Combined filler for sewage treatment process and controllable MBBR (Moving Bed Biofilm Reactor) sewage treatment process

Abstract

The invention provides a combined filler for a sewage treatment process and a controllable MBBR (Moving Bed Biofilm Reactor) sewage treatment process, and belongs to the technical field of sewage treatment. The invention provides a combined filler for a sewage treatment process. The combined filler comprises a mixed filler and a container for loading the mixed filler, the mixed filler comprises a hard filler and a soft filler; and the container is a porous container. The combined filler provided by the invention does not block various equipment, mixed fillers in a container collide with each other and are easy to hang mud and demould, and the proportion of soft and hard fillers in the filler is easy to adjust, so that the normal operation of sewage treatment is ensured, the controllability of sewage treatment is realized, and the service life of the filler is prolonged. The problems which are difficult to overcome and uncontrollable in an existing moving bed bio-membrane reactor sewage treatment technology can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a combined filler for a sewage treatment process and a controllable MBBR sewage treatment process. Background Art

[0002] Moving bed biofilm reactor (MBBR) sewage treatment technology is a sewage treatment process that combines the activated sludge method and the biofilm method. Existing MBBR uses floating fillers (such as plastic fillers) as carriers of biofilms. These fillers move freely in the reactor, increasing the contact area of ​​microorganisms and improving the reaction efficiency. They also have a small footprint, strong processing capacity, flexible operation, good adaptability to water quality fluctuations, and good improvement in sludge settling properties. It can effectively remove pollutants such as nitrogen and phosphorus, and is suitable for a variety of scenarios such as urban sewage and industrial wastewater. However, the existing MBBR sewage treatment technology has some difficult-to-overcome uncontrollable problems. For example, the fillers in the reactor are in a fluidized state due to aeration and the lifting effect of water flow. In actual operation, extremely dispersed fillers are prone to local filler accumulation and floating, and there is less filler in other places, resulting in uneven fluidization reaction; the fillers are easy to flow to places where they should not go, causing blockage of pipes, pumps and other equipment, and sometimes causing accidents that cannot be operated. Even if a barrier net is added during the design and construction of sewage treatment equipment, it often causes blockage at the barrier net. Once the barrier net is broken, the filler will leak out of the net. If hard fillers are used, it is not easy to get mud and cannot effectively provide a bacterial growth environment. If sponge-like soft fillers are used, it is easy to get mud, but it is difficult to demold. The small and curved gaps of sponge-like soft fillers are filled with mud but are not easy to fall off, which is equivalent to reducing the treatment area and reducing the sewage treatment efficiency. Therefore, it is urgent to design a filler to achieve the controllability of MBBR sewage treatment process to solve the above problems. Summary of the invention

[0003] In order to solve some difficult-to-overcome uncontrollable problems in the MBBR sewage treatment technology in the prior art, the present invention provides a combined filler for a sewage treatment process, which realizes the controllability of the MBBR sewage treatment process and makes it applicable to the MBBR sewage treatment technology.

[0004] The present invention provides a combined filler for a sewage treatment process, comprising: a mixed filler and a container for loading the mixed filler;

[0005] The mixed filler includes hard filler and soft filler;

[0006] The container is a porous container.

[0007] Optionally, the hard filler is a polyethylene hard filler, and the soft filler is at least one of a polyurethane soft filler and a gel soft filler.

[0008] Optionally, the mass ratio of the hard filler to the soft filler is 25-30:2-5.

[0009] Optionally, the combined filler further includes a slow-release carbon source, and the mass ratio of the hard filler, the soft filler and the slow-release carbon source is 25-30:2-5:0-8, wherein the ratio of the slow-release carbon source is not 0.

[0010] Optionally, the slow-release carbon source is at least one of corn cobs, pine bark and corn stalks.

[0011] Optionally, the length of the corn cob is 3-10 cm.

[0012] Optionally, the porous container is at least one of a porous spherical container, a porous cylindrical container, a porous cubic container and a porous tubular container.

[0013] Optionally, the porous container is at least one of a porous spherical container, a porous cylindrical container, a porous cubic container and a porous tubular container, and the volume of the porous container is 10-100L.

