KR101544604B1

KR101544604B1 - SYSTEM FOR RECYClYING DISCHARGE WATER OF SEWAGE TREATMENT PLANT

Info

Publication number: KR101544604B1
Application number: KR1020150040697A
Authority: KR
Inventors: 김인식
Original assignee: 신진유지건설 주식회사
Priority date: 2015-03-24
Filing date: 2015-03-24
Publication date: 2015-08-18

Abstract

The present invention relates to a system for recycling effluent of a sewage treatment plant, and more particularly, to a system for recycling effluent discharged from a sewage treatment plant. More particularly, the present invention relates to a system for reusing effluent discharged from a sewage treatment plant, To a system for reusing effluent discharged from a sewage treatment plant which can reuse discharged water as industrial water.
According to the present invention, it is possible to enhance the efficiency of solid-liquid separation of flocculated sludge, and to improve the recyclability of effluent water of a sewage treatment plant which has enhanced recyclability of industrial waterway.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for recycling wastewater discharged from a sewage treatment plant,

The present invention relates to a system for recycling effluent of a sewage treatment plant, and more particularly, to a system for recycling effluent discharged from a sewage treatment plant. More particularly, the present invention relates to a system for reusing effluent discharged from a sewage treatment plant, To a system for reusing effluent discharged from a sewage treatment plant which can reuse discharged water as industrial water.

In general, phosphorus (phosphoric acid), which is the main cause of eutrophication and is a limiting factor for algal growth, has been mainly treated by biological treatment methods and chemical treatment methods using coagulants in the total phosphorus treatment apparatus of sewage and wastewater treatment plants.

However, biological processes are difficult to operate, and it is not easy to obtain sustained and stable effluent quality.

Another electrolytic / flocculent phosphorus removal technology is one of the technologies that can take advantage of the chemical removal technology and solve the disadvantages of the chemical precipitation method, but it has problems such as electrode corrosion. The reuse of shell is used for removing exhaust gas, improving agent of acid soil, adsorption of heavy metals, high concentration of phosphorus, etc. However, calcium carbonate, which accounts for most of the oyster shell, has a large amount of sludge generated in water treatment, There is a problem that an appropriate firing process is required due to a problem.

In addition, the crystallization dephosphorization method is one of physico-chemical treatment methods that have been put to practical use among methods of removing phosphorus in sewage, and it is possible to treat ordinary sewage secondary treatment water. However, Other forms of phosphorus (polyphosphoric acid, organophosphorus, suspended solids), such as pH, calcium concentration, water temperature, disturbances in raw water, contact time, performance of the contact material, It should be removed by secondary functions such as filtration.

In the assembly and dismantling method, magnesium is added to sewage to regulate the pH, thereby recovering phosphorus as a crystal of magnesium ammonium phosphate (MAP), but it is not suitable for treating discharged water.

In particular, the biological removal processes of anaerobic and aerobic bacteria, which are widely used, are converted into polyphosphoric acid, which is an intracellular substance of phosphorus microorganisms, and organic materials such as volatile fatty acids and carbon sources must be supplied. It is not economic and difficult to improve the biological phosphorus and nitrogen simultaneous process because it competes with the carbon source organic matter such as methanol which is required for nitrogen removal.

In addition, conventional physical and chemical treatment apparatuses have difficulties in overuse of chemicals and disposal of sludge treatment.

One of the measures for solving the problems of the above-mentioned prior art is disclosed in Korean Patent No. 10, entitled " Filtration and Adsorption Multistage Wastewater Treatment Apparatus for Removing Total Entrainment of Wastewater Treatment Plant Wastewater, " issued Jun. 27, -2007-0063413 filed on Oct. 2, 2008, which is hereby incorporated by reference in its entirety.

FIG. 1A is a view showing the entire construction of a filtration / adsorption multi-stage wastewater treatment apparatus for removing total phosphorus from discharged water in a sewage treatment plant according to the prior art. FIG. 1B is a cross- Fig. 7 is a view showing an adsorption device section. Fig.

Referring to FIGS. 1A and 1B, a filtration and adsorption multistage treatment apparatus for removing total phosphorus from discharged water in a sewage treatment plant according to the prior art is characterized in that the discharged water from a sewage treatment plant is treated through a multistage tank.

