Method for synchronously converting hydrogen sulfide and sulfate radicals into elemental sulfur and sulfur-containing amino acid

Abstract

The invention provides a method for synchronously converting hydrogen sulfide and sulfate radicals into elemental sulfur and sulfur-containing amino acid. The method comprises the following steps: in an aerobic state, pH value is lt; the method comprises the following steps: under the conditions that the concentration of sulfur ions is greater than or equal to 1.5 and the concentration of SO4 < 2-> is greater than or equal to 2g / L, enriching microbial florae containing mycobacteria, so that the oxidation reaction of hydrogen sulfide and the reduction reaction of sulfate radicals are synchronously carried out to obtain elemental sulfur and sulfur-containing amino acid. According to the method, two metabolic pathways of sulfur oxidation and sulfate reduction are ingeniously combined, efficient utilization and resource recycling of sulfur elements in hydrogen sulfide gas and sulfate wastewater are achieved through microbial flora containing mycobacteria, and an innovative, efficient and environment-friendly solution is provided for high-value recycling of sulfur-containing waste; and a new way is opened up for the application of the biotechnology in the treatment of extreme industrial wastes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sulfur-containing waste utilization, and particularly relates to a method for synchronously converting hydrogen sulfide and sulfate into elemental sulfur and sulfur-containing amino acids. BACKGROUND

[0002] Hydrogen sulfide (H2S) and high-concentration sulfate wastewater are typical sulfur-containing pollutants generated in the processes of industrial, agricultural and municipal waste treatment, and are widely sourced and significantly harmful. H2S is commonly found in natural gas exploitation, petroleum and chemical industry, coal chemical industry, livestock and poultry breeding, landfill, sewage pipe network and anaerobic fermentation of organic matter, and has the characteristics of high toxicity, foul odor and strong corrosivity, which can easily cause poisoning of personnel, corrosion of equipment and public complaints. Its combustion product, sulfur dioxide (SO2), is an important precursor of acid rain and PM2.5 secondary generation, which seriously threatens the ecological environment and human health. At the same time, sulfate wastewater is widely present in mining, metallurgy, tanning, papermaking, food processing and seawater desalination industries, and high-concentration SO4 2- not only causes the increase of water mineralization and hardness, affecting industrial reuse and agricultural irrigation, but also can be reduced to H2S under anaerobic conditions, leading to secondary pollution, damaging aquatic ecosystems, and even causing biological corrosion of pipelines and concrete structures.

[0003] Traditional physical and chemical methods (such as Claus desulfurization, alkali absorption, iron salt precipitation, ozone oxidation, etc.) can achieve H2S removal, but generally have high energy consumption, large reagent consumption, high operation cost, prominent secondary pollution risk, and are difficult to synchronously treat sulfate wastewater; while single biological methods (such as sulfur-oxidizing bacteria desulfurization, sulfate-reducing bacteria SRB treatment) are limited by single function, poor environmental adaptability, and low added value of products (such as only generating elemental sulfur or sulfide precipitate), and are difficult to realize high-value utilization of sulfur elements.

[0004] With the promotion of the "double carbon" strategy and circular economy, it has become an industry consensus to convert waste sulfides into high-value products. Elemental sulfur (S 0 ) as a key raw material for the fertilizer, rubber, pharmaceutical, pesticide and other industries has stable market demand; and sulfur-containing amino acids such as methionine and cysteine as feed additives, pharmaceutical intermediates and core ingredients of health products have significant economic value (methionine market price is about 30-50 thousand yuan / ton). However, the existing technology has not broken through the bottleneck of "synchronous treatment of H2S and sulfate", and cannot realize the closed-loop utilization of sulfur elements from waste gas / wastewater to high-value products.

[0005] Therefore, it is urgent to develop a method that can realize the collaborative and efficient conversion of H2S and sulfate, and synchronously recover elemental sulfur and sulfur-containing amino acids, so as to break through the limitations of traditional technology and provide a green, efficient and economic integrated solution for sulfur-containing waste treatment and resourceization. SUMMARY

[0006] The present application provides a method for synchronously converting hydrogen sulfide and sulfate into elemental sulfur and sulfur-containing amino acids, which solves the problem that the prior art cannot realize the efficient conversion of hydrogen sulfide and sulfate, and the present application ingeniously combines sulfur oxidation and sulfate reduction metabolic pathways, and uses mycobacterium-containing microbial flora to realize the efficient utilization and recycling of sulfur elements in hydrogen sulfide gas and sulfate wastewater.

[0007] According to the first aspect of the present application, the present application also provides a method for synchronously converting hydrogen sulfide and sulfate into elemental sulfur and sulfur-containing amino acids, comprising: under the conditions of aerobic, pH < 1.5 and SO4 2- Concentration ≥ 2 g / L, the oxidation reaction of hydrogen sulfide and the reduction reaction of sulfate are simultaneously carried out by enriching mycobacterium-containing microbial flora, and elemental sulfur and sulfur-containing amino acids are obtained.

[0008] The method of the present application can quickly enrich mycobacterium-containing microbial flora by creating an aerobic, high-acidity and high-sulfate extreme environment, and the microbial flora can oxidize sulfide to solid elemental sulfur, while providing electrons to drive assimilative sulfate reduction, thereby converting sulfate in the system to sulfur-containing amino acids. The method of the present application ingeniously combines sulfur oxidation and sulfate reduction metabolic pathways, and realizes the efficient utilization and recycling of sulfur elements in hydrogen sulfide gas and sulfate wastewater. The method has the advantages of simple operation, environmental friendliness and wide application, and is especially suitable for industrial sulfur-containing waste treatment and resource recycling.

