Preparation method and application of efficient polyculture denitrification synergistic phosphorus removal filler

Abstract

The invention discloses a preparation method and application of efficient polyculture denitrification synergistic phosphorus removal filler, and belongs to the field of functional material development and sewage treatment. The method specifically comprises the following steps: step 1, uniformly mixing iron ore powder, sulfur powder and polyester high-molecular compound powder, and heating and melting; and 2, carrying out molding treatment on the molten substance, and cooling and solidifying to obtain the efficient polyculture denitrification synergistic phosphorus removal filler. According to the polyculture denitrification synergistic phosphorus removal filler disclosed by the invention, a polyester high-molecular compound is used as a supplementary electron donor of a sulfur-iron ore autotrophic denitrification synergistic phosphorus removal system, so that the nitrogen removal efficiency of denitrification is improved; the compound also can be used as an electron donor to participate in a ferrous sulfide reduction reaction, so that the discharge of sulfate in effluent is reduced, and enhanced phosphorus is removed in a form of Fe3 (PO4) 2 precipitate; meanwhile, heterotrophic denitrification generates alkalinity to make up the consumption of alkalinity in the autotrophic denitrification process, and the stability of pH in the system is maintained, so that the removal efficiency of nitrogen and phosphorus is enhanced, and secondary pollution is reduced.

Description

Technical Field

[0001] The invention belongs to the field of functional material development and sewage treatment, and specifically relates to a preparation method and application of a high-efficiency polyculture denitrification synergistic phosphorus removal filler. Background Art

[0002] Nitrogen and phosphorus are the main factors leading to eutrophication of water bodies, and their control is crucial to the protection of urban water environment. Improving the nitrogen and phosphorus treatment efficiency of urban sewage treatment plants is the key to improving eutrophication of water bodies. Urban sewage treatment plants generally use primary physical treatment and secondary biological treatment technologies. The effluent after secondary treatment is the secondary effluent. At present, many sewage treatment plants use the "coagulation-sedimentation-filtration" process to deeply treat the secondary effluent to meet the increasingly stringent total nitrogen and total phosphorus emission standards, which significantly increases investment and operating costs. If the filtration unit of the "coagulation-sedimentation-filtration" process can be transformed to have the ability to deeply remove nitrogen and phosphorus, it will help meet strict emission standards and reduce costs.

[0003] The sulfur-iron ore co-substrate autotrophic denitrification process is widely used in sewage deep treatment because it has the advantages of coordinated nitrogen and phosphorus removal and low cost due to the coupling of biological autotrophic denitrification and chemical phosphorus removal. However, the sulfur-iron ore co-substrate autotrophic denitrification process has the problem of long hydraulic retention time (HRT) due to the slow release of autotrophic denitrification electron donors and the slow growth rate of autotrophic denitrifying bacteria. At the same time, there is a problem of sulfate (SO 4 2- ) accumulation and alkalinity consumption and other secondary pollution problems.

[0004] The introduction of organic carbon into the sulfur-iron ore co-substrate autotrophic denitrification process will increase the electron donor for nitrate denitrification, thereby compensating for the low denitrification efficiency caused by insufficient electron donors in the sulfur-iron ore co-substrate autotrophic denitrification process. At the same time, it will stimulate the proliferation of heterotrophic denitrifiers and facultative autotrophic denitrifiers, promote the formation of biofilms, and achieve the purpose of improving denitrification efficiency and reducing HRT. At the same time, microorganisms can use organic carbon as an electron donor for sulfate reduction, thereby reducing the SO produced by sulfur autotrophic denitrification. 4 2- The accumulation of phosphorus and Fe 3 (PO 4 ) 2 Alkalinity is removed in the form of precipitation. Autotrophic denitrification consumes alkalinity, while heterotrophic denitrification produces alkalinity. The introduction of organic carbon helps to maintain neutral conditions in the system. Therefore, the mixed denitrification system that couples autotrophic denitrification and heterotrophic denitrification has received great attention in recent years.