More specifically, in the filtration / adsorption multistage treatment apparatus for removing the total phosphorus of the discharged water in the sewage treatment plant according to the prior art, the discharged water is discharged from the secondary sedimentation tank, flows into the flow rate control unit 10, And is supplied to the pre-filtration unit 20 constituted of filter media. If the residence time is to be adjusted according to the flow rate, the suspended substance and the total phosphorus of the introduced effluent, the flow rate regulator 10 is required. The inflow water flows into the lower end of the pre-filtration unit 20, passes through the lower end and upper end of the pre-filtration unit 20, and then flows into the filtration and absorption unit 30. Here, the filtration and adsorption apparatuses for treating the effluent of the sewage treatment plant are composed of two stages of filter media inside the apparatus. The front filtration unit 20 is filtered by a polyurethane based synthetic resin filter medium and the filtration and absorption unit 30 at the downstream is operated in an upward flow by using an adsorbent having a particle size of about 0.7 mm. In addition, when used as a tertiary treatment of a sewage treatment plant, it flows into the disinfecting tank 50 to disinfect pathogenic bacteria such as Escherichia coli.

As described above, in the filtration / adsorption multi-stage wastewater treatment apparatus for removing the total phosphorus of the discharged water of the sewage treatment plant according to the prior art, it is possible to perform the suspension filtration of the discharged water through the two-stage filtration treatment apparatus.

However, in the filtration and adsorption multi-stage wastewater treatment apparatus for removing the total amount of the discharged water from the sewage treatment plant according to the above-described prior art shown in Figs. 1A and 1B, the total phosphorus is considerably removed through the filter material installed in two stages, The amount of total phosphorus is about 1 mg / L, and the time required for the removal of the phosphorus is considerably long.

FIG. 1C is a view showing a result of removing the total phosphorus from an experimental apparatus for filtration treatment of a filtration / adsorption multi-stage wastewater treatment apparatus for removing total phosphorus from discharged water in a sewage treatment plant according to the prior art.

Referring to FIG. 1C, in the prior art, the concentration of total phosphorus in the incoming effluent is maintained at approximately 2.7 to 4.2 mg / L (approximately 3 mg / L) for approximately 30 days and the amount of residual phosphorus after total phosphorus removal is approximately 0.8 To 1.2 mg / L (approximately 1 mg / L on average).

The effluent having a total phosphorus of about 1 mg / L is sufficient for reuse, for example in industrial water, but it takes about 30 days to maintain a total phosphorus of about 1 mg / L, It is achieved after about 40 days in order to maintain a total phosphorus of about 0.3 mg / L.

As described above, in the prior art, since the time required to remove the total phosphorus by a very small amount (approximately 1 mg / L on average) is very long, the amount of the phosphorus adsorbent to be used increases considerably, Ultimately, there is a problem that there is no economical efficiency.

Also, according to the Enforcement Regulations of the Sewer Law of the Republic of Korea, which was revised and promulgated on February 26, 2010, water quality standards for total water in discharged water have been drastically increased from 2 mg / L to 0.2 mg / L in 2012 to improve river water quality. Accordingly, there arises a problem that the conventional technology does not satisfy the new water quality standard of the total person in the discharged water.

Therefore, not only the total phosphorus and dissolved organic substances in the discharged water can be quickly removed to a trace amount or less, for example, it can be reused as industrial water, and it is also maintained as a new water quality standard of TP of 0.2 mg / L or less A new approach is required.

For this purpose, Patent No. 1026734 is disclosed.

However, in this case, cohesion is weak, solid-liquid separation of coagulated sludge is not smooth, and it becomes a factor to hinder the recyclability of industrial water due to the inflow of foreign matter during treatment of discharged water.

Korea Patent Registration No. 10-0861554 (Oct. 2, 2008) "Filtration and adsorption multi-stage wastewater treatment device for removing total phosphorus from sewage treatment plant effluent water" Korean Patent Registration No. 10-1026734 (Mar. 28, 2011) "Treatment Apparatus and Method for Reuse of Effluent Water"

The present invention has been made in view of the above-described problems in the prior art, and provides a system for recycling waste water from a sewage treatment plant, It has its main purpose.