[0009] Preferably, the pH value is greater than or equal to 0.7 and less than 1.5, and the sulfate concentration is greater than or equal to 2 g / L and less than or equal to 25 g / L.

[0010] According to the present application, a method for synchronously converting hydrogen sulfide and sulfate into elemental sulfur and sulfur-containing amino acids is provided, comprising the following steps: Step S1: Under aerobic conditions, hydrogen sulfide gas is introduced into sulfate wastewater-containing culture solution, and the culture solution is continuously circulated and trickled in the filler with microbial membrane attached, until the hydrogen sulfide gas removal rate reaches more than 90% and the pH value of the culture solution begins to decrease; Step S2: The pH value of the culture solution is controlled to decrease slowly to less than 1.5, and under the conditions of pH < 1.5 and sulfate concentration ≥ 2 g / L, the microbial flora is cultured in a targeted manner until the abundance of mycobacterium reaches more than 60%; Step S3: Under the condition of pH < 1.5, sulfate wastewater is added and periodically replaced, and the O2 / H2S gas supply ratio is controlled, so that the oxidation reaction of hydrogen sulfide and the reduction reaction of sulfate are simultaneously carried out.

[0011] In the above scheme, step S1, biological system startup, aims to establish the initial operating conditions and preliminary adaptability of the system. Aeration provides oxygen, introduces hydrogen sulfide and sulfate, and circulates the solution, allowing the initial microbial community in the microbial film to gradually adapt and begin sulfur conversion. Key indicators are an H2S removal rate exceeding 90% and a decrease in pH, indicating that the system has developed preliminary sulfur oxidation capacity (sulfur-oxidizing bacteria oxidize H2S to sulfuric acid, leading to a decrease in pH) and possesses the ability to treat hydrogen sulfide, laying the foundation for subsequent targeted acclimatization.

[0012] Step S2, by precisely controlling the rate of pH decrease, avoids acute microbial death and instead allows strains that can tolerate and adapt to the acidic environment (especially acid-tolerant autotrophic mycobacteria) to gradually gain a competitive advantage, leading to an increase in their abundance. This step prepares for subsequent extreme enrichment and efficient transformation under extreme conditions. Under harsh conditions with pH below 1.5 and sulfate concentrations ≥2 g / L, only a very small number of highly specialized microorganisms can survive and remain active. By maintaining this extreme environment, super-selectivity and enrichment of acid-tolerant autotrophic mycobacteria are achieved, resulting in an abundance of over 60% in the bacterial community. This high-purity target microbial community is the biological basis for ensuring the efficient oxidation of hydrogen sulfide to elemental sulfur and the efficient reduction of sulfate to sulfur-containing amino acids. It enables the entire system to perform specific transformation reactions with high selectivity and efficiency under extreme conditions that are difficult to achieve with traditional biological treatment methods.

[0013] Step S3, simultaneous sulfur resource recovery, is the step that achieves the final technical effect and economic benefits of this invention. Under the extremely acidic conditions established by the previous steps of domestication and enrichment, the enriched microbial community containing high abundance of *Mycobacterium* species can efficiently convert hydrogen sulfide into elemental sulfur. Simultaneously, by periodically replacing the solution and controlling the O2 / H2S gas supply ratio, the reaction environment is optimized, which not only promotes the oxidation of hydrogen sulfide but also creates conditions favorable for the reduction of sulfate ions to sulfur-containing amino acids. Finally, two high-value products—elemental sulfur (from the packing layer) and sulfur-containing amino acids (from the water collection tank solution)—are recovered.

[0014] The above-mentioned scheme successfully overcomes the pH limitation of traditional biological treatment through a sophisticated step-by-step acclimatization and precise screening strategy, enabling the system to operate stably under extremely acidic conditions. Furthermore, through the enrichment of specific microbial communities, it achieves effective treatment of toxic sulfur pollutants (H2S and SO4). 2- The simultaneous and efficient removal of sulfur and its high-value conversion into elemental sulfur and sulfur-containing amino acids achieves the dual goals of pollution control and resource recovery, demonstrating strong innovation and practicality.

[0015] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate into elemental sulfur and sulfur-containing amino acids is provided. Step S2 specifically involves: controlling the pH value of the culture medium to slowly decrease to below 1.5 in order to selectively cultivate acid-tolerant microbial communities, so that the abundance of acid-tolerant autotrophic mycobacteria reaches more than 1%; under the conditions of pH value < 1.5 and sulfate concentration ≥ 2 g / L, selectively enriching acid-tolerant autotrophic mycobacteria continues until its abundance reaches more than 60%.

[0016] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids is provided, wherein during the start-up of the biological system, the inlet load of hydrogen sulfide gas is 10-20 g / (m³). 3 •h), the initial pH of the culture medium is 7-8, and the DO value is above 5 mg / L.

