Efficient denitrification suspended filler for river regulation and preparation method of efficient denitrification suspended filler

Abstract

The invention discloses an efficient denitrification suspended filler for river regulation and a preparation method thereof, and belongs to the technical field of water treatment.The preparation method comprises the following steps that sludge-based biochar and PHBV are mixed to prepare a composite biochar mixed filler; loading the composite charcoal mixed filler onto the surface of the polyurethane sponge to form modified polyurethane sponge; placing the modified polyurethane sponge in a reactor for reaction, and finally obtaining the denitrification suspended filler with a biological membrane attached inside. The biochar and the PHBV are subjected to material compounding through ultrasound, so that the water solubility, the reaction activity, the adsorption performance and the biological activity of the material are improved, the modified filler can interact with target pollutants more efficiently, and the purification capacity of the filler is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of water treatment, and particularly relates to an efficient denitrifying suspended filler for river regulation.

Background Art

[0002] With the acceleration of urbanization and the expansion of industrial development, the water environment problems of rivers are becoming increasingly serious. The river water bodies have problems such as hypoxia and eutrophication due to pollution, which seriously affect the health of the aquatic ecosystem and the sustainable development of the city. Water eutrophication is a water pollution phenomenon caused by the excessive discharge of nutrients such as nitrogen and phosphorus in water bodies, and it is a common water quality problem globally. Water eutrophication is mainly due to the discharge of exogenous nutrients, and nitrogen is one of the main factors causing water eutrophication. Therefore, the control of nitrogen-containing pollutants is crucial for the restoration of water eutrophication.

[0003] Currently, the biological membrane method is the most widely used river water treatment process. However, in the actual river water treatment process, the biological membrane method has disadvantages such as slow film formation speed, small amount of biological membrane, and low denitrification efficiency, such as the continuous flow fluidized bed biological membrane composite reactor and the method for deep ammonia and phosphorus removal from sewage developed by Qingdao Water Group Co., Ltd. (Patent Application No. 202411076856). Therefore, a biological membrane filler is needed to achieve the purpose of rapid film formation and efficient denitrification in the river water treatment system.

[0004] In the prior art, traditional porous inorganic fillers such as activated carbon, diatomite, ceramsite, and zeolite, although widely used, have too high density, which is likely to cause air flow resistance and affect the stable operation of equipment; traditional organic substances such as corn cob powder and bamboo powder can provide carriers and carbon sources, but the rate of carbon source release is too fast, resulting in a lack of carbon source for denitrification in the later stage and thus reducing the denitrification efficiency, such as the corn cob filler applied in a high-efficiency denitrifying and phosphorus-removing filler for aquaculture tail water developed by Guangdong Linkun Group Co., Ltd. (Patent Application No. 202410696354.8), while organic polymer fillers such as polyvinyl chloride and polyurethane sponge suspended fillers, although having low density, have smooth and hydrophobic surfaces, resulting in slow film formation in the reactor, affecting the purification efficiency, and limiting their application in river water denitrification, such as the polyurethane sponge cement filler applied in a preparation method of an iron-manganese composite-based porous polyurethane cement sponge filler developed by Dongguan University of Technology (Patent Application No. 202410853176.5). There has not been much use of the synergistic application of organic biodegradable polymer slow-release carbon source fillers and inorganic substances.

Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide an efficient denitrifying suspended filler for river regulation and its preparation method, so as to solve the problems of slow film formation of the existing carrier and low microbial denitrification activity.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] First, a method for preparing an efficient denitrifying suspended filler for river regulation is provided, including the following steps:

[0008] A composite biochar mixed filler is made by mixing sludge-based biochar and PHBV;

[0009] The composite biochar mixed filler is loaded onto the surface of a polyurethane sponge to form a modified polyurethane sponge;

[0010] The modified polyurethane sponge is placed in a bioreactor for reaction, and finally a denitrifying suspended filler with an internal attached biofilm is obtained.