As a means for achieving the above object, the present invention provides a system for recycling waste water from a sewage treatment plant, comprising: A flocculation reaction tank into which effluent water is introduced, a flocculant is injected therein, and flocculation reaction treatment is performed with the effluent water; A neutralization tank in which the flocculation reaction treated flocculation reaction water is introduced and a neutralization agent is injected to perform a neutralization reaction treatment; A flocculation tank into which the neutralization-treated neutralized water flows and into which a coagulation aid flows to form a floc; A sedimentation tank through which the flocculated sludge is transferred from the flocculation sludge tank, the flocculation sludge in the fl uid forming water is separated and discharged, and the treated sludge is removed; An ozone contact tank that removes a small amount of total phosphorus and dissolved organic matter remaining in the treated water into which ozone is injected to treat odor, color, turbidity, heavy metals, and E. coli to generate reused water; And a nano bubble generating unit that is connected to the flocculation tank, the neutralization tank, the flocculation tank, and the ozone contact tank and generates nano bubbles respectively in the flocculation tank, the neutralization tank, Generating device; A flocculant reservoir for storing the flocculant; A first metering pump for introducing the flocculant into the flocculation tank from the flocculant reservoir; A neutralizer reservoir for storing the neutralizer; A second metering pump for introducing the neutralizing agent from the neutralizing agent storage tank into the neutralization tank; A flocculation assistant reservoir for storing the flocculant aid; And a third metering pump for introducing the coagulation aid from the coagulation aid reservoir into the bath; A first agitator for mixing the effluent and the flocculant in the flocculation tank; A second agitator for mixing the flocculated effluent and the neutralizing agent in the neutralization tank; And a third agitator for mixing said neutralization water and said flocculation aid in said flocking tank; The treated water discharged through the discharge end of the ozone contact tank is stored in the reused water storage tank, and the discharge end of the reused water storage tank is connected to the upper portion of the heating tank; The heating tank is provided with a drain guide at an upper end portion thereof to guide the drain water drained through the drain end to one direction to smoothly flow into the heat chamber; Wherein the heat chamber is a rectangular box-shaped chamber sealed inside, the burner being installed to pass through one side of the heat chamber to heat the inside of the heat chamber to a high temperature of 300-400 DEG C; A plurality of discharge water pipes for heat exchange are arranged in a zigzag form in the heat chamber so that the discharged water guided through the water drain guide is indirectly heated while exchanging heat with high temperature heat supplied from the burner while being perfused; The heat exchanged effluent is configured to be discharged to the top of the heat chamber; A supply pipe is connected to discharge waste water collected in the lower portion of the heating tank after being discharged to the upper portion of the heat chamber to the decomposition filtration tank; The decomposition filtration tank is a cylindrical member having a funnel shape at its lower end and a pair of spray nozzles at its upper end; The spray nozzle is connected to a microbial mixed water pipe, which is connected to a water tank at an end of the microbial mixed water pipe; Wherein the water tank is provided with a water pump to pump water; The aerobic microorganism tank is connected to a part of the length of the microorganism mixed water pipe, the aerobic microorganism tank is adjusted so that only a certain amount of the aerobic microorganism can be accurately supplied through the quantitative control valve; Wherein said decomposing and filtering tank has a double structure built therein; The first and second filter nets are provided in multiple stages in the treatment tank; The effluent water supplied through the supply pipe is sequentially passed through the first and second filter nets and stored in the bottom of the treatment tank; Wherein a discharge hole is formed in a part of the periphery of the treatment tank so that water is discharged through the discharge hole in an overflow form; Wherein the overflowed effluent is discharged through a transfer tube to a stirred agitation tank; Wherein the agitation agitating tank is provided with a stirring motor on an upper surface thereof; A stirring blade is fixed to the motor shaft of the stirring motor; The decomposed effluent water is drained into the filtration tank through the effluent treatment line; The filtration water collecting tank is configured to filter out all foreign substances of 0.2 mm or more except for water through the first, second and third screens arranged in multi-stages; The filtered foreign substances are discharged through the first, second and third discharge trays; And the filtered effluent water is collected in a filtration water collecting tank.

According to the present invention, it is possible to enhance the efficiency of solid-liquid separation of flocculated sludge, and to improve the recyclability of effluent water of a sewage treatment plant which has enhanced recyclability of industrial waterway.

FIG. 1A is a view showing an overall configuration of a filtration / adsorption multi-stage wastewater treatment apparatus for removing total phosphorus from discharged water of a sewage treatment plant according to the prior art.
1B is a view showing a pre-filtration unit and a filtration and absorption unit of a filtration apparatus according to the prior art.
FIG. 1C is a view showing a result of removing the total phosphorus from an experimental apparatus for filtration treatment of a filtration / adsorption multi-stage wastewater treatment apparatus for removing total phosphorus from discharged water in a sewage treatment plant according to the prior art.
2 is a schematic view of a processing apparatus for reusing discharged water according to an embodiment of the present invention.
FIG. 3 is a graph showing data showing the results of the gun removal test using the processing apparatus for reusing the discharged water according to the present invention shown in FIG.
Figure 4 shows a further embodiment according to the invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Before describing the present invention, the following specific structural or functional descriptions are merely illustrative for the purpose of describing an embodiment according to the concept of the present invention, and embodiments according to the concept of the present invention may be embodied in various forms, And should not be construed as limited to the embodiments described herein.

In addition, since the embodiments according to the concept of the present invention can make various changes and have various forms, specific embodiments are illustrated in the drawings and described in detail herein. However, it should be understood that the embodiments according to the concept of the present invention are not intended to limit the present invention to specific modes of operation, but include all modifications, equivalents and alternatives falling within the spirit and scope of the present invention.

The present invention uses the above-described prior-art patent No. 1026734 as it is. Therefore, the features of the device configuration described below are all described in Patent Registration No. 1026734.

However, the present invention is characterized in that the additional embodiment portion in which the specific configuration is partially improved in order to achieve the object of the configuration disclosed in the above-mentioned Japanese Patent No. 1026734 is the most essential configuration feature.

