A techno-economic assessment of the potential for combining supercritical water oxidation with ‘in-situ’ hydrothermal synthesis of nanocatalysts using a counter current mixing reactor

•A combined oxidation/synthesis process for contaminant removal.•Lower temperature requirements for contaminant removal compared to other papers.•A comparison of the effectiveness of different nanocatalysts in contaminant removal.•Experiments to show how oxidant addition impacts on contaminant removal efficiency.•An initial techno-economic assessment showing benefits of the process vs current standards.