subject: Chlorine Dioxide In Dyeing Wastewater Treatment - Chlorine Dioxide, Printing And Dyeing Wastewater [print this page] Dyeing wastewater is harmful to China's current major, one of refractory industrial wastewater, the main pollutants Dye , Pulp, additives, fiber impurity, oil, acid and Inorganic Salt. Characterized by large waste water, water quality complex Organic High concentration, difficult to biodegradation, dark color and rapid changes in water quality without the law and so on, especially in the dye of the most polluted. The residual dye components even in small concentrations, can also cause water transmittance decreased, resulting in damage to the ecology.
Currently the treatment of dyeing wastewater and more dominated by biochemical and some are supported by the chemical method, but the prevailing cost of handling a large investment, operating costs are high, treatment results are poor, difficult color to remove the disadvantages. On this basis, using physical and chemical treatment methods of study more [1]. By coagulation [2], chemical oxidation [3], adsorption [4,5] and membrane technology [6] and so may remove some of the COD and color, which degree of oxidation on the removal of the most obvious. However, oxidation by-products (such as organic halides and epoxides) or operating costs and other issues make the use of chlorine and ozone has been limited.
Chlorine dioxide as a kind of strong oxidation and oxidation of organic halides in the few resulting oxidant [7] in the oxidation of water disinfection and paper and pulp bleaching industry and other industries has been widely used. In recent years, a new oxidant Cl02 people in wastewater treatment were also studied, and useful for Cl02, direct treatment of dyeing wastewater were reported. In this paper, printing and dyeing wastewater by chlorine dioxide treatment in the application of the status quo and development trend of the mechanism for a review and discussion.
1Cl02 the nature of the mechanism of bleaching
1.1Cl02 the nature of the
Cl02 is a class of chlorine gas, dissolved in water increase with the concentration of the color from yellow to green to orange red. In the 20cc, air pressure, water, chlorine dioxide concentration of 70mg / L. Chlorine dioxide gas at room temperature compressibility for the liquid density 2.4kg / L, boiling point of 11oC, melting point of a 59cc. Cl02 extremely unstable, volatile, decomposition, usually takes the C10, the first made of the stability of aqueous solution, the use of on-site Coupled with acidic activator after use or take C10: generator on-site plus a direct vote. When used for drinking water and sewage treatment, chlorine dioxide in solution form. Decolorization mechanism
1.2Cl02
Cl02 treatment of dyeing wastewater oxidation damage mainly to dye the hair color groups and help groups to achieve a significant bleaching effect. Under certain conditions, chlorine dioxide, with DPD (N, N 12-ethyl-p-phenylenediamine), cresol red (o-cresol sulfur phthalate), chlorophenol red (dichloro-sulfur phthalate), acid indigo (5 , 5 an indigo sulfonate, or salt, indigo San Juan, PR), Lisi amine Green B (aryl methane dye), Rhodamine B (tetraethyl Jiluodanming) and methylene blue color agent such as discoloration occurs. Indigo acid in pH