[0014] Optionally, the ratio of the mass of the mixed filler to the volume of the porous container is 40-70 g:1 L.

[0015] The present invention also provides a controllable MBBR sewage treatment process, which uses the combined filler described in any of the above technical solutions, and comprises the following steps:

[0016] S1: connect multiple combined fillers in series to form a set of sewage treatment units; repeat this step to provide multiple sets of sewage treatment units

[0017] S2: multiple groups of sewage treatment units are arranged in parallel above the aeration device of the sewage treatment tank and immersed in the water body;

[0018] S3: Start the aeration device to treat sewage.

[0019] Optionally, the spacing between the combined fillers in each group of sewage treatment units is 0.3-1.5 m, and the spacing between each group of sewage treatment units is 0.8-1.5 m.

[0020] In the combined filler provided by the present invention, the hard filler and the soft filler are loaded in a porous container, and the filler will not float around in the water, so it will not block various equipment, ensuring the normal operation of sewage treatment. In addition, when the hard filler and the soft filler are placed in the same container and sewage treatment is carried out, the hard filler and the soft filler collide and squeeze in the container, and the sludge on the soft filler will partially fall off and enter the gap of the hard filler nearby, adhere and grow, which helps to help the hard filler to hang mud, and realize the demoulding of the soft filler, thereby increasing the area of ​​sewage treatment. In addition, the combined filler is easy to replace, the mixed filler in the container is easy to adjust, and the number of containers is easy to increase or decrease, thereby realizing the controllability of sewage treatment.

[0021] In addition, due to the high sludge concentration in the container, the volume of sludge attached to the filler increases, showing an anaerobic state inside, anoxic in the middle, and aerobic outside, forming a dissolved oxygen gradient, carbon source gradient, sludge concentration gradient and pH gradient inside and outside the container. The ammonia nitrogen in the sewage outside the combined filler is easily oxidized to nitrite nitrogen or nitrate nitrogen in an environment with low carbon source, high dissolved oxygen and low sludge concentration. After flowing through the inside of the combined filler, it is easily reduced to nitrogen gas by facultative oxic bacteria in an environment with high carbon source, low dissolved oxygen and high sludge concentration, and escapes from the water body, realizing the short-range nitrification and denitrification and synchronous digestion and denitrification state of sewage treatment. The pH gradient inside and outside the container decreases with the exchange of water flow, so that the pH outside the container will not be too low. Phosphorus is released in the anaerobic state of the sludge, and is excessively adsorbed in the aerobic environment. It is discharged from the system with the sludge, which can achieve the effect of nitrogen and phosphorus removal in the same pool, and the anaerobic tank and anoxic tank of the existing sewage treatment process can be omitted, and it is expected to omit the internal reflux pump, laying the foundation for reducing sewage treatment investment and reducing operating costs.

[0022] The present invention also provides a controllable MBBR sewage treatment process, which uses the combined material described in the above technical solution, connects multiple combined fillers in series to form a group of sewage treatment units, and repeatedly provides multiple groups. The multiple groups of sewage treatment units are arranged in parallel above the aeration device of the sewage treatment tank and immersed in the water body. At this time, the aeration device is turned on. When the sewage is fluidized, the fillers will not be gathered together, but will float up and down and roll left and right within a controllable range, so that the sewage can be evenly in contact with the fillers, thereby solving the problem of local accumulation and floating of the fillers and running around to block the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other objects, features and advantages of the present invention will be apparent from the following description of preferred embodiments and accompanying drawings which illustrate the subject matter of the present invention and its use, in which:

[0024] Figure 1 Schematic diagram of PE hard filler mud hanging provided in an embodiment of the present invention.

[0025] Figure 2 Schematic diagram of PE hard filler used in an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the PU soft filler used in the embodiment of the present invention.

[0027] Figure 4 Schematic diagram of a porous spherical container used in an embodiment of the present invention.

[0028] Figure 5 Schematic diagram of a porous spherical container with circular holes.

[0029] Figure 6 This is a schematic diagram of a porous spherical container with oblong holes.

[0030] Figure 7 A cross-sectional schematic diagram of the installation of the composite filler provided in an embodiment of the present invention in a sewage treatment tank.

