Hydrothermal carbonization synthesis of cassava slag biochar with excellent adsorption performance for Rhodamine B

In the study, cassava slag biochar was produced from agricultural waste cassava slag by simple hydrothermal carbonization treatment, and its adsorption on dyes in aqueous solution was studied. The structural properties, adsorption performance and mechanism were comprehensively investigated with multiple tools, such as Scanning electron microscopy, Leica microscope, Brunauer-Emmett-Teller, batch adsorption experiments, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The experimental results revealed that the cassava slag biochar could remove 96% of Rhodamine B from aqueous solution, the maximum adsorption amount was 105.3 mg g(-1), and had excellent adsorption regeneration performance as well. The excellent adsorption performance for Rhodamine B could be attributed to intermolecular hydrogen bond and electrostatic interaction. In addition, the cassava slag biochar showed good adsorption performance for different dyes and was economically viable in engineering applications, indicating that it had great potential in practical applications. This study provides a "win-win" solution to improve waste management, reduce environmental pollution by converting the cassava slag into a biochar adsorbent. (C) 2019 Elsevier Ltd. All rights reserved.