Application of bioelectro-Fenton system driven by sulfate reducing strain shewanella in environmental pollutant degradation
By introducing a bioelectric Fenton system driven by the sulfate-reducing strain Shewanella, the problems of slow Fe3+/Fe2+ cycling and high cost in the electro-Fenton technology have been solved, achieving efficient degradation of environmental pollutants, reducing operating costs and improving efficiency.
Patent Information
- Application Number
- CN202610178098.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-08
- Publication Date
- 2026-03-17
AI Technical Summary
Existing electro-Fenton technology faces several challenges in large-scale applications, including high catalyst cost, easy deactivation, electrode scaling and corrosion, limited oxygen mass transfer, high energy consumption, slow Fe3+/Fe2+ circulation and increased operating costs, and quenching of ·OH in complex water matrices, which restrict its engineering advancement.
Introducing biological concepts, a bioelectric Fenton system driven by the sulfate-reducing strain Shewanella is used to achieve efficient degradation of pollutants by generating Fe2+ through the reduction of Fe3+ by hydrogen sulfide, which then reacts with hydrogen peroxide to produce hydroxyl radicals ·OH.
Under aerobic conditions, the hydrogen sulfide generated simultaneously from sulfate ions in the environment participates in the Fenton system, improving the Fe3+/Fe2+ cycle efficiency. This results in low degradation cost, high efficiency, and efficient removal of environmental pollutants.
Smart Images
Figure CN121672747A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of bioelectric Fenton technology, specifically relating to the application of a bioelectric Fenton system driven by sulfate-reducing strain Shewanella in the degradation of environmental pollutants. Background Technology
[0002] Electro-Fenton oxidation, as a highly efficient advanced oxidation technology, has become a research hotspot in wastewater treatment due to its advantage of in-situ generation of H₂O₂ and ·OH to degrade recalcitrant pollutants. Current research focuses on breakthroughs in multiple directions: at the materials level, developing nitrogen-doped carbon-based and single-atom heterogeneous catalysts and modified gas diffusion electrodes, and optimizing 2e⁻. - The selectivity and catalytic stability of the oxygen reduction reaction; at the process level, the construction of a photoelectric and ultrasonic coupling system and a three-dimensional reactor enhances mass transfer efficiency and mineralization capacity, and has shown potential in the treatment of dyeing and pharmaceutical wastewater.
[0003] However, the large-scale application of this technology still faces bottlenecks: the catalyst cost is relatively high and it is prone to dissolution and deactivation under acidic conditions; the electrode is prone to scaling and corrosion during long-term operation; oxygen mass transfer limitations and side reactions lead to low current efficiency and high energy consumption; Fe 3+ / Fe 2+ The slow circulation process increases operating costs. Meanwhile, complex water matrices easily quench ·OH, pilot-scale amplification effects are significant, sludge disposal and secondary pollution are prominent issues, and the interfacial reaction mechanism remains unclear. These problems hinder its engineering advancement and need to be addressed one by one through low-cost material development, reactor optimization, and in-depth understanding of the mechanism.
[0004] Based on this situation, this invention introduces a biological concept into the traditional electro-Fenton device, optimizes the problems existing in the electro-Fenton, and constructs a sulfate-reducing strain-driven bio-electro-Fenton system that can utilize sulfate in the environment to efficiently remove pollutants from the environment. Summary of the Invention
[0005] To solve the problem of Fe in the existing electric Fenton system 3+ / Fe 2+ To address the complex issues such as slow circulation and increased operating costs, this invention proposes an application of a bioelectric Fenton system driven by the sulfate-reducing strain Shewanella in the degradation of environmental pollutants.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0007] An application of a bioelectric Fenton system driven by the sulfate-reducing strain Shewanella in the degradation of environmental pollutants. In the constructed bioelectric Fenton system, hydrogen sulfide produced by the sulfate-reducing strain Shewanella during sulfate reduction participates in the bioelectric Fenton system to achieve the degradation of Fe. 3+ The reduction of Fe produced 2+It reacts with the hydrogen peroxide generated by electrolysis to simultaneously produce hydroxyl radicals (·OH), thereby achieving efficient degradation of environmental pollutants.
