RU1787953C - Sewage water fine cleaning apparatus - Google Patents

Abstract

Usage: deep treatment of domestic and industrial wastewater that has undergone mechanical treatment in biological treatment facilities, followed by filtration and ozonation. SUMMARY OF THE INVENTION: The ozone reactor is the final structure in a sequential flow diagram, is made counter-current, and is equipped with a water trap and a sealed domed ceiling connected by a vacuum ozone conduit to an ejector mounted on a pressure duct. The technical air pipeline through the air treatment unit is introduced into the ozone generator. The biooxidant is equipped with a vertical column installed with the formation of a bottom gap. The column is made of the upper conical part with a working nozzle attached to the pressure sludge returning activated sludge, and an umbrella trap placed above the pneumatic aerators and immersed in the sludge environment of the biooxidant with the formation of a hydraulic seal. 1 s.p. file, 1 ill. (/ WITH

Description

The invention relates to the field of deep purification of domestic and industrial wastewater that has undergone mechanical treatment in biological treatment facilities, followed by filtration. At the same time, taking into account the universal effect of ozone on pollution, its advantages as a powerful and fast-acting oxidizing agent, oxygen supplier and effective disinfectant, it is recommended to use ozonation as a method of cleaning and disinfecting. Ozone can be used to discolor effluents, remove suspended solids and colloids, oxidize complex organo-mineral complexes, toxic ions, organic microcontaminants, and as a disinfectant.

A known installation for deep cleaning. mechanical wastewater treatment plants comprising physicochemical treatment facilities, reagent facilities, as well as an ozone reactor, an air preparation unit, and an ozone generator. Factors that reduce the efficiency of such an installation are the need for reagents, a significant amount of precipitation formed in this process, an increase in the level of salinity of water, which impairs its quality and causes an additional consumption of ozone.

Also known is a device for the deep cleaning of wastewater that has been mechanically cleaned, including a biooxidant with pneumatic aerators connected to an N air blower

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a porn air duct, a secondary settling tank with a circulation pump equipped with opening and pressure pipes for returning activated sludge, a micro drum mesh filter, an ozone reactor with an ozone generator in communication with the air preparation unit, and a quick filter connected in series. Factors limiting the effectiveness of this installation are the additional consumption of ozone, a valuable technical product, caused by the presence of organic suspension carried out after the secondary settling tank, the almost complete absence of dissolved oxygen in the purified water after the quick filter, as well as the periodic swelling of activated sludge caused by the presence in water of a number of industrial pollution, low concentrations of dissolved oxygen in the biooxidant, pH fluctuations of wastewater and high loads and activated sludge.

The aim of the invention is to provide deep purification and disinfection of water while reducing capital and operating costs,

This goal is achieved by the fact that in the installation for the deep cleaning of wastewater that has been mechanically cleaned, including a bio-oxidizer with pneumatic aerators connected to an air blower by a pressure air duct, a secondary sump with a circulation pump equipped with a suction and pressure sludge returning activated sludge, and a micro-mesh drum a filter, an ozone reactor with an ozone generator in communication with the air preparation unit, and a fast filter connected in a serial circuit, fast fil It is connected by a filtered water pipeline to an ozone reactor, which is the final structure in a serial circuit, while the ozone reactor is countercurrent and equipped with a water seal and a hermetic domed ceiling connected to an ejector mounted on a pressure air duct, a vacuum water piping, and a pressure air duct connected to the technical air pipeline introduced through the air treatment unit into the ozone generator.

It is advisable that the biooxidant be equipped with a vertical column installed with the formation of a bottom slit having an upper and lower conical part and a central cylindrical part, with a working nozzle with a return sludge returning activated sludge connected to it and an umbrella trap connected by means of a pipeline of ozone-oxygen mixture with the upper conical part of the column placed above pneumatic aerators and immersed in a silt medium of a biooxidant with a sample by opening the water trap, and the technical oxygen pipeline is additionally introduced into the air treatment unit.

The drawing shows a flow chart of the proposed installation for deep wastewater treatment.

