CN118929908A

CN118929908A - Aerated biological filter and treatment method for synergistic treatment of nitrogen, phosphorus and antibiotics

Info

Publication number: CN118929908A
Application number: CN202411070286.0A
Authority: CN
Inventors: 李保菊; 梁英; 范俊; 李爱民; 崔彦兵; 王敏; 陈清; 陈丹; 崔详柯
Original assignee: Nanjing Huachuang Institute Of Environmental Technology Co ltd
Current assignee: Nanjing Huachuang Institute Of Environmental Technology Co ltd
Priority date: 2024-08-06
Filing date: 2024-08-06
Publication date: 2024-11-12

Abstract

The present invention discloses an aerated biological filter and a treatment method for synergistically treating nitrogen, phosphorus and antibiotics, and belongs to the technical field of aquaculture wastewater treatment. The aerated biological filter comprises a tank body, the tank body is provided with a liquid inlet and a liquid outlet, and in the direction from the liquid inlet to the liquid outlet, the tank body is provided with a water distribution area, a supporting layer, a packing layer and a water outlet area in sequence, and the supporting layer is used to support the packing layer; the liquid inlet is arranged in the water distribution area, and the liquid outlet is arranged in the water outlet area; the water distribution area is provided with an aeration pipe, an air inlet, a backwash water inlet and a backwash air inlet; the packing layer is filled with volcanic rock and SENPs filler; in the treatment method of nitrogen, phosphorus and antibiotic wastewater using the biological aerated filter, the volume ratio of volcanic rock and SENPs filler is 3:1 to 5:1. The main purpose of the present invention is to achieve simultaneous denitrification and phosphorus removal and removal of organic matter while effectively reducing the content of antibiotics in wastewater.

Description

Biological aerated filter for cooperatively treating nitrogen, phosphorus and antibiotics and treatment method

Technical Field

The invention relates to the technical field of aquaculture wastewater treatment, in particular to a biological aerated filter for cooperatively treating nitrogen, phosphorus and antibiotics and a treatment method.

Background

Although the use of antibiotics has greatly promoted the development of aquaculture industry, it has also caused the environmental pollution of aquaculture and the problem of drug residue. Researches show that only 20% -30% of antibiotics are absorbed by aquatic animals, and the rest of antibiotics are discharged into the water body in the form of raw medicines or metabolites. At present, the technology for treating domestic and foreign cultivation wastewater is mainly divided into four major categories of physical, chemical, biological and comprehensive treatment technologies. The comprehensive treatment technology combines various treatment technologies, such as physical, chemical and biological technologies, so as to adapt to different treatment requirements and environmental conditions, and realize effective process design, including artificial wetland, three-pond two-dam, land-based three-pond mode, stabilization pond and the like. However, in practical application, the comprehensive treatment technology has very limited degradation effect on antibiotics in the aquaculture wastewater, and cannot effectively remove the antibiotics in the aquaculture wastewater.

The aeration biological filter (BAF for short) is a novel biological membrane method sewage treatment technology, integrates the functions of filtration interception, adsorption, biological membrane degradation and the like, has the advantages of good treatment effect, strong impact load resistance, small occupied area and the like, and is widely applied to the fields of domestic sewage, industrial wastewater and agricultural wastewater treatment. Chinese patent CN117756278A discloses a method for treating freshwater aquaculture sewage and a special device thereof, wherein freshwater aquaculture sewage and a co-metabolism matrix are continuously introduced into a composite aeration biological filter tank, so that the freshwater aquaculture sewage and the co-metabolism matrix sequentially pass through a non-aeration zone, a membrane aeration zone and a foam aeration zone from top to bottom, ceramic grains are filled in the non-aeration zone, the membrane aeration zone and the foam aeration zone, and then a plurality of technological parameters such as membrane aeration pressure of the membrane aeration zone, gas-water ratio of the foam aeration zone, proportion of the co-metabolism matrix and the like are controlled according to the change condition of various indexes of effluent and the growth condition of microorganisms; and an additional dephosphorizing agent is required to be added to realize dephosphorization. Although effective removal of nitrogen and phosphorus and antibiotics is achieved, depending on the addition of co-metabolizing substrates such as acetic acid and phosphorus scavengers, processing costs and the like are increased. The literature (influence mechanism of different pyrolysis temperatures BC on BAF for treating aquaculture wastewater. China environmental science 2023,43 (3): 1131-1141) discloses a method for treating aquaculture wastewater by using biochar prepared by bamboo chip pyrolysis as a filler of an aeration biological filter, and the research shows that BAF with the pyrolysis temperature of 700 ℃ has optimal decontamination efficiency, and the average removal rate of TN and TP reaches 51.99% and 41.00% and the average removal rate of SDZ, SMX, ENR and CIP reaches 71.84%, 75.01%, 62.91% and 69.62% during stable operation. Although biochar has the advantages of wide sources, reproducibility and the like, the removal effect on nitrogen, phosphorus and ENR antibiotics is poor.

