Treatment method and treatment system for cold-rolling oily wastewater

Abstract

The invention discloses a treatment method and a treatment system for cold-rolling oily wastewater. The treatment method comprises the following steps: (1) firstly, successively carrying out biological treatment and flocculent settling on the cold-rolling oily wastewater, and then introducing into a storage tank; (2) transferring the wastewater in the storage tank to an ultrafiltration device forfiltration; (3) introducing filtrate obtained after treatment by the ultrafiltration device into an alkalinity adjusting tank to adjust the pH value of the effluent to 6-8, and then introducing into a first intermediate water tank; (4) conveying the water in the first intermediate water tank into an electric absorption device for treatment, and after treatment, introducing into a second intermediate water tank; (5) after treating the water in the second intermediate water tank with a filter, introducing into a third intermediate water tank; and (6) conveying the water in the third intermediate water tank into a reverse osmosis treatment device for treatment and then conveying the effluent to a pure water tank. Through the treatment method and treatment system disclosed by the invention, the water quality can reach the requirements of cold-rolling production water, the recycling rate of the wastewater is high and a lot of water resources are saved.

Description

technical field [0001] The invention relates to the field of wastewater treatment, in particular to a cold rolling oily wastewater treatment method and system thereof. Background technique [0002] Metallurgical enterprises produce a large amount of oily wastewater in the steel rolling process, and its sources can be roughly divided into the following three parts: [0003] One is that in the strip rolling process, in order to eliminate the thermal deformation caused by cold rolling, it is necessary to use emulsion for cooling and lubrication, and the resulting cold rolling emulsion wastewater. The adopted emulsified liquid is mainly composed of 2-10% mineral oil or vegetable oil, anionic or nonionic emulsifier and water. [0004] The second is that the cooling strip steel will be degreased with alkaline solution before unwinding and annealing, resulting in a large amount of alkaline oily waste water. The main components of the alkaline solution used are sodium hydroxide, s...

AI Technical Summary

Problems solved by technology

General oily wastewater treatment methods, such as air flotation, adsorption, biological, chemical, etc., are difficult to obtain ideal treatment effects

Chinese patent CN1736906A discloses a method and system for treating cold rolling emulsion wastewater, which uses physical separation, biological treatment and chemical precipitation to remove various pollutants and discharge them after meeting environmental protection requirements. The effluent index is Oil content ≤ 10mg / l, suspended solids SS ≤ 30mg / l, COD ≤ 100mg / l, without advanced treatment, the effluent water cannot be reused as cold rolling production water, and can only be discharged or used as dust suppression water for raw material yards. Strict production water use

At present, the low reuse rate of water and serious waste of water resources are common in the cold rolling industry

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