| The treatments of the simulated Ammonium-Nitrogen wastewater and Azo Dye wastewater were experimentally researched using the three-dimensional electrode reactor which was designed for this thesis. The effects of cell voltage, concentration of Electrolyte, original pH value and concentration of wastewater were investigated. Furthermore, ultrasonic was put into the system in order to improve the effect of degradation. Simulated Ammonium-Nitrogen wastewater and Azo Dye wastewater were degraded by the three-dimentional electrode reactor coupling ultrasonic.
The experimental results indicated that the pollutants could be electrochemically oxidized in a much better way using the three-dimensional electrode reactor than using the conventional two-dimensional electrode reactor because of the significant enhancement of the electrode surface area. Compared with the two dimensional electrode reactor, the removal rate of Ammonium-Nitrogen was improved by 45.3% using the three-dimensional reactor. While the removal rate decreased with the increase of the initial concentration of Ammonium-Nitrogen, the removal amount increased. When the cell voltage is 7.0V, the concentration of electrolyte is 0.20mol·L-1 and the original pH is 7.00, the removal rate of Ammonium-Nitrogen approached 96.4% after 4 hours’ electrochemical oxidation. Furthermore, when the Ammonium-Nitrogen wastewater was treated by the three-dimensional electrode reactor coupling ultrasonic, the removal rate increased by 86.8% and 28.5% respectively compared with the conventional two-dimensional electrode and the three-dimensional electrode reactors. Under optimum conditions, the removal rate of Ammonium-Nitrogen exceeded 99.0%.
The treatment of wastewater containing Methyl Orange was researched using the three-dimensional electrode reactor. The results showed that, by contrast experiment, the removal rate of CODCr was improved by 86.4% compared with the two-dimensional electrode reactor. When the cell voltage is 9.0V, the concentration of electrolyte is 0.20mol·L-1 and the original pH is 4.00, the removal rates of Methyl Orange and CODCr reached 95.7% and 84.3% respectlively after 150 minutes’ degradation. Furthermore, compared with the two-dimensional and the three-dimensional electrode reactors, the removal rate of CODCr was enhanced by 1.57 times and 37.8% using the three-dimensional electrode reactor coupling ultrasonic. The removal rate of Methyl Orange exceeded 99.0% and the removal rate of CODCr approached 90.0% under optimum conditions after 120 minutes’ degradation. According to the Ultraviolet-visible and Infrared Spectral changes during degradation of Methyl Orange, it can be presumed that the removal of CODCr lags behind the removal of methyl orange for the reason that the structure of benzene ring is more difficult to destroy compared with the azo double bonds.
Keywords: Titanium anode, Three-dimensional electrode, Electrochemical oxidation, Ultrasonic, Methyl Orange, Ammonium-Nitrogen