Therefore, a biological aerated filter is needed to realize the synchronous removal of pollutants such as nitrogen, phosphorus, antibiotics and the like, and reduce the addition of additional additives such as carbon sources and the like.

Disclosure of Invention

1. Technical problem to be solved by the invention

The invention aims to solve the problems of poor effect of the biological aerated filter in the prior art on simultaneously removing nitrogen, phosphorus and antibiotics in aquaculture wastewater, addition of additional additives such as carbon sources and the like, and provides the biological aerated filter for cooperatively treating the nitrogen, the phosphorus and the antibiotics and a treatment method.

2. Technical proposal

In order to achieve the above purpose, the technical scheme provided by the invention is as follows:

The invention relates to a biological aerated filter, which comprises a tank body,

The tank body is provided with a liquid inlet and a liquid outlet,

The water distribution area, the supporting layer, the packing layer and the water outlet area are sequentially arranged on the tank body from the liquid inlet to the liquid outlet, and the supporting layer is used for supporting the packing layer;

the liquid inlet is arranged in the water distribution area, and the liquid outlet is arranged in the water outlet area;

the water distribution area is provided with an aeration pipe, an air inlet, a back flush water inlet and a back flush air inlet;

The packing layer is filled with volcanic rock and SENPs packing.

The SENPs filler is provided by the Nanjing environmental technology institute of technology, inc., has a particle size of 5-6 mm, a bulk density of 1.2-1.3 g/cm ³, and a porosity of 40-50%.

Further, the volcanic rock has a particle size of 3-5 mm, a bulk density of 3.0-3.1 g/cm ³ and a porosity of 30-40%.

Further, the volcanic rock and SENPs filler are washed and dried before use;

the cleaning can be flushing with distilled water and ultrasonic;

the drying may be oven-dried to constant weight.

For example, the washing may be 3 times with distilled water, and ultrasonic treatment is performed at 25 ℃ for 30min;

The temperature of the drying in the drying may be 60 ℃.

Further, the volume ratio of the water distribution area to the bearing layer to the filler layer to the water outlet area is 20:5:30-50:25.

Further, the aeration pipe is connected with a plurality of microporous aeration filter heads.

Further, the air inlet is connected with an air inlet pipe, the air inlet pipe is connected with an air flowmeter and an air pump, and the aeration pipe is connected with the air inlet pipe.

Further, the liquid inlet is connected with a water inlet pipe, and the water inlet pipe is connected with a water pump.

Further, the supporting layer is filled with filter materials, and the particle size of the filter materials is 20-40 mm.

Further, the filter material is one or two of gravel and cobble.

Preferably, the filter material filled in the bearing layer is filled from the liquid inlet to the liquid outlet according to the particle size of the filter material from large to small.

Further, the back flush water inlet is connected with a back flush water inlet pipe;

the back flush air inlet is connected with a back flush air inlet pipe.

Further, the liquid outlet is connected with a water outlet tank, a baffle is arranged in the water outlet tank, the baffle divides the water outlet tank into a drainage area and a back flushing drainage area, and the back flushing drainage area is close to the tank body.

Further, the volume ratio of the water outlet area to the water outlet pool is 25:3-5.

Further, the height of the top of the baffle is higher than that of the top of the liquid outlet.

Further, the water outlet pool is provided with a top plate, and the height of the top of the baffle is lower than that of the top plate.

Further, the drainage area is connected with a drainage pipe;

And the back flush drainage area is connected with a back flush drainage pipe.

Preferably, the back flush inlet pipe is connected with a water pump, and the back flush inlet pipe is provided with a gas flowmeter.

