Assessment of a hollow cylindrical Ti–TiO2/IrO2/RuO2 mesh electrode for effective treatment of hospital wastewater using a portable electrochemical reactor

Hospital wastewater (HWW) comprises a complex matrix of organic and inorganic contaminants, pathogenic microorganisms, and heavy metals that pose significant environmental and public health concerns. This study investigates the performance of a compact and field-deployable electrochemical oxidation (EO) reactor comprising a Ti–TiO2/IrO2/RuO2 hollow cylinder anode in raw HWW was investigated in this work. A careful analysis of the physicochemical parameters of HWW showed high concentrations of total dissolved solids (4,567 mg L−1), total suspended solids (2,836 mg L−1), COD (3,108 mg L−1), and BOD (1,230 mg L−1), The EO process was performed at current densities 5.8, 10.4 and 15.5 mA/cm2 and maximum COD removal (92 %) at 15.5 mA/cm2 after 10h of treatment. The compact anode possessed a crack-propagated surface morphology that is beneficial for Cl2 evolution reaction, and flower-like scale deposits with mainly Ca and Mg phases revealed by XRD were observed on the cathode, and verified by HR-SEM and EDX. The EO process effectively eliminated both fecal and total coliforms within 60 min and significantly decreased the levels of heavy metals (Fe: 945 → 450, Cu: 732 → 345, Zn: 650 → 140, Mn: 68 → 15 and Pb: 20 → 5.0 ppm). FT-IR and GC-MS studies showed significant degradation of organic compounds, which resulted in the reduction of toxic substances and the production of less harmful products. The treatment is enhanced by in-situ generated active chlorine species (Cl2, HOCl and OCl-), that oxidize and mineralize organic-matter. These findings confirm that the EO process has the potential for effective treatment of HWW, resulting in environmental-safe reuse of treated HWW for irrigation use and reduced the environmental footprint of hospitals.