Desulfurized ash-based denitrification nitrogen removal filter material as well as preparation method and application thereof
By using desulfurized ash-based denitrification filter media, combined with the synergistic effect of sulfur and desulfurized ash, the problems of slow biochemical reaction start-up, high effluent acidity, and high cost of sulfur autotrophic denitrification filter media have been solved, achieving efficient and stable denitrification effect and cost reduction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-23
- Publication Date
- 2026-04-10
AI Technical Summary
Existing sulfur-based autotrophic denitrification filter media suffer from problems such as slow biochemical reaction start-up, high effluent acidity, filter media accumulation and pulverization, and high cost during the denitrification process. In addition, sulfur is expensive and it is difficult to efficiently treat industrial nitrogen-containing wastewater.
The desulfurization ash-based denitrification filter material utilizes sulfur electron donor materials as the main active component, combined with calcium carbonate and CaSO3 and calcium hydroxide in the desulfurization ash to neutralize the acidic environment, provide an inorganic carbon source, enhance the redox reaction, reduce costs, and improve denitrification efficiency.
It achieves efficient and stable denitrification reaction, stabilizes effluent pH, reduces production costs, and increases denitrification efficiency by 20%-50%. It is suitable for treating wastewater containing nitrate nitrogen of different concentrations and solves the shortcomings of existing technologies.
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Figure CN121823797A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of denitrification filter material, and particularly relates to a desulfurized fly ash-based denitrification filter material and a preparation method and application thereof. BACKGROUND
[0002] Nitrogen is a key nutrient element for the growth of algae. If industrial wastewater containing nitrogen is directly discharged without effective treatment, the excessive nitrogen content in natural water bodies will lead to eutrophication and acidification of the water bodies, causing serious harm to the ecological environment and human health. Eutrophication of water bodies can cause an outbreak of blue-green algae, consume dissolved oxygen in the water body, and produce algal toxins, which harm the growth and survival of aquatic plants and animals, leading to the death of a large number of aquatic plants and animals, causing a pungent smell in the regional environment, a decline in visual perception, and a serious impact on urban water supply safety. Excessive nitrate in drinking water can adversely affect human health and increase the risk of serious diseases, such as infantile methemoglobinemia, non-Hodgkin's lymphoma, and heart disease. Therefore, there are strict requirements for the emission concentration of nitrogen and phosphorus elements, which are the main influencing factors of eutrophication, in the effluent from sewage treatment plants, and the water quality indicators for discharge into natural water bodies are also constantly improving.
[0003] Biological denitrification has the advantages of low economic benefit, high treatment efficiency, no secondary pollution, and strong compatibility compared to traditional physical denitrification and chemical denitrification. Sulfur autotrophic denitrification is a method of biological denitrification, which can be carried out under anoxic or anaerobic conditions. Inorganic phototrophic or chemotrophic sulfur-oxidizing bacteria use S 2－ , S, Fe, H as electron donors to reduce nitrate as an electron acceptor, obtain energy through redox reaction, reduce nitrate to nitrogen, and achieve the process of autotrophic denitrification, thereby achieving the purpose of removing nitrate nitrogen. This technology has become a research hotspot in the field of denitrification due to its advantages of no need to add carbon source, low cost, no secondary pollution, and less sludge production.
[0004] Among the many electron donors, sulfur is widely used in autotrophic denitrification systems due to its wide source, easy processing, and other advantages. Liquid sulfur or chemical sulfur is usually high-temperature melted and then broken and sieved after cold cutting, or directly granulated underwater to obtain denitrification filter material. However, the pure sulfur autotrophic denitrification filter material has the following problems in the denitrification process: 1) slow start of biochemical reaction, which often takes 1-2 weeks to achieve the desired denitrification effect; 2) a large amount of H + is produced during the autotrophic denitrification process, which causes the effluent to be too acidic, making it difficult to meet water quality standards, and the acidic environment also inhibits the activity of denitrifying bacteria and other organisms, affecting subsequent biochemical reactions; 3) the stacking strength of single sulfur is not enough, causing the filter material to accumulate and powder in the denitrification module, affecting the denitrification effect; 4) sulfur is relatively expensive, and with the recent market supply and demand influence, the price of sulfur has risen to 4000 yuan / ton.
