Polymerization Effects of Ozone: Applications to the Removal of Phenolic Compounds from Industrial Wastewaters

Abstract

Degradation of phenols by ozone has been extensively studied but the oxidative coupling pathway of ozone resulting in a phenol polymerization has not been largely investigated. Application of low ozone dose in solutions of 2.4 dichlorophenol and salicylic acid is characterized by the formation of high molecular compounds which are partially insoluble. Numerous polymers have been identified by gas chromatography coupled with mass spectrometry. Application of the polymerization effect of ozone to petrochemical and coking wastewaters containing phenols give similar results. In each case, phenolic compounds are efficiently removed, even if a large organic content is present. In the case of petrochemical wastewater, where phenols represent only 30% of TOC, the ozone effects are not sufficient to merit an ozonation step on the present treatment line. On the other hand, when phenols represent the greater part of the organics, as in coking wastewater, an important fraction of insoluble compounds, easily removed by filtration, are formed.