The kinetics of oxidation and disinfection processes during ozonation in a full-scale reactor treating secondary wastewater effluent were investigated for seven ozone doses ranging from 0.21 to 1.24 g O-3 g(-1) dissolved organic carbon (DOG). Substances reacting fast with ozone, such as diclofenac or carbamazepine (k(P,O3) > 10(4) M-1 s(-1)), were eliminated within the gas bubble column, except for the lowest ozone dose of 0.21 g O-3 g(-1) DOG. For this low dose, this could be attributed to short-circuiting within the reactor. Substances with lower ozone reactivity (k(p,O3) < 10(4) M-1 s(-1)) were only fully eliminated for higher ozone doses.