Biosorption, Isotherm and Kinetic Studies of Methylene Blue Dye Removal from Aqueous Solution using Citrus Peels as Adsorbent
Authors: Sanusi I, Gutti B, Giwa SO
Waste water generated by many industries such as textiles and cosmetics industries contain organic dye stuff that is harmful to humans and aquatic organisms. As a result, this study was conducted on the biosorption of methylene blue using various bio-waste materials namely, sweet orange peels (OP), grape fruit peels (GP) and lime peels (LP) and their combinations (OP + GP and OP + LP) as biosorbents for the removal of methylene blue dye from solution. The peel samples were dried, pulverized and characterized for functional groups and surface morphology using Fourier transform infra-red (FTIR) spectroscopy and scanning electron microscopy (SEM) respectively. Batch experiments were performed to investigate the effect of factors such as contact time, initial dye concentration and adsorbent dosage on methylene blue adsorption. Experimental data were analyzed using Langmuir and Freundlich isotherm models. The data was found to be best described by Langmuir adsorption isotherm (R2 = 0.998) with maximum adsorption capacity of 29.533mg/g for monolayer coverage. Optimum methylene blue removal efficiencies at 0.6g/20ml dosage was found to be 82, 85 and 84% respectively for OP, OP+GP and OP+LP, whereas at 0.8g/20ml dosage, 68 and 61% efficiencies were recorded for GP and LP respectively. Maximum removal efficiency of 85% for OP+GP was achieved at 150 minutes contact time. Several biosorption kinetic models were tested and the results showed that citrus peel biosorbent followed the pseudo-second-order kinetics.
Affiliations: Department of Chemical Engineering, Abubakar Tafawa Balewa University, Bauchi, PMB 0248, Bauchi, Bauchi State, Nigeria
Keywords: Biosorption, Adsorbent, Methylene Blue, Aqueous Solution, Kinetic Models
Published date: 2018/12/30