Method for treating oily wastewater in catering industry

Abstract

The invention belongs to the technical field of wastewater treatment, and particularly relates to a method for treating oily wastewater in catering industry. The invention provides the method for treating the oily wastewater in the catering industry with simple operation and good oil removing effect. The method comprises that (1) a polyferric sulfate demulsifying agent is added into the oily wastewater, the adding amount of the demulsifying agent is 0.2 to 2 milligrams per liter, and the mixture is stirred evenly, wherein the polyferric sulfate is cationic, reduces the surface activity of anionic detergent, and breaks hydrated films of emulsified liquid oil droplets and double electrode layer structures thereof so as to separate out oil; and meanwhile the polyferric sulfate is acid, and can covert fatty acid soap in the emulsified liquid into water-insoluble fatty acid so as to reduce surface active substances in the water and increase the demulsifying effect; (2) sodium humate flocculating agent and polyacrylamide are added into the wastewater obtained in the step (1), the adding amount of the sodium humate is 0.1 to 0.4 milligrams per liter, the adding amount of the polyacrylamide is 40 to 100 milligrams per liter, and the mixture is stirred evenly; and (3) the oil and the water are separated by using the gravity principle.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a treatment method for oily wastewater in the catering industry. Background technique [0002] In recent years, with the growth of the national economy and the rapid development of the catering industry, the amount of wastewater discharged is increasing. Because the wastewater contains high concentrations of animal and vegetable oils and a large amount of suspended solids, it has become an important source of water pollution. , the treatment of oily wastewater in the catering industry can not only protect the ecological environment, but also reduce the burden on urban sewage treatment stations, which has obvious environmental and economic benefits. The oily wastewater in the catering industry has a high amount of pollution, and the main pollutants are animal and vegetable oils, chemical oxygen consumption and suspended solids. At present, in the catering ...

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Problems solved by technology

[0003] The treatment methods of oily wastewater include: gravity separation method, which can remove oil with a particle size of more than 150 microns, stable operation, stable degreasing effect, and low treatment cost, but its disadvantages are that the pool is large, occupies a large area, and cannot remove emulsification Oil; centrifugal separation method, which can remove oil above 5um, has large processing capacity and high separation efficiency, but its disadvantages are high energy consumption and easy phase formation of dirt at the outlet; flotation method (air flotation method), high flotation efficiency and easy operation It is easy to control and has a mature process, but its disadvantages are high operating costs, large floor space, difficult to handle oil slicks, and a large amount of scum