JP6644222B2 - Sulfur denitrification technology of swine wastewater by a reactor equipped with a simple heating system - Google Patents

Description

  The present invention relates to, for example, denitrification treatment of swine wastewater.

  The total amount of nitrogen components is regulated in closed waters, and nitrogen emission reductions are being made at business sites that discharge to Tokyo Bay, Ise Bay, and the Seto Inland Sea, and the costs are increasing. Furthermore, in the livestock and agriculture sector, especially in Ise Bay, there is a need to comply with total volume regulations. Strict concentration control of nitrate nitrogen is imposed on specified business sites of the Water Pollution Control Law regardless of the amount of wastewater. Under such circumstances, various nitrogen removal technologies have become widespread, but there is a high need in the livestock industry and various industrial fields for the removal technology with less burden on cost and management.

  Conventionally, biological denitrification is the mainstream of nitrogen removal technology, and methanol is often used as an electron donor for denitrification. However, the cost of purchasing methanol and the work of adjusting the appropriate addition amount are burdensome for the business operator, and there are few practical examples in the livestock industry. As described above, in various industrial fields such as the livestock industry, it is required to develop a denitrification method using materials that are inexpensive and do not require addition amount control instead of methanol.

  Incidentally, a sulfur denitrification technology is known as a denitrification technology. In the sulfur denitrification technology, sulfur oxidizing and denitrifying bacteria in treated water (effluent) reduce nitrate nitrogen to nitrogen gas using sulfur and simultaneously generate sulfate ions. In this way, nitrate nitrogen is changed to nitrogen gas and removed. Although various studies have been made on the sulfur denitrification technology, one of the factors that cannot be put into practical use is a decrease in the denitrification activity in a low temperature period. As described above, conventionally, a year-round type sulfur denitrification technology has not been known.

  In addition, the sulfur denitrification reaction requires the addition of an inorganic carbon source for cell growth and the addition of a treated water neutralizing agent. In this case, a method as simple as possible is desired. Further, if bubbles derived from denitrification accumulate in the material layer, smooth contact between the liquid to be treated and the sulfur material is hindered, and the treatment efficiency is reduced. Simple means for preventing this is also required.

  In view of the above-mentioned circumstances, an object of the present invention is to provide a simple sulfur denitrification treatment method and a treatment apparatus for swine wastewater of a year-round type.

  As a result of intensive research to solve the above-mentioned problems, pig farm wastewater was subjected to sulfur denitrification treatment under the heating conditions through the high water temperature throughout the year in the aeration tank of the existing facility, utilizing the characteristics of the pig farm wastewater treatment facility. It has been found that the use of this method enables denitrification from swine wastewater over the whole year including the low temperature period, and has completed the present invention.

The present invention includes the following.
(1) A method for removing swine wastewater, comprising: a sulfur material-containing tank for subjecting swine wastewater to a sulfur denitrification treatment; and means for heating the liquid temperature in the sulfur material-containing tank through the heat of the liquid temperature in the aeration tank. Nitrogen treatment equipment.
(2) The denitrification treatment apparatus according to (1), further comprising means for heating the liquid temperature in the sulfur-containing tank via solar heat.
(3) The denitrification treatment apparatus according to (1) or (2), further comprising means for supplying a saturated sodium bicarbonate solution into the sulfur material-containing tank.
(4) The device according to any one of (1) to (3), further comprising a unit for removing bubbles of nitrogen bubbles accumulated in the sulfur material layer by vibrating the vibrator provided on the outer surface of the sulfur material-containing tank or in the sulfur material layer. Denitrification equipment.
(5) A method for denitrifying swine wastewater, comprising the step of subjecting swine wastewater to sulfur denitrification while heating through the heat of the liquid temperature in an aeration tank.
(6) The method according to (5), further comprising performing a sulfur denitrification treatment under heating through solar heat.
(7) The method according to (5) or (6), wherein the saturated sodium bicarbonate solution is supplied to swine wastewater to perform a sulfur denitrification treatment.
(8) Any one of (5) to (7), wherein the nitrogen bubbles accumulated in the sulfur material layer are denitrified while being defoamed by the vibration of a vibrator provided on the outer surface of the sulfur material-containing tank or in the sulfur material layer. The method of claim 1.

