RU165513U1 - MEMBRANE APPARATUS MODEL FOR A BIOREACTOR - Google Patents

Abstract

A model of a membrane apparatus for a bioreactor that treats wastewater using activated sludge and consisting of a nitrification zone with a membrane apparatus installed in it, an aerobic zone, a system for returning nitrified activated sludge to the denitrification zone, and also auxiliary equipment and pipelines, characterized in that the membrane apparatus made with 24 ceramic membranes packed vertically in a block; holes with a diameter of 0.5-1 mm located around each ceramic m are provided in the lower part of the apparatus mbrany.

Description

The utility model relates to the field of treatment of urban weakly concentrated wastewater and highly concentrated industrial wastewater, and can also be used in the preparation of natural water for drinking purposes and industrial water supply.

A known installation for biological wastewater treatment (RF patent No. 75651, 08/20/2008, CO2F 3/30, C02F 3/12), consisting of a pipeline for supplying untreated wastewater, a bioreactor with an aeration system, an immersion membrane separator equipped with membrane modules with cartridges, a pipeline for the removal of purified water, pipelines for circulation of activated sludge and removal of excess activated sludge for dehydration, and a backwash system for membrane elements.

The disadvantage of this installation is the device of an additional post-treatment unit, which increases capital and operating costs during the construction of sewage treatment plants (OSK).

Also known is a biological wastewater treatment plant (RF patent No. 141341, 05/27/2014, CO2F 3/30), consisting of a pipeline for supplying untreated wastewater, a denitrification zone, a nitrification zone, a membrane tank, an aeration system, a cleaned collection tank water, systems for the regeneration of membrane elements by backwashing of purified water, periodic chemical washing with solutions of sodium hypochlorite and citric acid, a block of degassing activated sludge under vacuum based on the Aeroklin unit, as well as the introduction of ferric chloride or another coagulant to remove phosphates.

The disadvantage of this installation is the increase in the construction cost of a complex of structures due to the installation of a degassing unit.

A membrane apparatus is also known (RF patent No. 2412749, February 27, 2011, B01D 63/06), comprising a membrane module housing made of tubular ceramic filtering membranes, supply and discharge pipes for the source and purified waste water, concentrate, and also sealant.

The disadvantage of this apparatus is an increase in construction and operating costs.

The closest in technical essence to the claimed utility model is a method for treating domestic and industrial wastewater (RF patent No. 2547734, 04/10/2015, C02F 9/14, C02F 9/02, C02F 3/30, C02F 1/32 , B01D 36/00), consisting of a denitrification zone, an aerobic zone and a nitrification zone, tanks for collecting purified water, circuits for returning activated sludge to a denitrification zone or for disposal, aeration systems and groups of blowers, tanks for storing reagents intended for chemical washing membrane modules, chlorine gel solution tank sludge, filtrate pumping and membrane module flushing.

The disadvantage of this method is the inefficient regeneration of the outer surface of the membrane.

The objective of the claimed utility model is to increase the efficiency of membrane regeneration, and therefore:

- Reducing the flow rate of wash water to 1-5% of the daily amount of effluent entering the treatment due to the use of more efficient membrane regeneration by air;

- An increase in the duration of the filtration cycle through the use of continuous effective regeneration of the outer surface of the membranes with air;

- Improving the quality of wastewater treatment due to the effective regeneration of the outer surface of the membrane.

The problem is solved in that in the model of a membrane apparatus for a bioreactor that treats wastewater using activated sludge and consisting of a nitrification zone with a membrane apparatus installed in it, an aerobic zone, a system for returning nitrified activated sludge to the denitrification zone, as well as auxiliary equipment and pipelines , according to a utility model, the membrane apparatus is made with 24 ceramic membranes packed vertically in a block, holes with a diameter of 0.5-1 mm are provided in the lower part of the apparatus, aspolozhennye around each single channel of the ceramic membrane to allow cleaned of biofouling and clogging the outer surface of the ceramic membranes located in the central part of the module, and the periphery.

In FIG. 1 and FIG. Figure 2 shows the membrane bioreactor diagrams and the longitudinal section of the membrane apparatus (7), including the supply of clarified waste fluid (1), denitrification zone (2) with paddle mixers (3), aerobic zone (4) and nitrification zones (5) with membrane aerators ( 6), a membrane apparatus (7), consisting of 24 ceramic membranes (8), an upper chamber (9), a lower chamber (11), an air chamber (10), the air from which flows through openings (14), tubes (13) supplying compressed air to the air chamber (10), pipes (12), exhaust

purified water, and at the same time intended for supplying compressed air and water during the regeneration of membranes, as well as sealant (15), a reservoir (16) for collecting biologically treated wastewater, a blower (17) for supplying compressed air to the aerobic zone (4) and a nitrification zone (5), a compressor (18) for supplying compressed air through openings (14) for continuous regeneration of the outer surface of ceramic membranes (8), a vacuum pump (19) for pumping treated wastewater into a tank (16), circulating activated sludge (20) with circulation pump (21) and discharge pipe excess activated sludge (24) for treatment, removal of treated effluents (25) from the tank (16), a washing pump (22), a blower (23) for supplying air into the ceramic membranes (8) for their regeneration, a tank with sodium hypochlorite solution (26), a reservoir with a citric acid solution (27), a sodium hypochlorite feed pump (28), a citric acid supply pump (29), as well as a bottom hole (30) and a perforated baffle (31).

