Titanium Electrode for Printing and Dyeing Wastewater Treatm
发布时间：2019-06-29
Titanium Electrode for Printing and Dyeing Wastewater Treatment
Printing and dyeing wastewater is produced in the process of textile billet and sizing, boiling, desizing, bleaching, mercerizing, printing and dyeing of fiber materials. It contains naphthalene series, quinone series, amine compounds, sulfide, chromium, alkali, acid and other toxic and harmful substances.
Dyestuff wastewater has high chroma, complex composition and low biodegradability. After discharging, it has a great impact on surface water environment, especially the chroma destroys the landscape environment.
In recent years, direct electrolysis has opened up a new way for the treatment of dye wastewater. Electrolysis is the removal of organic matter and decolorization by electrolytic reaction, in which air flotation and flocculation are realized.
The process of removing dye molecules by electrolysis is actually the process of electrolysis-air flotation-flocculation. The cathode and anode react with electrodes. A flocculant with high adsorption activity is formed on the anode, which can effectively remove colloidal particles and impurities from dye wastewater. The H2 generated by the cathode can drive the flocs upward to the surface, and then precipitate after the reaction, which is an air floatation process. The oxidation or reduction reaction at the two poles can destroy the chromogenic groups of dye molecules, turn macromolecular substances into small molecular substances, or completely oxidize to CO2 and HO2, and the color of the solution becomes colorless.
The added electrolyte is NaCl, which helps to decolorize and remove COD from wastewater. The reason is that chlorine evolution occurs on the anode when NaCl solution is electrolyzed, and Cl2 is a strong oxidant. NaClO is further formed by Cl2, Na + and O2, and NaClO is more oxidative. Cl2 and NaClO are both strong oxidants, which can oxidize dye molecules and make the long bond broken and discolored. In addition, the addition of NaCl accelerated the hydrogen peroxide electrolysis, and the bubbles formed by H2 from the cathode moved upward with branches and flocculants, which accelerated the flotation and flocculation of organic matter.
Electrolysis has a good treatment effect on dye wastewater. The removal rate of COD-cr is over 90% and the decolorization rate is 100%.
