Abstract
The photocatalytic degradation of four chlorinated aromatic compounds, namely pentachlorophenol (PCP), 2,4,-dichlorophenol (2,4,-DCP), 3,5,-dichlorophenol (3,5,-DCP), and 2,3,5,-trichlorophenol (2,3,5,-TCP), was investigated in the presence of an aqueous suspension of TiO 2 irradiated with near-UV light. The toxicity of the transient species was compared to that observed for the parent compound. The comparison was carried out by monitoring the inhibition in bacterial respiration ( Escherichia coli) by measuring the CO 2 in the aqueous culture medium using flow injection analysis (FIA). Only in the case of PCP and 2,3,5,-TCP were the intermediates, identified by HPLC and GC/MS, found to be more toxic than the parent compound. The principal intermediates observed during the photocatalytic oxidation process of PCP were 2,3,5,6,-tetrachloro-1,4,-hydroquinone, 2,3,5,6,-tetrachloro-1,4,-benzoquinone and 2,3,5,6,-tetrachlorophenol. In the case of 2,3,5,-TCP and 3,5,-DCP, the identified intermediates were 2,3,5,-trichloro-1,4,-hydroquinone and 2,5,dichloro-1,4,-hydroquinone, respectively. The intermediates of 2,4,-DCP were not identified.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call