High-efficiency nitrification and denitrification wastewater treatment method based on separation of carbon and nitrogen elements in influent

Abstract

The invention provides a highly efficient nitrification and denitrification sewage treatment method based on the separation of carbon and nitrogen elements in the influent, comprising the following steps: S1: the raw sewage enters the carbon-nitrogen separator, and a high carbon adsorption mixed liquid is obtained at the bottom of the carbon-nitrogen separator; a high nitrogen separation clear liquid is obtained at the top of the carbon-nitrogen separator; S2: the high nitrogen separation clear liquid obtained in step S1 is subjected to denitrification reaction, nitrite / nitrification reaction in turn to obtain a nitrified liquid; S3: the high carbon adsorption mixed liquid and the nitrified liquid are subjected to denitrification reaction, anaerobic phosphorus release reaction, nitrification aerobic phosphorus absorption reaction in turn to obtain a solution to be precipitated; S4: the solution to be precipitated enters the sedimentation tank, and a part of the activated sludge obtained at the bottom of the sedimentation tank is directly discharged, and the other part enters the carbon-nitrogen separator in step S1, and the denitrification reaction in step S2 and step S3. The theoretical value of the denitrification rate of the present application is increased from 80% to more than 90%, and the TN of the effluent of the biochemical system can reach 5mg / L.

Description

Technical Field

[0001] The invention belongs to the field of sewage treatment, and in particular relates to a high-efficiency nitrification and denitrification sewage treatment method based on separation of carbon and nitrogen elements in influent. Background Art

[0002] Local standards for water pollutant discharge from urban sewage treatment plants have been promulgated in various parts of the country, raising the pollutant discharge limit. The denitrification rate of the activated sludge biochemical treatment process with traditional process configuration is about 80%. In order to meet the discharge standards, it is necessary to increase deep treatment, which increases investment and cost.

[0003] The activated sludge process achieves nitrogen removal through the nitrification-denitrification pathway. The biochemical unit often requires a longer SRT to meet the proliferation and retention of heterotrophic nitrifying bacteria, but the long SRT will increase the capacity of the main biological pool (aeration pool) and thus increase the engineering civil engineering investment.

[0004] The lack of carbon source is an important factor restricting the operation effect of traditional nitrogen removal and phosphorus removal processes. The effect of traditional activated sludge phosphorus removal and nitrogen removal is directly affected by the influent SCOD, especially the concentration of volatile fatty acids VFAs. The low influent C / N ratio and VFAs / P ratio are the basic characteristics of the influent water quality of most urban sewage treatment plants in China. The traditional process configuration design is not applicable or is not an economic choice in most areas of the country. The strict domestic N and P emission standards require the addition of a large amount of chemical phosphorus removal agents and denitrification carbon sources, resulting in high carbon emissions throughout the sewage treatment process. Summary of the invention

[0005] In view of this, the present invention aims to propose a highly efficient nitrification and denitrification wastewater treatment method based on separation of carbon and nitrogen elements in influent water, so as to solve at least one technical problem in the background technology.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] The highly efficient nitrification and denitrification wastewater treatment method based on the separation of carbon and nitrogen elements in the influent comprises the following steps:

[0008] S1: The raw sewage enters the carbon-nitrogen separator, and a high-carbon adsorption mixed liquid is obtained at the bottom of the carbon-nitrogen separator; a high-nitrogen separation clear liquid is obtained at the top of the carbon-nitrogen separator;

[0009] S2: the high-nitrogen separation clear liquid obtained in step S1 is subjected to a denitrification reaction to obtain a first reaction solution, and the first reaction solution is subjected to a nitrosation / nitrification reaction to obtain a nitrified liquid;

