Sorption Dynamics and Process Development for Removal of Copper from Aqueous Solution using a biosorbent based on Mango tree leaves

摘要

A biosorbent developed from waste leaves of Mango trees (magnifera indica) has been used for the removal of Cu(Ⅱ) from aqueous solution. The use of the biosorbent, Mango lea powder (MLP) was evaluated with respect to the effects of pH, Cu(Ⅱ) concentration, contact time, and biosorbent loading. The sorption dynamics were including kinetics and isotherm fitting, and mechanistic considerations of the processes were discussed in combination with the thermodynamic parameters. Column operations were carried to simulate industrial conditions and parameters like breakthrough volumes were found applying standard procedures. The bed-depth-service-time (BDST) model was applied successfully to the sorptive removal of Cu(Ⅱ). The biosorptive capacity for Cu(Ⅱ) at 90% breakthrough on MLP column decreased from a maximum value of 100 mg g-1 for feed flow rate of 2.0 mL min-1 to 45.00 mg g-1 for 11.2 mL min-1. Reduction in the residence time of the solute at a higher flow rate is likely to create a non-equilibrium situation with Cu(Ⅱ) ions not having enough time to interact with the biosorbent in the column and thus, resulting in a decrease of the amount biosorbed. A slower flow rate also increases biosorption when intra-particle mass transfer controls the sorption process. A lower flow rate or longer contact time is required for effective biosorption of Cu(Ⅱ) ions and an optimal flow rate of 2.0 mL/min could be selected for column design.