[0005] At present, the organic carbon introduced by the polyculture denitrification synergistic phosphorus removal system is mainly liquid carbon sources such as methanol and ethanol or agricultural wastes such as corn stalks and grapefruit peels. However, the existing methods have the problems of difficult to accurately add liquid carbon sources, unstable electron release rate of solid carbon sources, and frequent replacement, and unavoidable secondary pollution. Therefore, there is an urgent need for a polyculture denitrification synergistic phosphorus removal filler product with high nitrogen and phosphorus removal efficiency, complete bioavailability, and no secondary pollution. Summary of the invention

[0006] In order to improve the efficiency of simultaneous nitrogen and phosphorus removal in secondary effluent deep treatment, increase material utilization, and reduce secondary pollution, the present invention provides a preparation method and application of a high-efficiency polyculture denitrification synergistic phosphorus removal filler.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for preparing a highly efficient polyculture denitrification synergistic phosphorus removal filler comprises the following steps:

[0009] Step 1: mixing iron ore powder, sulfur powder and polyester polymer powder until the mixture is uniform in color, which means it is uniformly mixed; heating the uniformly mixed mixture and continuously stirring it during the heating process until the color of the mixture becomes uniform again, at which time a molten material is obtained;

[0010] Step 2: shaping the above molten material, and cooling and solidifying it at room temperature to obtain a high-efficiency mixed culture denitrification synergistic phosphorus removal filler.

[0011] Furthermore, in step 1, the raw material is subjected to foaming treatment during the heating and melting process. The foaming method includes one or more of surfactant foaming and chemical foaming; the surfactant foaming agent used in the surfactant foaming includes one or more of sodium dodecyl sulfate, sodium polyoxyethylene fatty alcohol ether sulfate, rosin soap foaming agent, animal and plant protein foaming agent, and pulp waste liquid; the chemical foaming agent used in the chemical foaming includes one or more of azodicarbonamide, sodium bicarbonate, and 4,4'-oxybisbenzenesulfonyl hydrazide; the amount of the surfactant foaming agent / chemical foaming agent used is 0-10% of the total amount of the raw material components.

[0012] Furthermore, the volume ratio of the sulfur powder, the iron ore powder and the polyester polymer compound powder is controlled within the range of (10%-50%): (20%-70%): (20%-70%).

[0013] Furthermore, the iron ore includes a combination of one or more of pyrite, pyrrhotite, magnetite, hematite, ilmenite, hematite, limonite and siderite.

[0014] Furthermore, the polyester polymer compound includes one or more combinations of polyhydroxyalkanoates, polycaprolactone, polylactic acid, polyhydroxybutyrate, polyhydroxyalkanoates, and polybutylene succinate.

[0015] Furthermore, the heating and melting temperature is 100-250°C.

[0016] Furthermore, the molding treatment includes die molding, extrusion granulation, stirring granulation or crushing granulation.

[0017] An application of the filler prepared by the preparation method, wherein the high-efficiency polyculture denitrification synergistic phosphorus removal filler is used for denitrification and phosphorus removal in sewage.

[0018] Furthermore, the sewage includes deep treatment of surface runoff, domestic sewage, commercial sewage, industrial sewage and their secondary treatment effluents to achieve simultaneous removal of nitrogen and phosphorus.

[0019] Furthermore, the sewage is sewage containing nitrates and phosphates.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention utilizes polyester polymer compounds that have stable organic matter release efficiency and can be completely degraded by microorganisms as a solid phase slow-release carbon source, mixes with sulfur powder, iron ore powder and foaming material, heats and melts, and then cools and solidifies to prepare a highly efficient polyculture denitrification synergistic phosphorus removal filler for secondary effluent deep treatment. The polyculture denitrification synergistic phosphorus removal filler uses polyester polymer compounds as a supplementary electron donor for the sulfur-iron ore autotrophic denitrification synergistic phosphorus removal system to improve the denitrification efficiency; it can also participate in the sulfur-iron reduction reaction as an electron donor, reduce the discharge of effluent sulfate, and strengthen the phosphorus to Fe 3 (PO 4 ) 2 At the same time, heterotrophic denitrification produces alkalinity to make up for the consumption of alkalinity in the autotrophic denitrification process, maintaining the stability of pH in the system, thereby enhancing the removal efficiency of nitrogen and phosphorus and reducing secondary pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the denitrification and phosphorus removal process of the high-efficiency polyculture denitrification synergistic phosphorus removal filler of the present invention;

[0023] Figure 2 It is the total nitrogen removal effect diagram in Example 1;

