KR20030076547A - Treatment system and Method for Purifying Wastewater using Media Separator - Google Patents

Abstract

PURPOSE: Provided are a method and an apparatus for effectively and economically treating wastewater at low cost by removing organic material using biomedia and removing nitrogen and phosphorous by struvite (MgNH4PO4·6H2O) precipitation process. CONSTITUTION: The method comprises the steps of (a) adsorbing organic material to media having microorganism thereon under anaerobic condition, (b) causing struvite precipitation reaction for removing nitrogen and phosphorous by inputting pH adjusting agent and magnesium into the treated water of the step (a), (c) inputting the media used in the step (a) into the treated water of the step (b) and decomposing organic materials in the treated water and adsorbed to the media under aerobic condition, and (d) settling suspended solids in the treated water of the step (c) and microorganism sloughing from the media.

Description

Treatment system and method for treating wastewater using median separator {Treatment system and Method for Purifying Wastewater using Media Separator}

The present invention relates to a method for purifying wastewater using a media separator, and more particularly, to remove organic substances by using a media (media), which is a fluid carrier in which microorganisms adhere and grow, and struvite (MgNH ₄ PO). ₄ · 6H ₂ O) The present invention relates to a method for the purification of high concentration wastewater and its treatment apparatus that can be efficiently and economically operated by sequentially removing nitrogen and phosphorus by crystallization.

In general, nitrogen and phosphorus contained in sewage and waste water cause eutrophication of rivers, deplete dissolved oxygen and act as toxic to aquatic organisms such as fish and cause odors, making it difficult to use as a constant. When it was introduced into the sea, it was a cause of red tide, and in severe cases, it was decayed at the bottom of the water, causing odor and water pollution, which required the removal of nitrogen and phosphorus from sewage and wastewater.

Conventionally, a physicochemical purification method and a biological purification method have been used together to remove nitrogen and phosphorus contained in sewage or wastewater.

As a physicochemical purification method for treating nitrogen or phosphorus, which are representative nutrients, ammonia degassing, ion exchange using selective adsorption, and precipitation using chemicals such as Alum (coagulant) are used. However, the physicochemical treatment method has the advantage that the purification treatment is selective and rapid, while in order to remove all organic matter, nitrogen and phosphorus, excessive chemical cost is consumed and the amount of waste sludge generated is high, which requires a large treatment cost. There was a problem that it is difficult to expect stable treated water quality.

On the other hand, biological purification treatment method has been developed and widely applied, such as A / O, A ² / O, UCT, VIP and Bardenpho, and has the advantage of high stability of purified water quality and economical purification, but aerobic when removing nitrogen Since the nitrification required under the conditions and the denitrification required under the anoxic conditions must be performed, the aerobic and anaerobic requirements must be met. When the concentration of nitrogen is high, such as industrial wastewater, the purification time by microorganisms is very long. There was a problem that the investment burden of the initial equipment cost is large and the operating conditions for creating the environment necessary for the growth of microorganisms are difficult, requiring skill in operation.

For example, assuming that the concentration of nitrogen in the wastewater is 300 mg / L at pH 7 at a temperature of 20 degrees Celsius, the un-ionized ammonia nitrogen (free-ammonia) maintains 1.18 mg / L, which contributes to nitrification. Nitrobacter, which is a microorganism, is in the range of 0.1-1.0 mg / L reported to be inhibited, which is inhibited by growth, and the rate of nitrification is very slow. When nitrogen concentration in wastewater such as livestock wastewater is high, There was a problem that the biological purification of nitrogen is very difficult due to toxic damage.

Therefore, in recent years, the development of sewage and wastewater purification methods for simultaneously removing organic matter, nutrients such as nitrogen and phosphorus by combining physicochemical purification methods and biological purification methods has been continuously attempted.

The present invention has been made to solve the above problems, an object of the present invention is to combine the physicochemical wastewater purification treatment method and biological wastewater purification treatment method to quickly and organically contained in the sewage or wastewater, nitrogen and phosphorus To provide a waste water purification method and treatment device that can be stably and economically purified,

An object of the present invention is to remove organic matter from wastewater introduced by using a fluid carrier (Media) to which microorganisms adhere and grow, and to remove nitrogen and phosphorus by using struvite crystallization and to remove the remaining organic matter by using microorganisms again. It is to improve the processing efficiency.

1 is a process chart showing the wastewater purification method of the present invention.

