A method for treating wastewater containing perfluoroalkyl and polyfluoroalkyl substances using sulfur mediation sludge treatment

Abstract

The application discloses a method for treating wastewater containing perfluoroalkyl and polyfluoroalkyl compounds by using sulfur-mediated sludge, and the method comprises the following steps: culturing mature and stable sulfur-mediated sludge in a SRUSB reactor, gradually domesticating microbial communities to adapt to the environment with high concentration of perfluoroalkyl and polyfluoroalkyl compounds, and realizing efficient degradation of PFOS and FOSA, and the removal rate reaches 100%. By optimizing the culture and operation conditions of the sulfur-mediated sludge, the application not only significantly reduces the energy consumption, but also reduces the sludge yield and operation cost. By adopting a scientific phased domestication strategy, the application gradually increases the concentration of perfluoroalkyl and polyfluoroalkyl compounds, and cultivates sulfur-mediated sludge with strong tolerance and degradation capacity. It is found that under the condition of no external nutrient supplement, the sludge can realize efficient degradation of PFOS and FOSA through its own metabolic mechanism, and especially under the condition of no supplement, the sludge shows better degradation effect, and exhibits its adaptability and potential application value in the resource-limited environment.

Description

Technical Field

[0001] This invention belongs to the field of biological wastewater treatment. Specifically, it relates to a method for treating wastewater containing perfluorinated and polyfluoroalkyl compounds using sulfur-mediated sludge. The perfluorinated and polyfluoroalkyl compounds include conventional perfluorinated and polyfluoroalkyl compounds (PFOS) and novel perfluorinated and polyfluoroalkyl compounds (FOSA). This method is applicable to the field of wastewater treatment containing perfluorinated and polyfluoroalkyl compounds. Background Technology

[0002] Per- and poly-fluoroalkyl substances (PFAS), as a typical class of emerging pollutants, are increasingly attracting global attention due to their wide application and characteristics such as environmental persistence, recalcitrant nature, bioaccumulation, and toxicity. Because of the high stability of the carbon-fluorine bond, traditional PFAS have been gradually phased out, and a series of novel PFAS have been developed as alternatives. However, these novel PFAS also exhibit unpredictable toxicity, and are even more recalcitrant and mobile than traditional PFAS. To date, more than 10,000 different types of PFAS have been detected worldwide, widely present in various environmental media, including drinking water, river water, various wastewaters, landfills, and marine ecosystems, with concentrations ranging from ng / L to mg / L, posing a serious threat to the ecological environment and human health. Since some PFAS are indispensable in applications, and no fluorine-free alternatives have yet been found, there is an urgent need for cost-effective PFAS remediation technologies and the development of novel fluorine-containing alternatives with high degradability and the same functions.

[0003] Due to the high bond energy of carbon-fluorine bonds, the degradation or defluorination of PFAS currently relies mainly on physicochemical methods, including advanced oxidation processes (AOPs) such as electrochemical oxidation, photolysis, and ultraviolet-induced oxidation, as well as advanced reduction processes (ARPs), membrane processes, carbon adsorption, nano-adsorption, and plasma technologies. These technologies generally have drawbacks, such as high cost, high energy consumption, and the potential generation of toxic conversion products. Compared to physicochemical methods, biological methods have always been a key technology for wastewater treatment due to their cost-effectiveness, environmental friendliness, and sustainable development advantages. In recent years, research on microbial degradation of PFAS and the potential impact of PFAS on wastewater biological systems has become a research hotspot in the environmental field. According to thermodynamic calculations, the reductive defluorination of fluorinated compounds is biologically feasible. Existing studies have shown that microbial defluorination can be observed in polyfluorinated telomere structures (i.e., fluorinated compounds containing CH2 molecules) under both aerobic and anaerobic conditions. Huang et al. reported that Acidimicrobium sp. Strain A6, using ammonium or hydrogen as electron donors, can defluorinate perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) simultaneously while reducing iron (Defluorination of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) by Acidimicrobium sp. Strain A6. Environmental Science & Technology, Volume 53, 2019, ISSN 0013-936X). Furthermore, Yu et al. discovered that two C6 perfluorinated and polyfluoroalkyl compounds can undergo reductive defluorination through organohalogen-respiring microbial communities (Microbial Defluorination of Unsaturated Per- and Polyfluorinated Carboxylic Acids under Anaerobic and Aerobic Conditions: A Structure Specificity Study. Environmental Science & Technology, Volume 56, 2022, ISSN 0013-936X).Recently, Jin et al. reported a novel pathway for the spontaneous defluorination of chlorofluorocarboxylic acids (Cl-PFCA) initiated by anaerobic microbial dechlorination, with a high enrichment of anaerobic defluorinating microorganisms, primarily *Desulfovibrio aminophilus* and *Sporomusa sphaeroides* (Substantial defluorination of polychlorofluorocarboxylic acids triggered by anaerobic microbial hydrolytic dechlorination. *Nature Water*, Volume 1, 2023, ISSN 2731-6084). These studies demonstrate the feasibility of microbial degradation of PFAS.

[0004] In recent years, a novel sulfur-mediated biological treatment technology has been developed and widely applied in the treatment of domestic sewage in coastal cities and saline industrial wastewater due to its advantages such as low energy consumption, good treatment effect, and low sludge production. However, in practical applications, we have found that compared with traditional aerobic and anaerobic sludge systems, sludge systems based on sulfate-reducing bacteria (SRB) exhibit excellent tolerance and high removal efficiency to antibiotic-resistant recalcitrant pollutants, indicating that sulfur-mediated sludge systems have good potential for the removal of recalcitrant pollutants. However, current sulfur-mediated biological treatment technologies are only used to treat wastewater with high sulfate content (such as seawater). There are also no studies reporting on the removal of PFAS by sulfur-mediated biological systems or the mechanism by which PFAS affects sulfur-mediated biological systems. Therefore, finding a sulfur-mediated biological system-based treatment process to effectively degrade PFAS in wastewater containing perfluorinated and polyfluoroalkyl compounds while maintaining / improving system stability remains a pressing problem in this field. Summary of the Invention

[0005] To address the shortcomings and deficiencies of existing technologies, the primary objective of this invention is to provide a method for treating wastewater containing traditional perfluorooctane sulfonic acid (PFOS) and novel perfluorooctane sulfonamide (FOSA) using sulfur-mediated sludge, achieving efficient degradation and removal of PFAS and effectively reducing the PFAS content in the effluent. This invention utilizes sulfur-mediated sludge, which solves the problems of high energy consumption, large sludge production, large land area requirements, and over-reliance on the coupling and superposition of multiple wastewater treatment processes in existing wastewater treatment plants. Simultaneously, the use of sulfur-mediated sludge reduces construction and maintenance costs and provides a feasible solution for treating wastewater containing both traditional and novel PFAS. The wastewater treatment method of this invention is simple, low-cost, and highly operable.

