Identification and Screening Method and Application of Chaotic Samples Based on Determination of Filter Medium Service Life

Abstract

The present invention relates to a method for identifying and screening chaotic samples based on the determination of the service life of filter media and its application, and relates to the technical field of water treatment. The method for identifying and screening chaotic samples based on the determination of the service life of filter media includes the following steps: (1) treatment of the samples to be inspected; (2) inspection of the samples to be inspected. The present invention can quickly identify and screen the samples to be inspected among 1 to 4 billion ordinary filter media in a large denitrifying biological filter through strong magnetic attraction, and / or colored resin, and / or particle size; the present invention takes into account the biochemical consumption, which is one of the important indicators for evaluating the service life of pyrite filter media, and at the same time, the detection of wear value and breakage value is more accurate than the method recommended by the water treatment filter media standard (CJ / T 43-2005) under the same operating environment.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and particularly to a method for identifying and screening chaotic samples based on the determination of the service life of filter media and its application. Background Art

[0002] During the evaluation of the durability and service life of filter media in a filter tank, the wear rate and breakage rate of the filter media are important indicators of the performance of the filter media. Among them, the wear rate refers to the proportion of the filter media that flakes or breaks due to friction and wear during backwashing and filtration processes, and the breakage rate refers to the proportion of the filter media that is damaged due to the action of external forces or the force of the filtration medium during use. When the wear rate and breakage rate of the filter media are too large, it will lead to a deterioration of the filtration effect, a slowdown of the filtration speed, and a shortening of the service life of the filter media. In the water treatment filter media standard (CJ / T 43-2005), the sum of the wear rate and breakage rate of quartz sand filter media should not be greater than 1.5% (by mass).

[0003] Pyrite particle filter media has a Mohs hardness of 6.0 - 6.5; the patent with the publication number CN117430296 shows that it has good wear resistance, and thus has a filtration performance similar to quartz sand for intercepting SS suspended solids. Intermittent air-water backwashing will cause wear and breakage of pyrite particle filter media. At the same time, since pyrite-mediated autotrophic denitrification achieves the synchronous removal of nitrogen and phosphorus through the synergistic action of the dual pathways of "biologically driven denitrification - abiotic chemical phosphorus removal"; therefore, pyrite particle filter media will have a certain biochemical consumption, and biochemical consumption is one of the important indicators for evaluating the service life of pyrite filter media in addition to the wear rate and breakage rate. So far, the water treatment filter media standard (CJ / T 43-2005) only describes the determination methods for the wear rate and breakage rate of filter media, and no relevant literature has comprehensively and systematically regulated and elaborated on the determination of the biochemical consumption rate for the service life of pyrite filter media.

[0004] In addition, the following problems exist in the process of evaluating the durability and service life of filter media in a filter: (1) The measurement methods for the wear rate and breakage rate of filter media in the water treatment filter media standard (CJ / T 43-2005) belong to dry simulation, which has great limitations and fails to truly represent the actual state of the filter media during processes such as filtration, air-water backwashing, and static settlement. Therefore, the error in the estimated service life is relatively large. (2) During the determination of the randomly selected samples of filter media in the filter, due to the large area of the filter, there are approximately 10 million equal-round particles with a particle size of 2-3 mm per cubic meter of filter media. When air-water combined backwashing is adopted, as long as the washing water flow rate reaches 40-50% of the minimum fluidization washing flow rate, strong agitation and circulation effects will be generated in the filter bed. At the beginning of the washing, the entire filter bed will be disturbed. In the air flow vortex area formed when the bubbles rise, the rolling of the filter media will cause intense collision and friction between the filter media particles. At this time, about 30-10 billion filter media particles in the filter are in a chaotic state, and the movement trajectories of the randomly selected samples of filter media are difficult to trace and identify. In addition, when the outlet weir of the filter is too low, sand running of the filter media will occur, and further, the detection data of the total mass loss of the filter media cannot maintain continuity and scientificity. In view of the above problems, the present invention provides a method for identifying and screening chaotic samples based on the determination of the service life of filter media and its application. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for identifying and screening chaotic samples based on the determination of the service life of filter media and its application. The purpose is to achieve the rapid identification and screening of randomly selected samples of filter media particles in a chaotic motion state in a denitrifying biological filter, weigh the randomly selected samples of filter media at fixed intervals during operation, and fit the change curve of the mass loss of the randomly selected samples of filter media by systematic random sampling, so as to accurately determine the service life of the filter media.

[0006] The technical solution of the present invention for solving the above technical problems is as follows:

[0007] In the first aspect, a method for identifying and screening chaotic samples based on the determination of the service life of filter media includes the following steps:

[0008] (1) Treatment of the randomly selected samples to be inspected:

[0009] Obtain the maximum particle size of the filter media to be inspected ; make the particle size of the randomly selected samples to be treated be the maximum particle size of the filter media to be inspected 1.0 to 1.1 times; perform drilling treatment on the randomly inspected sample to be processed to obtain a drilled randomly inspected sample, and the drilled randomly inspected sample has the same reaction specific surface area as the filter media to be inspected; insert a magnetic metal segment into the inner pore of the drilled randomly inspected sample, and seal and cover both ends of the pore of the drilled randomly inspected sample with a colored resin to obtain a marked randomly inspected sample; take the lowest weight of a single marked randomly inspected sample as the reference weight, and make the weights of all the marked randomly inspected samples equal to the reference weight to obtain the randomly inspected samples to be inspected.

