Abstract
The present study deals with the successful utilization of bacterial biosorbent Arthrobacter sp. for the removal of Cd(II) ion from water in a batch and a continuous system. The maximum uptake capacity of free and immobilized biomass in batch system was 270.27 and 188.67 mg/g, respectively. The maximum removal percentage Cd2+ of 88.9% was obtained at flow rate of 1.0 mL/min and 19 cm bed height in the column system. The bed depth service time (BDST) model was applied, which was found to be in good agreement with the experimental data with high correlation coefficient (>0.997) and low chi-square value (> 1.62). Thomas and Yoon-Nelson models were also applied to the experimental data, and the Yoon-Nelson model provided a better description of experimental kinetic data in comparison to the Thomas model. Column regeneration studies were also carried out using 0.1 mol/L HCl as desorbent. for seven sorption-desorption cycles. Furthermore, an attempt has been made to optimize the process conditions for the maximum removal using the central composite design, and the result predicted by optimization plots was 89.64%, which is close to the experimental data, that is, 88.9% at the same process conditions.