[0006] Another object of the present invention is to provide an application of the above-described water treatment method.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A method for treating wastewater containing conventional perfluorinated and polyfluorinated alkyl compounds (PFOS) or novel perfluorinated and polyfluorinated alkyl compounds (FOSA) using sulfur-mediated sludge includes the following steps:

[0009] (1) Cultivation of sulfur-mediated sludge: Sulfate-reducing bacteria activated sludge was inoculated into an upflow sulfate reduction anaerobic sludge bed reactor (SRUSB) and operated in the following mode: influent, anaerobic, reduction, and effluent; artificially synthesized wastewater containing carbon, nitrogen, sulfur, phosphorus and trace elements was introduced into the reactor. During this period, the composition of the influent was precisely controlled to ensure that the mass concentration ratio of carbon, nitrogen and phosphorus was always maintained in the range of 98-100:8-10:0.8-1.

[0010] (2) Start the first stage: After completing step (1), when the sulfate (SO4) in the reactor... 2- When the removal rate reaches 90% and the chemical oxygen demand (COD) removal rate reaches 95%, a portion of the mature sulfur-mediated sludge is taken out from the reactor and placed in an experimental vial. Traditional perfluorinated and polyfluoroalkyl compounds (PFOS) or novel perfluorinated and polyfluoroalkyl compounds (FOSA) are added to the vial. The concentration of PFOS or FOSA added is 0.95-1 mg / L. The operating conditions and water distribution conditions are exactly the same as those in the sludge cultivation stage of step (1). The system is operated according to the mode described in step (1) for 35-40 days. During this period, the effluent indicators are monitored regularly, including sulfate removal rate, COD removal rate, degradation of perfluorinated and polyfluoroalkyl compounds, and microbial activity, in order to evaluate the effect of acclimatization and cultivation.

[0011] (3) Start the second stage: Based on step (2), further increase the concentration of traditional perfluorinated and polyfluoroalkyl compounds (PFOS) or novel perfluorinated and polyfluoroalkyl compounds (FOSA) in the vial to 9.5-10 mg / L; its operating conditions and water distribution conditions are exactly the same as those of the sludge cultivation stage in step (1), and operate in the mode described in step (1) for 145-165 days. During this period, monitor the effluent indicators regularly, including sulfate removal rate, COD removal rate, degradation of perfluorinated and polyfluoroalkyl compounds, and microbial activity, until the removal rate of perfluorinated and polyfluoroalkyl compounds remains stable.

[0012] In step (1), the sulfate-reducing bacteria activated sludge is sludge containing abundant sulfate-reducing bacteria (SRB).

[0013] In steps (1) to (3), the operating modes include water inlet, anaerobic, reduction, and drainage. Throughout the operation, the temperature is maintained at 35–37°C, and the pH is maintained at 6.8–7.5.

[0014] In steps (1) to (3), the artificially synthesized wastewater contains carbon source, nitrogen source, sulfur source, phosphorus source and trace elements; wherein, the carbon source is provided by glucose and sodium acetate, the sulfur source is anhydrous sodium sulfate, the phosphorus source is provided by K2HPO4 and KH2PO4, and the nitrogen source is NH4Cl; the initial concentration of sulfur source in the wastewater is 270-280 mg / L, the initial concentration of COD is 490-510 mg / L, the initial concentration of phosphorus source is 3-5 mg / L, the initial concentration of nitrogen source is 15-20 mg / L, and the pH of the wastewater is adjusted to 6.8-7.5 with hydrochloric acid and sodium hydroxide solution, and the optimal pH is 7.0.

[0015] In steps (1) to (3), the addition of trace elements refers to the addition of a trace element stock solution. The trace element stock solution is prepared by adding trace elements to tap water. The volume ratio of trace elements to tap water is 1 mL / L. The trace element components and their contents are ZnSO4 0.12-0.13 g / L, MnCl2·4H2O 0.12-0.13 g / L, and (NH4)6Mo7O 24 ·4H2O0.07-0.09g / L, CuSO4·5H2O 0.03-0.05g / L, CoCl2·6H2O 0.15-0.16g / L, NiCl2 0.10-0.12g / L, EDTA 0.06-0.08g / L, KI 0.18-0.20g / L and H3BO3 0.10-0.11g / L.

[0016] In step (1), the reactor is an upflow sulfate reduction anaerobic sludge bed reactor (SRUSB) made of plexiglass. The device consists of an inlet / outlet water system, a reaction zone, and an internal circulation system, employing a bottom inlet and overflow outlet design. The main components of the reactor include sampling valves and pipes, inlet / outlet water tanks, inlet / outlet water pumps, internal circulation pumps and pipes, inlet valve, oxidation-reduction potential (ORP) and pH probes and their main units, and the reactor body.

[0017] Wastewater enters the reactor from the bottom via a peristaltic pump at a set flow rate (15.0–16.0 mL / min), and effluent is discharged through an overflow pipe. Sulfate-reducing bacteria activated sludge is added in a sludge-water mixture.

[0018] Specifically, this invention provides a method for treating wastewater containing conventional perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonamide (FOSA) using sulfur-mediated sludge, comprising the following specific steps:

[0019] (1) Cultivation of Sulfur-Mediated Sludge: To achieve effective cultivation of anaerobic sulfur-mediated sludge, sulfate-reducing bacteria activated sludge was first introduced into the reactor as the core microbial population. A stable anaerobic environment was maintained by adjusting the pH value within the reactor, providing suitable conditions for the growth and metabolism of sulfate-reducing bacteria. Subsequently, synthetic wastewater containing carbon, nitrogen, sulfur, phosphorus, and trace elements was introduced into the reactor to ensure sufficient nutrients for the microorganisms. Through this process, the microbial community in the sludge was gradually acclimated, adapting to the sulfur-centered environment and forming a relatively stable sulfur cycle system. In the initial stage of reactor startup, the focus was on improving sulfur conversion efficiency, especially the reduction effect of sulfate. Therefore, no new organic micropollutants were introduced during this stage to avoid interfering with the adaptability and activity of the microbial community. By strictly controlling the reactor's operating conditions, the sulfate-reducing bacteria in the sludge were able to fully utilize their metabolic functions, gradually establishing a highly efficient sulfur conversion capacity. The entire cultivation process lasts approximately 1.5 to 2 months. During this period, the composition of the influent is precisely controlled to ensure that the mass concentration ratio of carbon, nitrogen, and phosphorus is maintained within the range of 98–100:8–10:0.8–1, in order to meet the growth requirements of microorganisms and maintain the stability of the system.

