Lead (II) and nickel (II) adsorption kinetics from aqueous metal solutions using chemically modified and unmodified agricultural adsorbents

This paper discusses the kinetics of lead (II) and Nickel (II) ions adsorption from aqueous solutions using chemically modified and unmodified agricultural adsorbents at 28°C, pH 6.2 and 0.01M NaCl ionic strength. The removal of the two metals were found to increase with increase in chemical modification, the sequence being 1.0MOPF>0.5MOPF>UOPF. In addition Nickel (II) had a higher percentage removal than lead (II). The intraparticle diffusion rate constant (Kid) were determined to be 63.023 min-1 (Ni2+) and 38.212 min-1 (Pb2+) for the 1.0MOPF adsorbent. The results show that the intraparticle diffusion model fits the sorption of lead (II) with higher coefficient of determination (r2) than Nickel (II), thereby indicating that the intra-particle diffusion may be the rate limiting step for Pb2+ sorption. The results from this study indicates that a good adsorbent for the removal of Ni2+ and Pb2+ can be obtained from both chemically modified and unmodified oil palm fruit fibre