[0010] S3: the high carbon adsorption mixed solution obtained in step S1 and the nitrification solution obtained in step S2 are subjected to denitrification reaction to obtain a second reaction solution after the denitrification reaction, the second reaction solution is subjected to anaerobic phosphorus release reaction to obtain a third reaction solution after the anaerobic phosphorus release reaction, and the third reaction solution is subjected to nitrification and aerobic phosphorus absorption reaction to obtain a solution with precipitation;

[0011] S4: The solution to be precipitated obtained in step S3 enters a sedimentation tank, a part of the activated sludge obtained at the bottom of the sedimentation tank is directly discharged, and the other part enters the carbon-nitrogen separator in step S1, the denitrification reaction in step S2 and the denitrification reaction in step S3, and the supernatant obtained in the sedimentation tank is directly discharged.

[0012] Further, the high nitrogen separation clear liquid in step S2 is subjected to denitrification reaction, including the high nitrogen separation clear liquid obtained in step S1 being subjected to denitrification reaction in a first anoxic tank, obtaining a first reaction solution with high nitrogen and low carbon after the denitrification reaction, and the first reaction solution with high nitrogen and low carbon being subjected to nitrification / nitrification reaction in a first aerobic tank, obtaining a nitrified solution after the nitrification / nitrification reaction,

[0013] The first mixed solution obtained after the reaction in the first aerobic tank flows back to the first anoxic tank.

[0014] Furthermore, the BOD sludge load of the first aerobic tank is less than 0.1 gBOD5 / gMLVSS.d.

[0015] Furthermore, in step S2, the first reaction solution is subjected to nitrification / nitrification reaction in the first aerobic tank to obtain a nitrified solution;

[0016] Or the first reaction solution in step S2 undergoes nitrite / nitrification reaction in the first aerobic tank and then passes through the intermediate sedimentation tank to obtain nitrification liquid, a part of the sludge in the intermediate sedimentation tank enters the denitrification reaction in step S2 through the first sludge return pipe, and the other part flows back to the nitrification aerobic phosphorus absorption reaction in step S3.

[0017] Further, the first reaction solution in step S2 enters the first aerobic tank for nitrification / nitrification reaction to obtain a nitrified solution, and step S3 includes subjecting the high carbon adsorption mixed solution obtained in step S1 and the nitrified solution obtained in step S2 to denitrification in the second anoxic tank to obtain a second reaction solution after the denitrification reaction; the second reaction solution is subjected to an anaerobic phosphorus release reaction in an anaerobic tank to obtain a third reaction solution after the anaerobic phosphorus release reaction;

[0018] Or the first reaction solution in step S2 enters the first aerobic tank for nitrification / nitrification reaction, and then passes through the intermediate sedimentation tank to obtain a nitrified solution. Step S3 includes subjecting the high carbon adsorption mixed solution obtained in step S1 and the nitrified solution obtained in step S2 to denitrification in the second anoxic tank to obtain a second reaction solution after the denitrification reaction; the second reaction solution and the high carbon adsorption mixed solution obtained in step S1 are subjected to an anaerobic phosphorus release reaction in an anaerobic tank to obtain a third reaction solution after the anaerobic phosphorus release reaction.

[0019] Furthermore, the maximum dissolved oxygen concentration in the second anoxic tank is 0.5 mg / L.

[0020] Furthermore, the third reaction solution is subjected to a nitrification and aerobic phosphorus absorption reaction in the second aerobic tank, and a solution to be precipitated is obtained after the nitrification and aerobic phosphorus absorption reaction.

[0021] Furthermore, the second mixed solution obtained after the reaction in the second aerobic tank flows back to the second anoxic tank.

[0022] Furthermore, the dissolved oxygen concentration in the second aerobic tank is 0.5-1.5 mg / L.