[0020] (2) Start the first stage: After completing step (1), when the sulfate (SO4) in the reactor... 2-When the removal rate reaches 90% and the chemical oxygen demand (COD) removal rate reaches 95%, a portion of the mature sulfur-mediated sludge is removed from the reactor and placed in a small vial. A traditional perfluorinated and polyfluoroalkyl substances (PFOS) or a novel perfluorinated and polyfluoroalkyl substances (FOSA) are added to the vial. A separate vial is reserved as a blank control. The initial water formulation in the vial is consistent with that of the parent reactor to ensure comparability and consistency of experimental conditions. The reactor is operated according to the following mode: the operation process includes influent, anaerobic, reduction, and effluent. Subsequently, the experiment enters the first startup stage. In the second stage, the anaerobic sulfate reduction activated sludge is further acclimatized and cultivated for 1 to 2 months. During this stage, influent containing carbon, sulfur, phosphorus, nitrogen, trace elements, and perfluorinated and polyfluoroalkyl substances is introduced into the reactor, officially starting the anaerobic sulfate reduction process and simultaneously removing organic pollutants. To avoid the inhibitory effect of high concentrations of pollutants on microbial activity, the initial concentration of emerging organic micropollutants (PFOS or FOSA) in the influent is set at a low level (95–100 μg / L) to promote the gradual adaptation of microorganisms to the environment containing perfluorinated and polyfluoroalkyl compounds (PFOS). Furthermore, the mass concentration ratio of carbon, nitrogen, and phosphorus in the influent is strictly controlled at 98–100:8–10:0.8–1 to provide a suitable nutrient ratio for microbial growth and metabolism. During this stage, the sludge is gradually acclimated to the PFOS and FOSA environment through continuous operation and optimization of reactor conditions. Key parameters, including sulfate removal rate, COD removal rate, degradation of PFOS and FOSA, and microbial activity, need to be monitored regularly to assess the effectiveness of the acclimation cultivation. Through this process, the cultivated anaerobic sulfate-reducing sludge not only maintains a high sulfate-reducing capacity but also possesses the ability to stably degrade organic pollutants in an environment containing PFOS and FOSA.

[0021] (3) Initiating the second stage: After completing step (2), the activated sludge, which has been acclimated for a period of time, is subjected to a water exchange operation. The water exchange formula is consistent with the influent formula in steps (1) and (2) to ensure the continuity and comparability of experimental conditions. Subsequently, the sludge is divided into two experimental systems, and different perfluorinated and polyfluoroalkyl compounds (PFOS and FOSA) are subjected to degradation experiments. The specific operation is as follows:

[0022] Group A (PFOS experimental group): The PFOS concentration in the influent of 6 small bottles was increased to 9.5-10 mg / L to investigate the sulfur-mediated degradation capacity of sludge under high concentration PFOS environment.

[0023] Group B (FOSA experimental group): The FOSA concentration in the influent of 6 small bottles was increased to 9.5-10 mg / L to explore the sulfur-mediated degradation capacity of sludge under high concentration FOSA environment.

[0024] The reactor operated continuously for approximately 145–165 days according to the operating mode described in step (2), during which PFOS and FOSA degradation experiments were conducted on the sludge in the vials. Wastewater samples were collected and the concentration changes of PFOS and FOSA were detected to analyze their degradation patterns.

[0025] In step (1), after inoculation, to ensure the normal growth and metabolism of sulfate-reducing bacteria (SRB) and the stable operation of the reaction in the reactor, artificially synthesized wastewater was used as the reactor influent, and its water quality composition and operating conditions were strictly controlled. The carbon source of the influent was provided by glucose and sodium acetate, and the chemical oxygen demand (COD) was approximately 500 mg / L, ensuring a sufficient supply of organic matter to meet the energy needs of the microorganisms. The sulfur source was provided by adding anhydrous sodium sulfate (Na2SO4), and the sulfate concentration was controlled (using SO42-) 2- The concentration of phosphorus (based on sulfur dioxide) was approximately 270–280 mg / L, providing the necessary electron acceptor for the sulfate reduction reaction. Potassium dihydrogen phosphate (KH₂PO₄) and dipotassium hydrogen phosphate (K₂HPO₄) were used as the phosphorus source, while ammonium chloride (NH₄Cl) was provided as the nitrogen source. The phosphorus was precisely formulated according to a carbon, nitrogen, and phosphorus ratio (C:N:P = 98–100:8–10:0.8–1) to meet the nutrient requirements for microbial growth. To prevent acidification of the influent during storage or operation due to microbial activity or other chemical processes, an appropriate amount of sodium bicarbonate (NaHCO₃) was added to stabilize the pH of the influent, maintaining it within the neutral range (approximately 7.0), providing a suitable environment for SRB growth. Furthermore, to further meet the micronutrient requirements of the microorganisms during metabolism, various trace elements such as iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn) were added to the synthetic wastewater to promote microbial activity and stability.

[0026] In step (1), the reactor is an upflow sulfate reduction anaerobic sludge bed reactor (SRUSB) made of plexiglass. The device consists of an inlet / outlet water system, a reaction zone, and an internal circulation system, employing a bottom inlet and overflow outlet design. The main components of the reactor include sampling valves and pipes, inlet / outlet water tanks, inlet / outlet water pumps, internal circulation pumps and pipes, inlet valve, oxidation-reduction potential (ORP) and pH probes and their main units, and the reactor body.

[0027] The optimal reaction volume of the SRUSB reactor is 1.5 liters, and the influent volume of the synthetic wastewater is 5 liters. In step (1), the carbon source in the synthetic wastewater is glucose and sodium acetate, the sulfur source is anhydrous sodium sulfate, the phosphorus source is provided by K2HPO4 and KH2PO4, and the nitrogen source is NH4Cl. Simultaneously, various trace elements, including iron, copper, manganese, zinc, cobalt, potassium, and iodine, are added to the wastewater to meet the growth requirements of microorganisms. The chemical oxygen demand (COD) of the wastewater is approximately 490–510 mg / L, and the sulfate concentration (SO4) is... 2- The concentration of -S) is approximately 270–280 mg / L, and the phosphate (P-HPO4) content is approximately 270–280 mg / L. 2- H2PO4 - The initial concentrations of ammonia nitrogen (N-NH4) were all 3-5 mg / L. + The initial concentration of the solution is 15–20 mg / L, and the pH value is adjusted to 6.8–7.5 to maintain a neutral environment.

[0028] In steps (1) to (3), the addition of trace elements refers to the addition of a trace element stock solution. The trace element stock solution is prepared by adding trace elements to tap water. The volume ratio of trace elements to tap water is 1 mL / L. The trace element components and their contents are ZnSO4·7H2O 0.12-0.13 g / L, MnCl2·2H2O 0.12-0.13 g / L, and (NH4)6Mo7O 24 ·4H2O0.07-0.09g / L, CuSO4·5H2O 0.03-0.05g / L, CoCl2·6H2O 0.15-0.16g / L, NiCl2 0.10-0.12g / L, EDTA 0.06-0.08g / L, KI 0.18-0.20g / L and H3BO3 0.10-0.11g / L.

