Adsorption potential of maize cob carbon for 2,4-dichlorophenol removal from aqueous solutions: Equilibrium,kinetics and thermodynamics modeling

摘要

The present study deals with the adsorption potential of thermally activated carbon developed from maize cob for the removal of 2,4-dichlorophenol(2,4-DCP)from aqueous solutions.Studies were conducted to delineate the effects of contact time,2,4-DCP initial concentration,pH and temperature.The kinetics of 4-DCP adsorption from a solution onto an adsorbent was explored experimentally.Non-linear form of pseudo-second-order model showed a better fit with good correlation co-efficient.Bangham's and intra-particle diffusion model were also used.Non-linear form of Langmuir isotherm model was applied and the data correlate well and the maximum adsorption capacity was found to be 17.94 mg/g for the particle size of 250-500 mu m.Acidic pH was favorable for the adsorption of 2,4-DCP.Studies on pH effect and desorption showed that chemisorption mechanism was involved in the adsorption process.Thermodynamic study showed that adsorption of 2,4-DCP on maize cob carbon is more favored.The change in entropy(DELTA S°)and heat of adsorption(DELTA H°)of maize cob carbon were estimated as 26.91 J/(Kmol)and 6.78 kJ/mol,respectively.