TWI750735B - Biological nitrogen removal system for nitrogen-containing wastewater and nitrogen removal method - Google Patents

Abstract

A biological nitrogen removal system for nitrogen-containing wastewater and nitrogen removal method, the system includes a control processor, a pre-aeration section, a biological nitrogen removal section and a water storage tank along the sequence of wastewater treatment, the pre-aeration section is defined with a pre-aeration tank having an aeration assembly and a pH value monitor electrically controlled by the control processor, thus, the nitrogen removal method is prior to the biological nitrogen removal treatment procedure of nitrogen-containing wastewater, the nitrogen-containing wastewater is pre-aerated to increase the concentration of inorganic carbon in water and acid-base buffer, so as to supplement the inorganic carbon and alkalinity consumed in the back-end biological nitrogen removal process, improving the treatment efficiency of biological nitrogen removal system and reducing the operating cost.

Description

Biological nitrogen removal system and nitrogen removal method for nitrogenous sewage

The present invention relates to a sewage treatment system and a treatment method thereof, in particular to a biological nitrogen removal system for nitrogen-containing sewage and a nitrogen removal method thereof.

Ammonia nitrogen (NH ₄ ⁺ -N) is a universal man-made pollutant, and its discharge into water will increase the biological toxicity of the water body, and consume the dissolved oxygen in the water body, causing damage to the water environment. In recent years, the global natural nitrogen balance has been affected by industrial emissions and human activities, resulting in serious imbalance hazards. In the impact of water bodies, groundwater, tap water and natural water bodies can all cause hazards, such as optimization and related health concerns. Therefore, with the development of high-tech industries and industrial processes, environmental regulations have also become stricter, and the treatment technology of nitrogen-containing sewage is also a project that attracts special attention. At present, the biological treatment of sewage containing nitrogen is also one of the technologies of choice. The traditional biological reaction system can be mainly divided into anaerobic-aerobic treatment method (Anoxic-Oxic system, or MLE method), aerobic-anaerobic treatment system (Oxic-Anoxic system), anaerobic ammonia nitrogen oxidation method (Anammox system). ).

It is worth noting that most of the obstacles to the application of biological nitrogen removal systems at present come from the cost of chemicals brought by the operation of the system and the cost factors such as the installation space and land of the biological system. Specifically, the aerobic unit in the traditional biological nitrogen removal technology includes the biological nitrification reaction, which is the reaction in which microorganisms in the biological system convert ammonia into nitrate, as shown in the following [Equation 1]. The reaction process consumes inorganic carbon and alkali. Spend.

[Formula 1] NH ₄ ⁺ + 1.863 O ₂ + 0.098 CO ₂ → 0.0196 C ₅ H ₇ O ₂ N +0.98 NO ₃ ⁻ + 0.0941 H ₂ O +1.88 H ⁺

In addition, the anaerobic ammonium nitrogen oxidation system includes a short-range nitrification reaction, that is, the reaction of microorganisms in the biological system to convert ammonia into nitrite, as shown in the following [Equation 2], and the reaction process will also consume inorganic carbon and alkalinity.

[Formula 2] NH ₄ ⁺ + 1.38 O ₂ + 0.09 HCO ₃ ^- → 0.018 C ₅ H ₇ O ₂ N + 0.982 NO ₂ ^- + 1.036 H ₂ O + 1.89 H ⁺

Furthermore, in the anaerobic ammonium nitrogen oxidation system, the anaerobic ammonium nitrogen oxidation reaction is shown in the following [Equation 3], which is different from the denitrification reaction in that the anaerobic ammonium nitrogen oxidation reaction uses nitrous acid as the electron acceptor and converts ammonia into Oxidation to nitrogen, which also consumes inorganic carbon.

[Formula 3] NH ₄ ⁺ + 1.31 NO ₂ ^- +0.066 HCO ₃ ^- +0.13 H ⁺ → 1.02 N ₂ + 0.26 NO ₃ ^- +0.066 CH ₂ O _0.5 N _0.15 + 2.03 H ₂ O

As explained in the previous [Formula 1], [Formula 2], [Formula 3], it can be seen that inorganic carbon and alkalinity will be consumed during the biological treatment reaction, and it can be known from the existing literature that the inorganic carbon source in the environment is often biological nitrogen removal. The limiting factor of the reaction, and increasing the amount of inorganic carbon sources within a specific range helps the reaction rate of biological nitrogen removal; therefore, in order to maintain the nitrogen removal efficiency of the traditional biological nitrogen removal system, the main cost comes from maintaining the environmental alkalinity in the system Maintenance, inorganic carbon source supply, organic carbon source supply, and the cost of chemicals for the conditioning of derived sludge, as well as the cost of site space caused by the addition of equipment to improve the efficiency of biological treatment. Therefore, how to improve the efficiency of the biological nitrogen removal system and reduce the operating cost at the same time needs to be further solved.

