Continuous column study of Cu(II) and Pb(II) ions on alkali-treated coir

Biosorption of Cu(II) and Pb(II) ions by alkali-treated coconut coir (ACC) in a continuous fixed-bed column was carried out from their aqueous solutions. ACC was characterized by FTIR and SEM. The effect of process parameters like bed height, flow rate, and influent initial metal ion concentration was examined. The exhaustion time increased with increase in the bed height and decrease in the flow rate and influent initial concentration. Bohart-Adams, Thomas, and Yoon-Nelson models were found useful for estimating the model parameters of the fixed-bed column, which are valuable for process design as well as to describe the adsorption under changing experimental conditions for predicting the breakthrough curves. Thomas model was the best to fit the breakthrough curves at experimental conditions. The biosorbent was regenerated using 0.01 N NaOH at an eluent flow rate of 10 mL/min and reused up to three times repeatedly without considerable loss in sorption capacity, demonstrating its suitability for commercial application. Sorption of these metal ions from synthetic wastewater has shown excellent potential of ACC for bulk-scale operations.