Assessment of adsorptive behaviors and properties of grape pomace-derived biochar as adsorbent for removal of cymoxanil pesticide

In this work, the adsorptive behaviors and mechanisms of grape pomace-derived biochar (GP-BC) were assessed for the removal of the pesticide cymoxanil (CM). The biochars were produced via pyrolysis carbonization at different temperatures (350, 550, and 750 °C) and batch adsorption experiments were conducted to determine various parameters, such as pyrolytic temperature, initial solution pH, and kinetic and isotherm models. The biochar produced at low pyrolytic temperature (i.e., 350 °C) exhibited lower surface area (0.25 m2/g), and high K (1.94%) and H/C (0.905) content. The maximum cymoxanil adsorption capacity of 161 mg CM/g BC at pH 7 was achieved in biochar produced at 350 °C. Consequently, cymoxanil adsorption was attributed to the combined influences of metal and hydrophilic interaction. In addition, pseudo-second order kinetics and the Freundlich isotherm model were the best fit for cymoxanil adsorption, indicating chemical sorption and multilayer formation on the heterogeneous surface of biochar as adsorptive mechanisms. Our findings imply that GP-BC is a promising adsorbent for pesticide treatment and such an application creates an excellent closed-loop system. [Display omitted] •Grape pomace as residues from wine production was applied for biochar production.•Pyrolytic temperature influenced adsorption capacity and properties of biochars.•Lowest pyrolytic temperature led to effective removal of cymoxanil (CM).•GP-BC350 had the highest CM adsorption capacity (161 mg CM/g BC).•Pseudo-second order and Freundlich models were the best fit for CM sorption.