engleski

UV-assisted persulfate oxidation: the influence of cation type in persulfate salt on the degradation kinetic of azo dye pollutant

With the aim to investigate the influence of UV-assisted persulfate oxidation operating parameters (cation type in persulfate salt, persulfate concentration and initial pH) the empirical/modeling approach applying full factorial experimental design (FFD) combined with response surface methodology (RSM) and mechanistic modeling (MM) was applied. The efficiency of UV-assisted persulfate oxidation as wastewater treatment method in dependence on aforementioned process parameters was evaluated in the case study where azo dye (C.I. Acid Orange 7 – AO7) was used as a model pollutant in water matrix. The FFD matrix with three independent variables representing studied process parameters established experimental combinations on which UV-assisted persulfate oxidation process response, AO7 decolorization rate, was determined and correlated using RSM over quadratic polynomial equations, i.e. RSM model. The significance and accuracy of such developed RSM model was evaluated on the basis of analysis of variance (ANOVA) and obtained statistical parameters (R2, F, p), used also to examined the influence of studied process parameters. It was determined that persulfate salt is the most influential process parameter, followed by rather high combined influence of initial pH and cation type, indicating the practical implications regarding the cation type. The mechanistic model used to describe UV-assisted persulfate oxidation system showed high accuracy in predicting AO7 degradation monitored over several parameters (decolorization, degradation of naphthalene and benzene structures, as well as overall mineralization) as well as high flexibility covering the broad pH range of application set by different cation type ion the persulfate salt.

persulfate; oxidation; UV irradiation; statistical modeling; kinetic modeling; azo dye

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