Iron sulfide oxide composite denitrification filler as well as preparation method and application thereof

Abstract

The invention discloses a sulfur iron oxide composite denitrification filler, a preparation method and application, and relates to the technical field of sewage treatment, the sulfur iron oxide composite denitrification filler comprises sulfur powder, siderite, magnesite, magnesium oxide, metal manganese, metal aluminum, nano iron, boric sludge, magnetite and a binder; wherein the sum of the addition amounts of the metal manganese, the metal aluminum and the nano iron accounts for 8-16% of the mass of the sulfur-iron oxide composite denitrification filler. The technical problems that in the prior art, strength and abrasion resistance are insufficient, and denitrification efficiency is low are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sewage treatment, in particular to a ferrous sulfide composite denitrification filler, a preparation method and application. BACKGROUND

[0002] Traditional heterotrophic denitrification has defects such as large carbon source consumption and high sludge production, while sulfur autotrophic denitrification as an inorganic denitrification technology can achieve deep denitrification without additional carbon source, has broad application prospects in the field of low-carbon efficient denitrification, and becomes one of the core directions of the iteration and upgrading of biological denitrification technology of sewage. The existing ferrous sulfide composite denitrification filler is mainly prepared from siderite, sulfur powder and magnesite. The filler takes reduced state sulfur S 0 and iron as the main electron donor, takes NO3 - -N as the electron acceptor, and obtains energy by oxidizing the redox state sulfur to reduce NO3 - -N to nitrogen. The sulfur autotrophic denitrification process consumes alkalinity, and the composite mineral provides alkalinity, so that the two are combined to maintain the progress of the denitrification system by controlling a certain proportion.

[0003] However, the ferrous sulfide composite denitrification filler prepared by the existing granulation technology has problems of low enrichment abundance of denitrification microorganisms and low denitrification efficiency. The denitrification efficiency of the filler is generally 0.4-0.6 kgN / m 3 / d, the denitrification efficiency decreases with time, cannot be maintained stable, and the strength and wear resistance of the filler are insufficient. In actual engineering projects, the filler is worn too much, causing invalid loss of the filler, and the lost sulfur autotrophic filler accumulates in the pipeline and is reduced to hydrogen sulfide by sulfate-reducing bacteria under anaerobic environmental conditions, producing odor and corroding the pipeline. SUMMARY

[0004] The purpose of the present application is to provide a ferrous sulfide composite denitrification filler, a preparation method and application to solve at least one of the above technical problems.

[0005] In a first aspect, the present application provides a ferrous sulfide composite denitrification filler, comprising: sulfur powder, siderite, magnesite, magnesium oxide, metallic manganese, metallic aluminum, nano-iron, boron mud, magnetite and a binder; wherein the sum of the addition amounts of the metallic manganese, the metallic aluminum and the nano-iron accounts for 8% to 16% of the mass of the ferrous sulfide composite denitrification filler.

[0006] Further, the boron mud comprises a mixture of silicon dioxide, diboron trioxide and aluminum oxide.

[0007] Further, the particle size of the sulfur powder is greater than 130 mesh.

[0008] Further, the particle size of the siderite, the magnesite and the magnetite is 50-120 mesh.

[0009] Further, the binder comprises one or more of the following in combination: diatomite, gypsum, Portland cement, quartz sand, kaolin.

[0010] Further, the mass ratio of the sulfur powder, the siderite, the magnesite, the magnesium oxide, the metal manganese, the metal aluminum, the nano-iron, the boron mud, the magnetite and the binder in the sulfur-iron oxide composite denitrification filler is 28-60%, 5-30%, 5-25%, 3-10%, 3-15% and 5-15% respectively.

