The food industry has a wide range of raw materials, a wide range of products, discharged wastewater water, water quality varies greatly. The main pollutants in the wastewater are:
(1) floating in the wastewater solids, such as leaves, peels, minced meat, poultry feathers, etc.;
(2) suspended in the wastewater are oil, protein, starch, colloidal substances, etc.
(3) dissolved in the wastewater acids, alkalis, salts, sugars, etc.
(4) raw materials entrained in the mud and sand, and other Organic matter, etc.
(5) Pathogenic bacterial toxins, etc. Food industry wastewater is characterized by high content of organic matter and suspended solids, easy to rot, generally no major toxicity. Its harm is mainly to make the water body eutrophication, so as to cause the death of aquatic animals and fish, prompting the organic matter deposited under the water to produce a foul smell, deteriorate water quality, pollution of the environment.