Preparation method and application of microbial agent for purifying fluorine-polluted water body

Abstract

The invention discloses a preparation method and application of a microbial agent for purifying a fluorine-polluted water body. Comprising the following steps: S1, dissolving bacillus, nitrifying bacteria, denitrifying bacteria and glucose in water, standing and aerating to obtain a bacterial suspension, fully stirring the bacterial suspension and activated charcoal, carrying out mixed adsorption, precipitating, and discarding the supernatant to obtain activated carbon mud fixed with multiple bacterial agents; s2, dissolving calcium chloride into water to prepare a calcium chloride solution, dissolving diammonium hydrogen phosphate into water to prepare a diammonium hydrogen phosphate solution, pouring the ammonium dihydrogen phosphate solution into the calcium chloride solution, and stirring to prepare a hydroxyapatite suspension; s3, polyvinyl alcohol, sodium alginate, cement and activated carbon mud are added into the hydroxyapatite turbid liquid, the mixture is put into a mold to be dried and granulated, and immobilized microbial agent particles are prepared. According to the invention, the compound microbial agent is fixed on the carrier, so that the strain is not easy to lose, the use time of microorganisms is prolonged, the adding frequency and quantity are reduced, and the use efficiency and economic benefit of the microbial agent are improved.

Description

Technical Field

[0001] The invention relates to the technical field of environmental governance, and in particular to a microbial agent for purifying fluorine-contaminated water and an application method thereof. Background Art

[0002] Microbial remediation belongs to the biodegradation method. In engineering applications, the effect of microbial remediation technology is significantly affected by the environment such as temperature, the problem of microbial loss is serious, the action time is unstable, and the activity of microorganisms is easily affected by other ion poisoning. Microbial immobilization is a bioengineering method that restricts and fixes free dominant microbial cells within a set space through physical or chemical forms to create excellent living conditions for microorganisms, so that they can maintain a high density enrichment, biological activity and proliferation level in the treatment environment. Compared with free microorganisms, immobilized microorganisms have stronger environmental tolerance, more stable physical and chemical properties, and better mass transfer performance, which can reduce the loss of bacterial agents and ensure the activity of microorganisms.

[0003] Fluoride is one of the most common anions in groundwater and surface water worldwide, but it can cause serious damage to human tissue. my country has formulated strict control standards for the safety of fluoride ion concentration in water. The A-level standard of the "Water Quality Standard for Sewage Discharge into Urban Sewers" (GB / T31962 2015) stipulates that the fluoride ion concentration in the discharged fluoride-containing wastewater cannot exceed 10 mg / L. At present, the removal process of fluoride ions generally includes membrane separation, ion exchange, adsorption and coagulation sedimentation. Among them, ion exchange and membrane separation have good effects, but require certain maintenance conditions and high cost of use; adsorption has a small processing volume and requires repeated regeneration, and the fluoride removal capacity gradually decreases; defluoridation agents achieve defluoridation effects through coagulation and sedimentation methods, which have the characteristics of low cost and simple process, but they produce a large amount of sludge and high fluoride ion content in the effluent, and there is currently no low-cost technology for the removal of fluoride ions in natural water bodies. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a microbial agent for purifying fluorine-contaminated water and an application method thereof, which has the advantages of simple preparation process, low application cost, wide applicability and high biological safety.

[0005] To achieve the above object, the preparation method of the microbial agent for purifying fluorine-contaminated water of the present invention comprises the following steps:

[0006] S1. preparing a bacterial powder mixture: dissolving Bacillus, nitrifying bacteria and denitrifying bacteria agents and glucose in water, allowing to stand and aerate to obtain a bacterial suspension, fully stirring the bacterial suspension with activated biochar for mixed adsorption, discarding the supernatant after precipitation, and obtaining activated carbon sludge fixed with multiple bacterial agents;

[0007] S2. preparing a hydroxyapatite suspension: dissolving calcium chloride in water to prepare a calcium chloride solution, dissolving diammonium hydrogen phosphate in water to prepare a diammonium hydrogen phosphate solution, and pouring the diammonium hydrogen phosphate solution into the calcium chloride solution and stirring to prepare a hydroxyapatite suspension;

[0008] S3. Preparation of immobilized particles: adding polyvinyl alcohol, sodium alginate, cement and activated carbon mud into hydroxyapatite suspension, placing the mixture into a mold, drying and granulating to obtain immobilized bacterial agent particles.

[0009] Furthermore, the preparation method of the activated carbon is: salvaging aquatic plants from a river, drying them, breaking them into small pieces, and performing pyrolysis to obtain activated biochar, and the biochar is ground by a grinding device and then sieved for later use.

[0010] Furthermore, the pyrolysis temperature is 700°C to 850°C, and the pyrolysis time is 1 to 2 hours.

[0011] Furthermore, in step S1, the mass ratio of the bacillus agent, the nitrifying bacteria agent, the denitrifying bacteria agent, the glucose and the water is 2-4:1-2:1-2:10-20:500-1000.

