[China Aluminum Industry Net] aluminum profiles have a large amount of water for disposal, and there are a lot of waste water, and harmful substances in the waste water continue to be discharged. If not treated, it will pollute the environment. Along with China's tax payment on sewage emissions, it will also add to the cost and burden of the company. Therefore, considering the company's social responsibility and benefits, it is necessary and necessary to carry out wastewater treatment. The author summarizes the years of experience in the technical research and handling of aluminum profiles for surface treatment and wastewater treatment, and proposes a practical and feasible wastewater disposal and reuse plan for their counterparts.
1. The origin and type of waste water treated by aluminum profiles. The waste water treated by aluminum profiles has the pre-disposal degreasing medium and acidic water wash water, alkaline water wash water after alkaline corrosion, acid water wash water after acid etching, and acidity after oxidation. Washed water, colored Ni2+, Sn2+, acidified water, electrophoretic paint ion exchange equipment waste acid, spent alkali and a few electrophoretic paint wastewater. Wastewater is acidic after mixing, rich in cations such as Al3+, Ni2+, Sn2+, Sn4+, Na+, Cr3+, and anions such as SO42-, F-, NO3-, Cl-, AlO2-, Ac-, as well as active agents and acrylics. Acid resin and other organic substances. Waste liquids include waste sulfuric acid produced by degreasing and neutralization, waste sulfuric acid produced by waste nitric acid and oxidation, waste liquid generated by coloration, waste acrylic acid solution generated by electrophoretic painting, and waste liquid including Ni2+ and F- generated by sealing.
2. Methods for reducing waste water and waste liquids The measures for reducing waste water and waste liquids include rational control of water control time and handling of loading angles to reduce the amount of tank liquid carried out, and use secondary three-stage countercurrent rinsing to reduce water consumption. After the etching and degreasing, the washed water is used for washing after alkali etching, and the washed water after oxidation is used for acid etching and washing after degreasing. In order to reduce or prevent the discharge of waste water and waste bath fluids, the production line should plan and use a variety of recovery equipment, such as etchback equipment, alkali recovery equipment, anodizing aluminum removal equipment, pigmentation liquid RO recovery equipment, electrophoresis Paint RO retraction equipment, the use of these retrieving equipment can be used to reduce the amount of waste water and waste discharge to a larger limit, together with a greater limit to reduce production costs.
3. Principles and Methods for Disposal of Wastewater from Disposal of Aluminum Profiles Wastewater from the external disposal of aluminum profiles is mainly acid-alkali waste water, and is rich in Ni2+, Sn2+, F-, and other harmful anions and cations. The disposal method is acid and alkali neutralization. The waste water is usually acidic and must be neutralized with alkali. The pH is adjusted to 7 to 8.5. Together in the neutralization process, the cations Al3+, Ni2+, Sn2+, Cr3+, etc. all constitute hydroxide deposition. The neutralized and deposited wastewater is pumped into the agglutination tank, together with a quantitative pump to dissolve the dissolved polyamide flocculant and the wastewater is agglutinated. After the agglutination, the wastewater enters the sedimentation tank. The sedimentation method includes sloping plate deposition and air flotation. The method of centrifugal sedimentation, etc., I believe that the centrifugal sedimentation method is still relatively stable. After sedimentation, the clear liquid overflows from the upper overflow port and enters the discharge tank or the reservoir. Wastewater passed through the above disposal can be discharged. If wastewater is reused, the waste water can be processed by coarse filtration into the RO equipment to remove residual anions and cations and organic matter. The PH value of the water at the moment can be low and can be passed. Anion and cation exchange equipments are adjusted to reach reuse specifications. The sludge that has been deposited has been discharged into the sludge pool at regular intervals. After being processed by a plate compactor or a belt dehydrator, the sludge is treated as an industrial waste residue and sent to the industrial waste residue disposal plant.