SU929594A1 - Method for biologically purifying effluents - Google Patents

Description

(54) METHOD OF BIOLOGICAL WASTEWATER TREATMENT

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The invention relates to methods for the biological treatment of wastewater, in particular to the biological treatment of wastewater with activated sludge.

There is a method of improving the sedimentation properties of activated sludge by introducing lime into the wastewater before the aeration tank 11.

The disadvantages of this method include a high dose of reagent, high pH, an increase in the salinity of fine water. For example, according to the method, the dose of the reagent is 15O4OO mg / l. In addition, when using lime, there are a number of difficulties associated with the formation of carbonate deposits on the walls by the communication of sewage treatment plants. The carbonate deposits are caused by aeration and the release of carbon dioxide by microorganisms in the aeration tank, resulting in the formation of calcium carbonate.

There is a method according to which a hundred "blyuyu water before it enters

iron and aniomini salts are introduced into the aeration tank separately, in combination with each other, lime and 2.

The disadvantages of this method are also a high dose of reagents, an increase in the salinity of the purified water, and a large volume of difficult-to-compacted sludge.

The closest in technical essence is a method of biological

10 of wastewater treatment, inclusions, treatment of the latter with active sludge (mixing and aeration of the sludge mixture), followed by settling and section 1 of the liquid and solid phases, and before settling, the mixture is treated with an electric field (g).

The purpose of the invention is to increase the degree of purification and improve the sedimentation properties of actigo silt.

20

In order to achieve the goal, wastewater is subjected to electrotreatment at the current density O, 1-O, 8 A / pm and the amount of procuminal electricity of 20-120 A.C. before mixing with activated sludge. not 1 m of water.

As a result of pre-electrocoagulation, not dissolving complexes of iron or aluminum occurs, which bind organic matter on themselves and when mixed with active sludge in the aeration tank, they contribute to better microbial assimilation. This improves the sedimentation properties of the activated sludge: the sludge mixture is easily separated, and the excess activated sludge is well compacted and dehydrated.

At the same time, the removal of heavy metals from phosphorus compounds and toxic for biological treatment of waste metals from wastewater occurs.

Example. Wastewater from a dairy plant with BOD, ds1020 mg / l, 918 ml / l and 83O is electrocoagulated in a laboratory electrolyzer with soluble iron electrodes with the following pairs, etra: current density 0.2 A / dm, amount of skipped electricity 32.5 A.ch. on

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1m of water. Then these waters are mixed with activated sludge and aerated for 18 hours. After completion of aeration, the sludge mixture is separated in the cylinder. The settling time is 9 O min.

The results of the test method are given in table. 1, and the comparative data of the proposed and known methods in table. 2

Thus, the use of the invention makes it possible to reduce the sludge index by 1.34-1.48 times, and the residual concentration of phosphorus in the purified water to decrease by 1.52 to 25 times.

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substances compared to

in a known way.

At the same time, when applying the proposed method, the cost of electric power for electrocoagulation is significantly reduced, the required volumes of electrocauporeors decrease (by 6–80%),

the reliability of their work is increased, since no sludge sticks to the electrodes.

Tablipa 1

P1yudozhenie tab. one

Claims (1)

Claim The method of biological wastewater treatment, including mixing wastewater with activated sludge, aeration of the sludge mixture and its subsequent separation, and electric treatment, distinguished by the fact that, in order to increase the degree of purification and improve the sedimentation properties of activated sludge, wastewater before mixing activated sludge is subjected to electrical treatment at a current density of 0.1-0.8 A /. pm ² and the amount of flow electricity 20-120 A.h, per 1 kP of water.