KR200344882Y1 - Advanced treatment system for removing nitrogen and phosphorus - Google Patents

Abstract

Disclosed is an advanced treatment system capable of simultaneously treating nitrogen and phosphorus, which are introduced into sewage, wastewater and sewage, causing eutrophication when discharged into a stream. Such a system includes an anoxic tank, an anaerobic tank, a contact oxidation tank with a fixed bed contact medium, a membrane separation tank, and a settling degassing tank equipped with a conveying means for returning the degassed sludge to the anoxic tank while also functioning as a settling tank and a degassing tank. According to such a system, the removal efficiency of organic matter, nitrogen and phosphorus contained in sewage, waste water, sewage, etc. is improved, and perfect solid-liquid separation is possible, and inflow of raw water exceeding the design capacity, power failure, mechanical failure, etc. It can cope quickly and perfectly even in a sudden situation, so that stable water quality can be secured at all times. In addition, such a system can not only ensure stable treatment water quality by buffering action by the contact media provided in the contact oxidation tank, but also greatly reduce the initial facility cost by reducing the residence time and greatly reducing the size of the reaction tank. Since there is no use of chemicals, the maintenance cost can be minimized.

Description

Advanced treatment system for removing nitrogen and phosphorus {ADVANCED TREATMENT SYSTEM FOR REMOVING NITROGEN AND PHOSPHORUS}

The present invention relates to an advanced treatment system for removing nitrogen, phosphorus, etc. contained in sewage, wastewater, sewage, and more specifically, a biological treatment tank composed of an anoxic tank, an anaerobic tank, and a contact oxidation tank equipped with a stationary phase contact medium. In addition, the present invention relates to an advanced treatment system for efficiently removing nitrogen and phosphorus as well as organic matter contained in sewage, wastewater, and sewage under any extreme conditions by sequentially disposing a membrane separation tank and a settling degassing tank equipped with an immersion type membrane.

Conventionally, representative biological processes developed in developed countries to simultaneously remove nitrogen and phosphorus contained in sewage, wastewater and sewage are A2O (Anaerobic-Anoxic-Oxic) process, UCT process, VIP process, 5-step Badenpo ( Five-Stage Bardenpho) process.

The A2O process (anaerobic / oxygen / aerobic) is a modification of the AO process operated only by the anaerobic process and the aerobic process, and is a process in which an anoxic process for denitrification is added between the anaerobic process and the aerobic process. This process has better denitrification performance than AO process, but its performance is uncertain under cold weather operating conditions and it is operated as a complicated process compared to AO process.

The UCT process (anaerobic / anoxic / anaerobic / aerobic) is an anaerobic process, a first anoxic process, an internal conveying process from the first anoxic process to an anaerobic process, followed by a second anoxic process, an aerobic process, an aerobic process to a second anoxic process. It is a process which consists of an internal conveyance process to the process, and the process which conveys the sludge produced through such a process to a 1st oxygen-free process. As such, the inflow of nitrate into the anaerobic process is eliminated by the activated sludge conveying process which recycles the activated sludge to the anoxic process, and the elution of phosphorus in the anaerobic process is increased, and the organic matter removal in the anaerobic process is increased by the internal circulation process. This process is advantageous in that the return to the anoxic process eliminates the need for nitrate conveyance, creates a better phosphorus removal environment in the anaerobic process, and the volume of the reactor is smaller than that of the Badenpo process, but a large amount of internal circulation provides pump energy. The disadvantages include increased maintenance and maintenance, the need for drug injection, and high BOD / P ratios. In addition, the influence of temperature on the process performance of this process is not well known.

VIP process (anaerobic / oxygen / aerobic) is an anaerobic process, an anoxic process, a process in which denitrified raw water from the anoxic process is returned to a raw water inflow line into an anaerobic process, an aerobic process, and a nitrified raw water from the aerobic process is returned sludge Together with the step of being returned to the anoxic step. This process reduces oxygen demand and alkalinity consumption by returning nitrates to the anoxic process, and reduces nitrate load in the aerobic process by returning the semi-anaerobic process effluent to the anaerobic process, applying it to yearly phosphorus removal and seasonal nitrogen removal. This is advantageous in that it is possible, but a large amount of internal circulation increases the pump energy and maintenance, and the nitrogen removal ability is reduced by the low temperature, which is not practically applied in many cases.

The 5-step Badenpo process (Aerobic / Anoxic / Aerobic / Anoxic / Aerobic) is an anaerobic process, a first anoxic process, a first aerobic process, a return process from the first aerobic process to the first anoxic process, and a second anoxic process. The process consists of a confluence of the second sludge process and the sludge produced and the inflow water introduced into the anaerobic process. Compared to other phosphorus removal processes, this process has less sludge production, lower total nitrogen concentration in the treated water, and has the advantage of reducing or eliminating the need for chemical injection into the process by returning alkalinity to the process. The internal circulation increases pump energy and maintenance, requires a larger reactor volume than the A2O process described above, reduces the ability to remove nitrogen and phosphorus due to primary precipitation, and requires high BOD / P. have. In addition, the influence of temperature on the process performance of this process is not well known.

