Composite nutritional reducing microorganism filler, preparation method thereof, composite nutritional reducing microorganism fluidized bed and application of composite nutritional reducing microorganism fluidized bed

Abstract

The invention relates to the technical field of sewage treatment, in particular to a composite nutritional reducing microorganism filler and a preparation method thereof, and a composite nutritional reducing microorganism fluidized bed and application thereof. The composite nutritional reducing microorganism filler comprises a biochar carrier as well as a sulfur autotrophic reduction nutrient component and an iron autotrophic reduction nutrient component which are loaded on the biochar carrier, the mass ratio of the biochar carrier to the sulfur autotrophic reduction nutrient component to the iron autotrophic reduction nutrient component is (90-95): (3-7): (1-5); the main component of the sulfur autotrophic reduction nutrition component comprises elemental sulfur; the main component of the iron autotrophic reduction nutrition component comprises ferrous oxide. The composite nutritional reducing microorganism filler can be used for efficiently treating perchlorate.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular, to a composite nutrient reducing microbial filler and a preparation method thereof, a composite nutrient reducing microbial fluidized bed and applications thereof; more particularly, to a composite nutrient reducing microbial filler and a preparation method thereof, a composite nutrient reducing microbial fluidized bed, wastewater treatment equipment and applications thereof. Background Art

[0002] Fireworks wastewater usually contains a small amount of suspended particulate matter (SS), organic pollutants (COD), and a large amount of perchlorate. How to efficiently remove perchlorate from firecracker wastewater is a difficult problem in the field of firecracker wastewater treatment. - ) is a new type of persistent environmental pollutant. The recommended concentration of perchlorate in drinking water is less than 1μg / L. Perchlorate is a strong oxidant and is often used in the manufacture of fireworks and firecrackers, blasting operations and other fields. In addition, fertilizers made from Chilean saltpeter used in agricultural production also contain a certain concentration of perchlorate. Perchlorate has the characteristics of high water solubility, low adsorption, high stability and high mobility and diffusion. Therefore, perchlorate that enters the environmental medium will spread rapidly with surface water and groundwater, causing environmental pollution problems. The pollution status of perchlorate in surface water, groundwater and even drinking water cannot be ignored.

[0003] Physical separation, chemical reduction and other physicochemical methods are hot areas of research on perchlorate removal processes, which can achieve stable and efficient removal of perchlorate. 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 biological reduction process section in traditional biochemical processes to achieve perchlorate removal. However, with the improvement of emission standards, the content of organic matter in 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 biological reduction step, and additional carbon sources are required as electron donors to ensure the smooth progress of the biological reduction process. This will not only greatly increase the cost of wastewater treatment, but also may 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). Based on the above background, the use of inorganic elements as supplementary electron donors combined with organic matter in water to form a composite nutrient-based biological reduction reaction has gradually become an attractive option for reducing perchlorate emissions.

[0004] Perchlorate-reducing bacteria can use the catalytic action of specific reductases under anaerobic / anoxic conditions to reduce perchlorate to chloride ions using perchlorate as an electron acceptor, thereby achieving biological reduction of perchlorate. Perchlorate-reducing bacteria first use perchlorate reductase or chlorate reductase to convert ClO4 - and ClO3 - Reduction to ClO2 - Finally, under the action of chlorite dismutase, non-toxic and harmless Cl - , and releases O2.

[0005] Perchlorate-reducing bacteria are ubiquitous in nature, and have been found in a variety of different environmental media, from river sediments to urban sewage treatment plants, hot springs, gold mine wastewater sediments, deep unsaturated vadose zones, underground gas storage facilities, and even Antarctic soil samples. Currently, many types of perchlorate-reducing bacteria have been isolated and purified. Generally, perchlorate-reducing mixed bacteria or pure bacteria can use perchlorate, chlorate, and nitrate as electron acceptors for respiration.

[0006] Autotrophic perchlorate-reducing bacteria can utilize elemental sulfur (S 0 ), hydrogen (H2) and zero-valent iron (Fe 0 ) and other reduced inorganic electron donors to reduce perchlorate. The autotrophic reduction of perchlorate has received more and more attention because it can effectively avoid the secondary pollution problem caused by excessive addition of organic matter. The prior art mentions that the use of H2 as an electron donor for biological autotrophic reduction of perchlorate in water has a good perchlorate removal effect. However, the application cost of H2 in actual engineering is high, and it is dangerous and explosive, and difficult to store and transport. At the same time, the reduced Fe compounds are easily oxidized, which affects the perchlorate reduction effect. In addition, elemental sulfur S 0 Although it has the advantages of being cheap and stable, it will cause the alkalinity of the effluent to decrease and SO4 2- increase.

[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 composite nutritional reducing microbial filler, which is based on a biochar carrier and contains ferrous oxide and reducing elemental sulfur S 0 As a nutrient supplement for autotrophic biological reduction, it can provide nutrients and achieve efficient treatment of perchlorate. It solves the problems of high H2 application cost, dangerous and explosive, difficult storage and transportation, and the easy oxidation of reduced Fe compounds, which affects the removal effect of perchlorate. It can also alleviate the reduction of alkalinity and SO4 2- increase.

[0009] The second object of the present invention is to provide a method for preparing the above-mentioned composite nutritional reducing microorganism filler, and the composite nutritional reducing microorganism filler prepared by the method has a high removal rate for perchlorate.

[0010] The third object of the present invention is to provide a composite nutrient reducing microbial fluidized bed, which can achieve deep treatment of perchlorate and firecracker wastewater.

