Application of a composite hybrid based on non-oxygenic photosynthetic bacteria in simultaneous carbon sequestration and degradation of toxic and refractory organic pollutants

Abstract

The application belongs to the technical field of water pollution treatment, and particularly relates to application of a composite hybrid based on non-oxygen-producing photosynthetic bacteria in simultaneous carbon sequestration and degradation of toxic and refractory organic pollutants. The composite hybrid based on non-oxygen-producing photosynthetic bacteria provided in the application can synergize nano ferrihydrite, nano calcium carbonate and marsh Rhodopseudomonas spheroides, degrade organic pollutants and sequester carbon through multiple pathways, and generate valuable resources; meanwhile, the nano ferrihydrite / nano calcium carbonate / marsh Rhodopseudomonas spheroides / natural conductive polymer hybrid can be loaded on a fiber brush by using a natural conductive polymer, so that the marsh Rhodopseudomonas spheroides rich in valuable resources such as proteins and photosynthetic pigments can be more easily recovered, thereby solving the technical problems of poor effect of degrading toxic and refractory organic pollutants and high carbon emission in the process of purifying wastewater containing organic pollutants in the prior art.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of water pollution treatment, and particularly relates to application of a composite hybrid based on non-oxygen-producing photosynthetic bacteria in simultaneous carbon sequestration and degradation of toxic and refractory organic pollutants. BACKGROUND

[0002] Pharmaceutical and personal care products (PPCPs) include antibiotics, anti-inflammatory drugs, cosmetics, cleaning and care products, and the like. With the development of society, the types and usage of pharmaceutical and personal care products (PPCPs) are increasing year by year. However, pharmaceutical and personal care products (PPCPs) have potential biological accumulation and biological toxicity, especially antibiotics, which are prone to produce resistance genes. As therapeutic drugs, antibiotics often enter water systems directly through feces, urine and other excrement without complete metabolism, causing water pollution and seriously threatening human health and ecological safety.

[0003] At present, the purification treatment methods for wastewater mainly include physical treatment, chemical treatment and biological treatment. Physical treatment mainly removes suspended solids and part of macromolecular organic matter through filtration, sedimentation and adsorption, and is difficult to purify and treat dissolved organic pollutants such as antibiotics. Chemical treatment mainly uses various chemical agents to react with pollutants to make them coagulate and precipitate, oxidize and reduce. However, the chemical agents used in chemical treatment usually have high cost and complex operation, and the chemical agents are prone to secondary pollution. Biological treatment mainly uses activated sludge method and biofilm method to treat pollutants that are easy to degrade, and has limited effect on organic pollutants such as antibiotics. In addition, during the process of degrading organic pollutants by biological treatment, a large amount of CO2 is directly released into the atmosphere during the oxidation process when organic carbon is degraded by microorganisms. Especially when treating wastewater containing high-concentration organic matter, the carbon emission is more significant. Incomplete nitrification and denitrification of microorganisms can easily lead to the emission of nitrous oxide (N2O) into the atmosphere, which is a greenhouse gas causing carbon emission. The ability of some microorganisms to assimilate and absorb carbon, nitrogen and other elements and convert them into biomass can not only reduce carbon emission but also recover valuable resources.

[0004] It is urgent to develop and apply low-carbon or even zero-carbon water pollution treatment technology to reduce direct or indirect emission of greenhouse gases and generate valuable resources, which has important application value. SUMMARY

[0005] Therefore, the application provides application of a composite hybrid based on non-oxygen-producing photosynthetic bacteria in simultaneous carbon sequestration and degradation of toxic and refractory organic pollutants, which is used to solve the technical problem that the effect of degrading organic pollutants is not good and carbon emission is easy to occur in the process of purifying wastewater containing organic pollutants in the prior art.

[0006] The first aspect of the present application provides a composite hybrid based on anoxygenic photosynthetic bacteria, which comprises nanoferrihydrite, nanocalcium carbonate and Rhodopseudomonas palustris.

[0007] The nanocalcium carbonate and Rhodopseudomonas palustris adhere to the surface of the nanoferrihydrite.

[0008] Preferably, the composite hybrid based on anoxygenic photosynthetic bacteria further comprises a natural conductive polymer.

[0009] The nanocalcium carbonate and Rhodopseudomonas palustris adhere to the surface of the nanoferrihydrite through the natural conductive polymer.

[0010] Preferably, the natural conductive polymer is a conductive alginate-based polymer.

[0011] Preferably, the mass ratio of sodium alginate to calcium sulfate in the raw materials used to form the conductive alginate-based polymer is 1:0.1-0.2.

[0012] Preferably, the particle size of the nanoferrihydrite is 100-500 nm.

[0013] The particle size of the nanocalcium carbonate is 20-100 nm.

[0014] Preferably, the particle size of the nanoferrihydrite is 200-400 nm.

[0015] The particle size of the nanocalcium carbonate is 30-50 nm.

[0016] The second aspect of the present application provides a preparation method of the composite hybrid based on anoxygenic photosynthetic bacteria according to the first aspect, which comprises the following steps:

[0017] Step A1, adding nanoferrihydrite and nanocalcium carbonate to a Rhodopseudomonas palustris cell suspension and stirring to obtain a preliminarily combined nanoferrihydrite / nanocalcium carbonate / Rhodopseudomonas palustris hybrid suspension;

[0018] Step A2, co-culturing the preliminarily combined nanoferrihydrite / nanocalcium carbonate / Rhodopseudomonas palustris hybrid suspension under light, and performing solid-liquid separation to obtain a nanoferrihydrite / nanocalcium carbonate / Rhodopseudomonas palustris hybrid.

[0019] Step A3, adding the nanoferrihydrite / nanocalcium carbonate / Rhodopseudomonas palustris hybrid to a natural polymer salt solution, fully stirring, and then performing ion crosslinking to obtain the composite hybrid based on anoxygenic photosynthetic bacteria.

[0020] Preferably, in step A1, the concentration of the Rhodopseudomonas palustris cell suspension is 9x10 8 ~ 3x10 9 cell L -1 .

[0021] Preferably, in step A1, the mass-volume ratio of the nanogoethite, nanocalcium carbonate and Rhodopseudomonas palustris cell suspension is 0.2-0.8 g:0.2 g:1 L.

[0022] Preferably, in step A1, the stirring speed is 100-200 rpm and the stirring time is 1-2 h.

[0023] Preferably, in step A2, the light intensity of the co-culture is 10000-60000 lx, the wavelength is 580-700 nm, and the time is 12-36 h.

[0024] Preferably, in step A2, the solid-liquid separation process is centrifugation at a speed of 5000 rpm for 30 min.

[0025] Preferably, in step A3, the mass-volume ratio of the natural high molecular salt solution is 1-3%.

[0026] The third aspect of the present application provides a composite hybrid carbon brush based on non-oxygenic photosynthetic bacteria, comprising: a fiber brush, a natural conductive polymer and the composite hybrid based on non-oxygenic photosynthetic bacteria of the first aspect.

[0027] The composite hybrid based on non-oxygenic photosynthetic bacteria of the first aspect is adhered and fixed on the surface of the bristles of the fiber brush by the conductive polymer hydrogel.

[0028] Preferably, the natural conductive polymer is a conductive alginate-based polymer.

[0029] The fourth aspect of the present application provides a preparation method of the composite hybrid carbon brush based on non-oxygenic photosynthetic bacteria of the third aspect, and the preparation method comprises:

[0030] Step B1, soaking the conductive alginate-based polymer in a 100 mM excess CaCl2 solution for 1 day to obtain rehydrated hydrogel;

[0031] Step B2, adding the composite hybrid based on non-oxygenic photosynthetic bacteria of the first aspect or the second aspect to the rehydrated hydrogel to obtain a conductive polymer / hybrid mixture suspension;

[0032] Step B3, impregnating or spraying the polymer / hybrid mixture suspension to the surface of the bristles of the fiber brush, and solidifying to obtain a composite hybrid carbon brush based on non-oxygenic photosynthetic bacteria.

[0033] The fifth aspect of the present application provides the application of the composite hybrid body based on anoxygenic photosynthetic bacteria or the carbon brush of the composite hybrid body based on anoxygenic photosynthetic bacteria in the simultaneous carbon sequestration and degradation of toxic and refractory organic pollutants.

