KR100413775B1 - Wastewater treatment methods and the apparatus using in sludge reduction and sludge carbon source - Google Patents

Abstract

The present invention relates to a method and apparatus for reducing excess sludge generated during sewage or wastewater treatment and producing a sludge carbon source and injecting it into a bioreactor to recycle the carbon source for denitrification and dephosphorization.

That is, in order to usefully treat sludge which is inevitably generated in a biological wastewater treatment reaction process consisting of an anaerobic tank-anoxic tank-aerobic tank (A2 / O) or anoxic tank-anoxic tank-aerobic tank-aerobic tank (A / O), Ultrasonic reaction tank was installed and some of the excess sludge (microorganism) discarded from the sedimentation basin was subjected to ultrasonic shock in the ultrasonic reaction tank, so that the microorganisms were broken down to elute the organic matter (SCOD) in the microorganism body and the organic matter was The present invention relates to a method and apparatus for advanced treatment of sewage and wastewater using ultrasonic reaction technology for recycling to a carbon source necessary for denitrification.

By using the ultrasonic treatment technology of the present application, it is possible to recycle the excess sludge as a by-product to reduce sludge generation and to provide a technology to produce an excellent carbon source so that denitrification can be performed smoothly without supplying expensive external carbon sources (methanol, etc.). · Provide the advanced wastewater treatment technology to provide a method and device for economic and environmentally friendly operation of wastewater treatment facilities.

Description

Wastewater treatment methods and the apparatus using in sludge reduction and sludge carbon source}

The present invention relates to a method for reducing the excess sludge generated during sewage or wastewater treatment and recycling it to a carbon source for denitrification and dephosphorization by recycling it in a bioreactor and a device for the same.

The present invention is a shortage of energy sources due to the low concentration of influent water and contaminants resulting from the application of sewage and wastewater treatment facilities of A2 / O or A / O bioreaction treatment processes, which are general water treatment advanced treatment methods It is to find a way to drastically improve the problem of lowering material removal efficiency.

It is an object of the present invention to produce microbial carbon source by sonication of surplus sludge, which is a by-product that is inevitably generated during sewage and wastewater treatment, and to stably supply the carbon source required for denitrification to an anoxic tank of a bioreactor, so that the efficiency of denitrification and dechlorination is improved. This is to maximize the advanced processing performance by improving.

Another object of the present invention is to reduce the sludge and reduce the cost by recycling the excess sludge to the carbon source production. The aim is to find economic operating conditions for wastewater treatment and to provide environmentally friendly sewage and wastewater treatment technologies.

It is another object of the present invention to provide a carbon source that can replace expensive external carbon sources such as methanol, ethanol and acetic acid, and to apply the ultrasonic treatment technology to sewage and wastewater treatment of organic materials, nitrogen, phosphorus, etc. It aims to improve the water quality by improving the removal efficiency and contribute to the technical improvement of related fields.

Most biological sewage treatment processes inevitably release sludge. Domestic sludge treatment technology is mostly dependent on enrichment, low-efficiency anaerobic digestion, dehydration, and landfilling. Conventional waste sludge treatment methods require a lot of landfills, so it is expensive, and the cost of waste sludge treatment accounts for half of the total cost of sewage treatment. Is a serious problem that causes secondary pollution, which could lead to global devastation.

In addition, in the conventional biological treatment process, expensive external carbon sources such as methanol and acetic acid, or anaerobic fermentation broths of food or manure were used to solve the problem of lack of carbon source and reduction of removal efficiency. It was a very difficult problem.

In the conventional process for removing nitrogen and phosphorus in general A2 / O or A / O process, the denitrification in the anoxic tank is performed mainly because the carbon source in the influent reduces the nitrate nitrogen contained in the external conveying sludge or the phosphorus release action. In order to solve this problem, VFAs such as methanol and acetic acid, food waste, and manure water fermentation broth are used as carbon sources to solve this problem, but this causes high cost to increase the treatment cost of wastewater. It was difficult to apply in the field due to various obstacles such as transportation, risk of transportation, cumbersome operation of the facility, and skillful operation skills, and high fermentation time and large facilities and equipment.

The present invention is to solve the conventional problems as described above, and to reduce the sludge as well as to purchase the external carbon source by reducing the sludge generated from the biological sewage, wastewater treatment process can be recycled as a carbon source for denitrification, dephosphorization. It is intended to provide economical operating conditions for sewage and wastewater treatment and to provide environmentally friendly sewage and wastewater treatment technology because it provides a stable carbon source without supply.

