Membrane method separation purification technology of emulsified oil-containing wastewater

Abstract

The invention discloses a membrane method separation and purification process for emulsified oily wastewater, which comprises the steps of: a. pretreating the emulsified oily wastewater by coarse filtration; b. using a feed pump to transport the filtrate to a circulation tank of ceramic membrane separation and extraction equipment , enter the membrane modules at all levels under a certain pressure for fine filtration; c. Add water dialysis in batches until the residual components in the concentrated solution are less than the specified value, and then post-process the concentrated solution; d. Separation and extraction through ceramic membranes The permeate treated by the equipment enters the intermediate tank B; e. Then the permeate enters the roll-type ultrafiltration membrane separation and extraction equipment to further remove bacteria, macromolecular proteins and pigments; f. After that, the permeate enters the intermediate tank C, and then uses sodium Membrane equipment concentrates it. The membrane method separation and purification process of emulsified oily wastewater provided by the invention has simple equipment and process, strong stability, long service life and cost saving.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a membrane separation and purification process for emulsified oily wastewater. Background technique [0002] At present, in iron and steel plants, in order to eliminate the deformation heat generated during cold rolling of strip steel, emulsions are often used as lubricants and coolants. The emulsion is mainly composed of 2%~10% mineral oil or vegetable oil, emulsifier and water. Since the emulsion is heated and evaporated by water, the salt content increases, the stability decreases, and it will also deteriorate due to oxidation or bacterial action. Therefore, it is necessary to continuously discharge a part of the old emulsion during use and replenish new emulsion. Generally, 2- It will be updated in 3 months. Certain treatment is required before discharge to remove oily substances in the wastewater. The general treatment methods include chemical method and organic...

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Problems solved by technology

However, due to the limitation of the material itself, there are certain restrictions on the control means of membrane fouling and the method of membrane cleaning, mainly due to the low flux and the difficulty in stabilizing the oil content of the effluent.

Due to the limitation of its material, the organic membrane is easily deformed, resulting in the change of the membrane pore size, which will eventually lead to unstable water quality of the permeate.

[0005] There are several sets of organic membrane emulsification oily wastewater treatment equipment imported from abroad in China. The main problems of imported organic membrane treatment technology are: a. The one-time investment of imported organic membrane equipment is large; b. The membrane tube is easy to age, about 2~3 It needs to be replaced once a year; c. The operation consumes a lot of energy, and the normal operation and maintenance costs are high; d. The treatment effect and membrane flux are unstable due to the concentration change of the cold-rolled emulsion wastewater, and it is easy to cause the flux to drop too fast and the retention rate low level problem

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