[0010] (2)Random inspection of randomly inspected samples:

[0011] Put the randomly inspected samples to be inspected into the filter tank, and make the randomly inspected samples to be inspected and the filter media to be inspected operate in the same environment; according to the sampling period, randomly inspect the randomly inspected samples to be inspected at the peak of the air-water backwashing intensity when the filter layer particles are in an expanded and suspended state by means of strong magnetic attraction, or / and colored resin, or / and particle size to obtain randomly inspected samples.

[0012] Among them, the present invention strictly limits the fixed multiple relationship between the diameters of the drilled randomly inspected sample and the filter media to be inspected through the composite volume derivation formula to ensure that the two have the same reaction specific surface area.

[0013] The beneficial effects of the present invention are:

[0014] (1)The method for identifying and screening chaotic samples based on the service life determination of filter media of the present invention can quickly identify and screen randomly inspected samples among 1 to 4 billion ordinary filter media in a large-scale denitrifying biological filter tank by means of strong magnetic attraction, or / and colored resin, or / and particle size.

[0015] (2)When the present invention uses pyrite filter media as the filter media to be inspected, one of the important indicators for evaluating the service life, namely biochemical consumption, is considered. At the same time, the same operating environment makes the detection of wear value and breakage value more accurate than the method recommended by the filter media standard for water treatment (CJ / T 43-2005).

[0016] (3)During the later operation, the density difference and area difference between the randomly inspected samples and ordinary particles are small, and large-scale layer running will not occur. The probability that all randomly inspected samples are distributed in the aerobic zone and the anaerobic zone follows a normal distribution. Therefore, it is not necessary to collect randomly inspected samples by stratification, reducing the sampling difficulty.

[0017] (4)The method for identifying and screening chaotic samples based on the service life determination of filter media of the present invention has a unified initial weight for the randomly inspected samples of filter media, which is convenient for later statistical induction. The random sampling method adopted ensures the scientific nature of the data.

[0018] On the basis of the above technical solutions, the present invention can also be improved as follows.

[0019] Further, the treatment of the sampling samples to be inspected in step (1) includes the following specific steps:

[0020] (1-1) Collect the particle size range of the filter media to be inspected, and obtain the maximum particle size of the filter media to be inspected; make the particle size of the sampling sample to be treated be 1.0 - 1.1 times the maximum particle size of the filter media to be inspected; according to the particle size of the sampling sample to be treated obtain the drilling diameter of the sampling sample to be treated; (1-2) According to the drilling diameter of the sampling sample to be treated, perform drilling treatment on the sampling sample to be treated to obtain a drilled sampling sample, and the drilled sampling sample has the same reactive specific surface area as the filter media to be inspected; insert a magnetic metal segment into the inner part of the pore channel of the drilled sampling sample, and seal and cover both ends of the pore channel of the drilled sampling sample with a colored resin to obtain a marked sampling sample; (1-3) Weigh the marked sampling samples uniformly, take the minimum weight of a single marked sampling sample as the reference weight, and grind the marked sampling samples with a weight exceeding the reference weight using a grinding wheel so that the weights of all the marked sampling samples are equal to the reference weight to obtain the sampling samples to be inspected.

[0021] The beneficial effect of adopting the above further solution is that by enhancing the magnetism of the sampling samples, or / and using a colored resin to identify the samples, or / and appropriately increasing the particle size of the sampling samples, etc., at least one of these measures can quickly collect the sampling samples in the chaotic state after intense movements such as air-water backwashing;

[0022] And establish the reference weight of the sampling samples, and its initial weight is a unified weight, which is convenient for later statistical induction and ensures the scientific nature of the continuous random sampling data.

[0023] Further, the specific method for obtaining the drilling diameter of the sampling sample to be treated in step (1-1) is as follows: Calculate the drilling diameter of the sampling sample to be treated through the following formula (1); formula (1) is as follows:

[0024]

[0025]

[0026]

[0027] (1);

[0027] In formula (1), is the particle size of the sampling sample to be treated, is the drilling diameter of the sampling sample to be treated, and the value range of N is 1.0 - 1.1.

[0028] The beneficial effects of adopting the above further solution are as follows: The particle size of the randomly sampled filter media is larger than that of ordinary filter media particles, but does not exceed 10% of the maximum particle size of ordinary filter media, preventing the particle size difference of the later sampled samples from being too large and avoiding stratification during the air-water backwashing process due to different water-facing areas of the particles.

[0029] Further, the magnetic metal segment in step (1-2) includes one or at least two alloys of iron, nickel, and cobalt; the diameter of the magnetic metal segment is not greater than the drilling diameter of the sampled sample to be processed, and the length of the magnetic metal segment is less than the drilling length of the sampled sample to be processed; furthermore, the length of the magnetic metal segment is about half of the drilling length of the sampled sample to be processed.

[0030] The colored resin in step (1-2) includes at least one of colored epoxy resin, alkyd resin, phenolic acid resin, and polyurethane resin, and the dosage of the colored resin is half of the drilling length.

[0031] The beneficial effects of adopting the above further solution are as follows: The average density of the magnetic metal segment and the colored resin is approximately equal to the density of pyrite particles, controlling the density difference between the sampled sample and the ordinary standby filter media to be less than 5%, and avoiding the running layer of the sampled sample due to the huge density difference of the particles during the later operation. Therefore, there is no need to collect the sampled samples in layers, greatly reducing the sampling difficulty.

