A method for improving the metabolic activity of sulfur dismutase bacteria by applying an external static magnetic field

Abstract

The present invention discloses a method for improving the metabolic activity of sulfur disproportionation bacteria by applying an external static magnetic field, comprising the following steps: in an anoxic or anaerobic environment, inoculating sludge containing sulfur disproportionation bacteria into a reaction tank, and adding elemental sulfur as a disproportionation matrix; under suitable temperature, alkalinity and pH, applying an external static magnetic field to the reaction tank to promote the enhancement of the metabolic activity of sulfur disproportionation bacteria. The static magnetic field is used to induce the sulfur disproportionation bacteria to produce a magnetic biological effect, improve enzyme activity and cell membrane permeability, thereby accelerating the absorption and utilization of nutrients and elemental sulfur by the sulfur disproportionation bacteria, enhancing the metabolic activity of the sulfur disproportionation bacteria, and promoting the sulfur disproportionation bacteria to more efficiently utilize S 0 The method not only solves the problem of low efficiency of sewage / wastewater treatment process caused by low metabolic activity of sulfur disproportionating bacteria, but also reduces secondary pollution, saves costs, and has good environmental and economic benefits.

Description

Technical Field

[0001] The invention relates to the field of water treatment, and in particular to a method for improving the metabolic activity of sulfur disproportionate bacteria by applying an external static magnetic field. Background Art

[0002] In recent years, biosulfurization (S 2- ) production process has attracted much attention due to its low energy consumption, low cost and high efficiency. The formation of sulfide can not only act as an electron donor to reduce nitrate to achieve denitrification, but also form metal sulfide precipitation with heavy metal ions to remove heavy metals in water.

[0003] Common biological sulfur production methods include sulfate reduction and elemental sulfur reduction. The main principle is sulfate-reducing bacteria (SRB) or elemental sulfur-reducing bacteria (S 0 RB) uses organic carbon as an electron donor to convert SO4 2- / S 0 Reduced to sulfide. Compared with sulfate reduction, elemental sulfur reduction can save 3 / 4 of the electron donor. However, heavy metal-containing wastewater usually lacks organic carbon, so additional organic matter is still required to drive the biological sulfur reduction process to produce sulfide, which brings about the problem of increased operating costs and carbon emissions.

[0004] Compared with the sulfur production process mediated by heterotrophic sulfur-reducing bacteria, autotrophic sulfur-disproportionating bacteria (SDB) can simultaneously oxidize and reduce sulfur-containing compounds in the intermediate valence state to sulfate and sulfide. This process does not require the participation of organic carbon, avoiding the risk of secondary environmental pollution caused by the addition of carbon sources. In theory, it can further reduce the cost of heavy metal wastewater treatment. Elemental sulfur is not easily soluble in water and will not be lost with water during wastewater treatment. Therefore, the sulfur production process based on elemental sulfur disproportionation has a wider application prospect. The reaction equation is as follows: However, the Gibbs free energy of this reaction is positive, indicating that S 0 The disproportionation reaction is not easy to occur.

[0005] It is reported that the sulfur dismutation reaction occurs at a low level and the metabolic activity is much lower than that of the sulfur reduction process. Moreover, sulfur dismutation bacteria are autotrophic organisms with a long generation time, e.g. Sulfurimonas sp.ST-27 and SulfurovumThe doubling time of the two sulfur disproportionation strains of sp.ST-29 was 2.4 d and 1.9 d, respectively. The low metabolic activity and long generation time of sulfur disproportionation bacteria are not conducive to the practical application of sulfur production technology based on biological sulfur disproportionation. Therefore, it is of practical importance to improve the metabolic activity of sulfur disproportionation bacteria. Summary of the invention

[0006] In order to overcome the deficiencies of the above prior art, the purpose of the present invention is to provide a method for increasing the metabolic activity of sulfur disproportionate bacteria by applying an external static magnetic field, thereby solving the problem of low metabolic activity of sulfur disproportionate bacteria and accelerating the sulfur disproportionation reaction to produce sulfide.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A method for improving the metabolic activity of sulfur disproportionate bacteria by applying an external static magnetic field comprises the following steps:

[0009] (1) In an anoxic or anaerobic environment, sludge containing sulfur disproportionating bacteria is inoculated into the reaction tank, and elemental sulfur is added as the disproportionating substrate;

[0010] (2) Under suitable temperature, alkalinity and pH, a static magnetic field is applied outside the reaction tank to enhance the metabolic activity of sulfur dismutase bacteria.