[0011] Preferably, the preparation method of the sludge-based biochar is as follows: First, the surplus sludge after domestic wastewater treatment in a sewage treatment plant is naturally air-dried or heated and dried; then it is mechanically crushed and sieved to obtain the sludge raw materials of the sludge-based biochar; then the raw materials of the sludge-based biochar, including sludge, diatomite, iron powder, and starch, are mechanically mixed and pyrolyzed at high temperature, and after cooling, it is ground and sieved again to obtain the sludge-based biochar.

[0012] Preferably, the mass ratio of the raw materials of the sludge-based biochar is: 65%-75% sludge, 13%-20% diatomite, 7%-10% iron powder, and 5%-8.5% starch.

[0013] Preferably, the high-temperature pyrolysis process is: pyrolysis at 450-600°C in a muffle furnace for 30-50 min; and / or, after cooling, it is ground and sieved again to obtain the sludge-based biochar.

[0014] Preferably, the preparation method of the composite biochar mixed filler is: the sludge-based biochar and PHBV are configured according to a set mass ratio, deionized water is added and stirred evenly; then it is placed in an ultrasonic cleaner for ultrasonic treatment; after the ultrasonic treatment ends, it is left to cool; finally, it is left standing for a set time to obtain the composite biochar mixed filler.

[0015] Preferably, the mass ratio of the sludge-based biochar to PHBV is 2-8:1; and / or, ultrasonic treatment is carried out in an ultrasonic cleaner for 1-3 h, and the ultrasonic power is 250-350 W; and / or, the composite biochar mixed filler is obtained by standing for 10-14 h.

[0016] Preferably, the modification method of the polyurethane sponge is: the composite biochar mixed filler is loaded onto the surface of the polyurethane sponge by using an adhesive.

[0017] Preferably, the adhesive is made by mixing a 1.5-2.5% aqueous sodium alginate solution and a 1.5-2.8% aqueous polyvinyl alcohol solution.

[0018] Preferably, the modified polyurethane sponge is enriched, domesticated, and biofilm-attached in the bioreactor for 11 - 20 days, and finally fished out to obtain a highly efficient nitrogen-removing suspended filler for river treatment with a large amount of biofilm attached inside.

[0019] In addition, the present invention also provides a highly efficient nitrogen-removing suspended filler for river treatment, which is prepared by using the preparation method of the highly efficient nitrogen-removing suspended filler described above.

[0020] The present invention adopts the above technical solution and has the following beneficial effects:

[0021] The suspended filler of the present invention can be used to remove nitrogen-containing pollutants in the river. The components of the highly efficient nitrogen-removing suspended filler for river treatment of the present invention include: a composite biochar mixed filler made by mixing sludge-based biochar and PHBV, and a polyurethane sponge. The composite biochar mixed filler is adhered to the polyurethane sponge through an adhesive.

[0022] Among them, PHBV (3-hydroxybutyrate-co-3-hydroxyvalerate) in the filler can be hydrolyzed into soluble small-molecule substances under the action of microbial extracellular enzymes. These substances participate in the denitrification process as the carbon source and electron donor of microorganisms, thereby promoting water purification effects such as nitrogen removal.

[0023] The sludge-based biochar can immobilize microorganisms on the activated carbon, improve the adsorption capacity of the activated carbon, extend the service life of the activated carbon, and enhance the degradation ability of organic matter in water. The added iron powder has excellent nitrogen adsorption performance, can effectively remove nitrogen elements in river water and increase the activity of microorganisms in the biofilm. The sludge-based biochar and iron powder act together to enhance the indirect nitrogen-removing function of iron elements. The present invention composites the composite biochar mixed filler and PHBV by ultrasonic, thereby improving its water solubility, reaction activity, adsorption performance, and biological activity, enabling the rapid enrichment of the microbial biofilm amount, making the modified filler interact more efficiently with target pollutants, and enhancing the purification ability of the filler.

[0024] By using a polyurethane sponge with a large specific surface area as a carrier, it provides a suitable microbial growth environment and is conducive to the rapid formation of biofilm.