In order to overcome the above-mentioned technical problems, the purpose of the present invention is to provide a biological nitrogen removal system for nitrogen-containing sewage and a nitrogen removal method thereof. and a treated water storage tank, wherein the pre-aeration treatment section includes a pre-aeration tank, and the pre-aeration tank is provided with an aeration component and a pH value monitor electrically controlled by the control processor; thereby, the present invention The nitrogen removal method is to pre-aerate the nitrogenous sewage before the biological nitrogen removal treatment process to increase the inorganic carbon concentration and acid-base buffer substances in the water, which are used to supplement the consumption of the back-end biological nitrogen removal treatment process. Inorganic carbon and alkalinity, to improve the treatment efficiency of biological nitrogen removal system and reduce operating costs at the same time.

The reason is that in order to achieve the above purpose, the present invention provides a biological nitrogen removal system for nitrogen-containing sewage, which includes: a control processor; a pre-aeration treatment section, which includes a pre-aeration tank and an aeration component and a pH monitor, the pH monitor is electrically controlled by the control processor; the nitrogen-containing sewage is input into the pre-aeration treatment section, and the pre-aerated sewage is output after pre-aeration treatment; the biological nitrogen removal treatment section is After the pre-exposure treatment section according to the sewage treatment process, the biological nitrogen removal treatment section includes at least one biological treatment unit and a solid-liquid separation unit; the biological nitrogen removal treatment section is inputted into the pre-exposure sewage to undergo biological nitrogen removal treatment. The treated water is output after the treatment; the treated water storage tank is set after the biological nitrogen removal treatment section according to the sewage treatment process; the treated water storage tank is made to input and store the treated water; thereby, the control processor monitors the pH value through the The instrument monitors the pH value change data of the nitrogen-containing sewage during the pre-aeration treatment process, and the control processor controls the aeration time and aeration amount of the aeration component according to the pH value change data, so that the water in the nitrogen-containing sewage is The inorganic carbon concentration and acid-base buffer substances are increased through the aeration operation of the pre-aeration treatment section.

In the biological nitrogen removal system for nitrogen-containing sewage of the present invention, the pre-aeration treatment section is also provided with an alkalinity adjustment device, and the alkalinity adjustment device includes an alkali agent tank and an alkalinity monitor. The alkali agent tank and the pre-aeration The tank is connected, and the alkalinity monitor is set inside the pre-aeration tank; and the alkalinity monitor is electrically controlled by the control processor; whereby the control processor passes through the pH monitor and the alkalinity The pH monitor monitors the pH value and alkalinity change data of the nitrogen-containing sewage during the pre-aeration treatment process, and the control processor controls the aeration time and aeration amount of the aeration component according to the pH value change data, and according to the pH value change data. The alkalinity change data controls the alkali agent flow rate output by the alkali agent tank, so that the inorganic carbon concentration and acid-base buffer substances in the nitrogen-containing wastewater are increased through the aeration operation and alkalinity adjustment of the pre-aeration treatment section.

In the biological nitrogen removal system for nitrogen-containing sewage of the present invention, the treated water storage tank is also provided with a nitrogen monitoring device electrically controlled by the control processor; the control processor monitors the treated water storage tank through the nitrogen monitoring device The nitrogen content of the internal treated water, and the control processor controls the treated water storage tank to output treated water and return it to the biological removal device according to the nitrogen content data of the treated water when the nitrogen content data is higher than a preset value. The nitrogen treatment section is reprocessed.

In the biological nitrogen removal system for nitrogen-containing sewage of the present invention, the aeration component is selected from a coarse-bubble diffuser, a fine-bubble diffuser, or a jet aeration device.

In the biological nitrogen removal system for nitrogen-containing sewage of the present invention, the operating aeration rate of the pre-aeration treatment section is defined as the average air supply per ton of water, and the value of the average air supply is greater than 0.4 m ³ Air/ m ³ water/min ; preferably 0.4-3.0 m ³ Air/m ³ water/min.

In the biological nitrogen removal system for nitrogen-containing sewage of the present invention, the average residence time of the nitrogen-containing sewage in the pre-exposure treatment section is greater than or equal to 2 hours; preferably, 2-16 hours.

In the biological nitrogen removal system for nitrogen-containing sewage of the present invention, the operating pH value range of the nitrogen-containing sewage in the pre-exposure treatment section is 8 to 12 (8≦pH value≦12).

In the biological nitrogen removal system for nitrogen-containing sewage of the present invention, the operating alkalinity of the nitrogen-containing sewage in the pre-exposure treatment section is in the range of 200-1500 mg-CaCO ₃ /L (equivalent to 200 mg-CaCO 3 /L per liter of nitrogen-containing sewage). ~1500 mg- CaCO ₃ alkalinity)

In the biological nitrogen removal system for nitrogen-containing sewage of the present invention, the treated water storage tank is provided with a nitrogen monitoring device, and the nitrogen monitoring device is electrically controlled by the control processor to monitor the nitrogen content of the treated water; When the nitrogen content of the treated water exceeds a preset value, the control processor controls the treated water in the treated water storage tank to return to the biological nitrogen removal treatment section.