[0029] The perfluorinated and polyfluoroalkyl compounds mentioned in steps (2) and (3) are respectively conventional perfluorinated and polyfluoroalkyl compounds (PFOS) and novel perfluorinated and polyfluoroalkyl compounds (FOSA).

[0030] In the reaction system described in step (1), the concentration of SRB activated sludge is 15–18 g MLSS / L, and the ratio of volatile suspended solids to total suspended solids (MLVSS / MLSS) of the sludge is 0.8–0.9. The COD to sulfate (S) addition ratio of the wastewater is 1.6–1.8. The pH of the reaction system is adjusted by adding dilute hydrochloric acid or sodium hydroxide solution and controlled within the range of 6.8–7.5.

[0031] The concentration of perfluorinated and polyfluoroalkyl compounds in the wastewater to be treated in step (2) is 95-100 μg / L, and the concentration of perfluorinated and polyfluoroalkyl compounds is gradually increased to 950-1000 μg / L as the operating time is extended.

[0032] In steps (1) to (3), in order to ensure that the water quality does not change too much, the incoming water should be changed at the same time every day, and a trace element diluent should be introduced before the incoming water is introduced.

[0033] Step (2) Based on step (1), take a portion of the mature sulfur-mediated sludge and place it in a 200mL experimental vial. Control the sludge concentration at 4.8-5g / L. The operating conditions and water distribution conditions are exactly the same as those in the cultivation stage.

[0034] Step (3) Building upon Step (2), further experiments on the degradation of high-concentration perfluorinated and polyfluoroalkyl compounds are conducted. The experimental conditions remain consistent with the previous steps, except that the concentrations of PFOS or FOSA in the influent are adjusted to higher levels. By precisely controlling other conditions, the impact of perfluorinated and polyfluoroalkyl compound concentrations on the sulfur-mediated sludge degradation capacity can be evaluated independently.

[0035] The 200mL vials used in steps (2) and (3) are made of polypropylene, which can adsorb perfluorinated and polyfluoroalkyl compounds to a lower limit, thereby ensuring the smooth progress of biodegradation.

[0036] This invention proposes a method for treating wastewater containing traditional per- and polyfluoroalkyl substances (PFOS) and novel per- and polyfluoroalkyl substances (FOSA) using sulfur-mediated sludge. To further investigate whether sulfur-mediated sludge enhances its degradation capacity of PFOS through its own metabolism or other methods without external nutrient supplementation, two conditions were set up in the experiment: a group with periodically supplemented carbon and sulfur sources (hereinafter referred to as the "supplemented group") and a group without supplemented carbon and sulfur sources (hereinafter referred to as the "non-supplemented group"). The degradation effects of PFOS and FOSA were compared and analyzed. In group A (with added PFOS), the experimental results showed that the PFOS removal rate reached approximately 45.5% on day 20, indicating that the sulfur-mediated sludge had a certain degradation capacity for PFOS in the early stage. By day 50, the removal rate further increased to approximately 50.1%, with a relatively slow increase. As the operating time extended, the degradation capacity of the sludge continuously increased, finally reaching a removal rate of 99.5% on day 150, achieving almost complete degradation. In the non-supplemented group, the PFOS removal rate was around 38% on day 20, slightly lower than that of the supplemented group. However, by day 50, the removal rate significantly increased to around 64%, significantly higher than that of the supplemented group. This indicates that without the supplementation of carbon and sulfur sources, the sludge may degrade PFOS more efficiently through its own metabolism or other mechanisms. Finally, on day 150, the removal rate of the non-supplemented group reached 99.6%, close to the final removal rate of the supplemented group. However, throughout the entire operation, the degradation effect of the non-supplemented group was consistently better than that of the supplemented group.

[0037] In group B, which included FOSA, the experimental results showed that the FOSA removal rate increased over time in both groups, but the degradation effect of the non-supplemented group was significantly better than that of the supplemented group, especially in the early stages. In the supplemented group, the FOSA removal rate reached 62.2% on day 20, demonstrating the strong degradation ability of sulfur-mediated sludge for FOSA; by day 50, the removal rate increased to 72.1%, and finally reached 99.9% on day 150, achieving almost complete degradation. In the non-supplemented group, the FOSA removal rate was already as high as 80.6% on day 20, significantly higher than that of the supplemented group; by day 50, the removal rate further increased to 97.5%, far higher than that of the supplemented group, and finally achieved complete degradation on day 150, with a removal rate of 100%. Overall, the degradation efficiency of FOSA was significantly higher than that of PFOS, and the non-supplemented group showed higher degradation efficiency throughout the entire operation. The experimental results show that the removal patterns of PFOS and FOSA are somewhat similar, but the degradation efficiency of FOSA is generally higher than that of PFOS, especially in the non-supplemented group.

[0038] This invention utilizes sulfate-reducing bacteria (SRB) as the key microorganism in the reactor, achieving efficient removal of perfluorinated and polyfluoroalkyl compounds (PFOS) through the synergistic effect of sulfate-reduced sulfides and sulfur-mediated sludge. Sulfate-reducing bacteria are a type of microorganism widely distributed in anaerobic environments, possessing a unique metabolic mechanism capable of using sulfates or other sulfides as electron acceptors to oxidize and decompose organic matter through sulfate reduction reactions. These bacteria can utilize not only simple small-molecule organic molecules (such as acetic acid and lactic acid) as electron donors but also metabolize more complex organic compounds, such as alkanes, long-chain fatty acids, and aromatic compounds. This diverse metabolic capacity makes them valuable for the degradation of complex pollutants. In this invention, sulfate-reducing bacteria reduce sulfates to sulfides through sulfate reduction reactions, simultaneously degrading organic pollutants. This process not only removes traditional organic pollutants but also, through synergistic action with sulfur-mediated sludge, effectively degrades difficult-to-treat perfluorinated and polyfluoroalkyl compounds (such as PFOS and FOSA). The role of sulfur-mediated sludge in this invention is mainly reflected in two aspects: Firstly, sulfides in the sludge may undergo chemisorption with perfluorinated and polyfluoroalkyl (PFOA) compounds, reducing their biotoxicity and improving their biodegradability. Secondly, the rich microbial community in the sludge, especially sulfate-reducing bacteria, further decomposes the molecular structure of PFOA compounds through biodegradation, achieving complete removal of pollutants. Furthermore, this invention optimizes reactor operating conditions, such as controlling sulfate concentration and maintaining suitable oxidation-reduction potential (ORP) and pH, providing an optimal environment for the growth and metabolism of sulfate-reducing bacteria. In this system, sulfate-reducing bacteria not only participate in pollutant degradation but also further promote the removal of PFOA compounds through the generation of metabolites (such as hydrogen sulfide). It is worth noting that this invention combines the metabolic characteristics of sulfate-reducing bacteria with the physical adsorption advantages of sulfur-mediated sludge, forming a highly efficient and synergistic removal mechanism that exhibits excellent removal effects on perfluorinated and polyfluoroalkyl (PFOA) compounds. These PFOA compounds are not limited to PFOS and FOSA as described in this invention, but are also applicable to other structurally similar PFOA compounds. This method not only significantly improves the degradation efficiency of PFOA compounds but also possesses strong shock resistance, enabling it to adapt to the treatment needs of different types of wastewater.