[0031] Figure 8 A schematic top view of the installation of the composite filler provided in an embodiment of the present invention in a sewage treatment tank. DETAILED DESCRIPTION

[0032] The present invention will be described below by specific embodiments, and it will be appreciated by those skilled in the art that the specific embodiments below are only for illustrative purposes, and do not limit the scope of the present invention in any way. In addition, in the following embodiments, unless otherwise specified, the materials and equipment used are all commercially available. If in the following embodiments, specific treatment conditions and treatment methods are not clearly described, then conditions and methods known in the art can be used to process.

[0033] The present invention provides a combined filler for a sewage treatment process, comprising: a mixed filler and a container for loading the mixed filler;

[0034] The mixed filler includes hard filler and soft filler;

[0035] The container is a porous container.

[0036] In the combined filler provided by the present invention, the hard filler and the soft filler are loaded in a porous container, and the filler will not float around in the water, so it will not block various equipment, ensuring the normal operation of sewage treatment. In addition, when the hard filler and the soft filler are placed in the same container and sewage treatment is carried out, the hard filler and the soft filler collide and squeeze in the container, and the sludge on the soft filler will partially fall off and enter the gap of the hard filler nearby, adhere and grow, which helps to help the hard filler to hang mud, and realize the demoulding of the soft filler, thereby increasing the area of ​​sewage treatment. In addition, the combined filler is easy to replace, the mixed filler in the container is easy to adjust, and the number of containers is easy to increase or decrease, thereby realizing the controllability of sewage treatment.

[0037] In addition, due to the high sludge concentration in the container, the volume of sludge attached to the filler is large, presenting an anaerobic state inside, anoxic in the middle, and aerobic outside, forming a dissolved oxygen gradient, carbon source gradient, sludge concentration gradient and pH gradient inside and outside the container. The ammonia nitrogen in the sewage outside the combined filler is easily oxidized to nitrite nitrogen or nitrate nitrogen in an environment with low carbon source, high dissolved oxygen and low sludge concentration. After flowing through the inside of the combined filler, it is easily reduced to nitrogen gas by facultative oxic bacteria to escape from the water body in an environment with high carbon source, low dissolved oxygen and high sludge concentration, realizing the short-range nitrification and denitrification and synchronous digestion and denitrification state of sewage treatment. The pH gradient inside and outside the container decreases with the exchange of water flow, so that the pH outside the container will not be too low. Phosphorus is released in the anaerobic state of the sludge, and is excessively adsorbed in the aerobic environment. It is discharged from the system with the sludge, which can achieve the effect of nitrogen and phosphorus removal in the same pool, and the anaerobic tank and anoxic tank of the existing sewage treatment process can be omitted, and it is expected to omit the internal reflux pump, which can greatly save operating costs.

[0038] In some embodiments of the present invention, the hard filler is a polyethylene (PE) hard filler, and the soft filler is at least one of a polyurethane (PU) soft filler and a gel soft filler, preferably a PU soft filler. In the present invention, the PE hard filler has high mechanical strength, is not easily deformed or damaged, and has small cells inside for sludge to adhere to and grow. The sludge hanging condition of the PE hard filler is as follows: Figure 1 As shown in the figure, PU soft filler and gel soft filler have large gaps, sludge can easily grow in the gaps and get stuck with mud. Especially PU soft filler is cheap and suitable for large-scale industrial use.

[0039] In some embodiments of the present invention, the mass ratio of the hard filler to the soft filler is 25-30:2-5, specifically 25:2, 28:5 or 28:3. In the present invention, the hard filler and the soft filler in the above ratio can achieve the best mud hanging effect, which is beneficial to the treatment of sewage.