[0005] How to further improve the denitrification efficiency of sulfur-based autotrophic filter material and reduce the production cost of sulfur autotrophic denitrification filter material can become the focus of the industry.
[0006] Desulfurization ash is an industrial solid waste generated in the flue gas desulfurization process of coal-fired power plants, steel sintering, waste incineration, chemical industry and other industries. Desulfurization ash mainly includes calcium-based desulfurization ash, semi-dry desulfurization ash, magnesium-based desulfurization ash, magnesium-based desulfurization ash, sodium-based desulfurization ash and the like. Desulfurization ash, especially calcium-based desulfurization ash and semi-dry desulfurization ash, contains a large amount of unstable sulfite, which has poor chemical stability and is difficult to be directly used on a large scale in building materials, agriculture and chemical industry. Therefore, its resource utilization has become a bottleneck restricting the high-quality development of related industries. With the rapid development of the above industries, the amount of desulfurization ash generated in flue gas desulfurization is increasing day by day. How to dispose and high-value utilize the desulfurization ash generated in the above industries and realize the value of the industrial solid waste has become a major problem faced by the steel industry, power industry, chemical industry and other industries. SUMMARY
[0007] The present application provides a desulfurization ash-based autotrophic denitrification filter material, a preparation method and application thereof. The desulfurization ash-based autotrophic denitrification filter material uses sulfur electron donor material as the main active component. Calcium carbonate and CaSO3 and calcium hydroxide in the desulfurization ash have weak alkalinity, which is conducive to neutralizing the acid generated in the denitrification process, thereby ensuring the stability of the effluent pH value, providing a good environment for the biofilm formation of denitrifying microorganisms, and ensuring the efficient denitrification reaction. Calcium carbonate releases carbonate ions while neutralizing part of H+, which provides inorganic carbon source for denitrifying microorganisms. At the same time, the use of desulfurization ash instead of part of elemental sulfur significantly reduces the cost. The +4 valence sulfur contained in CaSO3 in the desulfurization ash and the 0 valence sulfur in sulfur have a synergistic effect, which effectively improves the redox reaction between NO3 - and H2S, thereby achieving excellent denitrification effect and realizing efficient denitrification reaction and waste treatment with waste.
[0008] Technical scheme: In order to achieve the above application purpose, the technical scheme adopted by the present application is as follows:
[0009] A desulfurization ash-based denitrification filter material, comprising the following raw materials by weight:
[0010] 150-255 parts by weight of sulfur, 1-55 parts by weight of calcium carbonate, and 1-55 parts by weight of desulfurization ash.
[0011] As a preferred scheme, the desulfurization ash-based denitrification filter material comprises the following raw materials by weight:
[0012] 195-210 parts by weight of elemental sulfur, 10-30 parts by weight of calcium carbonate, 10-45 parts by weight of desulfurization ash
[0013] As a preferred solution, the desulfurization ash-based denitrification denitration filter material comprises the following raw materials by weight:
[0014] 195-210 parts by weight of elemental sulfur, 15-30 parts by weight of calcium carbonate, 30-45 parts by weight of desulfurization ash.
[0015] As a specific embodiment, the elemental sulfur is solid sulfur or liquid sulfur, or a mixture of the two in any ratio.
[0016] As a specific embodiment, the calcium carbonate is one or a mixture of several of limestone, marble, calcite, aragonite, vaterite, dolomite, shells, pearls, corals, eggshells, and chalk.
[0017] As a specific embodiment, the desulfurization ash is one or a mixture of several of calcium-based desulfurization ash, semi-dry desulfurization ash, magnesium-based desulfurization ash, amino desulfurization ash, and sodium-based desulfurization ash.
[0018] The present application also provides a preparation method of the desulfurization ash-based denitrification denitration filter material, comprising the following steps:
[0019] S1: heating and stirring the solid elemental sulfur material to melt to obtain an active component melt, or mixing and heating the liquid elemental sulfur material to melt to obtain an active component melt, and maintaining the melting temperature; Desulfurized ash
[0020] S2: adding the desulfurization ash and calcium carbonate to the active component melt in sequence, or adding the calcium carbonate to the active component melt, and stirring until uniform to obtain a denitration filter mother liquor;
[0021] S3: cooling and forming the denitration filter mother liquor through a pore structure to obtain the desulfurization ash-based denitrification denitration filter material.