[0025] The filler of the present invention provides a suitable microenvironment, which is conducive to the enrichment of microorganisms related to nitrogen removal (such as nitrifying bacteria). The porous structure and hydrophilic surface of the filler provide good attachment points for microorganisms, promote the formation of biofilm, and enable it to show higher purification efficiency when treating river water.

[0026] By surface-loading the composite biochar mixed filler, this filler is conducive to the rapid formation of biofilm and the carried PHBV has the function of promoting the activity of microbial nitrogen-removing related enzymes, thereby improving the nitrogen removal effect.

[0027] The present invention can flexibly adjust the proportion of composite biochar mixed fillers and PHBV according to different water quality conditions, and can efficiently remove nitrogen in rivers with different pollution conditions.

[0028] In the technical solution of the present invention, the filler will not degrade when soaked in wastewater for a long time, nor will it be toxic to microorganisms. Compared with other materials such as polyvinyl chloride, the filler has better chemical corrosion resistance and biocompatibility, can maintain stable performance in a complex environment, and ensure the long-term use effect of the filler.

[0029] The filler of the present invention can provide a good growth environment for microorganisms. The microorganisms have high activity on the filler and can rapidly degrade organic matters and other pollutants in the wastewater, further improving the water quality purification effect.

[0030] These characteristics and advantages of the present invention will be disclosed in detail in the following specific embodiments and drawings.

Description of the Drawings

[0031] The invention will be further described below with reference to the drawings:

[0032] Figure 1 It is the preparation flow chart of the iron-manganese composite-based porous polyurethane cement sponge filler of the present invention;

[0033] Figure 2 It is the SEM image of the surface morphology of the polyurethane sponge filler of the high-efficiency nitrogen-removing suspended filler prepared in Examples 1-4 of the present invention before river treatment. Among them, (a) to (d) are the SEM images of the biofilms formed on the polyurethane sponge surface in Examples 1-4 in sequence;

[0034] Figure 3 It is the microscopic examination image of the surface of the polyurethane sponge filler of the high-efficiency nitrogen-removing suspended filler prepared in Examples 1-4 of the present invention after being applied to river treatment. Among them, (a) to (d) are the microscopic examination images of the surface of the polyurethane sponge filler in Application Examples 1-4 in sequence;

[0035] Figure 4 It is the finished product sample diagram of the high-efficiency nitrogen-removing suspended filler prepared in Example 1 of the present invention;

[0036] Figure 5 It is the finished product sample diagram of the high-efficiency nitrogen-removing suspended filler prepared in Examples 1-4 of the present invention after being applied to river treatment. Among them, (a) to (d) are the finished product sample diagrams of the high-efficiency nitrogen-removing suspended filler in Application Examples 1-4 after being applied to river treatment in sequence;

[0037] Figure 6Gram staining diagrams of the high-efficiency nitrogen-removing suspended fillers prepared in Examples 1-4 of the present invention after being applied to river treatment. Among them, (a)-(d) are the gram staining diagrams of the high-efficiency nitrogen-removing suspended fillers in Application Examples 1-4 after being applied to river treatment in sequence;

[0038] Figure 7 Carbon release diagram of the high-efficiency nitrogen-removing suspended filler prepared in Example 2 of the present invention;

[0039] Figure 8 Ammonia nitrogen data diagrams of the high-efficiency nitrogen-removing suspended fillers prepared in Examples 1-4 of the present invention after being applied to river treatment. Among them, (a)-(d) are the ammonia nitrogen data diagrams of the high-efficiency nitrogen-removing suspended fillers in Application Examples 1-4 after being applied to river treatment in sequence;

[0040] Figure 9 Total nitrogen data diagrams of the high-efficiency nitrogen-removing suspended fillers prepared in Examples 1-4 of the present invention after being applied to river treatment. Among them, (a)-(d) are the total nitrogen data diagrams of the high-efficiency nitrogen-removing suspended fillers in Application Examples 1-4 after being applied to river treatment in sequence.

Specific Embodiments

[0041] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings of the embodiments of the present invention. However, the following embodiments are only the preferred embodiments of the present invention, not all of them. Based on the embodiments in the embodiments, other embodiments obtained by those skilled in the art without creative efforts all fall within the protection scope of the present invention.

