Environmental optimization of continuous flow ozonation for urban wastewater reclamation

► We studied the ozonation of wastewaters spiked with 12 emerging pollutants. ► We used a continuous bubble-column ozonation system. ► The environmental impacts of ozonation were assessed using Life Cycle Assessment. ► Pollutant removal beyond certain limit sharply decreases ozone usage efficiency. ► Maximizing toxicity removal led to higher greenhouse-gas emissions.