[0011] In the second aspect, the present application further provides a preparation method of a sulfur-iron oxide composite denitrification filler, which comprises the following steps: uniformly mixing sulfur powder, siderite, magnesite, magnesium oxide, metal manganese, metal aluminum, nano-iron, boron mud, magnetite and a binder according to a preset mass ratio to obtain an initial denitrification filler; adding water to the initial denitrification filler and continuing to mix, and then performing raw material molding by using an extrusion granulation or a disc granulation to obtain a molded denitrification filler; performing drying treatment on the molded denitrification filler to obtain a dried denitrification filler; and performing sintering treatment on the dried denitrification filler to obtain the sulfur-iron oxide composite denitrification filler.

[0012] Further, the sintering treatment on the dried denitrification filler to obtain the sulfur-iron oxide composite denitrification filler comprises the following steps: placing the dried denitrification filler in a calcining furnace to perform primary sintering treatment to obtain a primary calcined denitrification filler; placing the primary calcined denitrification filler in a vacuum sintering furnace to perform secondary sintering treatment to obtain the sulfur-iron oxide composite denitrification filler; and wherein inert gas is introduced during the secondary sintering treatment.

[0013] In the third aspect, the present application further provides an application of a sulfur-iron oxide composite denitrification filler in sewage treatment, wherein the sulfur-iron oxide composite denitrification filler is used in a sulfur autotrophic denitrification process.

[0014] The present application provides a sulfur-iron oxide composite denitrification filler, a preparation method and an application, wherein metal manganese and nano-iron are added in the denitrification filler to strengthen the removal of nitrogen elements by relevant functional microorganisms using iron elements; the components in the denitrification filler, i.e. magnetite and metal manganese, promote the enrichment of functional microorganisms such as denitrifying sulfur-oxidizing bacteria and desulfovibrio, and indirectly strengthen the removal of nitrogen elements by microorganisms using sulfur elements; in the preparation method of the denitrification filler, a secondary sintering processing technology is used to further improve the strength of the denitrification filler and reduce the breakage rate and the abrasion rate of the filler during use. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0016] Figure 1 A flow chart of a preparation method of a ferrous sulfide oxide composite denitration filler provided by an embodiment of the present application is shown in the figure. Figure 2 A denitration efficiency diagram of a ferrous sulfide oxide composite denitration filler obtained by a preparation method provided by an embodiment of the present application is shown in the figure. Figure 3 A schematic diagram of a water treatment experimental device provided by an embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0018] The present application provides a ferrous sulfide oxide composite denitration filler, comprising: sulfur powder, siderite, magnesite, magnesium oxide, metallic manganese, metallic aluminum, nano-iron, boron mud, magnetite and a binder; wherein, The sum of the addition amounts of the metallic manganese and the metallic aluminum is 8% to 16% of the mass of the ferrous sulfide oxide composite denitration filler.

[0019] Specifically, in the embodiments of the present application, the boron mud comprises a mixture of silicon dioxide, diboron trioxide and aluminum oxide.

[0020] Preferably, the particle size of the sulfur powder is greater than 130 mesh.

[0021] Preferably, the particle size of the siderite, the magnesite and the magnetite is 50 mesh to 120 mesh.

[0022] Preferably, the binder comprises any one or a combination of the following: diatomite, gypsum, Portland cement, quartz sand and kaolin. For example, the binder can be diatomite or kaolin, or a mixture of gypsum, Portland cement and quartz sand.

[0023] Preferably, the mass proportions of sulfur powder, siderite, magnesite, magnetite, boron mud and binder in the sulfur-iron oxide composite denitrification filler are 28% to 60%, 5% to 30%, 5% to 25%, 3% to 10%, 3% to 15% and 5% to 15% respectively.

[0024] Specifically, the main component of the magnetite is Fe3O4, which is composed of Fe 2+ and Fe 3+ , and can be regarded as a conforming oxide of FeO·Fe2O3.