[0011] A fourth object of the present invention is to provide a wastewater treatment device having a high removal rate for perchlorate, SS and COD.

[0012] The fifth object of the present invention is to provide a composite nutrition type reducing microorganism filler, a composite nutrition type reducing microorganism fluidized bed or a wastewater treatment equipment for use in treating firecracker wastewater.

[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 composite nutritional reducing microbial filler, which includes a biochar carrier, and a sulfur autotrophic reducing nutritional component and an iron autotrophic reducing nutritional component loaded on the biochar carrier; wherein the mass ratio of the biochar carrier, the sulfur autotrophic reducing nutritional component and the iron autotrophic reducing nutritional component is 90-95:3-7:1-5; the main component of the sulfur autotrophic reducing nutritional component includes elemental sulfur; the main component of the iron autotrophic reducing nutritional component includes ferrous oxide.

[0015] Furthermore, the mass ratio of the biochar carrier, the sulfur autotrophic reducing nutritional component and the iron autotrophic reducing nutritional component is 91-93:4-6:2-4.

[0016] Furthermore, the density of the biochar carrier is less than or equal to 0.9 g / cm 3 .

[0017] Furthermore, the particle size distribution range of the biochar carrier is 4 to 8 mm.

[0018] Furthermore, the biochar carrier is mainly made of at least one of straw, bamboo, walnut shell and coconut shell through oxygen-isolated firing.

[0019] The present invention further provides a method for preparing the composite nutritional reducing microbial filler, comprising the following steps: immersing a biochar carrier in an iron source solution to obtain a biochar carrier loaded with an iron source; calcining the biochar carrier loaded with an iron source in an oxygen-free state to obtain a ferrous oxide-biochar carrier composite material; mixing the ferrous oxide-biochar carrier composite material with molten sulfur, and cooling to obtain the composite nutritional reducing microbial filler.

[0020] Furthermore, the biochar carrier is washed and dried.

[0021] Furthermore, the iron source solution includes ferrous nitrate solution.

[0022] Furthermore, the molar concentration of the iron source solution is 0.05-0.5 mol / L.

[0023] Furthermore, the soaking time is 8 to 24 hours.

[0024] Furthermore, before the oxygen-isolated calcination, the method further includes washing and drying the biochar carrier loaded with the iron source.

[0025] Furthermore, the temperature of the oxygen-isolated calcination is 500-600°C.

[0026] Furthermore, the oxygen-isolated calcination time is 2 to 4 hours.

[0027] Furthermore, the method for preparing the molten sulfur includes: heating the sulfur to 125-150° C. to melt the sulfur into a liquid state.

[0028] The present invention further provides a composite nutrition type reducing microorganism fluidized bed, using the composite nutrition type reducing microorganism filler.

[0029] The present invention further provides a wastewater treatment equipment, comprising a suspended particle treatment section, an organic pollutant treatment section and a perchlorate treatment section which are connected in sequence; wherein the suspended particle treatment section comprises a coagulation tank and a sedimentation tank which are connected; the organic pollutant treatment section comprises an aeration tank; the perchlorate treatment section comprises the composite nutrient type reducing microorganism fluidized bed, and the composite nutrient type reducing microorganism fluidized bed is respectively connected to a dosing tank and an MBR membrane tank.

[0030] Furthermore, the coagulation tank includes a first stirring device.

[0031] Furthermore, the aeration tank includes a second stirring device and an air distribution device; wherein the air distribution device is connected to the fan through a pipeline.

[0032] Furthermore, the composite nutrient reducing microorganism fluidized bed comprises a third stirring device.

[0033] Furthermore, the dosing pool includes a fourth stirring device.

[0034] Furthermore, the MBR membrane tank includes an MBR component.

[0035] Furthermore, the coagulation tank is connected to a water inlet pipe on a side away from the sedimentation tank, and a water inlet pump and a flow meter are provided on the water inlet pipe.

[0036] Furthermore, a dosing pump is provided between the dosing pool and the composite nutrient reducing microorganism fluidized bed.

[0037] Furthermore, the MBR membrane tank is connected to the inlet of the aeration tank through a pipeline via a sludge return pump.

[0038] Furthermore, the wastewater treatment equipment also includes an electric control cabinet.

[0039] Furthermore, the reaction time in the fluidized bed of the composite nutritional reducing microorganisms is 30 to 240 minutes.

[0040] The present invention also provides an application of the composite nutrient reducing microorganism filler, the composite nutrient reducing microorganism fluidized bed, or the wastewater treatment equipment in treating firecracker wastewater; wherein the firecracker wastewater includes suspended particulate matter, organic pollutants and perchlorate.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) The composite nutrient reducing microbial filler provided by the present invention can efficiently treat perchlorate and firecracker wastewater.

[0043] (2) The composite nutrient-reducing microbial filler provided by the present invention has a wide range of applications, low cost, and can effectively avoid secondary pollution problems caused by excessive addition of organic matter.

[0044] (3) The preparation method of the composite nutritional reducing microbial filler provided by the present invention has the advantages of simple operation, short process, low cost, and suitability for mass production.

[0045] (4) The composite nutrient reducing microbial fluidized bed provided by the present invention can achieve deep treatment of firecracker wastewater.

[0046] (5) The wastewater treatment equipment provided by the present invention has a high removal rate for perchlorate, SS and COD. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] 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.

[0048] Figure 1 This is a schematic structural diagram of the wastewater treatment equipment provided by the present invention.

