ABSTRACT

The adsorption of Pb (II) ion onto mixed Achatina fuscatus(P) and Tympanotons fuscatus(S) powder was studied. The results showed that the rate of adsorption increases with increase in initial concentration with time from ten minutes and attained equilibrium at ninety minutes for all combination mixtures of P:S: 100/0, 80/20, 50/50, 20/80, 0/100. An exceptional increase in adsorption was observed for the combination of P:S 20/80, which implies that the presence of a little quantity of snail shell powder increases the efficiency of adsorption of the periwinkle shell. The equilibrium data was subjected to Langmuir, Freundlich and Flory-Huggin model. The data best fitted Langmuir, this is evident in its high correlation coefficient values of 0.9911, 0.9960, 0.9971, 0.9986 and 0.9998 for P:S: 100/0, 80/20, 50/50, 20/80 and 0/100 respectively.