[0034] Preferably, the application of the composite hybrid body based on anoxygenic photosynthetic bacteria or the carbon brush of the composite hybrid body based on anoxygenic photosynthetic bacteria in the simultaneous carbon sequestration and degradation of organic pollutants specifically includes: adding the composite hybrid body based on anoxygenic photosynthetic bacteria or the carbon brush of the composite hybrid body based on anoxygenic photosynthetic bacteria to the wastewater containing sulfadiazine, and carrying out the simultaneous carbon sequestration and degradation of toxic and refractory organic pollutants under light.

[0035] Compared with the prior art, the application of the composite hybrid body based on anoxygenic photosynthetic bacteria in the simultaneous carbon sequestration and degradation of toxic and refractory organic pollutants at least includes the following beneficial effects.

[0036] 1. In the composite hybrid body based on anoxygenic photosynthetic bacteria provided by the present application, nano-goethite can promote the photo-heterotrophic metabolism of Rhodopseudomonas palustris, the extracellular secretion of photosensitive active substances, the synthesis of adenosine triphosphate (ATP), and the formation of goethite conductive bands. After the organic carbon source in the wastewater is depleted, nano-calcium carbonate can be slowly dissolved into bicarbonate under the action of the metabolic acid produced by Rhodopseudomonas palustris, serving as a carbon source for the photoautotrophy of Rhodopseudomonas palustris, thereby realizing the recycling of Fe 3+ reduced by the photoautotrophic process of Rhodopseudomonas palustris 2+ to Fe 3+ , and the recycling of Fe 2+ / Fe 3+ , and the recycling of Fe 3+ , thereby realizing the continuous driving of the photoautotrophic process of Rhodopseudomonas palustris and the photo-bio-electro-chemical enhanced carbon sequestration and antibiotic degradation. This makes the nano-goethite / nano-calcium carbonate / Rhodopseudomonas palustris / naturally conductive polymer hybrid body provided by the present application have the effect of enhancing the degradation of organic pollutants, carbon sequestration, and the generation of valuable resources through multiple pathways.

[0037] 2. In the composite hybrid body based on anoxygenic photosynthetic bacteria provided by the present application, by controlling the concentrations of Rhodopseudomonas palustris, nano-goethite, and nano-calcium carbonate during the preparation process, the effect of enhancing the degradation of organic pollutants, carbon sequestration, and the generation of valuable resources is further strengthened.

[0038] 3. The composite hybrid body based on anoxygenic photosynthetic bacteria provided by the present application can also be carbonized with a fiber brush, which is suitable for treating organic pollutants in wastewater with strong water flow and is easy to recover valuable resources. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the drawings needed to be used in the description of the specific embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0040] Figure 1 The scanning electron microscope images of the nanometer ferrihydrite, the scanning electron microscope images of the Rhodopseudomonas palustris, the scanning electron microscope images of the composite hybrid based on the anoxygenic photosynthetic bacteria, and the transmission electron microscope images of the composite hybrid based on the anoxygenic photosynthetic bacteria provided for Embodiment 1 of the present application;

[0041] Figure 2 The schematic diagram of the removal rate and kinetics of sulfadiazine (SDZ) in simulated wastewater degraded by a composite hybrid based on anoxygenic photosynthetic bacteria, nanometer ferrihydrite, and Rhodopseudomonas palustris under light or dark conditions provided for Embodiment 1 of the present application;

[0042] Figure 3 The schematic diagram of different degradation pathways of sulfadiazine (SDZ) in simulated wastewater by a composite hybrid based on anoxygenic photosynthetic bacteria provided for Embodiment 1 of the present application;

[0043] Figure 4 The schematic diagram of the amount of CO2 generated in the process of degrading sulfadiazine (SDZ) in simulated wastewater by a composite hybrid based on anoxygenic photosynthetic bacteria, nanometer ferrihydrite, and Rhodopseudomonas palustris with different concentrations under light or dark conditions provided for Embodiments 1-3 of the present application. DETAILED DESCRIPTION

[0044] The present application provides an application of a composite hybrid based on anoxygenic photosynthetic bacteria in simultaneous carbon sequestration and degradation of toxic and refractory organic pollutants, which is used to solve the technical problem that the effect of degrading organic pollutants is not good and carbon emission is easy to occur in the process of purifying wastewater containing organic pollutants in the prior art.

[0045] The technical solutions of the present application will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0046] In view of the defects that the treatment effect of organic pollutants such as antibiotics is not good and carbon emission is easy to occur in the process of purifying wastewater containing organic pollutants such as antibiotics by using biological treatment and the like at present, the application provides a composite hybrid body based on non-oxygen-producing photosynthetic bacteria, that is, a nano-hydro ferrite / nano-calcium carbonate / marsh red false single-celled bacteria / natural high polymer hybrid body; the composition comprises nano-hydro ferrite, nano-calcium carbonate and marsh red false single-celled bacteria, and the marsh red false single-celled bacteria and the nano-calcium carbonate are adhered to the surface of the nano-hydro ferrite.

[0047] In the composite hybrid body based on non-oxygen-producing photosynthetic bacteria provided by the application, the exopolymers (EPS) such as polysaccharides and proteins secreted by the marsh red false single-celled bacteria can adhere the marsh red false single-celled bacteria to the surfaces of the nano-hydro ferrite and the nano-calcium carbonate to form a nano-hydro ferrite / nano-calcium carbonate / marsh red false single-celled bacteria / natural conductive high polymer hybrid body; after the nano-hydro ferrite / nano-calcium carbonate / marsh red false single-celled bacteria / natural conductive high polymer hybrid body is formed, the marsh red false single-celled bacteria can survive under light anaerobic or micro-aerobic conditions by using easily degradable organic matters in wastewater as nutrients, and can also synergize with the nano-hydro ferrite to accelerate the degradation of organic pollutants such as antibiotics through multiple pathways, and at the same time, the ability of the marsh red false single-celled bacteria to fix carbon, reduce carbon emission and generate valuable resources is enhanced. The nano-hydro ferrite particles can lead the photosynthetic electrons in the marsh red false single-celled bacteria to the outside, stimulate the marsh red false single-celled bacteria to secrete more degradation enzymes and photosensitive active substances outside the cells, and promote the multi-pathway degradation of various toxic and refractory organic pollutants such as antibiotics in wastewater. Furthermore, the more light-driven intracellular electron transfer processes with the transfer of protons are accompanied by the generation of adenosine triphosphate (ATP) and reducing equivalents (NADPH) by the marsh red false single-celled bacteria, and the carbon fixation enzyme (such as RuBisCO) can also be activated to strengthen the CO2 generated in the fixation process and convert it into valuable resource biomass, so as to realize the fixation of carbon, the reduction of carbon emission and the generation of valuable resources. Under the conditions of photoheterotrophy, the marsh red false single-celled bacteria metabolize the organic carbon sources in the wastewater to produce metabolic intermediates such as lactic acid, acetic acid and other organic acids. These acidic substances chemically react with the nano-calcium carbonate to gradually release bicarbonate. When the organic carbon sources in the wastewater are exhausted, the released bicarbonate, as an important source of inorganic carbon fixation by bacteria, synthesizes three-carbon compounds (such as glyceraldehyde phosphate, PGA) through the Calvin cycle, and further converts them into cell substances. Fe 2+ is re-oxidized to Fe 3+ as an electron donor through the process of photoautotrophy, so as to realize the circulation of Fe 2+ / Fe 3+ on the surface of the hydro ferrite.