As described above, the conventional advanced treatment process and the system for removing nitrogen and phosphorus have many advantages as described above, but the change of season is obvious, that is, the change of temperature according to the season is obvious and advanced sewage of advanced countries It is not suitable to use as it is in the situation of Korea that does not match the characteristics. In addition, when the water flow characteristic is variable or the raw water is introduced in an excessive amount only by the conventional high-treatment process as described above, there is no way to cope with it.

Recently, in addition to biological treatment, a membrane separation process using a separation membrane has been developed and applied. Advanced treatment systems such as sewage, wastewater, and sewage employing separation membranes are advantageous in that they can provide high quality treatment water compared to other systems that do not use separation membranes. It is difficult to actively cope with various changes in the treatment plant such as a power failure or a mechanical failure.

In view of the problems of the prior art, the present inventors are not only expected to improve the quality of treated water while meeting the characteristics of domestic sewage, wastewater, and sewage, but also develop an advanced treatment system that can actively cope with various changes in the treatment plant. Was done.

The present invention has been devised to solve the conventional problems as described above, the object of the present invention is an immersion membrane separation tank equipped with biological treatment and immersion type membrane using an anoxic tank, anaerobic tank and a fixed-phase contact medium Simultaneous treatment with sedimentation and degassing tanks with sludge returning and discharged treated water while simultaneously performing the sedimentation and degassing functions, improves the removal efficiency of organic matter, nitrogen and phosphorus contained in sewage, wastewater and sewage. It is not only to solve the problems in the sedimentation tank by improving and perfect solid-liquid separation, but also to provide a system that can cope quickly and completely in the event of unexpected water inflow, power failure, and mechanical failure exceeding the design capacity.

1 is a schematic diagram of an advanced processing system according to an embodiment of the present invention; And

2 is a view showing in more detail the advanced processing system according to an embodiment of the present invention shown in FIG.

* Description of the symbols for the main parts of the drawings *

1: Raw water inlet line 10: Flow adjustment tank

14: diffuser 15: drum screen

16: transfer pump 18, 57: level switch

20: anoxic tank 22a, 22b, 32: stirrer

30: anaerobic tank 40: contact oxidation tank

44: diffuser 46: contact medium

50: membrane separation tank 54: diffuser

56 separation membrane, in particular submerged membrane 58 suction pump

59: flow meter 60: sedimentation degassing tank

62: return pump 64: treated water outlet

66: sludge conveying line 68: sludge storage line

70: treatment tank 80: sludge storage tank

90: washing tank 100: blower

In order to achieve the above object, the present invention,

(a) an anaerobic bath equipped with a stirrer to denitrify the pretreated raw water;

(b) an anaerobic tank in which the treated water flows from the anoxic tank and stores organic matter in the form of poly-β-hydroxybutyrate (PHB) in an anaerobic state and is equipped with a stirrer for inducing phosphorus release;

(c) a contact oxidation tank equipped with a fixed bed contact medium and an aeration device for oxidizing the organic matter of raw water and ammonia nitrogen (NH ₄ ⁺ -N) induced by phosphorus in the anaerobic tank by microorganisms;

(e) a membrane separation tank having an immersion type membrane and an aeration device for solid-liquid separation of the raw water treated from the contact oxidation tank into sludge-containing solid material and treated water;

(g) a precipitation degassing tank for inducing precipitation while removing dissolved oxygen dissolved in the sludge-containing solid material separated in the membrane separation tank; And

(f) means for returning the sludge-containing solid material from which dissolved oxygen has been removed from the settling degassing tank to an anoxic tank,

The sedimentation degassing tank has an outer shape that gradually narrows down toward the inside, and removes organic matter, nitrogen, and phosphorus provided with a treated water outlet at a point higher than the effective depth so that the excess amount of the solid-liquid separated treated water can flow out by sedimentation. Provide an advanced processing system.

As mentioned above, the advanced treatment system of the present invention simultaneously performs biological treatment using an anoxic tank, an anaerobic tank, and a contact oxidation tank equipped with a fixed bed contact medium, an immersion membrane separation tank equipped with a immersion membrane, a precipitation function, and a degassing function at the same time. By simultaneously carrying out the physical treatment using the sedimentation degassing tank which has the structure of returning the sludge and discharging the treated water, it improves the removal efficiency of organic matter, nitrogen and phosphorus contained in sewage, wastewater, sewage, etc. Not only does it solve the problems in the settling tank, it can also respond quickly and completely to unexpected situations such as inflow of raw water, power outage, and mechanical failure exceeding the design capacity.

