Wastewater treatment in packaging product processing plants
The wastewater treatment of packaging product processing plants mainly involves the treatment of water-based paint wastewater, as the wastewater generated during painting and cleaning processes usually contains high concentrations of organic matter and suspended solids. The following are common processing techniques and steps:
Wastewater treatment process
Preprocessing
Grille filtration: removes larger suspended solids and impurities.
Regulating tank: Mix wastewater from different sources and adjust the pH value to a suitable range.
Chemical treatment
Demulsification and flocculation: Demulsifier is added to destroy the stability of lotion, and then flocculant (such as polyaluminum chloride) is added to agglomerate the suspended solids into larger particles for sedimentation.
Sedimentation: Remove suspended solids after coagulation through a sedimentation tank to form sludge.
Biological processing
Introduce the supernatant after sedimentation into a biological treatment system (such as activated sludge or biofilm process) to further remove organic pollutants.
Deep processing
Filtration: Use a sand filter or activated carbon filter to remove residual suspended solids and organic matter.
Membrane separation technology: such as ultrafiltration or reverse osmosis, further purifies water quality, removes fine particles and dissolved solids.
Reuse or discharge
After multi-level treatment, wastewater that meets discharge standards can be safely discharged or reused in production processes such as equipment cleaning, achieving the recycling of water resources.
Characteristics and Effects
High organic load: Water based paint wastewater contains a large amount of organic components such as resins and pigments.
High chromaticity and high COD concentration: After treatment, it should be ensured that the effluent meets the national discharge standards to reduce environmental pollution.
Economic benefits: By reusing some of the treated water, the water cost of enterprises can be significantly reduced.
Through the above process, packaging product processing plants can effectively manage and treat wastewater, reduce environmental impact, and achieve resource reuse