  According to the present invention, in a swine wastewater treatment facility, denitrification can be performed from swine wastewater over a year.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the denitrification processing apparatus of the swine wastewater concerning this invention. 4 is a graph showing the effect of introducing the heating system in winter in Example 1. 4 is a graph showing nitrogen removal performance in winter in Example 1. 4 is a graph showing the relationship between the water temperature in the denitrification device and the nitrogen removal rate in Example 1. It is a graph in Example 2 which shows the heating effect which used septic tank heat and solar heat together. 9 is a graph showing the relationship between alkalinity and nitrogen removal rate in Example 3.

  The swine wastewater denitrification treatment apparatus according to the present invention (hereinafter, referred to as “the present apparatus”) is a sulfur material-containing tank for subjecting swine wastewater to sulfur denitrification treatment, and the sulfur through a heat of the liquid temperature in the aeration tank. Means for heating the liquid temperature in the material-containing tank. Further, the method for denitrifying swine wastewater according to the present invention includes a step of using the present apparatus to subject swine wastewater to sulfur denitrification treatment under heating through the heat of the liquid temperature in the aeration tank.

  In the sulfur denitrification treatment, the denitrification activity decreases in the low temperature period. Therefore, in the present invention, the denitrification activity of sulfur oxidizing and denitrifying bacteria in swine wastewater is performed by subjecting swine wastewater to sulfur denitrification treatment under heating through the heat of the liquid temperature in the aeration tank of the swine wastewater treatment facility. And denitrification from swine wastewater throughout the year.

  Existing swine wastewater treatment facilities are equipped with an aeration tank for subjecting swine wastewater to the activated sludge process. The activated sludge method is a treatment method comprising first sedimentation, aeration, and final sedimentation. In the first sedimentation, physical treatment is first performed by gravity sedimentation, and then the obtained supernatant is put into an aeration tank. In the aeration tank, an aerobic microbial treatment is performed by activated sludge, and organic matter is decomposed. In the final sedimentation, the activated sludge is settled, and a part of the sludge is returned to the aeration tank, whereby the sludge concentration is adjusted. Further, the supernatant liquid after the final precipitation becomes treated water. In the aeration tank, a high water temperature throughout the year (for example, 15 ° C. or higher even in winter) is often maintained by the heat of the blower and the ground temperature.

  Here, swine raising wastewater means wastewater containing manure and washing water in a piggery. Swine wastewater contains sulfur oxidizing and denitrifying bacteria that perform a sulfur denitrification reaction (a reaction that reduces nitrate nitrogen to nitrogen gas using sulfur and simultaneously produces sulfate ions). In the present invention, nitrate nitrogen is converted into nitrogen gas by sulfur oxidizing and denitrifying bacteria in swine wastewater, and nitrogen can be released out of the system.

  FIG. 1 is a schematic diagram illustrating an example of the present apparatus. As shown in FIG. 1, the present apparatus 1 includes sulfur material-containing tanks 2 a and 2 b and a heating unit 4 through the heat of the liquid temperature in the aeration tank 3. The aeration tank 3 is an aeration tank in an existing purification facility, and does not constitute the present apparatus.

  The sulfur material-containing tanks 2a and 2b are, for example, earth and sand sedimentation separation tanks (notch tanks) for civil engineering work. The sulfur material-containing tank is to be installed after the existing swine wastewater treatment facility, and performs denitrification for the effluent (swine wastewater) from the facility. As the sulfur material-containing tanks 2a and 2b, two notch tanks are arranged in series. The inside of each tank is divided into three sections (referred to as "first to third sections") by a partition plate, and sulfur is added to the bottom of the first section 5a and the second section 5b of the notch tanks 2a and 2b. Material 6 is charged, and treated water (pig raising wastewater; raw water) 7 from the existing facility flows into the first section 5a of the notch tank 2a, and flows down naturally to the third section 5c of the notch tank 2b. The liquid passes through the material layer while flowing down, and the nitrate nitrogen is changed into nitrogen gas by the sulfur denitrification reaction at this time, and is removed out of the system.