[0012] Furthermore, in step S2, the mass concentration of the calcium chloride solution is about 10%, the mass concentration of the diammonium phosphate solution is about 12%, and the volume ratio is 1:0.6;

[0013] Furthermore, in step S3, the mass ratio of polyvinyl alcohol, sodium alginate, cement and activated carbon mud is 1:2-4:8-15:15-30.

[0014] Furthermore, in step S3, the mass ratio of the hydroxyapatite suspension to the coarse powder is 1 to 2:1.

[0015] Furthermore, in step S3, the particle diameter is 3-10 mm, the drying temperature is 35° C. to 40° C., and the drying time is 2 to 6 hours.

[0016] Furthermore, in step S1, the mass ratio of the bacterial suspension to the activated carbon mud is 1 to 3:1.

[0017] To achieve the above purpose, the present invention uses the microbial agent for purifying fluorine-contaminated water in the contaminated water. The immobilized microbial agent particles can be directly put into the target water body, or combined with other in-situ ecological management measures such as ecological floating islands and submerged plant blankets.

[0018] The present invention prepares activated biochar using salvaged aquatic plants, embeds microorganisms, uses cement to improve the mechanical strength of the immobilized carrier, and mixes hydroxyapatite as a defluoridating agent, which can effectively reduce the fluoride ion concentration in the water body while removing conventional pollutants.

[0019] Specifically, compared with the prior art, the present invention has the following beneficial effects:

[0020] 1) This method fixes the composite microbial agent on the carrier, and the strains are not easy to lose, which improves the resistance, survival ability and treatment efficiency of the agent in the environment, prolongs the use time of the microorganisms, reduces the number and amount of additions, and improves the use efficiency and economic benefits of the agent. The microorganisms peeled off from the carrier enter the water body, which can continuously improve the microbial community structure in the water body.

[0021] 2) This method uses biochar prepared from salvaged aquatic plants as a carrier, which has a stronger ability to fix microbial cells and can effectively adsorb pollutants in the water, thus achieving resource recycling.

[0022] 3) The immobilized bacterial agent prepared by this method is mixed with hydroxyapatite as a slow-release defluoridation agent, which can effectively reduce the fluoride ion concentration in water bodies for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the process flow of the present invention.

[0024] Figure 2 The activated carbon mud of the present invention;

[0025] Figure 3 This is the immobilized bacterial agent particle sample of the present invention. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0027] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The microbial in-situ remediation method for contaminated water bodies of the present invention specifically includes the following embodiments:

[0031] Example 1

[0032] A method for in-situ microbial remediation of polluted water bodies, comprising the following steps:

[0033] S1. Preparation of activated biochar: salvage aquatic plants from the river, dry them in the sun for 48 hours, break them into small pieces of about 1-3 cm, perform pyrolysis to obtain activated biochar, grind them through a grinding device, and pass through a 300-mesh sieve for later use;

[0034] S2. Prepare a bacterial powder mixture: dissolve 4 g of Bacillus, 2 g of nitrifying bacteria, 2 g of denitrifying bacteria powder and 15 g of glucose in 200 ml of deionized water, stir thoroughly for 15 min to obtain a bacterial suspension, take 200 ml of the bacterial suspension and 50 g of activated carbon, stir thoroughly for 2 h, let stand and settle for 30 min, discard the supernatant to obtain activated carbon sludge adsorbed with the bacterial agent;

[0035] S3, preparing a hydroxyapatite suspension: dissolving 6 g of anhydrous calcium chloride in 60 ml of water to prepare a calcium chloride solution, dissolving 4.5 g of diammonium hydrogen phosphate in 40 ml of water to prepare a diammonium hydrogen phosphate solution, pouring the diammonium hydrogen phosphate solution into the calcium chloride solution and stirring to prepare a hydroxyapatite suspension;

[0036] S4, preparing immobilized particles: 2g polyvinyl alcohol, 6g sodium alginate, 30g cement and activated carbon mud were uniformly mixed to obtain immobilized bacterial agent coarse powder, 100ml hydroxyapatite suspension was added, and a solid mixture was obtained after sufficient mixing. The mixture was put into a mold, granulated to obtain immobilized bacterial agent particles, and then dried at 40°C for 3h;

[0037] S5. Add the immobilized bacterial agent particles into the artificially prepared sewage in the laboratory, with the addition amount being 20 g / L and the loaded microorganism amount being about 1600 mg / L.

[0038] The artificial sewage composition was 80 mg / L COD, 15 mg / L ammonia nitrogen, and 5 mg / L fluoride ions to simulate eutrophic water bodies contaminated by fluoride ions. It was placed in a plexiglass box and stirred at a low speed to simulate natural water bodies. After adding the immobilized bacterial agent particles, water was taken every 3 days to test its COD, ammonia nitrogen, and fluoride ion concentrations. On the 15th day of the experiment, the COD in the artificial sewage dropped to 24.6 mg / L, the ammonia nitrogen dropped to 0.68 mg / L, and the fluoride ion dropped to about 1.3 mg / L.