Therefore, the device configuration, characteristics and operation relationship described below will be referred to as the contents of the above-mentioned Japanese Patent No. 1026734, and the configuration related to the main features of the present invention will be described in detail at the rear end.

Referring to FIG. 2, a treatment apparatus 200 for reusing effluent water according to an embodiment of the present invention includes a flocculation reaction tank 40 into which effluent water is introduced, in which a flocculant is injected and flocculation reaction treatment is performed with the effluent water; A neutralization tank 41 into which the coagulation reaction-treated flocculation reaction water is introduced, a neutralization agent is injected and neutralization reaction is performed; A flocculation tank 42 into which the neutralization-treated neutralized water is introduced and into which a coagulation aid flows to form a flock; A sedimentation tank 60 for discharging the treated water from which the flocculated sludge is transferred from the flocculation tank 42, the flocculated sludge in the fl uid forming water is separated from the flocculated sludge by liquid-liquid separation, and the coagulated sludge is removed; An ozone contact tank 70 for removing trace amounts of total phosphorus and dissolved organic substances remaining in the treated water after ozone is introduced and treating odors, color, turbidity, heavy metals, and coliform bacteria to produce reused water; And an ozone contact tank 70 connected to the flocculation tank 40, the neutralization tank 41, the flocculation tank 42 and the ozone contact tank 70. The flocculation tank 40, the neutralization tank 41, And a nano bubble generator 50 for generating nano bubbles in the ozone contact tank 70, respectively.

In addition, the treatment apparatus 200 for reusing effluent according to an embodiment of the present invention includes a flocculant reservoir 30 for storing the flocculant; A first metering pump (31) for introducing the coagulant from the coagulant reservoir (30) into the coagulation bath (40); A neutralizer reservoir (32) for storing the neutralizer; A second metering pump 33 for introducing the neutralizing agent from the neutralizing agent storage tank 32 into the neutralization tank 41; A flocculation aid storage tank (34) for storing the flocculation aid; And a third metering pump 35 for introducing the coagulation assistant from the coagulation assistant reservoir 34 into the flocking tank 42.

In addition, the treatment apparatus 200 for reusing effluent water according to an embodiment of the present invention includes a first agitator 21 for mixing the effluent and the flocculant in the flocculation tank 40; A second agitator (22) for mixing the neutralization agent with the flocculation reaction water in the neutralization tank (41); And a third agitator (23) for mixing and reacting the neutralization water and the coagulation assistant in the flocking tank (42).

The processing device 200 for reusing effluent water according to an embodiment of the present invention may further include the first to third metering pumps 31, 33 and 35, the nano bubble generator 50, And may further include a controller (controller) 20 for controlling the operation of the device 71. Here, the control device 20 may be implemented as a microprocessor or a programmable logic circuit (PLC) or the like.

Hereinafter, the specific configuration and operation of the processing apparatus 200 for reusing the discharged water according to an embodiment of the present invention will be described in detail.

Referring back to FIG. 2, first, effluent water that is biologically treated and discharged at a sewage and wastewater treatment plant flows into the storage tank 10. Thereafter, the effluent water flows into the coagulation bath 40 constantly in accordance with the current signal of the flow meter (not shown) of the inflow pump 11. At this time, the flocculant is introduced into the flocculation tank (40) by the first metering pump (31) from the flocculant storage tank (30) storing the flocculant such as iron chloride. The first metering pump 31 automatically injects the flocculant into the flocculation tank 40 in proportion to the flow rate and concentration of the influent water. In the flocculation tank (40), the effluent and the flocculant are mixed by the first stirrer (21) to cause flocculation reaction.

Thereafter, the coagulation reaction water in the coagulation reaction tank (40) is introduced into the neutralization tank (41). At this time, the neutralizing agent is introduced into the neutralization tank 41 by the second metering pump 33 from the neutralizing agent storage tank 32 for storing the neutralizing agent for adjusting the pH and the sedimentation efficiency. The second dosing pump 33 is operated in accordance with the flow rate and concentration of the flocculation reaction water which is the flocculation-treated water through the PH measurement control device (PHIC) and the redox electrode device (ORP) The neutralizing agent is automatically injected into the neutralization tank 41 in a proportional control manner. In the neutralization tank (41), the flocculation reaction water and the neutralizing agent are mixed by the second agitator (22) to perform the neutralization reaction, and the pH of the flocculation reaction water is adjusted.

Thereafter, neutralized water neutralized in the neutralization tank 41 flows into the flask forming tank 42. At this time, in order to increase the flocculation effect of the neutralized compound to increase the sedimentation effect, a coagulation assistant storage tank 34 for storing an aggregation aid such as a polymer flocculant is provided in the flocculation tank 42). The third dosing pump 35 automatically injects the coagulation assistant into the flocking tank 42 proportionally in proportion to the flow rate and concentration of the neutralized water, which is neutralized reacted water. In the flask forming tank 42, the neutralized water and the coagulation assistant are mixed by the third agitator 23 to form a flock.