[0040] In the present invention, when the carbon source in the sewage to be treated is sufficient, no carbon source may be added, and when the carbon source is lacking in the sewage to be treated, a carbon source may be added to the combined filler. In some embodiments of the present invention, the combined filler also includes a slow-release carbon source, and the mass ratio of the hard filler to the slow-release carbon source is 25-30:0-8, wherein the ratio of the slow-release carbon source is not 0, and at this time the mass ratio of the hard filler, the soft filler and the slow-release carbon source is 25-30:2-5:0-8, preferably 25-30:2-5:3-8, and specifically 25:2:3, 28:5:8 or 28:3:3 can be selected. In the embodiment of adding a slow-release carbon source of the present invention, the hard filler, soft filler and slow-release carbon source in the above-mentioned specific ratio squeeze and collide with each other, so that the sludge on the soft filler and the slow-release carbon source is scraped off by the hard filler and enters the pores of the hard filler, and the mud hanging effect of the hard filler and the mud removal effect of the soft filler are optimal, forming an environment suitable for the growth of beneficial bacteria, and the sludge on the surface of the slow-release carbon source is scraped away, leaking out the fresh surface, and the soluble carbohydrates will continuously dissolve into the water, playing a role in continuously supplementing the carbon source. In addition, the combined filler is easy to replace, and the mixed filler and slow-release carbon source in the container are easy to adjust, realizing the controllability of sewage treatment. In addition, compared with the prior art, the present invention can save 40% of the carbon source dosage and one-third of the oxygen demand, which can greatly save the operating cost.

[0041] The present invention has no special limitation on the shapes of the hard filler and the soft filler, and the commonly used honeycomb or porous fillers in the art can be used. In some embodiments of the present invention, the shape of the polyethylene hard filler is at least one of a cylinder with a honeycomb structure inside, a sphere with a honeycomb structure inside, a porous cube, a porous sheet, and a porous cuboid; the shape of the polyurethane soft filler is at least one of a porous sheet, a porous cylinder, a honeycomb or a porous sphere, a porous cube, and a porous irregular shape. In the embodiments of the present invention, the hard filler is as follows: Figure 2 As shown in the figure, it is a cylinder with a honeycomb structure inside, sludge can easily enter it, and the sludge is easy to fall off after aging; soft fillers such as Figure 3 As shown, it is a porous cube. The soft filler of this shape is easy to process and has a low price. Other shapes are difficult to process, expensive, and have a low cost-performance ratio, but the use effect is comparable.

[0042] In some embodiments of the present invention, the slow-release carbon source is at least one of corn cobs, pine bark and corn stalks, preferably corn cobs. In the present invention, corn cobs, pine bark and corn stalks are all byproducts of agricultural and forestry crops, do not require complex synthesis processes, and are inexpensive. In particular, corn cobs have an organic matter content of 91.3%, of which soluble carbohydrates are 58.4%, and can be easily processed and loaded into the container used, and are a good carbon source material with a long service life.

[0043] In some embodiments of the present invention, the length of the corn cob is 3-10 cm, preferably 4-6 cm. In the present invention, if the corn cob is too long, the nutrient dissolution effect is poor; if it is too short, it is difficult to process and is easy to leak from the pores; the corn cob of the above length has both good nutrient dissolution effect and is easy to process, and can achieve a good carbon source release effect.

[0044] In some embodiments of the present invention, the porous container is at least one of a porous spherical container, a porous cylindrical container, a porous cubic container and a porous tubular container. In an embodiment of the present invention, the porous container is a porous spherical container, such as Figure 4 As shown in the figure, the porous spherical container is easier to roll in the process of water fluidization, which is more conducive to the mutual squeezing and scraping of various fillers. The sludge in the soft filler and on the surface of the slow-release carbon source is more likely to enter the hard filler.

[0045] In some embodiments of the present invention, the volume of the porous container is 10-100L, specifically 30L, 40L, 50L, 55L, 65.4L or 73.5L; the present invention has no special limitation on the hole type and hole diameter or single hole area of ​​the porous container, as long as the filler does not leak out and the water can flow in and out easily. Specifically, the hole can be circular, elliptical, oblong, square or polygonal. Figure 5 and Figure 6 The shapes of circular holes and oblong holes are shown as examples. If the volume of the porous container is too small and the amount of filler is small, the fillers will squeeze each other in it, and there will be less chance of scratching, so that the difference between the environment inside and outside the container is small, and the impact on sewage treatment is small; if the volume of the porous container is too large, it is difficult for water to flow into the interior, and the weight of the sludge after growth is too large, which greatly increases the difficulty of manual removal and placement, and there will be operational hazards. The volume and single hole shape within the above range can form a good internal environment, and the difficulty of manual removal and placement is also small, which is suitable for actual operation.

