A suspended filler-driven sulfur autotrophic self-circulating deep denitrification process

Abstract

The present invention relates to the technical field of sewage treatment, and in particular to a suspended filler-driven sulfur autotrophic self-circulating deep denitrification process, comprising: adding a sulfur-iron composite carrier into an anoxic tank, and adding a modified polyurethane suspended filler into an aerobic tank; enriching sulfur autotrophic denitrifying bacteria and heterotrophic denitrifying bacteria on the sulfur-iron composite carrier located in the anoxic tank; injecting sewage filtered by a mechanical screen into a regulating tank and flowing through the regulating tank through the anoxic tank; testing the biofilm on the sulfur-iron composite carrier to determine the eligibility of the biofilm; enriching Anammox bacteria and short-range nitrifying bacteria on the modified polyurethane suspended filler located in the aerobic tank; testing the ATP concentration inside the biofilm on the modified polyurethane suspended filler to determine the eligibility of microbial metabolic activity; and determining whether the denitrification efficiency is qualified based on the total nitrogen concentration of the sewage after being treated in the regulating tank, the anoxic tank, and the aerobic tank. The present invention improves the stability of deep denitrification.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a suspended filler-driven sulfur autotrophic self-circulating deep denitrification process. Background Art

[0002] With increasing environmental protection requirements, deep denitrification technology for wastewater has become an important research area in the wastewater treatment field. Traditional denitrification processes rely primarily on heterotrophic denitrification, which requires an external organic carbon source. This not only increases operating costs but also may generate additional carbon emissions. Sulfur autotrophic denitrification technology, as a green and low-carbon wastewater denitrification method, utilizes sulfide as an electron donor and achieves nitrogen conversion and removal through the metabolism of autotrophic microorganisms.

[0003] Chinese patent application publication number: CN102910788A discloses a wastewater deep denitrification process, which specifically comprises the following steps: (1) microwave irradiation coagulation and precipitation, adding a certain amount of NaOH to high-concentration ammonia nitrogen wastewater and adjusting the pH value to 11-13, coagulating and precipitating the flocculant and the coagulant under alkaline conditions, and obtaining a supernatant after precipitation; (2) passing the supernatant obtained in step (1) into a stripping tower; a sprayer is provided at the top of the stripping tower, and a multi-layer packing layer is provided in the middle of the tower body, and the wastewater forms a fine liquid stream through the packing layer through the sprayer; at the same time, air is introduced into the aeration port at the bottom of the tower through a blower to achieve gas-liquid contact on the packing surface; and then the stripping tail gas is allowed to enter an absorption tank containing waste hydrochloric acid or waste sulfuric acid absorption liquid to absorb part of the ammonia nitrogen; (3) the pyrolysis product of magnesium ammonium phosphate (nMP) is continuously circulated for ammonia precipitation treatment; and then nM The effluent from the P precipitation enters the biological denitrification process for treatment; (4) the AAO biological denitrification process, the effluent from step (3) is introduced into the anaerobic (A)-anoxic (A)-aerobic (O) biological denitrification process; (5) the remaining small amount of nitrogen is denitrified by a denitrification biological filter and a membrane filter.

[0004] However, the existing technology has the following problems: the existing technology relies on the combination of multiple independent processing units, and the overall stability of the system is greatly affected by the operating status of each unit, resulting in the activity and metabolic stability of microorganisms, thereby leading to the problem of low stability of deep denitrification. Summary of the Invention

[0005] To this end, the present invention provides a suspended filler-driven sulfur autotrophic self-circulating deep denitrification process to overcome the problem that the prior art relies on the combination of multiple independent processing units, and the overall stability of the system is greatly affected by the operating status of each unit, resulting in the activity and metabolic stability of microorganisms, thereby leading to low stability of deep denitrification.

