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

Abstract

A method for recovering filamentous fugal type expanded salt-tolerant granular sludge by using magnetic powder belongs to the technical field of sewage treatment. The basic principle of the method is to add magnetic powder, use the differential toxicity of magnetic powder to bacteria and fungi, achieve the purpose of inhibiting the proliferation of filamentous fungi, reduce the population number of fungi, and realize the recovery of filamentous fugal type expanded salt-tolerant granular sludge. In this way, the sludge with filamentous fugal type explosive growth can be restored to flocculent structure in a short time, and HAGS with magnetic powder as the core is formed, and the good performance of sewage treatment is recovered. Adding magnetic powder is a physical regulation method without secondary pollution, which is easy to operate and can be attracted by a magnet to realize recycling and reuse. The method has remarkable effect and low cost.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment, specifically a method for restoring filamentous fungal-type expanded halophilic granular sludge using magnetic powder. Background Technology

[0002] Halophilic aerobic granular sludge (HAGS) has proven to be an effective technology for treating high-salt organic wastewater due to its small footprint, excellent pollutant removal capacity, and strong resistance to shock loads. The stability of the granular structure and function is crucial for the long-term stable operation of HAGS. However, recent studies have found that sludge bulking caused by the overgrowth of filamentous fungi occurs in HAGS. This is because filamentous fungi, existing in a skeletal form in HAGS, extend from the core to the granule surface, gain a competitive advantage, and proliferate rapidly. The overgrowth of filamentous fungi leads to a loose granular sludge structure, deteriorated settling ability, microbial loss, and decreased treatment efficiency, affecting the stable operation of HAGS. Therefore, there is an urgent need to propose a method to restore filamentous fungal-induced bulking in HAGS.

[0003] Currently, a common method to inhibit the growth of filamentous microorganisms is to indirectly achieve effective sludge separation through process regulation. Studies have shown that adjusting process parameters such as sludge retention time, nutrient ratio, influent load, and dissolved oxygen concentration can effectively inhibit sludge bulking. However, these methods are time-consuming and costly. Adding physical and chemical agents has been proven to be an effective strategy for inhibiting filamentous microorganisms. Chemical agents are fast-acting and inexpensive, but they increase the risk of recontamination. Physical additives can avoid these risks, but research on them often focuses on the formation of granular sludge, neglecting their potential role in inhibiting the excessive growth of filamentous microorganisms.

[0004] To address the above problems, this patent proposes a method for restoring fungal bulky sludge using magnetic powder. By utilizing the differences in the magnetobiological and toxic effects of magnetic powder on fungi and bacteria, the proliferation of filamentous fungi is inhibited, reducing the fungal population. Summary of the Invention

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

[0006] This invention provides a method for restoring filamentous fungal-type expanded halophilic granular sludge using magnetic powder. The method is characterized by: adding magnetic powder to the fungal-type expanded sludge, utilizing the different magnetobiological and toxic effects of the magnetic powder on fungi and bacteria to inhibit the proliferation of filamentous fungi, reduce the fungal population, and thus restore the fungal-type expanded sludge. Simultaneously, the magnetic powder acts as a nucleus, adsorbing and promoting the attachment and growth of microorganisms, thus fostering the formation of HAGS (Halophyte-Adhesive Granular Globules). The method includes the following steps:

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

[0008] Step 2: When the sludge in the reactor is uniformly mixed, introduce the mother liquor into the sludge that has already undergone filamentous fungal bulking, 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. Continue adding powder until no filamentous bacteria are visible to the naked eye. The amount of magnetic powder to add is calculated using the following formula: Where M is the amount of magnetic powder added, in g; SRT is the sludge retention time, in d; C is the initial concentration of magnetic powder in the reactor, in g / L; and V is the reactor volume, in L. The volume converted to magnetic powder mother liquor is: Where W is the added volume of magnetic powder mother liquor (L); M is the amount of magnetic powder added (g); and A is the concentration of magnetic powder mother liquor.

[0010] Step 4: Recover the remaining magnetic powder in the reactor by applying magnets to both sides of the reactor.

[0011] The technical principle described in this invention is that magnetic powder exerts differential toxicity on fungi and bacteria, leading to differences in their numbers. (See schematic diagram below.) Figure 2 .

