Method for simultaneous biodegradation of ammonia nitrogen and perchlorate based on perchlorate-type anaerobic ammonia oxidation reaction

Abstract

This invention belongs to the field of wastewater biological treatment technology, and relates to a method for the simultaneous biodegradation of ammonia nitrogen and perchlorate based on a perchlorate-type anaerobic ammonia oxidation reaction, comprising the following steps: inoculating a mature anaerobic ammonia oxidation granular sludge into an upflow anaerobic reactor, and pumping in artificially synthesized NH4-containing sludge in a continuous influent manner. + and ClO4 ‑ The wastewater has an N / Cl ratio set at 4:3. The reactor operates in a light-protected and anaerobic environment, with its operation cycle divided into three stages: Stage I, Stage II, and Stage III. A gradient increase in substrate loading is employed, and the transition from nitrite-type anaerobic ammonium oxidation to perchlorate-type anaerobic ammonium oxidation is achieved by gradually adjusting the influent concentration during the three stages. This invention uses nitrite-type anaerobic ammonium oxidation sludge as inoculum and NH4+ as the substrate. + ClO4 acts as an electron donor. ‑ Using electron acceptors, the perchlorate-type anaerobic ammonium oxidation reaction was successfully initiated by gradually increasing the influent substrate concentration, thereby achieving NH4+ oxidation. + and ClO4 ‑ Synchronous removal.

Description

Technical Field

[0001] This invention belongs to the field of wastewater biological treatment technology, specifically relating to a method for the simultaneous biodegradation of ammonia nitrogen and perchlorate based on a perchlorate-type anaerobic ammonia oxidation reaction. Background Technology

[0002] Ammonium perchlorate (NH4ClO4) is a strong oxidizing agent with advantages such as high oxygen content, high density, and low cost, and is widely used in aerospace engineering and military manufacturing industries. Ammonium perchlorate is very stable in physicochemical properties, existing stably in nature for over ten years. When dissolved in water, it typically dissociates into NH4+. + and ClO4 - Two ionic forms, thus causing NH4 in water to... + and ClO4 - The problem of co-contamination. With the increasing discharge of industrial wastewater containing ammonium perchlorate, NH4+ is causing increasingly serious pollution in the environment. + and ClO4 - Co-contamination issues. Among them, excessive NH4. + It can cause eutrophication of water bodies and affect the ecological balance; ClO4 - It can enter the human body through the food chain, interfering with the thyroid gland's normal uptake of iodine, hindering normal metabolism, and causing public health problems. Currently, the treatment method for this type of wastewater is usually a step-by-step process involving NH4. + and ClO4 - The separate removal of NH4 + and ClO4 - There are relatively few research reports on simultaneous removal.

[0003] Removing NH4 by the growth and metabolism of microorganisms + and ClO4 - It is recognized as the most economical and effective treatment method. Among them, anaerobic ammonia oxidation (Anammox) is a novel, low-consumption, and clean method in the field of biological nitrogen removal, namely: anaerobic ammonia-oxidizing bacteria (AnAOB) oxidize nitrogen under anaerobic conditions using NO2... - As an electron acceptor, it directly accepts NH4 + Oxidized to N2 and a small amount of NO3 - Compared to traditional nitrification-denitrification nitrogen removal processes, Anammox offers advantages such as requiring no external carbon source, no nutrient supply, no alkalinity adjustment, and producing less sludge. Although Anammox is significant for global nitrogen cycling and biological nitrogen removal from wastewater, its application and development are currently hampered by the electron acceptor NO2. - Supply shortages.

[0004] In recent years, researchers have discovered that AnAOB has diverse metabolic pathways, in addition to metabolizing NO2. - In addition to acting as an electron acceptor, it can also couple with different electron acceptors (SO4). 2- Fe 3+ Mn 4+ As 5+ The reduction of ClO4. From a thermodynamic perspective, ClO4 - redox potential E 0 It is 1.287V, compared to NO2. - Its redox potential is high at 0.43V, therefore, NH4 + and ClO4 - There is a larger potential difference between them, so theoretically it can also become NH4. + Electron acceptor for anaerobic oxidation.

[0005] Based on this, the present invention uses nitrite anammox sludge as inoculum and NH4+ as the inoculum. + ClO4 acts as an electron donor. - Using an electron acceptor, the perchlorate-type anaerobic ammonium oxidation reaction was successfully initiated by gradually increasing the influent substrate concentration, thus realizing NH4 under anaerobic conditions. + and ClO4 - Synchronous removal. Summary of the Invention

[0006] This invention addresses the problem of ammonia nitrogen and perchlorate (NH4) levels caused by the excessive use and improper handling of ammonium perchlorate in existing technologies. + and ClO4 - To address the co-polluting problem, a method for the simultaneous biodegradation of ammonia nitrogen and perchlorate based on perchlorate-type anaerobic ammonia oxidation is proposed. This method involves inoculating an upflow anaerobic reactor with anaerobic ammonia oxidation granular sludge, using ClO4... - Replace NO2 - Using NH4+ as the sole electron acceptor, it successfully achieved NH4+ over 100 days under inorganic anaerobic conditions. + and ClO4 - Remove synchronously.