[0032] Further, the sampling of the sampled sample in step (2) includes the following specific steps:

[0033] (2-1) Put the sampled sample to be inspected into a specific range of the filter layer of the filter tank, so that the sampled sample to be inspected and the standby filter media operate in the same environment.

[0034] (2-2) According to the sampling period, randomly extract the sampled sample to be inspected within the specific range through strong magnetic attraction, or / and colored resin, or / and particle size when the filter layer particles are in an expanded and suspended state at the peak of the air-water backwashing intensity to obtain the sampled sample.

[0035] The beneficial effects of adopting the above further solution are as follows: The same operating environment makes the detection of wear value and breakage value more accurate than the method recommended by the standard for filter media for water treatment (CJ / T 43-2005); when pyrite filter media is used as the standby filter media, the biochemical consumption, which is one of the important indicators for evaluating the filter media usage period, is fully considered.

[0036] Further, the specific range of the filter layer of the filter tank in step (2-1) is obtained through a perforated baffle; the side length of the perforated baffle is 1.2 m to 2 m, and the height of the perforated baffle exceeds the water overflow of the filter tank by more than 20 cm.

[0037] The beneficial effects of adopting the above further solution are as follows: By using the perforated baffle to reduce the movement area and narrow the sampling range, the number of ordinary filter materials in the large-scale denitrifying biological filter is reduced from 3 to 10 billion to 30 million.

[0038] Further, in step (2-2), the sampling period interval is at least 10 days, and at least 50 consecutive cycles are taken to ensure the representativeness of the sample data.

[0039] The beneficial effects of adopting the above further solution are as follows: This sampling method has extremely strong randomness, can break through the subjective and fixed limitations, randomly and evenly select samples from numerous samples of the filter, and has a wide coverage, greatly increasing the probability of obtaining diverse samples.

[0040] In the second aspect, an application of the sampled samples randomly inspected by the method for identifying and screening chaotic samples based on the service life determination of filter materials in the construction of a service life determination model for the filter materials to be inspected.

[0041] The beneficial effects of adopting the above solution are as follows: By constructing the model of the present invention, the biochemical consumption, which is one of the important indicators for evaluating the service life of pyrite filter materials, is considered. At the same time, under the same operating environment, the detection of wear value and breakage value is more accurate than the method recommended by the filter material standard for water treatment (CJ / T 43-2005).

[0042] In the third aspect, a method for constructing a model for determining the service life of filter materials includes the following steps: Recording the quality data of each sampling cycle of the sampled samples randomly inspected by the method for identifying and screening chaotic samples based on the service life determination of filter materials, and fitting a quality loss curve; According to the fitted quality loss curve, determine the service life of the filter materials to be inspected.

[0043] Further, when the filter materials to be inspected are pyrite filter materials, the equation of the quality loss curve is as shown in formula (2):

[0044] (2);

[0045] In formula (2), x is the service life of the filter materials; y is the mass of pyrite filter materials corresponding to a certain cycle;

[0046] When the filter materials to be inspected are quartz sand filter materials, the equation of the quality loss curve is as shown in formula (3):

[0047] (3);

[0048] In formula (3), x is the service life of the filter materials; y is the mass of quartz sand filter materials corresponding to a certain cycle.

[0049] The beneficial effects of adopting the above further solution are as follows: The linear equation fitted by the model construction method of the present invention can be used to scientifically show the quality loss change of the sampled products and predict the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a schematic structural layout diagram of the filter layer, supporting layer and filter floor in the filter of the present invention.

[0051] Figure 2 It is a schematic layout diagram of the perforated stainless steel enclosing plate in the filter of the present invention.

[0052] Figure 3 It is a schematic connection diagram of the upper and lower perforated stainless steel enclosing plates of the present invention.

[0053] Figure 4 It is an assembly drawing of the perforated stainless steel enclosing plate in the filter and the filter of the present invention.

[0054] Figure 5 It is a comparison diagram of the particle sizes of the ordinary filter material and the sampled products of the present invention.

[0055] Figure 6 It is a comparison diagram of the wear and breakage prediction curve and biochemical consumption prediction curve of the sampled products of the present invention.

[0056] Figure 7 It is a comparison diagram of the wear and breakage curves of the sampled products of the present invention.

[0057] Figure 8 It is a wear and breakage curve diagram of the quartz sand sampled product of the present invention.

[0058] Figure 9 It is a wear and breakage prediction curve diagram of the quartz sand sampled product of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0059] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention. For those not specifying specific techniques or conditions in the examples, the techniques or conditions described in the literature in this field or according to the product specifications are followed. For those reagents or instruments not specifying the manufacturer, they are all conventional products that can be purchased through regular channels.

[0060] This embodiment relates to a method for identifying and screening chaotic samples based on the determination of the service life of filter materials, including the following steps:

[0061] (1) Treatment of the sampled products to be inspected:

[0062] Obtain the maximum particle size of the filter material to be inspected ; make the particle size of the sampled products to be treated be the maximum particle size of the filter material to be inspected 1.0 to 1.1 times; perform drilling on the randomly inspected sample to be processed to obtain a drilled randomly inspected sample, and the drilled randomly inspected sample has the same reactive specific surface area as the reference filter material; insert a magnetic metal segment into the inner pore of the drilled randomly inspected sample, and seal and cover both ends of the pore of the drilled randomly inspected sample with a colored resin to obtain a marked randomly inspected sample; take the minimum weight of a single marked randomly inspected sample as the reference weight, and make the weights of all the marked randomly inspected samples equal to the reference weight to obtain the randomly inspected samples to be inspected.

