Sulfur autotrophic denitrification biological filler and preparation method thereof, sulfur autotrophic denitrification fluidized bed, sulfur autotrophic denitrification filter tank device and application

Abstract

The invention relates to the technical field of sewage treatment, in particular to a sulfur autotrophic denitrification biological filler and a preparation method thereof, a sulfur autotrophic denitrification fluidized bed, a sulfur autotrophic denitrification filter tank device and application. The sulfur autotrophic denitrification biological filler comprises a macromolecular base material, a sulfur autotrophic denitrification nutrition auxiliary material, a conductive functional auxiliary material and an electrophilic functional auxiliary material in a mass ratio of (90-100): (1-5): (0.5-3): (0.5-3); the macromolecular base material comprises at least one of polyethylene and polypropylene; the sulfur autotrophic denitrification nutrition auxiliary material comprises sulfur; the conductive functional auxiliary material comprises sludge-based biochar; the electrophilic functional auxiliary material comprises cationic starch. The sulfur autotrophic denitrification biological filler has the advantages of being high in mass transfer efficiency, capable of improving the electron transfer efficiency between microbial species, high in biocompatibility and the like.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a sulfur autotrophic denitrification biological filler and a preparation method thereof, a sulfur autotrophic denitrification fluidized bed, a sulfur autotrophic denitrification filter device and applications. Background Art

[0002] Nitrate is a kind of nitrogen oxide that is ubiquitous in nature and exists at low to medium levels in nature. However, in the bodies of animals and plants, nitrate nitrogen is a ubiquitous soluble nitrogen. In recent years, a large amount of ammonia has been artificially synthesized in industrial production, and a large amount of nitrogen-containing organic matter has been discharged into water bodies, polluting the water environment. When the nitrate concentration in the water body exceeds a certain limit, it will lead to eutrophication of the water body, excessive reproduction of algae, seriously affecting the photosynthesis of aquatic plants, and causing damage to the aquatic ecosystem and the survival of aquatic organisms. When nitrate enters the human body, it will be converted into compounds such as nitrite and nitrosamide, which pose potential risks to human health. Therefore, effective measures need to be taken to reduce the discharge of nitrates and protect human health and the environment.

[0003] Physical separation, chemical reduction and other physicochemical methods are hot areas of nitrate removal process research, and they can achieve stable and efficient removal of nitrate. However, the above processes all have problems such as high operating costs, complex processes, and risky reagents. Therefore, large-scale sewage treatment plants still mainly use the denitrification process section in traditional biochemical processes to achieve nitrate removal. However, with the improvement of sewage discharge standards, the C / N ratio of urban wastewater in my country, especially in the effluent of secondary processes, has a trend of continuous decline. Therefore, there is usually a lack of carbon source in the denitrification step, and additional carbon sources are required as electron donors to ensure the smooth progress of the denitrification process. This will not only greatly increase the cost of wastewater treatment, but may also lead to higher sludge production and carbon emissions. At the same time, some types of organic carbon sources can combine with chloride ions to form toxic organic compounds, such as trihalomethanes (THMs) and haloacetic acids (HAAs), threatening the ecological safety of the downstream. Based on the above background, the use of autotrophic bacteria with inorganic elements as electron donors to carry out denitrification reactions has gradually become a method for reducing nitrate nitrogen (NO3 - -N) emissions is an attractive option.

[0004] Sulfur autotrophic denitrification (SAD) is a process that can utilize elemental sulfur (S 0 ), sulfide (S 2- ), thiosulfate (S2O3 2- ), thiocyanate (SCN - ) and other cheap reducing sulfur elements as electron donors to convert NO3 --N is converted into N2 by biological process. It can be used not only as a separate process, but also as a supplementary process for traditional denitrification to reduce the overall operating cost of the process. This process is highly efficient, environmentally friendly and has low operating costs. It is very suitable for treating NO3 in wastewater lacking organic carbon sources. - -N. Studies have found that some sulfur-oxidizing bacteria can convert S 0 obtain electrons and convert NO3 - -N is reduced to N2. Due to the chemical synthesis of S 0 It is the most commonly used electron donor in sulfur autotrophic denitrification process because of its low price and easy shaping. 0 Due to its powdery state, high density and strong hydrophobicity, its mass transfer efficiency with activated sludge is always low, which seriously hinders the application of sulfur autotrophic denitrification process.

[0005] Studies have shown that fluidized bed biofillers can provide a place for microorganisms to survive and enhance the mass transfer efficiency between microorganisms and nutrients in the water, thereby effectively increasing the concentration of microorganisms in the biological reaction process. However, no biofillers developed based on sulfur autotrophic denitrification have been found.

[0006] In addition, most of the biological fillers produced domestically are directly processed and molded from polymer materials. The biological fillers produced have poor biological affinity, resulting in slow biofilm formation, easy detachment of biofilm, and low efficiency in removing pollutants.