[0017] During system startup, the aforementioned conditions collectively created a favorable environment for the successful acclimatization of the microbial community and the rapid formation of the biofilm. A slightly alkaline initial pH (7-8) is the optimal growth range for most activated sludge microorganisms, facilitating rapid microbial reproduction and adaptation, and reducing environmental stress. Sufficient dissolved oxygen (>5 mg / L) ensured the activity of aerobic sulfur-oxidizing bacteria, providing ample electron acceptors for the initial oxidation of hydrogen sulfide, promoting effective biofilm establishment and initial H2S removal. A moderate hydrogen sulfide inlet load (10-20 g / (m³)) was also maintained. 3 The method avoids substrate inhibition or toxicity, allowing microorganisms to gradually adapt and efficiently utilize hydrogen sulfide as an energy source. This lays a solid biological foundation for subsequent acid tolerance acclimatization and precise enrichment, ensuring a smooth start-up and initial results for the system.

[0018] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids is provided, using water as a solvent. The culture medium has the following composition: K₂HPO₄ 0.3-0.8 g / L; NH₄Cl 0.3-0.5 g / L; MgCl₂∙6H₂O 0.1-0.3 g / L; FeSO₄∙7H₂O 0.001-0.02 g / L. These components together constitute a basic mineral nutrient solution, ensuring that Mycobacterium spp. can obtain all the macro and micronutrients required for survival and to carry out its unique metabolic activities (simultaneous conversion of hydrogen sulfide and sulfate ions) under extremely acidic and high sulfate conditions.

[0019] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate into elemental sulfur and sulfur-containing amino acids is provided. In step S2, during the directional acclimatization of acid-resistant microbial communities, the pH value of the culture medium is controlled to slowly decrease to below 1.5 by gradually increasing the inlet load of hydrogen sulfide gas and simultaneously by adding acidic and / or alkaline reagents and updating the culture medium.

[0020] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids is provided, wherein in step S2, the inlet load of the hydrogen sulfide gas is 100 g / (m³). 3 •h) or more (preferably 100-300 g / (m 3 The acidic reagent is sulfuric acid; the alkaline reagent is sodium hydroxide solution.

[0021] During the directional domestication process of acid-tolerant microbial communities, the hydrogen sulfide intake load was increased to 100 g / (m³). 3 The above (h) aims to accelerate the formation of sulfuric acid in the system by increasing the sulfur oxidation reaction rate, thereby applying stronger and more sustained acidic selection pressure. This promotes the rapid adaptation of the microbial community to the low pH environment, eliminates acid-intolerant strains, and accelerates the growth of acid-tolerant strains. Simultaneously, using sulfuric acid as an acidic reagent directly simulates and enhances the acidic environment caused by the microbial's own metabolic products (sulfur oxidation to sulfuric acid), making the domestication process more targeted and accurately screening for strains that can tolerate their own acid production. Sodium hydroxide solution, as an alkaline reagent, provides the ability to finely control the pH decrease, avoiding the acute toxicity of sudden pH drops to the microorganisms. This allows the microbial community to gradually adapt and evolve under controlled, gradually increasing acidic stress, ensuring both domestication efficiency and the survival and targeted enrichment of the microbial community, ultimately achieving the successful domestication of acid-tolerant microbial communities (especially acid-tolerant autotrophic mycobacteria).

[0022] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids is provided. In step S3, more than half of the sulfate wastewater is replaced every 6-8 days, while the inlet load of the hydrogen sulfide gas is controlled at 100-300 g / (m³). 3 The molar ratio of O2 / H2S is 1.8-2.3 (·h).

[0023] In the simultaneous sulfur resource recovery process, half of the sulfate wastewater is replaced every 6-8 days. The advantage of this is that it periodically recovers the target product, sulfur-containing amino acids, while continuously replenishing the sulfate substrate, maintaining the stability of the sulfate reduction reaction, and avoiding the accumulation of metabolic byproducts or toxic substances in the solution, thus ensuring the long-term efficient operation of the system. The hydrogen sulfide inlet load is controlled at 100-300 g / (m³). 3•h) (preferably 110-130 g / (m 3 The high level of H2S (·h) allows for maximum utilization of the enriched acid-tolerant autotrophic mycobacteria, achieving high-throughput hydrogen sulfide treatment and ensuring high production of elemental sulfur. Simultaneously, precisely controlling the O2 / H2S molar ratio at 1.8-2.3 finely regulates the oxygen supply under extremely acidic conditions, optimizing the oxidation efficiency of hydrogen sulfide (ensuring its primary conversion to elemental sulfur) and maintaining optimal microbial metabolic activity. This creates a favorable microenvironment for sulfate reduction, ensuring efficient hydrogen sulfide removal, elemental sulfur production, and the simultaneous generation and recovery of sulfur-containing amino acids, achieving efficient synergy and resource utilization throughout the entire process.

[0024] Preferably, the sulfate wastewater contains SO4 2- Concentration ≥ 2 g / L.

[0025] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate into elemental sulfur and sulfur-containing amino acids is provided. In step S3, sulfur-containing amino acids are recovered from the sulfate wastewater and elemental sulfur is recovered from the packing material.

[0026] Microorganisms in biofilms generally include species such as Dechloromonas, Microfilariae, Iron Bacteria, Nitrifying Spirulina, Streptomyces marineii, Animal Gluconobacterium, Denitrifying Bacteria, Dow Bacteria, and Mycobacterium.

