Adsorption behavior of lead ions on pyrophyllite surface

The alumino-silicate based adsorbent pyrophyllite mineral was studied for i ts possible application as an adsorbent for the removal of aqueous lead usi ng the adsorption technique. The effects of different types of pyrophyllite , initial concentration of thelead ion, contact time, temperature and solut ion pH on the adsorption of lead ions were studied by equilibrating, batchw ise, different amounts of pyrophyllite with aqueous solutions of different concentrations. It has been fc,found that pyrophyllite is effective in remo ving 74 to 99% of lead ions from aqueous solutions. The initial rate of ads orption of lead increases with time up to 30 min and thereafter it reaches equilibrium. The rate of adsorption was inversely affected by an increase i n initial concentration of lead. The Langmuir adsorption isotherms were use d to represent experimental data. The adsorption process follows first orde r kinetics and is found to be endothermic.