[0012] The interfacial interaction between magnetic powder and filamentous fungi leads to membrane penetration, a significant cause of fungal death. Our previous research showed that magnetic powder concentrations of 0.1–1.0 g / L with particle sizes of 200 nm, 10 μm, and 50 μm significantly reduced fungal numbers, but had a smaller impact on bacterial numbers. Adding magnetic powder of the same concentration and particle size significantly inhibited fungal proliferation, resulting in a substantial decrease in fungal numbers and a significant reduction in the proportion of filamentous fungi. The magnetobiological effect of the magnetic powder induces changes in the thermodynamic properties of the sludge surface, thereby enhancing sludge aggregation. Particulate magnetic powder is encapsulated within sludge clusters, where the dominant filamentous fungi, due to their size advantage, capture the magnetic powder using their robust hyphal structures. This increases the contact sites between the filamentous fungi and the magnetic powder, providing favorable conditions for the magnetic powder to penetrate the cell membrane through physical osmosis. Cell membrane rupture is accompanied by cell death, and the cells are expelled with the wastewater. By applying this principle to develop technical methods, the restoration of fungal expanded sludge and the formation of HAGS can be achieved, which provides valuable guidance for the continuous 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 attack bacteria and fungi with differential toxicity, the population of fungi is reduced, and the fungal bulking sludge is restored.

[0015] (2) The magnetic powder added in this invention is an inert material, which does not pose a leaching risk and can be recycled after being attracted by a magnet. Therefore, the external addition of magnetic powder is a green, non-toxic, and environmentally friendly method for controlling sludge bulking.

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

[0017] (4) Magnetic powder has strong adsorption properties. After the fungi are inhibited, the magnetic powder remaining 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 granular sludge in the mature stage, thereby enhancing the stability of granular sludge in long-term stable operation. Attached Figure Description

[0018] Figure 1 Schematic diagram of the reactor

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

[0020] Figure 2 This is a schematic diagram of the invention. Detailed Implementation

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

[0022] Example 1: Magnetic powder with a concentration of 0.1 g / L and a particle size of 200 nm was used to restore fungal bulking sludge.

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

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

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

[0026] Step 4: Recover the remaining magnetic powder in the reactor by applying magnets to both sides of the reactor.

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

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

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

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

[0031] Step 4: Recover the remaining magnetic powder in the reactor by applying magnets to both sides of the reactor.

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

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

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

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

[0036] Step 4: Recover the remaining magnetic powder in the reactor by applying magnets to both sides of the reactor.

[0037] Example 4: Magnetic powder with a concentration of 0.5 g / L and a particle size of 200 nm was added to restore fungal bulking sludge.

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

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

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

[0041] Step 4: Recover the remaining magnetic powder in the reactor by applying magnets to both sides of the reactor.

[0042] Example 5: Magnetic powder with a concentration of 0.5 g / L and a particle size of 10 μm was added to restore fungal bulking sludge.

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

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

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

[0046] Step 4: Recover the remaining magnetic powder in the reactor by applying magnets to 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 added to restore fungal bulking sludge.

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

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

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

[0051] Step 4: Recover the remaining magnetic powder in the reactor by applying magnets to 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 added to restore fungal bulking sludge.

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

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

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

[0056] Step 4: Recover the remaining magnetic powder in the reactor by applying magnets to 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 added to restore fungal bulking sludge.

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

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

[0060] Step 3: Add 2.0g of 10μm magnetic powder to the reactor every 10 days. Stop adding powder when no filamentous bacteria are visible to the naked eye in the reactor on day 25.

[0061] Step 4: Recover the remaining magnetic powder in the reactor by applying magnets to 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 added to restore fungal bulking sludge.

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

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

[0065] Step 3: Add 2.0g of 50μm magnetic powder to the reactor every 10 days. Stop adding powder when no filamentous bacteria are visible to the naked eye in the reactor on day 25.

[0066] Step 4: Recover the remaining magnetic powder in the reactor by applying magnets to both sides of the reactor.

Claims

1. A method for restoring filamentous fungal-type expanded halophilic granular sludge using magnetic powder, characterized in that, Includes the following steps: Step 1: Prepare a concentrated mother liquor with a magnetic powder concentration of 1.0~10.0 g / L; Step 2: Under the condition that the sludge in the reactor is uniformly mixed, the mother liquor is introduced into the sludge that has undergone filamentous fungal bulking, so that the magnetic powder concentration in the reactor reaches 0.1-1.0 g / L; the magnetic powder is composed of Fe3O4 and the particle size is nano- or micro-scale. Step 3: Add magnetic powder to the reactor every 10 days until no filamentous bacteria are visible to the naked eye, then stop adding powder. The amount of magnetic powder to be added is calculated according to the following formula: M = Where M is the amount of magnetic powder added, in g; SRT is the sludge retention time, in d; C is the initial concentration of magnetic powder in the reactor, in g / L; V is the reactor volume, in L; the volume converted to magnetic powder mother liquor is: W = Where W is the volume of magnetic powder mother liquor added (L); M is the amount of magnetic powder added (g); and A is the concentration of magnetic powder mother liquor. Step 4: Recover the remaining magnetic powder in the reactor by applying magnets to both sides of the reactor.

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