[0025] The sulfur-iron oxide composite denitrification filler provided by the embodiment of the present application provides sufficient reducibility for the denitrification filler by adding metal manganese, Fe 2+ and nano-iron in the preparation raw material; the metal manganese is added to cause oxidation-reduction reaction with Fe 2+ and Fe 3+ , so as to reduce the oxidized Fe element, so that the denitrification filler can have more durable reducibility. The specific chemical reaction formula is as follows: 3+ Fe 2+ Mn+2Fe 3+ →Mn 2+ +2Fe 2+ Fe 2+ +2e⁻→Fe Mn+Fe 2+ →Mn 2+ +Fe Meanwhile, the iron-manganese reaction forms a primary battery system, accelerates the electron transfer efficiency, helps to accelerate the reaction rate of functional microorganisms and improves the denitrification effect.

[0026] Figure 1 is a flow chart of a preparation method of a sulfur-iron oxide composite denitrification filler according to the embodiment of the present application. As shown in Figure 1 , the method specifically includes the following steps: In step S102, sulfur powder, siderite, magnesite, magnesium oxide, metal manganese, metal aluminum, nano-iron, boron mud, magnetite and binder are uniformly mixed according to preset mass proportions to obtain an initial denitrification filler.

[0027] The preset mass proportions include: The sum of the addition amounts of the metal manganese, the metal aluminum and the nano-iron is 8% to 16% of the mass proportion of the sulfur-iron oxide composite denitrification filler. The mass ratio of sulfur powder, siderite, magnesite, magnetite, boron mud and binder in the sulfur-iron oxide composite denitrification filler is respectively: 28%-60%, 5%-30%, 5%-25%, 3%-10%, 3%-15%, 5%-15%; Step S104, water is added to the initial denitrification filler for continuous mixing, and the raw materials are formed by extrusion granulation or disc granulation to obtain the formed denitrification filler.

[0028] Step S106, the formed denitrification filler is dried to obtain the dried denitrification filler.

[0029] Specifically, the formed denitrification filler is placed in an oven for drying.

[0030] Preferably, the drying temperature includes but is not limited to 160℃, 180℃; the drying time includes but is not limited to 45mim, 120min.

[0031] Step S108, the dried denitrification filler is sintered to obtain the sulfur-iron oxide composite denitrification filler.

[0032] Specifically, step S108 further includes the following steps: Step S1081, the dried denitrification filler is placed in a calcining furnace for primary sintering treatment to obtain the primary calcined denitrification filler.

[0033] Specifically, the dried denitrification filler is placed in a calcining furnace and calcined at 350℃ for 2.5 hours to obtain the primary calcined denitrification filler.

[0034] Step S1082, the primary calcined denitrification filler is placed in a vacuum sintering furnace for secondary sintering treatment to obtain the sulfur-iron oxide composite denitrification filler; wherein inert gas is introduced during the secondary sintering treatment.

[0035] Specifically, the primary calcined denitrification filler is cooled to room temperature and then placed in a vacuum sintering furnace, heated to 420℃ at a rate of 5℃ / min for 2.5 hours, then heated to 500℃ for 6.5 hours, and finally heated to 600℃ for 9 hours, and inert gas is introduced during the sintering process.

[0036] Preferably, the temperature control accuracy of the vacuum sintering furnace is ±5℃, and the inert gas is argon.

[0037] The preparation method provided by the embodiment of the present application adopts a vacuum sintering furnace for secondary sintering, is equipped with a high-precision temperature control system (temperature control precision is ± 5℃), and ensures the uniformity of the temperature in the furnace. The vacuum is realized by means of vacuumizing or introducing inert gas (such as argon) protection. First, the temperature is raised to 420℃ at a rate of 5℃ / min, and the adsorbed water is removed by keeping the temperature for 2.5 hours, and then the temperature is raised to the target temperature, so as to reduce the risk of powder explosion. The initial reaction is promoted by keeping the temperature at 500℃ for 6.5 hours, and then the temperature is raised to 600℃ to accelerate diffusion. The metal manganese and aluminum atoms are diffused to form Al6Mn phase under the condition of keeping the temperature at 600℃ for 9 hours, so that the denitrification filler has excellent strength, hardness and wear resistance.

