A novel stirrer for feasible use of 3D-printed carbon-based catalysts within semi-batch systems

Abstract New approaches to enable the application of carbon catalysts in advanced water treatment processes have gained increasing attention. Additive manufacturing, particularly 3D printing, offers a pathway to transform powder catalysts into macrostructured forms. Carbon-based materials have demonstrated significant promise as catalysts for the degradation of organic pollutants through ozonation. This study evaluates the performance of 3D-printed carbon-based catalysts (3DPCCs) in the ozonation of oxalic acid (OxAc), a recalcitrant organic compound. While these catalysts initially exhibited limited mechanical stability under reaction conditions optimised for powder catalysts, adjustments were made to the system to enhance performance. A novel stirrer equipped with a perforated case was designed and operated at 200 rpm in a semi-batch reactor setup. This configuration enabled promise ozonation of OxAc, achieving a 90% removal rate within 180 min, thus confirming the catalytic efficacy of 3DPCCs under optimised conditions.