Method for recovering filamentous fungus type expanded halophilic granular sludge by using magnetic powder

Abstract

The invention discloses a method for recovering filamentous fungus type expanded halophilic granular sludge by using magnetic powder, and belongs to the technical field of sewage treatment. According to the basic principle of the method, magnetic powder is added, and differential toxicity of the magnetic powder to bacteria and fungi is utilized, so that the purpose of inhibiting proliferation of the filamentous fungi is achieved, the population number of the fungi is reduced, and recovery of the filamentous fungus type expanded halophilic granular sludge is achieved. In this way, the sludge with fungi growing in an outbreak mode can be recovered into a flocculent structure in a short time, HAGS with the magnetic powder as the core is formed, and the good performance of sewage treatment is recovered again. Adding of the magnetic powder is a physical regulation and control mode without secondary pollution, operation is convenient, and the magnetic powder can be attracted by a magnet to be recycled and reused. The method is remarkable in effect and low in cost.

Description

Technical Field

[0001] The invention belongs to the field of sewage treatment, and in particular relates to a method for recovering filamentous fungus-type expanded halophilic granular sludge by using magnetic powder. Background Art

[0002] Halophilic aerobic granular sludge (HAGS) has been proven to be an effective technology for treating high-salinity organic wastewater due to its small footprint, excellent pollutant removal ability, and strong resistance to shock loads. The stability of the particle structure and function is crucial to the long-term stable operation of HAGS. However, recent studies have found that sludge bulking problems caused by excessive growth of filamentous fungi occur in HAGS. This is because the filamentous fungi in the form of skeletons in HAGS extend from the core to the surface of the particles, gain competitive advantages, and multiply in large numbers. The excessive growth of filamentous fungi leads to fluffy granular sludge structure, deterioration of sedimentation capacity, loss of microorganisms, and decreased treatment effect, affecting the stable operation of HAGS. Therefore, it is urgent to propose a method to restore filamentous fungus-type bulking HAGS.

[0003] At present, the common method of inhibiting the growth of filamentous microorganisms is to indirectly achieve effective sludge separation through process adjustment. Studies have shown that adjusting process parameters such as sludge retention time, nutrient ratio, influent load and dissolved oxygen concentration can effectively inhibit sludge swelling. However, these methods are time-consuming and costly. The addition of physical and chemical agents has been proven to be an effective strategy to inhibit filamentous microorganisms. Chemical reagents are fast-acting and low-cost, but they increase the risk of re-pollution. Physical additives can avoid the above risks, but their research often focuses on the formation of granular sludge, while ignoring their potential role in inhibiting the excessive growth of filamentous microorganisms.

[0004] In response to the above problems, this patent proposes a method for restoring fungal bulking sludge using magnetic powder. The difference in magnetic biological effect and toxic effect of magnetic powder on fungi and bacteria is used to inhibit the proliferation of filamentous fungi and reduce the population of fungi. Summary of the invention

[0005] The purpose of the present invention is to quickly inhibit the excessive proliferation of filamentous fungi, solve the sludge bulking problem caused by the excessive growth of filamentous fungi, and restore the disintegrated HAGS at the same time.

[0006] The present invention provides a method for recovering filamentous fungal type halophilic granular sludge by using magnetic powder, which is characterized by: adding magnetic powder to the fungal type sludge, using the different magnetic biological effects and toxic effects of the magnetic powder on fungi and bacteria, inhibiting the proliferation of filamentous fungi, reducing the fungal population, and thus recovering the fungal type sludge. At the same time, the magnetic powder is used as a crystal nucleus to adsorb the attachment and growth of microorganisms and promote the formation of HAGS. It includes the following steps:

[0007] Step 1: Prepare a concentrated mother solution with a magnetic powder concentration of 1.0 to 10.0 g / L.

[0008] Step 2: When the reactor sludge is uniformly mixed, the mother liquor is introduced into the sludge that has undergone filamentous fungus type swelling, so that the magnetic powder concentration in the reactor reaches 0.1-1.0 g / L.