The invention also provides a treatment method of the wastewater containing nitrogen and phosphorus and antibiotics by using the biological aerated filter, which comprises the following steps:

after the membrane is successfully formed on the biological aerated filter, wastewater enters a tank body of the biological aerated filter through a liquid inlet, sequentially passes through a water distribution area, a supporting layer and a packing layer, and flows out through a liquid outlet of a water outlet area;

wherein the volume ratio of volcanic rock filled by the filler layer to SENPs filler is 3:1-5:1.

Preferably, the volume ratio of volcanic rock filled by the packing layer to SENPs packing is 3.5-4.5; further preferably 4:1.

Further, after the treatment is finished, stopping running the aeration biological filter, and performing back flushing.

Further, the gas-water ratio is 4:1-6:1 during operation, and the hydraulic load is 2-3 m ³/(m². D).

Further, the aeration pipe is also included for aeration,

The aeration mode is continuous aeration, so that the dissolved oxygen range in the wastewater is 1.5 mg/L-2.0 mg/L.

Further, the back flushing is to open the back flushing water inlet pipe and the back flushing air inlet pipe simultaneously.

Further, the wastewater containing nitrogen and phosphorus and antibiotics is aquaculture wastewater.

Further, the treatment method is used for removing antibiotics in aquaculture wastewater.

Further, the treatment method is also used for removing COD _Mn, ammonia nitrogen, total Nitrogen (TN) and Total Phosphorus (TP) in the aquaculture wastewater.

Further, the antibiotics include one, two or more of fluoroquinolone antibiotics, sulfonamide antibiotics or chloramphenicol antibiotics.

Further, the antibiotics are one, two or three of enrofloxacin, sulfamethoxazole or florfenicol.

Preferably, the antibiotic is a fluoroquinolone antibiotic; enrofloxacin is further preferred.

3. Advantageous effects

Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects:

According to the biological aerated filter, the packing layer is filled with volcanic rock and SENPs packing, the volume ratio of the volcanic rock filled with the packing layer to the SENPs packing is 3:1-5:1 in the application of treating the aquaculture wastewater, so that the effective denitrification and dephosphorization and removal of organic matters are realized, meanwhile, antibiotics in the wastewater can be effectively reduced through adsorption interception and microorganism co-metabolism, the concentration of the antibiotics in the treated wastewater in effluent is reduced, and the influence on the environment is reduced; the method has good removal effect on fluoroquinolone antibiotics and sulfonamide antibiotics, wherein the removal effect on enrofloxacin is good; in addition, the additional addition of co-metabolism matrixes, carbon sources and the like is not needed;

Furthermore, the removal rate of enrofloxacin can reach 98.7+/-0.7 percent, and the removal rate is because the surface of volcanic rock is uneven and the specific surface area is large, the surface of SENPs filler is rough and uneven, and the filling material has rich pore structures and provides a large number of adsorption sites. In addition, the ACE index, the Chao index and the Shannon index of the biomembrane formed in the filler area are all larger than those of the biomembrane on the surface of the volcanic filler, which shows that the biomembrane has relatively higher richness and microorganism diversity, and the increase of the filler type can increase the diversity of microorganisms in a system to a certain extent. Chloroflexi (Apolybdenum) is detected in a biological film on the surface of SENPs filler, the ratio is 12.8%, chloroflexi is a facultative anaerobic microorganism, and the biological film has the functions of nitrification, denitrification and dephosphorization, and the detection of the facultative anaerobic microorganism in the biological film indicates that an anaerobic/aerobic microenvironment is formed in the filler biological film, thereby being beneficial to further improving the biodegradation efficiency of antibiotics. Further, the applicant has found from previous experimental studies that SENPs alone was not found Chloroflexi when used as a filler film. And ENR has high hydrophilicity, is easy to photolyze and is easy to be adsorbed. Therefore, after the wastewater containing antibiotics enters the reactor, the stuffing and the biological film attached to the surface of the stuffing adsorb ENR, and meanwhile, the metabolism degradation effect of microorganisms and the co-metabolism effect of the nitrification process are also beneficial to the degradation of part of ENR, so that the ENR is efficiently reduced.

Drawings

FIG. 1 shows a biological aerated filter according to embodiment 1 of the invention;

FIG. 2 is a blend of volcanic rock and SENPs filler in example 2 of the present invention;

FIG. 3 is a view showing the removal of contaminants in a biological aerated filter for simulating a steady operation stage of wastewater from cultivation in example 2 of the present invention:

(a)COD_Mn;(b)NH₃-N；(c)TN；(d)TP；

FIG. 4A simulation of the concentration change and removal rate of antibiotics ENR, SMX, FLO in aquaculture wastewater according to example 2 of the present invention:

(a) ENR; (b) SMX; (c) FLO; (d) ENR, SMX, FLO removal rate.