That is, a separate ultrasonic reaction tank is installed to usefully treat sludge generated in the wastewater treatment reaction process consisting of anaerobic tank, anoxic tank, aerobic tank (A2 / O) or anoxic tank, anoxic tank, aerobic tank, and aerobic tank (A / O). Part of the sludge (microorganisms) disposed of in the sedimentation basin is decomposed into microorganisms by ultrasonic shock in an ultrasonic reaction tank to dissolve organic matter (SCOD) in the microorganisms, and recycles this organic material as a carbon source for denitrification in an anoxic tank. It relates to an advanced wastewater treatment method and apparatus.

In more detail, some of the excess sludge that is inevitably generated during the biological treatment of sewage or wastewater is subjected to ultrasonic shock stress for more than 5 hours under specific ultrasonic reaction conditions, thus destroying the sludge (microorganism) and By dissolving organic matter (SCOD), the sludge is firstly reduced, and the eluted organic matter is continuously supplied to the carbon source (SCOD) necessary for denitrification of an anoxic tank, thereby solving the problem of carbon source shortage and maximizing nitrogen removal efficiency and consequently sludge generation amount. It is to provide a technique to reduce the degree.

In order to supply carbon sources to conventional bioreactors, the inventors have instead purchased and supplied expensive external carbon sources such as methanol, acetic acid, and butyl acid, and secured high quality carbon sources. In order to find the environment and conditions that can maximize the need for constant research.

At present, most domestic sewage treatment plant inflows have a biological oxygen demand (BOD) of about 60 ~ 130 mg / l, which is insufficient to remove nitrogen due to the lack of carbon sources. It has emerged as an obstacle to operational management. Therefore, if the carbon source shortage cannot be effectively solved, denitrification is difficult even if the nitrified treated water from the aerobic tank flows into the anoxic tank, and a separate and expensive external carbon source supply is needed to solve this problem.

The inventors transfer surplus sludge which is inevitably generated during the biological treatment of sewage or wastewater to the ultrasonic reaction tank and irradiate the ultrasonic wave under the ultrasonic reaction condition to destroy the sludge (microorganism) and destroy the organic matter (SCOD) in the microorganism. This study was conducted to find the conditions for reducing the sludge and using this eluate (SCOD) as a useful carbon source for denitrification.

By recycling excess sludge, a by-product that is inevitably generated during water treatment, the energy source is increased by about 100 times more than the initial SCOD _Mn concentration through ultrasonic reaction, and continuously supplied to an anoxic tank (denitrification tank) to maximize denitrification efficiency, and surplus sludge By reducing the amount of sludge generated and disposal costs, in particular, it is possible to solve the problem of operation limitation and efficiency reduction of wastewater treatment plant caused by depletion of energy source in the process of nitrogen removal of sewage and wastewater due to lack of carbon source and to reduce surplus sludge. There is no proper way to recycle surplus sludge, which is a problem in the treatment method by ocean dumping, and it converts sludge into carbon source in an ultrasonic reactor and produces it in an anaerobic tank which is a biological reaction tank. By supplying a stable and continuous supply of carbon source for reducing nitrate nitrogen (NO ₃ -N) to the anoxic tank by maximizing nitrogen removal efficiency and dephosphorization by ingesting phosphorus eluted under anaerobic conditions by ingesting phosphorus by microorganisms under aerobic conditions The purpose of this study was to find out the advanced processing technology and conditions of Ilseok Yijo.

The present invention not only reduces the amount of sludge produced by recycling the excess sludge as a by-product using ultrasonic technology, but also provides a technology for producing an excellent carbon source, and can smoothly perform denitrification without supplying expensive external carbon sources (such as methanol). · To provide a method and apparatus to improve the economics and environmental efficiency of wastewater advanced treatment.

In order to implement the present invention, the configuration of an ultrasonic reaction apparatus for converting and producing sludge into a carbon source by using an ultrasonic treatment is to transfer the excess sludge from the reaction tank, the mixing apparatus, the ultrasonic generator, and the excess sludge waste line to the ultrasonic reactor. It consists of a feeder such as a pump, a meter, a pipe and a valve, and a sludge carbon source supply device such as a metering pump and a pipe line for sending an ultrasonic wave-depleted carbon source to an anaerobic tank.

