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 degrees 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 degrees C) exhibited lower surface area (0.25 m(2)/g), and high K (1.94%) and FIX (0.905) content. The maximum cymoxanil adsorption capacity of 161 mg CM/g BC at pH 7 was achieved in biochar produced at 350 degrees 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. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study evaluated the adsorptive behaviors of grape pomace-derived biochar for the removal of the pesticide cymoxanil. Biochar produced at low pyrolytic temperature showed the highest cymoxanil adsorption capacity at pH 7, attributed to a combination of metal and hydrophilic interactions. The pseudo-second order kinetics and Freundlich isotherm model were found to be the best fit for the adsorption process.