[0008] As a preferred technical solution of the present invention, Shewanella oneidensis MR-1 purchased from the American Type Culture Collection (ATCC) is genetically edited to obtain a sulfate-reducing strain of Shewanella capable of reducing sulfate to hydrogen sulfide under aerobic conditions.
[0009] Furthermore, the sulfate-reducing strain Shewanella constructs an aerobic sulfate reduction pathway by heterologously reconstructing a serine acetyltransferase and a cysteine desulfurase resistant to cysteine feedback inhibition, as follows:
[0010] (1) By using gene editing techniques, CysE, which is not affected by the negative feedback inhibition of cysteine, was introduced into the gene. 768 The protein binds to the CdsH protein, which can convert cysteine to H2S, to construct an aerobic sulfate reduction module;
[0011] (2) Genetic construction of the aerobic sulfate reduction module: The cysE gene was cloned from the E. coli genome to construct the shuttle plasmid pBF-cysE; primers were designed to mutate the cysE gene, changing the base G at 768 bp to A, and the shuttle plasmid pBF-cysE was constructed. 768 The cdsH gene was synthesized and integrated into the shuttle plasmid pBF-cysE. 768 Constructing recombinant plasmid pBF-P lac -cdsH-cysE 768 The endogenous promoter gspA of the cdsH gene was removed to obtain the assimilation sulfate reduction module;
[0012] (3) The constructed aerobic sulfate reduction module was introduced into Shewanella MR-1 to obtain an aerobic sulfate reduction engineered strain.
[0013] As a preferred technical solution of the present invention, the sulfate-reducing strain Shewanella is inoculated into LB medium and cultured by shaking to obtain a bacterial solution; the bacterial solution is frozen and centrifuged and then added to a simulated wastewater medium; then environmental pollutants are added to the medium, and carbon paper is used as the cathode and anode, with an external DC power supply connected to both ends of the medium.
[0014] Furthermore, the simulated wastewater culture medium is formulated as follows: 60% L-lactic acid sodium solution (18 mM), ammonium chloride (28 mM), potassium chloride (1.3 mM), sodium dihydrogen phosphate dihydrate (4.3 mM), sodium chloride (100 mM), sodium hydroxide (7.5 mM), MgSO4 (2 mM), ferric citrate (5 mM), and Na2SO4 (100 mM).
[0015] This invention proposes an application of a bioelectric Fenton system driven by the sulfate-reducing strain Shewanella in the degradation of environmental pollutants. It can efficiently utilize the ubiquitous sulfate ions in the environment, and the hydrogen sulfide generated simultaneously participates in the Fenton system. The hydroxyl radicals generated thereby achieve efficient removal of pollutants from the environment, with no pollution, low degradation cost, and high efficiency.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0017] This invention constructs a Sheva strain capable of reducing sulfate under aerobic conditions, utilizing the hydrogen sulfide it produces to participate in the Fe in the Fenton system. 3+ / Fe 2+ By incorporating a cyclical process, this method significantly addresses the issue of slow operation. Compared to traditional electro-Fenton systems, it introduces a biological concept. While addressing the large amount of sulfate ions present in the environment, hydrogen sulfide is simultaneously generated and participates in the Fenton system. The resulting hydroxyl radicals can efficiently remove pollutants from the environment. Therefore, this technology utilizes the abundant sulfate ions in the environment while improving the operating efficiency of the electro-Fenton system, effectively removing pollutants. Attached Figure Description
[0018] Figure 1 A schematic diagram of a novel bioelectric Fenton system driven by sulfate-reducing strains (the simulated pollutant in the beaker is Rhodamine B).
[0019] Figure 2 The full spectrum of the degradation of pollutant Direct Black 168.
[0020] Figure 3 The color change of the solution at different times during the degradation process of the pollutant Direct Black 168.
[0021] Figure 4 This is the standard curve for the pollutant bisphenol A.
[0022] Figure 5 The degradation curve of the pollutant bisphenol A is shown. Detailed Implementation
[0023] like Figure 1As shown, this invention proposes a bioelectric Fenton system driven by the sulfate-reducing strain Shewanella, and applies it to the degradation of environmental pollutants. In this constructed bioelectric Fenton system, hydrogen sulfide produced by the sulfate-reducing strain Shewanella during sulfate reduction participates in the bioelectric Fenton system to achieve the degradation of Fe. 3+ The reduction of Fe produced 2+ It reacts with the hydrogen peroxide generated by electrolysis to simultaneously produce hydroxyl radicals (·OH), thereby achieving efficient degradation of environmental pollutants.