2 is a schematic view of a wastewater treatment apparatus according to a first embodiment of the present invention.

3 is a schematic view of a wastewater treatment apparatus according to a second embodiment of the present invention.

4 is a schematic view of a wastewater treatment apparatus according to a third embodiment of the present invention.

5 is a schematic view of a wastewater treatment apparatus according to a fourth embodiment of the present invention.

6a and 6b are schematic views of a separator for separation of media and wastewater;

<Description of Symbols for Main Parts of Drawings>

1: anaerobic reactor 2: struvite crystallization tank

3: aerobic reactor 4: precipitation tank

5: intermittent aeration reactor 6: second intermittent aeration reactor

7: Separator 8: Struvite reservoir

9: mixed reactor 10: media

11: screen 100: organic matter adsorption step

200: struvite crystallization step 300: organic decomposition step

400: precipitation step

In order to achieve the above object, the present invention is a sewage or wastewater purification method containing organic matter, nitrogen and phosphorus, the influent wastewater is brought into anaerobic state by contacting the medium, which is a fluid carrier to which microorganisms are attached and grow. The organic material adsorption step (100) to induce the adsorption of organic matter; and the hydrogen ion concentration (pH) regulator and magnesium (Mg ⁺² ) in the inflow wastewater from which a certain amount of organic matter is adsorbed while passing through the organic material adsorption step (100) The struvite crystallization step (200) for removing nitrogen and phosphorus by injection; and the organic material adsorption step to the wastewater introduced by removing a certain amount of organic matter and nitrogen and phosphorus by passing through the struvite crystallization step (200) ( Organic material decomposition step 300 of transporting and mixing media with a certain amount of organic matter attached in 100) to induce decomposition such as organic matter remaining in an aerobic state; And a precipitation step 400 for precipitating and removing the suspended matter and some desorbed microorganisms contained in the purified water from which organic matter and nitrogen and phosphorus have been removed.

The organic material adsorption step 100 is a microorganism grown by using an organic material by mixing a certain amount of fluid carrier (Example: Linde brand name Linpor-12x12x15mm) into the anaerobic reaction tank (1) in which the inflow of air is blocked This is to provide a place where it can be attached and grow, and the organic matter contained in the introduced wastewater is absorbed or adsorbed by the microorganisms so that the concentration in the wastewater is lowered.

The degree of adsorption of organic matter, which indicates the concentration of organic matter in the wastewater, may vary slightly depending on the characteristics of the influent wastewater or the activity of the microorganisms, but when the age of the microorganism (age of the microorganism) is 14 and 25 days, The adsorption rate of organic matter was shown, in which the reaction time was 40 minutes.

At this time, the anaerobic reaction tank (1) is to form a suitable stirring device to maintain a state in which the influent wastewater and the media are sufficiently mixed to achieve a uniform contact to achieve homogenization of the organic concentration.

Waste water passing through the organic matter adsorption step (100) anaerobic reaction tank (1) is sent to the struvite crystallization tank (2), which is a struvite crystallization step (200) for removing nitrogen and phosphorus, and the media is formed in the pipeline. After being separated through a separation device (7) such as a screen and flows into the aerobic reaction tank (3), which is an organic decomposition step (300),

Wastewater flowed into the struvite crystallization tank 2 is injected with magnesium and a hydrogen ion concentration (pH) regulator such as sodium hydroxide (NaOH) so that struvite crystals can occur in an optimal state.

As is well known, the struvite crystal formed by combining Mg: NH ₄ : PO ₄ in a molar ratio of 1: 1: 1 has a high specific gravity, so that precipitation is rapid and the resulting precipitate can be used as a soil improver and fertilizer. It can be a useful substance.

At this time, the reaction time required for struvite crystallization is required within 2 minutes, and the struvite crystallization tank 2 under the struvite crystallization reactor 9 so that crystals can be recovered smoothly and a compacted purification device can be manufactured. It is preferable to form a, and the lower portion of the struvite crystallization tank (2) is to form an inclined surface or to form a suitable withdrawal device such as a valve or a solid transfer pump so that the precipitated struvite crystal can be easily recovered .

In particular, in the struvite crystallization tank 9, it is preferable to form a stirring apparatus so that the introduced wastewater, the injected hydrogen ion concentration regulator and magnesium can be sufficiently mixed.