[0039] Example 2

[0040] A method for in-situ microbial remediation of polluted water bodies, comprising the following steps:

[0041] S1. Preparation of activated biochar: salvage aquatic plants from the river, dry them in the sun for 48 hours, break them into small pieces of about 1-3 cm, perform pyrolysis to obtain activated biochar, grind them through a grinding device, and pass through a 300-mesh sieve for later use;

[0042] S2. Prepare a bacterial powder mixture: dissolve 2 kg of Bacillus, 1 kg of nitrifying bacteria, 1 kg of denitrifying bacteria powder and 7.5 kg of glucose in 100 L of deionized water, stir thoroughly for 30 min to obtain a bacterial suspension, stir the bacterial suspension with 25 kg of activated carbon prepared in step S1 for 2 h, let it stand and settle for 30 min, and discard the supernatant to obtain activated carbon sludge adsorbed with the bacterial agent;

[0043] S3, preparing a hydroxyapatite suspension: dissolving 3 kg of anhydrous calcium chloride into 30 L of water to prepare a calcium chloride solution, dissolving 2.25 kg of diammonium hydrogen phosphate into 20 L of water to prepare a diammonium hydrogen phosphate solution, and pouring the diammonium hydrogen phosphate solution into the calcium chloride solution and stirring to prepare a hydroxyapatite suspension;

[0044] S4, preparing immobilized particles: 1 kg of polyvinyl alcohol, 3 kg of sodium alginate, 15 kg of cement and activated carbon mud are uniformly mixed to obtain immobilized bacterial agent coarse powder, and the powder is added to the hydroxyapatite suspension prepared in S3, and the solid mixture is obtained after sufficient mixing. The mixture is put into a mold, granulated to obtain immobilized bacterial agent particles, and then dried at 40° C. for 3 h;

[0045] S5. Add the immobilized bacterial agent particles into a water body seriously polluted by overflow in Maanshan City, with a dosage of 20 kg / m2 and a loaded microbial mass of about 800 mg / L.

[0046] The present invention is described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present invention. Many other changes and modifications that do not depart from the concept and scope of the present invention should be regarded as the protection scope of the present invention.

[0047] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0048] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing a microbial agent for purifying fluorine-contaminated water, characterized in that: The method specifically comprises the following steps: S1. preparing a bacterial powder mixture: dissolving Bacillus, nitrifying bacteria and denitrifying bacteria agents and glucose in water, allowing to stand and aerate to obtain a bacterial suspension, fully stirring the bacterial suspension with activated biochar for mixed adsorption, discarding the supernatant after precipitation, and obtaining activated carbon sludge fixed with multiple bacterial agents; S2. preparing a hydroxyapatite suspension: dissolving calcium chloride in water to prepare a calcium chloride solution, dissolving diammonium hydrogen phosphate in water to prepare a diammonium hydrogen phosphate solution, and pouring the diammonium hydrogen phosphate solution into the calcium chloride solution and stirring to prepare a hydroxyapatite suspension; S3. Preparation of immobilized particles: adding polyvinyl alcohol, sodium alginate, cement and activated carbon mud into hydroxyapatite suspension, placing the mixture into a mold, drying and granulating to obtain immobilized bacterial agent particles.

2. The method for preparing a microbial agent for purifying fluorine-contaminated water according to claim 1, characterized in that: The preparation method of the activated carbon is as follows: salvage aquatic plants from a river, dry them in the sun, break them into small pieces, and perform pyrolysis to obtain activated biochar; the biochar is ground by a grinding device and then sieved for later use.

3. The method for preparing a microbial agent for purifying fluorine-contaminated water according to claim 2, characterized in that: The pyrolysis temperature is 700° C. to 850° C., and the pyrolysis time is 1 to 2 hours.

4. The method for preparing a microbial agent for purifying fluorine-contaminated water according to claim 1, characterized in that: In the step S1, the mass ratio of the bacillus agent, the nitrifying bacteria agent, the denitrifying bacteria agent, the glucose and the water is 2-4:1-2:1-2:10-20:500-1000.

5. The method for preparing a microbial agent for purifying fluorine-contaminated water according to claim 1, characterized in that: In step S2, the mass concentration of the calcium chloride solution is about 10%, the mass concentration of the diammonium phosphate solution is about 12%, and the volume ratio is 1:0.

6.

6. The method for preparing a microbial agent for purifying fluorine-contaminated water according to claim 1, characterized in that: In step S3, the mass ratio of polyvinyl alcohol, sodium alginate, cement and activated carbon mud is 1:2-4:8-15:15-30.

7. The method for preparing a microbial agent for purifying fluorine-contaminated water according to claim 1, characterized in that: In the step S3, the mass ratio of the hydroxyapatite suspension to the coarse powder is 1-2:

1.

8. The method for preparing a microbial agent for purifying fluorine-contaminated water according to claim 1, characterized in that: In step S3, the particle diameter is 3-10 mm, the drying temperature is 35° C. to 40° C., and the drying time is 2 to 6 hours.

9. The method for preparing a microbial agent for purifying fluorine-contaminated water according to claim 1, characterized in that: In step S1, the mass ratio of the bacterial suspension to the activated carbon mud is 1 to 3:

1.

10. Application of a microbial agent for purifying fluorine-contaminated water in contaminated water.

Images