[0024] Figure 3 This is a diagram showing the total phosphorus removal effect in Example 1. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] The main components of the polyculture denitrification synergistic phosphorus removal filler for secondary effluent deep treatment described in the present invention are iron ore, sulfur and polyester polymer compounds, as well as a pore-forming agent for foaming. Figure 1 As shown in the figure: When the filler is put into the sewage to be treated, the autotrophic denitrifying bacteria use the sulfur in the filler as an electron donor to convert NO 3 - Restore to N 2 , sulfur is oxidized to sulfate (SO 4 2- ) and generate hydrogen ions (H + ), as shown in formula (1); at the same time, autotrophic denitrifying bacteria use iron ore as an electron donor to convert NO 3 - Restore to N 2 , ferrous ions (Fe 2+ ) is oxidized to iron ions (Fe 3+ ), while consuming hydrogen ions (H + ), as shown in formula (2); heterotrophic denitrifying bacteria use polyester polymer compounds as electron donors to convert NO 3 - Restore to N 2 , polyester polymer compounds are oxidized to bicarbonate (HCO 3 - ), as shown in formula (3). HCO produced by heterotrophic denitrification 3 - The H produced by autotrophic denitrification + The reaction generates H 2 O and CO 2 , which helps to maintain the stability of pH in the system, as shown in formula (4). At the same time, the soluble organic matter (in the form of CH 2 O) can serve as an electron donor for sulfate-reducing bacteria to convert SO 4 2- Reduction to sulfide (S 2- ), as shown in formula (5); it can also serve as an electron donor for iron-reducing bacteria to convert Fe 3+ Reduction to Fe 2+ , as shown in formula (6); the restored S 2- and Fe 2+It can be used as an electron donor for autotrophic denitrification reaction, thus realizing the sulfide iron cycle reaction. 2+ Can be with PO 4 3- -P reaction, generating FePO 4 Fe with a smaller solubility product 3 (PO 4 ) 2 , strengthen PO 4 3- -P, as shown in formula (7).

[0027]

[0028]

[0029] CH 2 O+4Fe 3+ +H 2 O→4Fe 2+ +4H + +CO 2 Formula (6)

[0030]

[0031] Embodiment 1:

[0032] A preparation method and application of an autotrophic denitrification synergistic phosphorus removal functional material for secondary effluent deep treatment, comprising the following steps:

[0033] (1) Prepare raw materials: Mix 2 L of pyrite powder, 1 L of sulfur powder, and 1.5 L of polyhydroxyalkanoate powder (passed through a 100-mesh sieve) evenly.

[0034] (2) Place the mixed raw materials in an oil bath and set the heating temperature to 200 degrees Celsius. During the heating process, continue stirring until the mixture is completely dissolved and the color is uniform, and ensure that there are no obvious large particles.

[0035] (3) pouring the dissolved mixture into a spherical silica gel mold for molding, and then cooling and solidifying it at room temperature to finally obtain a highly efficient polyculture denitrification synergistic phosphorus removal filler.

[0036] (4) The above-mentioned high-efficiency mixed culture denitrification synergistic phosphorus removal filler was placed in an upflow filter to treat the secondary effluent. The hydraulic retention time was set to 1 hour. After the reactor was running stably, the total nitrogen and total phosphorus removal effects of the effluent were tested. The experimental results showed that the average removal rate of total nitrogen was 94.96%, and the average removal rate of total phosphorus was 75.03%. Figure 2 and 3The total nitrogen and total phosphorus concentrations in the effluent meet the "Surface Water Environmental Quality Standard" (GB3838-2003)

[0037] Class IV water standards in.

[0038] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing a highly efficient polyculture denitrification synergistic phosphorus removal filler, characterized in that: The following steps are involved: Step 1, mixing iron ore powder, sulfur powder and polyester polymer compound powder uniformly and heating to melt; Step 2: shaping the molten material, cooling and solidifying it to obtain a highly efficient polyculture denitrification synergistic phosphorus removal filler.

2. The preparation method according to claim 1, characterized in that: The volume ratio of the sulfur powder, the iron ore powder and the polyester polymer compound powder is controlled within the range of (10%-50%): (20%-70%): (20%-70%).

3. The preparation method according to claim 1, characterized in that: In step 1, the raw materials are foamed during the heating and melting process.

4. The preparation method according to claim 1, characterized in that: The iron ore includes one or more combinations of pyrite, pyrrhotite, magnetite, hematite, ilmenite, hematite, limonite and siderite.

5. The preparation method according to claim 1, characterized in that: The polyester polymer compound includes one or more combinations of polyhydroxyalkanoates, polycaprolactone, polylactic acid, polyhydroxybutyrate, polyhydroxyalkanoates, and polybutylene succinate.

6. The preparation method according to claim 1, characterized in that: The heating and melting temperature is 100-250°C.

7. The preparation method according to claim 1, characterized in that: The molding treatment methods include die molding, extrusion granulation, stirring granulation or crushing granulation.

8. An application of a filler prepared by the preparation method according to any one of claims 1 to 7, characterized in that: The high-efficiency polyculture denitrification synergistic phosphorus removal filler is used for denitrification and phosphorus removal in sewage.

9. The use according to claim 8, characterized in that: The sewage includes surface runoff, domestic sewage, commercial sewage, industrial sewage and their secondary treated effluents.

10. The use according to claim 8, characterized in that: The sewage is sewage containing nitrates and phosphates.

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