The present invention further provides a biological nitrogen removal method for nitrogen-containing sewage, the method steps comprising:

Pre-aeration treatment step: perform pre-aeration treatment on nitrogen-containing sewage to increase the concentration of inorganic carbon and acid-base buffer substances in the nitrogen-containing sewage; stop when the pH and alkalinity of the nitrogen-containing sewage reach preset values. Aeration to form pre-aerated sewage;

Biological nitrogen removal treatment step: the pre-aerated sewage is output from the pre-aeration tank to the biological nitrogen removal treatment section for biological nitrogen removal to form treated water;

Processed water monitoring step: outputting the treated water from the biological nitrogen removal treatment section to a treated water storage tank.

Regarding the techniques, means and other effects adopted by the present invention to achieve the above-mentioned objects, preferred feasible embodiments are given and described in detail in conjunction with the drawings as follows.

In order to facilitate the understanding of the present invention, the following description is given in conjunction with the embodiments.

Some embodiments of the features and advantages of the present invention are set forth in detail in the following description. It should be understood that the present invention can have various changes in different aspects without departing from the scope of the present invention, and the descriptions and drawings therein are essentially used for illustration rather than limitation this invention.

As shown in FIG. 1, the biological nitrogen removal system for nitrogen-containing sewage of the present invention includes a control processor 10, a nitrogen-containing sewage storage tank 20, a pre-exposure treatment section 30, a biological nitrogen removal treatment section 40, and a treatment section 40 arranged in the sequence of the sewage treatment process. The water storage tank 50; wherein, the control processor 10 is used to electrically control the composition of the system according to a preset program or manual input instructions, so as to achieve the control operation of parameters such as sewage flow and the amount of chemical added, and to detect water-related parameters (for example: pH value, alkalinity value, etc.); the nitrogen-containing sewage storage tank 20 is used to store and output nitrogen-containing sewage a to the pre-aeration treatment section 30, and the nitrogen-containing sewage a is pre-aerated in the pre-aeration treatment section 30 to form a pre-aeration treatment The sewage b is output to the biological nitrogen removal treatment section 40 , and the pre-exposed sewage b undergoes biological nitrogen removal through the biological nitrogen removal treatment section 40 to form treated water c and output to the treated water storage tank 50 .

In the biological nitrogen removal system for nitrogen-containing sewage of the present invention, the nitrogen-containing sewage storage tank 20 can be installed or deleted according to operational requirements. When the nitrogen-containing sewage storage tank 20 is deleted from the system of the present invention, the nitrogen-containing sewage a can be directly stored in In the pre-aeration tank 301 of the pre-aeration treatment section 30, pre-aeration is carried out in batches, and then biological nitrogen removal treatment is carried out.

As shown in FIG. 1 , a schematic diagram of the implementation of the nitrogen-containing sewage storage tank 20 in the biological nitrogen removal system for nitrogen-containing sewage of the present invention is shown, wherein the pre-aeration treatment section 30 includes a pre-aeration tank 301 and an alkalinity adjustment device. 302, the pre-aeration tank 301 is provided with an aeration assembly 31 at the bottom of the tank and a pH monitor 32 kept immersed in the water body, the aeration assembly 31 and the pH monitor 32 are controlled by the control processor 10. Electrical control, the alkalinity adjusting device 302 includes an alkali agent tank 33, a control valve 34 and an alkalinity monitor 35, a pipeline is connected between the alkali agent tank 33 and the pre-aeration tank 301, and a pipe is provided on the pipe. There is the control valve 34 electrically controlled by the control processor 10; the nitrogen-containing sewage a is input to the pre-aeration treatment section 30, the nitrogen-containing sewage a is subjected to pre-aeration treatment by the aeration component 31, and the After the alkalinity adjusting device 302 adjusts the alkalinity, the pre-exposed sewage b is output.

More specifically, in the embodiment of the present invention, as shown in FIG. 1 , the alkalinity adjusting device 302 includes an alkali agent tank 33 , a control valve 34 and an alkalinity monitor 35 , wherein the control valve 34 and the alkalinity monitor 35 The monitor 35 is electrically controlled by the control processor 10 ; the alkaline agent tank 33 communicates with the pre-aeration tank 301 , and the control valve 34 is provided on the pipeline connecting the alkaline agent tank 33 with the pre-aeration tank 301 , the control valve 34 is for the control processor 10 to regulate the flow rate of the alkali agent e output from the alkali agent tank 33, and the alkalinity monitor 35 is set in the pre-aeration tank 301 for real-time detection of the nitrogen-containing sewage aDynamic changes in alkalinity during aeration. Thereby, the control processor 10 uses the pH value monitor 32 and the alkalinity monitor 35 to detect and obtain the pH value and alkalinity change data of the nitrogen-containing sewage a during the aeration process, so as to electrically control the aeration process according to the data. The aeration time and aeration amount of the air component 31, and the opening or closing of the control valve 34 is electrically controlled according to these data, so as to achieve the purpose of adjusting the pH value and alkalinity of the nitrogen-containing sewage a.

