Car painting workshop wastewater treatment method
degreasing, phosphating two water-saving units final discharge water, after dealing with the RO reverse osmosis unit, the RO water for respectively for watch before the final fresh water spray cleaning and final fresh water spray washing after phosphating, implements the pretreatment without waste water discharge or a small amount of emissions. Due to skim after washing and water washing after phosphating requirement for water quality is different, generally skim water level 1 reverse osmosis device for the unit, phosphating water-saving units must adopt two-stage reverse osmosis unit, figure 2 is a pretreatment RO recycle system schematic diagram.
2. Electrophoresis to discharge water processing
the current electrophoresis system of UF filter recovery technology, has been adopted to realize the closed cycle of electrophoresis and UF liquid washing system, but the last level of pure water to wash because there is fresh water spray cleaning adding, pure water tank overflow discharge, so the electrophoresis system generally there are still a lot of waste water discharge. Current implementation electrophoresis equipment there are two kinds of discharge water reuse schemes.
( 1) In the electrophoresis system increase RO reverse osmosis devices, ED - as UF ultra filtrate RO system of raw water, the ED - RO reverse osmosis system, strong water adding to UF3 groove, the pure water as the final stage of fresh produce gush to drench water, pure water tank overflow water is adding to the UF3 groove, so as to realize the closed loop of all electrophoresis process, can realize zero discharge waste water.
( 2) To the overflow of the pure water to wash the discharge water as the raw water of RO system, after RO reverse osmosis system, concentrate adding to UF3 groove, regeneration of pure water as the level of fresh water spray.
3. Discharge water spray equipment processing
paint circulation tank is the newest development direction of slag system using ultrafiltration and reverse osmosis and other advanced membrane separation technology, add a small amount of chemicals will be circulating water into the emulsion liquid, paint particles by ultrafiltration and reverse osmosis, solvents, salts, etc. , thus greatly reduce the emissions of waste water, and recyclable effective ingredient of the paint.