Carbon prepared from the wood of Paulownia tomentosa (PT) was treated 1with mixture of acids (HCI and HNO3), KOH and n-hexane and activated at 400 and 800 oC. Activation removed the surface oxygen functional groups (carboxyl’s, lactones or phenols and ethers) and exposed the pores. Increase in the amount of carbon with respect to oxygen resulted which enhanced the dye adsorption. First order and Bangham kinetic equations were found to apply to the data, indicating the adsorption to be diffusion controlled. Rate constant increased with the increase in both the adscription temperature and the activation temperature of carbon. Thermodynamic parameters of adsorption (Ea, DH, DS and DG) were calculated. The endothermic nature adsorption was indicated by the positive values of 4H’. Negative values of DS found for adsorption, reflect decrease in the disorder of the system at the solid-solution interface during adsorption. Gibbs free energy (DG¹), that represent the driving force’ for the affinity of dye for the carbon, increased with the decrease in adsorption temperature but increased with activation temperature of the carbon.
S ALAM ,F K BANGASH ,
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