In the embodiment of the present invention, the aeration component 31 can be selected from a coarse bubble diffuser, a fine bubble diffuser, or a jet aeration device.

Preferably, the operating aeration volume of the pre-aeration treatment section 30 is defined as the average air supply volume per ton of water, and the value of the average air supply volume is greater than 0.4 m ³ Air/m ³ water/min; preferably 0.4-3.0 m ³ Air/m ³ water/min.

Preferably, the average residence time of the nitrogen-containing sewage a in the pre-exposure treatment section 30 is greater than or equal to 2 hours; preferably, 2-16 hours.

Preferably, the operating pH value of the nitrogen-containing sewage a in the pre-exposure treatment section 30 is in the range of 8 to 12 (8≦pH value≦12).

Preferably, the operating alkalinity equivalent range of the nitrogen-containing sewage a in the pre-exposure treatment section 30 is 200-1500 mg-CaCO ₃ /L (each liter of nitrogen-containing sewage a contains equivalent to 200-1500 mg-CaCO _{3 .} alkalinity).

As shown in FIG. 1 , the biological nitrogen removal treatment section 40 is arranged after the pre-exposure treatment section 30 according to the sewage treatment process; the biological nitrogen removal treatment section 40 includes at least a biological treatment unit and a solid-liquid separation unit; The biological nitrogen removal treatment section 40 inputs the pre-exposed sewage b, and outputs the treated water c after the biological nitrogen removal treatment.

As shown in FIG. 1 , the treated water storage tank 50 is installed after the biological nitrogen removal treatment section 40 according to the sewage treatment process. The treated water storage tank 50 is provided with a nitrogen monitoring device 51 immersed in the water body. The monitoring device 51 is electrically controlled by the control processor 10 to monitor the nitrogen content of the treated water c; the control processor 10 monitors the nitrogen content of the treated water c inside the treated water storage tank 50 through the nitrogen monitoring device 51 , and the control processor 10 controls the treated water storage tank 50 to output the treated water c back to the biological nitrogen removal treatment section 40 when the nitrogen content data is higher than the preset value according to the nitrogen content data of the treated water c. For reprocessing, for example, when the nitrogen content of the treated water c exceeds a preset value, the control processor 10 controls the treated water c in the treated water storage tank 50 to return to the biological nitrogen removal treatment section 40 . Among them, the above-mentioned preset value of nitrogen content for controlling the return flow of the treated water c is generally based on the local regulations, the needs of users, the bearing capacity of the downstream sewage system and other factors to select the operating parameters.

In the embodiment of the present invention, the nitrogen monitoring device 51 can be selected from a water ammonia (nitrogen) analyzer, a nitrate (nitrogen) analyzer or a total nitrogen analyzer, to measure the nitrogen content in the treated water c, and output The nitrogen content data measured in real time is sent to the control processor 10 as the basis for the control processor 10 to judge whether the nitrogen content of the treated water c is qualified (for example, the monitoring range of a general instrument is the nitrogen content of 0-200 mg-N/L). , and for the control processor 10 to control the treated water c to return to the biological nitrogen removal treatment section 40 for further treatment when the measured nitrogen content of the treated water c exceeds a preset value.

In addition, in the embodiment of the present invention, each section of the tank body is provided with at least two control valves (not shown) for controlling the input and output of each section of the water body, and these control valves are electrically controlled by the control processor 10 Control switch.

More specifically, the control valve mentioned in the biological nitrogen removal system for nitrogen-containing sewage of the present invention can be replaced by a pump, and the pump starts when a preset condition is reached, and stops when the preset condition is reached to achieve the purpose of flow control. In addition, the biological nitrogen removal system for nitrogen-containing sewage of the present invention can also achieve the purpose of flow control by other known non-control valve and pump methods.

Therefore, the biological nitrogen removal system for nitrogen-containing sewage of the present invention utilizes the control processor 10 to receive the pH value monitor 32 to monitor the pH value change data of the nitrogen-containing sewage a during the pre-aeration treatment process, and then controls the The processor 10 controls the aeration time and aeration amount of the aeration component 31 according to the pH value change data, so that the inorganic carbon concentration and acid-base buffer substances in the water of the nitrogen-containing sewage a pass through the aeration of the pre-aeration treatment section 30 increase by operation.