[0063] Preferably in this embodiment, the processing of the randomly inspected samples to be inspected in step (1) includes the following specific steps:

[0064] (1-1) Collect the particle size range of the reference filter material to obtain the maximum particle size of the reference filter material ; make the particle size of the randomly inspected sample to be processed be 1.0 to 1.1 times the maximum particle size of the reference filter material ; according to the particle size of the randomly inspected sample to be processed , obtain the drilling diameter of the randomly inspected sample to be processed.

[0065] (1-2) According to the drilling diameter of the randomly inspected sample to be processed, perform drilling on the randomly inspected sample to be processed to obtain a drilled randomly inspected sample, and the drilled randomly inspected sample has the same reactive specific surface area as the reference filter material; insert a magnetic metal segment into the inner pore of the drilled randomly inspected sample, and seal and cover both ends of the pore of the drilled randomly inspected sample with a colored resin to obtain a marked randomly inspected sample;

[0066] (1-3) Weigh the marked randomly inspected samples uniformly, take the minimum weight of a single marked randomly inspected sample as the reference weight, and grind the marked randomly inspected samples that exceed the reference weight, for example, using a grinding wheel, to make the weights of all the marked randomly inspected samples equal to the reference weight to obtain the randomly inspected samples to be inspected.

[0067] Specifically in this embodiment, the specific method for obtaining the drilling diameter of the randomly inspected sample to be processed in step (1-1) is as follows: Calculate the drilling diameter of the randomly inspected sample to be processed through the following formula (1); formula (1) is as follows:

[0068] (1); in formula (1) is the particle size of the randomly inspected sample to be processed, is the drilling diameter of the randomly inspected sample to be processed, and the value range of N is 1.0 to 1.1, such as 1.01, 1.03, 1.06, 1.07, 1.08, 1.1, etc.

[0069] Specifically in this embodiment, the magnetic metal segment in step (1-2) includes an alloy of one or at least two of iron, nickel, and cobalt; the diameter of the magnetic metal segment is not greater than the drilling diameter of the sampled inspection sample to be processed, and the length of the magnetic metal segment is less than the drilling length of the sampled inspection sample to be processed; specifically, the length of the magnetic metal segment is half of the drilling length of the sampled inspection sample to be processed.

[0070] The colored resin in step (1-2) includes at least one of colored epoxy resin, alkyd resin, phenolic acid resin, and polyurethane resin; specifically, the colored resin is half of the drilling length.

[0071] To identify and screen the sampled inspection samples of filter media particles in the denitrifying biological filter under chaotic motion, the sampled inspection samples were drilled, a magnetic metal segment, such as an iron wire segment, was inserted into the inner part of the hole, and both ends of the hole were sealed and covered with a colored resin (such as a red aerobic resin seal). During the later sampling process, a simple tool such as a strong magnet bar was inserted into the filter media particle layer during the air-water backwashing process to carry out the sampled inspection samples. In the static state, the samples could be quickly collected through the color marking of the colored resin. Among them, the dosages of the magnetic metal segment and the epoxy resin can be set in different volumes according to the density of the heavy density ore filter media (pyrite filter media), so that the average density of the magnetic metal segment and the epoxy resin is close to that of the heavy density ore filter media, preventing the sampled inspection samples from running out of layers due to the huge difference in particle density.

[0072] Although the magnetic recognition can be increased by setting a magnetic metal segment inside the sampled inspection sample, and the image recognition can be increased by covering the outer surface with colored epoxy resin, the colored epoxy resin covering part on the outer surface of the sampled inspection sample does not produce biochemical consumption. In order to avoid significant differences in the biochemical consumption rates between the filter media with the same particle size and equal surface area and the sampled inspection samples. The present invention increases the particle size of the sampled inspection samples so that the surface area of the pyrite that produces biochemical consumption (excluding the part covered by the colored epoxy resin) is basically equal to that of the filter media in the filter tank, and increasing the particle size of the sampled inspection samples also further increases the mesh recognition degree of the sampled inspection samples.

[0073] As Figure 5 shown, the specific surface area of the initial filter media sphere to be inspected is , and the diameter is . Let the specific surface area of the filter media sampled inspection sample sphere be , and the diameter be ; the diameter of the marked hole of the sampled inspection sample sphere is , and the specific surface area of the spherical crowns on both sides of the marked hole is ; when the specific surface area of the sampled inspection sample after deducting the hole crowns ( - ) is the same as the specific surface area of the pyrite filter media sphere When the values ​​are equal, the maximum particle size of the filter media is Particle size of sample And the diameter of the ball marking hole The relationship is as follows:

[0074] (4);

[0075] Particle size of general sampling samples The maximum particle size of the filter media 1.0~1.1 times of the diameter of the sample sphere With marked hole diameter The relationship is as follows:

[0076] (1);

[0077] In addition, all samples randomly inspected are weighed uniformly, and the lowest weight of a single particle is selected as the basis. Other overweight particles are ground with a grinding wheel to ensure that all samples randomly inspected maintain a uniform weight.

