The PET bottle washing line is mainly used for cleaning and recycling waste PET bottles; The pet bottle washing recycling line takes steps such as unpacking, crushing, removing trademark paper, pre washing, separation and cleaning, dehydration, and automatic filling of PET bottles to obtain pure PET bottle slices; During the crushing and cleaning process of PET waste plastic bottles, a large amount of cleaning wastewater will be generated. What should we do with this sewage. Is it directly discharged or continuously used.
When the waste plastic bottle cleaning water becomes dirty to a certain extent and cannot be used anymore, it is necessary to replace it with clean water. How to treat these waste plastic cleaning wastewater? If discharged directly, it will cause pollution to the surrounding environment, which is not allowed by law. What method and equipment should be used to treat plastic washing wastewater? Can the wastewater treated by plastic washing wastewater treatment equipment be reused to save costs? Coagulation treatment can be used to remove most suspended solids from wastewater, and then reuse the wastewater in production processes to achieve the goal of reducing wastewater emissions. The discharged sewage can be mixed with domestic sewage to improve its biodegradability, and then discharged after biological treatment.
1, Introduction to Pollutants in PET washing line Wastewater: Organic Pollution: Waste plastic mainly comes into contact with or has been packaged in food, feed, beverages, etc. PH pollution: Alkaline substances mainly added during the crushing and cleaning process of waste plastics. Suspended substance pollution: Waste plastic agricultural film and greenhouse film mainly contact or package chemical fiber soil dust, waste plastic particles, etc. Grease pollution: Waste plastic PET bottles mainly come into contact with or have been packaged with grease substances.
2, The treatment methods for PET plastic cleaning wastewater in Weifang Hengwo Chuangke Environmental Protection Wastewater Treatment are mainly divided into three categories: physical treatment, chemical treatment, and biological treatment.
1. Physical treatment method: A wastewater treatment method that separates and recovers insoluble suspended pollutants (including oil film and oil beads) from wastewater through physical action. Generally, sedimentation, filtration, centrifugal separation, air flotation, evaporative crystallization, reverse osmosis, and other methods are used to separate pollutants such as suspended solids, colloids, and oils from wastewater, thereby preliminarily purifying the wastewater.
2. Chemical treatment method: A wastewater treatment method that separates, removes, or converts dissolved or colloidal pollutants from wastewater into harmless substances through chemical reactions and mass transfer. The commonly used methods include neutralization, coagulation, redox, extraction, stripping, stripping, adsorption, ion exchange, and electroosmosis.
3. Biological treatment method: A method for treating wastewater that converts wastewater solutions, colloids, and finely suspended organic and toxic substances into stable and harmless substances through the metabolic action of microorganisms. Biological treatment methods are divided into aerobic treatment and anaerobic treatment. Currently, aerobic treatment methods commonly used include activated sludge method, biological filter, and oxidation pond. Anaerobic treatment method, also known as biological reduction treatment method, is mainly used to treat high concentration organic wastewater and sludge, using treatment equipment, mainly digestion tanks, etc.
3, PET plastic cleaning wastewater treatment process: The plastic cleaning wastewater passes through a basic sedimentation tank or grid and enters a biological tank, where it can be adjusted to be aerobic or anaerobic to create a favorable environment for microbial growth. The carrier filler forms a fluidized bed in the vortex of the aeration zone, which is well dispersed and suspended under the stability of the anaerobic/aerobic fluidized bed in the non aeration zone. The shear force existing in the vortex ensures the high activity of the biofilm. Therefore, the stable carrier of the maintenance system can meet the process requirements without hindrance. In the secondary sedimentation tank, activated sludge and clear water are precipitated and separated, and part of the sludge is returned to the biological tank as reflux sludge, while the other part of excess sludge enters the sludge tank. Clear water flows out and is discharged to achieve the purpose of wastewater purification.
After passing through a basic sedimentation tank or grid, the wastewater enters a biological tank, where an adjustable aerobic or anaerobic environment suitable for microbial growth is established. The carrier filler forms a fluidized bed in the vortex of the aeration zone, which is well dispersed and suspended under the stability of the anaerobic/aerobic fluidized bed in the non aeration zone. The shear force existing in the vortex ensures the high activity of the biofilm. Therefore, the stable carrier of the maintenance system can meet the process requirements without hindrance. In the secondary sedimentation tank, activated sludge and clear water are precipitated and separated, and part of the sludge is returned to the biological tank as reflux sludge, while the other part of excess sludge enters the sludge tank. Clear water flows out and is discharged to achieve the purpose of wastewater purification.