[0006] To achieve the above object, the present invention provides a suspended filler-driven sulfur autotrophic self-circulating deep denitrification process, comprising:

[0007] Add sulfide-iron composite carrier into the anoxic tank, and add modified polyurethane suspended filler into the aerobic tank;

[0008] Sulfur autotrophic denitrifying bacteria and heterotrophic denitrifying bacteria are enriched on a sulfur-iron composite carrier in an anoxic tank;

[0009] injecting the sewage filtered by the mechanical screen into the regulating tank and passing through the anoxic tank;

[0010] Testing the biofilm on the ferrous-sulfur composite carrier to determine the eligibility of the biofilm;

[0011] Enriching Anammox bacteria and short-range nitrifying bacteria on the modified polyurethane suspended filler located in the aerobic tank;

[0012] Detecting the ATP concentration inside the biofilm on the modified polyurethane suspension filler to determine the eligibility of the microbial metabolic activity, and adjusting the dissolved oxygen concentration based on the difference between the ATP concentration threshold and the ATP concentration;

[0013] The denitrification efficiency is determined to be qualified based on the total nitrogen concentration of the sewage after being treated in the regulating tank, the anoxic tank and the aerobic tank, and the preset thickness fluctuation value is adjusted according to the relative difference between the total nitrogen concentration and the preset total nitrogen concentration.

[0014] Furthermore, the sulfur autotrophic denitrifying bacteria adhere to the surface of the sulfur-iron composite carrier to form a biofilm, and the heterotrophic denitrifying bacteria enter the interior of the sulfur-iron composite carrier to form a spatial layered structure with the outer layer being sulfur autotrophic denitrifying bacteria and the inner layer being heterotrophic denitrifying bacteria.

[0015] Furthermore, under the condition that the biofilm thickness is determined to be measured, based on the comparison result that the thickness fluctuation value of the biofilm thickness is greater than a preset thickness fluctuation value, it is determined that the biofilm is unqualified.

[0016] Furthermore, based on a comparison result that the ratio of the preset thickness fluctuation value to the thickness fluctuation value is less than or equal to the preset ratio, it is determined to increase the air circulation rate in the heating coil by a preset rate adjustment coefficient.

[0017] Furthermore, under the condition that the ATP concentration inside the biofilm is determined to be measured, based on the comparison result that the ATP concentration inside the biofilm is less than or equal to the ATP concentration threshold, it is determined that the metabolic activity of the microorganism is unqualified.

[0018] Furthermore, based on a comparison result that the difference between the ATP concentration threshold and the ATP concentration is less than or equal to a preset difference, it is determined that the dissolved oxygen concentration is increased by a first preset concentration adjustment coefficient.

[0019] Furthermore, based on a comparison result that a difference between the ATP concentration threshold and the ATP concentration is greater than a preset difference, it is determined that the dissolved oxygen concentration is increased by a second preset concentration adjustment coefficient.

[0020] Furthermore, based on the comparison result that the total nitrogen concentration of the treated sewage is greater than the preset total nitrogen concentration, it is determined that the denitrification efficiency is unqualified.

[0021] Further, based on a comparison result that the relative difference between the total nitrogen concentration and the preset total nitrogen concentration is less than or equal to the preset relative difference, it is determined that the preset thickness fluctuation value is reduced by a first preset fluctuation adjustment coefficient.

[0022] Further, based on a comparison result that a relative difference between the total nitrogen concentration and the preset total nitrogen concentration is greater than a preset relative difference, it is determined that the preset thickness fluctuation value is reduced by a second preset fluctuation adjustment coefficient.

[0023] Compared with the prior art, the beneficial effect of the present invention lies in that, by introducing sulfur-iron composite carriers and suspended fillers, the present invention provides an ideal attachment and growth environment for sulfur autotrophic denitrifying bacteria, heterotrophic denitrifying bacteria, Anammox bacteria and short-range nitrifying bacteria. The spatial layered structure of the sulfur-iron composite carrier promotes the layered colonization of microorganisms, improves the stability and biological activity of the biofilm, thereby improving the efficiency of sewage treatment. The high specific surface area and porosity of the suspended filler increase the contact area between microorganisms and sewage, promote the degradation of pollutants, and thus improve the stability of deep denitrification.

[0024] Furthermore, the present invention pre-treats raw water through mechanical screens, intercepts large particles and impurities, prevents clogging and wear of treatment equipment, reduces load, improves overall treatment efficiency, and provides stable and homogeneous water inlet conditions for biological treatment.