[0009] Step 3: Add magnetic powder to the reactor every 10 days until there are no filamentous bacteria visible to the naked eye. Stop adding magnetic powder. The amount of magnetic powder added is calculated according to the following formula: Where M is the amount of magnetic powder added, g; SRT is the sludge retention time, d; C is the initial concentration of magnetic powder in the reactor, g / L; V is the reactor volume, L. The volume of magnetic powder mother liquor converted is: Where W is the added volume of magnetic powder mother solution, L; M is the added amount of magnetic powder, g; A is the concentration of magnetic powder mother solution.

[0010] Step 4: The remaining magnetic powder in the reactor is recovered by applying magnets on both sides of the reactor.

[0011] The technical principle of the present invention is that the magnetic powder produces differential toxicity attacks on fungi and bacteria, resulting in differences in quantity. See the schematic diagram for the principle. Figure 2 .

[0012] The interfacial interaction between magnetic powder and filamentous fungi leads to membrane penetration, which is an important cause of the death of filamentous fungi. Through previous studies, we found that magnetic powder with a concentration of 0.1-1.0 g / L and a particle size of 200 nm, 10 μm, and 50 μm can significantly reduce the number of fungi, but has little effect on the number of bacteria. When magnetic powder of the same concentration and particle size is added, fungal proliferation is significantly inhibited, the number of fungi is significantly reduced, and the proportion of filamentous fungi is greatly reduced. The magnetic biological effect produced by magnetic powder induces changes in the thermodynamic properties of the sludge surface, resulting in enhanced sludge aggregation ability. The granular magnetic powder is wrapped in sludge clusters, and the filamentous fungi that dominate the clusters by virtue of their volume advantage use their strong hyphae structure to capture the magnetic powder. This increases the contact sites between filamentous fungi and magnetic powder, providing favorable conditions for magnetic powder to penetrate the cell membrane through physical osmosis. The rupture of the cell membrane is accompanied by the death of the cell and flows out with the drainage. By applying this principle to develop technical methods, the recovery of fungal bulking sludge and the formation of HAGS can be achieved, which provides valuable guidance for the sustained and stable operation of HAGS technology in practice.

[0013] Compared with the prior art, the advantages of the present invention are:

[0014] (1) By adding magnetic powder to differentially attack bacteria and fungi with toxicity, the fungal population is reduced, thus achieving the recovery of fungal bulking sludge.

[0015] (2) The magnetic powder added in the present invention is an inert material, has no risk of leaching, and can be recycled after being attracted by a magnet. Therefore, the exogenous addition of magnetic powder is a green, non-toxic, and environmentally friendly means of controlling sludge bulking.

[0016] (3) The method of the present invention is easy to operate, simple, low-cost, stable and reliable.

[0017] (4) Magnetic powder has strong adsorption capacity. After the fungi are inhibited, the residual magnetic powder in the reactor can serve as a core carrier to provide attachment points for microorganisms in the early stage of granulation, and provide a stable core for the granular sludge in the mature stage, thereby enhancing the stability of the granular sludge in long-term stable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the reactor

[0019] Reactor (1), temperature control device (2), water inlet tank (3), water inlet pump (4), air pump (5), aeration plate (6), water outlet (7);

[0020] Figure 2 This is a schematic diagram of the present invention. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below in conjunction with the examples. The following examples are implemented on the premise of the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the present invention is not limited to the following examples.

[0022] Example 1: Magnetic powder recovery of fungal bulking sludge with a dosing concentration of 0.1 g / L and a particle size of 200 nm

[0023] Step 1: Prepare a concentrated mother solution with a magnetic powder concentration of 1.0 g / L and a particle size of 200 nm.

[0024] Step 2: When the reactor sludge is uniformly mixed, the mother liquor is introduced into the sludge that has undergone filamentous fungus type swelling, so that the magnetic powder concentration in the reactor reaches 0.1g / L.