[0042] Those skilled in the art can understand that, without conflict, the features in the following embodiments and embodiments can be combined with each other.

[0043] The embodiments of the present invention provide a high-efficiency nitrogen-removing suspended filler for river treatment and a preparation method thereof. The preparation method includes the following steps:

[0044] A composite biochar mixed filler is made by mixing sludge-based biochar and PHBV;

[0045] The composite biochar mixed filler is loaded onto the surface of a polyurethane sponge to form a modified polyurethane sponge;

[0046] The modified polyurethane sponge is placed in a bioreactor for reaction, and finally a nitrogen-removing suspended filler with a biofilm attached inside is obtained.

[0047] Preferably, the preparation method of the sludge-based biochar is as follows: First, the excess sludge after domestic wastewater treatment in the sewage treatment plant is naturally air-dried or heated and dried; then it is mechanically crushed and sieved to obtain the sludge raw materials for the sludge-based biochar; then the raw materials of the sludge-based biochar, including sludge, diatomite, iron powder and starch, are mechanically mixed and pyrolyzed at high temperature, and after cooling, it is milled and sieved again to obtain the sludge-based biochar.

[0048] Using the preparation method of the high-efficiency denitrifying suspended filler described above, a high-efficiency denitrifying suspended filler for river regulation is prepared.

[0049] In the present invention, by using a polyurethane sponge with a large specific surface area as a carrier, a suitable microbial growth environment is provided, which is conducive to the rapid formation of biofilms; among them, the sludge-based biochar can immobilize microorganisms on the activated carbon, improve the adsorption capacity of the activated carbon, extend the service life of the activated carbon, and enhance the degradation ability of organic substances in water. The PHBV (3-hydroxybutyric acid-co-3-hydroxyvaleric acid ester) in the filler can be hydrolyzed to generate soluble small-molecule substances under the action of microbial extracellular enzymes, and these substances participate in the denitrification process as the carbon source and electron donor of microorganisms, and can provide sufficient carbon for the biofilm in the oligotrophic river water body, providing conditions for the rapid growth of microorganisms, thus promoting water purification effects such as denitrification, truly realizing the synergistic effect of organic biodegradable polymers and inorganic substances. In addition, the added iron powder has excellent nitrogen adsorption performance, can effectively remove nitrogen elements in river water and increase the microbial activity in the biofilm. The sludge-based biochar and iron powder act together to enhance the indirect denitrification function of iron elements.

[0050] The specific technical solution of the present invention is as follows:

[0051] A preparation method of a high-efficiency denitrifying suspended filler for river regulation, the steps are as follows:

[0052] Step 1: Preparation of sludge-based biochar

[0053] First, the excess sludge after domestic wastewater treatment in the sewage treatment plant is naturally air-dried. The dried sludge is mechanically crushed and sieved through a 100-150 mesh sieve for standby.

[0054] The ratio of each raw material of the sludge-based biochar is: 65%-75% sludge, 13%-20% diatomite, 7.5%-10% iron powder and 5%-8.5% starch. The raw materials are mechanically mixed and pyrolyzed in a muffle furnace at 450-600 °C for 30-50 min, and after cooling, it is milled and sieved through a 100 mesh sieve to obtain the sludge-based biochar.

[0055] Step 2: Preparation of composite biochar mixed filler

[0056] Add a certain mass of sludge-based biochar and PHBV (mass ratio 3:1) obtained in Step 1 to an appropriate amount of deionized water, stir evenly, place in an ultrasonic cleaner and ultrasonicate for 1 - 3 h with an ultrasonic power of 250 - 350 W. After ultrasonication, let it cool and stand for 10 - 14 h to obtain a composite biochar mixed filler for standby.

[0057] Step 3: Modification of polyurethane sponge

[0058] Load the composite biochar mixed filler obtained in Step 2 onto the surface of the polyurethane sponge using a 1.5 - 2.5% sodium alginate aqueous solution and a 1.5 - 2.8% polyvinyl alcohol aqueous solution as binders. Successful loading is observed when the sponge surface is evenly covered with particles and not washed away by water, thus completing the modification of the polyurethane sponge.