A deep wastewater treatment plant includes: a biooxidant 1 with a mechanical wastewater pipe 2 and pneumatic aerators 3 connected by a pressure duct 4 to an air blower 5 equipped with a mechanical filter 6 for preliminary dust removal; secondary sludge 7, connected to the bio-oxidizer by a sludge mixture pipe 8, with a circulation pump 9, equipped with a suction sludge return line 10 connected to the sludge medium pipe 11 to supply an additional amount of working medium from the bio-oxidizer with a lack of return sludge flow rate, and a pressure sludge line 12 return activated sludge; a micro drum mesh filter 13 connected to the secondary sump by a biological wastewater pipe 14 and a pre-filtered water pipe 15 to a quick filter 16; an ozone reactor 17 connected to the quick filter by a filtered water pipe 18 and equipped with a water trap 19, a hermetic domed ceiling 20 connected to an ejector 21 mounted on a pressure duct, a vacuum ozone conduit 22, an ozone disperser 23 connected via a pressure ozone conduit 24 to an ozone generator 25, communicated in turn by the air conditioning pipe 26 with the air conditioning unit 27 with the technical oxygen pipe 28 and the technical pipe 29 introduced into it air attached to the air blower, as well as the pipe 30 deeply purified liquid; a vertical column 31 installed in the biooxidant with the formation of a bottom slit 32, having an upper conical part 33, a lower conical part 34 and a central cylindrical part 35, with a working nozzle located in the upper part

36, with a pressure sludge returning activated sludge attached to it, and an ozone-oxygen mixture conduit 37, attached to a trap umbrella 38 mounted above the pneumatic aerators, and immersed in the silt medium of the biooxidant to form a water trap 39; stop valves 40.

Installation for deep wastewater treatment works as follows. Mechanical wastewater wastewater, through mechanical wastewater pipe 2, enters the biooxidant 1, where compressed air in the form of small bubbles is supplied from the air blower 5 through the pressure air duct 4 through pneumatic aerators 3 During the air sparging of the working layer of sludge medium into of biooxidant 1, mass transfer of oxygen from the gas phase to the liquid is carried out, which provides a process for the biological contamination of organic pollutants with dissolved oxygen. Aerobic microorganisms are the main oxidizing component of activated sludge, which is pumped from the secondary sump 7 by means of a circulation pump 9, first through the suction sludge 10 and then through the pressure sludge 12 of the return activated sludge to biooxidant 1.

A mixture of activated sludge and biologically treated wastewater by gravity pipeline 8 flows by gravity into the secondary sump 7, where, under the influence of gravitational forces, activated sludge is deposited, and the clarified wastewater flows through a biological wastewater pipe 14, which passes to a rotating drum micro-mesh filter thirteen.

On a rotating drum micro-mesh filter 13, wastewater is filtered through a fine-mesh mesh with mesh sizes of 25-100 μm superimposed on a supporting mesh with mesh sizes of 2 x 2 mm, as a result of which activated sludge flakes are removed, as well as small mechanical impurities carried out during periods of fluctuation in the influx of wastewater from the secondary sump. Mechanical impurities are released as a result of both mechanical screening in the mesh web and their retention in the layer of sediment formed on the mesh. The axis of rotation of the drum is the pre-filtered water pipe 15. After processing on a drum micro-mesh

wastewater filter 13 is characterized by BOD values of 10-12 mg / l, suspended matter content of 8-10 mg / l and through a pre-filtered water pipe 15 is directed to the top of the quick filter 16 loaded with granular material with a particle size of 1.5- 3 mm.

As the waste fluid moves through the granular charge of the quick filter 16 from top to bottom, it is filtered, accompanied by the gradual removal of suspended and colloidal particles as a result of their adhering to the grains of the charge. So

In this way, at least a 50% reduction in the concentration of impurities entering the fast filter is ensured, as a result of which the past fast filter wastewater is characterized by the values

BODfull. 6-9 mg / l with a suspended matter content of 4-5 mg / l.

After processing on the quick filter 16, the wastewater flows through the filtered water pipe 18 to the upper

part of the counter-current ozone reactor 17, in the lower part of which an ozone disperser 23 is installed, by means of a pressure ozone line 24 connected to an ozone generator 25. Separation from the surface

of ozone dispersant 23, the bubbles of the ozone-air mixture rise up, as a result of which the ozone passes into the aqueous solution, entering into oxidative reactions. As a result, the residual

difficultly oxidized organic pollutants with BOD complete. purified liquid up to 3-4 mg / l, as well as its deep disinfection as a result of the destruction of pathogenic bacteria. Cleared

sewage from the gas trap 19 of the ozone reactor 17 is discharged outside the installation through a pipeline 30 of deeply purified liquid and can be discharged into its sanitary-chemical indicators

