SU1611877A1 - Method of treating fat-containing waste water - Google Patents

Abstract

The invention relates to methods for treating wastewater containing fat, and can be used in fishing and processing plants. The aim of the invention is to increase the degree of purification of grease wastewater from fish processing industries and simplify the process. To do this, on the inner surface of vertically installed tubes of porous lipophilic material for 1-1.5 hours with a gradual increase in pressure from 0.2 to 0.5 MPa, a water-insoluble fatty layer is formed that prevents the passage of fatty particles by pre-circulation of wastewater in a closed circuit, and then the wastewater is filtered for purification. Graphite, ceramics or polymers are used as porous lipophilic material. With an increase in the circulating water concentration of fat particles 2 times it is diverted to the separation. The method provides the residual content of fatty particles in the purified water before the MPC is discharged into the city sewage system (50 mg / l) and allows an increase in the degree of purification up to 98% compared to 78% in the known method. 1 hp ff, 3 tab.

Description

The invention relates to methods for the treatment of wastewater (CB) containing fish oil, and can be used in fishing and processing plants.

The purpose of the invention is to increase the ste. penalties for cleaning zabirenny SV fish processing industries and simplify the cleaning process.

For carrying out the process CB, with: holding fish fat in an amount up to 3.0 g / l, is passed through the tubes

. Of porous polymeric or inorganic (graphite, ceramic) materials with a gradual increase in pressure from 0.2 to 0.5 KPa. As a result of the sorption of dispersed fat particles, a dynamic layer is formed that prevents the passage of fish oil particles into the filtrate. With an increase in the thickness of the sediment layer, the force of adhesion of the particles to each other decreases, and the upper fat particles are washed away from the accumulated layer due to the tangential flow of the separable mixture, which allows an increase in the filtration cycle time. The tubes are installed vertically, the flow of the liquid to be purified is carried out from the bottom up and the enlarged fat drops are carried away.

 vl

Those with a flow, in contrast to the known method, where the liquid to be purified is forced through a septum of porous lipophilic material.

The degree of sticking of oils and fats of different nature varies. As a rule, vegetable and animal fats are retained on the surface more firmly than mineral oils (oil). This is explained by the different content of natural surfactants in their composition, which increase the adsorption effect.

During the period of the production of the dynamic water-insoluble layer, the filtrate, together with the circulating CB, is discharged into the tank.

After 1-1.5 h of the circulation of CBs along a closed circuit, the filtrate begins to be drained into the municipal sewage system. In circulating drains, the content of fatty substances gradually increases with an increase in the fat concentration by a factor of 2 (as compared with the initial CB), the purified liquid is fed to the separator in order to extract the fatty product.

To restore the performance of the filters, they are periodically washed. Detergent containing alkali, alkaline salts (ML-51, Labomid) is pumped through filter cartridges from porous tubes for 30 minutes.

Example 1. Polymer tubes of grade 5018-8 and 5013-7 are fed a grinded core with a content of 2360.0 mg / substances extracted by chloroform. The formation time of the working, water-soluble, fatty, gel layer is 1-1.5 hours. The effect of the formation of the bulk layer on the residual content of fatty substances in the filtrate is presented in Table. one.

From the data obtained, it follows that when a gel layer is formed within 1-1.5 hours, the residual fat concentration in the filtrate decreases to a CCS discharge into the municipal sewage system (50 mg / l). The time of formation of the gel layer with a gradual increase in pressure from 0.2 to 0.5 MPa. Also determined for the filter 5018-8. The results are presented in Table. 2

The working layer is produced with a gradual increase in pressure from 0.2 to 0.5 MPa. In this case, a dynamic layer is formed on

Q 5

0

five

inner surface of the porous tube. Increasing pressure allows the upper layers of fatty substances to be flushed away, which leads to less clogging of the pores, a slow decrease in productivity and an increase in the volume of filtrate per filter cycle.

The dependence of filter performance (G, l / m.h) on time at various pressures is presented in Table. 3

And p. 2. Meter 2. A grilled NE containing 3000 mg / l of substances extracted with snoroform with a COD of 9000 mg Od / l is cleaned on hollow graphite tubes. The time between the gel layer is 1.5 hours and the pressure gradually increases from 0, 2 to 0.5 MPa. The residual concentrations of the substance extracted with chloroform and COD in the filtrate are 36.0 and 358.0 mg / l, respectively, which corresponds to the concentrations allowable for discharge into the city sewer.

The advantage of the proposed method is the simplicity of instrumentation and operation with increasing the degree of purification of CB from fish oil to 98% compared with 78% by a known method, as well as the possibility of using fat in production. An increase in the duration of the interregenerative period is achieved by intermediate extraction of fat (with an increase in its concentration in the HB by a factor of 2) by the method of gravity separation.

Claims (2)

1. The method of purification of fat-containing wastewater, including filtration through a porous lipophilic material with a water-insoluble fatty layer, which means that, in order to increase the degree of purification of wastewater of fish processing industries and simplify the process, filtering is carried out through vertically installed tubes of porous lipophilic material — graphite, ceramics, or polymers, and a water-insoluble layer is formed on the inner surface of the tubes by circulating the sewage through a closed loop within 1.0-1.5 hours with a gradual increase in pressure from 0.2 to 0.5 MPa. 51611877; 6 2. The method according to claim 1, of the distinguishing particles 2 times as compared with u and with the fact that the circulating primary material is withdrawn for separation, when increasing the concentration of fat.