[0023] Further, the bottom of the sedimentation tank is discharged through the first sludge pipe, and the bottom of the sedimentation tank is connected to the third sludge return pipe, the fourth sludge return pipe, and the fifth sludge return pipe respectively through the second sludge pipe;

[0024] The bottom of the sedimentation tank is connected to the carbon-nitrogen separator through the third sludge return pipe;

[0025] The bottom of the sedimentation tank transports the sludge to the denitrification reaction of the high-nitrogen separation clear liquid in step S2 through the fourth sludge return pipe;

[0026] The bottom of the sedimentation tank transports the sludge to the denitrification reaction of the high-carbon adsorption mixed liquid and the nitrification liquid in step S3 through the fifth sludge return pipe.

[0027] The return ratio of the first sludge pipe is 50~100%; the return ratio of the second sludge pipe is 5~15%:

[0028] The return ratios of the third sludge return pipe, the fourth sludge return pipe and the fifth sludge return pipe are 25-75%.

[0029] Compared with the prior art, the efficient nitrification and denitrification wastewater treatment method based on separation of carbon and nitrogen elements in influent according to the present invention has the following advantages:

[0030] 1. The theoretical value of denitrification rate of this application is increased from 80% to more than 90%, and the TN of the effluent from the biochemical system can reach 5 mg / L.

[0031] 2. The civil construction investment of the biochemical pool in this application is saved by more than 30%.

[0032] 3. The aeration energy consumption of this application is reduced by more than 15%.

[0033] 4. This application is mainly based on short-range nitrification and denitrification, saving 40% of carbon sources and reducing carbon emissions by more than 20%. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0035] Figure 1 This is a flow chart of the efficient nitrification and denitrification wastewater treatment method based on separation of carbon and nitrogen elements in influent according to Example 1 of the present invention;

[0036] Figure 2 This is a flow chart of the efficient nitrification and denitrification wastewater treatment method based on separation of carbon and nitrogen elements in influent according to Example 2 of the present invention;

[0037] Figure 3 This is a flow chart of Comparative Example 1 of the present invention.

[0038] Description of reference numerals:

[0039] 1. Carbon-nitrogen separator; 2. First anoxic tank; 3. First aerobic tank; 4. Intermediate sedimentation tank; 5. Second anoxic tank; 6. Anaerobic tank; 7. Second aerobic tank; 8. Sedimentation tank; 9. First sludge return pipe; 10. Second sludge return pipe; 11. First sludge pipe; 12. Second sludge pipe; 13. Third sludge return pipe; 14. Fourth sludge return pipe; 15. Fifth sludge return pipe; 16. Comparative anaerobic tank; 17. Comparative anoxic tank; 18. Comparative aerobic tank; 19. Comparative sedimentation tank. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0041] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0042] Explanation of the English abbreviations in this application:

[0043] SS is the suspended solids concentration, unit: mg / L;

[0044] COD is chemical oxygen demand;

[0045] TP is total phosphorus, which is the result of the determination after the water sample is digested and various forms of phosphorus are converted into orthophosphate, and is measured in milligrams of phosphorus per liter of water sample;

[0046] DO is dissolved oxygen, which refers to the amount of oxygen molecules dissolved in water, usually expressed in milligrams per liter (mg / L);

[0047] TN is total nitrogen, which represents the total amount of inorganic and organic nitrogen in various forms in water, expressed in milligrams of nitrogen per liter of water;

[0048] C / N is the carbon-nitrogen ratio, which refers to the ratio of the total carbon content to the total nitrogen content in organic matter;

[0049] F / M is the organic loading rate (or sludge load), F refers to organic matter and M refers to microorganisms.

[0050] COD cr The dichromate index is the dichromate value, also known as dichromate oxidizability or dichromate oxygen demand;

[0051] BOD5 is the amount of dissolved oxygen consumed by microbial metabolism;

[0052] NH3-N is an indicator of the ammonia nitrogen content in water (wastewater).

[0053] Example 1

[0054] Domestic sewage treatment project in a certain city, project scale: 50,000 m 3 / d, design water temperature: 12℃, design inlet and outlet water quality, see Table 1.

[0055] Table 1 Influent water quality table

[0056] .

