RU1853U1 - Dairy Biological Wastewater Treatment Station - Google Patents

Abstract

STATION FOR BIOLOGICAL TREATMENT OF WASTE WATER OF A MILK FACTORY, containing a device for supplying water for cleaning, a receiving chamber of a pumping station with a grate, a sand trap, a pipeline for supplying water for biological treatment, a bioreactor made in the form of a body with a bottom, with a drainage tray for purified water, a pipeline for removing excess activated sludge and an airlift for pumping the sludge mixture, a post-treatment unit and sludge platforms, characterized in that the station is equipped with a mixing chamber for waste water with a sludge mixture, made in the form of a funnel, equipped in the lower part with a pipeline for removing an air-saturated sludge mixture, the bioreactor is equipped with a built-in chamber for the sludge mixture, made in the form of a funnel, inside of which an airlift is located, the outlet of which is located in the mixing chamber of waste water and sludge mixture, a mixing device located along the periphery of the sludge mixture chamber and at the level of its upper edge, and a pipeline for removing purified water for post-treatment, connected to a drainage tray purified water, bottom to The bioreactor shell is made conical or pyramidal, the excess activated sludge discharge pipeline is made in the form of a siphon, the water supply pipeline for biological treatment is connected to the mixing chamber of waste water with the sludge mixture, and the discharge pipeline of the air-saturated sludge mixture is connected to the conical or pyramidal bottom of the bioreactor, post-treatment unit consists of a chamber for mixing purified waste water with reagents and a cylindrical-conical clarifier equipped in the upper part with a thin-layer sedimentation block and a collection tray of clarified water connected to the clarified water pipeline, and in the lower part

Description

 P,

fp

MKI 002 F 3/12

Biological wastewater treatment plant of the dairy.

The invention relates to the field of wastewater treatment, containing emulsified fats, dissolved and colloidal organic pollutants, suspended, carbon and nitrogenous substances and can be used for the treatment of highly concentrated wastewater of food industry enterprises (meat plants, dairy farms, fish factories).

Production wastewater from dairy plants is typically water from flushing process equipment and milk containers. These wastewaters are contaminated with losses of milk and dairy products, production wastes, reagents used when washing equipment and impurities washed off the surfaces of containers, floors, vehicles, etc. All waste is a valuable nutritious product and can be used for fattening young animals or as additives in the feed ration of livestock.

The wastewater of these plants is highly concentrated in terms of the content of organic pollutants and requires efficient and environmentally friendly technologies for cleaning, as well as combined compact plants, which can significantly reduce the area allocated to treatment plants and increase the degree of purification of accurate .abd from both suspended, colloidal and organic pollution, and from nitrogenous substances.

and apply. The most widespread technology is the use of activated sludge, alternately subjected to the influence of aerobic and anaerobic conditions.

Known designs of bioreactors, which are compact combined installations in which the functional processes of biological wastewater treatment and clarification of purified water. The most important element is the unit for returning activated sludge from the settling zone to the aeration zone. The activated sludge of dairy enterprises is light, slowly settling, and therefore requires very fine organization of fluid flows and does not tolerate sharp fluctuations in the flow rate and composition of wastewater.

It is known equipment in which the separation of activated sludge and its return to the process using airlifts are used for the treatment of highly concentrated wastewater, while the aeration period of the mixture of wastewater and activated sludge is extended and the duration of sludge regeneration is increased, which contributes to a more complete oxidation of fatty and organic substances. / USSR Author's Certificate N 981250, C02F 3/02, 1981 /

The disadvantage of this equipment is the low specific productivity due to the large volumes that are necessary to achieve the age of activated sludge sufficient for nitrification and denitrification processes.

Known equipment for biological / wastewater treatment containing organic and nitrogenous substances. The device can be made monoblock. Moreover, in a cylindrical body representing an aerobic treatment device

In a circular shape with a free surface, there is a vertical cylindrical body representing an anasobic denitrification device and a sludge separation (separation) chamber. / Copyright certificate of the USSR N 1442508, C02F 3/12, 1982 /

The combination of nitrification, separation and denitrification zones in one building allows to reduce the area occupied by the construction, but their size is still significant, and the degree of water purification is not high enough. In addition, the use of pneumatic aeration for the treatment of highly concentrated wastewater does not provide the introduction of a sufficient amount of oxygen due to the limited capabilities of the aerators.

