Food Processing Wastewater Treatment

DAF Dissolved Air Flotation Machine for Food Processing Wastewater Treatment
Food processing industry has a wide range of raw materials and a wide variety of products, and the amount and quality of discharged wastewater vary greatly. Therefore, the wastewater generated in food processing needs to undergo a series of treatments to ensure no damages to natural environment before wastewater discharging.

Main pollutants in food processing wastewater are:
1. Substances floating in wastewater, such as vegetable leaves, peels, ground meat, feathers, etc.
2. Substances suspended in wastewater, such as fats, proteins, starch, colloidal substances, etc.
3. Acids, alkalis, salts, sugars, etc. which are dissolved in wastewater.
4. Mud, sand and other organic matter entrained in raw materials.
5. Pathogenic bacteria.

Food industry wastewater is characterized by high content of organic substances and suspended solids, easy to spoil, and generally no great toxicity. Its main harm is eutrophication of water bodies, which causes the death of aquatic animals and fish, and promotes the odor of organic matter deposited on the bottom of the water, which deteriorates the water quality and pollutes the environment.

Feed food processing wastewater to dissolved air flotation machine by pump. And dose flocculant and coagulant into and thoroughly mix with wastewater for flocculation reaction to coagulate the oil & grease, colloidal particles and micro suspended solids to conglomerate the particles into bigger clusters.

Dissolved air flotation machine will release millions of tiny bubbles into water, these bubbles attach to, and form within, the solids or chemical flocculants entering the vessel, causing them to float to water surface where they are retained and forms scum layer, which is then subsequently removed by DAF skimmer.

The micro bubble releasing process is also an oxidation process, which transfer oxygen from air to wastewater, greatly reduce the odors from spoilage of organic matters. Dissolved air flotation machine removes the most part of suspended solids (TSS), also will remove part of BOD and COD, greatly reduce the pollution loads for the subsequent biological treatment process.