Biochar-Based Nanocomposites as Catalysts for Photo-assisted Electrochemical Technologies: Sustainable Solutions for Contaminant Emerging Concern Degradation.

This project focuses on the development of innovative biochar-based nanocomposites as catalysts for light-assisted electrochemical technologies. Biochar materials derived from abundant native Chilean biomass (Chilean hazelnut shell and cherry pit) will be produced in heterojunction designs to reduce the production costs of the treatment system, making it a more economically viable option for large-scale treatment. Sustainable biochar-based composites such as ZnO@ZnFeO4@HSBC, ZnO@ZnFeO4@CPBC, ZnO@MgFeO4@HSBC, and ZnO@MgFeO4@CPBC will be synthesized, which will be used as photoactive catalysts in the hybrid adsorption/photocatalysis/(solar) photoelectro-Fenton process for the removal of various CECs in different water matrices.

The project will be carried out through four interconnected work packages (WPs), each running simultaneously:

• WP1: Will focus on the synthesis and characterization of biochar-based nanocomposites using various techniques.

• WP2: Will concentrate on the degradation of a model CEC mixture and on bacterial inactivation tests in synthetic water and real municipal wastewater effluents, using the nanomaterials from WP1.

• WP3: Will identify the main active species and intermediates generated during the WP2 treatments.

• WP4: Will evaluate the feasibility of the developed hybrid technologies through scale-up and techno-economic assessment.

Laboratory-scale degradation experiments will be carried out in a 150 mL undivided, truncated-cone-shaped glass cell open to the atmosphere. The experimental synthesis and treatment parameters will be optimized by varying key operational conditions such as catalyst concentration, initial pH, current density, and water matrix. The scale-up to a 10 L capacity pre-pilot plant and the techno-economic assessment will address the crucial step toward the future implementation of adsorption/photocatalysis/(solar) photoelectro-Fenton technologies using biochar-based nanomaterials in industrial or public facilities.

In the present project, the integration of adsorption, photocatalysis, and (solar) light-assisted Fenton-based electrochemical processes using biochar catalysts is expected to significantly improve the efficiency and effectiveness of wastewater treatment, achieving higher contaminant removal rates and reduced treatment times. Furthermore, the use of sustainable biochar materials derived from abundant native Chilean biomass in heterojunction designs would reduce production costs, making it a more economically viable option. In addition, they would overcome the current technical limitations of electrochemical technologies, showing good prospects for industrial applications.