Known bioreactor - aeration tank-settler, which is a combined structure made in the form of a housing with devices for supplying water for treatment, drainage of purified water and excess activated sludge, and consisting of two compartments, each of which includes an aeration tank equipped with a pneumatic aerator, and a secondary settler . The sludge mixture is taken from the aeration tank by airlift and fed into the distribution tray of the secondary sump equipped with a triangular weir for measuring the flow of the sludge mixture. Through a gear spillway, the sludge mixture enters the prechamber, in which air bubbles and foam are separated from the liquid, and the formation and formation of activated sludge flakes. This part of the sump is separated by a semi-submersible baffle. Most of the activated sludge is deposited directly at the outlet of the chamber, a smaller part is discharged into the sump itself, where b

deep clarification of purified water is carried out. Active sludge settles in two sumps having openings in the lower part for free access to the aeration tank. The continuous exit of sludge from the pits into the aeration tank is ensured by supplying the sludge mixture with an airlift. Foam and floating particles of sludge are collected by a semi-submerged partition, driven into a tray and then sent through a pipeline to silt sites. Excess activated sludge is taken from the first downstream sludge pit and, under hydrostatic pressure, is discharged to the sludge pads. / Shifrin S.M., Ivanov G.V. et al. Wastewater treatment of meat and dairy industry enterprises. M .: Light and food industry, 1981, p. 189-190 /.

The disadvantages of this bioreactor are the low degree of removal of nitrogenous substances and the use of pneumatic aeration.

Closest to the technical essence of the proposed is a biological sewage treatment plant of the dairy, containing the receiving chamber of the pumping station, grates, sand traps, bioreactor, post-treatment unit and sludge pits. / Shifrin S.M., Ivanov G.V. et al. Wastewater treatment of meat and dairy industry enterprises. M .: Light and food industry, 1981, C.S27-228 /.

Wastewater from the pumping station, on which the grilles are installed, is fed into the receiving chamber, passed through a sand trap and subjected to biological treatment in a bioreactor - aeration tank settling tank operating in the mode of extended aeration. For wastewater treatment, biologists are provided in the station diagram.

ponds. Mineralized excess sludge from the bioreactor is fed for drying to sludge sites.

The disadvantages of this station are that it occupies large areas, in particular, due to the use of biological ponds as a secondary treatment unit, and also does not provide a sufficiently high degree of purification from nitrogenous substances.

The technological scheme of the proposed biological wastewater treatment plant of the dairy is shown in the drawing.

The dairy biological wastewater treatment plant contains a water supply device for treatment 1, a receiving station of the pumping station 2 with a grill, a sand trap 3 with a biological water treatment pipe 4 and a sand extraction device 5, a wastewater mixing tank with silt mixture 6, made in the form funnels and equipped in the lower part of the discharge pipe with air-saturated sludge mixture 7, a bioreactor 8, made in the form of a housing 9 with a conical or pyramidal bottom, equipped with an integrated sludge mixture chamber 10, in the form of a funnel, inside of which there is an airlift 11, the outlet of which is placed in the chamber for mixing wastewater and sludge mixture 6, with a stirring device 12 located at the periphery of the sludge mixture chamber 10 and at the level of its upper edge, and around the periphery of the upper part of the bioreactor body 9 8, there is a tray for treating purified water 13 connected to a pipeline for treating treated water 14, bioreactor 8 is equipped with a pipe for draining excess activated sludge 15, made in the form of a siphon, and a pipeline for supplying water to a biological tank the stack 4 is connected to the wastewater mixing chamber with the sludge mixture 6, and the drain pipe of the air-saturated sludge mixture 7 is connected to the conical or pyramidal bottom of the housing 9 of the bioreactor 8, a post-treatment unit consisting of a purified wastewater mixing chamber with reagents 16 and a clarifier 17 of the cylindrical shape equipped with a block of thin-layer sedimentation 18 in the upper part and a clarified water collecting tray 19 connected to the clarified water pipeline 20, and in the lower part, a sediment discharge pipeline 21. Sand removal device 5 from sand traps 4 and the drainage pipe of excess activated sludge 15 are connected to sludge pads 22.

The station operates as follows.

