Phenylphenol isomers (hydroxylated derivatives of biphenyl) are widely used as a preservative agents and disinfectants in many branches of industry. This work focuses on removal of phenylphenol isomers from aqueous solution using H2O2/UVC process. The influence of different operating variables such as pH, initial concentration of hydrogen peroxide, initial concentration of target compounds, fluence rate and presence of radical scavengers on degradation rate was investigated. Moreover, transformation products and toxicity of the reaction solutions were studied. The reaction rate constants of hydroxyl radicals with phenylphenol isomers were determined by using classical and competition kinetics. The value of reaction rate constant depends on the position of the hydroxyl group in the aromatic ring and follows the order: ortho- phenylphenol

Keywords:Phenylphenols;H2O2/UVC system;Photodegradation kinetics;Toxicity assessment;Transformation by-products