[0057] like Figure 1 As shown, the high-efficiency nitrification and denitrification wastewater treatment process based on the separation of carbon and nitrogen elements in the influent consists of an adsorption separation section, a biochemical section (the first anoxic tank 2, the first aerobic tank 3) and a biochemical section (the second anoxic tank 5, the anaerobic tank 6, the second aerobic tank 7). The specific process is as follows:

[0058] The raw sewage and the return sludge are mixed and then enter the carbon-nitrogen separator 1. The return sludge uses its adsorption effect on pollutants to adsorb SS, COD and TP and clarify them, forming a high-carbon and low-nitrogen adsorption mixed liquid of about 80% SS, COD, total phosphorus and 25% TN. About 75% of the total nitrogen, 20% of COD, total phosphorus and SS are separated into a high-nitrogen and low-carbon clarified liquid, achieving a rough separation of nitrogen pollutants from other pollutants.

[0059] The raw sewage enters the carbon-nitrogen separator 1, and a high-carbon adsorption mixed liquid is obtained at the bottom of the carbon-nitrogen separator 1; a high-nitrogen separation clear liquid is obtained at the upper part of the carbon-nitrogen separator 1, and the high-nitrogen separation clear liquid undergoes a first reaction solution in the first anoxic tank 2; the first reaction solution of the first anoxic tank 2 enters the first aerobic tank 3: this is a denitrification and nitrite / nitrification process, and the high-nitrogen and low-carbon high-nitrogen separation clear liquid enters the first anoxic tank 2, and undergoes rapid denitrification with the sludge return and the first mixed solution of the first aerobic tank 3, and enters the first aerobic tank 3 after the carbon source is consumed, and the first reaction solution undergoes nitrite / nitrification reaction in the first aerobic tank 3 to form a mixed liquid.

[0060] The first aerobic tank 3 enters the intermediate sedimentation tank 4 for mud-water separation, and the separated nitrified liquid enters the second anoxic tank 5. The first sludge return pipe 9 of the intermediate sedimentation tank 4 returns to the first anoxic tank 2 for denitrification, and at the same time provides activated sludge with a high abundance of nitrite / nitrifying bacteria for the biochemical stage to achieve the proliferation and retention of nitrite / nitrifying bacteria. The nitrite / nitrate nitrogen contained in the first sludge return pipe 9, and the first sludge return pipe 9 consumes all the carbon sources in the high-nitrogen separation clear liquid in the first anoxic tank 2 for denitrification, which not only fully utilizes the carbon source, but also ensures that the proliferation of nitrite / nitrifying bacteria (autotrophic) in the first aerobic tank 3 is not affected by carbon oxidation (heterotrophic bacteria);

[0061] The second sludge return pipe 10 of the intermediate sedimentation tank 4 enters the second aerobic tank 7 to strengthen the nitrification / nitrification reaction of the second biochemical stage.

[0062] The high carbon adsorption mixed solution and the nitrification solution are subjected to denitrification reaction to obtain a second reaction solution, the second reaction solution is subjected to anaerobic phosphorus release reaction to obtain a third reaction solution, and the third reaction solution is subjected to nitrification aerobic phosphorus absorption reaction to obtain a solution with precipitation:

[0063] The high carbon adsorption mixed liquid is enriched with carbon source and is distributed to the second anoxic tank 5 and the anaerobic tank 6 as needed. In the second anoxic tank 5, the low DO nitrite / nitrification liquid and the high carbon adsorption mixed liquid are mixed and rapidly denitrified to obtain the second reaction solution. After the DO of the second reaction solution is exhausted, it enters the anaerobic tank 6 and reacts with part of the high carbon adsorption mixed liquid in the anaerobic zone. The polyphosphate bacteria release excessive phosphorus to obtain the third reaction solution. The anaerobic effluent of the third reaction solution enters the second aerobic tank 7 to further degrade the remaining carbon source substances and remove ammonia nitrogen by biological assimilation. If there is still residual ammonia nitrogen, the nitrifying bacteria carried by the second sludge return pipe 10 of the intermediate sedimentation tank 4 are used for nitrification.