[0024] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings.
[0025] Example 1
[0026] Removal of Direct Black 168, a common dye contaminant in the environment:
[0027] (1) Prepare the simulated wastewater culture medium as follows:
[0028] The solution contains 60% L-lactic acid sodium (18 mM), ammonium chloride (28 mM), potassium chloride (1.3 mM), sodium dihydrogen phosphate dihydrate (4.3 mM), sodium chloride (100 mM), sodium hydroxide (7.5 mM), MgSO4 (2 mM), ferric citrate (5 mM), and Na2SO4 (100 mM), with a total solution volume of 100 mL.
[0029] (2) Direct Black was added to the culture medium as a model pollutant, with a final concentration of 40 mg / L.
[0030] (3) Transfer the above simulated wastewater culture medium to a 200 mL beaker and seal it with sealing film for later use.
[0031] (4) Strains used: Shewanella oneidensis MR-1, purchased from the American Type Culture Collection (ATCC), strain number ATCC700550. After gene editing, a sulfate-reducing strain of Shewanella was obtained, which is capable of reducing sulfate to hydrogen sulfide under aerobic conditions.
[0032] (5) Obtaining Shewanella bacterial culture: Sulfate-reducing strain Shewanella was inoculated into 100 mL of LB medium (containing 5 g / L yeast extract, 10 g / L tryptone and 10 g / L sodium chloride, pH=7) and cultured at 30℃ and 200 rpm for 12 h to obtain bacterial culture.
[0033] (6) Centrifuge the bacterial solution at 5000 rpm and add it to the simulated wastewater culture medium. Use carbon paper as the cathode and anode, and connect an external DC power supply at both ends of the culture medium. The working voltage is 1.5V. Meanwhile, another group does not add bacterial solution as a control group.
[0034] (7) After the experiment started, samples were taken every 24 hours, and the changes in the characteristic absorption peak of the pollutant Direct Black 168 were detected using an ultraviolet spectrophotometer.
[0035] like Figure 2 As shown, the characteristic absorption peak of Direct Black 168 at 623 nm gradually decreases over time, and the peak shape changes significantly. Simultaneously, it is clearly visible that Direct Black 168 undergoes significant decolorization over time. Figure 3 As shown in the figure, this indicates that the expected reaction occurred, namely, the sulfate-reducing strain Shewanella achieved efficient reduction of sulfate, and the generated hydrogen sulfide participated in the bio-Fenton system to achieve the reduction of Fe. 3+ The reduction of Fe produced 2+ It reacts with the hydrogen peroxide generated by electrolysis to simultaneously produce hydroxyl radicals (·OH), thereby achieving efficient degradation of the environmental pollutant Direct Black 168.
[0036] Example 2
[0037] Removal of Bisphenol A, a common dye pollutant in the environment:
[0038] (1) Prepare the simulated wastewater culture medium as follows:
[0039] The solution contains 60% L-lactic acid sodium (18 mM), ammonium chloride (28 mM), potassium chloride (1.3 mM), sodium dihydrogen phosphate dihydrate (4.3 mM), sodium chloride (100 mM), sodium hydroxide (7.5 mM), MgSO4 (2 mM), ferric citrate (5 mM), and Na2SO4 (100 mM), with a total solution volume of 100 mL.
[0040] (2) Bisphenol A was added to the culture medium as a model pollutant, with a final concentration of 5 mg / L.
[0041] (3) Transfer the above simulated wastewater culture medium to a 200 mL beaker and seal it with sealing film for later use.
[0042] (4) Strains used: Shewanella oneidensis MR-1, purchased from the American Type Culture Collection (ATCC), strain number ATCC700550. After gene editing, a sulfate-reducing strain of Shewanella was obtained, which is capable of reducing sulfate to hydrogen sulfide under aerobic conditions.
[0043] (5) Obtaining Shewanella bacterial culture: Sulfate-reducing strain Shewanella was inoculated into 100 mL of LB medium (containing 5 g / L yeast extract, 10 g / L tryptone and 10 g / L sodium chloride, pH=7) and cultured at 30℃ and 200 rpm for 12 h to obtain bacterial culture.