[0025] Step 3: Add 0.2 g of 200 nm magnetic powder to the reactor every 10 days. When no filamentous bacteria are visible to the naked eye in the reactor on the 40th day, stop adding.

[0026] Step 4: The remaining magnetic powder in the reactor is recovered by applying magnets on both sides of the reactor.

[0027] Example 2: Magnetic powder with a dosing concentration of 0.1 g / L and a particle size of 10 μm was used to restore fungal bulking sludge

[0028] Step 1: Prepare a concentrated mother solution with a magnetic powder concentration of 1.0 g / L and a particle size of 10 μm.

[0029] Step 2: When the reactor sludge is uniformly mixed, the mother liquor is introduced into the sludge that has undergone filamentous fungus type swelling, so that the magnetic powder concentration in the reactor reaches 0.1g / L.

[0030] Step 3: Add 0.2 g of 10 μm magnetic powder to the reactor every 10 days. Stop adding magnetic powder when no filamentous bacteria are visible in the reactor on the 40th day.

[0031] Step 4: The remaining magnetic powder in the reactor is recovered by applying magnets on both sides of the reactor.

[0032] Example 3: Magnetic powder with a dosing concentration of 0.1 g / L and a particle size of 50 μm was used to restore fungal bulking sludge

[0033] Step 1: Prepare a concentrated mother solution with a magnetic powder concentration of 1.0 g / L and a particle size of 50 μm.

[0034] Step 2: When the reactor sludge is uniformly mixed, the mother liquor is introduced into the sludge that has undergone filamentous fungus type swelling, so that the magnetic powder concentration in the reactor reaches 0.1g / L.

[0035] Step 3: Add 0.2 g of 50 μm magnetic powder to the reactor every 10 days. Stop adding magnetic powder when no filamentous bacteria are visible in the reactor on the 40th day.

[0036] Step 4: The remaining magnetic powder in the reactor is recovered by applying magnets on both sides of the reactor.

[0037] Example 4: Recovery of fungal bulking sludge by magnetic powder with a dosing concentration of 0.5 g / L and a particle size of 200 nm

[0038] Step 1: Prepare a concentrated mother solution with a magnetic powder concentration of 5.0 g / L and a particle size of 200 nm.

[0039] Step 2: When the reactor sludge is uniformly mixed, the mother liquor is introduced into the sludge that has undergone filamentous fungus type swelling, so that the magnetic powder concentration in the reactor reaches 0.5g / L.

[0040] Step 3: Add 1.0 g of 200 nm magnetic powder to the reactor every 10 days. Stop adding magnetic powder on the 20th day when no filamentous bacteria are visible in the reactor.

[0041] Step 4: The remaining magnetic powder in the reactor is recovered by applying magnets on both sides of the reactor.

[0042] Example 5: Recovery of fungal bulking sludge by magnetic powder with a dosing concentration of 0.5 g / L and a particle size of 10 μm

[0043] Step 1: Prepare a concentrated mother solution with a magnetic powder concentration of 5.0 g / L and a particle size of 10 μm.

[0044] Step 2: When the reactor sludge is uniformly mixed, the mother liquor is introduced into the sludge that has undergone filamentous fungus type swelling, so that the magnetic powder concentration in the reactor reaches 0.5g / L.

[0045] Step 3: Add 1.0 g of 10 μm magnetic powder to the reactor every 10 days. Stop adding magnetic powder on the 30th day when no filamentous bacteria are visible in the reactor.

[0046] Step 4: The remaining magnetic powder in the reactor is recovered by applying magnets on both sides of the reactor.

[0047] Example 6: Magnetic powder with a concentration of 0.5 g / L and a particle size of 50 μm was used to restore fungal bulking sludge

[0048] Step 1: Prepare a concentrated mother solution with a magnetic powder concentration of 5.0 g / L and a particle size of 50 μm.

[0049] Step 2: When the reactor sludge is uniformly mixed, the mother liquor is introduced into the sludge that has undergone filamentous fungus type swelling, so that the magnetic powder concentration in the reactor reaches 0.5g / L.