[0064] The effluent from the second aerobic tank 7 enters the intermediate sedimentation tank 4 for mud-water separation, the third sludge return pipe 13 is sent to the carbon-nitrogen separator 1 for adsorption separation of SS and COD, the fourth sludge return pipe 14 and the fifth sludge return pipe 15 are sent to the first anoxic tank 2 and the second anoxic tank 5 to increase the system microbial concentration.

[0065] The sludge produced in the sedimentation tank 8 consists of the following four parts: a. Sludge converted from suspended solids SS in the influent (accounting for about 40%~65%); b. Sludge produced by the value-added of heterotrophic microorganisms in activated sludge (accounting for about 15%~30%); c. Activated sludge produced by endogenous attenuation of heterotrophic microorganisms (accounting for about 7%~15%); d. Sludge produced by the value-added of heterotrophic nitrifying bacteria (accounting for about 1~5%). The influent SS and carbon source of the first biochemical stage are very low (can be adjusted to less than 20% as needed), so the sludge production of the first three items can be less than 20% of the total sludge production, and the sludge production of the first biochemical stage can be less than 25% of the total sludge production of the system. Biological pool capacity = sludge age * sludge production, therefore, the aerobic pool capacity of the first biochemical stage, which uses less than 25% of the traditional process configuration, realizes the value-added and retention of nitrifying bacteria in the system, and completes the key step of sewage denitrification.

[0066] In the present application, the denitrification rate of the biochemical system is improved by adopting the reaction sequence of nitrification-denitrification-nitrification in combination with the reflux of the two-stage nitrification mixed liquid.

[0067] The low C / N conditions of this application can increase the proportion of nitrifying bacteria in activated sludge, thereby improving the efficiency of nitrification reaction. After carbon-nitrogen separation, the C / N of the clarified liquid is reduced to 15%~50% of the original sewage. Only when the BOD load is less than 0.15gBOD5 / gMLSS can the nitrification reaction proceed normally. In the first anoxic tank 2, the external carbon source is consumed by denitrification. Compared with the traditional process configuration, the sewage in the first aerobic tank 3 can skip the carbon oxidation stage and directly enter nitrification; the lower the C / N ratio, the higher the ratio of nitrifying bacteria in the activated sludge. When C / N=1:1, the proportion of nitrifying bacteria is about 3.8 times that of C / N=5:1. Therefore, the nitrification efficiency of the first aerobic tank 3 is much higher than that of the traditional process configuration design.

[0068] The low F / M ratio of the present application can improve the DO penetration of the biological flocs, thereby increasing the nitrification reaction rate.

[0069] In the activated sludge system dominated by nitrite, most of the nitrifying bacteria are inside the biological flocs. DO needs to pass through the biological flocs to be used by nitrifying bacteria, while carbon-containing organic matter increases DO consumption, reduces DO's penetration into the biological flocs, and reduces the nitrification reaction rate. On the contrary, under low F / M conditions, there are fewer carbon-containing organic matter, the oxygen consumption rate is low, and DO has strong penetration into the biological flocs, which can maintain a higher nitrification reaction rate. This process has a low C / N ratio, and with the sludge external reflow, the F / M is controlled at about 0.1 to improve the nitrification efficiency.

[0070] After eliminating the interference of carbon source, short-term nitrification and denitrification can be achieved, saving more than 15% of aeration and 40% of denitrification carbon source.