[0059] Step 4: Formation of biofilm

[0060] Place the modified polyurethane sponge obtained in Step 3 in a reactor, which is a reactor with stable operation in the laboratory. After 11 - 20 days of enrichment, domestication, and biofilm attachment, finally fish it out to obtain a highly efficient denitrifying suspended filler for river treatment with a large amount of biofilm attached inside.

[0061] A highly efficient denitrifying suspended filler for river treatment is prepared by using the described preparation method of the highly efficient denitrifying suspended filler. The suspended filler of the present invention can be used to remove nitrogen-containing pollutants in rivers. Among them, PHBV (3-hydroxybutyric acid-co-3-hydroxyvaleric acid ester) in the filler can be hydrolyzed into soluble small molecules under the action of microbial extracellular enzymes, and these substances participate in the denitrification process as the carbon source and electron donor of microorganisms, thus promoting water purification effects such as denitrification.

[0062] In the present invention, the composite biochar mixed filler and PHBV are compounded by ultrasonication, thereby improving their water solubility, reaction activity, adsorption performance, and biological activity, enabling rapid enrichment of the microbial biofilm amount, making the modified filler capable of interacting with target pollutants more efficiently, and enhancing the purification ability of the filler. The filler of the present invention provides a suitable microenvironment, which is conducive to the enrichment of microorganisms related to denitrification (such as nitrifying bacteria). The porous structure and hydrophilic surface of the filler provide good attachment points for microorganisms, promoting the formation of biofilm and showing higher purification efficiency when treating river water.

[0063] By surface loading the composite biochar mixed filler, this filler is conducive to the rapid formation of biofilm and the carried PHBV has the function of promoting the activity of microbial denitrification-related enzymes, thereby improving the denitrification effect. The present invention can flexibly adjust the proportion of the composite biochar mixed filler and PHBV according to different water quality conditions, and can perform highly efficient denitrification in rivers with different pollution situations.

[0064] In the technical solution of the present invention, the filler will not degrade when soaked in wastewater for a long time, nor will it be toxic to microorganisms. Compared with other materials such as polyvinyl chloride, the filler has better chemical corrosion resistance and biocompatibility, and can maintain stable performance in complex environments, ensuring the long-term use effect of the filler.

[0065] The filler of the present invention can provide a good growth environment for microorganisms. The microorganisms have high activity on the filler and can rapidly degrade organic matter and other pollutants in the wastewater, further improving the water purification effect.

[0066] Example 1:

[0067] 1) The excess sludge from a sewage treatment plant in Hangzhou, Zhejiang was naturally air-dried. The dried sludge was mechanically pulverized and passed through a 100-mesh sieve for standby. The ratio of the raw materials of the sludge-based biochar was: 65% sludge, 20% diatomite, 10% iron powder, and 5% starch. After the raw materials were mechanically mixed, they were pyrolyzed at 550 °C in a muffle furnace for 45 min, cooled and then ground through a 100-mesh sieve to obtain the sludge-based biochar.

[0068] 2) A certain mass of the sludge-based biochar obtained in step 1 and PHBV (mass ratio 3:1) were added with an appropriate amount of deionized water and stirred evenly, placed in an ultrasonic cleaner and ultrasonically treated for 2 h with an ultrasonic power of 300 W. After the ultrasonic treatment, it was left to cool for standby, and left standing for 10 h to obtain the composite biochar mixed filler.

[0069] 3) The composite biochar mixed filler obtained in step 2 was loaded onto the surface of the polyurethane sponge using a 1.5% sodium alginate aqueous solution and a 2% polyvinyl alcohol aqueous solution as adhesives. When it was observed that the surface of the sponge was evenly covered with particles and not washed away by water, the loading was successful, and the modification of the polyurethane sponge was completed.

[0070] 4) The modified polyurethane sponge obtained in step 3 was placed in a reactor, which was a reactor with stable operation in the laboratory. After 15 days of enrichment, domestication, and biofilm formation, it was finally fished out to obtain a highly efficient denitrifying suspended filler for river treatment with a large amount of biofilm attached inside.