According to the existing literature and the description of the background art, the biological nitrogen removal reaction process will consume inorganic carbon and alkalinity, so the inorganic carbon source in the environment is usually the limiting factor of the biological nitrogen removal reaction. Therefore, according to the biological nitrogen removal to be carried out. The composition of nitrogen-containing sewage a and/or the selected biological nitrogen removal reaction will increase the inorganic carbon source content in nitrogen-containing sewage a within a reasonable range, which will help the rate of biological nitrogen removal reaction. Furthermore, the existing equipment needs to effectively improve the reaction rate of biological nitrogen removal, but it cannot effectively improve the efficiency of the biological nitrogen removal system and reduce the operating cost by expanding the land space required for the biological nitrogen removal reaction. And to achieve the purpose of reducing the use of space.

The aforementioned reduction in operating costs includes reducing the amount of chemicals required to maintain or improve the efficiency of the biological nitrogen removal reaction, such as reducing the amount of baking soda or soda ash input in the biological nitrogen removal treatment section, and reducing the biological nitrogen removal reaction efficiency. and additional space.

In the biological nitrogen removal system for nitrogen-containing sewage of the present invention, the pre-aeration treatment section 30 can be adjusted by using the alkalinity (organic alkali and/or inorganic alkali) contained in the nitrogen-containing sewage a itself during the aeration process or by adjusting the alkalinity. The device 302 achieves the purpose of increasing the inorganic alkalinity in the nitrogen-containing sewage a by adding an alkali agent e externally.

More specifically, the principle of adjusting the pH value of the nitrogen-containing sewage a by the biological nitrogen removal system of the nitrogen-containing sewage of the present invention is that before the nitrogen-containing sewage a is subjected to the biological nitrogen removal treatment, aeration is performed in the pre-aeration treatment section 30 in advance, _{The carbon dioxide (CO 2} ) output from the aeration assembly 31 is absorbed into the nitrogen-containing sewage a, thereby converting the caustic alkalinity [OH ⁻ ] in the nitrogen-containing sewage a into the inorganic alkalinity to which the inorganic carbon belongs: bicarbonate ion [HCO ₃ ^- ] and carbonate ions [CO ₃ ^2- ], so as to achieve the effect of preserving the alkalinity in the system and increasing the inorganic carbon source in the process.

Therefore, in the embodiment of the biological nitrogen removal system for nitrogen-containing sewage of the present invention, the nitrogen-containing sewage a can be aerated only by using the pre-aeration tank 301 of the pre-aeration treatment section 30 before the biological nitrogen removal treatment section 40 , to achieve the purpose of adjusting the pH value and alkalinity of nitrogen-containing sewage a; it is also possible to use the pre-aeration tank 301 of the pre-aeration treatment section 30 between the biological nitrogen removal treatment sections 40 for aeration, and at the same time cooperate with the alkalinity adjustment device. 302 Adjust the pH value and alkalinity of the nitrogen-containing sewage a that fails to reach the preset pH value and alkalinity after pre-aeration, so as to ensure the reaction efficiency of the nitrogen-containing sewage a in the biological nitrogen removal treatment section 40 .

When the pre-aeration treatment section 30 of the biological nitrogen removal system for nitrogen-containing sewage of the present invention is only provided with a pre-aeration tank 301, after the nitrogen-containing sewage a is input to the pre-aeration treatment section 30, the control processor 10 passes through the pH value The monitor 32 monitors the dynamic changes of the pH value and alkalinity of the nitrogen-containing sewage a from the beginning to the end of the pre-aeration in real time, and controls the aeration time and aeration amount accordingly, until the pH value and the alkalinity of the nitrogen-containing sewage a reach the range of The preset value of the control processor 10.

When the pre-aeration treatment section 30 of the biological nitrogen removal system for nitrogen-containing sewage of the present invention is simultaneously provided with a pre-aeration tank 301 and an alkalinity adjustment device 302, after the nitrogen-containing sewage a is input to the pre-aeration treatment section 30, it will be controlled by The processor 10 monitors the dynamic changes of the pH value and alkalinity of the nitrogen-containing sewage a from the beginning to the end of the pre-aeration in real time through the pH value monitor 32 and the alkalinity monitor 35, and controls the aeration time, aeration amount and alkalinity accordingly. The input amount of the agent e is adjusted until the pH value and alkalinity of the nitrogen-containing sewage a reach the preset values in the control processor 10 .

In the embodiment of the present invention, the preset values of pH and alkalinity in the control processor 10 may be manually input to the control processor 10 or automatically generated by the control processor 10 according to a built-in program.

According to the above, the biological nitrogen removal system for nitrogen-containing wastewater of the present invention is particularly suitable for treating wastewater that is alkaline in nature, such as wastewater rich in tetramethylammonium hydroxide (TMAH) or monoethanolamine (MEA) from high-tech photovoltaic power plants. ) waste water; this kind of alkaline waste water can effectively reduce the useless alkalinity caused by the use of acid agent to adjust the pH value of sewage before the waste water enters the biological nitrogen removal treatment process. wasted.