In the present invention, in the process consisting of anaerobic tank, anoxic tank, and aerobic tank (A2 / O) used to remove nutrients in sewage, wastewater, and wastewater, the carbon source included in the influent water reduces or reduces nitrate nitrogen in the return water in the anaerobic tank. It is consumed to elute phosphorus and denitrification is difficult due to depletion of carbon source in anoxic tank, which requires external carbon source. In order to provide an effective and economical solution by making and supplying ultrasonic sludge carbon source using surplus sludge which is a by-product of wastewater treatment. In addition, the ultrasonic sludge carbon source is supplemented with a carbon source that is insufficient in the process consisting of anoxic, anoxic, aerobic, and aerobic (A / O) to provide a technology that can greatly improve the denitrification efficiency. The present invention is to provide a technique for solving the sludge produced in the treatment process in an environmentally friendly way.

1 is a schematic process configuration diagram of an advanced wastewater treatment method using the ultrasonic sludge carbon source of the present invention.

Figure 2 is another process configuration of the wastewater advanced wastewater treatment method using the ultrasonic sludge carbon source of the present invention.

Figure 3 is a schematic diagram of the ultrasonic reaction apparatus of the present invention.

[Description of Symbols for Main Parts of Drawing]

1. Anaerobic tank 2. Anaerobic tank

3. Exhalation tank 4. Settling tank

5. Ultrasonic Reactor 6. Pump

7. External conveying line 8. Internal conveying line

9. Sludge Transfer Line 10. Ultrasonic Carbon Source Supply Line

end. Anaerobic B. Anaerobic

All. Aerobic d. Sedimentation tank

hemp. Ultrasonic reactor f. Pump

four. External transfer line a. Internal Transfer Line

character. Sludge Transfer Line Cha-1 Ultrasonic Carbon Supply Line

Tea-2. Ultrasonic Carbon Source Supply Line

a. Flow control valve b. Metering pump

c. Mixer d. Reaction tank

e. Oscillator f. Electrode Valve

g. Oscillator (AC power supply) h. Cable

i. Sludge Inlet Valve j. Meter k. Sludge Transfer Pump

1. Sludge Carbon Source Supply Line m. Sludge feed line n. tympanum

In order to achieve the above object in the advanced treatment of sewage or wastewater, the present invention converts sludge to a carbon source using an ultrasonic reaction and recycles the carbon source to a bioreactor to improve the removal efficiency of denitrification and delineation. It is about.

The present application is sewage or o. Anaerobic tank, anaerobic tank, aerobic tank (A2 / O) or anoxic tank in the method for reducing sludge produced in the advanced biological treatment process for treating hardly degradable substances such as nitrogen, phosphorus, organic matter, etc. -A separate ultrasonic reaction tank is installed in the bioreactor consisting of anoxic tank, aerobic tank, and aerobic tank (A / O), and 20-20% of the excess sludge discharged from the settling tank is irradiated with ultrasonic waves to destroy sludge (microorganism). Sludge reduction and recycling as carbon source by eluting SCOD from microorganisms and resupplying to an oxygen-free tank of bioreactor as carbon source for denitrification, performing denitrification, dephosphorization, and organic matter removal without supplying external carbon source. It is an advanced sewage and wastewater treatment method.

The operating conditions of an ultrasonic reactor of the present application is the total output 200W~2000W, only per output 0.14W~1.29W, sludge fornication frequency is irradiated over, the sound level 1kW / m ² or higher for 5 hours or more ultrasound 20kHz to the transferred sludge It is a method for advanced treatment of sewage and wastewater, characterized in that the organic matter (SCOD) in the microorganism body is eluted by destruction.

The present invention consists of anaerobic tank- anaerobic bath- aerobic tank (A2 / O) or anoxic tank- anaerobic bath- aerobic tank- (A / O). Sewage and wastewater advanced treatment device for reducing sludge produced by installing separate ultrasonic reaction tank in waste water treatment system and recycling it as carbon source. Ultrasonic reaction tank is a reaction tank and oscillator of stainless steel. ), Vibrator, diaphragm, wire cable and electrode, mixer, sludge transfer line and sludge inlet valve, excess sludge transfer device, sludge transfer pump, metering pump and sludge carbon source supply device, sludge carbon source supply line, flow control valve, etc. The bottom of the reaction tank is combined with a terminal to prevent the adhesive surface from falling off by vibrating heat, and a vibrator integrated with a whole bolt is installed, and these vibrators are organically connected between an oscillator (AC power generator) by an electric wire cable and an electrode. Connected and the output is controlled in the range of 200w ~ 2000w Provides high and waste water treatment apparatus is characterized in that to occur.

The present invention will be described in detail with the drawings presented to implement the technical idea of the present invention.