[0048] On one hand, under light illumination, R. palustris converts light energy into electrical energy through photoelectrochemical reactions, and then transfers electrons to the surface of nanometer ferrihydrite through extracellular electron transfer. Nanometer ferrihydrite helps the bacteria to efficiently transfer electrons due to its electron acceptor and electron transfer characteristics. This process significantly up-regulates the expression of photosynthetic metabolic enzymes, extracellular electron transporters and extracellular degradation enzymes related genes of R. palustris. This enhancement promotes the photoheterotrophic metabolism of R. palustris and the extracellular secretion of photosensitive active substances, thereby promoting the biodegradation and photosensitive degradation of organic pollutants such as antibiotics; on the other hand, under light illumination, R. palustris uses light energy to drive photosynthesis to produce reducing electrons and adenosine triphosphate (ATP). Nanometer ferrihydrite, as an electron acceptor, participates in the photoelectrochemical reaction and transfers the electrons generated by the bacteria from the outside of the cell to the surface of the ferrihydrite. During the electron reduction process, nanometer ferrihydrite is accompanied by the transfer of protons. This synchronous transfer of protons and electrons is called proton-coupled electron transfer. The extracellular protons can be transferred to the bacterial cell membrane through the surface of the ferrihydrite and enter the cell through the proton channel on the membrane. That is, during the electron transfer process, ferrihydrite not only acts as an electron acceptor, but also provides a proton transfer channel inside and outside the R. palustris cell. The proton transfer forms a proton gradient across the membrane, providing additional driving force for R. palustris. This proton gradient provides additional energy for the adenosine triphosphate (ATP) synthase on the cell membrane, driving the synthesis of adenosine triphosphate (ATP). Through efficient adenosine triphosphate (ATP) synthesis and proton-coupled electron transfer, nanometer ferrihydrite helps the bacteria to enhance the expression and activity of carbon fixation enzymes (such as RuBisCO), thereby accelerating the Calvin cycle and promoting the fixation of carbon dioxide. 3+ 、Fe 2+ On the other hand, under light illumination, R. palustris has the ability to reduce nanometer ferrihydrite extracellularly in a photoheterotrophic manner. Through direct contact, a conductive band of goethite is formed. This conductive band forms a stable electron transfer channel through Fe 3+ 、Fe 2+ ions on the surface of the mineral, enhancing the efficiency of long-distance electron transfer, allowing the bacteria to transfer electrons from the cell to the mineral surface and to other electron acceptors in the water body, or directly participating in the reduction and degradation of pollutants. The released soluble Fe acts as an electron shuttle, which can transfer electrons between the bacteria and the pollutants, or directly reduce the pollutants in the water body to promote their degradation; on the other hand, nanometer calcium carbonate has a large specific surface area, and its slow-release characteristics can maintain the inorganic carbon concentration in the water body by gradually releasing bicarbonate, providing long-term stable carbon source support for the photosynthetic autotrophy of the bacteria, ensuring the supply of inorganic carbon source for the photosynthetic autotrophy of R. palustris when the organic carbon source in the wastewater is insufficient. The reduced Fe 2+ acts as an electron donor and is re-oxidized to Fe 3+The generated electrons pass through the electron transport chain to drive the synthesis of ATP to provide energy for the bacteria. And can also participate in the degradation process of organic pollutants by generating free radicals or oxidized products. This dynamic balance mechanism meets the long-term metabolic needs of the bacteria, forming an efficient and stable sewage purification and carbon reduction system. Therefore, the swamp red false single coccus in the composite hybrid body based on the non-oxygen-producing photosynthetic bacteria can not only promote the photoheterotrophic metabolism and extracellular secretion of photosensitive active substances of the swamp red false single coccus, strengthen the degradation of antibiotics and other organic pollutants, but also promote the synthesis of adenosine triphosphate (ATP) and carbon fixation enzymes (such as RuBisCO), strengthen the Calvin cycle, and form a goethite conductive band as a long-distance electron transport channel for the swamp red false single coccus, and strengthen the degradation of antibiotics and other organic pollutants. This makes the composite hybrid body based on the non-oxygen-producing photosynthetic bacteria provided by the application not only have high efficiency in degrading antibiotics and other organic pollutants, but also achieve carbon fixation and carbon emission reduction and generate valuable resources, thereby overcoming the defects that the degradation of antibiotics and other organic pollutants in the process of purifying wastewater containing organic pollutants is not good, and carbon emission is easy to cause.

[0049] As a preferred, in order to make the nanometer ferrihydrite have higher surface area, stronger surface energy, and more easily adsorb and load the swamp red false single coccus, the particle size of the nanometer ferrihydrite is controlled to be 100-500 nm, the particle size of the nanometer calcium carbonate is controlled to be 20-100 nm, and the particle size of the nanometer calcium carbonate is smaller than that of the nanometer ferrihydrite in the composite hybrid body based on the non-oxygen-producing photosynthetic bacteria provided by the application, and further preferably, the particle size of the nanometer ferrihydrite is 200-400 nm, and the particle size of the nanometer calcium carbonate is 30-50 nm.

[0050] Meanwhile, the composite hybrid body based on the non-oxygen-producing photosynthetic bacteria provided by the application also introduces conductive alginate-based polymers and other natural conductive polymer polymers, which are beneficial to electron transfer and transfer on the one hand, and improve the adhesion stability between the nanometer ferrihydrite, the nanometer calcium carbonate and the swamp red false single coccus on the other hand.

[0051] Correspondingly, the application also provides a preparation method of the composite hybrid based on non-oxygenic photosynthetic bacteria, which comprises the following steps: adding nano-ferrihydrite and nano-calcium carbonate into a suspension of Rhodopseudomonas palustris cells and stirring, so that the Rhodopseudomonas palustris cells are in full contact with the nano-ferrihydrite and the nano-calcium carbonate, and the Rhodopseudomonas palustris cells are adsorbed on the surfaces of the nano-ferrihydrite and the nano-calcium carbonate to obtain a preliminary combined nano-ferrihydrite / nano-calcium carbonate / Rhodopseudomonas palustris hybrid suspension; then, co-culturing under light, so that the exopolysaccharides (EPS) secreted by the Rhodopseudomonas palustris cells can enhance the binding force between the Rhodopseudomonas palustris cells and the nano-ferrihydrite and the nano-calcium carbonate, and the Rhodopseudomonas palustris cells are adhered to the surfaces of the nano-ferrihydrite; then, solid-liquid separation to obtain a nano-ferrihydrite / nano-calcium carbonate / Rhodopseudomonas palustris hybrid; and then, adding the hybrid into a natural polymer salt solution and fully stirring to obtain the composite hybrid based on non-oxygenic photosynthetic bacteria through ionic cross-linking.

[0052] As preferred, in order to enable the Rhodopseudomonas palustris cells to proliferate fully and perform photosynthesis to degrade organic pollutants, fix carbon and generate valuable resources, the application provides a preparation method of the composite hybrid based on non-oxygenic photosynthetic bacteria, wherein the adding amounts of the nano-ferrihydrite and the Rhodopseudomonas palustris cells are controlled, and the amount of the Rhodopseudomonas palustris cells in each liter of the Rhodopseudomonas palustris cell suspension is 9x10 8 ~3x10 9 cells, and the amount of the nano-ferrihydrite is 0.2-0.8 g; and the nano-calcium carbonate as a reserve carbon source does not directly participate in the synergistic effect of the Rhodopseudomonas palustris cells and the ferrihydrite, so as to ensure the stability and efficiency of the system, and the amount of the nano-calcium carbonate is controlled to be 0.2 g; the cell density of the Rhodopseudomonas palustris cells can improve the efficiency of degrading organic pollutants, fixing carbon and generating valuable resources, and can also avoid that too many Rhodopseudomonas palustris cells will cause fierce competition for nutrients and be not conducive to the growth of the bacteria and be prone to aging; and the concentration of the nano-ferrihydrite can improve the mutual synergistic effect with the Rhodopseudomonas palustris cells, and can also avoid that too much nano-ferrihydrite will block the light transmittance of the culture solution, so as to affect the photosynthesis of the bacteria and reduce the removal capacity of the pollutants.

[0053] As preferred, in order to enable Rhodopseudomonas palustris to secrete enough polysaccharide, protein and other extracellular polymers (EPS) so as to be better adhered to the surface of the nanometer ferrihydrite and thus carry out photosynthesis to degrade organic pollutants, fix carbon and generate valuable resources, the preparation method of the composite hybrid body based on the anoxygenic photosynthetic bacteria provided in the application further controls the light intensity of the co-culture to be 10000-60000lx, the wavelength to be 580-700nm and the time to be 12-36h; the yellow light wavelength range is between 580-590nm and the white light wavelength range is between 600-700nm; in the wavelength and light intensity range, the pigment molecules of the Rhodopseudomonas palustris can maximize the absorption of light energy and convert it into biological energy.

