Eco-friendly synthesis of a novel adsorbent from sugar cane and high-pressure boiler water.

The development of industrial process in line with the circular economy and the environmental, social and corporate governance (ESG) is the foundation for a sustainable economic development. Alternatives that make feasible the transformation of residues in added value products are promising and contributes to the repositioning of the industry towards sustainability, due to financial leverage obtained from lesser operational costs when compared with conventional processes, therefore increasing the company competitivity. In this study is presented a promising and innovative technology for the recycling of agro-industrial residues, the sugarcane bagasse and the high-pressure water boiler effluent, in the development of a low-cost adsorbent (HC-T) using the hydrothermal carbonization process and its application in the adsorption of herbicide Diuron and Methylene Blue dye from synthetic contaminated water. The hydrothermal carbonization was performed in a Teflon contained inside a sealed stainless-steel reactor self-pressurized at 200 °C, biomass-to-effluent (m/v) ratio of 1:3 and 24 h. The synthesized material (HC) was activated in an oven at 450 °C for 10 min, thus being named adsorbent (HC-T) and characterized by textural, structural and spectroscopic analysis. The low-cost adsorbent HC-T presented an 11-times fold increase in surface area and ∼40% increase total pore volume in comparison with the HC material. The kinetic and isotherm adsorption experiments results highlighted that the HC-T was effective as a low-cost adsorbent for the removal of herbicide Diuron and Methylene Blue dye from synthetic contaminated waters, with an adsorption capacity of 35.07 (63.25% removal) and 307.09 mg g-1 (36,47% removal), respectively.