[0027] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate into elemental sulfur and sulfur-containing amino acids is provided. The preparation method of the packing material with attached microbial film is as follows: take polyurethane sponge cubes as packing material, immerse the packing material in activated sludge with a concentration of 20~30 g / L, and aerate through micropores for 6~8 days.

[0028] This packing material preparation method, through careful condition setting, aims to rapidly and efficiently cultivate a highly active attached microbial community. Polyurethane sponge cubes are selected as the packing material; their porous structure provides a large surface area for microbial attachment and growth, while also offering stability. Immersing them in high-concentration (20-30 g / L) activated sludge enables rapid and high-density initial microbial inoculation, significantly shortening the bioreactor start-up time. Meanwhile, 6-8 days of microporous aeration continuously provides sufficient dissolved oxygen, promoting the proliferation and activity of aerobic microorganisms while maintaining good mixing, accelerating the formation of a stable, uniform, and highly functional biofilm on the packing material surface. This combined approach ensures that the packing layer can rapidly form a highly efficient and durable bioreactor packing material, providing a sufficient and active microbial population for subsequent biological treatment processes.

[0029] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate into elemental sulfur and sulfur-containing amino acids is provided, wherein the activated sludge includes Mycobacterium genus, and the abundance of Mycobacterium genus is 0.01-0.1%.

[0030] The abundance of bacteria involved in this invention refers to the percentage of a certain bacterium in a sample relative to the total number of similar microorganisms in a microbial detection.

[0031] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate into elemental sulfur and sulfur-containing amino acids is provided. The activated sludge further includes 4-10% of *Dechloromonas*, 3-10% of *Microfilaria*, 2-8% of *Iron Bacteria*, 1-5% of *Nitrifying Spirulina*, 1-5% of *Streptomyces*, 1-3% of *Animal Gluconobacterium*, 0.6-4% of *Denitrifying Bacteria*, and 0.5-2% of *Dowella*.

[0032] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids is provided, the method being implemented through a biological desulfurization system; the present invention provides a system for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids, the biological desulfurization system comprising a biotrickling filter 8, wherein the biotrickling filter 8 is provided with a packing layer 89, and the packing layer 89 is provided with packing material with attached microbial films. The top of the bio-trickling filter tower 8 is equipped with a replenishing nozzle 83, and the lower part of the bio-trickling filter tower 8 is equipped with a water collection tank 84; the water collection tank 84 is connected to the replenishing nozzle 83; hydrogen sulfide gas is introduced into the water collection tank 84 containing culture medium, and then the culture medium is transported to the replenishing nozzle 83, sprayed from top to bottom through the packing layer 89, and then flows back to the water collection tank 84 to achieve continuous circulating dripping; The bottom of the water collection tank 84 is also equipped with an aeration head 111 to create aerobic conditions.

[0033] In the system of this invention, the bio-trickling filter tower 8 vertically integrates the three functional zones of reaction, separation, and circulation. The replenishment nozzle 83 at the top of the tower evenly sprays the culture medium from the collection tank 84 onto the packing layer 89, forming a continuous liquid film containing H2S and SO4. 2- It provides a sufficient gas-liquid-biofilm contact interface; the packing layer 89 both retains the generated elemental sulfur and serves as an immobilization packing for acid-resistant mycobacteria. The collection tank 84 simultaneously functions as a liquid storage, buffer, and post-reaction liquid collection tank; its bottom aeration head 111 continuously supplies oxygen to the liquid phase through microporous aeration, maintaining DO > 5 mg / L. -1To prevent sulfur particle deposition, the liquid in the collection tank 84 is pumped back to the replenishment nozzle 83, achieving closed-loop liquid circulation. The synergistic effect between the components in this invention enables the system to operate stably under high load even under extremely acidic conditions. Elemental sulfur and sulfur-containing amino acids are recovered in one step through packing flushing and circulating liquid replacement, respectively. The system is compact, energy-efficient, and easily scaled up.

[0034] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate into elemental sulfur and sulfur-containing amino acids is provided, wherein the bio-trickling filter 8 is further provided with a support plate 88, and the packing layer 89 is disposed on the support plate 88.

[0035] The biological trickling filter 8 suspends the packing layer 89 through the support plate 88, which not only prevents the packing from compacting and clogging under high load operation, but also ensures that the gas and liquid phases pass through the packing evenly, maintaining stable gas-liquid-biofilm three-phase contact.

[0036] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids is provided. The water collection tank 84 is further provided with a bio-trickling filter inlet 81, an exhaust port 85, and a feed port 87; the water collection tank 84 is further provided with a water outlet 86, which is connected to the replenishment nozzle 83; and the top of the bio-trickling filter 8 is further provided with a bio-trickling filter outlet 82.

[0037] The water collection tank 84 integrates the air inlet 81, vent 85, water outlet 86, and feed inlet 87 of the bio-trickling filter, enabling the replenishment, discharge, and renewal of gases, liquids, acids, alkalis, and trace elements to be completed at the same low level, reducing pipelines; the air outlet 82 of the bio-trickling filter directly discharges qualified exhaust gas, forming a compact layout of "low-level centralized operation and high-level safe exhaust".

[0038] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids is provided, wherein the biological desulfurization system further includes: Buffer bottle 6; the buffer bottle 6 is provided with a buffer bottle air inlet 61 and a buffer bottle air outlet 62; the buffer bottle air outlet 62 is connected to the air inlet 81 of the bio-trickling filter tower; Blower 1 and H2S gas cylinder 2; the blower 1 and H2S gas cylinder 2 are connected to the air inlet 61 of the buffer bottle via a three-way valve 5.