[0022] As a specific embodiment, in step S1, the melting temperature is 120-200℃; and in step S2, the temperature under stirring conditions is 120-200℃.
[0023] As a specific embodiment, in step S3, the diameter of the pore structure is 0.1-20 mm.
[0024] The present application finally provides the application of the desulfurization ash-based denitrification denitration filter material in denitration of wastewater containing nitrate nitrogen.
[0025] The desulfurization ash-based denitrification filter material provided by the present application contains a main active component, and the main active component mainly contains a sulfur-containing electron donor, such as sulfur and desulfurization ash, which can effectively reduce the production cost of the desulfurization ash-based denitrification filter material by replacing part of the sulfur with industrial solid waste desulfurization ash. - The +4 valence sulfur contained in CaSO3 in the desulfurization ash and the 0 valence sulfur in sulfur have a synergistic effect, effectively improving the oxidation-reduction effect with NO3 - in water, so that the system has excellent denitrification effect, and finally realizes high-efficiency denitrification reaction and waste treatment with waste.
[0026] Advantages: Compared with the prior art, the present application has the following advantages:
[0027] 1. The desulfurization ash-based denitrification filter material provided by the present application contains a main active component, and the main active component mainly contains a sulfur-containing electron donor, such as sulfur and desulfurization ash, which can effectively reduce the production cost of the desulfurization ash-based denitrification filter material by replacing part of the sulfur with industrial solid waste desulfurization ash.
[0028] 2. The +4 valence sulfur contained in CaSO3 in the desulfurization ash and the 0 valence sulfur in sulfur have a synergistic effect, effectively improving the oxidation-reduction effect with NO3 - in water, so that the system has excellent denitrification effect, and finally realizes high-efficiency denitrification reaction and waste treatment with waste.
[0029] 3. The CaSO3 and calcium hydroxide contained in the desulfurization ash are weakly alkaline, which is beneficial to neutralize the acid generated in the denitrification process, so as to ensure the stability of the effluent pH value, provide a good environment for the biofilm of denitrification microorganisms, and ensure the efficient denitrification reaction. BRIEF DESCRIPTION OF DRAWINGS
[0030] Figure 1 is a digital photo of the desulfurization ash and the denitrification filter material prepared in Example 1.
[0031] Figure 2 is a comparison of the denitrification effects of the denitrification filter materials of Example 1 and Comparative Examples 1-3. DETAILED DESCRIPTION
[0032] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of the present application.
[0033] Embodiment 1
[0034] 210 parts of solid sulfur were heated and stirred to melt to obtain an active component melt, and the temperature was kept at 140℃; 30 parts of 325 mesh calcium-based desulfurization ash and 20 parts of 325 mesh limestone were added to the active component melt, and stirred at 140℃ until uniform to obtain a denitrification filter material mother liquor; the denitrification filter material mother liquor was cooled and shaped by passing through a 4mm hole structure into a 40℃ water bath to obtain a solid waste-based denitrification filter material.
[0035] Embodiment 2
[0036] 195 parts of solid sulfur were heated and stirred to melt to obtain an active component melt, and the temperature was kept at 150℃; 45 parts of 325 mesh semi-dry desulfurization ash and 20 parts of 325 mesh calcite were added to the active component melt, and stirred at 150℃ until uniform to obtain a denitrification filter material mother liquor; the denitrification filter material mother liquor was cooled and shaped by passing through a 4mm hole structure into a 20℃ water bath to obtain a solid waste-based denitrification filter material.
[0037] Embodiment 3
[0038] 195 parts of solid sulfur were heated and stirred to melt to obtain an active component melt, and the temperature was kept at 125℃; 45 parts of 325 mesh sodium-based desulfurization ash and 15 parts of 325 mesh dolomite were added to the active component melt, and stirred at 125℃ until uniform to obtain a denitrification filter material mother liquor; the denitrification filter material mother liquor was cooled and shaped by passing through a 4mm hole structure into a 20℃ water bath to obtain a solid waste-based denitrification filter material.
[0039] Embodiment 4
[0040] 210 parts of liquid sulfur and 30 parts of dry desulfurization ash were mixed, heated and stirred to melt to obtain an active component melt, and the temperature was kept at 150℃; 30 parts of 325 mesh aragonite were added to the active component melt, and stirred at 150℃ until uniform to obtain a denitrification filter material mother liquor; the denitrification filter material mother liquor was cooled and shaped by passing through a 5mm hole structure into a 30℃ water bath to obtain a solid waste-based denitrification filter material.