As used herein, the term "reactor" refers to a flow control tank, an anoxic tank, an anaerobic tank, a catalytic oxidation tank, a membrane separation tank, a precipitation degassing tank, etc., unless otherwise specified, the tank in which the reaction is performed in the same paragraph. do.

Hereinafter, with reference to the accompanying drawings will be described in detail the best embodiment of the present invention. The following embodiments are merely intended to explain the present invention, and the present invention is not limited to these embodiments.

1 and 2, sewage, waste water, sewage, etc. (hereinafter, “raw water”) are introduced into the flow rate adjusting tank 10 through the raw water inflow line 1. As shown in the flow rate adjustment tank 10, as well as maintaining a constant concentration of the introduced raw water as well as the acid pipe 14 to prevent corruption due to sedimentation, the raw water treated in the reaction tank 10 as a post-treatment process One or more transfer pumps 16 for conveying and level switches 18 are provided for sensing the amount of incoming water to regulate the operation of the transfer pump 16.

The raw water that has passed through the flow adjusting tank 10 is transferred to the drum screen 15 by the transfer pump 16 so that the solid matter in the raw water is removed to the fine particles, and the raw water from which the solid matter is removed is transferred to the anoxic tank 20. . In the oxygen-free tank 20, the nitrogen-free nitrogen (e.g., NO ₃ -N) in the sludge-containing solid material returned from the sedimentation degassing tank 60, which will be described later, using the organic matter of the treated water introduced from the flow regulating tank 10, is anoxic A denitrification reaction occurs in which nitrogen gas (N ₂ ) is released by reduction at. That is, in this denitrification step, the organic matter is oxidized by denitrification bacteria using nitrate nitrogen as the electron acceptor instead of oxygen, and the nitrate nitrogen is reduced to nitrogen gas. The nitrogen gas reduced through this process is finally released to the atmosphere and removed. At this time, the oxygen-free tank 20 is agitator (22a) (22b) for maximizing the reaction by providing a lot of contact opportunities between the incoming raw water and the sludge-containing solid material conveyed from the sedimentation degassing tank 60 which will be described later soaking ) Is provided. The oxygen-free tank 20 may be operated in the form of one reactor, but when considering the efficiency of the treatment, it is preferable to operate in the form of two or more reactors as shown in FIG.

Raw water denitrified in the anaerobic tank 20 is transferred to the anaerobic tank 30. In the anaerobic tank 30 under anaerobic conditions, denitrified raw water in the anaerobic tank 20 is treated with anaerobic microorganisms to release poly-β-hydroxybutyrate as an o-phosphate, thereby releasing phosphorus. . In this case, the anaerobic tank 30 is preferably provided with a stirrer 32 for the purpose of maximizing the reaction.

In the anaerobic tank 30, raw water induced with phosphorus release is transferred to the contact oxidation tank 40. The contact oxidation tank 40 has a contact medium, especially in the form of a rope, to which microorganisms are attached to oxidize (eg, NO ₃ -N) organic matter and ammonia nitrogen (NH ₄ ⁺ -N) remaining in the introduced raw water. The stationary phase contact medium 46 is provided. Due to the use of this stationary phase contact medium 46, orthophosphate, which has been released from the anaerobic tank 20, is synthesized up to about 8 times the amount of poly-β-hydroxybutrate, which is a polymeric material. In addition, by the use of such a contact medium, the contact time of the raw water and the microorganism flowing into the reaction tank 40 is increased, thereby reducing the size of the reaction tank 40, resulting in an effect of reducing the size of the entire reaction tank. On the other hand, the contact oxidation tank 40 is provided with a diffuser 44 which is an aeration device in addition to the above contact medium.

Raw water treated in the contact oxidation tank 40 is transferred to the membrane separation tank 50. The membrane separation tank 50 performs almost the same function as the above-described contact oxidation tank 40, and solid-liquid with sludge-containing solid material and treated water by using the separation membrane in the reaction tank 50, in particular, the immersion membrane 56. In this case, since the pores of the separation membrane is smaller than the size of E. coli, suspended matter and E. coli are filtered. The separation membrane, in particular the submerged membrane 56, is cleaned in a separate cleaning bath 90, in some cases chemically cleaned, in the event of fouling that causes clogging of the membrane. In addition to the above-described configuration, the membrane separation tank 50 according to the present invention is provided with a sleeve tube 61 in fluid communication with the precipitation degassing tank 60 described below. The solid-liquid separated treatment water is discharged by being discharged to the treatment water tank 70 through the flow meter 59 by pumping by the suction pump 58 by the operation of the level switch 57, and the sludge-containing solid material is described later. 60, it is conveyed through the sleeve tube 61.