[0039] Blower 1 and H2S gas cylinder 2 are premixed, pressure stabilized, and concentration fluctuations eliminated in buffer bottle 6 via three-way valve 5. The uniformly mixed gas is then continuously fed into the inlet 81 of the bio-trickling filter tower through the outlet 62 of the buffer bottle. This front-end buffer design allows the system to precisely control the H2S load and prevent shocks. It also works in conjunction with the packing layer, replenishment nozzles, and bottom aeration in the tower to simultaneously and efficiently convert H2S and SO4 under extremely acidic conditions.2- It enables online recovery of elemental sulfur and sulfur-containing amino acids, and has advantages such as stable gas intake, uniform reaction, compact footprint, low energy consumption, and easy scale-up.

[0040] According to the present invention, a method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids is provided, wherein the biological desulfurization system further includes: Air pump 11; the air pump 11 is connected to the aeration head 111; pH / DO meter 10 is used to monitor the pH and DO values ​​in the water collection tank 84.

[0041] Air pump 11 precisely supplies oxygen to collection tank 84 through aeration head 111 to maintain the high dissolved oxygen requirement under extreme acidification conditions; pH / DO monitor 10 provides real-time feedback and regulation to ensure the system operates at pH < 1.5 and DO > 5 mg·L. -1 Even under harsh conditions, it still retains H2S and SO4 2- Synchronous and efficient conversion.

[0042] The beneficial effects of this invention are: This invention innovatively couples the sulfur oxidation and sulfate reduction metabolic pathways, achieving simultaneous and efficient conversion of hydrogen sulfide and sulfate in wastewater. This not only converts hydrogen sulfide into high-value elemental sulfur, but also utilizes the electrons and sulfate ions generated to drive the production of sulfur-containing amino acids (such as methionine and cysteine), thereby realizing the recycling of sulfur waste and energy self-sufficiency, and fundamentally and significantly improving the utilization rate and resource recovery efficiency of sulfur.

[0043] This invention utilizes a uniquely designed extremely acidic and high sulfate environment to successfully enrich and cultivate dominant bacterial groups such as autotrophic mycobacteria spp. that are resistant to extreme acids. This precisely constructed microbial system exhibits excellent stability, high activity, and effective inhibition of non-acid-resistant competitive microorganisms in harsh industrial environments, significantly improving sulfide conversion efficiency and target product yield. This opens up new avenues and broader application prospects for biotechnology in the treatment of extreme industrial waste. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the biological desulfurization system used in Embodiment 1 of the present invention.

[0046] Figure 2 In the process of simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids, as provided in Embodiment 1 of this invention, S... 0 The graph shows the changes in sulfur-containing amino acid production; graph a is the microbial community structure diagram; graph b is the relationship between sulfide consumption and sulfur content. 0 Yield graph; graph c shows sulfide consumption versus S-SO4 2- Concentration change graph; d graph is the amino acid yield graph.

[0047] Figure 3 This is a diagram showing the morphological changes of the packing material used in a method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids, as provided in Embodiment 1 of the present invention. Figure a shows the morphology before H2S gas is introduced; Figure b shows the morphology after 72 hours of H2S gas introduction; Figure c shows the morphology after rinsing. 0 Sedimentation diagram.

[0048] Figure 4 This is the system used in Comparative Example 1 of the present invention.

[0049] Figure 5 S is the method used in Comparative Example 1 of this invention. 0 Production change graph.

[0050] Figure label: 1. Blower; 2. H2S gas cylinder; 3. Pressure reducing valve; 4. Electronic flow meter; 5. T-junction; 6. Buffer bottle; 61. Buffer bottle inlet; 62. Buffer bottle outlet; 7. Rotor flow meter; 8. Biological trickling filter; 81. Biological trickling filter inlet; 82. Biological trickling filter outlet; 83. Liquid replenishment nozzle; 84. Water collection tank; 85. Drain outlet; 86. Water outlet; 87. Feed inlet; 88. Support plate; 89. Packing layer; 9. Peristaltic pump; 10. pH / DO monitor; 11. Air pump; 111. Aeration head; 12. Alkaline absorption tower; 13. Bioreactor; 14. Sedimentation tank. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0052] The methods in the following embodiments are implemented based on a biological desulfurization system, such as... Figure 1As shown, the biological desulfurization system includes: blower 1, H2S gas cylinder 2, pressure reducing valve 3, electronic flow controller 4, three-way valve 5, buffer bottle 6, rotor flow meter 7, biological trickling filter tower 8, peristaltic pump 9, pH / DO monitor 10, and air pump 11.

[0053] Among them, blower 1 provides a continuous and stable airflow to the system, diluting and carrying H2S, so as to maintain an aerobic environment inside the bio-trickling filter tower 8.

[0054] H2S cylinder 2 is used to store high-concentration hydrogen sulfide gas as a gaseous substrate for biological desulfurization reactions.

[0055] Pressure reducing valve 3 reduces the high pressure of H2S in H2S cylinder 2 to the low pressure required by the process, protecting the downstream flow meter and pipeline safety.

