Figure 3

Effect of HRT on COD reduction during catalytic ozonation under continuous mode. Experimental conditions: (a) without addition of PAM; ozone dosage = 12.2 g-O3/min (ozone concentration = 120 mg/L; ozone flow rate = 6.08 m3/h); (b) with addition of 2 mg/L PAM; ozone dosage = 10.2 g-O3/min (ozone concentration = 120 mg/L; ozone flow rate = 5.11 m3/h).