  Here, examples of the sulfur material include powdered sulfur that is distributed as a material for adjusting soil pH for agriculture, and coarse sulfur that is distributed as an industrial raw material. In the case of powdered sulfur, since it is hydrophobic, it is used after being subjected to hydrophilization treatment with a neutral detergent. As the sulfur material, for example, 100 to 138.2 kg (preferably 100 kg) is supplied per notch tank having an effective volume of 500 L. On the other hand, the treated water has, for example, an inflow rate of 320 to 1460 mL / min (preferably 336 to 491 mL / min) and a hydraulic retention time (HRT) per effective volume of water of 0.5 to 2.2 days (preferably 1.4 to 2.1 days). It is put continuously. Sulfur oxidizing and denitrifying bacteria grow on the surface of the sulfur material in the tank, and denitrification using sulfur proceeds.

  Sulfur oxidizing and denitrifying bacteria utilize sulfur to reduce nitrate nitrogen to nitrogen gas and simultaneously produce sulfate ions. Therefore, when sulfur denitrification is activated, the pH tends to decrease. Therefore, in order to prevent the pH of the treated water from dropping and to supply carbonate ions necessary for the growth and denitrification of sulfur denitrifying bacteria, a baking soda storage tank 8 containing baking soda at a saturation concentration or higher is installed. A saturated baking soda solution adjusted by supplying tap water or circulating water with a pump from the baking soda storage tank 8 into the first section 5a of the notch tank 2a as appropriate (refer to the "saturated baking soda solution Means for supplying into the containing tank "). For example, tap water is passed from the bottom to the baking soda storage tank with baking soda precipitated at the bottom for 1 to 4 minutes every 12 hours (preferably 1 minute), with an inflow of 679 to 2020 mL / min (preferably 800 mL / min). Then, let the saturated baking soda solution flow out from the upper part of the baking soda storage tank to the notch tank. In addition, a part of the liquid may be circulated to the baking soda storage tank 8 through the circulation line 10 by the circulation pump 9 charged into the third section 5c of the notch tank 2b. Alternatively, as a simple method, a required amount of baking soda 11 may be filled in the bottom of the third section 5c of the notch tank 2a. The filled baking soda is gradually dissolved and diffused into the notch tank 2a and the notch tank 2b by the circulation line 12, and exerts effects on sulfur denitrification and neutralization.

  On the other hand, in order to secure the water temperature necessary for maintaining the denitrifying activity of the sulfur oxidizing and denitrifying bacteria, a part of the liquid is supplied to the first section 5a of the notch tank 2a by the circulation pump 13 which is charged into the third section 5c of the notch tank 2b. Circulate. A part of the circulation line 12 is provided with a stainless steel flexible pipe for water supply as a heating means 4, and the apparatus 1 is heated using the liquid temperature in the aeration tank 3 of the existing swine wastewater treatment facility. The stainless flexible tube is immersed in a liquid in an aeration tank in a form of, for example, a coil having a length of 5 to 10 m (preferably 10 m) and transfers the heat of the liquid in the aeration tank to the liquid in the notch tank.

  Further, a solar hot water panel 14 can be installed as a heating means via solar heat to assist heating in a severe cold season. For example, clear water flowing between two thin plates made of polycarbonate is heated by sunlight, and the hot water is circulated by a pump 16 driven by a solar cell 15 through a stainless flexible pipe 17 immersed in a liquid in a notch tank. The heat is transferred to the liquid in the notch tank. Similarly to the above, the stainless flexible tube is disposed in the liquid in the notch tank, for example, in the form of a coil having a length of 10 m.