[0056] The electronic flow controller 4 is used to precisely regulate and display the volumetric or mass flow rate of H2S, thereby achieving digital control of the intake load. The H2S cylinder 2 is connected in sequence to the pressure reducing valve 3 and the electronic flow controller 4. The airflow from the H2S cylinder 2 is controlled by the electronic flow controller 4 to regulate the intake load of H2S.

[0057] The three-way valve 5 combines the air from the blower 1 with the H2S airflow output from the electronic flow controller 4 in a proportional manner to form a mixed gas.

[0058] Buffer bottle 6 is used to thoroughly mix, stabilize, and buffer the mixed gas, eliminating fluctuations in flow rate and concentration to ensure stable subsequent gas intake. Buffer bottle 6 has a buffer bottle inlet 61 and a buffer bottle outlet 62. Gas enters buffer bottle 6 through buffer bottle inlet 61 and exits buffer bottle 6 through buffer bottle outlet 62.

[0059] The rotor flow meter 7 is used to visually display the total gas flow rate entering the bio-trickling filter tower 8, which facilitates manual verification and process adjustment.

[0060] The biotrickling filter 8 is the main reactor, used to achieve three-phase contact of gas, liquid, and biofilm, and sulfur conversion reaction. The biotrickling filter 8 contains a support plate 88 and a packing layer 89. The packing layer 89 is an inert packing material with an acid-resistant autotrophic biofilm attached, providing a site for microbial attachment and reaction. The packing layer 89 is placed on the support plate 88, which supports the packing layer 89 and has a mesh structure, allowing gas and liquid to pass freely. The top of the biotrickling filter 8 has a biotrickling filter outlet 82, serving as the outlet for the treated exhaust gas.

[0061] The top of the bio-trickling filter 8 is equipped with a replenishment nozzle 83, which is used to evenly spray the culture medium onto the top of the packing layer 89, forming a liquid film and wetting the biofilm. The lower part of the bio-trickling filter 8 is equipped with a collection tank 84, used for storing, mixing, and buffering the circulating culture medium. The collection tank 84 is equipped with a bio-trickling filter air inlet 81, an exhaust port 85, a water outlet 86, and a feed port 87. The air inlet 81 is the mixed gas inlet; the exhaust port 85 is used for rapid drainage, cleaning, and replacement of the culture medium; the water outlet 86 serves as the circulating liquid outlet and is connected to the replenishment nozzle 83; and the feed port 87 is used to replenish fresh culture medium, add pH adjusters, or trace elements, etc. An aeration head 111 is also installed at the bottom of the collection tank 84.

[0062] The peristaltic pump 9 provides constant flow of liquid circulation power, lifting the culture medium from the collection tank 84 to the replenishment nozzle 83 at the top of the tower.

[0063] pH / DO monitoring meter 10 connects the dissolved oxygen monitoring probe and the pH monitoring probe to the pH / DO monitoring meter 10, passes through the probe port of the water collection tank 84 and is immersed below the surface of the culture medium, and monitors and reads the pH and DO values ​​of the culture medium in real time, providing data support for process control.

[0064] Air pump 11 supplies oxygen to collection tank 84 through aeration head 111 to maintain aerobic conditions in the liquid phase and meet the aerobic metabolism of mycobacteria under extreme acidification.

[0065] The activated sludge used in the following examples had a concentration of 20 g / L (meaning the dry weight of suspended solids in each liter of mixed liquor was 20 g), and the abundance of *Dechloromonas* was 6.7%, *Microphyte* was 5.6%, *Iron Bacteria* was 4.8%, *Nitrifying Spirulina* was 3.6%, *Streptomyces* was 2.9%, *Animal Gluconobacterium* was 1.3%, *Denitrifying Bacteria* was 1.3%, *Dowella* was 1.1%, and *Mycobacterium* was 0.02%.

[0066] Example 1 This embodiment provides a method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids, comprising the following steps: (1) Inoculation of sludge and packing material for biofilm formation The inoculated sludge was activated sludge from the secondary sedimentation tank of an AAO process wastewater treatment plant. The packing material used was polyurethane sponge cubes (2*2*2 cm). The activated sludge was poured into a bucket filled with polyurethane sponge packing material until the packing material was submerged. Aeration was carried out at the bottom of the bucket for 7 days. It was observed that there was obvious activated sludge attached to the packing material, indicating that biofilm formation was successful.

[0067] (2) Filler filling The biofilm-coated packing material is filled into the bio-trickling filter tower in three layers. Each layer is supported by a mesh support plate to prevent the packing layer from being compressed and causing system blockage. The packing material filling height is lower than the replenishment nozzle.

[0068] (3) System startup H2S gas is supplied from an H2S cylinder and introduced into the inlet of the bio-trickling filter (carrier gas is air) by a blower. The gas flow time in the reactor is controlled by a rotor flow meter to be between 20-40 s, and the H2S inlet load is controlled by an electronic flow controller to be between 10-20 g / (m³). 3 • h). Start the reactor's liquid circulation and monitor the pH and DO values ​​of the culture medium in the collection tank in real time. At startup, the culture medium pH is 7.4, using water as the solvent. The culture medium composition is as follows: K₂HPO₄ 0.5 g / L; NH₄Cl 0.4 g / L; MgCl₂∙6H₂O 0.4 g / L; FeSO₄∙7H₂O 0.01 g / L. Start the air pump (flow rate 0.2-0.5 L / min) to supplement the culture medium with oxygen, maintaining DO above 5 mg / L. Monitor the H₂S concentration in the inlet and outlet air daily, and refresh the culture medium every 7 days. When the H₂S removal rate reaches over 90% and the pH value of the culture medium is observed to decrease slowly, the system startup is considered successful.