[0078] (2) Random inspection of samples:

[0079] The sample to be sampled is placed in the filter tank ( Figure 1 ), so that the sample to be inspected and the filter material to be inspected are operated in the same environment; according to the sampling cycle, through strong magnetic attraction, and / or colored resin, and / or particle size, at the peak of the air-water backwashing intensity, the filter layer particles are in an expanded and suspended state, and the sample to be inspected is randomly inspected to obtain the sample.

[0080] In this embodiment, the sampling of samples in step (2) preferably includes the following specific steps:

[0081] (2-1) When the denitrification biofilter is backwashing, the sample to be sampled is placed within a specific range of a certain filter layer at a certain height of the filter. Figure 4 ), so that the sample to be inspected and the filter material to be inspected are operated in the same environment;

[0082] (2-2) According to the sampling period, the sample to be inspected is randomly sampled within the specific range by strong magnetic attraction, or / and colored resin, or / and particle size to obtain the sample.

[0083] Preferably, in the present embodiment, the specific range of the filter layer of the filter tank in step (2-1) is obtained by a perforated enclosure; the side length of the perforated enclosure is 1.2m~2m, and the height of the perforated enclosure exceeds the filter tank flooding by more than 20 cm.

[0084] To ensure that the sampled products operate in the same environment as the ordinary particles of the filter media, specifically, in the area about 50 cm close to the side wall of the denitrifying biological filter, a perforated 304 stainless steel plate enclosure is used to define an arbitrary area of 2 m × 2 m. The gas-water backwashing arranged at the bottom of the area causes basically the same degree of collision and wear to the filter media particles. The micropores ensure the continuous circulation of sewage inside and outside the enclosure, exert a biochemical effect on the particles, and prevent the sampled products of the filter media from leaking out of the enclosure.

[0085] Among them, the perforated 304 stainless steel plate enclosure is divided into a perforated upper enclosure and a perforated lower enclosure. The upper enclosure and the lower enclosure are butt-jointed by a flange 30 cm above the surface of the filter media layer, and the bottom of the lower enclosure is fixed to the filter tank bottom plate by bolts. The top of the upper enclosure is 20 cm higher than the overflow water ( Figure 2 and 3 ).

[0086] Specifically in this embodiment, the sampling period interval in step (2-2) is at least 10 days, and at least 50 cycles are sampled continuously. For example, the sampling period interval is 15 days, and 50 cycles are sampled continuously, etc.;

[0087] This embodiment also relates to using the sampled products randomly inspected by the identification and screening method of chaotic samples based on the service life of the filter media in the model construction for determining the service life of the filter media to be inspected.

[0088] This embodiment also relates to a method for constructing a model for determining the service life of filter media, including the following steps: recording the quality data of each sampling cycle of the sampled products, fitting a mass loss curve according to the quality change; and determining and predicting the service life of the filter media to be inspected according to the fitted mass loss curve.

[0089] Specifically in this embodiment, after unifying the weights of all sampled products, a certain number of filter media particles are randomly sampled from the filter tank at a fixed cycle (T = 10 days) as samples, and 50 cycles are sampled continuously. Record the quality data of the sampled products in each cycle. To scientifically reflect the trend and law of the mass loss of the filter media, a linear function relationship between the quality of the sampled products and the sampling cycle T is constructed as follows:

[0090] (5);

[0091] Among them, in formula (5), M sam is the quality of the sampled products, K is the change rate of the wear and breakage curve, T is the reaction cycle of the sampled products, and b is the initial maximum mass value of the sampled products.

[0092] When the filter media to be inspected is pyrite filter media, the obtained mass loss curve equation is as shown in formula (2):

[0093] (2);

[0094] In formula (2), x is the service life cycle of the filter media; y is the mass of pyrite filter media corresponding to a certain cycle.

[0095] When the filter media for inspection is quartz sand filter media, the equation of the mass loss curve of the obtained quartz sand filter media is as shown in formula (3):

[0096] (3);

[0097] In formula (3), x is the service life cycle of the filter media; y is the mass of quartz sand filter media corresponding to a certain cycle.

[0098] In summary, the method for identifying and screening chaotic samples based on the service life cycle determination of filter media according to the present invention can quickly identify and screen the sampled samples in a large-scale denitrifying biological filter (1 to 4 billion ordinary filter media) through strong magnetic attraction, or / and colored resin, or / and particle size.

[0099] For the method for identifying and screening chaotic samples based on the service life cycle determination of filter media according to the present invention, the density difference between the sampled samples and the ordinary filter media for inspection is less than 5%. During the later operation, due to the huge difference in particle density, the sampled samples will not run out of layers, so there is no need to collect the sampled samples in layers, greatly reducing the sampling difficulty.

[0100] For the method for identifying and screening chaotic samples based on the service life cycle determination of filter media according to the present invention, the initial weights of the sampled samples are unified, which is convenient for later statistical induction. The random sampling method adopted ensures the scientificity and universality of the data.

[0101] When constructing the model according to the present invention, the biochemical consumption, which is one of the important indicators for evaluating the service life cycle of pyrite filter media, is considered. At the same time, the operating environment makes the detection of wear value and breakage value more accurate than the method recommended by the filter media standard for water treatment (CJ / T 43-2005). The following is illustrated with specific examples.

[0102] Example 1: Determination of the particle size of the sampled samples and the diameter of the marked holes of the filter media with a particle size of 2 - 3 mm.