Reference numerals in the schematic drawings illustrate:

1. A cell body; 2. a filler layer; 3. a support layer; 4. a water inlet pipe; 5. a water pump; 6. an air inlet pipe; 7. an air pump; 8. a gas flow meter; 9. back flushing the water inlet pipe; 10. back flushing the air inlet pipe; 11. an aeration pipe; 12. a drainage area; 13. back flushing the drainage area; 14. a drain pipe; 15. back flushing the drain pipe; 16. a water outlet area; 17. a water distribution area; 18. a baffle; 19. a top plate; 20. and (5) discharging the water from the water tank.

Detailed Description

The present disclosure may be understood more readily by reference to the following description taken in conjunction with the examples, all of which form a part of this disclosure. It is to be understood that this disclosure is not limited to the particular products, methods, conditions, or parameters described and/or shown herein. Further, the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting unless otherwise indicated.

It is also to be appreciated that certain features of the disclosure may, for clarity, be described herein in the context of separate embodiments, but may also be provided in combination with each other in a single embodiment. That is, each separate embodiment is contemplated to be combinable with any other embodiment, and to be considered as representing a different embodiment, unless expressly incompatible or specifically excluded. Conversely, various features of the disclosure that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Finally, although a particular embodiment may be described as part of a series of steps or as part of a more general structure, each step or sub-structure itself may also be considered a separate embodiment.

Unless otherwise indicated, it should be understood that each individual element in the list and each combination of individual elements in the list are to be construed as different embodiments. For example, a list of embodiments denoted as "A, B or C" should be interpreted to include embodiments "a", "B", "C", "a or B", "a or C", "B or C" or "A, B or C".

In this disclosure, the singular forms "a," "an," and "the" also include the corresponding plural referents, and reference to a particular value includes at least the particular value unless the context clearly dictates otherwise. Thus, for example, reference to "a substance" is a reference to at least one of such a substance and equivalents thereof.

Terms including ordinal numbers such as "first" and "second" may be used to explain various components or fluids, but the components, fluids are not limited by these terms. Accordingly, these terms are merely used to distinguish one component/fluid from another component/fluid without departing from the teachings of the present disclosure.

When items are described using the conjunctive terms "… … and/or … …," etc., the description should be understood to include any one of the associated listed items, as well as all combinations of one or more of the same.

In general, the use of the term "about" refers to an approximation that may vary depending on the desired properties obtained by the disclosed subject matter, and will be interpreted in a context-dependent manner based on the function. Thus, one of ordinary skill in the art will be able to interpret a degree of variability on an individual case basis. In some cases, the number of significant digits used in expressing a particular value can be a representative technique for determining the variance allowed by the term "about. In other cases, a gradient in a series of values may be used to determine the range of differences permitted by the term "about". Further, all ranges in this disclosure are inclusive and combinable, and reference to a value in a range includes each value in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs; the term and/or any and all combinations including one or more of the associated listed items.

The following examples were conducted under conventional conditions or conditions recommended by the manufacturer, without specifying the specific conditions. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

The present invention is further illustrated below with reference to specific examples, which are not intended to limit the invention in any way. Unless specifically stated otherwise, the reagents, methods and apparatus employed in the present invention are those conventional in the art. The essential features and significant effects of the invention can be seen from the following examples, which are described as some, but not all, of which, therefore, are not limiting of the invention, and some of the insubstantial modifications and adaptations of the invention by those skilled in the art are within the scope of the invention.

Example 1

Referring to fig. 1, the biological aerated filter of the invention comprises a tank body 1. The material and shape of the tank body 1 can be adjusted according to the nature of the wastewater to be treated, for example, the material can be plexiglass, and the shape can be hollow cylinder, square cylinder, and the like. The pool body 1 is provided with a liquid inlet and a liquid outlet, and the pool body 1 is sequentially provided with a water distribution area 17, a supporting layer 3, a packing layer 2 and a water outlet area 16 from top to bottom. The upper surface of the bearing layer 3 is connected with the lower surface of the packing layer 2 and is used for supporting the packing layer 2. The filler layer 2 is filled with volcanic rock and SENPs filler. The liquid inlet is arranged in the water distribution area 17, and the liquid outlet is arranged in the water outlet area 16. In addition, the volume ratio of the water distribution area 17, the supporting layer 3, the packing layer 2 and the water outlet area 16 is 20:5:30-50:25.