Dairy waste water through the water supply device for treatment 1 is fed to the receiving tank of the pumping station 2, where they pass through the grate and then are pumped to the sand trap 3, from where they enter the mixing chamber of the wastewater and sludge mixture 6 through the water supply pipe for biological treatment 4 , The sand is poured on 1 in the sand trap 3 bunkers, from where it is fed to the sludge pads 22 through the sand removal device 5. The sludge mixture is fed from the sludge mixture chamber 10 into the mixing chamber 6 by airlift 11, into which air is supplied. When pumping the sludge mixture, it simultaneously saturates it with atmospheric oxygen. The air-saturated sludge mixture from the chamber 6 is fed into the lower conical part of the bioreactor 8 through the discharge pipe of the air-saturated sludge mixture 7. When entering the cone and raising the mixture, biochemical p -t & ll

1 the above processes, quite clearly separated by the height of the housing 9 depending on the speed of movement. As the sludge mixture moves upward, oxidation of organic compounds takes place, then denitrification occurs in the anoxic zone. Slurry of activated sludge coarsens and creates a fairly stable layer of granular activated sludge. In this layer, further decomposition of organic substances occurs, at the same time, upward stabilization occurs and the upper boundary of the granular activated sludge layer is established. A part of the stream, equal to the inflow, rises to the upper zone of the bioreactor 8, where it is collected in a tray of purified water 13 and is fed to the post-treatment via the pipeline for the removal of purified water 14. The main part of the sludge mixture flow by the mixing device 12 is diverted to the sludge mixture chamber 10 through the upper edge. Excess activated sludge is discharged to the sludge sites 22 through the excess activated sludge removal pipeline 15. Excess sludge is discharged periodically through a siphon pipe in such a way that sludge is discharged gradually over the course of the day with an open valve.

Thus, the aerobic and anoxic conditions for activated sludge that are combined in the proposed device in space and time allow more efficient removal of not only organic compounds but also nitrogenous substances from water, which is also facilitated by repeated circulation of the sludge mixture, which allows to obtain the age of activated sludge required to intensify the processes of nitrification and

iO

nitrification.

The purified water from the bioreactor 8 through the pipeline for the removal of purified water for purification 14 by gravity enters the mixing chamber 16, which also serves reagents - solutions of coagulant and disinfectant. From the mixing chamber 16, the mixture is fed to clarifier 1 with a suspended layer in which it moves from bottom to top. In the clarifier, coagulation of dissolved organic matter and its precipitation takes place, and a suspended layer is formed through which the coagulated suspension is filtered. Then the water is clarified in the thin-layer sedimentation unit 18 located in the upper part of the clarifier 17, collected in the clarified water tray 19 and discharged through the clarified water discharge pipe 20. The sediment is removed from the system through the sediment removal pipe 21.

The use of clarifier 1 as a purification unit at the station with a preliminary chamber for mixing purified water with reagents 16 can significantly reduce the area occupied by the station, which reduces the cost of cleaning.

Thus, the use of the proposed biological wastewater treatment plant of the dairy allows to increase the degree of purification of water from suspended, colloidal, organic contaminants and nitrogen compounds, as well as to reduce the occupied area. Authors: L - / Sirota M.N.

V№f5 / i

/ V.

 Sidorov E.P.

Claims (1)

BIOLOGICAL WASTE WATER TREATMENT PLANT OF THE DAIRY PLANT, comprising a purification water supply device, a pump station receiving chamber with a grill, a sand trap, a biological purification water supply pipe, a bioreactor made in the form of a body with a bottom, with a purified water drainage channel, an excess activated sludge discharge pipe and airlift for pumping sludge mixture, a post-treatment unit and sludge sites, characterized in that the station is equipped with a chamber for mixing wastewater with sludge mixture, made in the form of a funnel, provided in the bottom of the first part of the discharge pipe of the sludge mixture saturated with air, the bioreactor is equipped with a built-in sludge chamber made in the form of a funnel, inside of which there is an airlift, the outlet of which is located in the chamber for mixing wastewater and sludge, with a mixing device located at the periphery of the sludge chamber and at its upper edge, and the purified water drain pipe for purification connected to the purified water drain tray, the bottom of the bioreactor body is conical or pyramidal, the hatch drain pipe full-time activated sludge is made in the form of a siphon, the biological treatment water supply pipe is connected to the wastewater-sludge mixing chamber, and the air-saturated sludge discharge pipe is connected to the conical or pyramidal bottom of the bioreactor, the aftertreatment unit consists of a purified wastewater mixing chamber with reagents and a clarifier with a cylindrical conical shape, equipped in the upper part with a thin-layer sedimentation unit and a clarified water collecting tray connected to the clarified water pipeline, and in the lower part Asti - sediment discharge pipeline.