[0049] Reference numerals:

[0050] 100-suspended particle treatment section; 101-coagulation tank; 102-sedimentation tank; 103-first stirring device; 200-organic pollutant treatment section; 201-aeration tank; 202-second stirring device; 203-air distribution device; 204-fan; 300-perchlorate treatment section; 301-complex nutrient reducing microbial fluidized bed; 302-dosing tank; 303-MBR membrane tank; 304-third stirring device; 305-fourth stirring device; 306-MBR component; 307-dosing pump; 308-sludge return pump; 400-water inlet pipe; 401-water inlet pump; 402-flow meter; 500-electric control cabinet. DETAILED DESCRIPTION

[0051] 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.

[0052] In the first aspect, the present invention provides a composite nutritional reducing microbial filler, which is mainly used to treat firecracker wastewater, which includes suspended particulate matter, organic pollutants and perchlorate. Specifically, the composite nutritional reducing microbial filler includes a biochar carrier, and sulfur autotrophic reducing nutrient components and iron autotrophic reducing nutrient components loaded on the biochar carrier.

[0053] Among them, the mass ratio of the biochar carrier, the sulfur autotrophic reducing nutrient component and the iron autotrophic reducing nutrient component is 90-95 (including but not limited to any one of 90, 91, 92, 93, 94, 95 or the range value between any two): 3-7 (including but not limited to any one of 3, 4, 5, 6, 7 or the range value between any two): 1-5 (including but not limited to any one of 1, 2, 3, 4, 5 or the range value between any two).

[0054] The main component of the sulfur autotrophic reducing nutritional component includes elemental sulfur.

[0055] The main component of the iron autotrophic reducing nutritional component includes ferrous oxide.

[0056] Among them, the biochar carrier can provide a growth place for the microbial community, and can slowly release an organic carbon source to provide nutrients for heterotrophic reducing microorganisms; and the biochar carrier has a certain conductivity, which can enhance the efficiency of electron transfer between microbial species, thereby enhancing the efficiency of biological reduction. Sulfur autotrophic reducing nutritional components can provide nutrients for sulfur autotrophic reducing microorganisms. Iron autotrophic reducing nutritional components can provide nutrients for iron autotrophic reducing microorganisms. The present invention is based on sulfur autotrophy as the main body, heterotrophy (organic matter as an electron donor) and iron autotrophy (ferrous oxide as an electron donor) auxiliary reactions.

[0057] When running a process based on sulfur autotrophic reduction, adding a small amount of nutrients for heterotrophic reduction or iron autotrophic reduction can reduce alkalinity and SO4 2- The invention reduces the generation of sulfate and the consumption of alkalinity by adding biochar carrier and iron autotrophic reduction nutrient components with the help of these two auxiliary reactions.

[0058] The composite nutrient reducing microbial filler provided by the present invention is based on a biochar carrier and contains ferrous oxide and reducing elemental sulfur S 0 As a nutrient supplement for autotrophic biological reduction, it provides nutrients to achieve efficient reduction and deep treatment of perchlorate. In addition, the composite nutrient-reducing microbial filler has a wide range of applications, low cost, and can effectively avoid secondary pollution caused by excessive addition of organic matter.

[0059] The composite nutrient-reducing microbial filler provided by the present invention has internal nutrients that are slowly consumed by the biofilm formed on the surface of the filler. Compared with the prior art, the filler can greatly reduce the waste of medicines.

[0060] In some specific embodiments, in order to further improve the reduction effect on perchlorate, the mass ratio of the biochar carrier, the sulfur autotrophic reducing nutritional component and the iron autotrophic reducing nutritional component is 91-93:4-6:2-4.

[0061] In some specific embodiments, the density of the biochar carrier is less than or equal to 0.9 g / cm 3 . Preferably less than or equal to 0.9g / cm 3 And greater than or equal to 0.5g / cm 3 . This density facilitates the operation of the fluidized bed.

[0062] In some specific embodiments, the particle size distribution range of the biochar carrier is 4 to 8 mm. If the particle size is too small, it is difficult to retain and is easily washed away by water flow; if the particle size is too large, the filler specific surface area will be low.

[0063] In some specific embodiments, the biochar carrier is mainly made of at least one of straw, bamboo, walnut shell, and coconut shell through oxygen isolation. Among them, the straw includes corn straw for example. The biochar carrier uses agricultural waste as raw material, which conforms to the concept of "waste treatment with waste". Among them, oxygen isolation refers to the isolation of oxygen (including air).

[0064] In some specific embodiments, the composite nutrient reducing microorganism filler can be used as a biological filler in the form of a fluidized bed. Compared with a fixed bed, a fluidized bed has a higher mass transfer efficiency.

[0065] It is understandable that during storage and transportation of composite nutritional reducing microbial fillers, high-temperature items should be avoided as much as possible.

[0066] In a second aspect, the present invention provides a method for preparing the composite nutritional reducing microbial filler, comprising the following steps:

[0067] The biochar carrier is immersed in an iron source solution and taken out after a period of time to obtain a biochar carrier loaded with the iron source.

[0068] The biochar carrier loaded with the iron source is calcined in an oxygen-free state, and after cooling, a ferrous oxide-biochar carrier composite material is obtained, wherein oxygen-free state refers to the isolation of oxygen (including air).

[0069] The ferrous oxide-biochar carrier composite material is mixed with molten (liquid) sulfur and cooled to obtain the composite nutritional reducing microbial filler.

[0070] The preparation method of the composite nutrient-type reducing microbial filler provided by the present invention has the advantages of simple operation, short process, low cost, and suitability for batch production.