  According to these heating systems, the water temperature in the notch tank can be maintained at a certain level or more even in the low temperature period.

  The treated water 18 can be appropriately discharged from the third section 5c of the notch tank 2b to the outside of the system.

  The vibrator 19 vibrates or defoams the sulfur material layer constantly or periodically to prevent nitrogen bubbles generated from the surface of the sulfur material from being embedded in the sulfur material layer and hindering contact between the sulfur material and the raw water. be able to. The vibrator is disposed on the outer surface of the notch tank or in the material layer by, for example, a pneumatic vibrator or a knocker.

  Hereinafter, the present invention will be described in more detail with reference to Examples, but the technical scope of the present invention is not limited to these Examples.

[Example 1] Introduction effect of heating system (use of aeration tank liquid temperature) and denitrification activity in winter 1. Experimental conditions
1-1. Denitrification treatment equipment Two commercially available rectangular sedimentation separation tanks (notch tanks) with an effective volume of 500 L (Suiko Co., Amagasaki) were connected and used as a reactor with an effective water volume of 1000 L. The inside of the tank is divided into three sections (referred to as `` first to third sections '') by a partition plate, and the water flowing from the first section passes through the gap between the partition plate and the bottom surface, and flows from the top of the second section to the second section. Overflows into three compartments and is discharged as treated water. Therefore, by charging the powdered sulfur into the first section and the second section of each tank, efficient contact between the sulfur material and the flowing water is possible.

1-2. Sulfur material As the sulfur material, powdered sulfur for soil pH adjustment used in cultivation of blueberries and the like (sulfur content: 99% or more, 200 mesh pass, Nature Rest Office, Kagawa) was used. Powdered sulfur cannot be used for denitrification treatment as it is because of its water repellency. However, by adding an appropriate amount of a neutral detergent for home use and stirring, it becomes hydrophilic and precipitates in water. A total of 200 kg of the powdered sulfur subjected to the hydrophilization treatment was charged at 100 kg per one notch tank.

1-3. Test method The water to be treated in the test (swine wastewater; influent water to the denitrification equipment) is supplied from the treated water storage tank of the existing purification facility by a tubing pump with an inflow of 336 to 1460 mL / min. It was continuously charged into the denitrification unit with a hydraulic residence time (HRT) of 0.5 to 2.1 days. Since the concentration of nitrate nitrogen in the influent water dropped to 100 mg / L or less after the start of the test, a sodium nitrate solution storage tank was installed, and the solution was added to the influent water by a chemical injection pump, so that the nitrate nitrogen concentration was reduced. Was increased to about 200 mg / L for the test. Inoculation of sulfur oxidizing and denitrifying bacteria was not performed.
The operation was carried out for 76 days during the winter season (December 18, 2014 to March 3, 2015).

1-4. Installation of baking soda addition equipment In order to prevent the treated water from being acidified by the sulfate ions generated by the denitrification reaction and to supply the carbonate ions necessary for the denitrification reaction, the denitrification equipment should be equipped with a saturated sodium bicarbonate as appropriate. Solution addition was performed. In the baking soda addition apparatus, an open-top, square-shaped plastic container (effective water volume: about 68 L) was used, and 25 kg of baking soda for general industrial use was charged. Since this input amount greatly exceeded the saturation concentration, most of the amount did not dissolve and settled at the bottom of the container. Tap water was passed from the bottom of the container by a timer-type sprinkler (G225; Takagi, Kitakyushu) at an inflow rate of about 0.8 L / min for 1 minute every 12 hours, and a saturated sodium bicarbonate solution was allowed to flow out from the top. Since the amount of precipitated sodium bicarbonate gradually decreased, sodium bicarbonate was supplemented before disappearing.

1-5. Introduction of heating system (use of aeration tank liquid temperature) Heating in the denitrification equipment for 25 days from February 6, 2015 to March 3, 2015 after the 51st day of the test As a countermeasure, a submersible pump was installed as a circulation pump in the third section of the second tank, and a line for returning the liquid to the first section of the first tank was incorporated. A part of this circulation line is a stainless flexible tube (5 m until February 18, then extended to 10 m), and the coiled flexible tube is immersed in the aeration tank mixture of the existing purification facility, and the aeration tank mixture Was transferred to the denitrifier.