[0039] The sulfate reduction reaction is as follows:

[0040] 100g COD + 150.2g SO4 2- +47.3g H2O→53.2g H2S+1.9g slugde+190.9g HCO 3-

[0041] Compared with the prior art, the present invention has the following significant advantages and beneficial effects:

[0042] This invention is the first to apply sulfur-mediated sludge to the grouped treatment of traditional and novel perfluorinated and polyfluoroalkyl (PFOS and FOSA) compounds, revealing its degradation patterns and mechanisms under different nutrient conditions and demonstrating the significant advantages of sulfur-mediated sludge in degrading PFOS and FOSA. Experiments show that the sludge performance remained stable during operation, and its ability to remove other basic pollutants was not significantly affected while degrading PFOS and FOSA. Specifically:

[0043] First, this invention employs an upflow sulfate-reducing upflow sludge bed (SRUSB) reactor. The reaction process takes place under anaerobic conditions, resulting in a simple and easy-to-operate process that effectively reduces operational complexity and management costs. Through optimized anaerobic reaction conditions, this invention significantly improves the degradation efficiency of perfluorinated and polyfluoroalkyl compounds (PFOS and FOSA, etc.) and drastically shortens treatment time. Compared with traditional treatment methods, this highly efficient approach not only achieves complete removal of pollutants but also significantly reduces energy and material consumption, improving overall economic efficiency. Second, this invention adopts a scientific, phased acclimatization strategy during reactor start-up. Specifically, the sulfur-mediated sludge is first initially acclimatized to enhance its adaptability and activity to the sulfate reduction reaction; subsequently, based on the addition of perfluorinated and polyfluoroalkyl compounds, further acclimatization is performed to enhance the sulfur-mediated sludge's ability to degrade perfluorinated and polyfluoroalkyl compounds. This phased acclimatization process effectively improved the stability and degradation performance of the sulfur-mediated microbial community, laying a solid foundation for the efficient and stable removal of perfluorinated and polyfluoroalkyl (PFOA) compounds in subsequent operations. Furthermore, through enhanced cultivation and functional optimization of key microorganisms in the sulfur-mediated sludge, this invention significantly improved the removal efficiency of organic pollutants, ensuring the long-term stability and reliability of the entire process. Moreover, the sulfur-mediated sludge in this invention exhibits excellent degradation capabilities for both traditional PFOA and polyfluoroalkyl (PFOS) compounds and novel PFOA compounds (FOSA) compounds. This is attributed to the synergistic effect of sulfate-reducing bacteria (SRB) and their metabolites, which effectively disrupts the molecular structure of PFOA and polyfluoroalkyl compounds, ultimately achieving complete degradation. Compared to traditional methods such as physical adsorption or chemical oxidation, this invention, through the dual action of biodegradation and sulfur-mediated adsorption, not only improves degradation efficiency but also avoids secondary pollution. Furthermore, the technical solution of using sulfur-mediated sludge to treat PFOA and polyfluoroalkyl pollutants has significant economic and environmental advantages. This method boasts low material and energy consumption during operation, while producing minimal sludge, thus avoiding the subsequent treatment issues of residual sludge in traditional wastewater treatment processes and further reducing operating costs and environmental burden. This green and economical treatment method provides crucial technical support for practical engineering applications, demonstrating significant potential, particularly in treating trace amounts of emerging organic micropollutants in wastewater. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the SRUSB reactor and a schematic diagram of the experimental vial of the present invention. Wherein, 1-inlet tank; 2-inlet pump; 3-reactor body; 4-pH meter; 5-oxidation-reduction potential (ORP) meter; 6-internal circulation pump; 7-main unit; 8-sampling valve; 9-outlet pump; 10-outlet tank.

[0045] Figure 2 This is a distribution diagram of PFOS adsorption and degradation in sulfur-mediated sludge.

[0046] Figure 3 This is a distribution diagram of FOSA adsorption and degradation in sulfur-mediated sludge.

[0047] Figure 4 This is a degradation roadmap of PFOS in sulfur-mediated sludge.

[0048] Figure 5 This is a degradation roadmap of FOSA in sulfur-mediated sludge. Detailed Implementation

[0049] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the implementation of the present invention is not limited thereto.

[0050] The wastewater described in this embodiment of the invention is artificially synthesized wastewater, and its main components include PFOS or FOSA, sodium sulfate, various nutrients (Stock stock solution, see Table 1) and trace elements (Trace stock solution, see Table 2).

[0051] Table 1. Components of Nutrient Stock Solution

[0052]

[0053]

[0054] Table 2. Components of Trace Element Stock Solution

[0055]

[0056] Table 3 Influent Water Quality Table

[0057]

[0058] Example 1: Establishment of a stable process environment for the removal of traditional and novel perfluorinated and polyfluoroalkyl compounds from sulfur-mediated sludge.

[0059] (1) Start the reaction apparatus:

[0060] This study employed an upflow sulfate-reducing anaerobic sludge blanket reactor (SRUSB) to cultivate and acclimate sulfur-mediated sludge, laying the foundation for subsequent degradation of perfluorinated and polyfluoroalkyl substances (PFAS). In the first stage of the experiment, 400 mL of sulfate-reducing bacteria (SRB) activated sludge-water mixture with an initial sludge concentration of 15–18 g MLSS / L was added to the reactor. Simultaneously, 20 L of synthetic wastewater was continuously injected into the reactor at a controlled flow rate using a peristaltic pump to acclimate the microorganisms. The synthetic wastewater contained carbon, nitrogen, phosphorus, sulfur, and trace elements. The carbon source was provided by sodium acetate, with an initial COD concentration of 500 mg / L; the sulfur source was provided by sodium sulfate, with sulfate sulfur (SO4) content... 2- The initial concentration of -S) is approximately 270–280 mg / L; the phosphorus source is provided by dipotassium hydrogen phosphate and potassium dihydrogen phosphate, P-HPO4 2- and H2PO4 - The initial concentration was 3–5 mg / L; the nitrogen source was provided by ammonium chloride, and ammonia nitrogen (N-NH4) was used. + The initial concentration of sulfate (SO4) was 15–20 mg / L. During the experiment, the reactor operating conditions were adjusted, including an influent flow rate of 10 L / d, an internal circulation flow rate of 5 times the influent flow rate (5Q), a hydraulic retention time (HRT) of 10 hours, a reaction temperature of 20–35℃, and an influent pH of 6.8–7.5, to ensure thorough mixing of sludge and wastewater and maintain a stable anaerobic environment. The main objective of this stage was to acclimate the microorganisms through sulfate reduction, improve their adaptability to sulfate and metabolic activity, and simultaneously construct a stable sulfur cycle system. No new organic pollutants were added during this process to avoid interfering with the activity of the microbial community. After approximately 1.5 to 2 months of operation, the sulfate (SO4) concentration in the reactor decreased. 2- The removal rate of sulfur dioxide (SFC) reached 90%, and the COD removal rate reached 95%, indicating that the sulfur-mediated sludge has formed a high sulfate reduction capacity and stable metabolic performance. This stage laid a solid foundation for subsequent degradation experiments of perfluorinated and polyfluoroalkyl compounds, and at the same time demonstrated the excellent performance of sulfur-mediated sludge in the removal of traditional pollutants.

