KR101932611B1 - Advanced water treatment system using Heat-Recovery system for Prevention of Microorganism Activation Reduction by temperature difference of water treatment step - Google Patents

Abstract

Disclosed is an advanced sewage treatment system capable of preventing the deterioration of microbial activity in a bioreactor by raising the temperature of an influent through waste heat of an effluent discharged after a biochemical water treatment process in which treatment water in a discharge tank is circulated to a flowrate balancing tank. The present invention includes: a first flowrate balancing tank taking sewage from a side and connected to an external heating device; a second flowrate balancing tank connected to a side of the first flowrate balancing tank through a floodgate and including a heat exchange part; a bioreactor connected to the other side of the first flowrate balancing tank, and growing microorganisms and decomposing pollutants; a discharge tank formed at the rear end of the bioreactor, and storing and discharging treatment water treated through the bioreactor; and a heat recovery system transferring waste heat contained in the effluent stored in the discharge tank to the heat exchange part of the second flowrate balancing part.

Description

Technical Field [0001] The present invention relates to an advanced water treatment system using a heat recovery system for preventing degradation of microbial activity due to a temperature difference in a water treatment process,

The present invention relates to an advanced water treatment system, and more particularly, to an advanced water treatment system using a heat recovery system for preventing degradation of microbial activity due to a temperature difference in a water treatment process.

In general, the treatment methods for sewage and wastewater can be roughly divided into physical methods, chemical methods and biological methods, and each treatment method is determined by the characteristics of the sewage to be introduced, the use of the treated effluent, .

Nitrogen and phosphorus contained in sewage and wastewater belong to nutrient salts. If they can not be removed properly, they will become a main cause of eutrophication when they are discharged, causing abnormal propagation of algae in polluted waters, polluting water supply and industrial water. It is necessary to effectively remove nitrogen and phosphorus contained in the waste water and wastewater.

Conventional biological nitrogen and phosphorus removal methods include anaerobic / anoxic / aerobic (A2 / O), Bardenpho and UCT processes. Each of the above processes basically has at least one anaerobic tank, anoxic tank, and oxic tank, and is deformed in processes such as internal transportation and sludge transportation.

In recent years, MBR (Membrane Bioreactor) process combining biologic treatment and membrane has attracted attention in order to secure stable reuse. Such an MBR process is capable of maintaining the concentration of microorganisms (MLSS: Mixed Liquor Suspended Solid) as high as about 5000 to 1000 mg / L, which is advantageous in increasing the biological nitrogen removal performance.

However, there is a problem that the activity of nitrification and denitrification microorganisms for nitrogen removal is lowered at a temperature of about 13 캜 or lower in winter. Korean Patent Publication No. 2011-0044401 discloses an advanced sewage treatment facility having a carrier and a membrane, but does not describe the problem of degradation of microorganisms due to temperature drop of influent water.

The present invention provides a sewage elevation treatment system that uses waste heat of effluent water discharged after a biochemical water treatment process to increase the temperature of influent water to prevent degradation of microbial activity in the bioreactor.

According to an aspect of the present invention, there is provided a water treatment system comprising: a first flow rate adjusting tank having a heating unit connected to an external heating device, A second flow rate regulating tank connected to one side of the first flow rate regulating tank by a gate and having a heat exchange unit therein; A bioreactor connected to the other side of the first flow rate adjusting tank and generating microbial growth and decomposition of contaminants; An efflux tank configured to be disposed downstream of the bioreactor and to receive and discharge the treated water treated by the bioreactor; And a heat recovery system for transferring the waste heat contained in the discharge water contained in the discharge tank to the heat exchange unit of the second flow rate adjustment tank.

The heat recovery system further includes a high temperature transportation pipe provided at the side of the discharge tank for transferring the treated water in the discharge tank to the heat exchange unit of the second flow rate adjustment tank; A low temperature transportation pipe provided on the other side of the discharge tank for transferring the treated water having passed through the heat exchange unit of the second flow rate adjustment tank to the discharge tank; And a circulation pump circulating the treatment water in the discharge tank along the high-temperature transportation pipe and the low-temperature transportation pipe.

And the temperature of the first flow rate adjusting tank is maintained at 13 to 30 DEG C, and the temperature of the second flow rate adjusting tank is maintained at 10 DEG C or more.

The present invention provides a sewage elevation treatment system for preventing degradation of microbial activity in a biological reactor by raising the temperature of influent water by using waste heat of effluent discharged after a biochemical water treatment process by circulating treated water in a discharge tank through a flow rate adjusting tank It is possible.

1 is an overall process diagram of a sewage elevation treatment system in accordance with an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to denote the same parts throughout the specification, and the details of the present invention will be described with reference to the drawings. Also, throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements, unless specifically stated otherwise.