Please also refer to FIG. 2 to FIG. 7 , the biological nitrogen removal treatment section 40 of the biological nitrogen removal system for nitrogen-containing sewage of the present invention can be selected from the anaerobic-aerobic treatment method (Anoxic-Oxic system, or MLE method), good Oxygen-anaerobic treatment system (Oxic-Anoxic system) or anaerobic ammonium nitrogen oxidation (Anammox system).

Among them, as shown in Fig. 2 and Fig. 3, the biological nitrogen removal system for nitrogen-containing sewage of the present invention adopts two implementations of the aerobic-anaerobic treatment system (Oxic-Anoxic system). Among them, the biological nitrogen removal reaction tank 41 as shown in FIG. 2 is provided with a biological nitrogen removal device 40A, which sequentially includes an aerobic treatment unit A1, an anaerobic treatment unit A2 and a precipitation unit A3 according to the processing flow of the biological nitrogen removal device 40A; The biological nitrogen removal reaction tank 41 as shown in FIG. 3 is provided with a biological nitrogen removal device 40B. According to the processing flow of the biological nitrogen removal device 40B, the biological nitrogen removal device 40B includes an aerobic treatment unit B1, an anaerobic treatment unit B2 and a pressurized floatation unit B3 in sequence. .

Among them, as shown in FIG. 4 , it is shown that the biological nitrogen removal system of the present invention adopts the anaerobic-aerobic treatment method (Anoxic-Oxic system). The biological nitrogen removal reaction tank 41 as shown in FIG. 4 is provided with a biological nitrogen removal device 40C. According to the processing flow of the biological nitrogen removal device 40C, the biological nitrogen removal device 40C includes an anaerobic treatment unit C1, an aerobic treatment unit C2 and a precipitation unit C3 in sequence; as shown in the figure The biological nitrogen removal reaction tank 41 of 5 is provided with a biological nitrogen removal device 40F, which sequentially includes an anaerobic treatment unit F1, an aerobic treatment unit F2 and a membrane filtration unit F3 according to the processing flow of the biological nitrogen removal device 40F.

Among them, as shown in Fig. 6 and Fig. 7 , two implementations of the anaerobic ammonium nitrogen oxidation method (Anammox system) are shown in the biological nitrogen removal system for nitrogen-containing sewage of the present invention. Among them, the biological nitrogen removal reaction tank 41 as shown in FIG. 6 is provided with a biological nitrogen removal device 40D, which includes a short-range nitrification unit D1, an anaerobic ammonia nitrogen oxidation unit D2 and a precipitation unit D3 in sequence according to the processing flow of the biological nitrogen removal device 40D; The biological nitrogen removal reaction tank 41 as shown in FIG. 7 is provided with a biological nitrogen removal device 40E. According to the processing flow of the biological nitrogen removal device 40E, the biological nitrogen removal device 40E includes a short-range nitrification and anaerobic ammonium nitrogen oxidation unit E1 and a precipitation unit E2 in sequence.

In an embodiment of the present invention, each of the biological nitrogen removal devices (40A, 40B, 40C, 40D, 40E, 40F) is installed in a biological nitrogen removal reaction tank 41 to perform the biological nitrogen removal treatment process. It should be understood that the directions of the arrows in FIGS. 2 to 7 are only used to represent the sequence of the processing flow, and are not used to limit the arrangement of each processing unit in the biological nitrogen removal reaction tank 41 , that is, in each biological nitrogen removal reaction tank 41. The treatment units can be arranged vertically according to the actual treatment requirements, so that the sewage flows from top to bottom for biological treatment, or can be arranged horizontally, so that the sewage flows through each treatment unit on the same level for biological treatment. In a stepped arrangement, the sewage flows through each treatment unit one by one to complete the biological treatment process.

In the embodiments of the present invention, the processing procedure of the biological nitrogen removal device of each embodiment mainly includes at least one biological nitrogen removal reaction unit and a solid-liquid separation procedure arranged in the last step. Wherein, the biological nitrogen removal reaction unit can be selected from anaerobic treatment unit, aerobic treatment unit, short-range nitrification unit, anaerobic ammonium nitrogen oxidation unit, short-range nitrification and anaerobic ammonium nitrogen oxidation unit according to the processing requirements, but not limited to this, select Combine the most appropriate biological nitrogen removal reaction units and their reaction sequences. Among them, the solid-liquid separation procedure can select different solid-liquid separation units according to different biological nitrogen removal methods, such as precipitation unit, pressurized floatation unit, membrane filtration unit, etc., but not limited to this, in order to achieve the purpose of solid-liquid separation .