In the present invention, when the effluent water is treated in the flocculation tank 40, the neutralization tank 41 and the flocculation tank 42, the flocculation tank 40, the neutralization tank 41, 42 are connected to each other to generate nano bubbles. The nano bubbles generated in the nano bubble generator 50 are subjected to the coagulation reaction process in the coagulation reaction tank 40, the neutralization reaction process in the neutralization tank 41, (TP) and trace amounts of dissolved organic matter during formation. Thereafter, the flocculated water flowing in the flocculation tank 42 is sent to the settling tank 60, and in the settling tank 60, the flocculated sludge is liquid-liquid separated by the sludge transfer pump 61 connected to the settling tank 60 And then discharged to a sludge concentration treatment apparatus (not shown).

Thereafter, the treated water from which the aggregated sludge has been removed in the sedimentation tank (60) flows into the ozone contact tank (70). At this time, the nano bubbles generated in the nano bubble generator 50 and the ozone generated in the ozone generator 71 are put into the ozone contact tank 70 together.

The nano bubbles introduced into the ozone contact tank 70 and the minute amounts of total phosphorus and dissolved organic matter remaining in the treated water which is equal to the ozone are removed and the reusing water generated by treating the odor, And flows into the water storage tank 72.

The mechanism according to odor, color, turbidity, heavy metal and coliform treatment in the ozone contact tank 70 is as follows.

- Deodorizing

The odor of the discharged water is odorous due to the mercaptan compound of the hydrocarbon and the sulfur component, and can be treated with dissolved ozone at 2 to 6 mg / L. The reaction formula is as follows.

_{nCxHySz + O 3 -> nCO 2} + nzSO 2 + nyH 2 O

- Color processing

The chromaticity of the effluent water is chromatic due to a very small amount of organic hydrocarbon double bonds, and it can be treated with dissolved ozone at 2 to 4 mg / L. The reaction formula is as follows.

_{(CxHy = CxHy) + O 3} -> nCO 2 + mH 2 O

- turbidity treatment

Turbidity of effluent water is evidenced by trace organic or inorganic hydrocarbons, wash outs of microorganisms, colloid particles and chromaticity, by the combination of chemical oxidation of free radicals such as OH ^- by dissolved ozone and neutralization of charge And the colloidal particles are enhanced in transparency by neutralizing the negatively charged particles by ozone.

- heavy metal treatment

Trace amounts of heavy metal ions in the effluent may be present in an insoluble form. Iron ions in the Fe ²⁺ state form Fe (OH) ₃ ions in the form of flocculent in the water and become pinkish. The reaction formula is as follows.

Fe ²⁺ + O ₃ + H ₂ O -> Fe ³⁺ + O ₂ + 2OH ^-

Fe ³⁺ + 3H ₂ O -> Fe (OH) ₃ + 3H ⁺

In addition, the soluble salts of manganese are oxidized to manganese dioxide (MnO ₂ ), which is insoluble in water. The reaction formula is as follows.

Mn ²⁺ + O ₃ + H ₂ O -> Mn ⁴⁺ + O ₂ + 2OH ^-

Mn ⁴⁺ + 4H ₂ 0 -> Mn (OH) ₄ + MnO ₂ + 2H ₂ O

- Escherichia coli treatment

E. coli treatment (or sterilization mechanism) is to oxidize organic molecules of the E. coli organism using ozone. More specifically, free radicals such as OH ^{- of} ozone oxidize sulfuric acid in coliform plasmids and chemically decompose the double bond of fatty acids in the cell wall and plasma membrane to ultimately degrade and sterilize the protoplasts.

As described above, in the ozone contact tank 70, a small amount of total phosphorus and dissolved organic matter remaining in the effluent water due to the nano bubbles and ozone is removed, and the odor, chromaticity, turbidity, heavy metals, , Reused water) is transferred into the reused water storage tank 72 and temporarily stored. Thereafter, the reused water is reused by, for example, industrial water depending on the application by the transfer pump 73 connected to the reused water storage tank 72.

The operations of the above-described inflow pump 11, the first to third metering pumps 31, 33 and 35, the nano bubble generator 50 and the ozone generator 71 are controlled by the controller 20 . In this case, the control device 20 automatically controls the first to third dosing pumps 31, 33, 35 in proportional control mode in which the flow rate and the concentration of the discharged water in the existing sewage and wastewater treatment plants are injected proportionally, The neutralizing agent and the coagulation assistant can be automatically injected into the flocculation tank 40, the neutralization tank 41, and the flocculation tank 42, respectively.