[0046] In some embodiments of the present invention, the ratio of the mass of the mixed filler to the volume of the porous container is 40-70g:1L, specifically 40g:1L, 42.8g:1L, 45g:1L, 47.4g:1L, 50g:1L, 52g:1L, 54g:1L, 56g:1L, 58g:1L and 60g:1L. When the amount of the mixed filler and the slow-release carbon source is too small, the filler is easy to roll, but the available volume is also small, and the effect is poor; on the contrary, the filler is not easy to roll, the amount of sewage entering is small, the internal sludge is not easy to escape, and the treatment effect will also be poor. The ratio within the above range is moderate, which can ensure that the filler rolls effectively, and at the same time the amount of sewage entering is moderate, which ensures that the sludge is easy to escape and the sewage is effectively treated.

[0047] The present invention also provides a sewage treatment process using the above-mentioned combined filler, comprising the following steps:

[0048] S1: connect multiple combined fillers in series to form a set of sewage treatment units; repeat this step to provide multiple sets of sewage treatment units.

[0049] S2: multiple groups of sewage treatment units are arranged in parallel above the aeration device of the sewage treatment tank and immersed in the water body;

[0050] S3: Start the aeration device to treat sewage.

[0051] like Figure 7 and Figure 8 As shown, the sewage treatment process provided by the present invention connects multiple combined fillers in series to form a group of sewage treatment units, repeatedly provides multiple groups of sewage treatment units, and fixes them in the sewage treatment pool, and then turns on the aeration device. When the sewage is fluidized, there is a fixed distance between the combined filler and the sewage treatment unit, and they are fixed, so that the filler container will not gather together, but the combined filler will float up and down and roll left and right within a controllable range, so that the sewage can evenly contact the combined filler, solving the problem of local accumulation and floating of the filler and running around to block the equipment.

[0052] In some embodiments of the present invention, the spacing between the combined fillers in each group of sewage treatment units is 0.3-1.5m, and the spacing between each group of sewage treatment units is 0.8-1.5m. In the present invention, the spacing between the combined fillers in each group of sewage treatment units can be specifically 0.3m, 0.5m or 1m, and the spacing between each group of sewage treatment units can be specifically selected as 1m, 1.2m or 1.5m. In an embodiment of the present invention, the spacing between the combined fillers in each group of sewage treatment units is selected as 0.5m, and the spacing between each group of sewage treatment units is selected as 1.2m. If the spacing between the combined fillers in each group of sewage treatment units is too small, the two containers may collide and rub against each other during operation, increasing unnecessary losses. If the spacing is too large, it is equivalent to reducing the fillers that can be used to treat sewage, which will make the sewage treatment effect worse; because the combined fillers are strung together with ropes, the distance between each group is too small, and the two groups will collide with each other, and in serious cases, they will be mixed together. If the distance is too large, it is equivalent to reducing the number of combined fillers, which will also affect the treatment effect. When the distance between the sewage treatment units is 0.8-1.5m, the sewage treatment units will not collide with each other during operation and can operate normally.

[0053] The distance between the combined fillers in each group of sewage treatment units and the distance between each group of sewage treatment units are determined according to the pool depth. The greater the pool depth, the smaller the spacing, and vice versa. In the embodiment of the present invention, the spacing is set at ≥ 0.4 70L containers per cubic effective pool volume.

[0054] The technical scheme of the present invention will be described clearly and completely below in conjunction with the accompanying drawings and embodiments. The embodiments of the present application are only used as examples, and all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0055] The inlet water quality in the following examples and comparative examples is as follows:

[0056] Influent water quality: COD 140-379mg / L, ammonia nitrogen 30-60mg / L, total phosphorus 3-8mg / L, pH 6-9.

[0057] The test site of the following embodiments and comparative examples is the Yangzhao sewage treatment station in Jishan County. Unless otherwise specified, the sewage treatment process in the embodiments and comparative examples is: domestic sewage collection pipeline → grid → regulating tank → anaerobic tank → anoxic tank → aerobic tank → secondary sedimentation tank → microecological filter bed → clean water tank → discharge. In the embodiments and comparative examples, the conditions of other treatment tanks remain unchanged, and only the composition and ratio of the combined filler in the aerobic tank are changed. Two aerobic tanks are used in series in the process, and the specifications of the aerobic tank are: length * width * height = 7m * 2.2m * 2.6m, and the effective use volume is 70m 3 , Designed water treatment capacity: 200m 3 / d, designed hydraulic retention time is 8 hours.