The filler layer 2 is filled with volcanic rock and SENPs filler. Wherein SENPs is provided by Nanjing Jiu Chuan environmental technology Co., ltd., particle size is 5-6 mm, bulk density is 1.2-1.3 g/cm ³, and porosity is 40-50%. In particular, reference may be made to the filler disclosed in chinese patent CN112723523 a. Volcanic rock is required to meet the requirements of 3-5 mm of particle size, 3.0-3.1 g/cm ³ of bulk density and 30-40% of porosity. In order to prevent the surface impurities of volcanic rock and SENPs from affecting the adhesion and adsorption properties of microorganisms on the surface thereof, it is necessary to wash and dry the surface before use. Washing with distilled water and ultrasonic treatment; drying to constant weight. As a specific embodiment, in the washing, the distilled water is washed 3 times, and the ultrasonic treatment is carried out for 30min at 25 ℃; in the drying, the temperature of the drying was 60 ℃. During operation, the packing in the packing layer 2 is subjected to membrane hanging, and the wastewater can be subjected to removal of nitrogen, phosphorus and COD _Mn and removal of antibiotics in the wastewater.

The supporting layer 3 is filled with filter materials, the particle size of the filter materials is 20-40 mm, solid suspended matters with larger particle size and the like in the wastewater can be primarily filtered while the filler layer 2 is supported, and the treatment of the filler layer 2 on the wastewater is facilitated. The filter material is one or two of gravel and cobble. In a preferred embodiment, the filter material filled in the supporting layer 3 is filled from the liquid inlet to the liquid outlet according to the particle size of the filter material from large to small, so that a better filtering effect can be obtained.

The water distribution area 17 is internally provided with aeration pipes 11 for aerating the tank body 1, and the number of the aeration pipes 11 can be one, two or more. As a specific implementation mode, the aeration pipe 11 in the water distribution area 17 is arranged perpendicular to the axis of the tank body 1 and is positioned above the liquid outlet. The aeration pipe 11 is provided with a plurality of microporous aeration filter heads to maintain the concentration of dissolved oxygen in water. As a specific embodiment, the liquid outlet is located below the aerator pipe 11.

On the other hand, the water distribution area 17 is provided with an air inlet, the air inlet is connected with the air inlet pipe 6 and is connected with the aeration pipe 11, the air inlet pipe 6 is sequentially provided with the air flow meter 8 and the air pump 7 from one end connected with the aeration pipe 11 to the other end, and the aeration intensity can be controlled through the air pump 7 and the air flow meter 8 so as to adjust the size and the quantity of bubbles generated by the microporous aeration filter head, thereby adjusting the dissolved oxygen, the pH value, the temperature and the like in the wastewater of the tank body 1 and meeting the optimal degradation condition of pollutants in the wastewater.

The liquid inlet is connected with a water inlet pipe 4, and the water inlet pipe 4 is connected with a water pump 5 to continuously convey the wastewater into the tank body 1. Specifically, the water pump 5 may be a peristaltic pump, a centrifugal pump, or the like, and different types of pumps may be selected according to processing requirements, or the like.

The water distribution area 17 is provided with a back flush water inlet and a back flush air inlet which are respectively connected with a back flush water inlet pipe 9 and a back flush air inlet pipe 10. The back flush inlet pipe 9 can be provided with a water pump 5 for conveying back flush liquid into the tank body 1, and the back flush inlet pipe 9 can be provided with a gas flowmeter 8 for conveniently controlling the flow of gas and the like. The aeration biological filter needs to be backwashed regularly, and can remove the retentate and the aged biological film on the supporting layer 3 and the packing layer 2 so as to restore the working capacity. The water body generated by back flushing can be discharged through the liquid outlet.