[0071] Compared with other electron donors, elemental sulfur has the advantages of low price and high mass transfer efficiency. In addition, elemental sulfur can be molten after being heated at normal pressure, which is convenient for granulation processing.

[0072] Although the sulfur autotrophic bioreduction process solves the problems of conventional heterotrophic bioreduction processes, such as the need for an external carbon source and high energy consumption, it still has its disadvantages, such as the generation of a certain amount of sulfate and the need to consume a certain amount of alkalinity. Based on this, the present invention introduces a small amount of organic matter and iron elements into the sulfur autotrophic bioreduction system, and utilizes partial heterotrophic bioreduction and iron autotrophic bioreduction reactions to reduce the generation of sulfate and the consumption of alkalinity.

[0073] Biochar is a carbon-based material generated by oxygen-free pyrolysis of waste biomass. In terms of the source of raw materials, biochar is a relatively low-cost carbon-based material with waste utilization properties. In addition to having good physical and chemical properties (such as large specific surface area), biochar will slowly release soluble organic matter in the water body as a nutrient source for heterotrophic reduction. In addition, the good electrical conductivity of biochar can also promote electron transfer between microorganisms and accelerate the rate of biochemical reactions.

[0074] In some specific embodiments, the biochar carrier is washed and dried.

[0075] In some specific embodiments, the iron source solution includes ferrous nitrate solution.

[0076] In some specific embodiments, the molar concentration of the iron source solution is 0.05-0.5 mol / L, including but not limited to any point value of 0.05 mol / L, 0.08 mol / L, 0.1 mol / L, 0.13 mol / L, 0.15 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L or any range value between two of them. This concentration is conducive to the loading of iron on the biochar carrier.

[0077] In some specific embodiments, the soaking time is 8 to 24 hours, including but not limited to any one of 8 hours, 9 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, 22 hours, and 24 hours, or any range between two of them. The soaking time is conducive to fully loading the iron element on the biochar carrier.

[0078] It can be understood that the loading amount of the iron element can be controlled by controlling the concentration of the ferrous nitrate solution and the soaking time.

[0079] In some specific embodiments, before the oxygen-free calcination, the biochar carrier loaded with the iron source is further included in the steps of washing and drying.

[0080] In some specific embodiments, the temperature of the oxygen-isolated calcination is 500-600°C, including but not limited to any point value of 500°C, 520°C, 530°C, 550°C, 560°C, 580°C, 600°C or a range between any two of them.

[0081] In some specific embodiments, the oxygen-isolated calcination time is 2 to 4 hours, including but not limited to any one of 2 hours, 3 hours, and 4 hours, or a range between any two of them.

[0082] In some specific embodiments, the method for preparing molten sulfur includes: heating sulfur to 125-150° C. (including but not limited to any one of 125° C., 130° C., 135° C., 140° C., 145° C., 150° C. or any range between two thereof) to melt the sulfur into a liquid state.

[0083] In a third aspect, the present invention provides a composite nutrient reducing microorganism fluidized bed 301, using the composite nutrient reducing microorganism filler.

[0084] By using the composite nutrient reducing microorganism filler provided by the present invention as a nutrient to drive the operation of the composite nutrient reducing microorganism fluidized bed, deep treatment of perchlorate and firecracker wastewater can be achieved.

[0085] In a fourth aspect, the present invention provides a wastewater treatment device, specifically a firecracker wastewater treatment device, which is mainly used to treat firecracker wastewater, and includes a suspended particle treatment section 100 (SS treatment section), an organic pollutant treatment section 200 (COD treatment section) and a perchlorate treatment section 300 connected in sequence. Figure 1 , which is a structural schematic diagram of wastewater treatment equipment.

[0086] Among them, the main process of the suspended particulate matter treatment section 100 (SS treatment section) is the coagulation and sedimentation process, the main process of the organic pollutant treatment section 200 (COD treatment section) is the aerobic biological process, and the main process of the perchlorate treatment section 300 is the mixed nutrition biological reduction process and the MBR process.

[0087] The suspended particle treatment section 100 includes a coagulation tank 101 and a sedimentation tank 102 which are connected to each other; the coagulation tank 101 and the sedimentation tank 102 are connected by a pipeline. The coagulation tank 101 is mainly used for mixing and coagulating firecracker wastewater and coagulant. The sedimentation tank 102 is mainly used for standing, settling and separating the mixed flocs.

[0088] The organic pollutant treatment section 200 includes an aeration tank 201. The sedimentation tank 102 is connected to the aeration tank 201 through a pipeline. The aeration tank 201 is mainly used to remove COD components in the firecracker wastewater.

[0089] The perchlorate treatment section 300 includes the composite nutrition type reducing microorganism fluidized bed 301, and the composite nutrition type reducing microorganism fluidized bed 301 is connected to the dosing tank 302 and the MBR membrane tank 303 respectively. That is, the aeration tank 201 is connected to the composite nutrition type reducing microorganism fluidized bed 301 through a pipeline, the composite nutrition type reducing microorganism fluidized bed 301 is connected to the dosing tank 302 through a pipeline, and the composite nutrition type reducing microorganism fluidized bed 301 is connected to the MBR membrane tank 303 through a pipeline. Among them, the composite nutrition type reducing microorganism fluidized bed 301 and the MBR membrane tank 303 are mainly used to remove the perchlorate component in the firecracker wastewater. The dosing tank 302 is mainly used to add sodium bicarbonate and trace elements to the composite nutrition type reducing microorganism fluidized bed 301.