water body of the highest category of water use or is directed to reuse in the technical water supply system. The main raw material for producing ozone is atmospheric air. Preliminary dedusting of air is carried out on a mechanical filter 6 when it enters the air blower 5. The air is supplied to the ozone generator 25 from the air blower 5 by

the technical air pipe 29 connected to the air preparation unit 27, where excess moisture is removed, artificially cooling the air to a temperature of + 5- + 7 ° C, and also dried to a moisture content of 0.05 g / m3 by adsorption on

aluminum gel or silica gel loading. An industrial method for producing ozone is based on the partial splitting of air oxygen molecules into atoms by the action of a quiet electric discharge, followed by their attachment to undigested oxygen molecules. The synthesis of ozone and the formation of an ozone-air mixture with an ozone concentration of 10-20 g / m3 occurs in an electric ozone generator 25 (ozonizer) operating under excess pressure of the gaseous medium.

Ozone has a higher redox potential, and, therefore, a higher bactericidal and oxidative effect than, for example, active chlorine. The use of ozone along with water disinfection eliminates residual concentrations of difficultly oxidized pollutants such as petroleum products, phenols, cyanides, sulfides, detergents, etc. from the wastewater; during oxidation, the formation and accumulation of degradation products occur, which differ from the starting compounds not only in chemical structure, but also in toxicity. The maximum permissible concentration of ozone in the working rooms is 0.0001 g / m3, in connection with which the working rooms of the ozonation station are equipped with powerful ventilation units, and it is also necessary to constantly monitor the tightness of process pipelines and equipment.

In addition, the degree of use of ozone in the counterflow reactor does not exceed 0.85-0.9 of its initial amount, i.e. 10-15% of this relatively expensive gas is not only not used in the process, but also poses a real threat to air pollution.

The solution to this problem is achieved by the fact that the ozone reactor 17 is equipped with a water trap 19, as well as a hermetic domed shutoff 20, by means of a vacuum ozone conduit 22 connected to an ejector 21 mounted on the pressure duct 4, Ozone, not consumed during the oxidation reaction, together with gaseous oxidation products , passing through the working fluid layer of the ozone reactor 17, is collected under a sealed domed ceiling 20, from under which the ozone-containing mixture under the action of the pressure created by the ejector 21, flows into the pressure duct 4 and together with compressed atmospheric air enters the biooxidant 1.

In biooxidant 1 along with the use of atmospheric oxygen, biological residual ozone is absorbed by microorganisms of activated sludge. The enzymes secreted by them decompose organic contaminants according to the scheme of multistage enzymatic and chemical reactions, and the oxidation process is conjugate when the stages of biological and physicochemical oxidation alternate. Under the influence of physicochemical factors, such as k ozone, on the intermediate and final decay products, favorable conditions are created for the formation of free radicals, which speeds up the wastewater treatment process by 1.3-1.5 times and significantly reduces the working volume of biooxidant. This allows practically

completely avoid unproductive losses of ozone into the atmosphere.

In addition, significantly complicates the operation of biological

swelling of activated sludge, consisting in the deterioration of its sedimentation properties, an increase in the sludge index. The factors causing the deterioration of the sedimentation properties of the activated sludge biocenosis are the low density of cotton and the branching of its peripheral structures, caused by excessive accumulation or changes in the composition of extracellular polysaccharides that fix heterotrophic microorganisms to google; mass development of filamentous microorganisms. Various methods are used to combat swelling of activated sludge, mechanical or chemical effects on sludge, changes in process conditions and others, the most promising application of oxidizing agents acting directly on polysaccharides, zooglides and filamentous microorganisms. A highly active oxidizing agent that can be obtained directly at the point of use is ozone. By treating activated sludge with it, one can achieve an intensification of the biological treatment process due, in particular, to a decrease in the sludge index. The decrease as a result of ozonation of the sludge index (with periodic supply of ozone with a dose of 5.0-6.0 Omg / g day) in a wide

the load range allows biological wastewater treatment under increased loads on activated sludge, which is impossible under normal conditions due to swelling of activated sludge and disruption of operating conditions.

In addition, the use of small doses of ozone in biological treatment processes contributes to a deeper removal of ammonia nitrogen and the almost complete elimination of unpleasant odors.

