The Cu/Al2O3 catalyzed ozonation for degrading an endocrine disruptor-alachlor in water was investigated. The Cu/Al2O3 powders were coated on a cordierite honeycomb column, which was taken as the reactor of catalytic ozonation of alachlor. Additional uncatalyzed experiments were carried out and the results were compared to those of the catalytic runs. The experimental results demonstrated that Cu/Al2O3 was a very effective catalyst for ozonation of alachlor. The removal rate of alachlor in total organic carbon (TOC) with ozonation in the absence of Cu/Al2O3 was only above 20% in 180 min, while the reduction of totle organic carbon (TOC) in the presence of Cu/Al2O3 was more than 60%. Correspondingly, more inorganic ions created and less by-products produced in the Cu/Al2O3 catalyzed ozonation than in the unanalyzed process. These results indicated that the use of Cu/Al2O3 substantially enhanced the mineralization of alachlor in ozonation. The EPR experiments verified that more (OH)-O-. radicals generated in the Cu/Al2O3 catalyzed ozonation could bring on a higher alachlor removal rate. (C) 2004 Elsevier B.V. All rights reserved.