Food factory wastewater is a kind of industrial wastewater, which is characterized by high organic content, high suspended solids content, and contains pollutants such as pathogenic bacteria. If this type of wastewater is discharged directly into the environment without treatment, it will cause serious damage to the aquatic ecosystem, affect water quality safety, and even threaten human health. Therefore, it is crucial to adopt effective wastewater treatment processes.
Washing, cutting, cooking, pickling, fermentation, packaging and other links in the food production process
1. High organic content: The wastewater contains a large amount of organic matter such as carbohydrates, proteins, and fats, and the chemical oxygen demand (COD) and biochemical oxygen demand (BOD) are usually high.
2. Rich in suspended solids: Including food residues, peels, leaves, minced meat, etc., the suspended solids content in the wastewater is very high.
3. Large changes in water quality and water volume: Food production is seasonal and intermittent, and the amount of wastewater and water quality generated fluctuate greatly at different times.
4. May contain pathogenic bacteria: If the hygiene control in food processing is not proper, the wastewater may contain pathogenic bacteria, posing a potential threat to the environment and human health.
1. Pretreatment stage
Grate slag removal: Use mechanical grates to intercept large suspended matter.
Oil separation and sedimentation: Remove grease through the oil separator, and remove part of the suspended matter through the sedimentation tank.
Coagulation and flotation: Add Polyaluminum chloride(PAC) as a coagulant to form flocs with colloidal particles in the wastewater, which are then removed by flotation. PAC can effectively reduce the content of suspended matter and organic matter in wastewater. Polyacrylamide(PAM) as a coagulant can enhance the coagulation effect and improve the removal efficiency.
2. Biological treatment stage
Anaerobic treatment: Use processes such as hydrolysis acidification tanks and UASB anaerobic reactors to use anaerobic microorganisms to degrade organic matter and produce harmless substances such as methane. Anaerobic treatment can significantly reduce the concentration of organic matter and create favorable conditions for subsequent aerobic treatment.
Aerobic treatment: using activated sludge method, biofilm method, SBR, A/O and other processes, using aerobic microorganisms to further degrade organic matter and remove pollutants such as ammonia nitrogen. During the aerobic treatment process, oxygen is provided by the aeration device to ensure the normal metabolism of microorganisms.
3. Deep treatment stage
Sand filtration: remove suspended matter and particulate matter from wastewater.
Disinfection: using chlorine dioxide, ultraviolet rays and other disinfection methods to kill pathogenic bacteria and viruses.
Membrane separation (optional): for occasions with higher water quality requirements, membrane separation technologies such as ultrafiltration, nanofiltration and reverse osmosis can be used to further purify wastewater.
Using the combined process of "grid + oil separation sedimentation + coagulation flotation (PAC+ PAM) + anaerobic + aerobic + sand filtration + disinfection", the COD, BOD, SS, ammonia nitrogen and other indicators of ham and sausage factory wastewater after treatment can meet national and local emission standards.
At the same time, by optimizing the coagulation sedimentation and flotation process, using PAC and PAM to improve the removal efficiency and reduce the treatment cost.
In addition, part of the treated wastewater can be reused for workshop cleaning, equipment cooling, etc., further reducing production costs and water consumption.
In summary, Polyaluminum chloride(PAC) and Polyacrylamide(PAM) play an important role in the treatment of wastewater in ham and sausage factories. By optimizing the treatment process, not only the wastewater treatment efficiency is improved, but also the effective use of resources and cost reduction are achieved.