[0025] Furthermore, the present invention provides an ideal attachment matrix for sulfur autotrophic denitrifying bacteria and heterotrophic denitrifying bacteria by introducing a sulfur-iron composite carrier into the regulating pond, thereby enhancing the attachment ability of microorganisms and promoting synergy between microorganisms to form a biofilm with a spatial layered structure, thereby improving the efficiency and stability of biological treatment and thus improving the stability of deep denitrification.

[0026] Furthermore, the present invention detects the thickness of the biofilm and regulates the temperature of the anoxic tank to optimize the activity of microorganisms. When the biofilm thickness is insufficient, the heating coil parameters are adjusted to optimize the anoxic tank environment, promote the growth and reproduction of microorganisms, increase the metabolic rate of microorganisms, enhance the stability and impact resistance of the biofilm, and ensure the continuity and efficiency of biological treatment.

[0027] Furthermore, the present invention provides a good growth environment for Anammox bacteria and short-range nitrifying bacteria by using suspended fillers made of modified polyurethane materials in the aerobic tank. The high specific surface area and porosity of the suspended fillers increase the contact area between the microorganisms and the sewage, promote the colonization and reproduction of the microorganisms, and form a layered biofilm structure of outer layer nitrifying bacteria and inner layer Anammox bacteria, thereby improving the removal efficiency of nitrogen in sewage.

[0028] Furthermore, the present invention accurately reflects the metabolic activity of microorganisms by monitoring the ATP concentration of the biofilm on the suspended filler. When the ATP concentration is insufficient, the dissolved oxygen concentration in the aerobic tank is adjusted to maintain the normal metabolic activity of the microorganisms, thereby improving the efficiency and stability of the biological treatment.

[0029] Furthermore, the present invention partially returns the sludge after solid-liquid separation in the secondary sedimentation tank to the anoxic tank, and extracts the sulfur-iron composite carrier from the remaining sludge for reuse, thereby reducing waste generation and achieving sulfur autotrophic self-circulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of a suspended filler-driven sulfur autotrophic self-circulating deep denitrification process according to an embodiment of the present invention;

[0031] Figure 2 A flow chart for determining biofilm thickness eligibility according to an embodiment of the present invention;

[0032] Figure 3 A flow chart showing whether the metabolic activity of a microorganism is qualified according to an embodiment of the present invention;

[0033] Figure 4 This is a flow chart for determining and adjusting the dissolved oxygen concentration in an aerobic tank according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0035] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0036] It should be pointed out that the data in this embodiment are obtained by comprehensive analysis and evaluation of the historical test data and the corresponding historical test results of the three months before this test. It can be understood by those skilled in the art that the present invention can determine the above parameters for a single item by selecting the value with the highest proportion as the preset standard parameter based on the data distribution, using weighted summation to use the obtained value as the preset standard parameter, substituting each historical data into a specific formula and using the value obtained by the formula as the preset standard parameter or other selection methods, as long as the present invention can clearly define the different specific situations in the single determination process through the obtained values.

[0037] See also Figure 1 As shown, it is a flow chart of the suspended filler-driven sulfur autotrophic self-circulating deep denitrification process according to an embodiment of the present invention.

[0038] The embodiment of the present invention provides a suspended filler-driven sulfur autotrophic self-circulating deep denitrification process, comprising:

[0039] Step S1: adding a sulfide-iron composite carrier into the anoxic tank and adding a modified polyurethane suspended filler into the aerobic tank;

[0040] Step S2, enriching sulfur autotrophic denitrifying bacteria and heterotrophic denitrifying bacteria on a sulfur-iron composite carrier located in an anoxic tank;

[0041] Step S3, injecting the sewage filtered by the mechanical screen into the regulating tank and flowing through the regulating tank to the anoxic tank;

[0042] Step S4, testing the biofilm on the ferrous sulfide composite carrier to determine the eligibility of the biofilm;

[0043] Step S5, enriching Anammox bacteria and short-range nitrifying bacteria on the modified polyurethane suspended filler located in the aerobic tank;

[0044] Step S6: detecting the ATP concentration inside the biofilm on the modified polyurethane suspension filler to determine the eligibility of the microbial metabolic activity, and adjusting the dissolved oxygen concentration according to the difference between the ATP concentration threshold and the ATP concentration;

[0045] Step S7, determining whether the denitrification efficiency is qualified based on the total nitrogen concentration of the sewage after being treated in the regulating tank, the anoxic tank and the aerobic tank, and adjusting the preset thickness fluctuation value according to the relative difference between the total nitrogen concentration and the preset total nitrogen concentration.