[0007] In view of this, the present invention is proposed. Summary of the invention

[0008] The first object of the present invention is to provide a sulfur autotrophic denitrification biological filler, which has the advantages of high mass transfer efficiency, improved interspecies electron transfer efficiency of microorganisms and strong biological affinity. 0 There are problems such as low mass transfer efficiency and poor bioaffinity of domestically produced biological fillers, which lead to slow biofilm formation speed and easy biofilm shedding.

[0009] The second object of the present invention is to provide a method for preparing a sulfur autotrophic denitrification biological filler, wherein the sulfur autotrophic denitrification biological filler prepared by the method has strong biological affinity and is highly sensitive to nitrate nitrogen (NO3 - -N) has the advantages of high removal efficiency and can improve the efficiency of electron transfer between microbial species.

[0010] The third object of the present invention is to provide a sulfur autotrophic denitrification fluidized bed, which can enhance the mass transfer efficiency between microorganisms and various nutrients in the water body by filling sulfur autotrophic denitrification biological fillers, thereby achieving NO3 --N for depth processing.

[0011] The fourth object of the present invention is to provide a sulfur autotrophic denitrification filter device, which has the advantages of high mass transfer efficiency, improved interspecies electron transfer efficiency of microorganisms, strong biological affinity, high degree of automation, strong operability, low operating cost, wide application range, and not easy to produce secondary pollution.

[0012] The fifth object of the present invention is to provide the use of sulfur autotrophic denitrification biological filler, sulfur autotrophic denitrification fluidized bed and sulfur autotrophic denitrification filter device in removing nitrate nitrogen.

[0013] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0014] The present invention first provides a sulfur autotrophic denitrification biological filler, which includes a polymer base material, a sulfur autotrophic denitrification nutrient auxiliary material, a conductive functional auxiliary material and an electrophilic functional auxiliary material in a mass ratio of 90-100:1-5:0.5-3:0.5-3; wherein the polymer base material includes at least one of polyethylene and polypropylene; the sulfur autotrophic denitrification nutrient auxiliary material includes sulfur; the conductive functional auxiliary material includes sludge-based biochar; and the electrophilic functional auxiliary material includes cationic starch.

[0015] Furthermore, the mass ratio of the polymer base material, the sulfur autotrophic denitrification nutrient auxiliary material, the conductive functional auxiliary material and the electrophilic functional auxiliary material is 93-97: 2-4: 0.5-2: 0.5-2.

[0016] Furthermore, the mass ratio of the polymer base material, the sulfur autotrophic denitrification nutrient auxiliary material, the conductive functional auxiliary material and the electrophilic functional auxiliary material is 95:3:1:1.

[0017] Furthermore, the ratio of the mass of the polymer base material to the sum of the mass of the sulfur autotrophic denitrification nutrient auxiliary material, the conductive functional auxiliary material and the electrophilic functional auxiliary material is 15-25:1.

[0018] Furthermore, the density of the sulfur autotrophic denitrifying biological filler is 0.9-1.1 g / cm 3 .

[0019] Furthermore, the density of the polyethylene is less than 0.95 g / cm 3 .

[0020] The present invention further provides a method for preparing the sulfur autotrophic denitrifying biological filler, comprising the following steps: uniformly mixing various raw materials and then granulating to obtain granular materials; and extruding the granular materials to obtain the sulfur autotrophic denitrifying biological filler.

[0021] Furthermore, the particle size distribution range of the granular material is 3 to 5 mm.

[0022] Furthermore, the extrusion temperature is ≥135°C.

[0023] Furthermore, the extrusion further includes a cutting step.

[0024] The present invention further provides a sulfur autotrophic denitrification fluidized bed, which comprises the sulfur autotrophic denitrification biological filler.

[0025] The present invention further provides a sulfur autotrophic denitrification filter device, which comprises a regulating tank, a sulfur autotrophic MBBR tank and an MBR tank connected in sequence; wherein the sulfur autotrophic MBBR tank comprises a suspended packing bed, and the suspended packing bed is filled with the sulfur autotrophic denitrification biological filler.

[0026] Furthermore, the regulating tank includes a first stirring device.

[0027] Furthermore, the sulfur autotrophic MBBR tank includes a second stirring device.

[0028] Furthermore, a water inlet pump and a water inlet flow meter are provided on the pipeline between the regulating tank and the sulfur autotrophic MBBR tank.

[0029] Furthermore, the sulfur autotrophic MBBR tank is also connected to a dosing tank; the dosing tank includes a third stirring device; and a dosing pump is provided between the dosing tank and the sulfur autotrophic MBBR tank.

[0030] Furthermore, a self-aeration MBR device is arranged inside the MBR pool; and the self-aeration MBR device is connected to a fan.

[0031] Furthermore, the sulfur autotrophic denitrification filter device also includes an electric control cabinet.

[0032] The present invention also provides the use of the sulfur autotrophic denitrification biological filler, the sulfur autotrophic denitrification fluidized bed or the sulfur autotrophic denitrification filter device in removing nitrate nitrogen.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The sulfur autotrophic denitrification biological filler provided by the present invention has the advantages of high mass transfer efficiency, can improve the efficiency of electron transfer between microbial species, strong biological affinity, low cost, high efficiency, wide applicability and environmental protection, and can achieve NO3 in wastewater. - -N for deep removal.