[0061] (2) Microbial enhancement for the removal of emerging organic micropollutants based on SRB activated sludge:

[0062] When sulfate (SO4) in the reactor 2-When the removal rate of sulfur dioxide (SOD) reaches 90% and the removal rate of chemical oxygen demand (COD) reaches 95%, it indicates that the sulfur-mediated sludge has completed its initial acclimatization and possesses a high sulfate reduction capacity. At this point, a portion of the mature sulfur-mediated sludge was taken from the mother reactor and evenly distributed into 13 200mL vials. For further experiments, conventional perfluorinated pollutants (PFOS) were added to 6 vials (Group A); novel perfluorinated pollutants (FOSA) were added to another 6 vials (Group B); and the remaining vial, without any perfluorinated or polyfluoroalkyl compounds, served as a blank control group. The initial water formulation of each vial was kept consistent with that of the mother reactor to ensure comparability and consistency of experimental conditions. In the second stage of the experiment, these anaerobic sulfate-reducing sludge were further acclimatized to study their degradation capacity in an environment containing perfluorinated and polyfluoroalkyl compounds. The experiment lasted for 1 to 2 months, and the influent contained carbon sources, sulfur sources, phosphorus sources, nitrogen sources, trace elements, and pollutants such as PFOS or FOSA. To avoid the inhibitory effect of high concentrations of perfluorinated and polyfluoroalkyl compounds (PFOAs) on microbial activity, the initial influent concentration of PFOS or FOSA was set at 100 μg / L, and the mass ratio of carbon, nitrogen, and phosphorus was strictly controlled at 100:10:1 to provide a suitable nutrient ratio and promote microbial growth and metabolism. During this stage, the microorganisms utilized carbon sources and organic pollutants through sulfate reduction, while gradually adapting to and degrading PFOAs. Throughout the experiment, reactor conditions were continuously operated and optimized, and key parameters such as sulfate removal rate, COD removal rate, degradation of PFOAs and PFOAs, and microbial activity were monitored regularly to evaluate the acclimation effect.

[0063] In this embodiment, the sulfate-reducing bacteria (SRB) sludge used was taken from the secondary sedimentation tank of a sewage treatment plant in Hong Kong, China. Unlike other regions, Hong Kong widely uses seawater for toilet flushing, resulting in a significantly higher sulfate concentration in domestic sewage compared to typical urban wastewater. This unique condition provides a favorable environment for the growth and reproduction of sulfate-reducing bacteria, enriching the sludge with SRB and providing a high-quality microbial foundation for the experiment. Initially, the collected sludge was yellowish-brown and had a loose, cotton-like appearance. The ratio of volatile suspended solids (MLVSS) to total suspended solids (MLSS) was 0.51, indicating a low proportion of active microorganisms in the sludge, requiring further enrichment culture to increase their activity and the number of SRBs. Therefore, the initial sludge underwent a one-month enrichment culture. By adjusting culture conditions (such as sulfate concentration, carbon source ratio, and pH range), the proliferation and metabolic activity of SRBs were gradually promoted. During the enrichment culture, as SRBs gradually proliferated, the sludge color changed from yellowish-brown to black, and the morphology changed from loose cotton-like to a more compact flocculent structure. Meanwhile, the MLVSS / MLSS ratio of the sludge significantly increased to 0.80, indicating a substantial increase in the proportion of active microorganisms in the sludge and good enrichment effect of SRB. At this stage, the sludge exhibited high activity and strong stability, meeting favorable application conditions. Therefore, the sludge from this stage was used as inoculum for an upflow sulfate reduction anaerobic sludge bed reactor (SRUSB) for subsequent experiments.

[0064] In this embodiment, the upflow sulfate reduction anaerobic sludge blanket reactor (SRUSB) is the core treatment unit for sludge cultivation in this process. For example... Figure 1As shown, the reactor body is made of plexiglass and consists of an inlet / outlet water system, a reaction zone, and an internal circulation system. The main components of the reactor include sampling valves and piping, inlet / outlet water tanks, inlet / outlet water pumps, an internal circulation pump and piping, an inlet valve, an oxidation-reduction potential (ORP) meter and pH probe and their main unit, and the reactor body itself. The structure is ingeniously designed with an inner diameter of 90 mm, a total height of 600 mm, and an effective volume of 1.5 L to ensure good reaction performance and operational stability. To ensure the stability of the inlet water quality, artificially simulated wastewater was used in the experiment, with fresh water added daily. The wastewater was delivered to the reactor via a peristaltic pump to ensure full contact and reaction with the sulfur-mediated sludge. The reactor effluent was discharged from the top outlet pipe via overflow to maintain a stable liquid level and operating conditions. To further improve the mixing effect of sulfate-reducing bacteria (SRB) activated sludge with wastewater and enhance mass transfer efficiency, an internal circulation system was specifically designed for the reactor. A portion of the effluent is returned to the reactor via an internal circulation pump, creating a circulating flow that enhances the contact reaction between sludge and wastewater. Furthermore, to monitor the reactor's operation in real time, the device is equipped with online oxidation-reduction potential (ORP) and pH monitoring instruments to ensure that reaction conditions remain within a suitable range, providing precise operational assurance for the sulfate reduction process. In the perfluorinated and polyfluoroalkyl compounds (PFAS) degradation experiment, the experimental vials, as a key unit of this process, undertook the main task of studying PFAS degradation. The experimental vials are made of polypropylene, have a capacity of 200 mL, and possess good chemical stability and sealing performance. During the acclimation and cultivation phase, to ensure the stability of the influent water quality, artificially simulated wastewater was used, with fresh water added daily. The vials were placed in a water bath, with the water temperature strictly controlled between 20-35℃ to provide a suitable reaction environment, ensuring the activity of microorganisms and degradation efficiency. Through the above design, the SRUSB reactor and experimental vials each played a crucial role in sludge cultivation and the degradation of per- and polyfluoroalkyl compounds (PFACs). This ensured the efficient acclimatization of sulfate-reducing bacteria and provided a reliable experimental platform for the study of PFAC degradation. This design not only focused on optimizing mass transfer efficiency and reaction conditions but also considered the stability and controllability of the experiment, laying a solid foundation for the successful implementation of this process.