[0054] In view of the fact that the nanometer ferrihydrite / nanometer calcium carbonate / Rhodopseudomonas palustris / natural high molecular polymer hybrid body is a gel-like substance, in a water body environment with strong water flow, it is easy to be washed away, thus reducing the effect of degrading organic pollutants such as antibiotics and increasing the difficulty of fixing carbon and recycling valuable resources; the application further provides a composite hybrid body carbon brush based on the anoxygenic photosynthetic bacteria; the composition comprises a fiber brush, a natural conductive polymer and a nanometer ferrihydrite / nanometer calcium carbonate / Rhodopseudomonas palustris / natural conductive polymer hybrid body; the fiber brush is a conventional fiber brush structure, comprising thousands of small bristle parts and a handle part.

[0055] Correspondingly, the application further provides a preparation method of the composite hybrid body carbon brush based on the anoxygenic photosynthetic bacteria; in the preparation method, the polymer is soaked in a 100mM excess CaCl2 solution for 1 day to obtain a rehydrated hydrogel, the nanometer ferrihydrite / nanometer calcium carbonate / Rhodopseudomonas palustris / natural conductive polymer hybrid body is added to obtain a conductive polymer / hybrid body mixed suspension, which is then impregnated or sprayed onto the surface of the bristles of the fiber brush, and the nanometer ferrihydrite / nanometer calcium carbonate / Rhodopseudomonas palustris / natural conductive polymer hybrid body carbon brush can be obtained by heating and solidification.

[0056] Correspondingly, the application further provides an application of the composite hybrid body based on the anoxygenic photosynthetic bacteria or the composite hybrid body carbon brush based on the anoxygenic photosynthetic bacteria; the application is specifically as follows: the composite hybrid body based on the anoxygenic photosynthetic bacteria or the nanometer ferrihydrite / nanometer calcium carbonate / Rhodopseudomonas palustris / natural high molecular polymer hybrid body carbon brush is added to wastewater containing sulfadiazine, and synchronous carbon fixation and degradation of toxic and refractory organic pollutants are carried out under light.

[0057] The application of the composite hybrid body based on the anoxygenic photosynthetic bacteria in synchronous carbon fixation and degradation of toxic and refractory organic pollutants will be specifically described below in combination with examples and experimental examples.

[0058] Example 1

[0059] The embodiment 1 of the present application provides a preparation method of a composite hybrid based on non-oxygen-producing photosynthetic bacteria, which comprises a preparation step of nanometer ferrihydrite, a preparation step of nanometer calcium carbonate, a culture step of marshy Rhodopseudomonas, an adsorption fixation step and an adhesion fixation step.

[0060] The preparation step of nanometer ferrihydrite comprises:

[0061] Dissolve ferrous sulfate (FeSO4) ) or ferric chloride (FeCl3) ) and the like in deionized water (25°C) to prepare an iron salt solution with a concentration of 0.5 mol / L; then slowly add a 0.5 mol / L sodium hydroxide solution to the iron salt solution under stirring, control the pH value at about 7-9, and form a red-brown Fe(OH)3 precipitate. Then place the Fe(OH)3 precipitate at room temperature for 6 hours or heat it at 50-70°C for 2 hours, and keep the temperature and pH value stable, so that the Fe(OH)3 gradually transforms into a ferrihydrite precipitate, and promotes the growth and structure stabilization of the ferrihydrite crystal, obtaining a ferrihydrite with good crystal structure and high specific surface area;

[0062] Use a centrifugal device or a filtering device to separate the ferrihydrite precipitate from the supernatant, collect the obtained ferrihydrite precipitate, and repeatedly wash the ferrihydrite precipitate with deionized water for 3-5 times to remove residual sulfate ions and unreacted sodium hydroxide, and ensure the purity of the ferrihydrite;

[0063] Place the washed ferrihydrite precipitate in a vacuum drying oven and dry it at 60°C for 12 hours until the water is completely removed. The dried ferrihydrite is in the form of fine powder. Further grinding and sieving can be performed to control the particle size of the nanometer ferrihydrite at 100-300 nm to ensure its adsorption effect.

[0064] The preparation step of nanometer calcium carbonate comprises:

[0065] Dissolve sodium carbonate (Na2CO3) and calcium chloride (CaCl2) in deionized water (25°C) to prepare a carbon source solution and a calcium source solution with a concentration of 0.5 mol / L. Under mechanical stirring or magnetic stirring, slowly add the carbon source solution to the calcium source solution, keep the dropping speed uniform to prevent local supersaturation from causing particle agglomeration; control the reaction temperature at 25-40°C, which is suitable for the formation of nanoparticles; keep the pH value of the system at 8.0-10.0 to ensure the stable formation of calcium carbonate;

[0066] After the addition is completed, the reaction solution is continuously stirred for 30 minutes to 1 hour to allow the generated nano calcium carbonate particles to fully age, promote crystal growth, and increase crystallinity; the precipitate is separated using a high-speed machine or a vacuum filter; the precipitate is repeatedly washed with deionized water until the conductivity of the washing liquid approaches the initial value of the deionized water, to remove unreacted ions and impurities; the washed precipitate is dried at a low temperature of 50-80°C to prevent crystal type changes or agglomeration caused by high temperature; and the dried powder can be ground to a fine powder using a mortar or a ball mill;

[0067] By adjusting the concentrations of the calcium source and the carbonic acid source, the addition speed, the stirring speed, and the reaction temperature, the particle size of the nano calcium carbonate (generally 20-60 nm) can be effectively controlled; the use of a stabilizer (such as PVP or citric acid) can reduce the agglomeration of the nano particles during the generation and drying processes.

[0068] The culture step of the Rhodopseudomonas palustris includes:

[0069] The Rhodopseudomonas palustris is inoculated into a sterilized liquid culture medium (including PBS, algal growth medium, trace metals, complex vitamins, and carbon sources) and is cultured anaerobically at 30°C under light illumination of 10,000-60,000 lx and a wavelength of 580-700 nm for 5-7 days to obtain a seed liquid of the Rhodopseudomonas palustris; the bacterial liquid obtained by the primary culture is inoculated into a liquid culture medium at a ratio of 1:100, and is further cultured under light illumination for 48 hours to make the bacterial liquid reach the logarithmic growth phase; the Rhodopseudomonas palustris obtained at this time has a high activity and an ability to secrete extracellular polymers (EPS), and the density (OD600) of the Rhodopseudomonas palustris liquid is about 0.5-1.0. .

[0070] The adsorption and fixation step includes: adding an appropriate amount of nano ferrihydrite at a mass-volume ratio of 0.5 g:1 L of the nano ferrihydrite and the Rhodopseudomonas palustris bacterial suspension, and then adding 0.2 g of nano calcium carbonate as a reserve carbon source; the mixed suspension is stirred at a speed of 100-200 rpm for 1-2 hours using a magnetic stirrer, so that the nano ferrihydrite particles, the nano calcium carbonate, and the Rhodopseudomonas palustris in the mixed suspension are in more sufficient contact, and the Rhodopseudomonas palustris and the nano calcium carbonate are adsorbed and fixed on the surface of the nano ferrihydrite, to obtain a preliminary combined nano ferrihydrite / nano calcium carbonate / Rhodopseudomonas palustris hybrid suspension.

[0071] The adhesion fixation step includes: continuing the co-culture of the preliminarily combined nanometer ferrihydrite / nanometer calcium carbonate / swamp red pseudomonas hybrid suspension under the same light conditions, and the swamp red pseudomonas secretes extracellular polymers (EPS) such as polysaccharides and proteins during growth, which not only helps the adhesion of the bacteria, but also further enhances the interaction force between the bacteria and the nanometer ferrihydrite particles and the nanometer calcium carbonate, and the adhesion of the extracellular polymers (EPS) further strengthens the combination between the nanometer ferrihydrite, the nanometer calcium carbonate and the swamp red pseudomonas, improves the stability of the nanometer ferrihydrite / nanometer calcium carbonate / swamp red pseudomonas hybrid, and the co-culture lasts for 24 hours to make the combination more stable.

