Kinetics of the Adsorption for Naphthol Green by Epichlorohydrin Modified Peanut Shell

The adsorption of naphthol green by peanut shell, which was chemically-modified by cross-linking with epichlorohydrin was studied with variation in the parameters of contact time and temperature. They were used for equilibrium adsorption uptake studies with naphthol green. The results revealed that adsorption equilibriums were rapidly established in about 3h. Three different kinetic models (i.e.,intraparticular diffusion model, Lagergren-first-order and second-order equations) were used to describe the adsorption kinetic mechanisms. The adsorption of naphthol green on epichlorohydrin modified peanut shell(EMPS) was not controlled by intraparticular diffusion. The kinetic adsorption data can be well simulated by the second-order equation and the adsorption might be rate-limiting controlled. The suitability of the adsorbent was evaluated by fitting the equilibrium data with Langmuir and Freundlich isotherms, which gave good fits with both isotherms.