Coagulation-flocculation followed by catalytic ozonation processes for enhanced primary treatment during wet weather conditions

Combined sewer overflows (CSO), generated during the wet weather flow from combination of inflow and stormwater runoff in system, result an overflow untreated wastewater which might ultimately contain different micropollutants (MPs). In this study, a coagulation-flocculation-sedimentation (CFS) pretreated CSO spiked with MPs was treated by catalytic ozonation using carbon, iron, peroxide-based catalysts. The catalysts were characterized their activity on removal studied at two ozone (O3) doses (5 10 mg L?1). effect treatment effluent also assessed acute toxicity Microtox®, Yeast, Macrophage cell-line assay tests. All carbon-based showed large surface area, strongly influenced activation technique preparation CFS reduced turbidity (?60%) but had marginal UV254, dissolved organic carbon (DOC), pH. Sludge Based Carbon (SBC) strong adsorption capacity (?60% efficiency) for all compared to other iron-based Ozonation alone effective degradation easily oxidizable (sulfamethoxazole, mecoprop, 2,4-dichlorophenoxyl acetic acid), achieving more than 80% efficiency L?1 ozone, not atrazine (?60% similar O3 dose. Catalytic (at dose) improved low catalyst dosage higher inhibited degradation. cases, effluents negligible toxicity, indicating suitability process CSO.