Nitrogen and phosphorus removal efficiency of the wastewater that passed through the struvite crystallization step 200 was generally 80% or more.

According to the experiment, it was observed that 81 and 83% of nitrogen and 98% and 93% of phosphorus were removed using MgCl 2 and Mg (OH) 2 as magnesium sources. (Reference: Korean Society of Environmental Engineering, Vol 22 , No. 4, 2000.4, KOREA, Won-Seon Won et al., Removal of Nitrogen and Phosphorus by Struvite Crystallization, pp. 599-607). Tunay et al. (Ref .: Water Science and Technology, Vol. 36, No. 2-3, 1997, UK, O.Tunay, I. Kabdasli, D. Orhon and S. Kolcak, Ammonia removal by magnesium ammonium phosphate precipitation in industrial wastewater, pp.225-228) At pH 8.5, nitrogen and phosphorus showed 87% and 90.2% removal, respectively.

The wastewater passing through the struvite crystallization step 200 is introduced into the aerobic reaction tank 3, which is an organic decomposition step 300, and transferred to the anaerobic reaction tank 1, which is an organic adsorption step 100, with organic matter absorbed and adsorbed. Mixed with

At this time, according to the respiration of the microorganisms attached to the media, the decomposing action of organic matter absorbed and adsorbed and the organic matter remaining in the waste water occurs.

After a certain time has elapsed, the wastewater in which the decomposition of organic matter is completed is transferred to the settling tank 4, which is a precipitation step 400.

At this time, the media 10 in which all of the absorbed organic matter is decomposed is returned to the anaerobic reaction tank 1 performing the organic matter adsorption step 100 along the return pipe and mixed with the newly introduced wastewater.

The settling tank 4 is to separate the desorbed microorganisms or suspended matter and purified water so as to discharge the waste water and the generated sludge which has been purified.

At this time, some of the microorganisms precipitated in the settling tank (4) is returned to the anaerobic reaction tank (1) performing the organic material adsorption step 100, so that the microorganisms needed to purify the wastewater without newly injecting microorganisms are not deficient. You can do it.

Hereinafter, with reference to the accompanying drawings will be described in detail the most preferred embodiment of the present invention. First, in describing each of the drawings, only the same components have the same reference numerals as much as possible even if shown on different drawings.

2 is a schematic view showing an apparatus for treating wastewater according to a first embodiment of the present invention.

As shown, the wastewater treatment apparatus using the median separation apparatus of the present invention is anaerobic reactor (1) and the anaerobic reactor (1) is mixed with the wastewater in which the media (10), which is a fluid carrier to grow microorganisms attached The struvite is placed under the struvite crystallization reactor 9 and the struvite crystallization reactor 9, which is connected to the apparatus and comprises a hydrogen ion concentration (pH) regulator and a magnesium (Mg ⁺² ) injector. The struvite crystallization tank 2 in which crystal precipitation takes place, and the struvite storage tank 8 connected to the lower part of the struvite crystallization tank 2 and extracting and storing the struvite crystals, and the struvite crystals An aerobic reactor (3) in which the wastewater passed through the media (10) separated from the anaerobic reactor (1) through the separator (7) and passed through the struvite crystallization tank (2) is mixed; Is subsequent to the ready-made reaction tank (3) subjected to solid-liquid separation to induce the precipitation of the desorbed microorganisms and suspended, a block consisting of some microorganisms in the anaerobic settling tank (4) comprising a feed pipe for returning to the reaction tank (1).

At this time, the anaerobic reactor (1), the struvite crystallization reactor (9) and the aerobic reactor (3) forms a stirring device so that the influent wastewater, median, influent wastewater, hydrogen ion concentration regulator and magnesium (Mg ⁺² ) are completely At the bottom of the struvite crystallization tank (2) and the settling tank (4), an inclined surface is formed to collect precipitated struvite crystals or waste sludge, or a drawing device such as a valve or an inlet pump can be mixed. It can form.

In particular, in the anaerobic reactor 1 and the aerobic reactor 3 into which the media 10 are introduced, separators 7 and 11 for separating wastewater and media 10 are formed to prevent the media 10 from flowing out. The separation device (7) (11) can be formed by inserting a mesh (mesh) having a gap smaller than the standard of the media (10) to the branching position of the branch pipe, etc. This can be achieved in various ways.

On the other hand, the struvite crystallization tank 9 has a shorter reaction time than the entire purification time and its size is also small, so that the struvite crystallization tank 2 can be formed in the inner space of the struvite crystallization tank 2.