[0071] The DO of the first aerobic tank 3 is 0.3~0.7 mg / L, mainly nitrification; the DO of the second aerobic tank 7 is 0.5~1.5 mg / L. When the C / N ratio and F / M ratio are low, 1 mg / L DO can meet the nitrification demand, which not only reduces the aeration energy consumption, but also effectively reduces the waste of carbon source in the denitrification stage. The first anoxic tank 2-the first aerobic tank 3-the intermediate sedimentation tank 4-the second anoxic tank 5 creates conditions for short-range nitrification-denitrification, saving more than 15% of aeration volume and 40% of denitrification carbon source. High C / N ratio, high-efficiency denitrification reaction under low DO conditions.

[0072] In addition to water temperature, the most important factors affecting the denitrification rate are C / N ratio and DO. This process distributes the carbon source to the second anoxic tank 5 and the anaerobic tank 6 after adsorption, and the C / N ratio is high; because the DO of the nitrification liquid in the aerobic tank is about 1 mg / L, the return ratio from the second aerobic tank 7 to the second anoxic tank 5 is 0-100%, so the denitrification zone can achieve strict anoxic, and the denitrification reaction is more efficient; therefore, the anoxic denitrification tank capacity is smaller than the traditional process configuration, the sludge age and sludge volume are shown in Table 2, the process water quality parameters are shown in Table 3, the parameters of the biochemical system are shown in Table 4, and the return ratios of the second sludge pipe, the third sludge return pipe, and the fourth sludge return pipe are shown in Table 5.

[0073] Table 2 Mud age and mud volume

[0074] .

[0075] Table 3 Process water quality parameters, unit: mg / l

[0076] .

[0077] Table 4 Parameters of biochemical system

[0078] .

[0079] Table 5 Reflux ratio of the second sludge pipe, the third sludge return pipe, and the fourth sludge return pipe

[0080] .

[0081] The return sludge concentration of the sedimentation tank 8 in Example 1 is 10 gMLSS / L.

[0082] Example 2

[0083] like Figure 2As shown, the difference from Example 1 is that: the first aerobic tank 3 is connected to the intermediate settling tank 4 through a pipeline, the first reaction solution enters the first aerobic tank 3 for nitrite / nitrification reaction, and the mixed solution obtained passes through the intermediate settling tank 4 to obtain nitrified liquid; the nitrified liquid and the high carbon adsorption mixed solution undergo denitrification reaction; part of the sludge in the intermediate settling tank 4 enters the denitrification / nitrification reaction of the high nitrogen separation clear solution through the first sludge return pipe 9, and the other part enters the nitrification aerobic phosphorus absorption reaction of the nitrified liquid through the second sludge return pipe 10. And the high nitrogen adsorption mixed solution only enters the second anoxic tank 5, and does not enter the anaerobic tank 6.

[0084] In Example 2, a fixed filler with a specific surface area of ​​1000m 2 / m 3 , biological concentration 10000 mg / L, sludge age greater than 30 days, system sludge production 10360 kgDS / d, sedimentation tank 8 sludge concentration 10 gMLSS / L, water quality parameter table is shown in Table 6, biochemical tank parameters are shown in Table 7, the second sludge pipe 12, the third sludge return pipe 13, the fourth sludge return pipe 14, the fifth sludge return pipe 15, the second mixed solution, the first mixed solution reflux ratio is shown in Table 8.

[0085] Table 6 Water quality parameters, unit is mg / l

[0086] .

[0087] Table 7 Biochemical pool parameters

[0088] .

[0089] Table 8 Reflux ratio of the second sludge pipe 12, the third sludge return pipe 13, the fourth sludge return pipe 14, the fifth sludge return pipe 15, the second mixed solution, and the first mixed solution

[0090] .

[0091] Comparative Example 1:

[0092] The existing technologies for phosphorus and nitrogen removal from sewage are anaerobic, anoxic and aerobic (AAO, as follows Figure 3 ) and its variants, with AAO process as a comparative example. Figure 3 As shown;

[0093] The comparison anaerobic tank 16, the comparison anoxic tank 17, the comparison aerobic tank 18, and the comparison sedimentation tank 19 are connected in sequence through pipelines, the raw sewage is introduced into the comparison anaerobic tank 16, and the mixed liquid in the comparison aerobic tank 18 is returned to the comparison anoxic tank 17;

[0094] A part of the sludge in the comparative sedimentation tank 19 is discharged, and the other part enters the comparative anaerobic tank 16. The supernatant of the comparative sedimentation tank 19 is discharged.