2. Result
2-1. Effect of introducing the heating system in winter As shown in Fig. 2, the average outside water temperature is 6.3 ° C before the introduction of the heating system (using the aeration tank liquid temperature), whereas the average internal water temperature is 10.0 ° C. It was changed. In contrast, after the introduction of the heating system, the average internal water temperature changed to 15.4 ° C against the average outside temperature of 6.7 ° C. Since the average outside air temperature hardly changed before and after the introduction of the heating system, it was considered that the rise in water temperature in the device was due to the liquid temperature of the aeration tank being effectively transferred into the device by the circulation line equipped with stainless flexible tubes. . It is presumed that the liquid in the aeration tank of the activated sludge method was maintained at a higher temperature than the outside temperature due to the heat of the blower and the ground temperature even in the low temperature period. Since the water temperature in the equipment followed the aeration tank liquid temperature by a difference of -1.0 ± 0.7 ° C (mean ± standard deviation), this system increased the temperature of the aeration tank to the same level as the liquid temperature in the aeration tank even in the low temperature period. It can be said that it is possible to warm.

2-2. Nitrogen removal performance in winter As shown in Fig. 3, the nitrate concentration of raw water before introduction of the heating system was 155.4 ± 43.3 mg / L, while the nitrate concentration of treated water was 112.9 ± 41.5 There was no significant change at mg / L, and the nitrogen removal rate was low at an average of 29.0%. During this period, the water temperature in the apparatus fluctuated in the range of 7.0 to 13.0 ° C., and was 10.0 ° C. on average. In general, it has been confirmed that the activity of sulfur denitrification is remarkably reduced below 10 ° C. Therefore, heating is indispensable for maintaining the denitrification activity in a low temperature period.

  After the introduction of the heating system, the nitrate nitrogen concentration of the treated water decreased to 62.4 ± 19.0 mg / L against the nitrate nitrogen concentration of the raw water of 167.0 ± 28.8 mg / L (average nitrogen removal rate 66.6%). The nitrate nitrogen in the treated water after the introduction of the heating system gradually decreased, and on the 65th day, the removal rate increased to 82.4%. Since the average nitrate nitrogen concentration of the treated water was 62.4 mg / L, it can be said that the concentration was reduced to 100 mg / L or less, which is the general standard value. During this period, the water temperature was in the range of 13.5-17.7 ° C, averaging 15.4 ° C. This is considered to be a factor of the increase in the denitrification activity.

2-3. Relationship between denitrification equipment water temperature and nitrogen removal rate As shown in Fig. 4, the relationship between water temperature in the equipment and nitrogen removal rate is almost linear, and the removal rate tends to increase as the water temperature increases. Was. The removal rate after the introduction of the heating system was approximately 60% or more, and a removal rate of 82.4% was obtained at a water temperature of 15.5 ° C. Therefore, the goal was to maintain the water temperature in the device at 15 ° C or more. I can say. Conversely, if the water temperature was lower than 10 ° C., no practical performance was exhibited.

[Example 2] Heat retention effect of water temperature in denitrification equipment accompanying introduction of solar hot water panel
1. Experimental conditions
1-1. Denitrification treatment device The denitrification treatment device was the same as in Example 1.

1-2. Sulfur material Crude sulfur used for industrial purposes was used as the sulfur material. Crushed sulfur is a material that includes materials ranging from close to fine powder to coarse particles with a diameter of about 40 mm. Unlike powdered sulfur, it settles in water as it is, so that no hydrophilic treatment is required. 100kg per notch tank, a total of 200kg was injected.