[0090] That is, the wastewater treatment equipment includes an inlet pipe 400, a coagulation tank 101, a sedimentation tank 102, an aeration tank 201 and a compound nutrient-reducing microbial fluidized bed 301 which are connected in sequence, and the compound nutrient-reducing microbial fluidized bed 301 is connected to a dosing tank 302 and an MBR membrane tank 303, respectively.

[0091] Among them, the wastewater treatment equipment mainly achieves the deep removal of perchlorate in firecracker wastewater through compound nutrient-based biological reduction technology.

[0092] The wastewater treatment equipment provided by the present invention has a high removal rate for perchlorate, SS and COD, and also has the advantages of high mass transfer efficiency, strong biological affinity, high degree of automation, strong operability, and is not prone to secondary pollution.

[0093] In addition, the composite nutrient-type reducing microbial filler for treating firecracker wastewater provided by the present invention can be replaced in time according to the consumption situation. Compared with the prior art, it can greatly reduce the problems of filler blockage. 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, which makes it difficult to replace it in time according to the actual consumption of each part. The technology of the present invention adopts the form of fluidized bed biological filler. During operation, all fillers are always in a fluidized state, so the consumption degree is consistent. 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.

[0094] It is understandable that the composite nutrient reducing microbial filler is a consumable biological filler, and its weight and volume will slowly decrease during use, so it needs to be replenished regularly.

[0095] In some specific implementations, the coagulation tank 101 includes a first stirring device 103 ; wherein the first stirring device 103 is used to stir the material in the coagulation tank 101 .

[0096] In some specific implementations, the aeration tank 201 includes a second stirring device 202 and an air distribution device 203, wherein the air distribution device 203 is connected to the fan 204 through a pipeline. The second stirring device 202 is used to stir the material in the aeration tank 201. The air distribution device 203 is used for aeration.

[0097] In some specific implementations, the composite nutrient reducing microorganism fluidized bed 301 includes a third stirring device 304 ; wherein the third stirring device 304 is used to stir the materials in the composite nutrient reducing microorganism fluidized bed 301 .

[0098] In some specific implementations, the dosing pool 302 includes a fourth stirring device 305 ; wherein the fourth stirring device 305 is used to stir the material in the dosing pool 302 .

[0099] In some specific implementations, the MBR membrane pool 303 includes an MBR component 306 ; and the effluent of the wastewater treatment equipment is discharged from the outlet of the MBR component 306 .

[0100] In some specific implementations, the coagulation tank 101 is connected to a water inlet pipe 400 on a side away from the sedimentation tank 102, and the water inlet pipe 400 is used to input firecracker wastewater. The water inlet pipe 400 is provided with a water inlet pump 401 and a flow meter 402. The flow meter 402 is provided between the water inlet pump 401 and the coagulation tank 101, and the water inlet pump 401 and the flow meter 402 jointly regulate the water inlet flow entering the subsequent unit.

[0101] In some specific implementations, a dosing pump 307 is provided between the composite nutrient reducing microorganism fluidized bed 301 and the dosing pool 302 .

[0102] In some specific implementations, the MBR membrane pool 303 is connected to the inlet of the aeration pool 201 through a pipeline via a sludge return pump 308. The MBR pool is used to intercept microorganisms (or sulfur autotrophic bioreduction sludge) to prevent them from being lost.

[0103] In some specific implementations, the wastewater treatment equipment further includes an electric control cabinet 500. The electric control cabinet 500 is responsible for controlling the working state of each unit in the device and is connected to corresponding devices or components, such as various stirring devices, various pumps, and the like.

[0104] In some specific embodiments, the reaction time in the composite nutrient reducing microorganism fluidized bed 301 is 30 to 240 minutes, including but not limited to any one of 30 minutes, 60 minutes, 90 minutes, 120 minutes, 180 minutes, and 240 minutes, or a range between any two of them.

[0105] In some specific embodiments, the reaction time of each reaction tank in the wastewater treatment equipment is 30 min to 240 min, including but not limited to any point value of 30 min, 60 min, 90 min, 120 min, 180 min, 240 min or a range value between any two of them.

[0106] In some specific implementations, the dissolved oxygen concentration in the aeration tank 201 (ie, aerobic tank) is in the range of DO=1-4 mg / L, for example, 2 mg / L or 3 mg / L.

[0107] In some specific implementations, the dissolved oxygen concentration in the composite nutrient reducing microorganism fluidized bed 301 is in the range of DO≤0.5 mg / L.

[0108] The working principle of the wastewater treatment equipment is as follows: the firecracker wastewater is pumped into the equipment through the water inlet pump 401, and passes through the coagulation tank 101, the sedimentation tank 102, the aeration tank 201, the composite nutrient reduction microbial fluidized bed 301 and the MBR membrane tank 303 in sequence to complete the removal of suspended particles (SS), organic pollutants (COD) and perchlorate in the wastewater. The treated wastewater flows through the MBR component 306 and is discharged from the device. The entire equipment is controlled by the electric control cabinet 500. The dosage and type of the dosing are determined according to the perchlorate concentration in the wastewater to be treated, and the present invention does not limit this.

[0109] In a fifth aspect, the present invention provides the use of the composite nutrient reducing microorganism filler, the composite nutrient reducing microorganism fluidized bed 301 or the wastewater treatment equipment in treating firecracker wastewater; wherein the firecracker wastewater includes suspended particulate matter, organic pollutants and perchlorate.

[0110] The above-mentioned composite nutrient reducing microorganism filler, composite nutrient reducing microorganism fluidized bed 301 and wastewater treatment equipment can achieve efficient and deep treatment of perchlorate.