In the treatment apparatus 200 for reusing effluent water according to the present invention, the nano bubbles generated by the nano bubble generator 50 are supplied to the flocculation tank 40, the neutralization tank 41, Turbidity and chromaticity remaining in the treated water together with the ozone in the ozone contact tank 70 in the treatment of the total phosphorus and trace organic matter of the discharged water in the ozone contact tank 42 And it is used to increase the efficiency of the reaction by reducing the injection amount of ozone.

The nano bubbles generated by the nano bubble generator 50 are generated by physical stimulation (compression, expansion, vortex, etc.) caused by the flow of water, which occurs during the process of rapidly adiabatically compressing and expanding the air in the air The reaction takes place under extreme reaction of ultra-high pressure and ultra-high temperature. Nano bubbles generated by the extreme reaction of ultrahigh pressure and ultrahigh temperature decompose water molecules to form free radicals such as OH ^- . Since free radicals have very strong oxidizing ability, it is possible to decompose harmful organic substances and inorganic substances which are difficult to decompose, and thus it is possible to increase the efficiency of oxidation reaction. Such a nano bubble generator 50 is applied, for example, in Korean Patent No. 10-2008-0047863 entitled " Method and apparatus for treating wastewater using nano bubbles "issued May 23, 2008 (Hereinafter referred to as " 352 patent ") published on Dec. 2, 2008, the disclosure of which is incorporated herein by reference in its entirety.

The nano bubbles generated in the above-described 352 patented nano bubble generator have a diameter of 0.1 to 1 탆 (i.e., 100 to 1,000 nm). However, the inventors of the present invention have confirmed that it is preferable to increase the diameter of nano-bubbles and shorten the life of the nano-bubbles and to produce nano-bubbles having small diameters. Therefore, the nano bubbles generated in the nano bubble generator 50 according to the present invention are controlled to have a diameter in the range of approximately 100 to 200 nm. The nano bubbles having a diameter of about 100 to 200 nm have been found to stably exist in the effluent for a relatively long period of time, thereby enhancing the flocculating effect while reacting with phosphoric acid and phosphorus compounds, harmful organic matters and inorganic matters. When the diameter of the nano bubbles is reduced, ions that have been enriched at the time of nano bubbles are wrapped around the nano bubbles to prevent scattering of gases in the nano bubbles, thereby contributing to the stabilization of the nano bubbles (that is, . When the lifetime of nanobubbles is extended (that is, when the diameter of nanobubbles is reduced), the number of nanobubbles increases with respect to the same volume, and the surface area of the total nanobubbles and contaminated sewage and wastewater increases, . As a result, the pressurization of the gas gas (air or air and contaminated organic substances in the gaseous state) in the nano-bubbles continues for a longer time to dissolve gaseous and liquid organic pollutants, It is possible to achieve high efficiency also in the process process such as cultivation of microorganisms in the process of wastewater treatment. Therefore, in the present invention, by using the surface adhesion effect of the nano bubbles, the foam separation (forming nano bubbles and organic matters to form a scum shape) reduces phosphoric acid and phosphorus compounds and dissolved organic substances in the effluent to a very small amount Lt; / RTI >

FIG. 3 is a graph showing data showing the result of the total phosphorus removal test using the treatment device for reusing the effluent water according to the present invention.

Referring to FIG. 3, inflow water (i.e., effluent from existing sewage and wastewater treatment plants) is inflowed for 7 days from September 2, 2010 to September 8, 2010, and is discharged from 10:00 am to 5:00 pm on a regular basis (The discharged water discharged from the settling tank 60 shown in FIG. 2) and the final treated water (the discharged water discharged from the ozone contact tank 70 shown in FIG. 2 (that is, the reused water) (TP) of the total phosphorus (TP) in the sample.

As can be seen in Figure 3, the total amount of influent water was 2.35 mg / L on average. The total amount of total phosphorus in the intermediate treatment water measured 8 times daily was maintained at 0.3 mg / L or less with an average of 0.22 1 mg / L (mean minimum 0.14 mg / L and average maximum 0.35 mg / L) The amounts were maintained at less than 0.2 mg / L with an average of 0.11 mg / L (mean minimum 0.04 mg / L and mean maximum 0.19 mg / L). In addition, the total amount of total phosphorus in the intermediate treatment water did not exceed 0.4 mg / L and the maximum amount of total phosphorus in the final treatment water did not exceed 0.2 mg / L.

As described above, in the present invention, the residual amount of total phosphorus was maintained at a maximum of 0.4 mg / L or less while maintaining an average of 0.22 mg / L for the intermediate treated water within about 1 to 2 hours after the inflow of the influent water, Maintaining a maximum of 0.2 mg / L or less, while maintaining an average of 0.11 mg / L, quickly removes total phosphorus in a much shorter time than in the prior art, resulting in a significant reduction in the use of flocculants, neutralizers, and flocculants. Accordingly, the cost for removing the gun is greatly reduced, so that the present invention can be sufficiently economical.

