engleski

Structural aspects of degradation of sulfoaromatics by UV/H2O2 process

The influence of sulfoaromatics (SulfoArs) structure on photooxidative treatment by UV/H2O2 process was investigated. In that purpose, typical SulfoArs water pollutants ; benzenesulfonic acids with different substituents in para position (-H, -OH, -CH3, -Cl, -NH2) were chosen: BSA, HBSA, TSA, CBSA and ABSA, respectively. Effect of UV/H2O2 process parameters and structural features of SulfoArs on their degradation kinetics was investigated by statistical/empirical approach employing design of experiments and response surface methodology. Different optimal conditions for maximal degradation rates were established. The observed degradation rate constants and reaction rate constants of SulfoArs with hydroxyl radicals follow the different decreasing orders indicating on the competitive kinetics with by- products formed through the structurally influenced degradation pathways. The mineralization kinetics is correlated with the degradation pathways of studied SulfoArs, the shared sequence within, and influence of inorganic ions present in the reaction mixture upon elimination of parent substituents. It was determined that changes of biodegradability and toxicity toward Vibrio fischeri during UV/H2O2 treatment are related to the preferable degradation route including the elimination of parent substituent and subsequent hydroxylation. In the observed treatment period biodegradability was significantly improved in all cases, while the toxicity levels were higher than that of parent pollutants.

sulfoaromatics; photooxidation; response surface modeling; degradation kinetic; biodegradability; toxicity

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