1-3. Test method The inflow water (swine wastewater) into the denitrification equipment is supplied from the treated water storage tank of the existing purification facility by a tubing pump at an inflow rate of 395 to 682 mL / min, and HRT per effective water volume of 1.0 to 1.8 days. It was continuously charged into the denitrification equipment. In order to increase the concentration of nitrate nitrogen in the influent water, a sodium nitrate solution storage tank was installed, and the solution was added to the influent water by a chemical injection pump to increase the nitrate nitrogen concentration to about 178 to 513 mg / L. The test was performed. Inoculation of sulfur oxidizing and denitrifying bacteria was not performed.
The operation was tested between April 23, 2015 and May 18, 2015.

1-4. Installation of baking soda addition device The installation of baking soda addition device was the same as in Example 1.

1-5. Introduction of heating system (use of aeration tank liquid temperature) Introduction of a heating system (use of aeration tank liquid temperature) was the same as in Example 1.

1-6. Introduction of heating system (use of solar hot water panel) A heating system using a solar hot water panel was introduced. Two hollow polycarbonate boards (1.8m long x 0.9m wide x 4.5mm thick, 6L capacity, Soft Energy Laboratory, Kashiwa) were connected with a hose to form a solar hot water panel. Water heated by sunlight inside the panel is circulated between the panel and the stainless flexible pipe (length 10m) by a solar cell driven pump only when receiving direct light. By immersing this flexible tube in the liquid in the denitrification device, the solar heat was transferred.

2. Results Heating effect using combined use of septic tank heat and solar heat As shown in Fig. 5, data is shown when the solar cell is operating well under sunshine. During this period, the water temperature in the equipment was 22.4 to 32.4 ° C (29.3 ± 3.4 ° C), the outside temperature was 21.5 to 27.4 ° C (24.5 ± 2.4 ° C), and the aeration tank liquid temperature was 22.1 to 26.3 ° C (24.7 ± 1.4 ° C). there were. In particular, the water temperature inside the equipment rose to 32.4 ° C on the 21st day, rising to an outside temperature of + 10.5 ° C and an aeration tank liquid temperature of 7.1 ° C. This is probably because solar heat was transferred to the device. The difference between the internal water temperature and the outside air temperature was 4.8 ± 2.9 ° C, and the temperature difference between the internal water temperature and the aeration tank liquid temperature was 4.6 ± 2.7 ° C. It is thought that the water temperature can be raised by about 5 ° C. Since the use of solar heat is limited to when there is sunshine, there is a merit of using it as a heating aid during a severe cold season or as an emergency measure in the case of poor or sudden malfunction of the aeration tank.

[Example 3] Effect of supply of carbon source by adding sodium bicarbonate on denitrification activity
1. Experimental conditions
1-1. Denitrification treatment device The denitrification treatment device was the same as in Example 1.

1-2. Sulfur material Crude sulfur used for industrial purposes was used as the sulfur material. Crushed sulfur is a material that includes materials ranging from close to fine powder to coarse particles with a diameter of about 40 mm. Unlike powdered sulfur, it is settled in water as it is, so that no hydrophilization treatment is required. A total of 268.2 kg of 130 kg was put into the first notch tank and 138.2 kg was put into the second tank.

1-3. Test method The inflow water (swine effluent) into the denitrification equipment is from the treated water storage tank of the existing purification facility using a tubing pump with an inflow of 320 to 453 mL / min, and an HRT of 1.5 to 2.2 days per effective water volume. It was continuously charged into the denitrification equipment. In order to increase the concentration of nitrate nitrogen in the influent water, a sodium nitrate solution storage tank was installed, and the solution was added to the influent water with a chemical injection pump to increase the nitrate nitrogen concentration to about 329 to 440 mg / L. The test was performed. For continued testing from Example 2, inoculation of sulfur oxidizing and denitrifying bacteria was performed.
The operation was tested between September 7, 2015 and October 13, 2015.