[0065] Example 2: Removal mechanism of traditional and novel perfluorinated and polyfluoroalkyl compounds by sulfur-mediated sludge

[0066] This study proposes a method for treating wastewater containing traditional perfluorinated and polyfluorinated alkyl compounds (PFOS) and novel perfluorinated and polyfluorinated alkyl compounds (FOSA) using sulfur-mediated sludge. This example explores the mechanism of action of sulfur-mediated sludge in treating wastewater containing PFOS and FOSA. Based on the stable process environment established in Example 1, the following experiments were conducted under two conditions: a group with periodically supplemented carbon and sulfur sources (hereinafter referred to as the "supplemented group") and a group without supplemented carbon and sulfur sources (hereinafter referred to as the "non-supplemented group"). The degradation effects of PFOS and FOSA were compared and analyzed.

[0067] (1) The sulfur-mediated sludge, after a period of acclimatization, underwent a water exchange operation. The water exchange formula was consistent with the reactor influent formula to ensure the continuity and comparability of experimental conditions. Subsequently, the sludge was divided into two experimental systems to conduct degradation experiments on different perfluorinated and polyfluoroalkyl compounds (PFOS and FOSA). The specific operation was as follows: In Group A (PFOS experimental group), the PFOS concentration in the influent of 6 vials was increased to 10 mg / L to study the degradation ability of sulfur-mediated sludge under high concentration PFOS environment; in Group B (FOSA experimental group), the FOSA concentration in the influent of 6 vials was also increased to 10 mg / L to explore the degradation effect of sulfur-mediated sludge on the novel perfluorinated and polyfluoroalkyl compound FOSA. The remaining vial did not contain any perfluorinated or polyfluoroalkyl compounds and served as a blank control group. The experiment was run for about 150 days to achieve the degradation experiment of perfluorinated and polyfluoroalkyl compounds in the sludge in the vials.

[0068] (2) Adjust the pH of each reaction system to 7.0; aerate with N2 for 5 minutes to remove air from each reaction system and control each system in an anaerobic environment; tighten the cap and wrap the PP vial with aluminum foil to prevent light from degrading PFOS and FOSA;

[0069] (3) At room temperature of 25℃, in order to make the mud and water in each reactor mix better, each bottle is placed in a constant temperature water bath and the water bath is shaken to ensure that each reaction system is mixed evenly, with a rotation speed of 120 rpm.

[0070] (4) The sampling times for the experimental vials were 0, 2, 5, 8, 13, 18, 27, 52, 70, 82, 100 and 150 days. Each time, 2 ml of mud-water mixture was taken and centrifuged at 7500 rpm in a 4°C centrifuge. The supernatant was taken and filtered into a 2 mL sample vial using a 0.22 μm PTFE filter. The sample was stored in a cold storage at 4°C and the changes in the concentrations of PFOS and FOSA in the aqueous phase were detected and analyzed by LC-MS-MS on the same day.

[0071] (5) In the later stages of the experiment, to further investigate the effect of nutrient conditions on the sulfur-mediated degradation of perfluorinated and polyfluoroalkyl compounds by sludge, different nutrient supplementation strategies were implemented for the vials in groups A and B. Specifically, the nutrient-supplemented groups (3 vials each in groups A and B) were supplemented with carbon, nitrogen, and sulfur sources every 15 days and adjusted to the same nutrient level as the influent water to meet the metabolic needs of the microorganisms; the non-supplemented groups (the other 3 vials) were not supplemented with any carbon, nitrogen, or sulfur sources to simulate the sulfur-mediated degradation behavior of sludge under nutrient-deficient conditions, focusing on whether the sludge would enhance its degradation capacity of perfluorinated and polyfluoroalkyl compounds through its own metabolism or other mechanisms without the supplementation of exogenous nutrients.

[0072] Experimental results are as follows Figure 2 and Figure 3 As shown, Figure 2 In this context, "PFOS-1" and "PFOS-2" represent "PFOS supplement group" and "PFOS non-supplement group," respectively. Figure 3 In this context, "FOSA-1" and "FOSA-2" represent "FOSA Supplementary Group" and "FOSA Non-Supplementary Group," respectively.

[0073] Figure 2 This study examines the adsorption and biodegradation changes of PFOS in sulfur-mediated sludge. In group A, where PFOS was added, the PFOS removal rate reached approximately 45.5% on day 20, increased to 50.1% on day 50, and finally achieved almost complete degradation of 99.5% on day 150. This indicates that sulfur-mediated sludge has a certain degradation capacity in the early stages, and this capacity continuously increases with the extension of operating time. In the non-added group, the PFOS removal rate was 38% on day 20, slightly lower than that of the added group, but significantly increased to 64% on day 50, and finally reached 99.6% on day 150, close to that of the added group. However, the overall degradation effect was consistently better than that of the added group, suggesting that the sludge may degrade PFOS more efficiently through its own metabolism or other mechanisms.

[0074] Figure 3This study examines the adsorption and biodegradation changes of FOSA in sulfur-mediated sludge. In group B, which included FOSA, the removal rate of FOSA increased over time in both groups. However, the degradation effect of the non-supplemented group was significantly better than that of the supplemented group, especially in the early stages. The FOSA removal rate in the supplemented group reached 62.2% on day 20, increased to 72.1% on day 50, and finally reached 99.9% on day 150. In contrast, the FOSA removal rate in the non-supplemented group was already as high as 80.6% on day 20, further increased to 97.5% on day 50, and was completely degraded (100%) on day 150. Overall, the degradation efficiency of FOSA was significantly higher than that of PFOS, and the non-supplemented group showed higher degradation efficiency throughout the entire operation. The removal patterns of the two groups were similar, but the degradation effect of FOSA was superior.

[0075] Depend on Figure 2 and Figure 3 Data on the adsorption of PFOS and FOSA in sludge show that the adsorption rate of PFAS in sulfur-mediated sludge is less than 20%, and degradation is the main pathway.

[0076] Figure 4 and Figure 5 These are the degradation pathways of PFOS and FOSA in a sulfur-mediated system, respectively. PFOS mainly degrades through the removal of CF2 and SO3. - FOSA gradually degrades from long chains to short chains by removing NH, CF2, and SO3. - The reaction gradually degrades long chains into short chains. This is thanks to the synergistic effect of sulfate-reducing bacteria (SRB) and their metabolites, which effectively disrupts the molecular structure of perfluorinated and polyfluoroalkyl compounds PFOS and FOSA, ultimately achieving complete degradation.

