engleski

Modeling of photodegradation kinetics of aromatic pollutants in water matrix

In this study photodegradation kinetics of aromatic pollutants in water was simulated by combining two approaches: kinetic modeling and structural-relationship modeling. Semiempirical model based on Lambert’s law (“LL model”) was used to determine quantum yields (Phi of 28 single- benzene ring pollutants. QSAR/QSPR modeling, using Genetic Algorithm (GA) and multiple regression analysis (MLRA) to select the descriptors and to generate the best correlation models, was applied to establish structure-property relationship of molar absorption coefficient (ε) and quantum yield (Phi). In both cases the most predictive models consistent of 4 variables, i.e. descriptors, possessing the good ratios of the number of variables and the predictive ability to avoid overfitting. It was found that ε depends on the overall number of bonds, particular atom-centered fragment related to substituents possessing double and single bonded heteroatoms (O or N) to C atom, as well as the shape and size of the molecule and polarizibility. Molecular symmetry was shown as the most influential factor toward Phi. The applied GA-MLRA approach using DRAGON generated descriptors yielded good results, which was also confirmed by external validation. “LL model” simulation for two additional single-benzene ring pollutants, using predicted Phi and ε by QSAR/QSPR, slightly deviated from the experimental results (RMSD≤0.75%).

aromatic pollutants ; water matrix ; photodegradation ; kinetics ; structural relationship

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