Removal of Non-biodegradable Contaminants from Colored Textile Wastewater Using Electro Oxidation Process

Eftekhary, Sajjad | 2021

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 54127 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Borghei, Mehdi; Ghasemi, Shahnaz
  7. Abstract:
  8. In the present study, the electrochemical oxidation process was introduced as a green process for complete degradation and removal of non-biodegradable pollutants from aquatic environments and effluents of various industries without the need to use chemicals and toxins. Research stages include comprehensive preliminary studies in the field of electrochemistry and wastewater treatment, software design of electro-oxidation reactor using titanium mesh anode and stainless steel cathode mesh inside a body made of polypropylene, designed cell construction and then evaluation of device performance in polluting environment Are different. In software simulation using COMSOL MULTIPHYSICS software, it was found that by changing the inlet flow to 1.3 liters per minute, it is possible to prevent the formation of dead spaces inside the reactor to a good extent and achieve proper hydrodynamic distribution and mass transfer. It was found that the decrease in concentration near the reactor walls due to longer retention time and therefore more contact with the electrode surface, is more severe. The effect of various factors affecting the performance of the system such as electrolyte and electrode along with different operating conditions, was evaluated using the design of various experiments and the results of reducing the wastewater pollution load after each test. Introducing the optimal operating conditions of the device by examining various economic and environmental aspects by introducing the specific energy consumption parameter, per COD unit per unit time. In summary, it was found that the designed reactor is capable of optimal performance by applying current density, with optimal energy consumption and at a time constant of 8 minutes (in order to reach the initial COD) from within 1 liter of medium containing azo dye base red 46 and It also has a 4-fold electric current for dyeing wastewater in order to achieve the desired removal rate at a time constant of 15 minutes. The main challenge of research on titanium corrosion was introduced as an anode, which reduces the functional capacity of the cell and requires further research in the field of corrosion-resistant electrodes with electrocatalytic properties in the destruction of organic species. The average corrosion rate of titanium electrode was calculated to be about 0.15% per hour of use, which with the corrosion limit of 5% can be used continuously for 33 hours of useful operation. Also, the use of Ti / IrO2-Ta2O5 coated electrodes did not lead to proper efficiency due to the lack of electrocatalytic properties of these coatings against oxidation of organic species despite zero corrosion
  9. Keywords:
  10. Electrochemical Oxidation ; Corrosion ; Titanium ; Chemical Oxygen Demand (COD) ; Textile Effluent ; Dye Wastewater ; Hydroxyl Radical

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