[0046] Specifically, the present invention provides an ideal attachment and growth environment for sulfur-autotrophic denitrifying bacteria, heterotrophic denitrifying bacteria, Anammox bacteria and short-range nitrifying bacteria by introducing a sulfur-iron composite carrier and a modified polyurethane suspended filler. The spatial layered structure of the sulfur-iron composite carrier promotes the layered colonization of microorganisms, improves the stability and biological activity of the biofilm, and thus improves the efficiency of sewage treatment. The high specific surface area and porosity of the suspended filler increase the contact area between microorganisms and sewage, promotes the degradation of pollutants, and thus improves the stability of deep denitrification.

[0047] Specifically, in the embodiment of the present invention, raw water is intercepted by a mechanical screen, the intercepted sewage is passed into a regulating tank, and a pH sensor is used to monitor the pH value of the regulating tank in real time, and the pH value range is 6.5-7.5.

[0048] In the embodiment of the present invention, the raw water refers to untreated sewage.

[0049] In the embodiment of the present invention, the gap of the mechanical screen is less than or equal to 5 mm, and the gap is obtained by taking the average value of the radius of the smallest debris in several historical raw water.

[0050] Specifically, the present invention pre-treats raw water through a mechanical screen, intercepts large particles and impurities, prevents clogging and wear of treatment equipment, reduces load, improves overall treatment efficiency, and provides stable and homogeneous water inlet conditions for biological treatment.

[0051] In an embodiment of the present invention, the sulfide-iron composite carrier is FeS2@C, and the particle size range is 2mm-5mm, preferably 3mm. The core of the sulfide-iron composite carrier is FeS2, @ is coated, and C is a carbon shell.

[0052] In an embodiment of the present invention, the modified polyurethane suspension filler has a ciliary or three-dimensional porous structure, carboxyl groups or amino groups are grafted onto the surface, and the internal cavity provides an anoxic microenvironment for microorganisms.

[0053] Specifically, sulfur autotrophic denitrifying bacteria (Thiobacillus) and heterotrophic denitrifying bacteria (DenitratisonM) are oxygenated onto a sulfur-iron composite carrier in an anoxic tank, and sewage treated in a regulating tank is passed into the anoxic tank, which is also equipped with a stirring device and a heating coil.

[0054] Specifically, the sulfur autotrophic denitrifying bacteria attach to the surface of the sulfur-iron composite carrier to form a biofilm, and the heterotrophic denitrifying bacteria enter the interior of the sulfur-iron composite carrier through the pores of the sulfur-iron composite carrier, forming a spatial layered structure with the sulfur autotrophic denitrifying bacteria as the outer layer and the heterotrophic denitrifying bacteria as the inner layer.

[0055] In an embodiment of the present invention, the stirring speed of the stirring device is set to 20rpm-40rpm, preferably 30rpm, the heating temperature of the heating coil is set to 30°C, and the air circulation rate in the tube is set to 0.5-1.0m / s, preferably 0.8m / s.

[0056] Specifically, the present invention provides an ideal attachment matrix for sulfur autotrophic denitrifying bacteria and heterotrophic denitrifying bacteria by introducing a sulfur-iron composite carrier into the regulating pond, thereby enhancing the attachment ability of microorganisms and promoting synergy between microorganisms, forming a biofilm with a spatial layered structure, improving the efficiency and stability of biological treatment, and thus improving the stability of deep denitrification.

[0057] During the implementation process, the temperature of the anoxic pool was measured, and sulfur-iron composite carrier samples with sulfur autotrophic denitrifying bacteria and heterotrophic denitrifying bacteria were selected from several different temperature zones and fixed on a microscope observation platform. The biofilm surface was focused to measure the observed thickness at several locations on the biofilm surface, and the average values ​​of several groups of observed thicknesses were obtained. The fluctuation of the average value was determined, and the overall qualification of the biofilm was determined based on the fluctuation.