[0072] After the adhesion fixation is completed by co-culturing for 24 hours, the nanometer ferrihydrite, the nanometer calcium carbonate and the swamp red pseudomonas precipitate is separated by centrifugation at a speed of 5000 rpm for 30 min, and the precipitate is washed with deionized water for 2-3 times to remove the unabsorbed bacteria and other dissolved substances, and to ensure the purity and activity of the nanometer ferrihydrite, the nanometer calcium carbonate and the swamp red pseudomonas.

[0073] The preparation steps of the composite hybrid based on the non-oxygenic photosynthetic bacteria include:

[0074] Sodium alginate is dissolved in water to form a uniform solution, and then mixed with calcium sulfate (CaSO4) slurry to prepare a polymer with a mass / volume ratio of 2%, that is, a conductive alginate-based polymer; and the nanometer ferrihydrite / nanometer calcium carbonate / swamp red pseudomonas hybrid is quickly added to form the composite hybrid based on the non-oxygenic photosynthetic bacteria. The mass of the added CaSO4 is 15% of the mass of the sodium alginate, so as to ensure that the calcium ions and the carboxyl groups of the sodium alginate (COO-) ) have a preliminary crosslinking reaction to form a stable ion crosslinking system, which provides a basis for subsequent processing.

[0075] Example 2

[0076] The example 2 of the present application provides a preparation method of a composite hybrid based on non-oxygenic photosynthetic bacteria, and the preparation method includes the preparation steps of nanometer ferrihydrite, nanometer calcium carbonate, the culture step of swamp red pseudomonas, the adsorption fixation step and the adhesion fixation step. The difference from the example 1 is that in the adsorption fixation step, the mass / volume ratio of the nanometer ferrihydrite and the swamp red pseudomonas cell suspension is 0.2g:1L.

[0077] The preparation steps of the nanometer ferrihydrite include:

[0078] Ferrous sulfate (FeSO4) ) or ferric chloride (FeCl3) ) Iron salt is dissolved in deionized water (25°C) to prepare an iron salt solution with a concentration of 0.5 mol / L; 0.5 mol / L sodium hydroxide solution is slowly added to the iron salt solution under stirring, and the pH value is controlled at about 7-9 to form a red-brown Fe(OH)3 precipitate; then the Fe(OH)3 precipitate is placed at room temperature for 6 hours or heated at 50-70°C for 2 hours, and the temperature and pH value are kept stable, so that the Fe(OH)3 gradually transforms into ferrihydrite precipitate, and the growth of ferrihydrite crystal and the structure stabilization are promoted, thereby obtaining ferrihydrite with good crystal structure and high specific surface area;

[0079] The ferrihydrite precipitate is separated from the supernatant by using a centrifugal device or a filtering device, and the obtained ferrihydrite precipitate is collected and washed repeatedly with deionized water for 3-5 times to remove residual sulfate ions and unreacted sodium hydroxide, so as to ensure the purity of the ferrihydrite;

[0080] The washed ferrihydrite precipitate is placed in a vacuum drying oven and dried at 60°C for 12 hours until the water is completely removed, and the dried ferrihydrite is in the form of fine powder. The particle size of the nanometer ferrihydrite can be controlled at 100-300 nm by further grinding and screening, so as to ensure its adsorption effect.

[0081] The preparation steps of the nanometer calcium carbonate include:

[0082] Sodium carbonate (Na2CO3) and calcium chloride (CaCl2) are dissolved in deionized water (25°C) to prepare a carbon source solution and a calcium source solution with a concentration of 0.5 mol / L. Under the condition of mechanical stirring or magnetic stirring, the carbon source solution is slowly added to the calcium source solution, the dropping speed is kept uniform to prevent local supersaturation from causing particle agglomeration; the reaction temperature is controlled at 25-40°C, which is suitable for the formation of nanometer particles; and the pH value of the system is kept at 8.0-10.0 to ensure that the calcium carbonate is generated in a stable form;

[0083] After the dropping is completed, the reaction solution is continuously stirred for 30 minutes to 1 hour to allow the generated nanometer calcium carbonate particles to fully mature, promote the crystal growth and improve the crystallinity; the precipitate is separated by using a high-speed machine or a vacuum filter; the precipitate is repeatedly washed with deionized water until the conductivity of the washing liquid approaches the initial value of the deionized water, so as to remove unreacted ions and impurities; and the washed precipitate is dried at a low temperature of 50-80°C to prevent the crystal form from changing or agglomerating due to high temperature; and the dried powder can be ground to be fine by using a mortar or a ball mill;

[0084] By adjusting the concentration of the calcium source and the carbon source, the dropping speed, the stirring speed and the reaction temperature, the particle size (generally 20-60 nm) of the nanometer calcium carbonate can be effectively controlled; and the use of a stabilizer (such as PVP or citric acid) can reduce the agglomeration of the nanometer particles during the generation and drying process.

[0085] The culturing step of the Rhodopseudomonas palustris includes:

[0086] The Rhodopseudomonas palustris is inoculated into a sterilized liquid culture medium (including PBS, algal growth medium, trace metals, complex vitamins, and carbon sources) and cultured anaerobically at 30°C under 10000-60000 lx light with a wavelength of 580-700 nm for 5-7 days to obtain a seed solution of the Rhodopseudomonas palustris; the bacterial solution obtained by the primary culture is inoculated into a liquid culture medium at a ratio of 1:100, and the bacterial solution is further cultured under light for 48 hours to make the bacterial solution reach the logarithmic growth phase, so that the Rhodopseudomonas palustris obtained at this time has high activity and the ability to secrete extracellular polymers (EPS); and the density (OD600) of the Rhodopseudomonas palustris solution is about 0.5-1.0. .

[0087] The adsorption and fixation step includes: adding a proper amount of nanometer ferrihydrite according to the mass-volume ratio of 0.2 g:1 L of the nanometer ferrihydrite and the Rhodopseudomonas palustris bacterial suspension, and then adding 0.2 g of nanometer calcium carbonate as a reserve carbon source; and using a magnetic stirrer to stir and mix the suspension at a speed of 100-200 rpm for 1-2 hours, so that the contact among the nanometer ferrihydrite particles, the nanometer calcium carbonate, and the Rhodopseudomonas palustris in the mixed suspension is more sufficient, and the Rhodopseudomonas palustris and the nanometer calcium carbonate are adsorbed and fixed on the surface of the nanometer ferrihydrite to obtain a preliminary combined nanometer ferrihydrite / nanometer calcium carbonate / Rhodopseudomonas palustris hybrid suspension.

[0088] The adhesion and fixation step includes: continuing to co-culture the preliminary combined nanometer ferrihydrite / nanometer calcium carbonate / Rhodopseudomonas palustris hybrid suspension under the same light conditions; the Rhodopseudomonas palustris secretes extracellular polymers (EPS) such as polysaccharides and proteins during the growth process, which not only helps the adhesion of the bacteria, but also further enhances the interaction force among the bacteria, the nanometer ferrihydrite particles, and the nanometer calcium carbonate; the adhesion of the extracellular polymers (EPS) further strengthens the combination among the nanometer ferrihydrite, the nanometer calcium carbonate, and the Rhodopseudomonas palustris, improves the stability of the nanometer ferrihydrite / nanometer calcium carbonate / Rhodopseudomonas palustris hybrid, and makes the combination more stable by co-culturing for 24 hours.

[0089] After the adhesion and fixation are completed by co-culturing for 24 hours, the nanometer ferrihydrite, the nanometer calcium carbonate, and the Rhodopseudomonas palustris are separated by centrifugation at a speed of 5000 rpm for 30 min, the precipitate is washed with deionized water for 2-3 times to remove the unadsorbed bacteria and other dissolved substances, and the purity and activity of the nanometer ferrihydrite, the nanometer calcium carbonate, and the Rhodopseudomonas palustris are ensured.

[0090] The preparation step of the composite hybrid based on the non-oxygenic photosynthetic bacteria includes:

[0091] Sodium alginate is dissolved in water to form a uniform solution, which is then mixed with calcium sulfate (CaSO4) slurry to form a polymer with a mass volume ratio of 2%, which is a conductive alginate-based polymer; nano-ferrihydrite / nano-calcium carbonate / Pseudomonas palustris hybrid is quickly added to form a composite hybrid based on non-oxygen photosynthetic bacteria. The mass of added CaSO4 is 15% of the mass of sodium alginate to ensure that the calcium ions and the carboxyl groups of sodium alginate ( ) undergoes a preliminary cross-linking reaction to form a structurally stable ionic cross-linking system, providing a basis for subsequent processing.