1-4. Installation of baking soda addition device The installation of baking soda addition device was the same as in Example 1. Using an open-top, rectangular plastic container (effective water volume: about 68 L), 25 kg of general industrial baking soda was charged. Since this input amount greatly exceeded the saturation concentration, most of the amount did not dissolve and settled at the bottom of the container. From the bottom of this container, tap water is sprinkled with a timer-type sprinkler (G225; Takagi, Kitakyushu) for 3 minutes every 12 hours from 9/7 to 9/29, with an inflow of 780 to 2020 mL / min, and 9/3 to 10 Water was passed at a flow rate of 679 to 845 mL / min for 4 minutes every 12 hours until / 13, and a saturated sodium bicarbonate solution was allowed to flow out from the top. Since the amount of precipitated sodium bicarbonate gradually decreased, sodium bicarbonate was supplemented before disappearing.

1-5. Introduction of heating system (use of aeration tank liquid temperature) Introduction of a heating system (use of aeration tank liquid temperature) was the same as in Example 1. In addition, the heating system (use of the solar hot water panel) was not introduced.

2. Results Relationship between alkalinity and nitrogen removal rate As shown in FIG. 6, the relationship between alkalinity and the removal rate was shown for the effect of carbonate ions required for the denitrification reaction on the nitrogen removal rate. The relationship between the alkalinity and the nitrogen removal rate was generally linear, and the removal rate tended to increase as the alkalinity increased. Regarding the appropriate range of alkalinity effective for denitrification activity, it can be said that a removal rate close to 80% can be obtained by increasing the alkalinity to about 400 mg / L.

1: Denitrification treatment equipment 2a, b for swine wastewater according to the present invention: Sulfur material containing tank (notch tank)
3: Aeration tank 4: Heating means via the heat of the liquid temperature in the aeration tank (stainless flexible pipe)
5a: first section 5b: second section 5c: third section 6: sulfur material 7: raw water 8: baking soda storage tank 9: circulation pump 10: circulation line 11: baking soda 12: circulation line 13: circulation pump 14: solar hot water panel 15: solar cell 16: pump 17: stainless flexible tube 18: treated water 19: vibrator

Claims (8)

A sulfur material-containing tank for subjecting swine wastewater to sulfur denitrification treatment,
Means for heating the liquid temperature in the sulfur material-containing tank via the heat of the liquid temperature in the aeration tank, the means being a stainless flexible pipe installed in the aeration tank ,
A circulation line in which the stainless flexible tube is installed as a part,
A circulation pump that circulates a part of the liquid in the sulfur material-containing tank by the circulation line, and transfers heat of the liquid temperature in the aeration tank to the liquid in the sulfur material-containing tank;
A denitrification treatment device for swine wastewater.   The denitrification treatment apparatus according to claim 1, further comprising: means for heating the liquid temperature in the sulfur material-containing tank via solar heat.   The denitrification treatment apparatus according to claim 1 or 2, further comprising a unit for supplying a saturated sodium bicarbonate solution into the sulfur material-containing tank.   The denitrification treatment according to any one of claims 1 to 3, further comprising means for defoaming nitrogen bubbles accumulated in the sulfur material layer by vibrating a vibrator provided on the outer surface of the sulfur material-containing tank or in the sulfur material layer. apparatus. The pig drainage, viewed including the step of subjecting the sulfur denitrification with heating under through the aeration tank liquid temperature of the heat, the heating was placed stainless flexible tube installed in the aeration tank as part The pig raising is performed by circulating a part of the liquid in the sulfur material-containing tank for performing the sulfur denitrification treatment by the circulation line and transferring heat of the liquid temperature in the aeration tank to the liquid in the sulfur material-containing tank. Wastewater denitrification method.   The method according to claim 5, further comprising performing a sulfur denitrification treatment under heating via solar heat.   The method according to claim 5 or 6, wherein a sulfuric acid denitrification treatment is performed by supplying a saturated baking soda solution to swine wastewater.   The method according to any one of claims 5 to 7, wherein the denitrification treatment is performed while defoaming nitrogen bubbles accumulated in the sulfur material layer by vibrating a vibrator provided on the outer surface of the sulfur material-containing tank or in the sulfur material layer. .

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