[0069] (4) Targeted domestication of acid-tolerant microbial communities Gradually increase the H2S intake load of the system to 100 g / (m³) 3 • h) or more, but not exceeding 300 g / (m 3 As sulfur-oxidizing bacteria grew and accumulated within the system, the pH of the culture medium rapidly decreased, transitioning towards a highly acidic environment. Sulfuric acid and sodium hydroxide solutions were added from the feed inlet to control the slow decrease in pH. After day 40, the pH of the culture medium dropped below 1.5. During this process, biofilm samples were taken from the packing layer every week to analyze the microbial community structure until observation was conducted on day 60. Mycobacterium Abundance >1%.

[0070] (5) Acid-tolerant autotrophic mycobacteria Mycobacterium Precise enrichment Under conditions of 0.7 ≤ pH < 1.5 and 2 g / L ≤ sulfate concentration < 25 g / L, the microbial diversity in the biofilm was low, dominated by acidophilic sulfur-oxidizing bacteria and sulfate-reducing bacteria. During this process, biofilm samples were taken from the packing layer every week to analyze the microbial population structure until… Mycobacterium Dominant (abundance > 60%).

[0071] (6) with Mycobacterium Simultaneous recovery of sulfur resources as the core The system injects sulfate wastewater (from a paper mill) with a sulfate concentration of 2 g / L. Every 7 days, half of the sulfate wastewater is replaced to maintain the high sulfate substrate environment required for the reaction. Simultaneously, the H2S influent load is precisely controlled at 120 g / (m³). 3 •h) To ensure a stable supply of reactants, the O2 / H2S molar ratio in the intake air is precisely adjusted to within the range of 1.8-2.3 using a gas pump. This allows Mycobacterium species to efficiently and stably convert H2S to S. 0 These solid-state S 0 It will be stored in the biofilm and then recovered through hydraulic rinsing and sedimentation. In addition, along with the renewal of the circulating fluid, sulfur-containing amino acids (sulfur amino acids) in the solution will also be obtained simultaneously, thereby realizing diversified resource recovery of sulfur.

[0072] Figure 2 In this embodiment, S is the system 0 The graph shows the changes in sulfur-containing amino acid production; graph a shows the bacterial community structure; graph b shows the relationship between sulfide consumption and sulfur content. 0 Yield; Figure c shows the relationship between sulfide consumption and S-SO4. 2- Concentration changes; d-plot represents amino acid production; Figure 2 In this context, DO represents dissolved oxygen; ΔS represents the difference in molar amounts of sulfur at the beginning and end; Met represents methionine; Cys represents cysteine; and PCr represents creatine phosphate. It can be seen that... Mycobacterium The abundance was enriched to 98.55% ( Figure 2 a) Under these conditions, when the dissolved DO concentration is 6-7 mg / L, over 98% of the sulfur in 200 mmol of H₂S is converted to S. 0 ( Figure 2 b). Within 48 hours, when H2S consumption reaches 250 mmol ( Figure 2 c), SO4 2- The concentration decreased by approximately 9.5 mmol, while the accumulation of sulfur-containing amino acids was approximately 2 mmol (accumulation rate of approximately 21%). Figure 2 d).

[0073] Figure 3 This is a diagram showing the changes in the morphology of the packing material. Figure 3 Figure 'a' shows the morphology of H2S gas before it is introduced. Figure 3 Figure b shows the packing morphology after 72 hours of H2S gas passage. Figure 3 c is the S after rinsing 0 Precipitation diagram. It can be seen that no S was observed on the packing surface before H2S gas was introduced. 0 Accumulation; after 72 hours of H2S gas introduction, significant S-containing deposits adhered to the packing surface. 0 Particles; after rinsing, the S on the surface of the packing 0 Collected as pale yellow S0 Sediment.

[0074] The results in summary show that Mycobacterium The abundance was enriched to 98.55%, and the system achieved 98% conversion of sulfides to S. 0 Meanwhile, 21% of the sulfate is converted into sulfur-containing amino acids, which gradually accumulate in the circulating fluid.

[0075] Comparative Example 1 This comparative example provides a method for treating hydrogen sulfide gas, which is based on... Figure 4 The system shown is implemented. The system includes an alkaline absorption tower 12, a bioreactor 13, and a sedimentation tank 14. The alkaline absorption tower 12 is responsible for absorbing H2S gas, converting it from a gaseous state to an aqueous solution (H2S(aq)), completing the initial conversion of H2S. An equilibrium reaction of hydrogen sulfides occurs within the tower, and liquid circulation is present. The bioreactor 13 receives the liquid from the alkaline absorption tower 12, aerates it, and promotes the biological oxidation reaction of HS⁻, oxidizing HS⁻ into elemental sulfur S. 0 And OH⁻, maintaining the alkaline environment of the system. Liquid circulation also exists within this device. Sedimentation tank 14 is responsible for settling and separating elemental sulfur generated in bioreactor 13, removing S from the system. 0 .

