Feasibility Study On UV-based Advanced Oxidation Process For The Degradation Of Chlorobenzene And Cyclohexanone

Based on the project of wastewater treatment for chemical industrial area inWenshang, Shandong province, this thesis is focused on engineering application ofadvanced oxidation in industrial wastewater treatment. Several aspects are included asfollows. The feasibility of UV-base advanced oxidation processes for the degradation ofchlorobenzene and cyclohexanone is demonstrated. After analysis on each influencingfactors, the process flow scheme and parameters of design and operation are optimized.In the end, we carry out analysis on operating test and economic indicators.Degradation of chlorobenzene and cyclohexanone using oxidation UV, H O andUV/processes is investigated. The degradation efficiency of UV/H O is better than only UV and H O. The UV/H O system for chlorobenzene reaction has two distinctphases marked as phase I and phase II. In the first phase H O concentration is thecontrolling factor in the degradation process, whereas in the second phase concentrationof intermediates is the controlling species. The reaction rate constant are9.8×10-3s-1and3.7×10-3s-1.However, A pseudo-first order kinetic model was adopted to representthe UV/H O system for cyclohexanone reaction. The reaction rate constant is1.2×10-4s-1.The effect factors such as UV wavelengths, UV intensity, H O initialconcentration, pollutants initial concentration and initial pH are investigated using bothLPUV/H O and MPUV/H O processes. MPUV/H O was found to degradechlorobenzene and cyclohexanone more rapidly than LPUV/H O. The high UVintensity and the UV wavelengths that are easier to be absorbed by H O, contaminantand intermediate may improve effects and reaction rate. Through summarize the dosageof UV and H O, the EEO of chlorobenzene and cyclohexanone, the effluentconcentration of chlorobenzene and cyclohexanone, it is conclusion that the optimaldoses of hydrogen peroxide at this industrially relevant is20mg/L. Pollutants initialconcentration increases with reaction rate logarithmly. The pH under acidulous andneutralconditions has advanced to increase reaction rate.This chemical industrial wastewater treatment plant of water is10000ton per day.The total dose of MPUV light is216kW. According to the design parameters, the AOPsystem requires three parallel trains of two MPUV reactors in series,(6reactors in total). The dosage of each reactor is above720mJ/cm2. The Lindustrial effluent is1.43s. Thedosage of H O is0~30mg/L. Using batch feeding method makes the H O utilizationrate more efficiently. In actual operation, the removal rate of COD is between22%and37%.The technical economic indicator of UV-based advanced oxidation process isanalyzed. The Electrical Energy per order (EEO) and UV dose.The EEO of theMPUV/H O system is lower than that of the LPUV/H O system for the removal ofCOD in actual operation. To the treatment scale is420m3/h, the equipment cost is4million yuan and the installation cost is300,000yuan. The total operation cost is0.638~0.774yuan.