[0095] Mud age and mud production: Mud age 15 days, mud production 11135kgDS / d.

[0096] Outlet water quality: except that TN is 12 mg / L, the rest are the same as Example 1 and Example 1. The parameters of the biochemical pool are shown in Table 9, the reflux ratios of sludge return and mixed liquor return are shown in Table 10, and the overall parameter comparison of Examples 1, 2 and Comparative Example 1 is shown in Table 11.

[0097] Table 9 Biochemical pool parameters

[0098] .

[0099] Table 10 Reflux ratio of sludge reflux and mixed liquor reflux

[0100] .

[0101] Table 11 Overall parameter comparison of Examples 1, 2 and Comparative Example 1

[0102] .

[0103] By comparing Example 1 and Example 2 with Comparative Example 1, it can be seen that the effluent TN of Example 1 and Example 2 is significantly less than that of Comparative Example 1, and the hydraulic retention time is short, the theoretical value of the denitrification rate is increased from 80% to more than 90%, and the effluent TN of the biochemical system can reach 5 mg / L; the civil construction investment of the biochemical pool is saved by more than 30% (the pool area of ​​Examples 1 and 2 is reduced compared with Comparative Example 1); the aeration energy consumption is reduced by more than 15%; short-range nitrification and denitrification are mainly used, and the carbon source is saved by 40%; and the carbon emission is reduced by more than 20%.

[0104] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A highly efficient nitrification and denitrification wastewater treatment method based on separation of carbon and nitrogen elements in influent, characterized by: The steps include: S1: The raw sewage enters the carbon-nitrogen separator, and a high-carbon adsorption mixed liquid is obtained at the bottom of the carbon-nitrogen separator; a high-nitrogen separation clear liquid is obtained at the top of the carbon-nitrogen separator; S2: the high-nitrogen separation clear liquid obtained in step S1 is subjected to a denitrification reaction to obtain a first reaction solution, and the first reaction solution is subjected to a nitrosation / nitrification reaction to obtain a nitrified liquid; S3: the high carbon adsorption mixed solution obtained in step S1 and the nitrification solution obtained in step S2 are subjected to denitrification reaction to obtain a second reaction solution after the denitrification reaction, the second reaction solution is subjected to anaerobic phosphorus release reaction to obtain a third reaction solution after the anaerobic phosphorus release reaction, and the third reaction solution is subjected to nitrification and aerobic phosphorus absorption reaction to obtain a solution to be precipitated; S4: The solution to be precipitated obtained in step S3 enters a sedimentation tank, a part of the activated sludge obtained at the bottom of the sedimentation tank is directly discharged, and the other part enters the carbon-nitrogen separator in step S1, the denitrification reaction in step S2 and the denitrification reaction in step S3, and the supernatant obtained in the sedimentation tank is directly discharged.

2. The method for treating wastewater by efficient nitrification and denitrification based on separation of carbon and nitrogen elements in influent according to claim 1, characterized in that: The high nitrogen separation clear liquid in step S2 is subjected to denitrification reaction, including the high nitrogen separation clear liquid obtained in step S1 being subjected to denitrification reaction in the first anoxic tank, obtaining a first reaction solution with high nitrogen and low carbon after the denitrification reaction, and the first reaction solution with high nitrogen and low carbon being subjected to nitrification / nitrification reaction in the first aerobic tank, obtaining a nitrified solution after the nitrification / nitrification reaction, The first mixed solution obtained after the reaction in the first aerobic tank flows back to the first anoxic tank.

