Grape pomace hydrochar as an efficient adsorbent for cadmium removal

Abstract

Hydrochar prepared from the hydrothermal carbonization of the grape pomace was investigated as potential adsorbent for the Cd from aqueous solution. To increase the sorption efficiency, the hydrochar was modified using the different chemical treatments (citric acid (CA), H2O, and KOH) and characterized by a FTIR spectroscopy. The preliminary adsorption tests showed that the adsorption capacity of hydrochars was 3.8 before and 5.0, 14.5 and 49.34 mg/g upon modification by CA, HO and KOH, respectively. It was observed that the KOH activation enhances the surface functionality of the hydrochar, and thus significantly improves the Cd adsorption capacity. Therefore, the KOH-modified hydrochar should be considered as an efficient adsorbent for Cd removal.