Comparative study of adsorptive removal of oxyanion (Cr2O4 -2) from aqueous media over unmodified and magnetically modified Melia azedarach

In the present study, unmodified Melia azedarach (UMA) and magnetically modified Melia azedarach (MMA) were used as a low cost biosorbent for the adsorptive removal of oxyanion (chromate ion Cr2O42-) from aqueous solution. The UMA and MMA were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning electron microscopy (SEM). Batch biosorption process was used to check the effect of well-known process parameters including biosorbent dose, contact time and pH of solution. Experimental results revealed that MMA has more adsorption capacity as compared to UMA. Maximum % age removal (60.49%) was observed under acidic condition (pH=2) using MMA. The obtained experimental data was evaluated using Langmuir and Freundlich isotherms as well as pseudo 1st and 2nd order reaction kinetic models. Results showed that equilibrium mechanism can satisfactorily be explained by Langmuir model as depicted by the correlation factor (close to unity) and follows 2nd order reaction kinetic models.