1. Floating in the wastewater solids, such as leaves, peels, minced meat, poultry feathers, etc.
2. Suspended in the wastewater are substances such as fats and oils, proteins, starch, colloidal substances, etc.
3. Dissolved in the wastewater acids, alkalis, salts, sugars, etc.
4. Raw materials entrained in the mud and sand, as well as other organic matter, etc.
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5. Pathogenic bacteria and toxins, etc.
Handan Huojie environmental protection to introduce some of the treatment of food wastewater:
1, coagulation method
Colloidal substances in the water, usually with an electric charge, colloidal substances can not be coagulated with each other to exclude the formation of a stable mixture of liquids. If the water is added with the opposite charge of the electrolyte, the wastewater can make the colloidal material is neutral, destabilized, and under the action of molecular gravity, cohesion into large particles and sinking. Commonly used coagulants are polyacrylamide, aluminum sulfate, alum, polymerized alumina, ferrous sulfate, ferric chloride and so on. This method has the advantages of simple equipment, easy to implement, promotion and maintenance, but there are also high operating costs, slagging and other shortcomings.
2, neutralization method
The use of chemical methods to neutralize acidic wastewater or alkaline wastewater to achieve neutral methods. To acidic wastewater by adding alkaline substances such as lime, limestone, dolomite, etc., so that food wastewater becomes neutral. Alkaline food wastewater can be blown into the flue gas containing CO2 to neutralize, can also be neutralized with acid.
3, redox method
Wastewater in the dissolved organic or inorganic substances, in the addition of oxidizing or reducing agent, due to the migration of electrons, and the oxidation or reduction, into harmless substances.
4, electrolysis
In the wastewater inserted electrodes. Accepting electrons on the cathode plate, the ionic charge is neutralized and transformed into neutral atoms. The above integrated process causes oxidation to occur on the anode and reduction to occur on the cathode.
In addition to this, commonly used wastewater treatment methods include extraction, blow-off, adsorption, electrodialysis, reverse osmosis, etc.
5, extraction method
Water-insoluble solvent into the wastewater, so that the solute in the wastewater dissolved in the solvent, and then the use of solvents and the specific gravity of water, the solvent will be separated out. Then use the solvent and solute boiling point difference, the solute distillation recovery, regeneration of the solvent can be recycled.
6, blowing off method
Wastewater into the air, so that the soluble gas in the wastewater blown into the atmosphere. This method can be used for CO2, H2S, HCN wastewater treatment.
7, adsorption method
The wastewater through the solid adsorbent, so that the wastewater in the dissolved organic or inorganic substances adsorbed to the adsorbent, commonly used adsorbent for activated carbon. This method can be adsorbed wastewater phenol, mercury, chromium, cyanide and other toxic substances. This method also has excellent, decolorization and other functions. Generally used for wastewater depth treatment.
8, electrodialysis method
Electrodialysis is a process of transferring ions in solution through the membrane under the action of electric field. Wastewater through the anion and cation exchange membrane composed of electrodialyzer, wastewater in the anion and cation may be separated to achieve the purpose of concentration and treatment.
9, reverse osmosis
Through a special semi-permeable membrane, under a certain pressure, the water molecules will be pressed through, while the solute is retained by the membrane, the wastewater is concentrated, and the water that is pressed through the membrane is the water of the treatment process.
Related wastewater treatment industry Handan Howie environmental protection reminds us that for wastewater treatment of food manufacturers, the need for less investment, low operating costs, stable operation, good treatment results, easy operation and management of the treatment process, the choice of process must be considered in conjunction with their own actual situation.