[0035] (2) The sulfur autotrophic denitrification biological filler prepared by the preparation method of the sulfur autotrophic denitrification biological filler provided by the present invention has strong biological affinity and is resistant to nitrate nitrogen (NO3 --N) removal efficiency is high, the efficiency of electron transfer between microorganisms can be improved, and the cost is low.

[0036] (3) The sulfur autotrophic denitrification fluidized bed provided by the present invention can enhance the mass transfer efficiency between microorganisms and various nutrients in the water body, and achieve NO3 - -N for depth processing.

[0037] (4) The sulfur autotrophic denitrification filter device provided by the present invention uses the sulfur autotrophic denitrification biological filler as a nutrient to drive the operation of the sulfur autotrophic denitrification filter device, which can achieve NO3 - -N pollution is efficiently treated. In addition, the sulfur autotrophic denitrification filter device has the advantages of high automation, strong operability, low operating cost, wide application range and not easy to produce secondary pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 This is a schematic structural diagram of the sulfur autotrophic denitrification filter device provided by the present invention.

[0040] Reference numerals:

[0041] 1-regulating tank; 2-sulfur autotrophic MBBR tank; 3-MBR tank; 4-first stirring device; 5-second stirring device; 6-water inlet pump; 7-water inlet flow meter; 8-dosing tank; 9-third stirring device; 10-dosing pump; 11-self-aeration MBR device; 12-electric control cabinet. DETAILED DESCRIPTION

[0042] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0043] In a first aspect, the present invention provides a sulfur autotrophic denitrification biological filler, comprising a polymer base material, a sulfur autotrophic denitrification nutrient auxiliary material, a conductive functional auxiliary material and an electrophilic functional auxiliary material in a mass ratio of 90-100 (including but not limited to any one of 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100 or a range between two of them): 1-5 (including but not limited to any one of 1, 2, 3, 4, 5 or a range between two of them): 0.5-3 (including but not limited to any one of 0.5, 0.6, 0.8, 1, 1.2, 1.3, 1.5, 1.8, 2, 2.5, 3 or a range between two of them): 0.5-3 (including but not limited to any one of 0.5, 0.6, 0.8, 1, 1.2, 1.3, 1.5, 1.8, 2, 2.5, 3 or a range between two of them).

[0044] Wherein, the polymer base material includes at least one of polyethylene and polypropylene.

[0045] The sulfur autotrophic denitrification nutrient auxiliary material includes sulfur, preferably powdered sulfur.

[0046] The conductive functional auxiliary material includes sludge-based biochar, preferably powdered sludge-based biochar.

[0047] The electrophilic functional auxiliary material includes cationic starch.

[0048] The sulfur autotrophic denitrification biological filler provided by the present invention has the advantages of high mass transfer efficiency, ability to improve interspecies electron transfer efficiency of microorganisms, strong biological affinity, low cost, high efficiency, wide applicability and environmental protection.

[0049] The sulfur autotrophic denitrification biological filler provided by the present invention can quickly and effectively drive the sulfur autotrophic denitrification reaction, and can achieve the reduction of NO3 in the secondary effluent of urban wastewater. - -N for deep removal.

[0050] Sulfur autotrophic denitrification is the main reaction of microorganisms. The present invention uses materials such as polyethylene as polymer base materials to provide a biological filler skeleton, uses sulfur as a sulfur autotrophic denitrification nutritional auxiliary material to provide nutrients required by sulfur autotrophic denitrification organisms, uses sludge-based biochar as a conductive functional auxiliary material to improve the electron transfer efficiency between microbial populations and thus improve the sulfur autotrophic denitrification efficiency, and uses cationic starch as an electrophilic functional auxiliary material to improve the overall biological affinity of the biological filler and thus improve the biofilm generation rate of microorganisms. Therefore, the present invention can improve the startup rate and operation stability of the process.

[0051] The above components, when combined in a specific ratio, can effectively improve the efficiency of electron transfer between microbial species and achieve NO3 --N for depth processing.

[0052] Therefore, the present invention solves the problem in the prior art that 0 There are problems such as low mass transfer efficiency and poor bioaffinity of domestically produced biological fillers, which lead to slow biofilm formation speed and easy biofilm shedding.

[0053] In addition, the sulfur autotrophic denitrification biological filler provided by the present invention can improve the interspecies electron transfer efficiency, and its internal nutrients will be slowly consumed by the sulfur autotrophic biofilm formed on the surface of the filler, which can greatly reduce the waste of medicines compared with the prior art. And it can be replaced in time according to the consumption situation, which can greatly reduce the problems of filler blockage and the like compared with the prior art. Specifically, the prior art is mostly in the form of a fixed filler bed, the filler is relatively heavy, and the consumption degree of each part will be different, and it is difficult to replace it in time according to the actual consumption of each part; while the present invention adopts the form of fluidized bed biological filler (MBBR), during operation, all fillers are always in a fluidized state, so the consumption degree is consistent, and when replacement is required, it can be directly cleaned and added as a whole, without causing waste. In addition, during the cleaning and adding process, the operation difficulty of the lightweight filler in the present invention is also much lower than that of the existing fixed bed form.