[0050] Step 3: Add 1.0 g of 50 μm magnetic powder to the reactor every 10 days. Stop adding magnetic powder when no filamentous bacteria are visible in the reactor on the 30th day.

[0051] Step 4: The remaining magnetic powder in the reactor is recovered by applying magnets on both sides of the reactor.

[0052] Example 7: Magnetic powder with a concentration of 1.0 g / L and a particle size of 200 nm was used to restore fungal bulking sludge

[0053] Step 1: Prepare a concentrated mother solution with a magnetic powder concentration of 10.0 g / L and a particle size of 200 nm.

[0054] Step 2: When the reactor sludge is uniformly mixed, the mother liquor is introduced into the sludge that has undergone filamentous fungus type swelling, so that the magnetic powder concentration in the reactor reaches 1.0g / L.

[0055] Step 3: Add 2.0 g of 200 nm magnetic powder to the reactor every 10 days. When no filamentous bacteria are visible in the reactor on the 15th day, stop adding.

[0056] Step 4: The remaining magnetic powder in the reactor is recovered by applying magnets on both sides of the reactor.

[0057] Example 8: Magnetic powder with a concentration of 1.0 g / L and a particle size of 10 μm was used to restore fungal bulking sludge

[0058] Step 1: Prepare a concentrated mother solution with a magnetic powder concentration of 10.0 g / L and a particle size of 10 μm.

[0059] Step 2: When the reactor sludge is uniformly mixed, the mother liquor is introduced into the sludge that has undergone filamentous fungus type swelling, so that the magnetic powder concentration in the reactor reaches 1.0g / L.

[0060] Step 3: Add 2.0 g of 10 μm magnetic powder to the reactor every 10 days. When no filamentous bacteria are visible in the reactor on the 25th day, stop adding.

[0061] Step 4: The remaining magnetic powder in the reactor is recovered by applying magnets on both sides of the reactor.

[0062] Example 9: Magnetic powder with a concentration of 1.0 g / L and a particle size of 50 μm was used to restore fungal bulking sludge

[0063] Step 1: Prepare a concentrated mother solution with a magnetic powder concentration of 10.0 g / L and a particle size of 50 μm.

[0064] Step 2: When the reactor sludge is uniformly mixed, the mother liquor is introduced into the sludge that has undergone filamentous fungus type swelling, so that the magnetic powder concentration in the reactor reaches 1.0g / L.

[0065] Step 3: Add 2.0 g of 50 μm magnetic powder to the reactor every 10 days. When no filamentous bacteria are visible in the reactor on the 25th day, stop adding.

[0066] Step 4: The remaining magnetic powder in the reactor is recovered by applying magnets on both sides of the reactor.

Claims

1. A method for recovering filamentous fungus-type expanded halophilic granular sludge using magnetic powder, characterized in that: The steps include: Step 1: Prepare a concentrated mother solution with a magnetic powder concentration of 1.0 to 10.0 g / L; Step 2: When the reactor sludge is uniformly mixed, the mother liquor is introduced into the sludge that has undergone filamentous fungus expansion, so that the magnetic powder concentration in the reactor reaches 0.1-1.0 g / L; Step 3: Add magnetic powder to the reactor every 10 days until there are no filamentous bacteria visible to the naked eye in the reactor, then stop adding; the amount of magnetic powder added is calculated according to the following formula: Where M is the amount of magnetic powder added, g; SRT is the sludge retention time, d; C is the initial concentration of magnetic powder in the reactor, g / L; V is the reactor volume, L; the volume converted to magnetic powder mother liquor is: Where W is the added volume of magnetic powder mother solution, L; M is the added amount of magnetic powder, g; A is the concentration of magnetic powder mother solution; Step 4: The remaining magnetic powder in the reactor is recovered by applying magnets on both sides of the reactor.

2. The method for recovering filamentous fungus-type expanded halophilic granular sludge using magnetic powder according to claim 1, characterized in that: The composition of magnetic powder is Fe3O4, and the particle size is nanometer or micrometer.

Images