[0041] Embodiment 5
[0042] Mix 210 parts of liquid sulfur and 30 parts of magnesium-based desulfurization ash and heat and stir until melted to obtain an active component melt, and keep the temperature at 160°C; add 15 parts of 325 mesh chalk to the active component melt, and stir at 160°C until uniform to obtain a denitrification filter material mother liquor; pass the denitrification filter material mother liquor through a 5 mm hole structure into a 40°C water bath to cool and form a solid waste-based denitrification filter material.
[0043] Example 6
[0044] Mix 210 parts of liquid sulfur and 40 parts of semi-dry desulfurization ash and heat and stir until melted to obtain an active component melt, and keep the temperature at 135°C; add 15 parts of 325 mesh aragonite to the active component melt, and stir at 135°C until uniform to obtain a denitrification filter material mother liquor; pass the denitrification filter material mother liquor through a 4 mm hole structure into a 40°C water bath to cool and form a solid waste-based denitrification filter material.
[0045] Example 7 Performance detection
[0046] Table 1 Physical property parameters and cost comparison of Comparative Examples 1-3 and Examples 1-6
[0047]
[0048] Comparative Example 1
[0049] Heat and stir 240 parts of solid sulfur until melted to obtain an active component melt, and keep the temperature at 140°C; add 50 parts of 325 mesh limestone to the active component melt, and stir at 140°C until uniform to obtain a denitrification filter material mother liquor; pass the denitrification filter material mother liquor through a 4 mm hole structure into a 40°C water bath to cool and form a solid waste-based denitrification filter material.
[0050] Comparative Example 2
[0051] Heat and stir 240 parts of solid sulfur until melted to obtain an active component melt, and keep the temperature at 150°C; add 20 parts of 325 mesh calcite to the active component melt, and stir at 150°C until uniform to obtain a denitrification filter material mother liquor; pass the denitrification filter material mother liquor through a 4 mm hole structure into a 20°C water bath to cool and form a solid waste-based denitrification filter material.
[0052] Comparative Example 3
[0053] Heat and stir 240 parts of solid sulfur until melted to obtain an active component melt, and keep the temperature at 125°C; add 15 parts of 325 mesh dolomite to the active component melt, and stir at 125°C until uniform to obtain a denitrification filter material mother liquor; pass the denitrification filter material mother liquor through a 4 mm hole structure into a 20°C water bath to cool and form a solid waste-based denitrification filter material.
[0054] Table 1 is a comparison of the performance parameters of conventional denitrification filter material and the filter material of Examples 1-6. It can be found that the bulk density of Examples 1-6 is 1.09 to 1.18 g / cm 3 , which is slightly higher than that of the conventional denitrification filter material; the cylinder pressure strength of Examples 1-6 is 6.9-8.4 MPa, which is 64.3%-100.0% higher than that of Comparative Example 1, and the anti-pulverization ability is obviously improved; the particle size of Examples 1-6 is 3.1-7.5 mm, which is obviously more uniform than that of the conventional autotrophic denitrification filter material of 2.5-9.5 mm; the void fraction of Examples 1-6 is 49.5-52.1%, which is obviously higher than that of the conventional autotrophic denitrification filter material of 39.2-41.10, indicating that the pore structure is more than that of the conventional autotrophic denitrification filter material.
[0055] Figure 1 It is a digital photo of the desulfurized ash-based sulfur autotrophic denitrification filter material prepared in Example 1. It can be seen that the filter material presents a regular spherical or elliptical shape, and the surface has a concave structure of different sizes, which can effectively improve the specific surface area of the filter material and is beneficial to the attachment and biofilm formation of denitrifying microorganisms, achieving the purpose of rapid start-up.