[0054] In some specific implementations, the mass ratio of the polymer base material, the sulfur autotrophic denitrification nutrient auxiliary material, the conductive functional auxiliary material and the electrophilic functional auxiliary material is 93-97:2-4:0.5-2:0.5-2.

[0055] In some specific embodiments, the mass ratio of the polymer base material, the sulfur autotrophic denitrification nutrient auxiliary material, the conductive functional auxiliary material and the electrophilic functional auxiliary material is 95:3:1:1. Under this ratio, the density of the obtained sulfur autotrophic denitrification biological filler is about 1g / cm 3 , close to water, so the fluidization state of the filler is better.

[0056] In some specific embodiments, the ratio of the mass of the polymer base material to the sum of the masses of the sulfur autotrophic denitrification nutrient auxiliary material, the conductive functional auxiliary material and the electrophilic functional auxiliary material is 15 to 25:1, including but not limited to any one of 15:1, 16:1, 17:1, 18:1, 18.5:1, 19:1, 19.5:1, 20:1, 21:1, 22:1, 25:1 or the range value between any two of them.

[0057] In some specific embodiments, the density of the sulfur autotrophic denitrifying biological filler is 0.9-1.1 g / cm 3 , including but not limited to 0.9g / cm 3 , 0.95g / cm 3 , 1g / cm3 , 1.05g / cm 3 , 1.1g / cm 3 Any point value in or any range between them.

[0058] In some specific embodiments, the density of the polyethylene is less than 0.95 g / cm 3 , preferably greater than or equal to 0.9 g / cm 3 And less than 0.95g / cm 3 .

[0059] In some specific embodiments, the particle size of the sulfur autotrophic denitrification nutrient auxiliary material is less than 0.5 mm; the particle size of the conductive functional auxiliary material is less than 0.5 mm; and the particle size of the electrophilic functional auxiliary material is less than 0.5 mm. This can improve the uniformity of material distribution.

[0060] In some specific embodiments, the sulfur autotrophic denitrifying biological filler can be used as a biological filler in a fluidized bed, or can be used as a nutrient to fill a suspended filler bed.

[0061] It is understandable that the sulfur autotrophic denitrifying biological filler is a consumable biological filler. During use, a porous structure will gradually appear on the surface of the filler, and the filler needs to be regularly replenished into the system.

[0062] It is understandable that sulfur autotrophic denitrifying biological fillers should be kept away from high-temperature items as much as possible during storage and transportation.

[0063] In a second aspect, the present invention provides a method for preparing the above-mentioned sulfur autotrophic denitrifying biological filler, comprising the following steps: uniformly mixing the raw materials and then granulating to obtain a granular material; heating and extruding the granular material and then cooling to obtain the sulfur autotrophic denitrifying biological filler. Wherein, an appropriate extrusion die can be used for the extrusion operation according to the needs.

[0064] The sulfur autotrophic denitrification biological filler prepared by the preparation method has strong biological affinity and is very suitable for nitrate nitrogen (NO3 - -N) has the advantages of high removal efficiency and can improve the efficiency of electron transfer between microbial species.

[0065] Among them, before extrusion, the raw materials are mixed evenly and then granulated, which is beneficial to further improve the bioaffinity of the obtained sulfur autotrophic denitrification biological filler.

[0066] In addition, the preparation method has the advantages of simple operation, low cost, and suitability for mass production.

[0067] In some specific implementations, the particle size distribution range of the granular material is 3 to 5 mm.

[0068] In some specific embodiments, the extrusion temperature is ≥135°C, including but not limited to any point value of 135°C, 140°C, 145°C, 150°C, 160°C, 180°C, 200°C or a range value between any two thereof; preferably 135-150°C for energy saving.

[0069] In some specific embodiments, the extrusion further includes a cutting step.

[0070] It can be understood that during the extrusion process, the granular material is heated to form a molten state, and has a certain shape after being extruded through a mold. A suitable mold can be selected according to needs. In the present invention, the shape of the sulfur autotrophic denitrification biological filler obtained after extrusion through the mold is a columnar shape with a hollow structure, and the diameter of the sulfur autotrophic denitrification biological filler after cutting can be 5 to 25 mm.

[0071] In some specific implementations, the raw materials are fully mixed using a powder mixer.

[0072] In some specific implementations, a granulator is used to process the uniformly mixed material into granular material.

[0073] In some specific embodiments, the granular material is heated at high temperature by a screw extruder to form a slurry, and the slurry is extruded at high temperature by a screw extruder in the presence of ventilation equipment. The shape of the extruded strip tube is determined by a mold, and after the strip tube is cooled, it can be cut into any size as needed.

[0074] In some specific embodiments, the obtained sulfur autotrophic denitrifying biological filler is fully cleaned and dried after cutting.

[0075] In a third aspect, the present invention provides a sulfur autotrophic denitrification fluidized bed, which includes the above-mentioned sulfur autotrophic denitrification biological filler.