In the bioreaction process consisting of anaerobic tank (1)-anaerobic tank (2)-anaerobic tank (3) or anaerobic tank (A)-anaerobic tank (B)-anaerobic tank (C)-aerobic tank (D), separate ultrasonic reaction tank (5 or e) 20-50% of the excess sludge by using a sludge conveying device consisting of a pump (k), a meter (j), a sludge conveying line (m) and a sludge inlet valve (i). Sludge cell membranes are destroyed by ultrasonic irradiation of the transported sludge for 5 hours or more to elute organic matter (SCOD _Mn ) in the sludge (microorganism) body. Ultrasonic reaction time is less effective because the SCOD _Mn increase rate is less than 4 hours as shown in Example 2), so the amount of organic matter (SCOD _Mn ) eluted by reacting for 5 hours or more can be improved carbon supply and denitrification efficiency Confirmed.

The eluted organic substance (SCOD _Mn ) is supplied to the anoxic tank (2 or a) of the biological reaction process by a sludge carbon source supply device such as a metering pump (b), a sludge carbon source supply line (1), and a flow control valve (a). It is utilized as a carbon source for denitrification, maximizing nitrogen removal efficiency. By destroying the sludge using ultrasonic waves in this manner, the energy source required for denitrification is increased by about 100 times or more than the initial SCOD _Mn concentration to maximize the denitrification efficiency by using it as the carbon source of the anoxic tank.

To explain the operating conditions of the ultrasonic reactor in detail, the sludge transferred to the ultrasonic reactor was irradiated with ultrasonic waves having a total power of 200 W to 2000 W, an output of 0.14 W to 1.29 W per cross-sectional area, a sound frequency of 20 kHz or more, and an acoustic intensity of 1 kW / m ² or more. The sludge (microorganism) is destroyed to dissolve organic matter in the sludge (microorganism) and used as the denitrification carbon source of the anoxic tank (2 or ga, b).

The configuration of the ultrasonic reaction tank was made of a stainless steel reaction tank (d), oscillator (g; ac power generator), vibrator (e), diaphragm (n), wire cable (h) and electrode (f), mixer (c). ), Sludge conveying line (m) and sludge inlet valve (i), sludge conveying pump (k), metering unit (j) and sludge carbon source supplying device (b) and sludge carbon source supplying line (1) ), The flow control valve (a), etc. may be organically combined.

On the bottom of the ultrasonic reactor, a bolted type vibrator (e), which is integrally formed by penetrating the whole with a bolt so as to prevent the adhesive surface from falling off by vibrating heat, is installed, and the vibrator (e) An ultrasonic device that is organically connected between the oscillator (g; AC power generator) and regulates the output to 200w to 2000w may be used.

Ultrasonic waves are generated in the reaction tank, and the ultrasonic waves are irradiated to the excess sludge transferred to the reaction tank (d) for 5 hours or more under the same reaction conditions to destroy microorganisms (sludge) and organic matter in the microorganisms. The present invention provides a method and apparatus for improving denitrification efficiency by eluting (SCOD _Mn ) as a carbon source for anoxic tanks.

Sludge carbon production process by ultrasonic reaction causes cavitation phenomenon when ultrasonic wave is irradiated to liquid medium (wastewater), and the cavitation bubble generated is the formation of nucleus, growth into bubble, and Repeated creation and destruction, such as rupture. When bubbles are grown and destroyed, hot and high-pressure gases in the bubbles are released instantaneously, resulting in the formation of strong oxidizing substances such as pyrolysis and OH radicals. The purpose of the present invention is to provide a method and apparatus for destroying excess sludge microorganisms by using high temperature and energy caused by shock waves of cavitation bubbles so that intracellular organic matter (SCOD _Mn ) can be eluted and used as an anoxic carbon source for denitrification. On the other hand, the aerobic tank during the process of the present invention may be filled with a carbon polyester carrier immobilized activated carbon particles to immobilize the nitride bacteria to improve the nitrogen removal effect.

Examples of the actual implementation of the present invention to help understanding.

Example 1

The removal performance of each pollutant in the treatment process using the ultrasonic sludge carbon source was investigated in the C sewage treatment plant in Korea.

Anaerobic, anoxic, aerobic tank, the water temperature in the step is configured ultrasonic twos 20.2~8.2, HRT 7.39~5.39hr, BOD volume load average value ^{0.29kg / m 3 · day, F} / M ratio is 0.09 (kg · BOD / kg MLSS · The removal efficiency of contaminants at the time of d) is shown in <Table 1>. The average removal efficiency of contaminants was 89.3% at 79.5mg / l at BOD, 89.3%, CODMn at 9.16mg / l at 51.1mg / l, 82.1%, and TN at 9.47mg / l at 32.1mg / l. The removal efficiency of 70.5% and TP was 3.04mg / l, 1.45mg / l, 52.4%, and TSS was 69.8mg / l, 6.68mg / l, and 89.8%.