The liquid outlet is connected with a water outlet pool 20, a baffle 18 is arranged in the water outlet pool 20, the baffle 18 divides the water outlet pool 20 into a drainage area 12 and a back flushing drainage area 13, and the back flushing drainage area 13 is close to the pool body 1. The volume ratio of the water outlet area 16 to the water outlet pool 20 is 25:3-5. Further, the height of the top of the baffle 18 is higher than the height of the top of the liquid outlet. The drain region 12 is connected with a drain pipe 14, and treated wastewater is discharged to the outside or recovered through the drain pipe 14. The back flush drainage area 13 is connected with a back flush drainage pipe 15, and the water body generated by back flush is discharged to the outside or recovered through the back flush drainage pipe 15. Through the separation setting of drainage zone 12 and back flush drainage zone 13, can prevent effectively that the pollutant from entering into in the drainage zone 12 in the back flush drainage zone 13, lead to the waste water after handling to receive the pollution again, influence its recovery etc..

Further, the water outlet tank 20 is provided with a top plate 19, and the top of the baffle 18 is lower than the top plate 19, i.e. a gap is left between the baffle 18 and the top plate 19, so that the treated wastewater passes through the backwash water discharge area 13 and enters the water discharge area 12 from the gap.

The wastewater treatment method using the biological aerated filter in the embodiment specifically comprises the following steps: firstly, the biological aerated filter is subjected to membrane hanging, wherein the membrane hanging comprises volcanic rocks and SENPs fillers in a filler layer 2, and after the membrane hanging is successful, wastewater is treated.

The wastewater enters the tank body 1 of the biological aerated filter through the water inlet pipe 4, enters the water distribution area 17, is filtered by the supporting layer 3, is treated by the packing layer 2, can remove COD _Mn, ammonia nitrogen, TN, TP and antibiotics in the wastewater at the packing layer 2, and flows into the water drainage area 12 in the water outlet tank 20 through the liquid outlet of the water outlet area 16, and is discharged or recovered through the water drainage pipe 14. The volcanic rock filled by the filler layer 2 and SENPs filler have a volume ratio of 3:1-5:1, so that the nitrogen and phosphorus in the wastewater can be removed, and meanwhile, the antibiotics can be effectively removed. As a preferred embodiment, the volume ratio of the volcanic rock filled by the filler layer to SENPs filler is 3.5-4.5; even more preferably 4:1.

Considering the problems of effluent quality, biomembrane stability, energy saving, consumption reduction and the like, the air-water ratio during operation is 4:1-6:1, and the hydraulic load is 2-3 m ³/(m² & d). As a preferred embodiment, the gas-water ratio is 5:1, and the hydraulic load is 2.04m ³/(m². D). In addition, during operation, the aeration mode of the aeration pipe 11 in the water distribution area 17 is continuous aeration, and the dissolved oxygen range in water is kept to be 1.5 mg/L-2.0 mg/L.

After the wastewater treatment is finished, the operation of the aeration biological filter is stopped, and the aeration pipe 11 also stops aeration and back flushing. The back flushing is to simultaneously open a back flushing water inlet pipe 9 and a back flushing air inlet pipe 10, and a mode of combining air flushing and water flushing is adopted. The waste water generated by back flushing is discharged to the outside or recovered through the back flushing drainage area 13 and the back flushing drainage pipe 15.

The wastewater treated by the biological aerated filter is wastewater containing nitrogen, phosphorus and antibiotics, and is preferably aquaculture wastewater. Further, the biological aerated filter is used for removing antibiotics in aquaculture wastewater, wherein the antibiotics comprise fluoroquinolone antibiotics, sulfonamide antibiotics, chloramphenicol antibiotics and the like, for example, enrofloxacin, sulfamethoxazole and florfenicol which are typical antibiotics in aquaculture wastewater. Furthermore, the biological aerated filter can also remove COD _Mn, ammonia nitrogen, total nitrogen and total phosphorus in the aquaculture wastewater.