[0058] In an embodiment of the present invention, the plurality of groups of observed thicknesses are preferably 10 groups, and the preferred value is obtained based on statistical calculations. 10 groups of observed thicknesses can provide sufficient data points for calculating the average value and fluctuation range. Too small a sample size may lead to large data deviations, while too large a sample size will increase the complexity and cost of the experiment.

[0059] See also Figure 2 As shown, it is a flow chart of determining the eligibility of biofilm thickness according to an embodiment of the present invention.

[0060] Specifically, in the embodiment of the present invention, under the condition of measuring the thickness of the biofilm, according to the thickness fluctuation value and the preset thickness fluctuation value 50 The comparison results determine the eligibility of the biofilm;

[0061] When the thickness fluctuation value is less than or equal to the preset thickness fluctuation value, the biofilm is determined to be qualified;

[0062] When the thickness fluctuation value is greater than the preset thickness fluctuation value, it is determined that the biofilm is unqualified.

[0063] In the embodiment of the present invention, the preset thickness fluctuation value is 50 The preset thickness fluctuation value is obtained by taking the average of several historical thickness fluctuation values ​​of qualified biofilm thicknesses, but the above value is not limited thereto, and those skilled in the art can also adjust the value according to actual needs.

[0064] Specifically, in the embodiment of the present invention, under the condition that the biofilm is determined to be unqualified, the heating coil parameters are adjusted according to the comparison result of the ratio of the preset thickness fluctuation value to the thickness fluctuation value and the preset ratio of 0.4;

[0065] When the ratio is less than or equal to the preset ratio, it is determined that the air circulation rate in the heating coil is increased to a corresponding value by a preset rate adjustment coefficient of 1.03;

[0066] When the ratio is greater than the preset ratio, it is determined to increase the heating temperature of the heating coil to a corresponding value using a preset temperature adjustment coefficient of 1.07;

[0067] The ratio is the ratio of the preset thickness fluctuation value to the thickness fluctuation value.

[0068] In the embodiment of the present invention, the preset ratio is 0.4, but the above value is not limited thereto, and those skilled in the art may also adjust the value according to actual needs.

[0069] In the embodiment of the present invention, the increased air circulation rate is the product of the air circulation rate and the preset rate adjustment coefficient of 1.03; the increased heating temperature is the product of the heating temperature and the preset temperature adjustment coefficient of 1.07.

[0070] Specifically, the present invention detects the thickness of the biofilm and regulates the temperature of the anoxic tank to optimize the activity of microorganisms. When the biofilm thickness is insufficient, the heating coil parameters are adjusted to optimize the anoxic tank environment, promote the growth and reproduction of microorganisms, increase the metabolic rate of microorganisms, enhance the stability and impact resistance of the biofilm, and ensure the continuity and efficiency of biological treatment.

[0071] Specifically, in an embodiment of the present invention, a suspended filler is prepared using a modified polyurethane material in an aerobic tank. The specific surface area of ​​the suspended filler is 20,000 m² / m³-25,000 m² / m³, preferably 22,000 m² / m³, and the porosity is greater than or equal to 95%. Anammox bacteria (Candidatus Brocadia) and short-range nitrifying bacteria (AOB) are enriched on the suspended filler. A nitrifying bacteria carrier (activated carbon) is pre-coated on the surface of the suspended filler to promote the preferential colonization of short-range nitrifying bacteria. The Anammox bacteria and the short-range nitrifying bacteria form a layered biofilm structure of outer layer nitrifying bacteria-inner layer Anammox bacteria on the suspended filler. After the above-mentioned cultivation process is successful, the sewage treated in the anoxic tank is passed into the aerobic tank.

[0072] Specifically, during the embodiment, nitrite at a concentration of 5 mg / L-10 mg / L is supplemented in the aerobic pool, and ammonia nitrogen at a concentration of 2 mg / L-5 mg / L is added. The ammonia nitrogen is nitrogen in the form of free ammonia (NH3) and ammonium ions (NH4+).

