This research was aimed at studying oxidation processes, coliform inactivation effectiveness and disinfection byproducts (DBPs) associated with the disinfection of anaerobic sanitary wastewater effluent with ozone applied at doses of 5.0, 8.0 and 10.0 mg O(3) L(-1) for contact times of 5, 10, 15 min. The wastewater used in this research was generated by the wastewater treatment plant (WWTP), University of Sao Paulo - Brazil. The total coliform inactivation range was 2.00-4.06 log(10), and the inactivation range for Eschericlna coli was 2.41-4.65 log(10) Mean chemical oxygen demand (COD) reductions were 37.6%, 48.8% and 42.4% for doses of 5.0, 8 0 and 10.0 mg O(3) L(-1), respectively. Aldehyde formation varied with dosage only when the ozone dose was increased from 5.0 to 8 0 mg O(3) L(-1) for acetaldehyde and from 5.0 to 8 0 and from 8.0 to 10 0 mg O(3) L(-1) for glyoxal. (C) 2010 Elsevier Ltd All rights reserved.