SU1733389A1 - Method for treatment of oil-containing sewage - Google Patents

Abstract

The invention relates to the treatment of industrial wastewater containing emulsified petroleum products. The purpose of the invention is to increase the degree of purification of wastewater from petroleum products while reducing the consumption of flotation reagent-collector during the treatment of wastewater. A high molecular weight cationic flocculant based on a low molecular weight methacid polyhexamethyleneguanidine in an amount of 2-4 mg / l of water in a mixture with cationic surfactant Katamin AB in the amount of 10-12 wt.%, Calculated on the basis of flocculant, is used as a flotation reagent-gatherer. The invention provides a residual content of oil in water up to 1-5 mg / l at a flow rate of 1-5 mg / l flotation reagent. 1 tab.

Description

The invention deals with the treatment of industrial effluent water containing emulsified oil products, chemical flotation, and more, to find application in the petroleum refining industry and the petrochemical industry, as well as in other enterprises where it is possible for oil products to enter the internal waters.

A known method of purification of oil-containing waste water by flotation method according to which water purification from emulsified organic substances (oil, oil products, vegetable and animal oils, etc.) is carried out by means of free-flow flotation using surface-active substances of caustic flotation reagents thionic type, for example primary amines, polyethylen polyamine, rosin amine acetate

The disadvantages of the anhugo method include the increased flow rate of the flotation reagent as well as the insufficient degree of removal of the oil product from the water.

The aim of the invention is to increase the degree of purification of wastewater from petroleum products while reducing the consumption of flotation reagent-collector.

To effect purification method the waste water from oil is carried out by using a pressureless flotation in a flotation reagent gatherer high molecular weight cationic flocculant based on low molecular weight metatsida - polyhexamethyleneguanidine in an amount of 2-4 mg / l in a mixture of water alkildi- metilbenzilammony chloride CicrCis (AB Catamin ) in the amount of 10-12 wt.% in the calculation of the floc nt.

The cationic high molecular weight flocculant based on a poor molecular weight metacide (polyhexamethylene guanidine), obtained by polycondensation of the latter with epichlorohydrin, is a gelatinous aqueous 30%

VJ with

with so

00

Yu

gel with reduced viscosity after stabilization with orthophosphoric acid of a 5% solution of 0.9-1.0 dl / g, which corresponds to a molecular weight of about 100 thousand.

The quaternary ammonium salt of KATAMIN AB is obtained by the interaction of alkyl dimethylamine and benzyl chloride. It is a clear liquid from a colorless yellow color, soluble in benzene, carbon tetrachloride, white spirit. Molecular weight 346-376.

According to the proposed method, the purification of water containing dispersed petroleum product is carried out by the method of shut-off flotation with air. A volumetric air flow rate of 14 l / h per 200 ml of wastewater. The flotation process is carried out in a 300 ml cell made of glass. Before the start of water purification, high-molecular flocculant in the amount of 2-4 mg / l is used in the calculation of the initial water mixed with surfactant Katamin AB in the amount of 10-12 wt.% Calculated on the flocculant. Before and after cleaning the wastewater the water in it determines the residual content of petroleum products.

The quantitative limits of using high molecular weight flocculant as a flotation reagent-collector are determined by that. when it is introduced into wastewater less than 2 mg / l, there is practically no purification of water from the oil product, and when flocculus is added above 4 mg / l, the degree of water purification decreases.

The quantitative limits of the use of the activator reagent are determined by the fact that when adding it to the reagent less than 10 May%, the effect of improving the degree of water purification is not observed, and when introducing the activator reagent over 12% by weight, there is no additional increase in the degree of water purification or it even decreases .

Example. The treatment of waste water containing dispersed oil products in the amount of 500 mg / l is carried out with

-

using flotation reagent-collector by the method of free-flow flotation in a laboratory installation, which is a glass cylinder with a diameter of 50 mm and

5 with a volume of 300 ml. A Schott filter is mounted into the cylinder from below to ensure the dispersion of the air flow. The air flow rate was 14 l / h per 200 ml of wastewater. Duration of flotation

10 cleanup was 10 mi. " Before and after carrying out water purification, it determines the residual content of petroleum products.

Examples with specific additives in the purified water flotation agent-gatherer and

15 flotation reagent-activatra are shown in the table.

The results of the experiments showed that in examples 4, 18-26, 28-31 the degree of purification of oily waste water was

20 higher and the flotation reagent-collector consumption is lower compared to the known method (volumetric air flow rate of 7.2 l / h, cleaning time 20 min).

Thus, the use of the proposed method of purification of oily wastewater by flotation provides an increase in the degree of purification of waste water from petroleum products while reducing the consumption of flotation agent-gatherer.

Claims (1)

Claims The method of purification of oily wastewater, including non-pressure flotation using flotation collectors, followed by mechanical removal of released petroleum products from the surface of the water, characterized in that. In order to increase the degree of wastewater purification from petroleum products while reducing the flow rate of the flotation reagent-collector, a high molecular weight cationic flocculant based on polyhexamethyleneguanidine in the amount of 2-4 mg / liter of water is used as the flotation reagent-collector and additionally alkylbenzyldimethylammonium chloride is added (Cm) -Cis) in the amount of 10-12 wt.% Per floc nt. 25 thirty 35 40 Example Table continuation