[0038] Figure 2 Figure is a denitrification efficiency diagram of the ferrous sulfide oxide composite denitrification filler obtained by the preparation method provided by the embodiment of the present application, Figure 3 Figure is a schematic diagram of a water treatment experimental device provided by the embodiment of the present application. As shown in Figure Figure 2 The ferrous sulfide oxide composite denitrification filler obtained by the preparation method provided by the embodiment of the present application has high denitrification efficiency, and the removal rate of NO3 Figure 3 -N can be stabilized at more than 97% after running for more than 10 days in the experimental device shown in Figure - 20℃ water temperature, and the denitrification load range of the filler is stabilized at 1.43-1.82kgN / m3 / d; meanwhile, the breakage rate and the abrasion rate during use are low, and the average value of the breakage rate + the abrasion rate is 0.03%.

[0039] The embodiment of the present application also provides an application of the ferrous sulfide oxide composite denitrification filler in sewage treatment, wherein the ferrous sulfide oxide composite denitrification filler is used in a sulfur autotrophic denitrification process.

[0040] It is apparent for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, but can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and range of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0041] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the specification is described in this way only for the sake of clarity, and those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be properly combined to form other embodiments that those skilled in the art can understand.

Claims

1. A ferrous-sulphur oxide composite denitration filler, characterized in that, Comprising: sulfur powder, siderite, magnesite, magnesium oxide, metallic manganese, metallic aluminum, nano-iron, boron mud, magnetite and a binder; wherein, The sum of the addition amount of the metallic manganese, the metallic aluminum and the nano-iron accounts for 8% to 16% of the mass of the sulfur-iron oxide composite denitrification filler.

2. The ferrous-sulfur oxide composite denitrification media of claim 1, wherein: The boron mud comprises a mixture of silicon dioxide, diboron trioxide and aluminum oxide.

3. The ferrous-sulfur oxide composite denitrification media of claim 1, wherein: The particle size of the sulfur powder is greater than 130 mesh.

4. The ferrous-sulfur oxide composite denitrification media of claim 1, wherein: The particle size of the siderite, the magnesite and the magnetite is 50 mesh to 120 mesh.

5. The ferrous-sulfur oxide composite denitrification media of claim 1, wherein: The binder comprises a combination of one or more of the following: diatomite, gypsum, Portland cement, quartz sand, kaolin.

6. The ferrous-sulfur oxide composite denitrification media of claim 1, wherein: The mass proportions of the sulfur powder, the siderite, the magnesite, the magnetite, the boron mud and the binder in the sulfur-iron oxide composite denitrification filler are respectively: 28% to 60%, 5% to 30%, 5% to 25%, 3% to 10%, 3% to 15%, 5% to 15%.

7. A process for the production of the sulphur-iron oxide composite denitration filler according to any one of claims 1 to 6, characterized in that, Comprising: Sulfur powder, siderite, magnesite, magnesium oxide, metallic manganese, metallic aluminum, nano-iron, boron mud, magnetite and a binder are uniformly mixed according to predetermined mass proportions to obtain an initial denitrification filler; Water is added to the initial denitrification filler for further mixing, and the raw materials are formed by extrusion granulation or disc granulation to obtain a formed denitrification filler; The formed denitrification filler is subjected to drying treatment to obtain a dried denitrification filler; The dried denitrification filler is subjected to sintering treatment to obtain the sulfur-iron oxide composite denitrification filler.

8. The method of claim 7, wherein: The dried denitrification filler is subjected to sintering treatment to obtain the sulfur-iron oxide composite denitrification filler, comprising: The dried denitrification filler is placed in a calcination furnace for primary sintering treatment to obtain a primary calcined denitrification filler; The primary calcined denitrification filler is placed in a vacuum sintering furnace for secondary sintering treatment to obtain the sulfur-iron oxide composite denitrification filler; During the secondary sintering treatment, inert gas is introduced.

9. Use of the sulphur-iron oxide composite denitrification filler according to any one of claims 1 to 6 in sewage treatment, characterized in that, The sulfur-iron oxide composite denitrification filler is used in a sulfur autotrophic denitrification process.

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