[0103] Let the maximum particle size specific surface area of pyrite filter media with a particle size range of 2 - 3 mm be , and the maximum particle size be ; the specific surface area of the spherical sampled sample is , and the diameter is ; the diameter of the marked hole of the spherical sampled sample is , and the specific surface area of the spherical crown on both sides of the marked hole is . When the specific surface area of the sampled sample after deducting the hole crown ( - ) is the same as the maximum particle size specific surface area of the pyrite filter media sphere When they are equal, the maximum particle size of the ordinary filter material in the filter tank is and the particle size of the sampled product and the diameter of the marked hole of the sphere The relational formula is shown in formula (4) and can be deduced according to the following relational formula.

[0104] The specific surface area of the sampled product after deducting the hole crown and the specific surface area of the pyrite filter material sphere satisfy the following relational formula (6):

[0105] (6);

[0106] Based on the specific surface area formula of the sphere and the spherical crown area formula, the calculation formulas for the specific surface area of the sampled product, the initial pyrite filter material sphere, and the spherical crown on both sides of the marked hole are determined and substituted into formula (6) to obtain formula (7):

[0107] (7);

[0108] Eliminate the like terms on both sides of formula (7) and remove the denominator of the formula to obtain formula (8):

[0109] (8);

[0110] Move the terms of formula (8). To more intuitively show and , The quantitative relationship between them, finally formula (4) can be obtained.

[0111] Generally, the particle size of the sampled product is N (1.0 - 1.1) times the average particle size of the filter material in the filter tank, that is The relational formula between

[0112] (9);

[0113] Substitute formula (9) into formula (4) to obtain The relational formula (1) between and

[0114] The derivation process is as follows: After substituting various numerical values and simplifying, formula (10) can be obtained:

[0115] (10);

[0116] Remove the square root of formula (10) and raise the order of the unknown on both sides to obtain formula (11):

[0117] (11);

[0118] Removing the denominator and transposing Equation (11) gives Equation (12):

[0119] (12);

[0120] Combining like terms in Equation (12) gives Equation (13):

[0121] (13);

[0122] Transposing Equation (13) intuitively shows the relationship between and and defines the multiple relationship of the N value, and finally Equation (1) can be obtained. and and finally obtains Equation (1).

[0123] In this embodiment, the initial diameter of the pyrite filter media sphere is 3.00 mm, then the diameters of the sampled spheres are distributed as shown in Table 1. During the test process, specific values of a certain multiple relationship are selected, and a spherical drill is used to perform precise marking hole operations on the initial pyrite spheres. At this time, a hollow groove structure can be generated inside the sampled spheres. The surface area composite derivation diameter relationship formula (1) is used to calculate the marking hole diameter, and the relevant data are recorded as shown in Table 1,[[]] and the corresponding value is the precise diameter of the marking hole of the sampled sphere under this multiple relationship.

[0124] Table 1 Diameter multiple relationship of filter media spheres under different multiple relationships

[0125]

[0126] Example 2: Determination of the service life of pyrite sampled samples.

[0127] In this embodiment, a downward-flow denitrifying biological filter is used, with pyrite as the filter media. The influent COD concentration is 50.1 mg / L, pH < 7, the effluent total nitrogen < 10 mg / L, the air washing time is 5 min, the intensity ≤ 27.78 L / (m 2 ·s), the water washing time is 10 min, the intensity ≤ 4.17 L / (m 2 ·s), the air-water combined washing time is 8 min, the intensity ≤ 15.5 L / (m 2 ·s), and the effluent filtration rate is 6 m / h.

[0128] (1) Data preparation and collection:

[0129] Step ①: To make all sampled samples maintain a unified weight, the standard mass is calculated using Equation (14). According to the physical and chemical properties of pyrite,[[]] the density of pyrite usually takes 5.0 g / m the density of pyrite usually takes 5.0 g / m3 , so the initial sample mass is calculated to be 0.75g.

[0130] (14);

[0131] (15);

[0132] Step ②: According to the above sampling method, a certain number of filter particles are extracted from the filter tank as samples at a fixed period (T=10 days) for 50 consecutive cycles.

[0133] Step ③: Record relevant data such as the quality of the extracted samples.

[0134] (2) Data analysis:

[0135] Step ①: Conduct statistical analysis on the collected quality data and eliminate the samples with large deviation values.

[0136] Step ②: Analyze the relationship between sample quality and sampling period to understand the trend and law of filter material quality loss.

[0137] (3) Establish a prediction model:

[0138] Build sample quality , the linear function relationship of the sampling period T, is initially proposed as the following one-variable linear equation (5):

[0139] (5);

[0140] Based on the actual operation of the filter, in this equation As the period T increases, regular changes should gradually occur, showing a monotonically decreasing trend. According to the sampled samples, a linear equation group between the quality change and the filter material use period can be fitted, and the model fitting degree R can be calculated. 2 , if R 2 >0.7, indicating a higher linear fitting effect, indicating that the equation can be used to show the changing law of sample mass loss.