[0071] Example 2:

[0072] 1) The excess sludge from a sewage treatment plant in Haining, Zhejiang for treating domestic sewage was naturally air-dried. The dried sludge was mechanically pulverized and passed through a 100-mesh sieve for standby. The ratio of the raw materials of the sludge-based biochar was: 65% sludge, 20% diatomite, 10% iron powder, and 5% starch. After the raw materials were mechanically mixed, they were pyrolyzed at 550 °C in a muffle furnace for 45 min, cooled and then ground through a 100-mesh sieve to obtain the sludge-based biochar.

[0073] 2) Add a certain mass of sludge-based biochar and PHBV obtained in step 1 (mass ratio 3:1), add an appropriate amount of deionized water, stir evenly, place it in an ultrasonic cleaner and sonicate for 2 h with an ultrasonic power of 310 W. After sonication, let it cool and set aside. Let it stand for 12 h to obtain a composite biochar mixed filler.

[0074] 3) Load the composite biochar mixed filler obtained in step 2 onto the surface of a polyurethane sponge using a 1.9% sodium alginate aqueous solution and a 2.2% polyvinyl alcohol aqueous solution as binders. If it is observed that the surface of the sponge is evenly covered with particles and is not washed away by water, the loading is successful, and the modification of the polyurethane sponge is completed.

[0075] 4) Place the modified polyurethane sponge obtained in step 3 in a reactor, which is a reactor with stable operation in the laboratory. After 14 days of enrichment, domestication, and biofilm formation, finally fish it out to obtain a highly efficient denitrifying suspended filler for river treatment with a large amount of biofilm attached inside.

[0076] Example 3:

[0077] 1) Naturally air-dry the excess sludge from a sewage treatment plant in Hangzhou, Zhejiang, which treats domestic sewage. After drying, mechanically crush the sludge and pass it through a 100-mesh sieve, and set it aside. The raw material ratio of the sludge-based biochar is: 65% sludge, 20% diatomite, 10% iron powder, and 5% starch. After mechanically mixing the raw materials, pyrolyze them at 550 °C in a muffle furnace for 50 min. After cooling, grind it again and pass it through a 100-mesh sieve to obtain the sludge-based biochar.

[0078] 2) Add a certain mass of sludge-based biochar and PHBV obtained in step 1 (mass ratio 3:1), add an appropriate amount of deionized water, stir evenly, place it in an ultrasonic cleaner and sonicate for 1.5 h with an ultrasonic power of 300 W. After sonication, let it cool and set aside. Let it stand for 13 h to obtain a composite biochar mixed filler.

[0079] 3) Load the composite biochar mixed filler obtained in step 2 onto the surface of a polyurethane sponge using a 2% sodium alginate aqueous solution and a 1.7% polyvinyl alcohol aqueous solution as binders. If it is observed that the surface of the sponge is evenly covered with particles and is not washed away by water, the loading is successful, and the modification of the polyurethane sponge is completed.

[0080] 4) Place the modified polyurethane sponge obtained in step 3 in a reactor, which is a reactor with stable operation in the laboratory. After 13 days of enrichment, domestication, and biofilm formation, finally fish it out to obtain a highly efficient denitrifying suspended filler for river treatment with a large amount of biofilm attached inside.

[0081] Experimental Example 4

[0082] 1) The excess sludge from a sewage treatment plant in Haining, Zhejiang, which treats domestic sewage, is naturally air-dried. The dried sludge is mechanically pulverized and sieved through a 100-mesh sieve for standby. The raw material ratio of sludge-based biochar is: 65% sludge, 20% diatomite, 10% iron powder, and 5% starch. After mechanical mixing of the raw materials, they are pyrolyzed at 550 °C in a muffle furnace for 45 min, cooled, and then milled and sieved through a 100-mesh sieve to obtain sludge-based biochar.

