Chemical identification and acute biotoxicity assessment of gaseous chlorobenzene photodegradation products.
In order to evaluate the ecological safety and feasibility of UV photodegradation processes for the treatment of halogenated aromatic hydrocarbons, the chemical composition and acute biotoxicity of gaseous chlorobenzene photodegradation products were investigated. Results showed that the main products of chlorobenzene photodegradation included hydrochloric acid, acetic acid, formic acid, phenol and chlorophenol. Roughly 64% of the removed chlorobenzene was converted into phenol, making it the most significant product formed. The types of byproducts suggested that two distinct reaction pathways might compete during the photodegradation process. Interestingly, it appeared that one of these pathways did not involve the direct photocatalytic oxidation of chlorobenzene. An acute biotoxicity assay measuring the inhibition of bioluminescence indicated that gaseous exhaust with overall higher toxicity was emitted after UV irradiation. The acute toxicity of the UV reactor exhaust gas was as high as EC(50)=13.5mg-Zn(2+)m(-3-)-gas. The increased toxicity mainly resulted from the conversion of chlorobenzene to more soluble toxic products and ozone production during the photodegradation process.
Wang
Can
C
Environmental Simulation and Pollution Control State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China.
Xi
Jin-ying
JY
Hu
Hong-ying
HY
D002722:Chlorobenzenes / Q000032:analysis* / Q000737:chemistry* / Q000633:toxicity; D005740:Gases / Q000032:analysis / Q000737:chemistry* / Q000633:toxicity*; D049449:Luminescence; D010782:Photolysis; D012995:Solubility; D014466:Ultraviolet Rays; D014835:Volatilization; D014867:Water / Q000737:chemistry
D002722:Chlorobenzenes; D005740:Gases; D014867:Water; C031294:chlorobenzene