[0077] This invention innovatively proposes a method for treating wastewater containing PFOS and FOSA using sulfur-mediated sludge. Through a carefully designed experimental system, it comprehensively reveals the degradation patterns and mechanisms of these two types of perfluorinated and polyfluoroalkyl compounds by sludge under conditions of supplemented carbon and sulfur sources and without supplementation. The results show that sulfur-mediated sludge not only exhibits strong degradation capabilities under high concentrations of perfluorinated and polyfluoroalkyl compounds, but also achieves efficient degradation through its own metabolism or other mechanisms even without external nutrient supplementation. It demonstrates superior degradation performance, particularly in the non-supplemented group, fully showcasing its adaptability and potential application value under resource-limited conditions. Furthermore, this invention systematically analyzes the degradation pathways of PFOS and FOSA, clarifying that degradation mainly occurs through the removal of CF2 and SO3. -The conversion of long-chain to short-chain compounds using groups such as NH provides important theoretical basis and technical support for the treatment of perfluorinated and polyfluoroalkyl compounds. This research not only expands the application scope of sulfur-mediated sludge but also provides a green and sustainable solution for the efficient treatment of perfluorinated and polyfluoroalkyl compound wastewater, possessing significant scientific importance and practical application value.

Claims

1. A method for treating wastewater containing perfluorinated and polyfluoroalkyl compounds using sulfur-mediated sludge, wherein the perfluorinated and polyfluoroalkyl compounds include conventional perfluorinated and polyfluoroalkyl compounds PFOS or novel perfluorinated and polyfluoroalkyl compounds FOSA, characterized in that, Includes the following steps: (1) Cultivation of sulfur-mediated sludge: Sulfate-reducing bacteria activated sludge was inoculated into an upflow sulfate-reducing anaerobic sludge bed reactor and operated in the following mode: influent, anaerobic, reduction, and effluent; artificially synthesized wastewater was introduced into the reactor, which contained carbon source, nitrogen source, sulfur source, phosphorus source and trace elements. During this period, the composition of the influent was precisely controlled to ensure that the mass concentration ratio of carbon, nitrogen and phosphorus was always maintained in the range of 98~100:8~10:0.8~1. (2) Start the first stage: after completing step (1), when the sulfate SO4 2- When the removal rate of sulfate reaches 90% and the removal rate of chemical oxygen demand COD reaches 95%, part of the matured sulfur-mediated sludge in the reactor is taken out into a small vial, PFOS or FOSA is added to the small vial, and the concentration of the added PFOS or FOSA is 0.95-1 mg / L; the operation conditions and water distribution conditions are completely the same as those in the sludge cultivation stage of step (1), and the small vial is operated for 30-40 days according to the mode described in step (1), during which the effluent indexes are regularly monitored, including the removal rate of sulfate, the removal rate of COD, the degradation of perfluoro and polyfluoroalkyl compounds, and the microbial activity, so as to evaluate the effect of domestication and cultivation. (3) Start the second stage: Based on step (2), further increase the concentration of PFOS or FOSA in the vial to 9.5~10 mg / L; its operating conditions and water distribution conditions are exactly the same as those of the sludge cultivation stage in step (1). Operate in the mode described in step (1) for 145~165 days. During this period, monitor the effluent indicators regularly, including sulfate removal rate, COD removal rate, degradation of perfluorinated and polyfluoroalkyl compounds and microbial activity, until the removal rate of perfluorinated and polyfluoroalkyl compounds remains stable.

2. The method according to claim 1, characterized in that, In step (1), the sulfate-reducing bacteria activated sludge is sludge containing abundant sulfate-reducing bacteria.

3. The method according to claim 1, characterized in that, In steps (1) to (3), the mode operation includes water intake, anaerobic digestion, reduction and drainage. During the entire operation, the temperature is maintained at 35-37℃ and the pH is maintained at 6.8-7.

5.

4. The method according to claim 1, characterized in that, In steps (1) to (3), the carbon source in the artificially synthesized wastewater is provided by glucose and sodium acetate, the sulfur source is anhydrous sodium sulfate, the phosphorus source is provided by K2HPO4 and KH2PO4, and the nitrogen source is NH4Cl.

5. The method according to claim 1, characterized in that, The initial concentration of sulfur source was 270~280 mg / L, the initial concentration of COD was 490~510 mg / L, the initial concentration of phosphorus source was 3~5 mg / L, and the initial concentration of nitrogen source was 15~20 mg / L. The pH of the wastewater was adjusted to 6.8~7.5 using hydrochloric acid and sodium hydroxide solution.

6. The method according to claim 1, characterized in that, In steps (1) to (3), the trace elements are added by adding a trace element reserve solution. The trace element reserve solution is prepared by adding trace elements to tap water. The volume ratio of trace elements to tap water is 1 mL / L. The trace element components and their contents are ZnSO4 0.12-0.13 g / L, MnCl2·4H2O 0.12-0.13 g / L, and (NH4)6Mo7O 24 ·4H2O 0.07-0.09 g / L, CuSO4·5H2O 0.03-0.05 g / L, CoCl2·6H2O 0.15-0.16 g / L, NiCl2 0.10-0.12 g / L, EDTA 0.06-0.08 g / L, KI 0.18-0.20g / L and H3BO3 0.10-0.11 g / L.

7. The method according to claim 1, characterized in that, In step (1), the upflow sulfate reduction anaerobic sludge bed reactor is made of plexiglass. The reactor consists of an inlet and outlet water system, a reaction zone and an internal circulation system, and adopts a bottom inlet and overflow outlet design. The reactor components include sampling valves and pipes, inlet and outlet water tanks, inlet and outlet water pumps, internal circulation pumps and pipes, inlet water valves, oxidation-reduction potential (ORP) and pH probes and their main units, as well as the reactor body.

8. The method according to claim 1, characterized in that, In step (1), the concentration of sulfate-reducing bacteria activated sludge is 15-18 g MLSS / L, the ratio of volatile suspended solids to suspended solids in the sludge is 85-90 MLVSS / MLSS, the ratio of COD to sulfate in the wastewater is 1.6-1.8, and the pH of the reaction system is adjusted by adding dilute hydrochloric acid or sodium hydroxide solution and controlled within the range of 6.8-7.

5.

9. The method according to claim 1, characterized in that, The experimental vials used in steps (2) and (3) are made of polypropylene.

10. The method according to any one of claims 1-9, characterized in that, Using the above method to treat wastewater containing traditional perfluorinated and polyfluoroalkyl compounds (PFOS), the PFOS removal rate reached 99.6%; using the above method to treat wastewater containing novel perfluorinated and polyfluoroalkyl compounds (FOSA), the FOSA removal rate reached 100%.

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