[0111] 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.

[0112] Example 1

[0113] This embodiment provides a method for preparing a composite nutritional reducing microbial filler, comprising the following steps:

[0114] (1) Obtaining a biochar carrier having a density of 0.9 g / cm 3 , the particle size distribution range is 4 to 8 mm, and the biochar carrier is made of straw by oxygen-free burning. The biochar carrier is fully rinsed with deionized water and then dried, and then the dried biochar carrier is soaked in a 0.1 mol / L ferrous nitrate solution, and taken out after soaking for 8 hours to obtain a biochar carrier loaded with an iron source. It can be understood that by controlling the concentration of the ferrous nitrate solution and the soaking time, the loading amount of the iron element can be controlled.

[0115] (2) The biochar carrier loaded with the iron source obtained in step (1) is washed with water and dried, and then placed in a muffle furnace and calcined at 550° C. in an oxygen-free environment for 2 h. After cooling, the mixture is collected to obtain a ferrous oxide-biochar carrier composite material.

[0116] (3) placing sulfur in a heated container with ventilation conditions, raising the heating temperature to 140° C., and after the sulfur is fully melted, slowly pouring the molten sulfur into a block mold, and adding the ferrous oxide-biochar carrier composite material obtained in step (2) thereto, mixing evenly, and obtaining a composite nutritional reducing microbial filler after cooling.

[0117] The composite nutritional reducing microbial filler prepared in this embodiment includes a biochar carrier and a sulfur autotrophic reducing nutritional component and an iron autotrophic reducing nutritional component loaded on the biochar carrier; wherein the mass ratio of the biochar carrier, the sulfur autotrophic reducing nutritional component, and the iron autotrophic reducing nutritional component is 92:5:3. The main component of the sulfur autotrophic reducing nutritional component is elemental sulfur. The main component of the iron autotrophic reducing nutritional component is ferrous oxide.

[0118] Example 2

[0119] The preparation method of the composite nutritional reducing microbial filler provided in this embodiment comprises the following steps:

[0120] (1) Obtaining a biochar carrier having a density of 0.8 g / cm 3 The particle size is 6-8 mm, and the biochar carrier is made of straw by oxygen-free burning. The biochar carrier is fully rinsed with deionized water and then dried, and then the dried biochar carrier is immersed in a 0.05 mol / L ferrous nitrate solution, and then taken out after immersion for 12 hours to obtain a biochar carrier loaded with an iron source.

[0121] (2) The biochar carrier loaded with the iron source obtained in step (1) is washed with water and dried, and then placed in a muffle furnace and calcined at 600° C. for 2 h in an oxygen-free state. After cooling, the mixture is collected to obtain a ferrous oxide-biochar carrier composite material.

[0122] (3) placing sulfur in a heated container with ventilation conditions, raising the heating temperature to 150° C., and after the sulfur is fully melted, slowly pouring the molten sulfur into a block mold, and adding the ferrous oxide-biochar carrier composite material obtained in step (2) thereto, mixing evenly, and obtaining a composite nutritional reducing microbial filler after cooling.

[0123] The composite nutritional reducing microbial filler prepared in this embodiment includes a biochar carrier and a sulfur autotrophic reducing nutritional component and an iron autotrophic reducing nutritional component loaded on the biochar carrier; wherein the mass ratio of the biochar carrier, the sulfur autotrophic reducing nutritional component, and the iron autotrophic reducing nutritional component is 92:5:2. The main component of the sulfur autotrophic reducing nutritional component is elemental sulfur. The main component of the iron autotrophic reducing nutritional component is ferrous oxide.

[0124] Example 3

[0125] The preparation method of the composite nutrient-reducing microbial filler provided in this embodiment comprises the following steps:

[0126] (1) Obtaining a biochar carrier having a density of 0.8 g / cm 3 The particle size is 5 to 7 mm, and the biochar carrier is made of straw by oxygen-free burning. The biochar carrier is fully rinsed with deionized water and then dried, and then the dried biochar carrier is immersed in a 0.25 mol / L ferrous nitrate solution, and taken out after immersion for 8 hours to obtain a biochar carrier loaded with an iron source.

[0127] (2) The biochar carrier loaded with the iron source obtained in step (1) is washed with water and dried, and then placed in a muffle furnace and calcined at 500° C. for 4 h in an oxygen-free state. After cooling, the mixture is collected to obtain a ferrous oxide-biochar carrier composite material.

[0128] (3) placing sulfur in a heated container with ventilation conditions, raising the heating temperature to 130° C., and after the sulfur is fully melted, slowly pouring the molten sulfur into a block mold, and adding the ferrous oxide-biochar carrier composite material obtained in step (2) thereto, mixing evenly, and obtaining a composite nutritional reducing microbial filler after cooling.

[0129] The composite nutritional reducing microbial filler prepared in this embodiment includes a biochar carrier and a sulfur autotrophic reducing nutritional component and an iron autotrophic reducing nutritional component loaded on the biochar carrier; wherein the mass ratio of the biochar carrier, the sulfur autotrophic reducing nutritional component, and the iron autotrophic reducing nutritional component is 92:5:5. The main component of the sulfur autotrophic reducing nutritional component is elemental sulfur. The main component of the iron autotrophic reducing nutritional component is ferrous oxide.