[0011] Preferably, the static magnetic field is provided by a permanent magnet, and the strength of the static magnetic field is 10-200 MT.

[0012] Preferably, the strength of the static magnetic field is 50-130 MT.

[0013] Preferably, the material of the permanent magnet includes one of neodymium iron boron, aluminum nickel cobalt, ferrite, cobalt magnet or manganese borate.

[0014] Preferably, the sulfur disproportionating bacteria refer to bacteria or archaea that can undergo sulfur disproportionation reaction using intermediate valence sulfur-containing compounds as electron donors and acceptors, use inorganic carbon as a carbon source for life activities, and can survive in a variety of environments.

[0015] Preferably, the sulfur dismutating bacteria include Dissulfurimicrobium, Desulfobulbus, Desulfofustis, Desulfurella, Desulfurivibrio Genus and Dissulfuribacter Belong.

[0016] Preferably, the temperature is 18-65°C.

[0017] Preferably, the alkalinity is 0.5-5 g / L (in terms of CaCO3).

[0018] Preferably, the pH is 6.5-9.0.

[0019] Preferably, the sludge containing sulfur disproportionate bacteria is inoculated sludge after directional domestication for 15-30 days.

[0020] Preferably, the inoculated sludge comprises one or more of sewage treatment plant sludge, estuarine sediments, marine sediments, soil or riverbed sludge.

[0021] Preferably, it is applied to reduce nitrate to achieve denitrification, removal of heavy metals in water bodies or reduction and removal of oxidative pollutants.

[0022] The present invention has the following advantages and beneficial effects compared with the prior art:

[0023] (1) The present invention utilizes an external magnetic field to induce the intrinsic biomagnetic effect of sulfur dismutase bacteria, thereby enhancing enzyme activity and cell membrane permeability, thereby increasing the sulfur production rate of sulfur dismutase bacteria, helping to promote the application of sulfur dismutase bacteria in heavy metal wastewater treatment, achieving low-carbon and high-efficiency heavy metal removal, and can also be used to reduce nitrates to achieve denitrification and reduce and remove oxidative pollutants.

[0024] (2) The present invention accelerates the process of producing sulfide by sulfur disproportionation biochemical reaction by adding a static magnetic field of appropriate strength to the outside of the reaction tank to enhance the activity of sulfur disproportionation bacteria. The static magnetic field formed by using permanent magnets has many advantages such as no secondary pollution, no need for additional energy, cost saving, easy management and operation, etc. It provides a green and effective solution to the problem of low efficiency of sewage / wastewater treatment process caused by low metabolic activity of sulfur disproportionation bacteria, and is expected to develop the biological sulfur disproportionation process into a low-carbon, efficient and economic sewage / wastewater treatment technology.

[0025] The principle of the present invention is:

[0026] The intrinsic magnetism of sulfur disproportionating microorganisms can show magnetic biological effects under the induction of an external magnetic field of appropriate strength, affecting enzyme activity and cell membrane permeability, and further affecting the uptake and utilization of nutrients and elemental sulfur by sulfur disproportionating bacteria, thus changing the metabolic conversion of microorganisms. 0 In addition, static magnetic fields of appropriate intensity can also promote biochemical reactions such as cell division, cell movement and electron transfer of microorganisms. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Graph showing the change in average concentration of sulfide produced over time in each embodiment of the present invention.

[0028] Figure 2 This is a curve chart showing the change of the sulfide production enhancement rate over time in Example 2-3 of the present invention. DETAILED DESCRIPTION

[0029] The purpose of the present invention is further described in detail below with reference to the accompanying drawings and specific examples. The examples cannot be described one by one here, but the implementation methods of the present invention are not therefore limited to the following examples.

[0030] Example 1

[0031] After 15 days of targeted acclimatization and cultivation of sludge containing sulfur disproportionate bacteria from a sewage treatment plant, it was inoculated into a reaction tank and washed three times with deoxygenated water to completely remove the residual soluble sulfide. The alkalinity in the reaction tank was set to 0.5 g / L, pH to 8.0 ± 0.2, elemental sulfur concentration to 1 g / L, and temperature to 22 ± 2°C. The sulfur disproportionate bacteria performed the following reactions in the reaction tank: , elemental sulfur undergoes redox reaction to form sulfide and sulfate. The reaction pool of this embodiment does not have an external static magnetic field. The concentration of sulfide in the reaction pool is detected every 2 hours. The detection method is the national standard (HJ 1226-2021) methylene blue spectrophotometry.

