Kinetics and thermodynamics of phenanthrene adsorption from water on orange rind activated carbon

The present study investigates the kinetics and thermodynamic behaviour of a typical polycyclic aromatic hydrocarbon, phenanthrene, for the adsorption onto activated carbon developed by orange rind. Polycyclic aromatic hydrocarbon (PAHs) is an ubiquitous and hazardous category of environmental pollutants. Various industrial as well as household activities play a major role in their deposition in the aquatic bodies. To investigate the kinetics of phenanthrene adsorption on prepared activated carbon, the models of Lagergren and Ho-McKay were applied. The results suggest the better applicability of pseudo-first order (Lagergren) model than pseudo-second order (Ho-McKay) model. Langmuir adsorption isotherm was used for evaluation of thermodynamic parameters. The mechanism of adsorption of PAH was found to be intra-particle diffusion. The negative values of thermodynamic parameter, ΔG∘, reveal spontaneity of the adsorption process. The activated carbon derived through rind of orange was found suitable to adsorb phenanthrene from aqueous mediums. The study is useful to explain the feasibility of the adsorption process.