[0130] Example 4

[0131] The preparation method of the composite nutritional reducing microbial filler provided in this embodiment is basically the same as that in Example 1, except that in step (3), a corresponding mass of sulfur is weighed and melted according to a mass ratio of the biochar carrier to the sulfur autotrophic reducing nutritional component of 92:7. In the composite nutritional reducing microbial filler prepared in this embodiment, the mass ratio of the biochar carrier, the sulfur autotrophic reducing nutritional component, and the iron autotrophic reducing nutritional component is 92:7:3.

[0132] Example 5

[0133] The preparation method of the composite nutritional reducing microbial filler provided in this embodiment is basically the same as that in embodiment 1, except that: in step (3), the corresponding mass of sulfur is weighed and melted according to the mass ratio of the biochar carrier to the sulfur autotrophic reducing nutritional component of 92:4. In the composite nutritional reducing microbial filler prepared in this embodiment, the mass ratio of the biochar carrier, the sulfur autotrophic reducing nutritional component, and the iron autotrophic reducing nutritional component is 92:4:3.

[0134] Example 6

[0135] The preparation method of the composite nutrient reducing microbial filler provided in this embodiment is basically the same as that in embodiment 1, except that the biochar carrier in step (1) is different. The density of the biochar carrier used in this embodiment is 1.0 g / cm 3 , the particle size distribution range is 5 to 8 mm, and the biochar carrier is made of coconut shell by oxygen-free firing.

[0136] Example 7

[0137] This embodiment provides a firecracker wastewater treatment device, such as Figure 1As shown, it includes a water inlet pipe 400, a suspended particle treatment section 100, an organic pollutant treatment section 200 and a perchlorate treatment section 300 which are connected in sequence. The suspended particle treatment section 100 includes a coagulation tank 101 and a sedimentation tank 102 which are connected in sequence with the water inlet pipe 400. The coagulation tank 101 is provided with a first stirring device 103, which is used to stir the mixed liquid inside the coagulation tank 101. The organic pollutant treatment section 200 includes an aeration tank 201 which is connected with the sedimentation tank 102. The aeration tank 201 is provided with a second stirring device 202 and an air distribution device 203, and the air distribution device 203 is connected to the fan 204 through a pipeline. The perchlorate treatment section 300 is connected to the aeration tank 201 and includes a composite nutrient type reducing microorganism fluidized bed 301, in which the composite nutrient type reducing microorganism filler prepared in Example 1 is arranged, and the composite nutrient type reducing microorganism fluidized bed 301 is also provided with a third stirring device 304. The composite nutrient type reducing microorganism fluidized bed 301 is respectively connected to a dosing tank 302 and an MBR membrane tank 303, wherein the dosing tank 302 is provided with a fourth stirring device 305, and a dosing pump 307 is arranged between the dosing tank 302 and the composite nutrient type reducing microorganism fluidized bed 301, and the sodium bicarbonate and trace elements in the dosing tank 302 are added to the composite nutrient type reducing microorganism fluidized bed 301 through the dosing pump 307, so as to provide nutrient elements for biological reduction reaction and treat the firecracker wastewater containing perchlorate; the MBR membrane tank 303 includes an MBR component 306, and the effluent of the wastewater treatment equipment is discharged from the outlet of the MBR component 306. The water inlet pipe 400 is provided with a water inlet pump 401 and a flow meter 402, wherein the flow meter 402 is provided between the water inlet pump 401 and the coagulation tank 101, and the water inlet pump 401 and the flow meter 402 jointly regulate the water inlet flow rate entering the subsequent unit. The MBR membrane tank 303 is connected to the inlet of the aeration tank 201 through a pipeline via a sludge return pump 308. The firecracker wastewater treatment equipment also includes an electric control cabinet 500 for controlling each unit.

[0138] Comparative Example 1

[0139] 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), the ferrous nitrate solution is replaced with a sodium nitrate solution of equimolar concentration, that is, the filler prepared in this comparative example does not contain ferrous oxide.

[0140] Comparative Example 2

[0141] The filler provided in this comparative example is the ferrous oxide-biochar carrier composite material obtained in step (2) of Example 1. That is, the filler in this comparative example does not contain elemental sulfur.

[0142] The daily water treatment capacity of the wastewater treatment workshop of a firecracker production plant is 8000m 3 / d, and its water quality indicators are: SS is about 100mg / L, COD is about 50mg / L, and perchlorate is about 300mg / L (specific indicators are shown in Table 1). The composite nutrient reducing microbial filler prepared in Example 1 and the firecracker wastewater treatment equipment provided in Example 7 are used to treat the perchlorate in the firecracker wastewater. After a period of operation, the effluent is treated relatively stably, and the specific inlet and outlet water quality indicators are shown in Table 1. Sample 1, Sample 2, and Sample 3 in Table 1 refer to different batches of firecracker wastewater.

[0143] Table 1 Comparison of water quality indicators before and after treatment

[0144]

[0145] It can be seen from Table 1 that the composite nutrient reducing microbial filler prepared in Example 1 and the firecracker wastewater treatment equipment provided in this example can achieve a removal rate of more than 95% for perchlorate and SS, and a removal rate of more than 45% for COD.

[0146] Furthermore, the firecracker wastewater treatment equipment provided in Example 7 was used, and the composite nutritional reducing microbial filler prepared in Example 1 was replaced with the composite nutritional reducing microbial fillers prepared in Examples 2 to 6 and the fillers prepared in Comparative Examples 1 to 2, respectively, to treat the firecracker wastewater with perchlorate (i.e., each filler was used for treatment respectively), and the results are shown in Table 2.