[0076] Sulfur autotrophic denitrification biological filler can be used as a fluidized bed biological filler when used, which can enhance the mass transfer efficiency between microorganisms and various nutrients in the water body, and achieve NO3 - -N for depth processing.

[0077] In a fourth aspect, the present invention provides a suspended packing bed driven sulfur autotrophic denitrification filter device, which mainly realizes the deep removal of nitrates in wastewater through sulfur autotrophic denitrification technology, such as Figure 1The structure diagram of the sulfur autotrophic denitrification filter device is shown, which includes a regulating tank 1, a sulfur autotrophic MBBR tank 2 and an MBR tank 3 which are connected in sequence. Among them, the regulating tank 1 mainly functions to homogenize the wastewater, and the homogenization is to temporarily store the water to avoid sudden changes in water quality affecting the activity of microorganisms. The sulfur autotrophic MBBR tank 2 is mainly used for sulfur autotrophic denitrification reaction. The MBR tank 3 is mainly used to intercept microorganisms (or sulfur autotrophic denitrification sludge) to prevent their loss.

[0078] The sulfur autotrophic MBBR pool 2 comprises a suspended packing bed, in which the above-mentioned sulfur autotrophic denitrifying biological filler is filled.

[0079] The sulfur autotrophic denitrifying biological filler added inside the sulfur autotrophic MBBR pool 2 is used to provide nutrients and provide a place for the attachment of activated sludge.

[0080] The present invention utilizes sulfur autotrophic denitrification biological filler as a nutrient to drive the operation of the sulfur autotrophic denitrification filter device, which can achieve NO3 - -N deep treatment of pollution.

[0081] In addition, the sulfur autotrophic denitrification filter device has the advantages of high mass transfer efficiency, improved electron transfer efficiency between microbial species, strong biological affinity, high degree of automation, strong operability, low operating cost, wide application range, and not easy to produce secondary pollution.

[0082] In some specific embodiments, the filling amount of the sulfur autotrophic denitrifying biological filler in the sulfur autotrophic MBBR pool 2 is 40% to 50% of the effective volume of the sulfur autotrophic MBBR pool 2, including but not limited to any point value of 40%, 42%, 43%, 45%, 48%, 50% or any range value between two of them.

[0083] In some specific implementations, the regulating tank 1 includes a first stirring device 4 for stirring the wastewater in the regulating tank 1 .

[0084] In some specific embodiments, the sulfur autotrophic MBBR pool 2 includes a second stirring device 5, which is used to stir the wastewater in the sulfur autotrophic MBBR pool 2 for homogenization.

[0085] In some specific implementations, a water inlet pump 6 and a water inlet flow meter 7 are provided on the pipeline between the regulating tank 1 and the sulfur autotrophic MBBR tank 2 .

[0086] In some specific implementations, the bottom of the regulating tank 1 is connected to the subsequent unit (sulfur autotrophic MBBR tank 2) through a pipeline, an inlet pump 6, and an inlet flow meter 7. The inlet pump 6 and the inlet flow meter 7 jointly regulate the inlet flow rate entering the subsequent unit.

[0087] In some specific implementations, the sulfur autotrophic MBBR tank 2 is also connected to a dosing tank 8 .

[0088] In some specific implementations, the dosing tank 8 includes a third stirring device 9 .

[0089] In some specific implementations, a dosing pump 10 is provided between the dosing tank 8 and the sulfur autotrophic MBBR tank 2 .

[0090] In some specific embodiments, the reagent in the dosing tank 8 is a mixture of various nutrients that assist the growth of microorganisms, such as a mixed reagent of inorganic alkalinity and nutrients, but not limited to this. The specific dosage and type of dosing can be determined according to the concentration of nitrate in the system influent. The added reagent is mixed with water and stirred evenly by the third stirring device 9, and then pumped into the sulfur autotrophic denitrification biofilter through the dosing pump 10, mixed with the wastewater, and nitrate nitrogen is removed. Among them, under the action of the sulfur autotrophic denitrification related microbial flora, NO3 in the wastewater is removed. - -N is reduced to N2 and released, achieving the degradation of nitrate nitrogen.

[0091] In some specific embodiments, the top outlet of the sulfur autotrophic MBBR pool 2 is connected to the water inlet at the top of the MBR pool 3 through a pipeline. The top of the MBR pool 3 is also provided with an outlet, which is responsible for the water outlet of the entire device.

[0092] In some specific implementations, a self-aerating MBR device 11 is provided inside the MBR pool 3; the self-aerating MBR device 11 is connected to a fan. The fan is used to supply air to the self-aerating MBR device 11. The self-aerating MBR device 11 has good self-cleaning properties and can reduce the frequency of manual cleaning.

[0093] In some specific implementations, the sulfur autotrophic denitrification filter device further includes an electric control cabinet 12. The electric control cabinet 12 is responsible for controlling the working state of each unit in the device.

[0094] In some specific implementations, the sludge outlet at the bottom of the MBR tank 3 is connected to the bottom of the sulfur autotrophic MBBR tank 2 through a pipeline, and the sludge can also be directly discharged out of the system.