In the wastewater purification apparatus using the media separation apparatus of the present invention having the above configuration, nitrogen and phosphorus are removed in the struvite crystallization tank 2, and organic matter is removed in the aerobic reaction tank 3, and the organic matter contained in the wastewater. It will be able to remove nitrogen and phosphorus.

3 is a schematic view showing an apparatus for treating wastewater according to a second preferred embodiment of the present invention.

According to Figure 3, the wastewater treatment apparatus using the median separator of the present invention is anaerobic reactor (1) and the anaerobic reactor (1) is mixed with the wastewater in which the media (10), which is a fluid carrier to grow microorganisms attached The Struvite crystallization reactor (9) and the Struvitet crystallization reactor (9), which are connected to the tube and comprise a hydrogen ion concentration (pH) regulator and a magnesium (Mg ⁺² ) injector, A struvite storage tank 8 and a struvite storage tank 8 connected to a lower part of the struvite crystallization tank 2 in which precipitation of the bite crystals occur, and for extracting and storing the struvite crystals; The wastewater which passed through the crystallization tank 2 and passed through the medial 10 and the struvite crystallization tank 2 separated and discharged from the anaerobic reactor 1 through the separator 7 was mixed in a predetermined time distribution. And following the intermittent aeration reactor 5 and the intermittent aeration reactor 5 where the aeration is repeated to induce precipitation of suspended solids and desorbed microorganisms to perform solid-liquid separation, and to return some of the microorganisms to the anaerobic reactor 1. It is the structure which consists of the settling tank 4 containing a conveyance pipe.

The intermittent aeration reaction tank 5 may operate the aeration and non-aeration reaction time to 1 hour / 1 hour, 2 hours / 1 hour and 2 hours / 2 hours, respectively, according to the operating method. This method of operation is a method for removing low concentrations of effluent nitrogen and phosphorus removed from the sturubite crystallization tank (2) according to the waste water properties, for example 100 mg / L and 10 mg / Nitrogen and phosphorus are theoretically 10 mg / L and 1 mg / L are introduced into the intermittent aeration reactor (5), assuming 90% is removed from the struvite crystallization tank (2). And in order to maximize the removal of phosphorus nitrification and denitrification for nitrogen removal is required.

By nitrifying bacteria (Nitrosomonas & Nitrobacter) the ammonia nitrogen and organic nitrogen in aerobic conditions by microbial nitrification in the anoxic conditions by (deformation of ammonia to nitrate form) and denitrification bacteria to nitrate (Pseudomonas, Paracoccus Denitrifiers etc.) and to be used as an electron acceptor instead of oxygen converted to nitrogen gas will which can be removed by radiation (denitrification) into the atmosphere, which is to keep under an anaerobic condition and an aerobic condition to shift the waste water removed in the anaerobic conditions, micro-organisms (Acinetobacter) In the subsequent aerobic conditions, the phosphorus is removed from the wastewater in such a way that the microorganisms excessively ingest the phosphorus and then remove the microorganisms by a certain amount, thereby maximizing nitrogen and phosphorus removal efficiency.

4 is a schematic view showing an apparatus for treating wastewater according to a third embodiment of the present invention.

According to Figure 4, the wastewater treatment apparatus using the median separator of the present invention is anaerobic reactor (1) and the anaerobic reactor (1) is mixed with the wastewater in which the media (10), which is a fluid carrier to grow microorganisms attached The Struvite crystallization reactor (9) and the Struvitet crystallization reactor (9), which are connected to the tube and comprise a hydrogen ion concentration (pH) regulator and a magnesium (Mg ⁺² ) injector, The struvite crystallization tank 2 in which precipitation of a bite crystal occurs, and the struvite storage tank 8 connected to the lower part of the strutbyte crystallization tank 2 and extracting and storing the struvite crystals, and the strut byte The wastewater which passed through the crystallization tank 2 and passed through the medial 10 and the struvite crystallization tank 2 separated and discharged from the anaerobic reactor 1 through the separator 7 was mixed in a predetermined time distribution. And the aerobic reactor 5 followed by the non-aeration, the aerobic reactor 3 subsequent to the intermittent aerobic reactor 5 and the aerobic reactor 3 followed by induction of precipitation of suspended solids and desorbed microorganisms to solid-liquid separation. And a settling tank 4 including a conveying pipe for conveying some microorganisms to the anaerobic reaction tank 1.