When technical oxygen is used as a raw material for ozone production, as an additive or as an alternative to atmospheric air, the productivity of an ozone generator increases by 1.7-1.9 times, while at the same time reducing by 1.5-2 times the specific energy consumption. This is achieved by additionally introducing technical oxygen into the air preparation unit 27. In addition to a significant increase in the concentration of ozone in the ozone-air mixture leaving the ozone generator 25, the concentration of oxygen entering the biooxidant 1 through the vacuum ozone line 22 also increases. From the point of view of the rate of biological oxidation, an increase in the concentration of oxygen in the gas mixture introduced into the biooxidant has an additional effect to increase the speed of the biological process. However, not all technical oxygen and ozone have time to dissolve during the passage of the working layer of the sludge medium, which leads to an economically undesirable loss of a valuable gas mixture into the atmosphere.

To avoid this, it is advisable to install a trap umbrella 38 in the bio-oxidizer above the pneumatic aerators 3, the edges of which are immersed in the silica environment of the bio-oxidizer to form a gas trap 39. The gas mixture with a high content of technical oxygen coming out of the bio-oxidizer is collected by a trap umbrella 38, from where through the pipe 37 the ozone-oxygen mixture is aspirated into the upper conical part 33 of the vertical column 31, into which the rarefaction working nozzle 36 is connected to the pressure discharge pipe 12 of the return activated sludge. Entrained in a downward flow of recirculated activated sludge, ozone-oxygen mixture bubbles, the passage of the middle central cylindrical part 35 of the vertical column 31, fall into the lower conical part 34 of the vertical column. When a certain section of the lower conical part 34 of the vertical column 31 is reached, the downward flow velocity of the return activated sludge and the rate of cramped ascent of ozone-oxygen bubbles become equal, as a result of which the gas bubbles soar at a constant height until they are almost completely dissolved. Return sludge flow,

saturated with dissolved oxygen, is under the catalytic influence of ozone, and containing small bubbles of sparingly soluble residues, through the bottom slit 32 enters biooxidant 1, bringing with it active microorganisms that carry out biological oxidation of pollution.

Thus, this invention

0 provides deep purification and disinfection of wastewater using biological treatment with active sludge, filtration and ozone oxidation according to a technology that involves practically

5 full use of ozone and technical oxygen, which reduces energy consumption by 1.7-1.9 times, and also provides a reduction in the volume of aerobic biooxidant by 1.3-1.5 times. Added benefit

0 of the present invention is to improve the quality of the air as a result of eliminating ozone leaks when using a vacuum system for transporting it to a place of reuse, eliminating unpleasant odors during biological wastewater treatment. The use of ozone to improve the sedimentation properties of swollen activated sludge can improve the stability of biological treatment plants, as well as ensure the quality of treatment at the level of modern environmental requirements

The aforementioned technological features make it possible to increase the productivity of the ozone generator while at the same time reducing the specific energy consumption by 1.5–2 times, and also reduce capital costs by reducing the amount of biooxidants by 1.3–1.5 times.

Claims (2)

SUMMARY OF THE INVENTION 1. A wastewater deep purification plant comprising a biooxidant with pneumatic aerators connected to an air blower by a pressure air duct, a secondary sump with a circulation pump, with suction and pressure sludge of a return activated sludge, and a micro-mesh drum 0 filter, ozone reactor with ozone generator, air treatment unit and quick filter, connected in series, characterized in that, in order to ensure deep cleaning and disinfection of water while reducing capital and operating costs, the quick filter is equipped with a filtered water pipeline, connecting it to an ozone reactor, which is installed at the end of the serial installation scheme, the ozone reactor is counter-current and equipped with a water trap and a sealed domed ceiling with a pressure duct and an ejector installed on it, a vacuum ozone conduit, while the pressure duct is equipped with a technical air pipe connected to it and introduced into the ozone generator through an air preparation unit. 2. The installation according to claim 1, with the fact that the biooxidant is equipped with a vertical column installed with the formation of a bottom gap and made of upper and lower conical parts and price the trailing cylindrical part, with a working nozzle located in its upper conical part, attached to the pressure flow pipe of the return activated sludge, and an umbrella trap with an ozone-oxidizing mixture pipeline connected to the upper conical part of the vertical column, while the umbrella trap is placed above the pneumatic aerators and immersed biooxidant into the silt medium with the formation of a water trap, and the air treatment unit is additionally equipped with a technical oxygen pipeline.