<Table 1> Removal performance of each pollutant in the treatment process using ultrasonic sludge carbon source

Example 2)

In this batch experiment, the application of ultrasonic carbon to the sludge of J sewage treatment plant was investigated through batch experiments. The ultrasonic device used in the experiment was used as a method for destroying microorganisms by attaching five ultrasonic vibrators to the bottom of the tank and emitting an ultrasonic wave in the upward direction.The ultrasonic specification used in the experiment was 400 (L). ) 350 (W) 255 (H) (mm), external size 480 (L) 475 (W) 500 (H) (mm), capacity 35,7ℓ, frequency 28-40khz, output 600W . Experimental method was carried out in three stages of the increase in SCODMn, PO4-P concentration by returning the sludge of the J sewage treatment plant in a 35.7 L ultrasonic bath and taking samples at predetermined times. In this batch experiment in which microbial cells were destroyed by ultrasound to determine the possibility of carbon source, the initial SCOD _Mn concentration was slightly different according to sludge MLSS, but the increase in SCOD _Mn according to the ultrasonic irradiation time was shown in <Table 2>. The concentration of SCOD _Mn tended to increase proportionally with time, showing the highest increase at 6hr.

<Table 2> Changes in SCOD _Mn Concentration with Time of Ultrasonic Irradiation

The present invention recycles about 20% to 50% of the sludge produced during the treatment of anaerobic tanks-anaerobic tanks-aerobic tanks (A2 / O) or anaerobic tanks-anaerobic tanks-aerobic tanks-aerobic tanks (A / O), which are sewage or wastewater treatment facilities. It is possible to produce and supply carbon sources scarcely in advanced processing processes. According to the present invention, sludge in a sewage treatment plant can be recycled as a carbon source without using methanol or food waste fermentation broth supplied from the outside for denitrification of the anoxic tank. In particular, considering the low organic matter concentration (BOD) of most domestic sewage treatment plant influent sewage (approximately 60 ~ 13Omg / l), ultrasonic sludge carbon source is produced and supplied by water treatment process to replace external carbon source. The denitrification efficiency of poorly decomposable organic matter can be maintained stably and the nitrogen removal effect can be dramatically improved.

Claims (3)

Sewage or oh. In the method for reducing the sludge generated in the advanced biological treatment process for treating pollutants such as nitrogen, phosphorus, organic matter through the wastewater treatment process and recycling it as a carbon source, A separate ultrasonic reaction tank is installed in the bioreactor consisting of anaerobic tank-anaerobic tank-aerobic tank (A2 / O) or anoxic tank-anoxic tank-aerobic tank-aerobic tank (A / O), and 20 to 50% of surplus sludge discharged from the settling tank is transferred. It receives ultrasonic waves to destroy sludge (microorganisms) and elutes organic matter (SCOD) in the microbial body and supplies it back to the anoxic tank of the bioreactor as a carbon source for denitrification. Advanced sludge and wastewater treatment method for sludge reduction and recycling as carbon source The method of claim 1 The operating conditions of the ultrasonic tank is 200W~2000W total output, output only area 0.14W~1.29W, fornication frequency microorganisms by destroying the sludge by irradiation described above, the sound level 1kW / m ² or higher for 5 hours or more ultrasound 20kHz to the transferred sludge Advanced sludge and wastewater treatment method for sludge reduction and recycling as a carbon source, characterized by eluting organic matter (SCOD) in the body. B) consisting of anaerobic tanks-anaerobic tanks-aerobic tanks (A2 / O) or anaerobic tanks-anaerobic tanks-aerobic tanks-aerobic tanks (A / O). In the advanced sewage and wastewater treatment apparatus for reducing the sludge generated by installing a separate ultrasonic reaction tank in the biological reaction tank of the wastewater treatment system and recycling it as a carbon source, Ultrasonic reactors are stainless steel reaction tanks, oscillators (; AC power generators), vibrators, diaphragms, wire cables and electrodes, mixers, sludge transfer lines and sludge inlet valves, sludge transfer pumps, meters and sludge carbon sources. It consists of a metering pump, a sludge carbon source supply line, a flow control valve, etc., and a vibrator is installed on the bottom of the reaction tank so that the adhesive surface does not fall off by vibrating heat, and the entire vibrator is integrated with bolts. Reduced sludge and recycling wastewater as carbon source, characterized by organically connected between oscillator (AC power generator) by cable and electrode, and controlling output in the range of 200w to 2000w to generate ultrasonic waves in the reaction tank Processing unit.