Optimizing copper ions removal from industrial leachate by explored vermiculite-A comparative analysis

In this work, the sorbent behavior of vermiculite to remove copper from industrial leachate was studied in batch experimental system. The effect of initial pH (3, 6, and 8), adsorbent dosage (2, 6, and 10 g/L), and contact time (5, 20, and 60 min) on the removal of heavy metals was investigated. At first stage, one-factor-at-a-time experiments were performed to see the individual effects of initial pH, adsorbent dosage, and contact time. The statistical solutions are implemented to decide which one of them is most suitable for adsorption studies. To study the two factor interactions, response surface modeling (RSM) based on Box-Behnken (BB) approach, factorial D-optimal design and Taguchi methods are. The adsorption kinetic models were also tested for the validity. The second order model with the high correlation coefficients best described adsorption kinetic data. Lagergreen first order, Elovich, and the pseudo-second order kinetic model are employed to optimized levels of the analyzed factors. Finally, the removal of Cu(II) using vermiculite reached at 96.87%, at the optimum level of 8 initial pH, 10 g/L of adsorbent dosage, and 10 min of contact time. Taguchi design was found to be appropriate on account of time-consuming and cost-effectiveness.