[0056] Example 8
[0057] The upflow column reactor was used to compare the denitrification effects of Examples 1 and Comparative Examples 1-3 at different residence times. The reactor material was organic glass, the main body thickness was 5 mm, the total height was 1 m, the outer diameter was 70 mm, the inner diameter was 60 mm, and the water outlet hole diameter was 2 mm. Examples 1 and Comparative Examples 1-3 were loaded into the reactor with a height of 60 cm, and the initial residence time was 20 h. Before the water was fed, 500 ml of anaerobic sludge was fed from the lower end of the reactor with 300 ml, and from the upper end with 200 ml, and then the continuous simulated wastewater was started. The parameters of the simulated wastewater used are as follows: NO3 - -N is 25 mg / L, and COD is 18.0 mg / L; after running for 10 days, the parameters of the simulated wastewater are adjusted as follows: NO3 - -N is 20 mg / L, and COD is 18.0 mg / L, and the residence time is adjusted to 15 h; in the subsequent process, only the residence time is adjusted.
[0058] Figure 2 It is a comparison of the denitrification effects of Examples 1 and Comparative Examples 1-3 at different residence times. It can be seen that under the conditions of a total nitrogen concentration of 25 mg / L in the influent and a residence time of 20 h, the filter material of Example 1 can be quickly started, and the effluent concentration decreases significantly on the 3rd day, while the start-up time of Comparative Examples 1-3 is 5-6 days; at the same time, the effluent NO3 - -N concentration of the filter material of Example 1 is stably maintained at 0.6-1.4 mg / L, which is obviously better than that of Comparative Examples 1-3. When the residence time is shortened, Example 1 can quickly adapt, and the effluent NO3- The concentration of N can be maintained at 2.0 mg / L or less, while the effluent concentrations of N03 - The concentration of N can be maintained at 2.0 mg / L or less, while the effluent concentrations of N03
[0059] The above detailed description of the embodiments of the present application is made in conjunction with the accompanying drawings and specific examples, but the present application is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present application.
Claims
1. A desulfurization ash-based denitrification and denitrification filter material, characterized in that, The ingredients include the following parts by weight: 150-255 parts by weight of elemental sulfur, 1-55 parts by weight of calcium carbonate, and 1-55 parts by weight of desulfurization ash.
2. The desulfurization ash-based denitrification and denitrification filter material according to claim 1, characterized in that, The ingredients include the following parts by weight: 195-210 parts by weight of elemental sulfur, 10-30 parts by weight of calcium carbonate, and 10-45 parts by weight of desulfurization ash.
3. The desulfurization ash-based denitrification and denitrification filter material according to claim 1, characterized in that, The ingredients include the following parts by weight: 195-210 parts by weight of elemental sulfur, 15-30 parts by weight of calcium carbonate, and 30-45 parts by weight of desulfurization ash.
4. The desulfurization ash-based denitrification and denitrification filter material according to claim 1, characterized in that, The sulfur is solid sulfur or liquid sulfur, or a mixture of the two in any proportion.
5. The desulfurization ash-based denitrification and denitrification filter material according to claim 1, characterized in that, The calcium carbonate is one or a mixture of several of the following: limestone, marble, calcite, aragonite, spherulite, dolomite, seashells, pearls, coral, eggshells, and chalk.
6. The desulfurization ash-based denitrification and denitrification filter material according to claim 1, characterized in that, The desulfurization ash is one or a mixture of several of the following: calcium-based desulfurization ash, semi-dry desulfurization ash, magnesium-based desulfurization ash, amino-based desulfurization ash, and sodium-based desulfurization ash.
7. The method for preparing the desulfurization ash-based denitrification and denitrification filter material according to any one of claims 1-6, characterized in that, Includes the following steps: S1: Heat and stir the solid sulfur material until it melts to obtain the active component melt, or mix the liquid sulfur material with desulfurization ash, heat and stir until it melts to obtain the active component melt, and maintain the melting temperature; S2: Add desulfurization ash and calcium carbonate to the active component melt in sequence, or add calcium carbonate to the active component melt and stir until uniform to obtain denitrification filter material mother liquor; S3: The mother liquor of the denitrification filter material is cooled and molded through a porous structure to obtain the desulfurization ash-based denitrification filter material.
8. The method for preparing the desulfurization ash-based denitrification filter material according to claim 7, characterized in that, In step S1, the melting temperature is 120-200℃; in step S2, the temperature under the stirring conditions is 120-200℃.
9. The method for preparing the desulfurization ash-based denitrification and denitrification filter material according to claim 7, characterized in that, In step S3, the diameter of the hole structure is 0.1-20 mm.
10. The application of the desulfurization ash-based denitrification filter media according to any one of claims 1-6 in the denitrification of nitrate-containing wastewater.