[0092] Example 3

[0093] Example 3 of the present application provides a preparation method for a composite hybrid based on non-oxygen-producing photosynthetic bacteria, the preparation method including a preparation step of nano-ferrihydrite, a preparation step of nano-calcium carbonate, a cultivation step of Rhodopseudomonas palustris, an adsorption and fixation step, and an adhesion and fixation step. The difference from Example 1 is that in the adsorption and fixation step, the mass-to-volume ratio of nano-ferrihydrite and Rhodopseudomonas palustris cell suspension is 1g:1L.

[0094] The preparation steps of nano ferrihydrite include:

[0095] Use ferrous sulfate ( ) or ferric chloride ( ) and other iron salts are dissolved in deionized water (25°C) to prepare an iron salt solution with a concentration of 0.5 mol / L; then, 0.5 mol / L sodium hydroxide solution is slowly added dropwise to the iron salt solution with stirring, and the pH value is controlled at about 7-9 to form a reddish-brown Fe(OH)3 precipitate. The Fe(OH)3 precipitate is then left to stand at room temperature for 6 hours or heated at 50-70°C for 2 hours, while maintaining a stable temperature and pH value, so that the Fe(OH)3 is gradually converted into ferrihydrite precipitate, and the growth and structural stabilization of ferrihydrite crystals are promoted, thereby obtaining ferrihydrite with a good crystal structure and a high specific surface area;

[0096] Use a centrifugal device or a filtration device to separate the ferrihydrite precipitate from the supernatant, collect the obtained ferrihydrite precipitate, and repeatedly wash the ferrihydrite precipitate with deionized water 3-5 times to remove residual sulfate ions and unreacted sodium hydroxide to ensure the purity of the ferrihydrite;

[0097] The washed ferrihydrite precipitate is placed in a vacuum drying oven and dried at 60°C for 12 hours until the water is completely removed. The dried ferrihydrite is a fine powder. Further grinding and screening can be performed to control the particle size of the nano-ferrihydrite to 100-300nm to ensure its adsorption effect.

[0098] The preparation steps of nano calcium carbonate include:

[0099] A carbonate source solution and a calcium source solution are prepared by dissolving sodium carbonate (Na2CO3) and calcium chloride (CaCl2) in deionized water (25°C) to a concentration of 0.5 mol / L. The carbonate source solution is slowly added to the calcium source solution under mechanical or magnetic stirring, keeping the addition rate uniform to prevent local supersaturation and particle agglomeration; the reaction temperature is controlled at 25-40°C, suitable for nanoparticle formation; the pH of the system is maintained at 8.0-10.0 to ensure stable formation of calcium carbonate;

[0100] After the addition is complete, the reaction solution is stirred for 30 minutes to 1 hour to allow the generated calcium carbonate nanoparticles to fully age, promoting crystal growth and increasing crystallinity; the precipitate is separated using a high-speed machine or vacuum filter; the precipitate is washed repeatedly with deionized water until the conductivity of the wash water approaches the initial value of the deionized water, removing unreacted ions and impurities; the washed precipitate is dried at a low temperature of 50-80°C to prevent crystal type changes or agglomeration caused by high temperatures; the dried powder can be ground to a fine powder using a mortar or ball mill;

[0101] By adjusting the concentrations of the calcium source and the carbonate source, the addition rate, the stirring speed, and the reaction temperature, the particle size of the calcium carbonate nanoparticles (typically 20-60 nm) can be effectively controlled; the use of stabilizers such as PVP or citric acid can reduce nanoparticle agglomeration during formation and drying.

[0102] The culture steps of Rhodopseudomonas palustris include:

[0103] Rhodopseudomonas palustris is inoculated into a sterilized liquid culture medium (including PBS, algal growth medium, trace metals, complex vitamins, and carbon sources) and cultured anaerobically at 30°C, pH 6.5-7.5, 10,000-60,000 lx illumination, and a wavelength of 580-700 nm for 5-7 days to obtain a seed solution of Rhodopseudomonas palustris; the primary culture solution is then inoculated into a liquid culture medium at a ratio of 1:100 and cultured under suitable temperature, pH, and illumination conditions for 48 hours to reach the logarithmic growth phase, resulting in Rhodopseudomonas palustris with high activity and the ability to secrete extracellular polymeric substances (EPS); the density of the Rhodopseudomonas palustris solution (OD600) is about .

[0104] The adsorption fixation step includes: adding an appropriate amount of nanometer ferrihydrite according to the mass-volume ratio of 1 g: 1 L of nanometer ferrihydrite and Rhodopseudomonas palustris cell suspension, then adding 0.2 g of nanometer calcium carbonate as a reserve carbon source, and using a magnetic stirrer to stir the mixed suspension at a speed of 100-200 rpm for 1-2 hours, so that the contact between the nanometer ferrihydrite particles, nanometer calcium carbonate and Rhodopseudomonas palustris in the mixed suspension is more sufficient, and Rhodopseudomonas palustris and nanometer calcium carbonate are adsorbed and fixed on the surface of nanometer ferrihydrite, obtaining a preliminary combined nanometer ferrihydrite / nanometer calcium carbonate / Rhodopseudomonas palustris hybrid suspension.

[0105] The adhesion fixation step includes: continuing to co-culture the preliminary combined nanometer ferrihydrite / nanometer calcium carbonate / Rhodopseudomonas palustris hybrid suspension under the same light conditions, and Rhodopseudomonas palustris will secrete extracellular polymers (EPS) such as polysaccharides and proteins during growth, which not only help the adhesion of bacteria, but also further enhance the interaction force between bacteria and ferrihydrite particles and nanometer calcium carbonate. The adhesion of extracellular polymers (EPS) will further strengthen the combination between nanometer ferrihydrite, nanometer calcium carbonate and Rhodopseudomonas palustris, improve the stability of the nanometer ferrihydrite / nanometer calcium carbonate / Rhodopseudomonas palustris hybrid, and co-culture for 24 hours to make the combination more stable.

[0106] After 24 hours of co-culture for adhesion fixation, centrifugation is performed at a speed of 5000 rpm for 30 min, and the nanometer ferrihydrite, nanometer calcium carbonate and Rhodopseudomonas palustris precipitate is separated, washed with deionized water for 2-3 times, and the non-adsorbed bacteria and other dissolved substances are removed to ensure the purity and activity of nanometer ferrihydrite, nanometer calcium carbonate and Rhodopseudomonas palustris.

[0107] The preparation steps of the composite hybrid based on non-oxygen-producing photosynthetic bacteria include:

[0108] Sodium alginate is dissolved in water to form a uniform solution, then mixed with calcium sulfate (CaSO4) slurry to prepare a polymer with a mass-volume ratio of 2%, that is, a conductive alginate-based polymer; quickly add the nanometer ferrihydrite / nanometer calcium carbonate / Rhodopseudomonas palustris hybrid to form a composite hybrid based on non-oxygen-producing photosynthetic bacteria. The mass of CaSO4 added is 15% of the mass of sodium alginate to ensure that the calcium ions and the carboxyl groups of sodium alginate (—COO ) ) occur a preliminary crosslinking reaction to form a stable ion crosslinking system, providing a basis for subsequent processing.

[0109] Example 4

[0110] The embodiment 4 of the present application provides a preparation method of the composite hybrid carbon brush based on anoxygenic photosynthetic bacteria, which comprises the steps of preparing a conductive polymer / hybrid mixed suspension and loading the suspension on the fiber brush.