[0073] Specifically, the present invention provides a good growth environment for Anammox bacteria and short-range nitrifying bacteria by using suspended fillers made of modified polyurethane materials in an aerobic tank. The high specific surface area and porosity of the suspended fillers increase the contact area between microorganisms and sewage, promote the colonization and reproduction of microorganisms, and form a layered biofilm structure of outer layer nitrifying bacteria and inner layer Anammox bacteria, thereby improving the removal efficiency of nitrogen in sewage.

[0074] Specifically, in an embodiment of the present invention, under the condition that a suspended filler is used to treat sewage in an aerobic pool, water samples and biofilm samples are collected from the aerobic pool at a frequency of one week, ATP is extracted from the biofilm samples using an ATP extraction kit, and the dissolved oxygen content in the aerobic pool is measured using an electrochemical probe method.

[0075] Specifically, in the implementation process of the embodiment, ATP is extracted using the Fast DNA SPIN for Soil kit, the extracted ATP sample is quantitatively detected by fluorescence, the ATP sample is mixed with a luciferase reagent, the fluorescence intensity is measured using a microplate reader, and the actual concentration value is calculated according to the standard curve. The fluorescence intensity is linearly positively correlated with the ATP concentration. It can be understood that the fluorescence intensity is proportional to the ATP concentration; the process of measuring the dissolved oxygen content by the electrochemical probe method is to immerse the electrode in the water sample, and the oxygen molecules on the electrode surface undergo a reduction reaction, generating a diffusion current proportional to the oxygen concentration, and displaying the dissolved oxygen concentration.

[0076] See also Figure 3 As shown, it is a flow chart of determining whether the metabolic activity of microorganisms is qualified according to an embodiment of the present invention.

[0077] Specifically, in the embodiment of the present invention, under the conditions for extracting the ATP, whether the microbial metabolic activity is qualified is determined based on the comparison result of the ATP concentration inside the biofilm and the ATP concentration threshold;

[0078] When the ATP concentration is less than or equal to the ATP concentration threshold, it is determined that the microbial metabolic activity is unqualified;

[0079] When the ATP concentration is greater than the ATP concentration threshold, it is determined that the metabolic activity of the microorganism is qualified.

[0080] In the embodiment of the present invention, the ATP concentration threshold is 150 nM. The ATP concentration threshold is obtained by taking the average of the ATP concentrations of several historical microbial metabolic activities that meet the requirements. However, the above value is not limited thereto, and those skilled in the art can also adjust the value according to actual needs.

[0081] See also Figure 4 As shown, it is a flow chart of determining and adjusting the dissolved oxygen concentration in the aerobic tank according to an embodiment of the present invention.

[0082] Specifically, in an embodiment of the present invention, under the condition that the metabolic activity of the microorganism is determined to be unqualified, the dissolved oxygen concentration in the aerobic tank is adjusted according to the comparison result of the difference between the ATP concentration threshold and the ATP concentration and the preset difference 15;

[0083] When the difference is less than or equal to the preset difference, it is determined to increase the dissolved oxygen concentration to a corresponding value using a first preset concentration adjustment coefficient of 1.05;

[0084] When the difference is greater than the preset difference, it is determined to increase the dissolved oxygen concentration to a corresponding value using a second preset concentration adjustment coefficient of 1.15;

[0085] The difference is the difference between the ATP concentration threshold and the ATP concentration.

[0086] In the embodiment of the present invention, the preset difference value is 15, but the above value is not limited thereto, and those skilled in the art can also adjust the value according to actual needs.

[0087] In the embodiment of the present invention, the increased dissolved oxygen concentration is the product of the dissolved oxygen concentration and the i-th preset concentration adjustment coefficient, where i is 1 or 2, T1 is the first preset concentration adjustment coefficient 1.05, and T2 is the second preset concentration adjustment coefficient 1.15.

[0088] It can be understood that the dissolved oxygen concentration in the aerobic tank is increased by the air volume of the aeration device, and the aeration device is a forced air aeration device.

[0089] It is understandable that by increasing the dissolved oxygen concentration, the oxidative metabolic rate of microorganisms is directly enhanced, avoiding the decline in biofilm activity caused by insufficient dissolved oxygen. After the dissolved oxygen concentration is increased, the microorganisms' ability to degrade pollutants is enhanced, the stability of the biofilm thickness and density is improved, and the fluctuation of denitrification efficiency is reduced.