[0076] The method for this comparative example includes the following steps: (1) In the alkaline absorption tower 12, the gas to be treated containing H2S enters from the bottom and comes into countercurrent contact with the circulating alkaline liquid, so that the gaseous H2S is absorbed and dissolved in the liquid phase to form HS. - and H + The treated gas, free of H2S, is then discharged from the top of the tower.

[0077] (2) Rich in HS - The liquid is pumped to bioreactor 13, where O2 is introduced through aeration to maintain DO at 0.1-0.2 mg / L. Under the action of specific sulfur bacteria, HS... - It is oxidized into S, which is insoluble in water. 0 and OH - .

[0078] (3) The suspension after the reaction flows into the sedimentation tank 14, and the generated S is settled by gravity. 0 The sediment is collected from the bottom, while the supernatant is returned to the bioreactor or partially returned to the absorption tower, forming a complete recycling system.

[0079] Long-term performance analysis shows that, Figure 5 As shown, during the 214-day operating cycle, S was achieved by maintaining DO at 0.1~0.2 mg / L.0 The recovery efficiency reaches 75%. It should be noted that this reaction requires strict control of the O2 to H2S ratio to ensure that the product is S. 0 Instead of SO4 2- Simultaneously, the reaction must be carried out continuously in an alkaline environment. Furthermore, this device is only suitable for S... 0 The recycling process cannot recover sulfur-containing amino acids.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids, characterized in that, include: In aerobic conditions, with pH < 1.5 and SO42- 2- Under conditions of concentration ≥2 g / L, by enriching microbial communities containing Mycobacterium genus, the oxidation reaction of hydrogen sulfide and the reduction reaction of sulfate are carried out simultaneously to obtain elemental sulfur and sulfur-containing amino acids.

2. The method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids according to claim 1, characterized in that, Includes the following steps: Step S1: Under aerobic conditions, hydrogen sulfide gas is introduced into a culture medium containing sulfate, while the culture medium is continuously circulated and dripped in a packing material with a microbial film attached, until the hydrogen sulfide gas removal rate reaches more than 90% and the pH value of the culture medium begins to decrease. Step S2: Control the pH of the culture medium to slowly decrease to below 1.5, and culture the microbial community under the conditions of pH < 1.5 and sulfate concentration ≥ 2 g / L until the abundance of Mycobacterium reaches more than 60%. Step S3: Under the condition of pH < 1.5, add sulfate wastewater and periodically replace the sulfate wastewater, control the O2 / H2S gas supply ratio, so that the oxidation reaction of hydrogen sulfide and the reduction reaction of sulfate can proceed simultaneously.

3. The method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids according to claim 2, characterized in that, In step S1, the inlet load of hydrogen sulfide gas is 10-20 g / (m³). 3 •h), the initial pH of the culture medium is 7-8, and the DO value is above 5 mg / L.

4. The method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids according to claim 2 or 3, characterized in that, Using water as a solvent, the culture medium has the following composition: K2HPO4 0.3-0.8 g / L; NH4Cl 0.3-0.5 g / L; MgCl2∙6H2O 0.1-0.3 g / L; FeSO4∙7H2O 0.001-0.02 g / L.

5. The method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids according to any one of claims 2-4, characterized in that, In step S2, the pH of the culture medium is controlled to slowly decrease to below 1.5 by gradually increasing the intake load of hydrogen sulfide gas and by adding acidic and / or alkaline reagents and updating the culture medium.

6. The method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids according to claim 5, characterized in that, In step S2, the inlet load of the hydrogen sulfide gas is 100 g / (m³). 3 •h) or above; the acidic reagent is sulfuric acid; the alkaline reagent is sodium hydroxide solution.

7. The method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids according to any one of claims 2-6, characterized in that, In step S3, more than half of the sulfate wastewater is replaced every 6-8 days, while the inlet load of the hydrogen sulfide gas is controlled at 100-300 g / (m³). 3 ·h), the O2 / H2S molar ratio is 1.8-2.3; And / or, in step S3, sulfur-containing amino acids are recovered from the sulfate wastewater, and elemental sulfur is recovered from the packing material.

8. The method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids according to any one of claims 2-7, characterized in that, The preparation method of the packing material with attached microbial film is as follows: take polyurethane sponge cubes as packing material, immerse the packing material in activated sludge with a concentration of 20~30 g / L, and aerate through micropores for 6~8 days.

9. The method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids according to claim 8, characterized in that, The abundance of Mycobacterium in the activated sludge was 0.01-0.1%.

10. The method for simultaneously converting hydrogen sulfide and sulfate ions into elemental sulfur and sulfur-containing amino acids according to any one of claims 2-9, characterized in that, The method is implemented using a biological desulfurization system; The biological desulfurization system includes a biological trickling filter (8), which is provided with a packing layer (89) and the packing layer (89) is provided with packing material with attached microbial film. The top of the biological trickling filter (8) is provided with a replenishing nozzle (83), and the bottom of the biological trickling filter (8) is provided with a water collection tank (84); the water collection tank (84) is connected to the replenishing nozzle (83); hydrogen sulfide gas is introduced into the water collection tank (84) containing the culture medium, and then the culture medium is transported to the replenishing nozzle (83), sprayed from top to bottom through the packing layer (89), and then flows back to the water collection tank (84) to achieve continuous circulating trickling; The bottom of the water collection tank (84) is also equipped with an aeration head (111) to create aerobic conditions.

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