Adsorption of Atrazine by Biochars Produced From Byproducts of the Wood Industry

Abstract

Atrazine is a herbicide widely used in agriculture; however, because of its toxicity, alternatives are needed to remove this compound from the environment. In this study, we investigated the adsorption process and the atrazine-adsorbing ability of three biochars produced at different pyrolysis temperatures from byproducts of the wood industry. The biochars were characterized by Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), and their physical characteristics were evaluated by Brunauer-Emmett-Teller (BET) analysis. The biochar pyrolyzed at 350 °C (BM350) adsorbed 26.04% of the herbicide, showing the best performance among the three biochars tested, even though it had the lowest specific surface area (1.467 m 2 g-1). It also had a greater quantity of organic functional groups, which may have influenced the adsorption. The kinetics of the adsorption process were best explained by the pseudofirst-order model and by the Freundlich isotherm model. However, the biochar is not suitable for the removal of the herbicide atrazine, having a lower adsorption capacity than those of others described in the literature.