THE COMBINATION OF PHOTOCATALYSIS AND OZONOLYSIS AS A NEW APPROACH FOR CLEANING 2,4-DICHLOROPHENOXYACETICACID POLLUTED WATER

Treatment of 2,4-D polluted waters with photocatalysis leads to the bu ildup of high concentrations of the long living intermediate 2,4-DCP. A new approach using a combination of ozonolysis and photocatalysis ga ve better degradation results with lower intermediate concentrations. The advantages of photocatalysis giving a constant decline in TOC and of ozonolysis giving no buildup of high intermediate concentrations we re combined. Degradation data of 2,4-D for photocatalysis, ozonolysis and the combination of both for different pH ranges are given. Data on the main intermediate 2,4-DCP are given for the three different appro aches. (C) 1998 Elsevier Science Ltd.