3. The method for treating wastewater by efficient nitrification and denitrification based on separation of carbon and nitrogen elements in influent according to claim 2, characterized in that: The BOD sludge load of the first aerobic tank is less than 0.1gBOD5 / gMLVSS·d.

4. The method for treating wastewater by efficient nitrification and denitrification based on separation of carbon and nitrogen elements in influent according to claim 1, characterized in that: In step S2, the first reaction solution undergoes nitrification / nitrification reaction in the first aerobic tank to obtain a nitrified solution; Or the first reaction solution in step S2 undergoes nitrite / nitrification reaction in the first aerobic tank and then passes through the intermediate sedimentation tank to obtain nitrification liquid, a part of the sludge in the intermediate sedimentation tank enters the denitrification reaction in step S2 through the first sludge return pipe, and the other part flows back to the nitrification aerobic phosphorus absorption reaction in step S3.

5. The method for treating wastewater by efficient nitrification and denitrification based on separation of carbon and nitrogen elements in influent according to claim 1, characterized in that: The first reaction solution in step S2 enters the first aerobic tank for nitrification / nitrification reaction to obtain a nitrified solution. Step S3 includes subjecting the high carbon adsorption mixed solution obtained in step S1 and the nitrified solution obtained in step S2 to denitrification in the second anoxic tank to obtain a second reaction solution after the denitrification reaction. The second reaction solution is subjected to an anaerobic phosphorus release reaction in an anaerobic tank to obtain a third reaction solution after the anaerobic phosphorus release reaction. Or the first reaction solution in step S2 enters the first aerobic tank for nitrification / nitrification reaction, and then passes through the intermediate sedimentation tank to obtain a nitrified solution. Step S3 includes subjecting the high carbon adsorption mixed solution obtained in step S1 and the nitrified solution obtained in step S2 to denitrification in the second anoxic tank to obtain a second reaction solution after the denitrification reaction; the second reaction solution and the high carbon adsorption mixed solution obtained in step S1 are subjected to an anaerobic phosphorus release reaction in an anaerobic tank to obtain a third reaction solution after the anaerobic phosphorus release reaction.

6. The method for treating wastewater by efficient nitrification and denitrification based on separation of carbon and nitrogen elements in influent according to claim 5, characterized in that: The maximum dissolved oxygen concentration in the second anoxic tank is 0.5 mg / L.

7. The method for treating wastewater by efficient nitrification and denitrification based on separation of carbon and nitrogen elements in influent according to claim 1, characterized in that: The third reaction solution is subjected to a nitrification and aerobic phosphorus absorption reaction in the second aerobic tank, and a solution to be precipitated is obtained after the nitrification and aerobic phosphorus absorption reaction.

8. The method for treating wastewater by efficient nitrification and denitrification based on separation of carbon and nitrogen elements in influent according to claim 7, characterized in that: The second mixed solution obtained after the reaction in the second aerobic tank flows back to the second anoxic tank.

9. The method for treating wastewater by efficient nitrification and denitrification based on separation of carbon and nitrogen elements in influent according to claim 8, characterized in that: The dissolved oxygen concentration in the second aerobic tank is 0.5-1.5 mg / L.

10. The method for treating wastewater by efficient nitrification and denitrification based on separation of carbon and nitrogen elements in influent according to claim 1, characterized in that: The bottom of the sedimentation tank is discharged through the first sludge pipe, and the bottom of the sedimentation tank is connected to the third sludge return pipe, the fourth sludge return pipe, and the fifth sludge return pipe respectively through the second sludge pipe; The bottom of the sedimentation tank is connected to the carbon-nitrogen separator through the third sludge return pipe; The bottom of the sedimentation tank transports the sludge to the denitrification reaction of the high-nitrogen separation clear liquid in step S2 through the fourth sludge return pipe; The bottom of the sedimentation tank transports the sludge to the denitrification reaction of the high-carbon adsorption mixed liquid and the nitrification liquid in step S3 through the fifth sludge return pipe.

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