The membrane apparatus (7) in the bioreactor operates as follows. The clarified wastewater (1) enters the denitrification zone (2), circulating activated sludge (20) from the nitrification zone (5) containing nitrites and nitrates is also supplied here with a circulation pump (21). Active sludge is a zooglide cluster of organic origin, populated by bacteria, protozoa and microscopic animals. The denitrification zone (2) is designed to reduce nitrogen nitrates and nitrites to gaseous forms of nitrogen: NO, N ₂ O, N ₂ depending on the reaction of the medium. At a pH of more than 7.3, nitrites and nitrates are reduced to elemental nitrogen N ₂ , at a pH of less than 7.3, the final product of nitrogen reduction is NO and N ₂ O. For the vital activity of denitrification microorganisms in the denitrification zone (2), conditions are maintained under which the concentration dissolved oxygen is in the range of 0-0.5 mg / L. In conditions of acute oxygen deficiency, microorganisms are forced to use the associated oxygen of nitrites and nitrates for their breathing. In the denitrification zone (2), paddle mixers (3) are provided to maintain activated sludge in suspension. From the denitrification zone (2), the sludge mixture through the bottom hole (30) is transferred to the aerobic zone (4), intended for the oxidation of organic substances not in demand in the denitrification zone (2). Oxidation occurs under aerobic conditions created by air pumped through membrane aerators (6); at this stage of purification, the biochemical oxygen consumption (BOD _floor ) of the waste fluid is reduced to 15-20 mg / l. Next sludge mixture

through a perforated septum (31) it enters the nitrification zone (5), also equipped with membrane aerators (6), where ammonium nitrogen is first oxidized to nitrites and then nitrates. Membrane devices (7) are mounted in the nitrification zone (5), since at this stage of wastewater treatment all colloidal particles and macromolecules that cause the fast clogging of ceramic membranes are removed from it (8). Excessive active formed in the biological system is removed through the pipeline for the removal of excess activated sludge (24) for further processing and disposal. Filtration of a mixture of activated sludge and wastewater is carried out through ceramic membranes (8) with a pore size of 0.05-0.5 microns. Filtration of the sludge mixture occurs under a weak vacuum created by a vacuum pump (19). During the operation of the module, the surface of ceramic membranes (8) is clogged with solid particles of activated sludge and is surrounded by an organic mass, inhabited mainly by bacteria. Clogging occurs as a result of penetration of activated sludge particles into the pores and labyrinths of ceramic membranes (8), and biological fouling is possible only on the surface of ceramic membranes (8) due to the presence of a natural biopolymer in activated sludge. In order to reduce biofouling and increase the duration of the filtration cycle, continuous regeneration of the outer surface of ceramic membranes (8) with air through openings (14) supplied by the compressor (18), as well as air bubbles of membrane aerators (6) designed to saturate the sludge mixture with oxygen, is provided. The number of holes (14) around the ceramic membranes (8) should be determined from the strength of the membrane apparatus (7) and be within 10-14 pieces with a diameter of 0.5-1 mm, with a diameter of ceramic membranes (8) 10 mm. The intensity of the compressor air supply (18) is in the range of 3.5-10 m ³ / m ² · h. The liquid filtered through ceramic membranes (8) is supplied to a reservoir (16) to collect biologically treated wastewater, and then, through a drain of treated effluents (25), is discharged into a reservoir. Purified water is used for its own needs for the regeneration of membranes with water. Membrane devices (7) are installed strictly in the center above the membrane aerators (6). For the regeneration of membrane devices (7), every 30-50 minutes it is planned to turn on a blower (23), which supplies compressed air into the ceramic membranes (8) through a pipe (12), due to which contaminants are removed from the outer surface of the ceramic membranes (8). After air purging, the ceramic membranes (8) should be flushed with water pumped by the flushing pump (22) into

pipeline (12), which is also fed into ceramic membranes (8). The membrane apparatus can be regenerated with chemicals: sodium hypochlorite (NaOCl) supplied by a pump for supplying sodium hypochlorite (28) from a tank with a solution of sodium hypochlorite (26) and citric acid (C ₆ H ₈ O ₇ ) supplied by a pump for supplying citric acid ( 29) from a reservoir with a solution of citric acid (27). Chemical regeneration is carried out at least 2-4 times a year.

The quality indicators of the purified liquid in the installation equipped with membrane devices (7) with effective air regeneration of the outer surface of ceramic membranes (8) are presented in table 1.

As can be seen from the table, the use of the claimed utility model allows to achieve more stable operation of the bioreactor and to obtain high quality wastewater treatment, reduce the flow rate of wash water to 1-5% of the daily flow of wastewater (instead of 16-30% in hollow fiber membranes), increase the productivity of the membrane apparatus due to the constant regeneration of the outer surface of the ceramic membranes through the holes provided in the lower part of the membrane apparatus, which increases the duration of the filtration cycle and, therefore, reduces the ex luatatsionnye and capital costs of the enterprise.

Claims (1)

A model of a membrane apparatus for a bioreactor that treats wastewater using activated sludge and consisting of a nitrification zone with a membrane apparatus installed in it, an aerobic zone, a system for returning nitrified activated sludge to the denitrification zone, and also auxiliary equipment and pipelines, characterized in that the membrane apparatus made with 24 ceramic membranes packed vertically in a block; holes with a diameter of 0.5-1 mm located around each ceramic m are provided in the lower part of the apparatus mbrany.

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