A Box-Behnken design-based chemometric approach to optimize the removal of phosphate ions from water using Punica granatum shells

The present study was aimed at evaluating the adsorption of phosphate ions using Punica granatum shells (PGS) as an environmentally friendly and economical sorbent material. The PGS powder was characterized by several techniques including BET, pHpzc, SEM, and FTIR, as well as its adsorption capacity evaluated with the sorption of PO43- from water. To achieve adequate removal of PO43- from water, a chemometric method based on the Box-Behnken design was applied to optimize the influence of the main operating factors such as the PGS amount (0.10-1 g L-1), medium pH (3-9), and PO43- initial concentration (10-100 mg L-1) on the adsorption processes. Noteworthy, the best adsorption amount (29.31 mg g(-1)) was obtained at a pollutant dose of 72.72 mg L-1, an adsorbent quantity of 1 g L-1 in medium acid pH 3 at 25 degrees C. The modeling study suggests that the process of PO43- uptake follows the pseudo-second-order model with a maximum adsorbent quantity of 32.25 mg g(-1). [GRAPHICS]

Automated summary

The aim of this study was to evaluate the adsorption of phosphate ions using Punica granatum shells as a sorbent material. The PGS powder was characterized and its adsorption capacity for PO43- was evaluated. A chemometric method based on the Box-Behnken design was applied to optimize the operating factors. The best adsorption amount was obtained at specific conditions and the process followed the pseudo-second-order model with a maximum adsorbent quantity.