[0058] The following examples and comparative examples were all conducted in an aerobic pool. The porous spherical containers used in the examples and comparative examples are all plastic porous spherical containers with a capacity of 65.4L, a hexagonal hole shape, and a hole diameter (the longest diameter of the hexagon) of 20mm; the PE hard filler is a cylinder with a diameter of 25mm and a height of 10mm and a honeycomb structure inside; the PU soft filler is a porous cube with a side length of 40mm; the elastic filler is a Φ150*1500 elastic filler, which is a filler string processed from polyethylene filaments, which is folded into a ball and placed in the container when used; the gel filler is a porous cube with a side length of 35mm

[0059] Example 1

[0060] 2.5 kg of PE hard filler and 0.3 kg of PU soft filler were packaged in a porous spherical container to obtain a combined filler.

[0061] Comparative Example 1

[0062] 0.25 kg of PE hard filler was filled into a mesh bag to obtain a composite filler.

[0063] Comparative Example 2

[0064] 0.2 kg of PE hard filler and 0.05 kg of PU soft filler were filled into a mesh bag to obtain a combined filler.

[0065] Comparative Example 3

[0066] 5 kg of PE hard filler was packaged in a porous spherical container to obtain a composite filler.

[0067] Comparative Example 4

[0068] 0.6 kg of the gel filler was packaged in a porous spherical container to obtain a composite filler.

[0069] Comparative Example 5

[0070] 2.5 kg of hard filler and 1 piece of elastic filler were packed in a porous spherical container to obtain a combined filler.

[0071] The MBBR process was used to hang the combined fillers of Example 1 and Comparative Examples 1-5 in an aerobic tank to conduct a mud hanging experiment. After 10 days, it was found that a small amount of mud hung in the combined fillers of Example 1 and Comparative Examples 3-4; while the fillers of Comparative Examples 1-2 and Comparative Example 5 were still almost free of mud after 30 days.

[0072] Comparative Example 6

[0073] The same sewage as in Example 1 was treated by using a membrane bioreactor (MBR) sewage treatment process. 3 10kg of PE hard filler was added to the MBR pool. After 30 days, the PE hard filler was salvaged and it was found that there was almost no mud on the PE hard filler.

[0074] From the comparison of the mud hanging effects of Comparative Examples 1, 3 and 6, and the comparison of the mud hanging effects of Example 1 and Comparative Example 2, it can be seen that the use of a porous container to load the filler is conducive to mud hanging, and thus is conducive to sewage treatment. From the comparison of the mud hanging effects of Example 1 and Comparative Examples 3-5, it can be seen that when the filler is loaded in a porous container, the combination of PE hard filler and PU soft filler is conducive to accelerating mud hanging.

[0075] Example 2

[0076] The composite filler of Example 1 was suspended in the aerobic tank of the aforementioned MBBR process, and glucose was continuously added as a carbon source in the anoxic tank using a metering pump to treat the sewage, and the amount of sludge hanging on the composite filler was detected, wherein the amount of glucose added was 5 kg / day.

[0077] Comparative Examples 7-9

[0078] The combined fillers of Comparative Examples 3-5 were tested for the amount of sludge by using the same method as in Example 2 (the combined fillers of Comparative Examples 3-5 and the combined fillers of Example 2 were hung in the same aerobic tank to ensure that other conditions were the same). The tests using the combined fillers of Comparative Examples 3-5 are referred to as Comparative Examples 7-9 in turn.

[0079] On the 10th day of the test, the amount of mud hanging on the combined fillers in Example 2 and Comparative Examples 7-9 (the amount of sludge added in each combined filler) was 2.8kg, 1.9kg, 3.1kg and 1.65kg, respectively. From the above results, it can be seen that the gel filler has the best mud hanging; the combination of PE hard filler and PU soft filler is second, but it is close to the mud hanging situation of the gel filler; the whole PE hard filler is poor; the combination of 2.5kg PE hard filler and elastic filler is the worst. It can be seen that although the mud hanging situation of the combined filler of PE hard filler and PU soft filler is slightly worse than that of the gel filler, it can significantly reduce the cost.