[0095] In some specific embodiments, the working principle of the sulfur autotrophic denitrification filter device is as follows: the wastewater enters the regulating tank 1, and the main function of the regulating tank 1 is to homogenize the wastewater. Then, the wastewater is pumped into the system through the water inlet pump 6, and passes through the sulfur autotrophic MBBR tank 2 and the MBR tank 3 in turn to complete the denitrification of NO3 in the wastewater. --N removal. Finally, the treated wastewater flows through the self-aeration MBR device 11 and is discharged from the device. The entire device is controlled by the electric control cabinet 12. The dosage and type of the dosing can be determined according to the NO3 - -N concentration determination.

[0096] The sulfur autotrophic denitrification process is an anaerobic microbial process. In some specific implementations, the dissolved oxygen concentration in the sulfur autotrophic MBBR pool 2 is in the range of DO≤0.5 mg / L.

[0097] In some specific embodiments, the reaction time of the sulfur autotrophic reaction in the sulfur autotrophic MBBR pool 2 is 30 to 240 minutes, including but not limited to any point value of 30 minutes, 40 minutes, 60 minutes, 80 minutes, 90 minutes, 120 minutes, 160 minutes, 180 minutes, 200 minutes, and 240 minutes, or any range value between two of them. It can be specifically determined according to the concentration of nitrate in the influent of the device, and adjusted by the influent flow rate and the effective volume of the pool body.

[0098] In a fifth aspect, the present invention provides the use of the above-mentioned sulfur autotrophic denitrification biological filler, the above-mentioned sulfur autotrophic denitrification fluidized bed, and the above-mentioned sulfur autotrophic denitrification filter device in removing nitrate nitrogen.

[0099] The above-mentioned sulfur autotrophic denitrification biological filler, the above-mentioned sulfur autotrophic denitrification fluidized bed, and the above-mentioned sulfur autotrophic denitrification filter device can achieve NO3 - -N deep processing and efficient removal.

[0100] The embodiments of the present invention will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. If no specific conditions are specified in the examples, the conditions are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0101] Example 1

[0102] The preparation method of the sulfur autotrophic denitrifying biological filler provided in this embodiment comprises the following steps:

[0103] (1) Polyethylene (density 0.91 g / cm 3), sulfur powder (particle size less than 0.5mm), sludge-based biochar powder (particle size less than 0.5mm), and cationic starch powder (particle size less than 0.5mm) are fully mixed (that is, the ratio of the mass of the polymer base material to the sum of the mass of the sulfur autotrophic denitrification nutrient auxiliary material, the conductive functional auxiliary material and the electrophilic functional auxiliary material is 19:1), and then the evenly mixed powder is granulated by a granulator and processed into granular material with a particle size distribution range of 3 to 5mm.

[0104] (2) using a screw extruder to heat the pellets obtained in step (1) at a high temperature (135° C.) to form a slurry, and then using a screw extruder to extrude the slurry at a high temperature in the presence of ventilation equipment, the extrusion temperature being 135° C., the extruded strip tubes being cooled and cut, and then fully cleaned and dried to obtain a sulfur autotrophic denitrification biological filler capable of improving interspecies electron transfer efficiency. The density of the sulfur autotrophic denitrification biological filler is 0.95 g / cm 3 .

[0105] Example 2

[0106] The preparation method of the sulfur autotrophic denitrification biological filler provided in this embodiment is basically the same as that in Example 1, except that in step (1), the mass ratio of polyethylene, sulfur powder, sludge-based biochar powder, and cationic starch powder is replaced with 93:4:2:2 (i.e., the ratio of the mass of the polymer base material to the sum of the mass of the sulfur autotrophic denitrification nutritional auxiliary material, the conductive functional auxiliary material, and the electrophilic functional auxiliary material is 12:1). The density of the sulfur autotrophic denitrification biological filler prepared in this embodiment is 1.05 g / cm 3 .

[0107] Example 3

[0108] The preparation method of the sulfur autotrophic denitrification biological filler provided in this embodiment is basically the same as that in Example 1, except that in step (1), the mass ratio of polyethylene, sulfur powder, sludge-based biochar powder, and cationic starch powder is replaced with 97:2:0.5:0.5 (i.e., the ratio of the mass of the polymer base material to the sum of the mass of the sulfur autotrophic denitrification nutritional auxiliary material, the conductive functional auxiliary material, and the electrophilic functional auxiliary material is 32:1). The density of the sulfur autotrophic denitrification biological filler prepared in this embodiment is 0.92 g / cm 3 .

[0109] Example 4

[0110] The preparation method of the sulfur autotrophic denitrification biological filler provided in this embodiment is basically the same as that in Example 1, except that in step (1), the mass ratio of polyethylene, sulfur powder, sludge-based biochar powder, and cationic starch powder is replaced with 100:3:3:3 (i.e., the ratio of the mass of the polymer base material to the sum of the mass of the sulfur autotrophic denitrification nutritional auxiliary material, the conductive functional auxiliary material, and the electrophilic functional auxiliary material is 11:1). The density of the sulfur autotrophic denitrification biological filler prepared in this embodiment is 0.90 g / cm 3 .