[0007] The technical solution of this invention is:

[0008] A method for simultaneous biodegradation of ammonia nitrogen and perchlorate based on perchlorate-type anaerobic ammonia oxidation reaction includes the following steps:

[0009] Mature anaerobic ammonium oxidation granular sludge was inoculated into an upflow anaerobic reactor, and artificially synthesized NH4-containing sludge was pumped in via continuous influent. + and ClO4 -The wastewater has an N / Cl ratio set at 4:3. The reactor operates in a light-proof and anaerobic environment, and its operation cycle is divided into three stages: Stage I, Stage II, and Stage III. The substrate load is increased in a gradient manner. During the operation of the three stages, the influent concentration is gradually adjusted to achieve the transformation from nitrite-type anaerobic ammonia oxidation to perchlorate-type anaerobic ammonia oxidation.

[0010] Furthermore, the reactor operates for a total of 100 days, with the first stage lasting from 0 to 29 days. This stage is the start-up stage, during which the influent NH4+ is used. + and ClO4 - The concentrations were set at 4 mM and 3 mM, respectively.

[0011] Phase II lasts 30–65 days, NH4 + The load increased from 4 mM in stage I to 8 mM, ClO4 - The load increased accordingly from 3mM in Phase I to 6mM;

[0012] Phase III lasts 66–100 days, NH4 + The load was increased to 12 mM, ClO4 - The load was increased accordingly to 9mM.

[0013] Furthermore, the initial influent to the reactor contains NH4 at concentrations of 4 mM and 3 mM, respectively. + and ClO4 - It also contains 0.03 g / L KH2PO4, 0.3 g / L MgSO4·7H2O, 1.0 g / L NaHCO3, 0.14 g / L CaCl2·2H2O, 1 mL / L trace element I and 1 mL / L trace element II; the initial pH of the influent is 8.00±0.30.

[0014] Furthermore, the components of trace element I are 5 g / L EDTA and 5 g / L FeSO4·7H2O, and the components of trace element II are 0.1 g / L ZnSO4·7H2O, 0.05 g / L MnSO4·H2O, 0.05 g / L H3BO3, 0.2 g / L CoCl2·6H2O, 0.01 g / L CuSO4·5H2O, 0.02 g / L NiCl2·6H2O, and 0.03 g / L Na2MoO4·2H2O.

[0015] Furthermore, the reactor inlet is controlled by adjusting the speed of the peristaltic pump. The reactor inlet is connected to an inlet bottle, and high-purity nitrogen gas is continuously introduced into the inlet bottle to ensure a sufficient anaerobic environment. The reactor outlet overflows from the outlet at the top of the reactor.

[0016] Furthermore, the amount of inoculated mud is 40% of the reactor's working volume.

[0017] Furthermore, the reactor is made of high borosilicate glass, with a diameter of 9 cm, a height of 20 cm, and an effective volume of 1 L.

[0018] The beneficial effects of this invention are:

[0019] The method for simultaneous biodegradation of ammonia nitrogen and perchlorate proposed in this invention involves inoculating a mature anaerobic ammonia oxidation granular sludge into an upflow anaerobic reactor, and pumping in artificially synthesized NH4-containing sludge via a continuous influent flow. + and ClO4 - The wastewater (with an N / Cl ratio of 4:3) is converted from nitrite-type anaerobic ammonia oxidation to perchlorate-type anaerobic ammonia oxidation by gradually adjusting the influent concentration.

[0020] This invention proposes a novel perchlorate-type anaerobic ammonium oxidation reaction that can utilize NH4+. + ClO4 as an electron donor - Reduced to Cl - Thus, NH4 is achieved under anaerobic conditions. + and ClO4 - Synchronous removal. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the Perammox reactor structure;

[0022] Figure 2 The reactor's response to NH4 at different operating stages + and ClO4 - The removal status; where (a) represents the NH4 removal status of the influent and effluent. + (a) Concentration and removal efficiency; (b) ClO4 in influent and effluent - Concentration and its removal efficiency;

[0023] Figure 3 This is a graph showing the abundance changes of microbial community structure at the genus level during different operational stages. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] To further understand the present invention, it will be further described in conjunction with the accompanying drawings and embodiments.