[0141] When pyrite is used as an electron donor, according to the total denitrification reaction equation of pyrite (16):

[0142] (16);

[0143] When the filter water flow rate =6m / h, when the initial nitrate nitrogen concentration is 10mg / L, the theoretical consumption of NO in one year 3 - The quality of is as shown in formula (17):

[0144] (17);

[0145] According to Equation (16), FeS can be obtained 2 \NO 3 The ratio relationship between them can be determined, and then the mass of FeS consumed theoretically in one year can be determined 2 as shown in Equation (18):

[0146] (18);

[0147] The total mass of FeS existing in the theoretical filter tank is as shown in Equation (19): 2 as shown in Equation (19):

[0148] (19);

[0149] Then, theoretically, the time required for the complete consumption of FeS 2 is as shown in Equation (20):

[0150] (20);

[0151] Then, according to the theoretical consumption period of the filter material (calculated as 27 years), the theoretical prediction line of the mass loss value can be deduced, as shown in Equation (21):

[0152] (21);

[0153] Substituting the values, Equation (22) can be obtained, and the goodness of fit R 2 = 1.0000

[0154] (22);

[0155] According to the equation fitted from the numerical values of the samples randomly inspected in this experiment, the goodness of fit R 2 of this straight line is 0.8289, as shown in Equation (2):

[0156] (2);

[0157] Using this actual fitted equation to predict the quality change of the randomly inspected samples (that is, extending the change trend of this equation until the mass loss reaches 0), as shown in Equation (23):

[0158] (23);

[0159] Compared with Equation (2), the goodness of fit R 2 of this straight line is 0.9332, and R 2 The fitting effect tends to a higher value, indicating that the credibility of using this equation to predict the long-term quality change trend of the randomly inspected samples is relatively high and it is scientific.

[0160] As Figure 6 shown, the equations of formula (22) and formula (23) are visually presented in a unified layer. The biochemical consumption prediction curve for the quality of the sampled products indicates that it takes 27 years for the sample quality to finally tend to 0 g. For the wear and breakage prediction curve, it takes about 12 years for the sample quality to tend to 0 g. The service life of this filter material is shorter than the biochemical consumption prediction period. The reason is that in actual situations, the sampled products in the filter tank will be affected by various factors such as temperature, pH, influent water quality, backwashing intensity, etc., resulting in a higher mass loss than the theoretical value and reducing the service life. However, it is still longer than the service life of common filter materials commonly used in the market and is more economical and efficient.

[0161] As Figure 7 shown, the equations of formula (2) and formula (22) are jointly applied to evaluate the mass loss trend of the sampled products within 500 days. For the actual wear and breakage curve, in the early stage of the filter tank operation, the sampled products are affected by various environmental factors, resulting in a relatively large mass loss value for some samples and deviating from the overall discrete distribution. In the middle and late stages of operation, the sampled products have gradually adapted to the water quality and operating conditions in the filter tank, so the deviation trend gradually decreases. The predicted mass change trend and law of the actual wear and breakage curve can more accurately provide reference and basis for actual applications, and the fitting straight line R 2 > 0.7, further enhancing the scientificity.

[0162] Example 3: Determination of the service life of quartz sand filter material

[0163] In this example, a downward-flow denitrifying biological filter is used, with quartz sand as the filter material. The influent COD concentration is 50.1 mg / L, pH < 7, the total nitrogen in the effluent < 10 mg / L, the air washing time is 5 min, the intensity ≤ 27.78 L / (m 2 ·s), the water washing time is 10 min, the intensity ≤ 4.17 L / (m 2 ·s), the air-water combined washing time is 8 min, the intensity ≤ 15.5 L / (m 2 ·s), and the effluent filtration rate is 6 m / h.

[0164] Let the maximum specific surface area of the spherical quartz sand filter material with a particle size range of 1.7 - 3.3 mm be , the maximum particle size be ; the specific surface area of the sampled product sphere be , the diameter be ; the marked hole diameter of the sampled product sphere be , and the specific surface area of the spherical crowns on both sides of the marked hole be . When the specific surface area of the sampled product after deducting the hole crowns ( - ) When it is equal to the specific surface area of the maximum particle size of quartz sand filter media According to the above formula (4), the maximum particle size of the ordinary filter media in the filter tank is related to the particle size of the sampled product and the diameter of the marked hole of the sphere as shown in Table 2 below.

[0165] Table 2 Sphere diameters of quartz sand filter media under different multiple relationships

[0166]

[0167] Based on the data calculated in the above table, select the sampled quartz sand sample with a particle size of 3.63 mm. According to its physical and chemical properties, the density of quartz sand is usually taken as 2.43 g / m 3 Therefore, the initial sample mass is calculated to be 0.61 g.

[0168] (24);

[0169] Taking the quartz sand filter media in the denitrifying biological filter as the sampling object, a certain number of filter media particles are taken as samples at fixed intervals (T = 20 days), and 50 cycles are continuously sampled. Based on the obtained sampling data and combined with the above formula (5), a linear function relationship formula (3) for the change of the service life of quartz sand is established, and a quartz sand wear and breakage curve ( Figure 8 ) is obtained. The goodness of fit of this curve R 2 = 0.7358.

[0170] (3);

[0171] Using this actual quartz sand wear and breakage curve to predict the change in the mass of the sampled product (that is, extending the change trend of this curve until the mass loss reaches 0), an equation (25) is established, and a quartz sand wear and breakage prediction curve ( Figure 9 ) is obtained. The goodness of fit of this curve R 2 = 0.9125.