[0083] 2) A certain mass of the sludge-based biochar obtained in step 1 and PHBV (mass ratio 3:1) are added with an appropriate amount of deionized water, stirred evenly, placed in an ultrasonic cleaner and ultrasonically treated for 2 h with an ultrasonic power of 310 W. After the ultrasonic treatment, it is left to cool for standby, and left standing for 12 h to obtain a composite biochar mixed filler.

[0084] 3) The composite biochar mixed filler obtained in step 2 is loaded onto the surface of a polyurethane sponge using a 1.9% sodium alginate aqueous solution and a 2.2% polyvinyl alcohol aqueous solution as binders. When it is observed that the surface of the sponge is evenly covered with particles and is not washed away by water, the loading is successful, and the modification of the polyurethane sponge is completed.

[0085] 4) The modified polyurethane sponge obtained in step 3 is placed in a reactor, which is a reactor with stable operation in the laboratory. After 14 days of enrichment, domestication, and biofilm formation, it is finally fished out to obtain a highly efficient denitrifying suspended filler for river treatment with a large amount of biofilm attached inside.

[0086] Application Example 1

[0087] Examine the morphological changes of the biofilm on the surface of the polyurethane sponge of the highly efficient denitrifying suspended filler for river treatment prepared in Example 1 and the denitrification data after river treatment.

[0088] One parallel laboratory-scale stainless steel biofilm reactor was established, and the effective volume of the reactor was 2.2 m 3 . The reactor was filled with the highly efficient denitrifying suspended filler prepared in Example 1. The reactor was operated for 30 days. During the operation of the reactor, the dissolved oxygen concentration in the reactor was maintained at 7 - 9 mg / L. The reactor temperature was adjusted to 25 ± 0.5 °C, the reactor water was river water, the total nitrogen concentration was 8 mg / L, and the total phosphorus concentration was 3 mg / L.

[0089] Application Example 2

[0090] Examine the morphological changes of the biofilm on the surface of the polyurethane sponge of the highly efficient denitrifying suspended filler for river treatment prepared in Example 2 and the denitrification data after river treatment.

[0091] One parallel laboratory-scale stainless steel biofilm reactor was established, and the effective volume of the reactor was 2 m 3。The reactor was filled with the highly efficient denitrifying suspended packing prepared in Example 2. The reactor was operated for 30 days. During the operation of the reactor, the dissolved oxygen concentration in the reactor was maintained at 7-9 mg / L. The reactor temperature was adjusted to 32±0.5 °C. The water used in the reactor was river water, with a total nitrogen concentration of 7 mg / L and a total phosphorus concentration of 2.5 mg / L.

[0092] Application Example 3

[0093] Examine the morphological changes of the biofilm on the surface of the polyurethane sponge of the highly efficient denitrifying suspended packing prepared in Example 3 for river regulation and the denitrification data after river regulation.

[0094] One parallel laboratory-scale stainless steel biofilm reactor was established, and the effective volume of the reactor was 2 m 3 。The reactor was filled with the highly efficient denitrifying suspended packing prepared in Example 3. The reactor was operated for 30 days. During the operation of the reactor, the dissolved oxygen concentration in the reactor was maintained at 7-9 mg / L. The reactor temperature was adjusted to 28±0.5 °C. The water used in the reactor was river water, with a total nitrogen concentration of 5 mg / L and a total phosphorus concentration of 5 mg / L.

[0095] Application Example 4

[0096] Examine the morphological changes of the biofilm on the surface of the polyurethane sponge of the highly efficient denitrifying suspended packing prepared in Example 4 for river regulation and the denitrification data after river regulation.

[0097] One parallel laboratory-scale stainless steel biofilm reactor was established, and the effective volume of the reactor was 2 m 3 。The reactor was filled with the highly efficient denitrifying suspended packing prepared in Example 4. The reactor was operated for 30 days. During the operation of the reactor, the dissolved oxygen concentration in the reactor was maintained at 7-9 mg / L. The reactor temperature was adjusted to 26±0.5 °C. The water used in the reactor was river water, with a total nitrogen concentration of 10 mg / L and a total phosphorus concentration of 2.2 mg / L.