The advanced water treatment system 100 according to the present invention includes first and second flow rate regulating vessels 111 and 112, a bioreactor 120, a discharge vessel 130 and a heat recovery system 140.

In order to solve the problem that the activity of the bioreactor 120 is lowered at a low temperature, the flow rate adjusting tank is divided into a first and a second, and the waste heat of the external heating device and the effluent water is recovered, Is maintained.

Accordingly, the first flow rate adjusting tank 111 is provided with a heating unit H1 connected to an external heating device A, and the second flow rate adjusting tank 112 is connected to the heat recovery system 140 through the heat recovery system 140, The heat exchanging unit H2 is provided.

The flow rate adjusting tanks 111 and 112 prevent the overload of the system by controlling the flow rate of the wastewater flowing into the bioreactor 120. Therefore, it is possible to provide a contaminant processor for filtering the contaminants of the wastewater at one side.

In addition, the first flow rate adjusting tank 111 is an in-line type tank in which wastewater is directly introduced into one side and the influent water is discharged via the bioreactor 120. The second flow rate adjusting tank 112 is connected to the first flow rate adjusting tank 111 ) And a hydrological gate to temporarily store the flow rate exceeding the maximum flow rate and distribute the flow rate to the bioreactor at a time when the flow rate is low.

The bioreactor 120 is connected to the other side of the first flow rate regulator 111 and is a place where a biological treatment process such as a single bioreactor, an AO process, and an AO process, in which the growth of microorganisms and the decomposition of contaminants occur, And does not limit the reaction by a specific microorganism. In the case of the AO process and the A2O process, the surplus sludge can be discharged from the sedimentation basin or the sludge storage tank (S). The excess sludge is discharged out of the system to remove the phosphorus. Therefore, an excess sludge pump may be provided in the bioreactor, the secondary settling tank, or the stabilization conveying tank.

The bioreactor 120 may further include a membrane filtration tank 124, which may be an upflow or a downflow type bioreactor provided with a microbial carrier, and which performs solid-liquid separation using sludge-containing solid matter and treated water through an immersed flat membrane can do.

The AO method is arranged in the order of the anaerobic tank and the aerobic tank. In the case of the A2O method, the anaerobic tank 121, the anoxic tank 122, and the aerobic tank 123 are arranged in this order. The amount of nitrate nitrogen introduced into the anaerobic tank can be minimized. The anaerobic tank and the anoxic tank are denitrified and the anoxic tank is nitrified. The influent and the activated sludge (external circulation) are introduced into the anaerobic tank and the aerobic tank activated sludge (internal circulation) is circulated to the anaerobic tank.

The A2O process has the advantage that it can remove both nitrogen and phosphorus, can provide the necessary degree of alkalinity for nitrification, has good sedimentation property of sludge, and is relatively simple in operation, while RAS containing nitrate nitrogen has an advantage The nitrogen removal is limited by the internal recycle cost, and the BOD / P ratio is higher than that of the AO method. Therefore, an external carbon source may be required to be supplied.

The anaerobic tank is maintained in an oxygen-free state, and the nitrogen in the anaerobic tank is treated by a process of ammonia-> nitrate-> nitrite (exhalation) -> nitrogen (anoxic region) Excess enrichment (exhalation region) and excretion (anaerobic region). Using an underwater mixer, externally transported carbon source and phosphorus removal microorganism are homogeneously stirred to consume carbon source and induce smooth release of phosphorus.

In the anaerobic tank, organic matter contained in sewage water is anaerobically fermented and converted into a fermentation product such as organic acid. The organic acid is absorbed by microorganisms such as PAO and stored as PHA. Therefore, the treated water in the anaerobic tank includes organic acids, PHA stored in PAO, and non-fermented organic matter. The treated water having passed through the anaerobic tank 121 is transferred to the anoxic tank 122.

The Anoxic Tank is a denitrification process for degassing the form of the nitrified nitrogen in the form of N _2. The denitrification process is carried out by transferring the electrons generated by the oxidation of the organic matter as the electron donor to the nitrate of the electron acceptor to denitrify the nitrate Reaction tank. Pseudomonas, Bacillus, Mirococcus, Achromobacter, etc., which are denitrification-related microorganisms, denitrify the nitrate nitrogen in the treated water returned from the aerobic tank by using the remaining carbon source consumed in the anaerobic tank. The treated water passing through the anoxic tank 122 is transferred to the oxic tank 123.

The aerobic tank is a place where the ammonia nitrogen or the nitrogen compound is converted into the form of nitrate nitrogen-> nitrite nitrogen, and the organic matter as the electron donor is oxidized and the electron is transferred to the oxygen which is the electron acceptor, And the organic matter is supplied from the anaerobic tank 121 through the anoxic tank 122 through the treated water. PAO, which is present in the treated water and stores organic PHA in the body, decomposes the PHA in an oxic tank to synthesize cells, and absorbs phosphorus excessively and stores it in cells in the form of multiple-P.