[0111] The step of preparing the conductive polymer / hybrid mixed suspension comprises the following steps: dissolving sodium alginate in water and mixing with calcium sulfate (CaSO4) slurry to prepare a polymer with a mass-volume ratio of 2%. The mass of the added CaSO4 is 15% of the mass of the sodium alginate. The polymer is immediately molded and gelled between glass plates using a 3 mm thick spacer, and then stored in a 5°C cooler for 1 day to complete the ionic crosslinking. The prepared pre-gel is anisotropically dried / shrunk in a flat-bottomed dish at 20-25°C and 20-25% relative humidity (RH) for 3 days. The obtained dry sheet is soaked in a 100 mM excess CaCl2 solution for 1 day, and the material's conductivity and mechanical properties are improved by deep crosslinking of multivalent metal ions. After rinsing with distilled water, a rehydrated hydrogel is obtained. Then, the rehydrated hydrogel is mixed with the composite hybrid based on anoxygenic photosynthetic bacteria prepared according to any one of embodiments 1-3 at a ratio of 30% (w / v), and stirred uniformly to form a conductive polymer / hybrid mixed suspension.

[0112] The step of loading the suspension on the fiber brush comprises the following steps: immersing the bristles of the treated fiber brush in the conductive polymer / hybrid mixed suspension and continuously stirring at a speed of 100-150 rpm for 2-4 hours to allow the bristles to be fully impregnated, or spraying the conductive polymer / hybrid mixed suspension onto the bristles of the fiber brush, and then placing it at room temperature or heating and curing to obtain a composite hybrid carbon brush based on anoxygenic photosynthetic bacteria.

[0113] According to the flow rate and pollutant concentration of the water body, the prepared composite hybrid carbon brush based on anoxygenic photosynthetic bacteria is uniformly distributed and installed on the fixed frame in the biological treatment tank or suspended above the water body to degrade organic pollutants, fix carbon, and generate valuable resources. At the same time, due to the loading of the nanometer ferrihydrite / swamp red pseudomonas hybrid on the fiber brush, the valuable resources are very easy to recover.

[0114] Experimental Example 1

[0115] In this experimental example 1, the microstructure of the nanometer ferrihydrite, swamp red pseudomonas, and composite hybrid based on anoxygenic photosynthetic bacteria provided in embodiment 1 is characterized.

[0116] Among them, the scanning electron microscope image of the nanometer ferrihydrite is shown in Figure 1 Figure a, and the scanning electron microscope image of the swamp red pseudomonas is shown in Figure 1As shown in FIG. 2B, it can be seen that the nanoscale ferrihydrite is gathered together to present irregular clumps, and the surface is loose and porous, which is conducive to the adsorption and loading of R. palustris, while the surface of R. palustris is smooth.

[0117] The morphologies of R. palustris and nanoscale calcium carbonate fixed to the nanoscale ferrihydrite are as shown in FIG. 2C. Figure 1 As shown in FIG. 2C, it can be seen that R. palustris and nanoscale calcium carbonate are closely attached to the surface of the nanoscale ferrihydrite, which indicates that the nanoscale ferrihydrite can provide abundant attachment sites for R. palustris and nanoscale calcium carbonate, and the nanoscale calcium carbonate serves as a supplemental carbon source, while the direct contact of R. palustris with the nanoscale ferrihydrite is conducive to the degradation of organic pollutants, carbon fixation and the generation of valuable resources. Figure 1 As shown in FIG. 2C, it can be seen that R. palustris and nanoscale calcium carbonate are closely attached to the surface of the nanoscale ferrihydrite, which indicates that the nanoscale ferrihydrite can provide abundant attachment sites for R. palustris and nanoscale calcium carbonate, and the nanoscale calcium carbonate serves as a supplemental carbon source, while the direct contact of R. palustris with the nanoscale ferrihydrite is conducive to the degradation of organic pollutants, carbon fixation and the generation of valuable resources.

[0118] Experimental Example 2

[0119] In this experimental example 2, the nanoscale ferrihydrite, R. palustris and the composite hybrid based on non-oxygenic photosynthetic bacteria provided in Examples 1-3 are subjected to performance testing for degrading the organic pollutant sulfadiazine (SDZ).

[0120] The performance testing includes the following steps:

[0121] The step of configuring the simulated wastewater includes adding PBS, algal medium, trace metals, vitamins, anhydrous sodium acetate, sulfadiazine and other components into deionized water to configure the simulated wastewater, and the concentration of sulfadiazine (SDZ) in the simulated wastewater is controlled to be 1 mg / L.

[0122] The step of testing the removal rate and kinetics of sulfadiazine (SDZ) in the simulated wastewater includes respectively adding the nanoscale ferrihydrite (0.5 g: 1 L) provided in Example 1, R. palustris (0.5 g: 1 L) and the composite hybrid based on non-oxygenic photosynthetic bacteria (0.5 g: 1 L) into the simulated wastewater, and the removal rate and kinetics of sulfadiazine (SDZ) in the simulated wastewater are tested. ) and composite hybrid based on non-oxygenic photosynthetic bacteria (mass-volume ratio of 0.5 g:1 L of nanoscale green rust and Rhodopseudomonas palustris cell suspension) were added to the simulated wastewater at the same concentration, and then the degradation of sulfadiazine (SDZ) was observed under light or dark conditions for 96 h. During the test, three parallel groups were set to reduce experimental error. The concentration of sulfadiazine (SDZ) was tested every 12 hours, and the concentration of sulfadiazine (SDZ) was determined by high performance liquid chromatography (HPLC, Essentia LC-16; Shimadzu Corporation, Japan) at a wavelength of 265 nm, and the mobile phase consisted of 90:10 (v:v) 0.1% formic acid and acetonitrile. The removal rate of sulfadiazine (SDZ) was calculated by the formula C0-C t / C0, where C0-C t was the concentration of sulfadiazine (SDZ) at intervals of 12 hours, and the results are shown in Figure 2 . The results of different degradation removal pathways of sulfadiazine (SDZ) in simulated wastewater by nanoscale green rust-R. palustris hybrid are shown in Figure 3 .

[0123] The steps for testing the amount of CO2 generated during the degradation of sulfadiazine (SDZ) in simulated wastewater, and the concentration of CO2 in the headspace was determined by gas chromatography (FULI GC9790II, China). The test lasted for 8 days. The gas chromatography used the following parameters: separation column TDX-01 ( ); carrier gas argon, 45 mL / min; column temperature, 120°C; detector temperature: 160°C; injection temperature 160°C, and the results are shown in Figure 4 .

[0124] As can be seen from Figure 2 , the effect of R. palustris on the degradation and removal of sulfadiazine (SDZ) under light is poor, and after 96 hours, the degradation and removal rate of sulfadiazine (SDZ) is only 43.3%. The degradation and removal rate of sulfadiazine (SDZ) by the composite hybrid based on non-oxygenic photosynthetic bacteria provided in Example 1 can reach 83.3%. Under the same addition concentration, the degradation and removal rate of sulfadiazine (SDZ) by the nanoscale green rust / R. palustris hybrid is greater than the sum of the degradation and removal rates of sulfadiazine (SDZ) by R. palustris and nanoscale green rust. The first-order kinetic curve of sulfadiazine (SDZ) shows that, under light, the degradation rate constant k of SDZ by the composite hybrid based on non-oxygenic photosynthetic bacteria can reach , which is 3.24 times higher than the degradation rate constant k of SDZ by R. palustris, which is only . Under dark conditions, the removal rate of SDZ by the composite hybrid based on non-oxygenic photosynthetic bacteria is only 7.9%, and the degradation rate constant k is It is shown that the complex hybrid based on anoxygenic photosynthetic bacteria has little effect on hydrolysis in the process of treating wastewater, and nanometer ferrihydrite is almost unable to degrade and remove sulfadiazine (SDZ) under light.

[0125] From Figure 3 It can be seen that the complex hybrid based on anoxygenic photosynthetic bacteria can degrade and metabolize sulfadiazine (SDZ) through multiple pathways, and the complex hybrid based on anoxygenic photosynthetic bacteria can remove sulfadiazine (SDZ) through direct enzymatic biodegradation, EPS-mediated indirect photodegradation, and adsorption. In the first 24 hours, biodegradation is the main removal mechanism, contributing 25%, which may be because the dissolved nanometer ferrihydrite enters the inside of the Rhodopseudomonas palustris cell, where different reductions occur to produce energy, enhancing cell metabolism, in addition, it also acts as an iron source for the synthesis of cell components, thereby promoting the growth of Rhodopseudomonas palustris; After 24 hours, the ability of indirect photodegradation increases, contributing 29%, which may be because nanometer ferrihydrite as a terminal electron acceptor enhances the extracellular electron transfer ability of Rhodopseudomonas palustris, while stimulating it to secrete more extracellular polymeric substance (EPS), which produces photosensitive active substances under continuous light to participate in the degradation of sulfadiazine (SDZ). Compared with physical and chemical adsorption that reaches adsorption equilibrium in a short time, the adsorption of sulfadiazine (SDZ) by the complex hybrid based on anoxygenic photosynthetic bacteria increases with time, which may be due to the extracellular reduction of ferrihydrite stimulating the secretion of extracellular polymeric substance (EPS) by purple non-sulfur photosynthetic bacteria, or the transformation of ferrihydrite crystal phase forming a conductive path, resulting in enhanced adsorption.