The biological nitrogen removal system for nitrogen-containing sewage of the present invention has been described above. Please refer to FIG. 1 again for the description of the biological nitrogen removal method of the system:

The present invention provides a biological nitrogen removal method for nitrogen-containing sewage, the method steps comprising:

The step of providing nitrogen-containing sewage a: the nitrogen-containing sewage a is input and stored in the nitrogen-containing sewage storage tank 20;

Pre-aeration treatment step: the nitrogen-containing sewage a is output from the nitrogen-containing sewage storage tank 20 to the pre-aeration tank 301 for pre-aeration treatment, so as to increase the inorganic carbon concentration and acid-base buffer substances in the nitrogen-containing sewage a. ; Stop the aeration when the pH value and alkalinity of the nitrogen-containing sewage a reach the preset values to form pre-aerated sewage b;

The biological nitrogen removal treatment step: the pre-aerated sewage b is output from the pre-aeration tank 301 to the biological nitrogen removal treatment section 40 for biological nitrogen removal to form treated water c;

The step of monitoring the treated water c: the treated water c is output from the biological nitrogen removal treatment section 40 to the treated water storage tank 50 .

The above describes the implementation method of the biological nitrogen removal system for nitrogen-containing sewage and the nitrogen removal method of the present invention. Hereinafter, the developer wastewater of tetramethylammonium hydroxide (TMAH) taken from a wafer factory is used in the present invention. Test data of biological nitrogen removal by biological nitrogen removal system of nitrogenous sewage.

[Table 1] Raw water before aeration Aeration for 16 hours pH 12.2 9.1 total alkalinity 765 760 Inorganic carbon alkalinity 130.5 755 Inorganic carbon alkalinity ratio 17.1% 99.3%

10: Control Processor 20: Nitrogenous sewage storage tank 30: Pre-exposure processing section 301: Pre-aeration tank 31: Aeration components 32: pH Monitor 302: Alkalinity adjustment device 33: Alkali tank 34: Control valve 35: Alkalinity Monitor 40: Biological nitrogen removal treatment section 41: Biological nitrogen removal reaction tank 40A: Biological nitrogen removal device A1: Aerobic treatment unit A2: Anaerobic treatment unit A3: Precipitation unit 40B: Biological nitrogen removal device B1: Aerobic Treatment Unit B2: Anaerobic treatment unit B3: Pressurized float unit 40C: Biological nitrogen removal device C1: Anaerobic treatment unit C2: Aerobic Treatment Unit C3: Precipitation unit 40D: Biological nitrogen removal device D1: Short-path nitrification unit D2: Anaerobic ammonium nitrogen oxidation unit D3: Precipitation unit 40E: Biological nitrogen removal device E1: Short-range nitrification and anaerobic ammonium nitrogen oxidation unit E2: Precipitation unit 40F: Biological Nitrogen Removal Unit F1: Anaerobic treatment unit F2: Aerobic Treatment Unit F3: Membrane filter unit 50: Treated Water Storage Tank 51: Nitrogen Monitoring Device a: Nitrogenous sewage b: Pre-exposed sewage c: Treated water d: return water e: alkaline agent

Fig. 1 is the schematic diagram of the biological nitrogen removal system of nitrogenous sewage of the present invention; 2 is a schematic diagram of the implementation (1) of the biological nitrogen removal treatment section of the biological nitrogen removal system for nitrogen-containing sewage according to the present invention; 3 is a schematic diagram of the implementation (2) of the biological nitrogen removal treatment section of the biological nitrogen removal system for nitrogen-containing sewage according to the present invention; 4 is a schematic diagram of the implementation (3) of the biological nitrogen removal treatment section of the biological nitrogen removal system for nitrogen-containing sewage according to the present invention; 5 is a schematic diagram of the implementation (4) of the biological nitrogen removal treatment section of the biological nitrogen removal system for nitrogen-containing sewage according to the present invention; 6 is a schematic diagram of the implementation (5) of the biological nitrogen removal treatment section of the biological nitrogen removal system for nitrogen-containing sewage according to the present invention; FIG. 7 is a schematic diagram of the implementation (6) of the biological nitrogen removal treatment section of the biological nitrogen removal system for nitrogen-containing sewage according to the present invention.

10: Control Processor

20: Nitrogenous sewage storage tank

30: Pre-exposure processing section

301: Pre-aeration tank

31: Aeration components

32: pH Monitor

302: Alkalinity adjustment device

33: Alkali tank

34: Control valve

35: Alkalinity Monitor

40: Biological nitrogen removal treatment section

50: Treated Water Storage Tank

51: Nitrogen Monitoring Device

a: Nitrogenous sewage

b: Pre-exposed sewage

c: Treated water

d: return water

e: alkaline agent

Claims (9)