Example 2

In the embodiment, the biological aerated filter shown in figure 1 is adopted, wherein the tank body 1 is a cylinder and is made of organic glass, the height of the tank body is 600mm, and the diameter of the tank body is 70mm; the water distribution area 17, the supporting layer 3, the packing layer 2 and the water outlet area 16 are sequentially arranged from bottom to top, wherein the volume ratio of the water distribution area 17 to the supporting layer 3 to the packing layer 2 to the water outlet area 16 is 20:5:50:25, and the height of the packing layer is 300mm. The fillers in the filler zone are volcanic and SENPs fillers, and the volume ratio of volcanic to SENPs fillers is 4:1.SENPs filler is purchased from Nanjing Jihua Ind environmental technology research laboratory Co., ltd, is in a gray cylindrical shape, has a particle size of 5-6 mm, has a bulk density of 1.2-1.3 g/cm ³, and has a porosity of 40-50%; volcanic rock is purchased from Hebei Shuoding mineral product processing Co Ltd, and has the appearance of reddish brown irregular porous block filler, the particle size of 3-5 mm, the bulk density of 3.085g/cm ³ and the porosity of 30-40%. With reference to fig. 2, the outer surface of the volcanic rock is uneven and the specific surface area is large; SENPs the surface of the filler is rough and uneven, and certain cavities are distributed. The coarse morphology structure of volcanic rock and SENPs filler is convenient for microorganism adhesion and fixation and accelerates film formation; but also the abundant holes are beneficial to the internal mass transfer of the wastewater and promote the mass exchange of microorganisms. The volcanic rock and SENPs filler are washed 3 times with distilled water before use, sonicated for 30min at 25 ℃ to remove surface impurities, and oven dried to constant weight at 60 ℃. The volcanic rock and SENPs filler are ground, dried at 105 ℃ and screened by a 120-mesh sieve, and the undersize is taken for physical and chemical property detection, and the surface element composition is shown in table 1.

TABLE 1 volcanic and SENPs surface element compositions

As can be seen from table 1, the element composition of volcanic rock is mainly O, si, fe, al, ca, mg, etc.; the element composition of SENPs filler surface is mainly Fe, S and Si, etc., and forms the whole skeleton of filler, and small quantity of Mg, al, etc.

In the embodiment, a simulated aquaculture wastewater treatment experiment is carried out, wherein a certain amount of sodium acetate, ammonium chloride, monopotassium phosphate, potassium nitrate, sodium nitrite, urea, trace elements and the like are added into tap water to prepare a water sample with a certain concentration. The conventional water quality index is shown in Table 2.

TABLE 2 simulation of aquaculture wastewater quality

And adding a certain amount of enrofloxacin (Enrofloxacin, ENR), sulfamethoxazole (Sulfamethoxazole, SMX) and florfenicol (Florfenicol, FLO) into the simulated cultivation wastewater to make the concentration of the enrofloxacin (Enrofloxacin mug/L). It should be noted that, because the number of days of continuous water inflow is large, the prepared simulated aquaculture wastewater is easy to pollute after being placed for a long time, so that solutions are required to be prepared every day, certain errors exist in actual instrument detection, and the water inflow concentrations at different times are all in the normal fluctuation range.

The aeration biological filter is coated by adopting a sludge inoculation method, after the coating is successful, simulated aquaculture wastewater is used to pass through the aeration biological filter, the laboratory temperature is controlled between 25 ℃ and 28 ℃, the air-water ratio is 5:1, the hydraulic load is 2.04m ³/(m².d), the aeration mode of the aeration pipe 11 is continuous aeration, and the dissolved oxygen range in water is kept to be 1.5 mg/L-2.0 mg/L. The concentrations of COD _Mn、NH₃ -N, TN, TP and antibiotics in and out water are detected, and specific changes of water quality indexes and antibiotic concentrations are shown in figures 3 and 4. Wherein, the inoculated sludge in the sludge inoculation method is obtained from the biochemical pool sludge of the Nanjing Xianlin domestic sewage treatment plant.

According to the results shown in fig. 3 and 4, in the simulated cultivation wastewater treatment experiment for 21 days, the removal rate of COD _Mn by the aeration biological filter filled with volcanic rock and SENPs filler is stabilized to be about 60%, the removal rate of NH ₃ -N is stabilized to be more than 80%, the removal rate of TN is stabilized to be about 60%, the removal rate of TP is fluctuated to be about 70%, and the concentration of TP in effluent is lower than 0.3mg/L. When the water inlet concentration of the ENR, the SMX and the FLO is about 5 mug/L, the removal rate of the ENR, the SMX and the FLO by the BAF reactor is 98.7+/-0.7%, 56.7+/-6.0% and 21.0+/-3.9% respectively. The results show that the novel SENPs filler biological aerated filter has good removal effect on COD _Mn、NH₃ -N, TN and TP in the cultivation wastewater, and can also effectively reduce ENR and SMX in the wastewater, reduce the concentration of the ENR and SMX in the effluent, and realize synchronous removal of organic matters, nitrogen, phosphorus and antibiotics.

