Biochar Generated from Agro-Industry Sugarcane Residue by Low Temperature Pyrolysis Utilized As an Adsorption Agent for the Removal of Thiamethoxam Pesticide in Wastewater

Biochar produced from different raw materials by pyrolysis have been utilized as an alternative material for organic compound adsorption. This study aims to evaluate the use of biochar generated from sugar cane filter cake, after pyrolysis treatment at 380 °C, in the adsorption process of thiamethoxam pesticide in wastewater. The biochar was studied based on moisture, volatile matter, ash content, surface area and porosity, using elemental analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy. The results showed that the use of biochar as an adsorbent for organic compounds is promising, due to its surface area (19.8 m2 g−1), mesoporosity, and functional groups, such as hydroxyl, present on the biochar surface. The Langmuir and Freundlich isothermal models were used for the adsorption study. The pseudo-first- and pseudo-second-order models were used in the kinetic study of the adsorption process. The results indicated that the adsorption process was well described by the Langmuir isotherm and pseudo-second-order models. Finally, the rate of thiamethoxam removal by biochar was approximately 70% over a period of 60 min, and biochar is, therefore, suitable for the decontamination of wastewater with thiamethoxam.