[0111] Example 5

[0112] The preparation method of the sulfur autotrophic denitrifying biological filler provided in this embodiment is basically the same as that in embodiment 1, except that in step (1), the polyethylene in embodiment 1 is replaced by polypropylene, whose density is 0.90 g / cm 3 The density of the sulfur autotrophic denitrification biological filler prepared in this embodiment is 0.91 g / cm 3 .

[0113] Example 6

[0114] The present embodiment provides a suspended filler bed driven sulfur autotrophic denitrification filter device that can improve the interspecies electron transfer efficiency, which includes a regulating tank 1, a sulfur autotrophic MBBR tank 2 and an MBR tank 3 connected in sequence. Among them, the regulating tank 1 is provided with a first stirring device 4. The sulfur autotrophic MBBR tank 2 is filled with the sulfur autotrophic denitrification biological filler prepared in Example 1, and the sulfur autotrophic MBBR tank 2 is provided with a second stirring device 5. The pipeline between the regulating tank 1 and the sulfur autotrophic MBBR tank 2 is provided with a water inlet pump 6 and a water inlet flowmeter 7 in sequence, and the water inlet flowmeter 7 is used to control the water inlet flow to adjust the hydraulic retention time. The sulfur autotrophic MBBR tank 2 is also connected to a dosing tank 8; the dosing tank 8 is provided with a third stirring device 9, which is used to stir the agent. And a dosing pump 10 is provided on the pipeline between the dosing tank 8 and the sulfur autotrophic MBBR tank 2, which is used to add the agent to the sulfur autotrophic MBBR tank 2. A self-aeration MBR device 11 is arranged in the MBR pool 3, and the self-aeration MBR device 11 is connected to the fan through a pipeline. The sulfur autotrophic denitrification filter device also includes an electric control cabinet 12, and the entire device is controlled by the electric control cabinet 12. The effluent of the sulfur autotrophic denitrification filter device enters the MBR pool 3 and is then discharged from the device.

[0115] Comparative Example 1

[0116] The preparation method of the filler provided in this comparative example is basically the same as that in Example 1, except that in step (1), no cationic starch powder is added. The density of the filler prepared in this comparative example is 0.95 g / cm 3 .

[0117] Comparative Example 2

[0118] The preparation method of the filler provided in this comparative example is basically the same as that in Example 1, except that in step (1), no sludge-based biochar powder is added. The density of the filler prepared in this comparative example is 0.95 g / cm 3 .

[0119] Comparative Example 3

[0120] The preparation method of the filler provided in this comparative example is basically the same as that in Example 1, except that in step (1), no sulfur powder is added. The density of the filler prepared in this comparative example is 0.90 g / cm 3 .

[0121] Comparative Example 4

[0122] The preparation method of the filler provided in this comparative example is basically the same as that of Example 1, except that in step (1), the mass ratio of polyethylene, sulfur powder, sludge-based biochar powder, and cationic starch powder is replaced with 90:10:5:5.

[0123] The daily water treatment capacity of a certain urban wastewater treatment plant is 100,000 m 3 / d, and NO3 - -N concentration is about 14-20 mg / L. The sulfur autotrophic denitrification filter device provided in Example 6 is used, which includes the sulfur autotrophic denitrification biological filler prepared in Example 1, which is used as a sulfur autotrophic denitrification agent and assisted by a hanging filler to remove the residual NO3 in the secondary effluent. - -N is processed. After a period of operation, the effluent NO3 - -N is lower than 1 mg / L, and the specific water quality indicators and removal rates are shown in Table 1. Sample 1, Sample 2, and Sample 3 in Table 1 refer to different batches of secondary effluent from urban wastewater.

[0124] Table 1 Comparison of water quality indicators before and after urban wastewater treatment

[0125]

[0126] It can be seen from Table 1 that the sulfur autotrophic denitrification filter device provided in Example 6 and the sulfur autotrophic denitrification biological filler prepared in Example 1 can be used to obtain NO3 - -N is lower than 1mg / L, NO3 - -N removal rate reaches more than 95% NO3 - The average removal rate of -N was 96.7%.

[0127] Furthermore, the sulfur autotrophic denitrification filter device provided in Example 6 was used, and the sulfur autotrophic denitrification biological filler prepared in Example 1 was replaced with the sulfur autotrophic denitrification biological filler prepared in Examples 2 to 5 and the filler prepared in Comparative Examples 1 to 4, respectively, to treat the secondary effluent of the same batch of urban wastewater (Sample 1), and the results are shown in Table 2.

[0128] Table 2 Comparison of water quality indicators before and after urban wastewater treatment

[0129]

[0130] It can be seen from Table 2 that the sulfur autotrophic denitrification biological fillers prepared in various embodiments for treating the secondary effluent of urban wastewater have an effect on NO3 - -N has a high removal rate, while the removal rates of the comparative examples are lower.

