Polyphenols Content, Chelating Properties and Adsorption Isotherms and Kinetics of Red and Yellow Pomegranate Peels (Punica granatum L.) Towards Lead (II)

Metal pollutants produced by industrial wastewaters have become a global concern given their impact on the environment and human health. The purpose of this study was to assess the polyphenols content and the iron chelating activity in the peels of two pomegranate varieties. After the biomass characterization via FT-IR, point of zero charge and surface functional groups analysis, the lead adsorption was then investigated by batch method. Finally, the regeneration of the biomasses was performed by acidic desorption. Polyphenols content of the red peels extract was higher than the yellow one; 102.9 +/- 0.9 and 85.9 +/- 1.3 mg GAE/g of dry weight, respectively with a half iron chelation inhibitory concentration (IC50) of 227.2?+/- 1.7 and 235.9 +/- 3.2 mu g.mL(-1) of extract, successively. For the adsorption isotherms of lead onto the red and yellow pomegranate peels, the Langmuir model was more fitting with an adsorption capacity (Qmax) of 90 and 89.25 mg.g(-1), respectively. The kinetic data corresponded better to the pseudo-second order model. The acidic desorption of lead was successful with a high percentage of recovery. The results demonstrate the effectiveness of these biomasses as biosorbents for lead removal from aqueous solutions with the possibility of their reuse.