Moreover, volcanic rock surface is uneven and the specific surface area is large, SENPs filler surface is rough and uneven, and the volcanic rock filler has rich pore structures and provides a large number of adsorption sites. In addition, the ACE index (783), the Chao index (778) and the Shannon index (4.93) of the biological film formed in the filler area are all larger than the ACE index (749), the Chao index (747) and the Shannon index (4.30) of the biological film on the surface of the volcanic filler, which indicate that the biological film has relatively higher richness and microorganism diversity, and the increase of the filler type can increase the diversity of microorganisms in a system to a certain extent. Chloroflexi (Apolybdenum) is detected in a biological film on the surface of SENPs filler, the ratio is 12.8%, chloroflexi is a facultative anaerobic microorganism, and the biological film has the functions of nitrification, denitrification and dephosphorization, and the detection of the facultative anaerobic microorganism in the biological film indicates that an anaerobic/aerobic microenvironment is formed in the filler biological film, thereby being beneficial to further improving the biodegradation efficiency of antibiotics. Further, the applicant has found from previous experimental studies that SENPs alone was not found Chloroflexi when used as a filler film. In particular, reference may be made to literature 1(Liang Y,Wei D,Hu J,et al.Glyphosate and nutrients removal from simulated agricultural runoff in a pilot pyrrhotite constructed wetland.Water Research,2020,168(Jan.1):115154.1-115154.7.DOI:10.1016/j.watres.2019.115154.) and literature 2(A,Ying Liang,et al.Performance of a novel magnetic solid-phase-extraction microsphere and its application in the detection of organic micropollutants in the Huai River,China.Environmental Pollution,252(2019):196-204.). and ENR has a relatively high hydrophilicity, is prone to photolysis and is prone to adsorption. Therefore, after the wastewater containing antibiotics enters the reactor, the stuffing and the biomembrane attached to the surface thereof adsorb the ENR, and meanwhile, the metabolism degradation effect of microorganisms and the co-metabolism effect of the nitration process are also beneficial to the degradation of part of the ENR, so that the ENR is efficiently reduced, and the removal rate of the ENR is higher and reaches 98.7+/-0.7 percent.

Claims

1. The utility model provides a biological aerated filter which characterized in that: comprises a tank body, a water tank and a water tank,

The tank body is provided with a liquid inlet and a liquid outlet,

The packing layer is filled with volcanic rock and SENPs packing.

2. A biological aerated filter according to claim 1 wherein:

The volume ratio of the water distribution area to the supporting layer to the packing layer to the water outlet area is 20:5:30-50:25.

3. A biological aerated filter according to claim 1 or claim 2 wherein:

The supporting layer is filled with filter materials, and the particle size of the filter materials is 20-40 mm.

4. A biological aerated filter according to claim 3 wherein:

The liquid outlet is connected with a water outlet tank, and a baffle is arranged in the water outlet tank;

The baffle divides the water outlet pool into a drainage area and a back flushing drainage area, and the back flushing drainage area is arranged close to the pool body.

5. A method for treating wastewater containing nitrogen and phosphorus and antibiotics by using the biological aerated filter according to any one of claims 1 to 4, comprising the steps of:

6. The method for treating wastewater containing nitrogen and phosphorus and antibiotics according to claim 5, wherein the method comprises the following steps:

The volume ratio of volcanic rock filled by the packing layer to SENPs packing is 3.5:1-4.5:1.

7. The method for treating wastewater containing nitrogen and phosphorus and antibiotics according to claim 5 or 6, wherein the method comprises the following steps:

The air-water ratio during operation is 4:1-6:1, and the hydraulic load is 2-3 m ³/(m². D).

8. The method for treating wastewater containing nitrogen and phosphorus and antibiotics according to claim 7, wherein:

Also comprises an aeration pipe for aeration,

9. The method for treating wastewater containing nitrogen and phosphorus and antibiotics according to claim 8, wherein the method comprises the following steps:

the grain diameter of SENPs-6 mm, the bulk density of 1.2-1.3 g/cm ³ and the porosity of 40-50%;

The grain diameter of the volcanic rock is 3-5 mm, the stacking density is 3.0-3.1 g/cm ³, and the porosity is 30-40%.

10. The method for treating wastewater containing nitrogen and phosphorus and antibiotics according to claim 9, wherein the method comprises the following steps:

the antibiotics are one, two or more than two of fluoroquinolone antibiotics, sulfonamide antibiotics or chloramphenicol antibiotics.