SU710977A1 - Method of extractional purification of waste water - Google Patents

Description

one

The invention relates to the treatment of wastewater and can be used in the engineering, chemical and petrochemical industries.

A known method of purification of wastewater from organic substances by coagulants 1.

Closest to the described invention, there is an extraction method for purifying wastewater from petroleum products with aliphatic hydrocarbons, which includes mixing the extractant with wastewater and subsequent emulsion separation of the extractant waste water in C2D gravity clarifiers.

The lack of known methods is low degree of purification. The amount of emulsified oil products in purified water is 5-9 mg / l and mechanical impurities 60-140 mg / l.

The purpose of the invention is. increase the degree of purification.

The goal is achieved by the fact that during phase separation, water saturated with air at a pressure of 5-7 atm is fed by throttling into the sedimentation zone of the gravity clarifier.

volume of 10-14 times less relative purified water.

To carry out the process, the wastewater is mixed with the extractant, put into a gravity settling tank, and then the saturated air under pressure is throttled into the settling zone of the settling tank. As a result of this reception, small air bubbles are formed in the lower part of the settling zone, which carry up the extractant droplets and particles of mechanical impurities moistened with the extractant.

Example: Refinery wastewater with an oil content of 154.4 mg / L and mechanical impurities 97.7 mg / L is mixed with aliphatic hydrocarbons in a 3: 1 ratio in a static mixer. The resulting emulsion is sent to a packed gravity settler with a capacity of 100 MV4ac. Through a throttling device, water that is saturated with air under pressure of 6 atm is flowed through a throttling device into the settling zone of the sump; 12 Through the slotted channel in the upper part of the settling tank

the spent extractant is sent to regeneration, and the treated wastewater is sent to biological treatment or reuse.

After extraction treatment in accordance with the example given, the content of emulsified petroleum products in purified water is 0.13 mg / l and mechanical impurities 14.7 mg / l.

The described method has a high degree of purification and the ability to reuse part of the treated wastewater.

Claims (2)

1. Proskurkov V.A., Schmidt L.I. Wastewater treatment in the chemical industry. L., Himi, 1977, p.381. 2. USSR author's certificate №451640, cl. C 02 C 5/02, 1972.