Thereafter, the sludge-containing solid material introduced into the settling degassing tank 60 through the sleeve tube 61 as described above is solid-liquid separated again while undergoing a process of removing dissolved oxygen. Part of the solid-liquid separated sludge-containing solid material is usually conveyed to the anoxic tank 20 via the sludge conveying line 66 by pumping by the conveying pump 62 and the other part through the sludge storage line 68 to the sludge storage tank ( 80) to be processed. However, when the treatment plant is difficult to operate normally due to inflow of raw water exceeding the design capacity, power failure, mechanical failure, membrane cleaning due to clogging of the separator, etc., the treated water outlet 64 provided in the settling degassing tank 60 More specifically, only the treated water of the upper liquid-separated layer is discharged through the treated water outlet 64 provided at a position higher than the effective depth of the settling degassing tank 60 so that the treated water exceeding the effective depth is automatically discharged. Of course, in this case, the sludge settling and dissolved oxygen removal are performed simultaneously in the settling degassing tank. In case of emergency, raw water in excess of the designed capacity is introduced and periodic membrane cleaning is often occurred in actual sewage, wastewater, and sewage treatment. Considering this reality, the system according to the present invention can cope with the same configuration perfectly. In addition, the settling degassing tank 60 added to the system according to the present invention has a function of removing dissolved oxygen as described above to facilitate the release of N ₂ by the denitrification reaction in the oxygen free tank 20. do.

Precipitation degassing tank 60 used in the system according to the present invention is preferably to have an appearance that is gradually narrowed toward the bottom to smoothly perform the function of the settling tank.

In the system according to the present invention, the diffuser 14, 44, 54, which is an aeration device provided in each reactor, may have a structure for supplying air by an individual blower. It is advantageous to have a structure which is fed by one blower 100 as described. The blower 100 not only aeration of the raw water by supplying air to each reactor, but also serves to improve the purification efficiency by maximizing the contact opportunity between the microorganism and the food.

As described above, the system according to the present invention is a biological treatment using an anoxic tank, an anaerobic tank and a fixed bed contact medium, and an immersion membrane separation tank equipped with a immersion type membrane and a precipitation and degassing tank having an optional precipitation and degassing function. In parallel with the physical treatment, it improves the removal efficiency of organic matter, nitrogen, phosphorus, etc. contained in wastewater, sewage, etc. and solves problems in the sedimentation tank through perfect solid-liquid separation, and inflow of raw water exceeding the design capacity. It can quickly and perfectly cope with unexpected situations such as over power failure and mechanical failure, thus ensuring stable water quality at all times. In addition, the system according to the present invention can be ensured by the stable treatment water quality by the buffering action by the contact medium provided in the contact oxidation tank. Moreover, the system according to the present invention not only significantly reduces the initial facility cost by reducing the size of the reactor by reducing the residence time, but also minimizes the operation maintenance cost without causing the problem of secondary pollution. .

In the above described with reference to a preferred embodiment of the present invention, those skilled in the art various modifications and modifications of the present invention without departing from the spirit and scope of the present invention described in the utility model registration claims below It will be appreciated that it can be changed.

Claims (5)

In the advanced treatment system for removing organic matter, nitrogen and phosphorus, (a) an anaerobic bath equipped with a stirrer to denitrify the pretreated raw water; (b) an anaerobic tank in which the treated water flows from the anoxic tank and stores organic matter in the form of poly-β-hydroxybutyrate (PHB) in an anaerobic state and is equipped with a stirrer for inducing phosphorus release; (c) a contact oxidation tank equipped with a fixed bed contact medium and an aeration device for oxidizing the organic matter of raw water and ammonia nitrogen (NH ₄ ⁺ -N) induced by phosphorus in the anaerobic tank by microorganisms; (e) a membrane separation tank having an immersion type membrane and an aeration device for solid-liquid separation of the raw water treated from the contact oxidation tank into sludge-containing solid material and treated water; (g) a precipitation degassing tank for inducing precipitation while removing dissolved oxygen dissolved in the sludge-containing solid material separated in the membrane separation tank; And (f) means for returning the sludge-containing solid material from which dissolved oxygen has been removed from the settling degassing tank to an anoxic tank, The sedimentation degassing tank has an outer shape that gradually narrows down toward an inner side, and the treatment water outlet is provided at a point higher than the effective depth so that the excess amount of the solid-liquid separated treatment water can flow out by sedimentation. The advanced processing system according to claim 1, further comprising a sludge storage tank for storing sludge and a conveying device for transferring sludge-containing solid material from the sedimentation degassing tank to the sludge storage tank. The altitude processing system according to claim 1, wherein the aeration device is operated by at least one blower installed outside. The advanced treatment system of claim 1, further comprising a separate cleaning bath for cleaning the immersed membrane. 2. The advanced processing system of claim 1, wherein said anaerobic bath is two or more.