Further, in the present invention, an advantage that the total amount of the final treated water (that is, the reused water) has a significantly lower value than that of the prior art, so that the total removal can be made very efficiently.

As described above, the nano bubbles generated by the nano bubble generator 50 according to the present invention increase the oxidation reaction and surface area of OH ^- , quickly react the reaction time of the organic pollutant, the coagulating agent and the ozone in a short time, The phosphorus and phosphorus compounds in the effluent water and a small amount of soluble organic matter are treated and the nano bubbles and a small amount of ozone are put into the ozone contact tank 70 at the subsequent stage together as described above to adjust the chromaticity, The amount of total phosphorus can be reduced to a value of about 0.2 mg / L or less such that final discharge water can be reused as industrial water or the like.

In addition, a further embodiment according to the present invention connects the discharge end (DR) of the reusing water storage tank (72) to the upper part of the heating tank (100) as shown in Fig.

At this time, the heating tank 100 is provided with a drainage guide 110 at an upper end portion thereof, so that the drainage water drained through the drainage DR is guided to one side in a smooth manner so as to flow smoothly into the heat chamber 120.

The heat chamber 120 is a rectangular box-shaped chamber sealed inside. The heat chamber 120 is provided with a burner 130 through one side thereof to heat the inside of the heat chamber 120 to a high temperature of about 300-400 ° C. .

A plurality of discharge water pipes 140 for heat exchange are arranged in a zigzag form in the heat chamber 120. The heat pipes 140 are arranged through a space arrangement so that the heat of the burner 130 is not directly received, A heat plate or the like may be attached to the adjacent position.

In this case, the most important concept is that the discharge water pipe 140 should be arranged so as to be flush with the drainage guide 110. By doing so, the heat exchange efficiency can be maximized.

The heated effluent water is subjected to a high-temperature pyrolysis process together with the foreign substances and is discharged to the upper part of the heat chamber 120 and then collected in the lower part of the heating tank 100. The discharged water is then conveyed to the decomposition filtration tank 200 .

The decomposition filtration tank 200 is a cylindrical member having a funnel shape at the bottom and a pair of spray nozzles 210 are installed at an upper end of the decomposition filtration tank 200. The spray nozzle 210 is connected to the microbial mixed water pipe 220 The end of the microorganism mixed water pipe 220 is connected to the water tank 230 and is configured to be supplied with water by the water pump 230. The tank 240 is connected.

At this time, the aerobic microorganism tank 240 should be adjusted so that only a certain amount of aerobic microorganisms can be accurately supplied through the quantitative control valve 250.

For example, the supply amount of the aerobic microorganism is preferably 0.02 ml per minute.

In addition, the decomposition filtration tank 200 includes therein a treatment tank 260 in a double structure. In the treatment tank 260, the first and second filtration nets 270 and 280 are installed in multiple stages, preferably two stages, The effluent water supplied through the supply pipe 150 is sequentially passed through the first and second filter nets 270 and 280 to be stored at the bottom of the treatment tank 260.

In this process, the aerobic microorganism mixed water injected through the spray nozzle 210 is sprayed on the effluent containing foreign substances such as sludge, and the aerobic microorganisms decompose the organic substances present therein.

Particularly, a discharge hole 290 is formed in a part of the periphery of the treatment tank 260, so that water is discharged in an overflow form through the discharge hole 290.

That is, since there is a space between the treatment tank 260 and the decomposition filtration tank 200, overflows through the space and is collected at the lower end of the decomposition filtration tank 200, (Not shown).

In the bottom of the treatment tank 260, debris, foreign matter, and the like, which are decomposed due to pyrolysis, decomposition of aerobic microbes, and the like are accumulated while the discharged water is stored. In order to facilitate the discharge, The bottom surface is inclined to one side, and the drain piping (VP) for discharging is provided on the inclined side so as to include an on-off valve.

Meanwhile, the agitation agitating tank 300 is equipped with a stirring motor 310 on the upper surface thereof and is configured to be agitated at a low speed for about 3-4 days.

In addition, the stirring blade 330 is fixed to the motor shaft 320 of the stirring motor 310 to increase the stirring efficiency.

At this time, since the aerobic microorganism is sufficiently contained in the stirring aging tank 300, decomposition of the organic matter completely takes place in the fermented form, and the pathogen is also killed by heat.

Thus, when decomposition of the organic matter is completed, the water is drained to the filtration water collecting tank 500 through the discharge processing pipe 400.

The filtration water collecting tank 500 is configured to filter out foreign substances of 0.2 mm or more except for water through the first, second, and third screens 510, 520, and 530 arranged in multi- And is used as a soil material or the like, and the filtered discharged water is collected in the filtration water collecting tank 500, and then returned to the place of use.