The aerobic reactor 2 has an effect of increasing the stability of the purified water quality.

FIG. 5 is a schematic view showing an apparatus for treating wastewater according to a fourth preferred embodiment of the present invention. According to the drawings, FIG. 5 is the same as the third embodiment shown in FIG. 4, but only a plurality of intermittent aeration reactors 5 and 6 are provided. It is a configuration provided with.

At this time, the intermittent aeration reactor (5) (6) divided into a plurality of the first intermittent aeration reactor (5) is operated by aeration, the second intermittent aeration reactor (6) to operate the aeration and non-aeration with each other in a non-aeration It will be able to maximize the removal rate of nitrogen and phosphorus.

The present invention removes nitrogen and phosphorus from wastewater by using the struvite crystallization method, and removes organic matter by using adherent growth microorganisms of media, and can simultaneously remove organic matter, nitrogen and phosphorus, and use of adherent microorganisms. The effect is to reduce the amount of sludge generated.

Wastewater purification method and treatment apparatus according to the present invention is capable of purifying nitrogen and phosphorus that cause eutrophication, and wastewater capable of producing high purity struvite when struvite crystallizes by adsorption of organic matter from influent wastewater. High purity struvite, which has been crystallized as a purification method and apparatus, can be used as a fertilizer or soil improving agent.

In addition, since the present invention uses adherent growth microorganisms, the amount of sludge generated can be reduced compared to the floating purification method, and the advantages of the chemical purification method that is rapidly purified and the biological purification that can be expected of stable purified water quality are combined. The process has the advantage of being widely used in high concentration industrial wastewater and livestock wastewater.

Claims (5)

In the sewage or wastewater purification method containing organic matter, nitrogen and phosphorus, organic matter adsorption for inducing the adsorption of organic matter in anaerobic state by contacting the introduced wastewater with the medium, which is a fluid carrier that grows with microorganisms. Step 100 and the organic material adsorption step (100) and the hydrogen ions concentration (pH) regulator and magnesium (Mg ⁺² ) is injected into the influent wastewater from which a certain amount of organic matter is adsorbed and removed to remove nitrogen and phosphorus The struvite crystallization step (200); and the struvite crystallization step (200) is a certain amount of organic matter and nitrogen and phosphorus is removed by the organic matter adsorbed in the organic material adsorption step (100) attached to the wastewater is introduced Organic material decomposition step 300 of transferring the media to induce decomposition such as organic matter remaining in an aerobic (好 氣 性) state; And a precipitation step (400) for sedimenting and removing suspended solids and some desorbed microorganisms contained in the purified water from which organic matter, nitrogen and phosphorus have been removed. The anaerobic reactor (1) and the anaerobic reactor (1), which are mixed with the wastewater in which the media (10), which is a fluid carrier that grows with microorganisms, are mixed, are connected to the anaerobic reactor (1), and a hydrogen ion concentration (pH) regulator and magnesium (Mg ^+2). ) The struvite crystallization tank 9 including the injection device, and the struvite crystallization tank 2 and the struvbite located below the struvite crystallization reactor 9, where precipitation of the struvite crystals occurs. A device 7 connected to the lower part of the crystallization tank 2 and subsequent to the struvite crystallization tank 2 and a struvite storage tank 8 for extracting and storing the struvite crystals from the anaerobic reactor 1 Followed by the aerobic reactor (3) and the aerobic reactor (3) in which the wastewater passed through the media (10) and the struvite crystallization tank (2) separated and discharged through induction to induce precipitation of suspended matter and desorbed microorganisms Go To perform, in the waste water purification system using a media-separating device, characterized by the configured portion of the microorganisms in the anaerobic settling tank (4) comprising a feed pipe for returning to the reaction tank (1) separation. The apparatus for purifying wastewater using a median separator according to claim 2, wherein the aerobic reactor (3) is operated as an intermittent aeration reactor (5) in which aeration and non-aeration are repeated according to a predetermined time distribution. 3. The apparatus for purifying wastewater using a median separator according to claim 2, wherein at least one intermittent aeration reactor (5) (6) is further provided in front of said aerobic reactor (3). The aerobic / intermittent aeration reactor (3) / (5) / (6) located at the front end of the settling tank (4) is further provided with a separator (7). Wastewater purification device using a media separator.