subject: Technical Papers: Application Of Dye Wastewater Treatment [print this page] Chemical methods (chemical coagulation, chemical oxidation, wet oxidation, photocatalytic oxidation), biochemical, electrochemical characteristics, principles and recent progress and application. Dye production process complicated and difficult to handle waste water volume, high cost of pollution control, only to fundamentally reduce emissions, is a permanent solution.
Keywords: Dye Wastewater Law electrochemical chemical and biochemical methods
Textile dye industry in recent years, rapid development and now a variety of dye production in China reached 900 000 t, wastewater pollution has become the focus of one of the environment. Dye industry, variety, craft complex. The waste water contains large amounts of organic matter and salt, with CODCr high color depth, and strong acid-base characteristics, has been a wastewater treatment problems. This paper introduces the wastewater treatment technology in the physical, chemical, electrochemical, biochemical and technological characteristics of these principles and recent research progress and application.
1 physical methods 1.1 assay Adsorption method is the use of porous solids (such as Activated Carbon , Adsorption resin, etc.) and the dye wastewater treatment with the use of adsorbent surface activity, the dye wastewater and organic compounds and metal ions concentration on its surface, to achieve the purpose of purifying water.
Activated carbon with high adsorption capacity of cationic dyes, direct dyes, acid dyes, reactive dyes and other water-soluble dye has a good adsorption capability, but activated carbon is expensive, not easily renewable. By the chitosan and cellulose mixed with activated carbon made from reactive dyes and acid dyes on the adsorbent has excellent adsorption capacity, the adsorption capacity was 264 and 421mg / g (coconut activated carbon adsorption capacity of less than 80mg / g). The adsorbent in the water with excellent dispersion, can use simple and inexpensive access to filtration method.
Macroporous resin was submitted to the internal network structure of the polymer beads together like body, with excellent pore structure and high specific surface area. Resin can be used for biological treatment to remove hard aromatic sulfonates, naphthalene phenols. It is easily recycled, and the physical and chemical stability, resin adsorption treatment of dye wastewater has become one of effective methods.
1.2 Membrane Separation Membrane separation technology for wastewater treatment is mainly ultrafiltration and reverse osmosis. According to reports, with the tube and hollow fiber polysulfone Membrane Reduction of dye wastewater treatment rate from 95% to 98%, CODCr removal of 60% to 90% dye recovery was more than 95%. In recent years, with the chitosan ultra- Membrane And porous carbon membrane of new membrane material to handle printing and dyeing wastewater, to achieve good results. Xia Ning, studied the role of wastewater by ultrasound, through cellulose acetate membranes and through the salt water permeability rate of ultrasound in membrane separation was found significantly to accelerate the mass transfer and "concentration polarization" effect, with the role of ultrasound The penetration rate is no ultrasound was 1.5 times greater impact on the rate of penetration of salt, the rejection rates were 94% and 67%.
2 chemical 2.1 Chemical coagulation
Chemical coagulation mainly precipitation and air float, this method is cost-effective, but the chemical in the sludge for further processing. Commonly used are inorganic salts of iron compound. Polymer used at home and abroad in recent years Coagulant Increasing. Natural polymer flocculant mainly starch and starch derivatives, chitin derivatives and lignin derivatives of 3 categories. Zeng Shulan with NaOH as a catalyst such as corn starch and ether agent M reaction of the cationic starch CST, the dosage of 7 ~ 15mg / L, the acid dyes, reactive dyes decolorization rate was 90%. Wu Bingyan such as graft polymerization obtained with quaternary ammonium salts of lignin J acid dyestuff wastewater treatment flocculants, flocculant in the quaternary ammonium ion and wastewater generated in the acid group of substances insoluble in water, dosage 20mg / L, color removal efficiency was 90%.
Technical Papers: Application Of Dye Wastewater Treatment