[0172] (25);

[0173] After extending the change trend of the actual quartz sand wear and breakage curve, the goodness of fit of the equation is improved, indicating that the credibility of using this prediction equation to estimate the service life of quartz sand is relatively high. This prediction method can not only reasonably predict the service life of pyrite filter media, but also be applicable to common ordinary filter media on the market, strongly demonstrating the universality of this prediction method.

[0174] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for identifying and screening chaotic samples based on the determination of filter material use cycle, characterized in that: The steps include: (1) Processing of samples to be inspected: Get the maximum particle size of the filter material to be tested ; Make the particle size of the sample to be processed The maximum particle size of the filter material to be tested 1.0~1.1 times of the weight of the sample to be processed; drilling the sample to be processed to obtain a drilled sample, the drilled sample and the filter material to be tested have the same reaction specific surface area; inserting a magnetic metal segment into the pores of the drilled sample, and sealing and covering the two ends of the pores of the drilled sample with colored resin to obtain a marked sample; taking the lowest weight of a single marked sample as the reference weight, making the weight of all the marked samples equal to the reference weight, and obtaining the sample to be tested; (2) Random inspection of samples: The sample to be inspected is put into the filter tank, so that the sample to be inspected and the filter material to be inspected are operated in the same environment; according to the sampling cycle, through strong magnetic attraction, or / and colored resin, or / and particle size, when the filter layer particles are in an expanded and suspended state at the peak of the air-water backwashing intensity, the sample to be inspected is randomly inspected to obtain the sample; The processing of the sample to be sampled in step (1) includes the following specific steps: (1-1) Collect the particle size range of the filter material to be tested and obtain the maximum particle size of the filter material to be tested ; Make the particle size of the sample to be processed The maximum particle size of the filter material to be tested 1.0~1.1 times of the particle size of the sample to be processed , obtaining the drilling diameter of the sample to be processed; (1-2) drilling the sample to be processed according to the drilling diameter of the sample to be processed to obtain a drilled sample, wherein the drilled sample has the same reaction specific surface area as the filter material to be tested; inserting a magnetic metal segment into the pores of the drilled sample, and sealing and covering both ends of the pores of the drilled sample with a colored resin to obtain a marked sample; (1-3) uniformly weighing the marked samples for inspection, taking the lowest weight of a single marked sample for inspection as the reference weight, grinding the marked samples for inspection that exceed the reference weight so that the weight of all the marked samples for inspection is equal to the reference weight, and obtaining the samples for inspection to be inspected; The specific method of obtaining the drilling diameter of the sample to be processed in step (1-1) is as follows: the drilling diameter of the sample to be processed is calculated by the following formula (1); formula (1) is as follows: （1）； In formula (1) is the particle size of the sample to be processed, N is the diameter of the drill hole of the sample to be processed, and the value range of N is 1.0~1.

1.

2. The method for identifying and screening chaotic samples based on the determination of filter material use cycle according to claim 1, characterized in that: The magnetic metal segment in step (1-2) comprises an alloy of one or at least two of iron, nickel and cobalt; the diameter of the magnetic metal segment is not greater than the borehole diameter of the sample to be processed, and the length of the magnetic metal segment is less than the borehole length of the sample to be processed; The colored resin in step (1-2) includes at least one of colored epoxy resin, alkyd resin, phenolic resin and polyurethane resin.

3. The method for identifying and screening chaotic samples based on the determination of filter material use cycle according to claim 1, characterized in that: The random inspection of the samples in step (2) includes the following specific steps: (2-1) placing the sample to be inspected into a specific range of the filter layer of the filter tank, so that the sample to be inspected and the filter material to be inspected are operated in the same environment; (2-2) According to the sampling period, the sample to be inspected is randomly selected within the specific range by strong magnetic attraction, and / or colored resin, and / or particle size, when the filter layer particles are in an expanded and suspended state at the peak of the air-water backwash intensity, to obtain the sample to be inspected.

4. The method for identifying and screening chaotic samples based on the determination of filter material use cycle according to claim 3 is characterized in that: In step (2-1), the specific range of the filter layer of the filter tank is obtained by a perforated enclosure; the side length of the perforated enclosure is 1.2m~2m, and the height of the perforated enclosure exceeds the filter tank flooding by more than 20 cm.

5. The method for identifying and screening chaotic samples based on the determination of filter material use cycle according to claim 3, characterized in that: In step (2-2), the sampling period interval is at least 10 days, and the continuous sampling is at least 50 periods.

6. Application of the sample sampled by the method for identifying and screening chaotic samples based on the determination of the filter material use period as described in any one of claims 1 to 5 in the construction of a model for the determination of the use period of the filter material to be tested.

7. A method for constructing a model for measuring the service life of a filter material, characterized in that: The method comprises the following steps: recording the quality data of each sampling period of the random inspection sample of the chaotic sample identification and screening method based on the determination of the filter material use period as described in any one of claims 1 to 5, and fitting the mass loss curve; and determining the use period of the filter material to be inspected according to the fitted mass loss curve.

8. The method for constructing a model for measuring the service life of a filter material according to claim 7, characterized in that: When the filter material to be tested is pyrite filter material, the equation of the mass loss curve is shown in formula (2): （2）； In formula (2), x is the service life of pyrite filter material; y is the mass of pyrite filter material corresponding to a certain period; When the filter material to be tested is quartz sand filter material, the equation of the mass loss curve is shown in formula (3): （3）； In formula (3), x is the service life of quartz sand filter material; y is the mass of quartz sand filter material corresponding to a certain period.

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