As described above, the present invention can increase the degree of purification of effluent water by heating and decomposing aerobic microorganisms, thereby further increasing the recyclability of the effluent water.

10: Storage tank 11: Inflow pump
20: automatic control unit 21, 22, 23:
30: coagulant storage tank 31, 33, 35: metering pump
32: Neutralization agent storage tank 34: Storage tank for coagulation aid
40: flocculation tank 41: neutralization tank
42: Flux forming tank 50: Nano bubble generating device
60: sedimentation tank 61: sludge transfer pump
70: ozone contact tank 71: ozone generator
72: Reused water storage tank 73: Feed pump

Claims

A system for recycling effluent from a sewage treatment plant, comprising:
A flocculation reaction tank into which effluent water is introduced, a flocculant is injected therein, and flocculation reaction treatment is performed with the effluent water; A neutralization tank in which the flocculation reaction treated flocculation reaction water is introduced and a neutralization agent is injected to perform a neutralization reaction treatment; A flocculation tank into which the neutralization-treated neutralized water flows and into which a coagulation aid flows to form a floc; A sedimentation tank through which the flocculated sludge is transferred from the flocculation sludge tank, the flocculation sludge in the fl uid forming water is separated and discharged, and the treated sludge is removed; An ozone contact tank that removes a small amount of total phosphorus and dissolved organic matter remaining in the treated water into which ozone is injected to treat odor, color, turbidity, heavy metals, and E. coli to generate reused water; And a nano bubble generating unit that is connected to the flocculation tank, the neutralization tank, the flocculation tank, and the ozone contact tank and generates nano bubbles respectively in the flocculation tank, the neutralization tank, Generating device;
A flocculant reservoir for storing the flocculant; A first metering pump for introducing the flocculant into the flocculation tank from the flocculant reservoir; A neutralizer reservoir for storing the neutralizer; A second metering pump for introducing the neutralizing agent from the neutralizing agent storage tank into the neutralization tank; A flocculation assistant reservoir for storing the flocculant aid; And a third metering pump for introducing the coagulation aid from the coagulation aid reservoir into the bath;
A first agitator for mixing the effluent and the flocculant in the flocculation tank; A second agitator for mixing the flocculated effluent and the neutralizing agent in the neutralization tank; And a third agitator for mixing said neutralization water and said flocculation aid in said flocking tank;
The treated water discharged through the discharge end of the ozone contact tank is stored in the reused water storage tank, and the discharge end of the reused water storage tank is connected to the upper portion of the heating tank; The heating tank is provided with a drain guide at an upper end portion thereof to guide the drain water drained through the drain end to one direction to smoothly flow into the heat chamber; Wherein the heat chamber is a rectangular box-shaped chamber sealed inside, the burner being installed to pass through one side of the heat chamber to heat the inside of the heat chamber to a high temperature of 300-400 DEG C; A plurality of discharge water pipes for heat exchange are arranged in a zigzag form in the heat chamber so that the discharged water guided through the water drain guide is indirectly heated while exchanging heat with high temperature heat supplied from the burner while being perfused; The heat exchanged effluent is configured to be discharged to the top of the heat chamber; A supply pipe is connected to discharge waste water collected in the lower portion of the heating tank after being discharged to the upper portion of the heat chamber to the decomposition filtration tank; The decomposition filtration tank is a cylindrical member having a funnel shape at its lower end and a pair of spray nozzles at its upper end; The spray nozzle is connected to a microbial mixed water pipe, which is connected to a water tank at an end of the microbial mixed water pipe; Wherein the water tank is provided with a water pump to pump water; The aerobic microorganism tank is connected to a part of the length of the microorganism mixed water pipe, the aerobic microorganism tank is adjusted so that only a certain amount of the aerobic microorganism can be accurately supplied through the quantitative control valve; Wherein said decomposing and filtering tank has a double structure built therein; The first and second filter nets are provided in multiple stages in the treatment tank; The effluent water supplied through the supply pipe is sequentially passed through the first and second filter nets and stored in the bottom of the treatment tank; Wherein a discharge hole is formed in a part of the periphery of the treatment tank so that water is discharged through the discharge hole in an overflow form; Wherein the overflowed effluent is discharged through a transfer tube to a stirred agitation tank; Wherein the agitation agitating tank is provided with a stirring motor on an upper surface thereof; A stirring blade is fixed to the motor shaft of the stirring motor; The decomposed effluent water is drained into the filtration tank through the effluent treatment line; The filtration water collecting tank is configured to filter out all foreign substances of 0.2 mm or more except for water through the first, second and third screens arranged in multi-stages; The filtered foreign substances are discharged through the first, second and third discharge trays; And the filtered effluent is collected in a filtration collecting tank.