Kinetics and mechanistic description of adsorptive uptake of crystal violet dye by lignified elephant grass complexed isolate

Lignified isolate was successfully synthesized from simulated effluent of modified procedure for bio - ethanol production from elephant grass. The effectiveness of lignin isolate (EA); complexed with Al3+ (Al - EA) and Mn2+ (Mn - EA) for adsorbing aqueous crystal violet dye (CVD) was evaluated. The adsorbents were characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Removal efficiencies of Al k EA (98.42%) and Mn - EA (97.87%) were obtained at contact time of 30 min and 343 K. Kinetic study showed that Brouer - Weron - Sotolongo, Fractal - like mixed 1,2-order and Elovich models were the best three models in describing the adsorption kinetics of both adsorbent. Similarly, the predicted kinetic data were adjured statistically significant using F-test and student's t-test. Application of mechanistic models suggests film diffusion as the rate controlling mechanism. The estimated average thermodynamic parameters (Delta G(0) (-18.438 KJ/mol),Delta H-0 (+ 27.968 KJ/mol) and Delta S-0 (29.536 KJ/mol)) reveal that CVD adsorption onto Al - EA and Mn - EA was feasible, spontaneous and endothermic.