[0131] Specifically, the filler of Comparative Example 1 does not contain cationic starch, which results in poor electrophilicity of the biological filler and poor biofilm growth on the filler surface, thereby affecting the TN removal rate.

[0132] The filler of Comparative Example 2 does not contain sludge-based biochar, resulting in poor electron transfer capacity of the biological filler, which in turn affects the TN removal rate.

[0133] The filler of Comparative Example 3 does not contain sulfur, resulting in a lack of nutrient sources for the sulfur autotrophic denitrification process, which in turn leads to an extremely low TN removal rate.

[0134] The contents of sulfur, sludge-based biochar and cationic starch in the filler of Comparative Example 4 are too high, resulting in the inability to process and shape the biological filler.

[0135] In summary, the sulfur autotrophic denitrification biological filler and the sulfur autotrophic denitrification filter device provided by the present invention can achieve the nitrate nitrogen (NO3 - -N) with a removal rate of over 94%.

[0136] Although the present invention has been illustrated and described with specific embodiments, it should be appreciated that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Those skilled in the art should understand that the technical solutions described in the above embodiments may be modified, or some or all of the technical features thereof may be replaced by equivalents without departing from the spirit and scope of the present invention. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. Therefore, this means that all such replacements and modifications within the scope of the present invention are included in the appended claims.

Claims

1. Sulfur autotrophic denitrification biological filler, characterized in that: It includes a polymer base material, a sulfur autotrophic denitrification nutrient auxiliary material, a conductive functional auxiliary material and an electrophilic functional auxiliary material in a mass ratio of 90-100:1-5:0.5-3:0.5-3; Wherein, the polymer base material includes at least one of polyethylene and polypropylene; The sulfur autotrophic denitrification nutrient auxiliary material includes sulfur; The conductive functional auxiliary material includes sludge-based biochar; The electrophilic functional auxiliary material includes cationic starch.

2. The sulfur autotrophic denitrifying biological filler according to claim 1, characterized in that: At least one of the following conditions is met: (1) The mass ratio of the polymer base material, the sulfur autotrophic denitrification nutrient auxiliary material, the conductive functional auxiliary material and the electrophilic functional auxiliary material is 93-97: 2-4: 0.5-2: 0.5-2; (2) The mass ratio of the polymer base material, the sulfur autotrophic denitrification nutrient auxiliary material, the conductive functional auxiliary material and the electrophilic functional auxiliary material is 95:3:1:1; (3) The ratio of the mass of the polymer base material to the sum of the mass of the sulfur autotrophic denitrification nutrient auxiliary material, the conductive functional auxiliary material and the electrophilic functional auxiliary material is 15 to 25:

1.

3. The sulfur autotrophic denitrifying biological filler according to claim 1, characterized in that: The density of the sulfur autotrophic denitrifying biological filler is 0.9-1.1 g / cm 3 .

4. The sulfur autotrophic denitrifying biological filler according to claim 1, characterized in that: The density of the polyethylene is less than 0.95 g / cm 3 .

5. The method for preparing the sulfur autotrophic denitrifying biological filler according to any one of claims 1 to 4, characterized in that: The steps include: The raw materials are mixed evenly and then granulated to obtain granular materials; After the granular material is extruded, the sulfur autotrophic denitrification biological filler is obtained.

6. The method for preparing the sulfur autotrophic denitrifying biological filler according to claim 5, characterized in that: At least one of the following conditions is met: (1) The particle size distribution range of the granular material is 3 to 5 mm; (2) The extrusion temperature is ≥135°C; (3) The extrusion step further includes a cutting step.

7. Sulfur autotrophic denitrification fluidized bed, characterized in that: It comprises the sulfur autotrophic denitrifying biological filler as claimed in any one of claims 1 to 4.

8. Sulfur autotrophic denitrification filter device, characterized in that: It comprises a regulating tank, a sulfur autotrophic MBBR tank and an MBR tank which are connected in sequence; wherein the sulfur autotrophic MBBR tank comprises a suspended packing bed, and the suspended packing bed is filled with the sulfur autotrophic denitrifying biological filler according to any one of claims 1 to 4.

9. The sulfur autotrophic denitrification filter device according to claim 8, characterized in that: At least one of the following conditions is met: (1) The regulating tank includes a first stirring device; (2) The sulfur autotrophic MBBR tank includes a second stirring device; (3) A water inlet pump and a water inlet flow meter are provided on the pipeline between the regulating tank and the sulfur autotrophic MBBR tank; (4) The sulfur autotrophic MBBR tank is also connected to a dosing tank; the dosing tank includes a third stirring device; a dosing pump is provided between the dosing tank and the sulfur autotrophic MBBR tank; (5) A self-aeration MBR device is provided inside the MBR pool; the self-aeration MBR device is connected to a fan; (6) The sulfur autotrophic denitrification filter device also includes an electric control cabinet.

10. Use of the sulfur autotrophic denitrification biological filler according to any one of claims 1 to 4, the sulfur autotrophic denitrification fluidized bed according to claim 7, or the sulfur autotrophic denitrification filter device according to claim 8 in removing nitrate nitrogen.

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