[0044] (6) Centrifuge the bacterial solution at 5000 rpm and add it to the simulated wastewater culture medium. Use carbon paper as the cathode and anode, and connect an external DC power supply at both ends of the culture medium. The working voltage is 1.5V as the experimental group. At the same time, another group does not add bacterial solution as the control group.
[0045] (7) After the experiment started, samples were taken every 12 hours. Sampling was stopped after 7 days. The concentration change of the pollutant bisphenol A was detected by ultra-high performance liquid chromatography.
[0046] Figure 4 The BPA standard curve was measured using ultra-high performance liquid chromatography (UHPLC), with a detection limit of 1 ug / L. From... Figure 5 It can be seen that, compared with the control group, the experimental group only achieved the removal of bisphenol A (BPA) as a model pollutant in the presence of Shewanella bacteria. This indicates that the sulfate-reducing strain of Shewanella efficiently reduced sulfate, and the resulting hydrogen sulfide participated in the bio-Fenton system to remove Fe. 3+ The reduction of Fe produced 2+ It then reacts with the hydrogen peroxide generated by electrolysis to simultaneously produce hydroxyl radicals (·OH), thereby achieving efficient degradation of the environmental pollutant bisphenol A.
[0047] Examples 1 and 2 both demonstrate the good removal effect of the present invention on common pollutants in the environment.
Claims
1. Use of a bio-electro-Fenton system driven by a strain of sulphate-reducing bacteria Shewanella in the degradation of environmental pollutants, characterized in that, In the constructed bio-electro-Fenton system, the hydrogen sulfide produced by the sulfate-reducing bacteria strain Shewanella reduces the Fe 3+ , and the produced Fe 2+ reacts with the hydrogen peroxide generated by electrolysis to produce hydroxyl radicals simultaneously, thereby achieving efficient degradation of environmental pollutants.
2. Use according to claim 1, wherein Shewanella oneidensis MR-1 purchased from the American Type Culture Collection (ATCC) is genetically edited to obtain a sulfate-reducing bacterial strain Shewanella with the ability to reduce sulfate to hydrogen sulfide under aerobic conditions.
3. Use according to claim 2, wherein the compound is ###0002### The sulfate-reducing bacterial strain Shewanella is constructed by heterologous reconstruction of cysteine feedback-resistant serine acetyltransferase and cysteine desulfurase to construct an aerobic sulfate reduction pathway, and the steps are as follows: (1) By gene editing means, CysE protein which is not affected by cysteine negative feedback inhibition is combined with CdsH protein which can convert cysteine to H2S to construct an aerobic sulfate reduction module; 768 protein which is not affected by cysteine negative feedback inhibition is combined with CdsH protein which can convert cysteine to H2S to construct an aerobic sulfate reduction module; (2) Genetic construction of aerobic sulfate reduction module: The cysE gene was cloned from the E. coli genome to construct the shuttle plasmid pBF-cysE; the primer pair was designed to mutate the cysE gene, and the base G at 768 bp was mutated to A to construct the shuttle plasmid pBF-cysE 768 ; the cdsH gene was synthesized and integrated into the shuttle plasmid pBF-cysE 768 , to construct the recombinant plasmid pBF-P lac -cdsH-cysE 768 , and the endogenous promoter gspA of the cdsH gene was removed to obtain the assimilatory sulfate reduction module; (3) The constructed aerobic sulfate reduction module is introduced into Shewanella MR-1 to obtain an aerobic sulfate reduction engineering strain.
4. The use according to claim 2, wherein The sulfate-reducing bacterial strain Shewanella is inoculated into LB culture medium and shaken to obtain a bacterial solution; the bacterial solution is frozen and centrifuged and then added into a simulated wastewater culture medium; then, environmental pollutants are added into the culture medium, and carbon paper is used as anode and cathode, and a direct current power supply is connected to both ends of the culture medium.
5. The use according to claim 4, wherein the compound is ###0002### The formula of the simulated wastewater culture medium is as follows: L-sodium lactate 60% solution (18 mM), ammonium chloride (28 mM), potassium chloride (1.3 mM), sodium dihydrogen phosphate dihydrate (4.3 mM), sodium chloride (100 mM), sodium hydroxide (7.5 mM), MgSO4 (2 mM), ferric citrate (5 mM), and Na2SO4 (100 mM).