Study of the advanced oxidation processes of chlorobenzenes in water

The focus of this study was to investigate the use of advanced oxidation processes to oxidize a residual water in which chlorobenzenes were found in the range of 1 mg/L to 10 mg/L and whose TOC was about 1,000 mg/L, and a solution of chlorobenzenes whose concentration was 0.03 mg/L, which was prepared from stock solutions. Ozone in basic medium (pH = 9) and ozone in the presence of hydrogen peroxide (H2O2) were compared. The carbonyl ozonation byproducts (Glaze, 1989) have been identified as PFBOA [O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine] derivatives by gas chromatography/mass spectrometry (GC/MS). A quantitative analysis by GC/ECD (gas chromatograph equipped with an Electron Capture Detector) and by GC/FID (Flame Ionization Detector) was carried out on the complete series of chlorobenzenes in order to determine the elimination levels reached after treatment with ozone and ozone/hydrogen peroxide. 2-Chlorophenol and 4-chlorophenol were identified as first oxidation byproducts of chlorobenzene.