A biological nitrogen removal system for nitrogen-containing sewage, which includes: a control processor; a pre-aeration treatment section, which includes a pre-aeration tank, an aeration component and a pH monitor inside the pre-aeration tank, the pH monitor is subject to The control processor is electrically controlled; the nitrogen-containing sewage is input into the pre-aeration treatment section, and the pre-aerated sewage is output after pre-aeration treatment; the biological nitrogen removal treatment section is set after the pre-aeration treatment section according to the sewage treatment process , the biological nitrogen removal treatment section includes at least one biological treatment unit and a solid-liquid separation unit; the biological nitrogen removal treatment section is made to input the pre-exposed sewage, and after the biological nitrogen removal treatment, the treated water is output; the treated water storage tank is The sewage treatment process is set after the biological nitrogen removal treatment section; the treated water storage tank is made to input and store the treated water; thereby, the control processor monitors the nitrogen-containing sewage in the pre-aeration treatment process through the pH value monitor The pH value change data, and the control processor controls the aeration time and aeration amount of the aeration component according to the pH value change data, so that the inorganic carbon concentration and acid-base buffer substances in the water of the nitrogen-containing sewage pass through the pre-aeration The aeration operation of the treatment section is increased, and the treated water storage tank is also provided with a nitrogen monitoring device electrically controlled by the control processor; the control processor monitors the treated water inside the treated water storage tank through the nitrogen monitoring device. and the control processor controls the output of the treated water storage tank to return the treated water to the biological nitrogen removal treatment section when the nitrogen content data is higher than the preset value according to the nitrogen content data of the treated water. deal with. The biological nitrogen removal system for nitrogen-containing sewage as described in item 1 of the scope of the patent application, wherein the pre-exposure treatment section is further provided with an alkalinity adjusting device, and the alkalinity adjusting device includes an alkali agent tank and an alkalinity monitor. A measuring instrument, the alkali agent tank is communicated with the pre-aeration tank, the alkalinity monitor is set inside the pre-aeration tank; and the alkalinity monitor is electrically controlled by the control processor; The control processor monitors the pH value and alkalinity change data of the nitrogen-containing sewage in the pre-aeration treatment process through the pH value monitor and the alkalinity monitor, and the control processor controls the aeration according to the pH value change data The aeration time and aeration volume of the component, and the alkali agent flow rate output by the alkali agent tank is controlled according to the alkalinity change data, so that the inorganic carbon concentration and acid-base buffer substances in the water of the nitrogen-containing sewage pass through the pre-aeration treatment section. Aeration operation and alkalinity adjustment are increased, and the treated water storage tank is also provided with a nitrogen monitoring device that is electrically controlled by the control processor; the control processor monitors the treatment inside the treated water storage tank through the nitrogen monitoring device. The nitrogen content of the water, and the control processor controls the treated water storage tank to output the treated water and return it to the biological nitrogen removal treatment section according to the nitrogen content data of the treated water when the nitrogen content data is higher than the preset value Reprocess. The biological nitrogen removal system for nitrogen-containing sewage as described in item 1 or 2 of the patent application scope, wherein, the aeration component is selected from a coarse air bubble diffuser, a fine air bubble diffuser, or a jet aeration device. According to the biological nitrogen removal system for nitrogen-containing sewage described in item 1 or 2 of the scope of application, the operating aeration rate of the pre-aeration treatment section is defined as the average air supply per ton of water, and the value of the average air supply is greater than 0.4-3.0m ³ Air/m ³ water/min. The biological nitrogen removal system for nitrogen-containing sewage as described in item 1 or 2 of the patent application scope, wherein the average residence time of the nitrogen-containing sewage in the pre-exposure treatment section is 2-16 hours. The biological nitrogen removal system for nitrogen-containing sewage as described in claim 1 or 2, wherein the operating pH value of the nitrogen-containing sewage in the pre-exposure treatment section ranges from 8 to 12. The biological nitrogen removal system for nitrogen-containing sewage as described in item 1 or 2 of the patent application scope, wherein the operating equivalent alkalinity of the nitrogen-containing sewage in the pre-exposure treatment section ranges from 200 to 1500 mg-CaCO ₃ /L. The biological nitrogen removal system for nitrogen-containing sewage as described in item 1 or 2 of the scope of the patent application, wherein a nitrogen monitoring device is arranged in the treated water storage tank, and the nitrogen monitoring device is electrically controlled by the control processor. to monitor the nitrogen content of the treated water; when the nitrogen content of the treated water exceeds a preset value, the control processor controls the treated water in the treated water storage tank to return to the biological nitrogen removal treatment section. A biological nitrogen removal method for nitrogen-containing sewage, the method steps include: a nitrogen-containing sewage supply step: inputting and storing the nitrogen-containing sewage in a pre-aeration tank; a pre-aeration treatment step: performing a pre-aeration treatment on the nitrogen-containing sewage, In order to improve the inorganic carbon concentration and acid-base buffer substances in the nitrogen-containing sewage; stop aeration when the pH value and alkalinity of the nitrogen-containing sewage reach the preset values to form pre-aerated sewage; biological nitrogen removal treatment steps: The pre-aerated sewage is output from the pre-aeration tank to the biological nitrogen removal treatment section for biological nitrogen removal to form treated water; Processed water monitoring step: outputting the treated water from the biological nitrogen removal treatment section to a treated water storage tank.

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