[0090] Specifically, the present invention accurately reflects the metabolic activity of microorganisms by monitoring the ATP concentration of the biofilm on the suspended filler. When the ATP concentration is insufficient, the dissolved oxygen concentration in the aerobic tank is adjusted to maintain the normal metabolic activity of the microorganisms, thereby improving the efficiency and stability of the biological treatment.

[0091] Specifically, the embodiment of the present invention determines whether the denitrification efficiency is qualified by comparing the total nitrogen concentration of the sewage after being treated in the regulating tank, the anoxic tank and the aerobic tank with the preset total nitrogen concentration;

[0092] When the total nitrogen concentration is less than or equal to the preset total nitrogen concentration, it is determined that the denitrification efficiency is qualified;

[0093] When the total nitrogen concentration is greater than the preset total nitrogen concentration, it is determined that the denitrification efficiency is unqualified.

[0094] In the embodiment of the present invention, the preset total nitrogen concentration is 10 mg / L. The preset total nitrogen concentration is obtained when the total nitrogen concentration with qualified denitrification efficiency in several historical times takes the maximum value. However, the above value is not limited to this. Those skilled in the art can also adjust the value according to actual needs.

[0095] During the implementation process, the total nitrogen concentration is detected by extracting several groups of treated sewage samples from several sewage areas through a total nitrogen analyzer, and the average value of the detected total nitrogen concentration is obtained to determine the total nitrogen concentration.

[0096] Specifically, in an embodiment of the present invention, under the condition that the denitrification efficiency is determined to be unqualified, the preset thickness fluctuation value is determined to be adjusted according to the comparison result of the relative difference between the total nitrogen concentration and the preset total nitrogen concentration and the preset relative difference;

[0097] When the relative difference is less than or equal to the preset relative difference, it is determined that the preset thickness fluctuation value is reduced to a corresponding value using a first preset fluctuation adjustment coefficient of 0.92;

[0098] When the relative difference is greater than the preset relative difference, it is determined that the preset thickness fluctuation value is reduced to a corresponding value using a second preset fluctuation adjustment coefficient of 0.86;

[0099] The relative difference is the relative difference between the total nitrogen concentration and the preset total nitrogen concentration.

[0100] In the embodiment of the present invention, the preset relative difference value is 0.2, but the above value is not limited thereto, and those skilled in the art may also adjust the value according to actual needs.

[0101] In an embodiment of the present invention, the reduced preset thickness fluctuation value is the product of the preset thickness fluctuation value and the jth preset fluctuation adjustment coefficient, where j is 1 or 2, L1 is the first preset fluctuation adjustment coefficient 0.92, and L2 is the second preset fluctuation adjustment coefficient 0.86.

[0102] It is understood that by reducing the preset thickness fluctuation value and optimizing the thickness uniformity of the biofilm, stricter thickness fluctuation limits can reduce the risk of the biofilm being too thick or too thin in some areas and enhance the impact resistance of the overall biofilm structure.

[0103] Specifically, the sewage treated in the aerobic tank is passed into an airlift fluidized bed, and intermittent aeration is adopted to achieve simultaneous nitrification and denitrification (SND), while a biochar-based growth promoter is pulsed to treat the sewage.

[0104] In the embodiment of the present invention, the intermittent aeration time period is set to 2h-4h, preferably 3h, the air velocity is set to 12mm / s-40 mm / s, preferably 30mm / s, and the dosage of the biochar-based growth promoter is 0.5g / m³.

[0105] Specifically, in the embodiment of the present invention, the effluent after the air lift fluidized bed treatment is separated into solid and liquid in the secondary sedimentation tank, the sludge is returned to the anoxic tank, and the sulfide-iron composite carrier is extracted from the remaining sludge for reuse.

[0106] Specifically, the present invention partially returns the sludge after solid-liquid separation in the secondary sedimentation tank to the anoxic tank, and extracts the sulfur-iron composite carrier from the remaining sludge for reuse, thereby reducing waste generation and achieving sulfur self-feeding and self-circulation.