[0080] Example 3

[0081] 2.5 kg of PE hard filler, 0.3 kg of PU soft filler and 3 whole corn cobs (0.3 kg, corn cobs with a length of 17-23 cm, used as a slow-release carbon source) were packaged in a porous spherical container to obtain a combined filler.

[0082] Comparative Examples 10-12

[0083] Similarly, 3 whole corn cobs (0.3 kg, with a corn cob length of 17-23 cm, as a slow-release carbon source) were added to the combined fillers of Comparative Examples 3-5, respectively as Comparative Examples 10-12.

[0084] The above-mentioned MBBR process was used to hang the combined fillers of Example 3 and Comparative Examples 10-12 in the same aerobic tank to conduct a sludge test. On the 7th day of the test, the sludge amount of the combined fillers of the Example and the Comparative Example was higher than that of the corresponding combined fillers without any carbon source added, but the increase was not large, indicating that the addition of the slow-release carbon source increased the sludge amount of the sludge.

[0085] Example 4

[0086] The composite filler was prepared according to the method of Example 3, except that the corn cobs were cut into a length of 8-12 cm.

[0087] Comparative Examples 13-15

[0088] The corn cobs in the combined fillers of Comparative Examples 10-12 were cut into lengths of 8-12 cm, and the obtained combined fillers were used as Comparative Examples 13-15 respectively.

[0089] The above-mentioned MBBR process was adopted, and the combined fillers of Example 4 and Comparative Examples 13-15 were suspended in the same aerobic tank to conduct a sludge test. On the fifth day of the test, the amount of sludge attached to the combined fillers of the Example and Comparative Example was significantly higher than that of the corresponding combined fillers with whole corn cobs added as a slow-release carbon source, indicating that the length of the corn cob affects the speed of sludge attachment, and the use of truncated corn cobs can increase the amount of sludge attached to the sludge relative to the whole corn cob as a slow-release carbon source.

[0090] Example 5

[0091] The composite filler was prepared according to the method of Example 3, except that the corn cobs were cut into a length of 4-6 cm.

[0092] Comparative Examples 16-18

[0093] The corn cobs in the combined fillers of Comparative Examples 10-12 were cut into lengths of 4-6 cm, and the obtained combined fillers were used as Comparative Examples 16-18 respectively.

[0094] The MBBR process described above was used to hang the combined fillers of Example 5 and Comparative Examples 16-18 in the same aerobic tank for a sludge hanging test. On the 12th day of the test, the sludge concentration in each combined filler and the sludge concentration outside the combined filler were tested, wherein the sludge concentration in the combined filler was obtained by hanging the combined filler out of the water and then testing the sludge concentration therein, each concentration was tested three times, and the average value was taken as the final concentration; since the combined filler was located in the same aerobic tank, the sludge concentration outside the combined filler was the same. The test results are shown in Table 1 below.

[0095] Table 1 Sludge concentration inside and outside the combined filler

[0096]

[0097] The sludge concentrations in the combined fillers of Example 5 and Comparative Examples 16-18 in Table 1 are not much different. It may be that during the process of lifting the combined filler, most of the water outside the filler is lost, and the sludge taken is mainly the sludge in the filler, and the sludge concentration in the filler is not much different. However, the above results can show that a sludge concentration gradient can be formed inside and outside the combined filler, which is conducive to forming an anaerobic state inside, anoxic in the middle, and aerobic outside. In addition, it can be observed that the formed sludge flocs are large and have good sedimentation properties, indicating that the activity is strong.

[0098] The sludge increase of the combined fillers of Example 5 and Comparative Examples 16-18 was tested, and the results were 2.32kg, 1.37kg, 2.64kg and 0.96kg, respectively. It can be seen that when corn cobs are used as carbon sources, gel fillers hang mud the fastest, but the price is high and the desludging effect is poor. A large amount of anaerobic sludge will accumulate in the filler and become dead mud. After long-term sewage treatment, the sewage treatment effect will deteriorate; the combined filler of PE hard filler and PU soft filler has the second best mud hanging effect, but it is very close to the gel filler, and the sludge in the PE hard filler is easy to fall off, which is more conducive to the generation of new sludge, accelerates the iterative proliferation of bacteria, and improves the sewage treatment effect. It is a better combination; while the combined filler of PE hard filler and elastic filler has the worst effect.