[0032] Example 2

[0033] Except for the following technical features, the other technical features of this embodiment are the same as those of the first embodiment:

[0034] A permanent magnet is used outside the reaction cell to generate a static magnetic field with an intensity of 50 MT.

[0035] Example 3

[0036] Except for the following technical features, the other technical features of this embodiment are the same as those of the first embodiment:

[0037] A permanent magnet is used outside the reaction cell to generate a static magnetic field with an intensity of 130 MT.

[0038] Figure 1 is a curve diagram showing the average concentration of sulfide produced in each embodiment changing with time, Figure 1 It can be seen that during the entire experiment, the sulfide production rate in the reactor without adding a static magnetic field was 12.14 mg S / (L·h), which was lower than the sulfide production rates with an external static magnetic field of 50 MT and 130 MT, which were 16.15 mg S / (L·h) and 20.54 mg S / (L·h), respectively. After 8 hours of reaction, the sulfide concentration without a magnetic field was 101.25 mg S / L, while the sulfide concentration in the presence of a static magnetic field of 130 MT was 132.25 mg S / L, an increase of about 30.62%.

[0039] Figure 2 is the curve of the change of the sulfide production enhancement rate over time in Example 2-3, Figure 2It can be seen that the enhancement rate of sulfide production under a static magnetic field of 50 MT is always greater than 9%, while the enhancement rate of sulfide production under a static magnetic field of 130 MT is greater than 30.62%, and the maximum enhancement rate can reach 45.30%, which is much higher than the enhancement rate of sulfide production under a static magnetic field of 50 MT.

[0040] In short, when the static magnetic field is added, the rate of sulfide production is significantly accelerated, and the rate of sulfide production increases with the increase of the static magnetic field, indicating that the addition of the static magnetic field is conducive to the enhancement of the metabolic activity of sulfur disproportionation bacteria and the reaction rate of elemental sulfur disproportionation. The addition of the magnetic field accelerates the production of sulfide, and sulfide can combine with metal ions such as copper ions, lead ions, and mercury ions to form insoluble metal sulfide precipitates, thereby removing these metal ions and achieving the effect of purifying sewage. The increase in the rate of sulfide production is helpful to promote the development and application of sulfur disproportionation technology.

[0041] The above specific implementation modes are preferred embodiments of the present invention and cannot be used to limit the present invention. Any other changes or other equivalent replacement methods that do not deviate from the technical solution of the present invention are included in the protection scope of the present invention.

Claims

1. A method for increasing the metabolic activity of sulfur disproportionate bacteria by applying an external static magnetic field, characterized in that: The following steps are involved: (1) In an anoxic or anaerobic environment, sludge containing sulfur disproportionating bacteria is inoculated into the reaction tank, and elemental sulfur is added as the disproportionating substrate; (2) applying a static magnetic field outside the reaction tank at a suitable temperature, alkalinity and pH to enhance the metabolic activity of sulfur dismutase bacteria; The sludge containing sulfur disproportionate bacteria is inoculated sludge after directional domestication for 15-30 days; The intensity of the static magnetic field is 50-130 MT; The temperature is 18-65°C; The alkalinity is 0.5-5 g / L; The pH is 6.5~9.

0.

2. The method for improving the metabolic activity of sulfur dismutase bacteria by applying an external static magnetic field according to claim 1, characterized in that: The static magnetic field is provided by permanent magnets.

3. The method for improving the metabolic activity of sulfur disproportionate bacteria by applying an external static magnetic field according to claim 2, characterized in that: The material of the permanent magnet includes one of neodymium iron boron, aluminum nickel cobalt, ferrite, cobalt magnet or manganese borate.

4. The method for improving the metabolic activity of sulfur disproportionate bacteria by applying an external static magnetic field according to claim 1, characterized in that: The inoculated sludge includes one or more of sludge from a sewage treatment plant, estuary sediment, marine sediment, soil or riverbed sludge.

5. The method for improving the metabolic activity of sulfur disproportionate bacteria by applying an external static magnetic field according to claim 1, characterized in that: It is used to reduce nitrate to achieve denitrification or remove heavy metals in water.

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