[0107] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

[0108] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A suspended filler driven sulfur autotrophic self-circulating deep denitrification process, characterized in that: include: Add sulfide-iron composite carrier into the anoxic tank, and add modified polyurethane suspended filler into the aerobic tank; Sulfur autotrophic denitrifying bacteria and heterotrophic denitrifying bacteria are enriched on a sulfur-iron composite carrier in an anoxic tank; The sulfur autotrophic denitrifying bacteria adhere to the surface of the sulfur-iron composite carrier to form a biofilm, and the heterotrophic denitrifying bacteria enter the interior of the sulfur-iron composite carrier to form a spatial layered structure with the sulfur autotrophic denitrifying bacteria as the outer layer and the heterotrophic denitrifying bacteria as the inner layer; injecting the sewage filtered by the mechanical screen into the regulating tank and passing through the anoxic tank; Testing the biofilm on the ferrous-sulfur composite carrier to determine the eligibility of the biofilm; Enriching Anammox bacteria and short-range nitrifying bacteria on the modified polyurethane suspended filler located in the aerobic tank; Detecting the ATP concentration inside the biofilm on the modified polyurethane suspension filler to determine the eligibility of the microbial metabolic activity, and adjusting the dissolved oxygen concentration based on the difference between the ATP concentration threshold and the ATP concentration; Determining whether the denitrification efficiency is qualified based on the total nitrogen concentration of the sewage after being treated in the regulating tank, the anoxic tank, and the aerobic tank, and adjusting the preset thickness fluctuation value according to the relative difference between the total nitrogen concentration and the preset total nitrogen concentration; The preset thickness fluctuation value is obtained by taking the average of several historical thickness fluctuation values ​​of qualified biofilm thicknesses.

2. The suspended filler-driven sulfur autotrophic self-circulating deep denitrification process according to claim 1, characterized in that: Under the condition that the biofilm thickness is determined to be measured, based on the comparison result that the thickness fluctuation value of the biofilm thickness is greater than the preset thickness fluctuation value, it is determined that the biofilm is unqualified.

3. The suspended filler-driven sulfur autotrophic self-circulating deep denitrification process according to claim 2, characterized in that: Based on a comparison result that the ratio of the preset thickness fluctuation value to the thickness fluctuation value is less than or equal to the preset ratio, it is determined to increase the air circulation rate in the heating coil by the preset rate adjustment coefficient.

4. The suspended filler-driven sulfur autotrophic self-circulating deep denitrification process according to claim 3, characterized in that: Under the condition that the ATP concentration inside the biofilm is determined, based on the comparison result that the ATP concentration inside the biofilm is less than or equal to the ATP concentration threshold, it is determined that the metabolic activity of the microorganism is unqualified.

5. The suspended filler-driven sulfur autotrophic self-circulating deep denitrification process according to claim 4, characterized in that: Based on a comparison result that the difference between the ATP concentration threshold and the ATP concentration is less than or equal to a preset difference, it is determined to increase the dissolved oxygen concentration by a first preset concentration adjustment coefficient.

6. The suspended filler-driven sulfur autotrophic self-circulating deep denitrification process according to claim 5, characterized in that: Based on a comparison result that a difference between the ATP concentration threshold and the ATP concentration is greater than a preset difference, it is determined to increase the dissolved oxygen concentration by a second preset concentration adjustment coefficient.

7. The suspended filler-driven sulfur autotrophic self-circulating deep denitrification process according to claim 6, characterized in that: Based on the comparison result that the total nitrogen concentration of the treated sewage is greater than the preset total nitrogen concentration, it is determined that the denitrification efficiency is unqualified.

8. The suspended filler-driven sulfur autotrophic self-circulating deep denitrification process according to claim 7, characterized in that: Based on a comparison result that a relative difference between the total nitrogen concentration and the preset total nitrogen concentration is less than or equal to the preset relative difference, it is determined that the preset thickness fluctuation value is reduced by a first preset fluctuation adjustment coefficient.

9. The suspended filler-driven sulfur autotrophic self-circulating deep denitrification process according to claim 8, characterized in that: Based on a comparison result that a relative difference between the total nitrogen concentration and the preset total nitrogen concentration is greater than the preset relative difference, it is determined that the preset thickness fluctuation value is reduced by a second preset fluctuation adjustment coefficient.

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