[0099] In addition, the amount of sludge hanging on the combined filler of Example 5 is slightly lower than that of the combined filler of Example 2. However, in Example 5, a slow-release carbon source is used to replace the more expensive glucose. When treating sewage, the metering pump can be omitted, the process is simpler, the cost is lower, and it is suitable for large-scale use in factories.

[0100] Example 6

[0101] 2.8 kg of PE hard filler, 0.3 kg of PU soft filler and 0.3 kg of corn cob (length 4-6 cm) are placed in a porous spherical container to obtain a combined filler;

[0102] Connect 7 combined fillers in series, with the spacing between each combined filler being 0.5 m, to form a set of sewage treatment units; repeat this step to provide 4 sets of sewage treatment units;

[0103] Two sets of sewage treatment units are arranged in parallel above the aeration devices of the two aerobic pools in the above process, with the sewage treatment units 0.5 m away from the pool wall, the distance between the sewage treatment units is 1.2 m, and they are immersed in the water body;

[0104] Start the aeration device to treat sewage;

[0105] The amount of sludge was checked once a day. On the 15th day, the sludge growth was stable and the quality of the sewage effluent was stable.

[0106] The specific test results are shown in Table 1, which are the test results from August to October 2024, where the pH is tested every 10 days.

[0107] Table 1 Monitoring of operation days, effluent water quality parameters and filler mud content

[0108]

[0109]

[0110] The designed effluent water quality in the embodiment is COD≤40mg / L, ammonia nitrogen≤2.0mg / L, total phosphorus≤0.4mg / L, and pH value is 6-9. As shown in Table 1, when the monitoring time is 7 days, the effluent water quality has reached the requirements of the designed effluent water quality. When the operation is 15 days, the sewage treatment reaches stability. When the monitoring is up to 56 days, the treated sewage effluent is still within the design range. The process can continue to operate stably, and after the slow-release carbon source is consumed (about 4 months), the slow-release carbon source can be replenished.

[0111] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A combined filler for a sewage treatment process, comprising: A mixed filler and a container for loading the mixed filler; The mixed filler includes hard filler and soft filler; The container is a porous container.

2. The composite filler according to claim 1, characterized in that: The hard filler is a polyethylene hard filler, and the soft filler is at least one of a polyurethane soft filler and a gel soft filler.

3. The composite filler according to claim 1 or 2, characterized in that: The mass ratio of the hard filler to the soft filler is 25-30:2-5.

4. The composite filler according to claim 1 or 2, characterized in that: The combined filler also includes a slow-release carbon source, and the mass ratio of the hard filler to the slow-release carbon source is 25-30:0-8, wherein the proportion of the slow-release carbon source is not zero.

5. The composite filler according to claim 4, characterized in that: The slow-release carbon source is at least one of corn cobs, pine barks and corn stalks.

6. The composite filler according to claim 5, characterized in that: The length of the corn cob is 3-10 cm.

7. The composite filler according to claim 1, characterized in that: The porous container is at least one of a porous spherical container, a porous cylindrical container, a porous cubic container and a porous tubular container, and the volume of the porous container is 10-100L.

8. The composite filler according to claim 6 or 7, characterized in that: The ratio of the mass of the mixed filler to the volume of the porous container is 40-70 g:1 L.

9. A controllable MBBR sewage treatment process, which uses the combined filler according to any one of claims 1 to 8, comprising the following steps: S1: connect multiple combined fillers in series to form a set of sewage treatment units; repeat this step to provide multiple sets of sewage treatment units; S2: arranging the plurality of sewage treatment units in parallel above the aeration device of the sewage treatment tank and immersing them in the water body; S3: Start the aeration device to treat sewage.

10. The controllable MBBR sewage treatment process according to claim 9, characterized in that: The spacing between the combined fillers in each group of sewage treatment units is 0.3-1.5m, and the spacing between each group of sewage treatment units is 0.8-1.5m.

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