Modeling the mass transfer in biosorption of Cr (VI) y Ni (II) by natural sugarcane bagasse

Abstract

The Cr (VI) and Ni (II) ion biosorption process by natural sugarcane bagasse in a fixed bed column was investigated. The characteristic removal parameters such as retention capacity, removal percent and unused bed length were experimentally determined at different operating conditions. Overall mass transfer coefficient was investigated and reported for the studied biosorption system. The breakthrough curves were simulated using Matlab2010a software to check the validity of the obtained overall mass transfer coefficients. Experimental data fitted well with predicted data (R2 = 0.94). A statistical analysis was performed using the software Statgraphics Centurion-X V15.2.06 to compare the simulated and experimental data. No significant differences were observed between experimental and simulated data. The best operating conditions for Cr (VI) removal were 15 mg/L of inlet concentration and 1.5 g of biosorbent. For Ni (II) removal the best results were obtained with 25 mg/L of inlet concentration and 1.5 g of solid. The results obtained through the breakthrough curve showed high removal percentages (94.70 and 97.90% for chromium and nickel, respectively). Moreover, results indicated that sorption of these metals was irreversible and it was controlled by the mass transfer at the external film.