermodynamic pa rameters have also been calculated to predict the nature of adsorption . The spent sorbent can be regenerated by acid and can be reused.