[0098] After adding the highly efficient denitrifying suspended packing for river regulation, the denitrification efficiency was significantly improved during river regulation; the denitrification efficiency of the prepared highly efficient denitrifying suspended packing for river regulation increased with the increase of the operation time. Although the ordinary polyurethane sponge packing has a certain effect on strengthening the denitrification reaction after being put in, there is an obvious gap compared with the highly efficient denitrifying suspended packing for river regulation prepared by modification.

[0099] As described above, it is only the specific implementation manner of the invention, but the protection scope of the invention is not limited thereto. Those skilled in the art should understand that the invention includes but is not limited to the content described in the drawings and the above specific implementation manner. Any modification that does not deviate from the functional and structural principles of the invention will be included in the scope of the claims.

Claims

1. A preparation method of an efficient denitrifying suspended filler for river regulation, characterized in that It includes the following steps: A composite biochar mixed filler is made by mixing sludge-based biochar and PHBV; The composite biochar mixed filler is loaded onto the surface of a polyurethane sponge to form a modified polyurethane sponge; The modified polyurethane sponge is placed in a bioreactor for reaction, and finally a denitrifying suspended filler with a biofilm attached inside is obtained.

2. The preparation method of the high-efficiency denitrification suspended packing according to claim 1, characterized in that, The preparation method of the sludge-based biochar is as follows: First, the excess sludge after domestic wastewater treatment in a sewage treatment plant is naturally air-dried or heated and dried; then it is mechanically crushed and sieved to obtain the sludge raw materials of the sludge-based biochar; then the raw materials of the sludge-based biochar, including sludge, diatomite, iron powder and starch, are mechanically mixed and pyrolyzed at high temperature, cooled and then ground and sieved to obtain the sludge-based biochar.

3. The preparation method of the high-efficiency denitrification suspended packing according to claim 2, wherein The mass ratio of each raw material of the sludge-based biochar is: 65%-75% sludge, 13%-20% diatomite, 7%-10% iron powder and 5%-8.5% starch.

4. The preparation method of the high-efficiency denitrification suspended packing according to claim 2, characterized in that The process of high-temperature pyrolysis is: pyrolysis in a muffle furnace at 450-600°C for 30-50 min; and / or, after cooling, it is ground and sieved to obtain the sludge-based biochar.

5. The preparation method of the high-efficiency denitrification suspension packing according to claim 1, characterized in that The preparation method of the composite biochar mixed filler is: The sludge-based biochar and PHBV are configured according to a set mass ratio, deionized water is added and stirred evenly; then it is placed in an ultrasonic cleaner for ultrasonic treatment; after the ultrasonic treatment ends, it is left to cool; finally, it is left standing for a set time to obtain the composite biochar mixed filler.

6. The preparation method of the high-efficiency denitrification suspension filler according to claim 5, wherein, The mass ratio of the sludge-based biochar to PHBV is 2-8:1; and / or, it is ultrasonically treated in an ultrasonic cleaner for 1-3 h, and the ultrasonic power is 250-350 W; and / or, the composite biochar mixed filler is obtained by standing for 10-14 h.

7. The preparation method of the high-efficiency denitrification suspension packing according to claim 1, characterized in that, The modification method of the polyurethane sponge is: The composite biochar mixed filler is loaded onto the surface of the polyurethane sponge by using an adhesive.

8. The preparation method of the high-efficiency denitrification suspension packing according to claim 7, characterized in that, The adhesive is made by mixing an aqueous solution of sodium alginate at 1.5-2.5% and an aqueous solution of polyvinyl alcohol at 1.5-2.8%.

9. The preparation method of the high-efficiency denitrification suspended packing according to claim 1, characterized in that, In the bioreactor, the modified polyurethane sponge is enriched, domesticated and biofilm-attached for 11-20 days, and finally fished out to obtain a highly efficient denitrifying suspended filler with a large amount of biofilm attached inside for river regulation.

10. An efficient denitrifying suspended filler used for river regulation, characterized in that, It is prepared by using the preparation method of the highly efficient denitrifying suspended filler described in any one of claims 1 to 9.

Images