engleski

Treatment of Simulated Wastewater from Petrochemical Industry: Influence of Operating Parameters and Development of Mechanistic Model

Efficient solutions for the treatment of industrial wastewater ensuring its reuse and/or decreasing the pollution to the acceptable standards for discharging in the natural effluents are matters of unappreciable interest. One of the industrial sectors presenting a serious threat to the surrounding eco-system is petrochemical industry, where wastewater constituents pertain to both aromatic and aliphatic compounds, highly varying in their structures and can be highly toxic and present at high concentrations inhibiting the biological treatment. The aim of the study was to investigate the application of the photo-Fenton process for the treatment of simulated industrial wastewater originated from 1, 2-DCA/VCM plant (DINA Petrokemija Ltd, Omisalj, Croatia) upon pretreatment by the dark-Fenton process. The photo-Fenton process efficiency depends on several important process parameters such as initial pH, iron catalyst and oxidant concentration, and the type of UV irradiation. To consider the combined effects of influencing process parameters and to find optimal conditions, three-factor three-level Box-Behnken experimental design combined with response surface modeling was applied. The quadratic models predicting the mineralization of simulated industrial wastewater by the applied photo-Fenton processes were developed and ANOVA was applied to evaluate the significance of models and models’ components. The obtained results indicated that models can be characterized as highly accurate and predictive for the mineralization of simulated industrial wastewater. Our results showed that photo-Fenton process can be successfully applied for the treatment of the studied simulated industrial wastewater. The presence of oxalates in simulated industrial wastewater strongly influenced the conditions for the maximal efficiency of applied photo-Fenton processes regarding the type of UV irradiation. In order to predict the detailed system behavior, a mechanistic model simulating the influence of various factors: the type of UV irradiation, the changes in concentrations of pollutants, catalysts and oxidant and including pH dependent equilibrium of ferrous, ferric, oxalate and formate specie, on photo-Fenton process performance was developed. According to the obtained results, the developed mechanistic model describing the behavior of photo-Fenton process treating simulated wastewater can be characterized as interpretable, transparent, flexible and accurate and can be used in further intensification of treatment process. The comparison of electrical energy costs for each of the studied processes was performed. The obtained results indicate that the process using UV-C source is more efficient and cheaper. However, the simulation of process effectiveness using the solar UV-A irradiation recorded at annual basis for the location of proposed wastewater treatment plant speaks in the favor of solar UV-A/Fe/H2O2 process application instead of artificial UV irradiation.

industrial wastewater; photo-Fenton; ferrioxalate; process optimization; statistical analysis; kinetic modeling

nije evidentirano