[0147] Table 2 Comparison of perchlorate index before and after treatment

[0148]

[0149] It can be seen from Table 2 that the removal rate of perchlorate in firecracker wastewater treated with the composite nutrient reducing microbial filler prepared in each embodiment is relatively high, while the removal rate of perchlorate in each comparative example is relatively low.

[0150] Specifically, since the filler of Comparative Example 1 does not contain ferrous oxide, the sulfur autotrophic reduction sludge in the system occupies a more dominant position, which in turn leads to an increase in the sulfate concentration in the effluent (1734 mg / L for Comparative Example 1 and 1400 mg / L for Example 1), and a lower pH value (6.3 for Comparative Example 1 and 7.8 for Example 1).

[0151] The filler of Comparative Example 2 does not contain elemental sulfur, resulting in a lack of nutrients in the sulfur autotrophic biological reduction sludge, which in turn leads to a significant decrease in the perchlorate removal rate.

[0152] In summary, the composite nutrient-reducing microbial filler provided by the present invention can achieve efficient treatment of perchlorate, with a removal rate of more than 95%.

[0153] Moreover, the firecracker wastewater treatment equipment provided by the present invention also has relatively high removal rates for SS and COD, which are respectively above 95% and above 45%.

[0154] 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. A composite nutritional reducing microbial filler, characterized in that: It includes a biochar carrier, and a sulfur autotrophic reduction nutrient component and an iron autotrophic reduction nutrient component loaded on the biochar carrier; Wherein, the mass ratio of the biochar carrier, the sulfur autotrophic reduction nutritional component and the iron autotrophic reduction nutritional component is 90-95:3-7:1-5; The main component of the sulfur autotrophic reducing nutrient component includes elemental sulfur; The main component of the iron autotrophic reducing nutritional component includes ferrous oxide.

2. The composite nutritional reducing microbial filler according to claim 1, characterized in that: The mass ratio of the biochar carrier, the sulfur autotrophic reducing nutritional component and the iron autotrophic reducing nutritional component is 91-93:4-6:2-4.

3. The composite nutritional reducing microbial filler according to claim 1, characterized in that: At least one of the following conditions is met: (1) The density of the biochar carrier is less than or equal to 0.9 g / cm 3 ; (2) The particle size distribution range of the biochar carrier is 4 to 8 mm; (3) The biochar carrier is mainly made of at least one of straw, bamboo, walnut shell and coconut shell through oxygen-free firing.

4. The method for preparing the composite nutritional reducing microbial filler according to any one of claims 1 to 3, characterized in that: The steps include: soaking the biochar carrier in an iron source solution to obtain a biochar carrier loaded with the iron source; calcining the biochar carrier loaded with the iron source in the absence of oxygen to obtain a ferrous oxide-biochar carrier composite material; The ferrous oxide-biochar carrier composite material is mixed with molten sulfur, and after cooling, the composite nutritional reducing microbial filler is obtained.

5. The method for preparing the composite nutritional reducing microbial filler according to claim 4, characterized in that: At least one of the following conditions is met: (1) The biochar carrier is washed and dried; (2) The iron source solution includes ferrous nitrate solution; (3) The molar concentration of the iron source solution is 0.05 to 0.5 mol / L; (4) The soaking time is 8 to 24 hours; (5) Before the oxygen-free calcination, the biochar carrier loaded with the iron source is further included in the steps of washing and drying; (6) The temperature of the oxygen-isolated calcination is 500-600° C.; (7) The oxygen-free calcination time is 2 to 4 hours; (8) The method for preparing molten sulfur comprises: heating sulfur to 125-150° C. to melt sulfur into a liquid state.

6. A composite nutrient reducing microbial fluidized bed, characterized in that: Use the composite nutritional reducing microbial filler as described in any one of claims 1 to 3.

7. Wastewater treatment equipment, characterized in that, It includes a suspended particulate matter treatment section, an organic pollutant treatment section and a perchlorate treatment section which are connected in sequence; Wherein, the suspended particle treatment section includes a coagulation tank and a sedimentation tank connected to each other; The organic pollutant treatment section includes an aeration tank; The perchlorate treatment section comprises the composite nutrient reducing microorganism fluidized bed as claimed in claim 6, and the composite nutrient reducing microorganism fluidized bed is connected to a dosing tank and an MBR membrane tank respectively.

8. The wastewater treatment equipment according to claim 7, characterized in that: At least one of the following conditions is met: (1) The coagulation tank includes a first stirring device; (2) The aeration tank includes a second stirring device and an air distribution device; wherein the air distribution device is connected to the fan through a pipeline; (3) The composite nutrient reducing microorganism fluidized bed includes a third stirring device; (4) The dosing tank includes a fourth stirring device; (5) The MBR membrane tank includes an MBR component; (6) On a side away from the sedimentation tank, the coagulation tank is connected to a water inlet pipe, and the water inlet pipe is provided with a water inlet pump and a flow meter; (7) A dosing pump is provided between the dosing pool and the composite nutrient reducing microorganism fluidized bed; (8) The MBR membrane tank is connected to the inlet of the aeration tank through a pipeline via a sludge return pump; (9) The wastewater treatment equipment also includes an electrical control cabinet.

9. The wastewater treatment equipment according to claim 7, characterized in that: The reaction time in the composite nutrition type reducing microorganism fluidized bed is 30 to 240 minutes.

10. Use of the composite nutritional reducing microorganism filler according to any one of claims 1 to 3, the composite nutritional reducing microorganism fluidized bed according to claim 6, or the wastewater treatment equipment according to claim 7 in treating firecracker wastewater; in, The firecracker wastewater includes suspended particles, organic pollutants and perchlorates.

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