[0126] From Figure 4 It can be seen that the complex hybrid based on anoxygenic photosynthetic bacteria provided in Examples 1-3, nanometer ferrihydrite provided in Example 1, and Rhodopseudomonas palustris have carbon fixation effects under light or dark conditions; from Figure 4It can be seen that with the extension of time, there is almost no carbon dioxide produced in the nanometer ferrihydrite system under light, while the total amount of carbon dioxide released by the complex hybrid based on non-oxygenic photosynthetic bacteria increases, reaching the highest value on the eighth day. This is because in the process of metabolizing organic matter, Rhodopseudomonas palustris can decompose complex organic compounds through a series of biochemical reactions to generate the final product carbon dioxide, while providing energy for the cell to maintain growth and physiological functions. Although Rhodopseudomonas palustris can decompose organic matter to produce carbon dioxide, it also has the ability of photosynthesis, which can use light energy to fix carbon dioxide in the environment into organic matter through the Calvin cycle. Therefore, the bacteria achieve a dynamic balance between carbon fixation and carbon release: decomposing organic matter to release carbon dioxide, while under photosynthetic conditions, part of the carbon dioxide is re-fixed into organic matter through the Calvin cycle. Further comparison can show that with the extension of time, the rate of carbon dioxide released by Rhodopseudomonas palustris under light is the fastest, and the total amount of carbon dioxide released is also the most, while the rate and total amount of carbon dioxide released by the complex hybrid based on non-oxygenic photosynthetic bacteria provided in Example 2 (0.2 g / L nanometer ferrihydrite), the complex hybrid based on non-oxygenic photosynthetic bacteria provided in Example 3 (1 g / L nanometer ferrihydrite), and the nanometer ferrihydrite / Rhodopseudomonas palustris hybrid under dark conditions (1 g / L nanometer ferrihydrite) gradually decrease, while under dark conditions, the activity of Rhodopseudomonas palustris decreases significantly, and the growth rate of carbon dioxide content slows down, indicating that light is crucial to the growth process of the bacteria. The nanometer ferrihydrite without the addition of Rhodopseudomonas palustris has almost no significant improvement in carbon dioxide content, and the carbon dioxide content remains basically at the initial level, indicating that nanometer ferrihydrite itself does not have the ability to fix carbon and needs to work synergistically with bacteria. The rate and total amount of carbon dioxide released by the complex hybrid based on non-oxygenic photosynthetic bacteria provided in Example 1 (0.5 g / L nanometer ferrihydrite) under light are close to the rate and total amount of carbon dioxide released by the complex hybrid based on non-oxygenic photosynthetic bacteria provided in Example 3 (1 g / L nanometer ferrihydrite) under light, which indicates that when the concentration of nanometer ferrihydrite increases to 0.5 g / L nanometer ferrihydrite, it has reached a good synergistic effect with Rhodopseudomonas palustris, and has a good effect of degrading organic pollutants, fixing carbon, and generating valuable resources.

[0127] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A composite hybrid based on non-oxygenous photosynthetic bacteria, characterized in that include: Nanoferrihydrite, nanocalcium carbonate, and Rhodopseudomonas palustris; The nano calcium carbonate and Rhodopseudomonas palustris adhere to the surface of the nano ferrihydrite.

2. A composite hybrid based on non-oxygenous photosynthetic bacteria according to claim 1, characterized in that: The composite hybrid based on non-oxygenous photosynthetic bacteria further comprises: a natural conductive high molecular polymer; The nano calcium carbonate and Rhodopseudomonas palustris adhere to the surface of the nano ferrihydrite through a natural conductive high molecular polymer.

3. A composite hybrid based on non-oxygenous photosynthetic bacteria according to claim 2, characterized in that: The natural conductive high molecular polymer is a conductive alginate-based polymer.

4. A composite hybrid based on non-oxygenous photosynthetic bacteria according to claim 1, characterized in that: The particle size of the nano-ferrihydrite is 100-500 nm, the particle size of the nano-calcium carbonate is 20-100 nm, and the particle size of the nano-calcium carbonate is smaller than that of the nano-ferrihydrite.

5. The method for preparing a composite hybrid based on non-oxygenous photosynthetic bacteria according to any one of claims 1 to 4, characterized in that: Including steps: Step A1, adding nano-ferrihydrite and nano-calcium carbonate to a suspension of Rhodopseudomonas palustris cells and stirring to obtain a preliminarily combined nano-ferrihydrite / nano-calcium carbonate / Rhodopseudomonas palustris hybrid suspension; Step A2: co-culturing the preliminarily combined nano-ferrihydrite / nano-calcium carbonate / Rhodopseudomonas palustris hybrid suspension under light, and performing solid-liquid separation to obtain the nano-ferrihydrite / nano-calcium carbonate / Rhodopseudomonas palustris hybrid; Step A3: adding the nano-ferrihydrite / nano-calcium carbonate / Rhodopseudomonas palustris hybrid into a natural polymer salt solution, stirring the mixture thoroughly, and then performing ionic cross-linking to obtain a composite hybrid based on non-oxygen-producing photosynthetic bacteria.

6. The method for preparing a composite hybrid based on non-oxygenous photosynthetic bacteria according to claim 5, characterized in that: In step A1, the concentration of the Rhodopseudomonas palustris suspension is The mass volume ratio of the nano-ferrihydrite, nano-calcium carbonate and Rhodopseudomonas palustris suspension is 0.2~1g:0.2g:1L; In step A2, the co-culture light intensity is 10,000-60,000 lx, the wavelength is 580-700 nm, and the time is 12-36 h; In step A3, the mass volume ratio of the natural polymer salt solution is 1-3%.

7. A composite hybrid carbon brush based on non-oxygen-producing photosynthetic bacteria, characterized in that: include: A fiber brush, a conductive high molecular polymer and a composite hybrid based on non-oxygen-producing photosynthetic bacteria according to any one of claims 1 to 4; The composite hybrid based on non-oxygen-producing photosynthetic bacteria according to any one of claims 1 to 4 is adhered and fixed to the bristle surface of the fiber brush through a conductive polymer hydrogel.

8. The method for preparing a composite hybrid carbon brush based on non-oxygen-producing photosynthetic bacteria according to claim 7, characterized in that: Including steps: Step B1, soaking the conductive alginate-based polymer in a 100 mM excess CaCl2 solution for 1 day to obtain a rehydrated hydrogel; Step B2, adding the composite hybrid based on non-oxygenous photosynthetic bacteria according to any one of claims 1 to 4 to the rehydrated hydrogel to obtain a conductive polymer / hybrid mixed suspension; Step B3: impregnate or spray the polymer / hybrid mixed suspension onto the bristle surface of the fiber brush, and solidify to obtain a composite hybrid carbon brush based on non-oxygen-producing photosynthetic bacteria.

9. Use of a composite hybrid based on non-oxygen-producing photosynthetic bacteria according to any one of claims 1 to 4 or a composite hybrid carbon brush based on non-oxygen-producing photosynthetic bacteria according to claim 7 in simultaneous carbon fixation and degradation of toxic and refractory organic pollutants.

10. The use according to claim 9, characterized in that The application specifically includes: adding a composite hybrid based on non-oxygen-producing photosynthetic bacteria as described in any one of claims 1-2 or a composite hybrid carbon brush based on non-oxygen-producing photosynthetic bacteria as described in claim 7 to wastewater containing sulfadiazine, and simultaneously fixing carbon and degrading toxic and difficult-to-degrade organic pollutants under light.

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