SU1381077A1 - Method of biochemical treatment of effluents of primary wool processing mills - Google Patents

Abstract

This invention relates to the biological treatment of concentrated wastewater. The aim of the invention is to improve the degree of wastewater treatment and improve the sedimentation properties of activated sludge. The method includes anaerobic oxidation in methane tanks, sedimentation and aerobic oxidation. Before settling, the sludge mixture is saturated with an ozone-air mixture at a ratio of oxygen and ozone (12-15): 1 and a dose of ozone of 0.1-10 mg / l sludge mixture, and the sediment after settling is sent to the digester at a rate of 0.3-1.5 wastewater feed rates for treatment. The method allows a 29% increase in the degree of purification (as compared with the prototype), the sludge index is 300-330 (versus 405 according to the prototype). 4 tab. (L

Description

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This invention relates to the biological purification of concentrated water.

The purpose of the invention is the further purification of wastewater and the improvement of the sedimentation properties of the active

silt

The method is carried out as follows. Concentrated wastewater from the wool pretreatment plants is supplied to the methane tank at a certain rate. Here, as a result of biochemical processes, the oxidation of organic compounds and the formation of gas occur with the help of anaerobic sludge. The sludge mixture from the digester is fed to a contact chamber, into which the ozone-air mixture with a given ratio of oxygen to ozone is injected. The amount of ozone-air mixture is introduced at a rate that provides a dose of ozone from 0.1 to 10 mg / l sludge mixture. After the contact chamber, the sludge mixture is fed to settling, then to the aeration tank.

The treatment of anaerobic sludge with an ozone-air mixture allows partial destruction of extracellular polymers, making the bacterial cell capable of flocculation and more intensive precipitation, to the bottom of the settling tank, i.e. improve its sedimentation properties. As a result of more intensive settling of anaerobic sludge in purified water, less suspended solids are contained and the load on the subsequent purification stage is reduced. Ozone, as a strong oxidizing agent, can not only create the best conditions for the release of activated sludge into the sediment, but also eliminate the formation of metabolites, isolate them in the sump from sludge water both by direct oxidation and by the combined oxidation process. . As a result of the contact of the sludge mixture with ozone, the residual concentration of organic compounds and the products of the metabolism of the anaerobic bacterial cell decreases. This makes it possible to reduce the duration of the lag phase of aerobic bacteria development in the aerofeat, make aerobic or active already at the beginning of aeration and thereby intensify the wastewater treatment process and increase the cTi iuMib of wastewater treatment in aeroten; 1. But with respect to the bacterial cell of anaerobic activated sludge, ozone has a direct effect on the cell capsule, on the cell membrane and cytoplasmic membrane. High concentrations of ozone can destroy the cell membrane and membrane, lead to cell death, low only affect the cell capsule and capsular polymer, separate the phospholation process and the formation of adenosine triphosphate at the substrate level. Such conditions contribute to the preservation of bacterial cells, however, sharply reduce the physiological activity of the cell, the ability to process the substrate and form a gas. In these conditions, settling of anaerobic sludge as long as possible without disrupting the process with fermentation gas. 0 standing anaerobic sludge is returned from the septic tank to the methane tank at a certain rate. The return of sludge at a certain rate ensures the preservation of a high concentration of anaerobic bacteria in the digester and a high load on the structures. In this case, the ability of the metamtenka in terms of the rate of oxidation of organic compounds, in the rate of flow of wastewater increases. 3TONry also contributes to the treatment of recycled activated sludge with ozone. Its peculiarity lies in the fact that anaerobic bacterial cells are subjected to short-term exposure, with a definite strength — a dose of ozone of 0.1–10 mg / l, after a determined and constant period of time, associated with the rate of recirculation. Short-term, cyclic treatment of a bacterial cell with ozone is not capable of destroying it, but is capable of transferring it after a certain period of time, to a higher level of physiological activity. It is achieved by the partial oxidation of mucopol saccharides of the capsular polymer cell and also the metabolic products of the cell returned to the methantank. Oxidation allows the capsule layer to be reduced and the organic matter of the substrate to be made more accessible to oxidation. The dose of ozone to the metabolites reduces the level of inhibition by the type of feedback and allows, upon completion of this process, which also needs time, to increase the activity

enzymes capable of oxidizing organic wastewater compounds. This contributes not only to the creation of favorable conditions for the further aerobic treatment of wastewater (silt water contains a minimum amount of suspended matter; organic matter and their anaerobic decomposition products are partially oxidized by the chemical IM method), but also provides intensive anaerobic purification of concentrated wastewater in the digester.

Example. Wastewater from factories of primary processing of wool with an initial content of organic compounds in g / l is fed to the methane tank at a rate of 0.15 days. The fermentation temperature is maintained at ypoB not 33 C. The sludge mixture is removed from the methane tank to the contact chamber. Here, the water is saturated with an ozone-air mixture from an ozonizer for 30 minutes. The ratio of oxygen and ozone in the ozone-air mixture varies within 10-20 hours of oxygen to one part of the ozone. After contact with the ozone-air mixture, the sludge water is sent to a sump. The sludge water freed from suspended substances of anaerobic sludge is diverted to the subsequent purification stage, to the aerotank, and the anaerobic sludge dropped to the bottom of the settling tank is returned to the methane tank. Speed

the return of sludge varies from 0.1 to 2.0 feed rates for cleaning.

In tab. Table 1 shows the effect of the composition of the ozone-air mixture on the degree of wastewater treatment, Table 2; Table 2 shows the effect of the ozone dose on the degree of wastewater treatment. 3 - the effect of the recycling of anaerobic sludge on the degree of purification.

In tab. A comparative results for the treatment of concentrated wastewater. By a known method, the sludge index is 405 cm / g of activated sludge.

Claims (1)

Invention Formula The method of biochemical wastewater treatment of plants for the primary processing of wool, including anaerobic oxidation in the digester, sedimentation and aerobic oxidation, is different because, in order to increase the degree of purification and improve sedimentary properties of activated sludge, before settling, the sludge mixture is saturated with an ozone-air mixture when the ratio of oxygen and ozone is 12–15: 1 and the dose of ozone is 0.1–10.0 mg / l of sludge mixture, and the sediment after settling is fed to the methane tank at a rate of 0.3–1.5 of the feed rate of the initial wastewater. Table 1 2i8 2.8 2; 75 2.75 2.7 2.75 2.9 0.0 0.0 0.05 0.00 0.05 -0.05 -0,015 3.5 3.2 1.55 1.5 1.45 1.5 2.0 Continued t, bl.1 Specific rate, oxidation, MGHPK / g without e.yl per hour 5.34 Table 3 9.00 69 138107710 Continuing tab, Wastewater Treatment Indicators Cleaning method Famous Feed rate sewage, days Sludge Recirculation Rate Factor The ratio of Oh, the dose of ozone, mg / l Load silt mg COD / g bez.nla in day Oxidizing MODIness of CHPCC per m methane tank per day eatable The increase in the degree of purification and efficiency of the process in the proposed method compared with the known, Z from the known 88 40 2.9 99