Nitrosomonas and Nitrobacter are the nitrification microorganisms of the aerobic basin, and the nitrification process takes a long time and the residence time (HRT) of the aerobic basin is designed to be about 4 to 6 hours or more. The concentration of DO in the aerobic tank can be kept high through the aerosol under the inner membrane separator and the solids outside the separator can be desorbed and the homogenization of the nitrifying microorganisms and the PAOs It is possible to smoothly overproduce nitrification and phosphorus.

The efflux tank 130 is disposed downstream of the bioreactor 20 and receives and discharges the treated water treated by the bioreactor 120. Generally, the temperature of the effluent water is in the range of 13 ~ 15 ° C due to aeration and microbial reaction heat during operation of the bioreactor (120). The present invention can recover the waste heat of the discharged water using a circulating pump or a heating pump to raise the temperature of the second flow rate regulator 112 to a temperature suitable for microbial activity.

The heat recovery system 140 transfers the waste heat contained in the discharge water contained in the discharge tank 130 to the heat exchange unit of the second flow rate adjustment tank 112 to maintain the water temperature of the second flow rate adjustment tank 112 suitable for microbial activity .

Therefore, the heat recovery system 140 is provided at one side of the discharge tank 130, and is provided with a high-temperature transportation pipe 130 for transferring the treated water in the discharge tank 130 to the heat exchange unit H2 of the second flow- (141); A low temperature transportation pipe 142 provided on the other side of the discharge tank 130 for transferring the treated water having passed through the heat exchange unit H2 of the second flow rate adjustment tank 112 to the discharge tank 130; And a circulation pump 143 for circulating the treated water of the discharge tank 130 along the high temperature transportation pipe 141 and the low temperature transportation pipe 142.

The circulation pump discharges the discharged water stored in the discharge tank to the heat exchange unit H2 of the second flow rate regulator 112 through the high temperature transport pipe 141. [ The heat-exchanged discharged water in which the inflow water in the second flow rate adjusting tank 112 is heated through the heat exchange in the heat exchange unit H2 is joined to the discharge tank 130 again through the low temperature transportation pipe 142 and discharged.

In the advanced water treatment system including the heat recovery system 140 according to the present invention, the temperature of the first flow rate adjusting tank is maintained at 13 to 30 DEG C, the temperature of the second flow rate adjusting tank is maintained at 10 DEG C or higher, It is possible to maintain the activity of the edible microorganism.

The preferred embodiments of the present invention have been described in detail with reference to the drawings. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

Accordingly, the scope of the present invention is defined by the appended claims rather than the description of the invention, and all changes or modifications derived from the meaning, scope and equivalence of the claims are deemed to be included in the scope of the present invention. .

100: sewage elevation treatment system 111: first flow control tank
112: second flow rate adjusting tank 120: biological tank
121: anaerobic tank 122: anoxic tank
123: cockpit 124: membrane separation tank
130: Discharging tank 140: Heat recovery system
141: high temperature transport pipe 142: low temperature transport pipe
143: Circulating pump A: Heating device
H1: Heating part H2: Heat exchange part
S: Sludge reservoir

Claims (3)

A first flow rate regulating tank having a heating unit into which sewage is introduced into one side and connected to an external heating device;
A second flow rate regulating tank connected to one side of the first flow rate regulating tank by a gate and having a heat exchange unit therein;
A bioreactor connected to the other side of the first flow rate adjusting tank and generating microbial growth and decomposition of contaminants;
An efflux tank configured to be disposed downstream of the bioreactor and to receive and discharge the treated water treated by the bioreactor; And
And a heat recovery system for transferring the waste heat contained in the discharge water contained in the discharge tank to the heat exchange unit of the second flow rate adjustment tank,
The heat recovery system includes a high-temperature transportation pipe provided at the side of the discharge vessel for transferring the treated water in the discharge vessel to the heat exchange unit of the second flow rate adjustment tank;
A low temperature transportation pipe provided on the other side of the discharge tank for transferring the treated water that has passed through the heat exchange unit of the second flow rate adjustment tank to the discharge tank; And
And a circulation pump circulating the treatment water in the discharge tank along the high-temperature transportation pipe and the low-temperature transportation pipe,
Wherein the temperature of the winter season of the first flow rate adjusting tank is maintained at 13 to 30 DEG C and the winter season temperature of the second flow rate adjusting tank is maintained at 10 DEG C or higher using only waste heat contained in the discharged water,
Wherein the first flow rate adjusting tank is an inline type tank in which the wastewater is directly introduced into one side and the influent water is discharged through the bioreactor and the second flow rate adjusting tank is connected to the first flow rate adjusting tank by a water gate, Wherein the system is an off-line system.
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