Wastewater treatment technology for surface treatment of aluminum profiles

China currently has more than 600 aluminum profile production enterprises, producing more than 2 million tons of aluminum profiles each year, but also discharge a large amount of wastewater, causing serious environmental pollutionaluminum profile surface treatment water consumption, produce more wastewater, waste water in the continuous discharge of harmful substancesIf not treated, it will certainly pollute the environmentAt the same time, along with China's tax on sewage emissions, will also increase the cost and burden of enterprisesTherefore, from the social responsibility and efficiency of enterprises, wastewater treatment is necessary and necessaryThe author summarizes the experience of multi-year process research and management of aluminum profile surface treatment and wastewater treatment, and puts forward a set of practical wastewater treatment and reuse scheme for peer reference1, the source and type of aluminum profile surface treatment wastewateraluminum profile surface treatment wastewater has pre-treated oil and post-acid water washing, alkaline water washing after alkali corrosion, acidic water after acid erosion, acidic water washing after oxidation, after coloring containing Ni2, Sn2 plus, acidic water washing, electrophoresis painting ionic ionic exchange device produced waste acid, waste and alkali coating wastewaterThe wastewater is acidic when mixed, containing al3 plus, Ni2 plus, Sn2, Sn4 plus, Na, Cr3 plus cations, as well as anions such as SO42-, F-, NO3-, Cl-, AlO2-, Ac-and-Ac-and-Ac-other, as well as organic matter such as surfactants and propylene acid resinsWaste liquid has degreased and produced waste sulfuric acid, waste nitric acid and oxidation of waste sulfuric acid, coloring of waste liquid, electrophoresis paint produced by waste acrylic liquid, sealing hole produced with Ni2 plus, F-and other waste liquid2, reduce the discharge of waste water and waste liquidthe method of reducing waste water and waste liquid has reasonable control of water control time and control loading angle to reduce the amount of tank fluid out, as far as possible to use the second-level three-level reverse-flow rinsing, reduce water consumptionAcid erosion and degreasing after water washing is used for alkali corrosion after washing, after oxidation water washing is used for acid erosion and degreasing after washingIn addition, in order to reduce or avoid the discharge of waste water and waste tank liquid, the production line should design and use a variety of recycling devices, such as acid erosion recovery device, alkali erosion recovery device, anode de-alumina removal device, coloring liquid RO recovery device, electrophoresis paint RO recovery device, these recovery devices can reduce the amount of wastewater and waste liquid emissions to the maximum extent, but also minimize production costs3, aluminum profile surface treatment wastewater treatment principle and method
aluminum profile surface treatment of wastewater, mainly acid-base wastewater, containing Ni2, Sn2, F-and other small amount of harmful yin and yang ions, treatment method is acid-baseWastewater is generally acidic, to add alkali neutralize, adjust the PH value to 7 to 8.5 or so At the same time in the process of the cation of the cation al3 plus, Ni2 plus, Sn2 plus Cr3 , etc are formed hydrogen oxide precipitation After the intermediate and precipitation of wastewater pump into the condensed tank, at the same time with a quantitative pump into the dissolved polyamide flocculation and wastewater condensation, after condensation wastewater into the sedimentation tank, precipitation method has slope precipitation method, gas floating method, centrifugation precipitation method, etc , the author believes that the use of centrifugation precipitation method is relatively stable, after precipitation, the liquid from the upper overflow port overflow into the discharge tank or re-treatment of the reservoir After the above treatment of wastewater can be discharged to meet the standard, if the wastewater reuse, at this time the waste water can go through coarse filtration into the RO device for treatment, remove excess yin and yang ions, organic matter, at this time the water PH value may be low, can be adjusted by yin and yang ion exchange device to achieve reuse standards The sludge generated by precipitation is regularly discharged into the sludge pool, and after treatment by plate pie press or belt dewatering machine into industrial waste, it is fed into the industrial waste treatment plant Source: China Aluminum Network"