Adsorption kinetics and modeling of Cu(II) ion sorption from aqueous solution by mercaptoacetic acid modified cassava (Manihot sculenta cranz) wastes

The rate of removal of Cu(II) ions from aqueous solution by mercaptoacetic acid modified cassava wastes (0.5MCF and 1.0MCF) was studied in batch conditions. The rate of sorption of copper was rapid initially within 5-15 minutes and reached a maximum in 30 minutes. Kinetic modeling analysis of the Elovich, pseudo-first order, pseudo-second order, intraparticle diffusion, mass transfer and intraparticle diffusivity equations using the linear coefficient of determination r2 values showed that the pseudo-second order equation was the most appropriate model for the description of Cu(II) transport. Thus the sorption of Cu(II) ion can be said to follow a pseudo-second order model, with chemical sorption as its rate limiting step. The initial adsorption rate values were: 2.94 x 10-1 and 2.60 x 10-1 mg.g-1.min-1 for 0.5MCF and 1.0MCF adsorbents respectively.