[0026] Example 1

[0027] This invention provides a simultaneous biodegradation of ammonia nitrogen (NH4) based on perchlorate-type anaerobic ammonia oxidation reaction. + ) and perchlorate (ClO4) - The method, in such Figure 1 The experiment was conducted in the Perammox reactor shown. This reactor is an upflow anaerobic reactor made of borosilicate glass, with a diameter of 9 cm, a height of 20 cm, and an effective volume of 1 L.

[0028] Mature anaerobic ammonium oxidation granular sludge was inoculated into an upflow anaerobic reactor. The reactor influent was synthetic wastewater, with NH4 as the main substrate. + and ClO4 - NH4 + Provided by NH4Cl, ClO4 - Provided by NaClO4.

[0029] The reactor influent is controlled by adjusting the speed of the peristaltic pump, while the effluent overflows from the outlet at the top of the reactor. To ensure an anaerobic environment, the synthetic wastewater is first purged with high-purity nitrogen (99.999%) for 10 minutes to remove oxygen. Then, high-purity nitrogen is continuously introduced into the influent bottle to ensure a sufficient anaerobic environment. The nitrogen flow rate is controlled by a glass rotor flow meter. The reactor is wrapped with black tarpaulin to prevent light from affecting the microorganisms and is placed in a constant-temperature water bath to maintain the temperature at approximately 30°C.

[0030] The inoculated sludge in the reactor was acclimated over a long period of time in a laboratory upflow anaerobic sludge blanket reactor (UASB) with NO2. - The mature anaerobic ammonia oxidation granular sludge, which is an electron acceptor, is brick red in color. The inoculum amount is 40% of the reactor's working volume.

[0031] The reactor employs a gradient-increasing substrate loading method to achieve the transition from nitrite-type anaerobic ammonium oxidation to perchlorate-type anaerobic ammonium oxidation. The initial influent to the reactor contains NH4. + and ClO4 -The concentrations were 4 mM and 3 mM. The remaining components included 0.03 g / L KH2PO4, 0.3 g / L MgSO4·7H2O, 1.0 g / L NaHCO3, 0.14 g / L CaCl2·2H2O, 1 mL / L trace element I and 1 mL / L trace element II. Finally, the pH was adjusted to 8.00±0.30 with NaOH. The components of trace element I are 5 g / L LEDTA and 5 g / L FeSO4·7H2O, while trace element II includes 0.1 g / L ZnSO4·7H2O, 0.05 g / L MnSO4·H2O, 0.05 g / L H3BO3, 0.2 g / L CoCl2·6H2O, 0.01 g / L CuSO4·5H2O, 0.02 g / L NiCl2·6H2O, and 0.03 g / L Na2MoO4·2H2O.

[0032] The entire operation period is divided into three stages, with the N / Cl ratio set at 4:3, the hydraulic retention time (HRT) fixed at 25 hours, and NH4+... + The load increased from 4 mM in stage I to 8 mM in stage II and 12 mM in stage III, respectively, ClO4 - The load increased accordingly from 3 mM in stage I to 6 mM in stage II and 9 mM in stage III. During the experiment, influent and effluent water samples were collected every 24 hours to measure NH4. + and ClO4 - The concentration was determined, and the simultaneous removal was analyzed.

[0033] In this specific embodiment, the reactor operated for a total of 100 days, divided into three phases: Phase I (days 0-29), Phase II (days 30-65), and Phase III (days 66-100). The reactor simultaneously removed NH4 during each of the different phases. + and ClO4 - The situation is as follows Figure 2 As shown.

[0034] Phase I (0-29 days): Influent NH4 during the start-up phase + and ClO4 - The concentrations were set at 4 mM and 3 mM, respectively. Days 0–10 were the acclimatization period for the anaerobic ammonia oxidation granular sludge. NH4 + First, a transformation occurs, producing NH4 in the effluent. + The concentration gradually decreased from 1.86±0.07 mM to 1.28±0.02 mM, and the removal rate increased from 55.26±0.79% to 66.79±0.51%. Figure 2 a) and the effluent ClO4 - The concentration remained higher than that of the influent, and no conversion occurred. Figure 2b). Subsequently, from day 11 to day 29, the microorganisms in the sludge adapted to the environment, and the activity of functional microorganisms began to increase, ClO4 - With NH4 + Synchronous conversion begins. At this time, NH4 + The average effluent concentration was 0.83 ± 0.23 mM, and the average removal rate was 79.48 ± 5.83%. Figure 2 a). And ClO4 - The average effluent concentration was 2.53 ± 0.14 mM, and the average removal rate was 17.83 ± 5.18%. Figure 2 b).

[0035] Phase II (30-65 days): Maintain HRT unchanged, increase influent NH4 + and ClO4 - The concentrations were increased to 8 mM and 6 mM, respectively. During this stage, NH4... + The removal of NH4 is basically stable. + The average effluent concentration was 3.46 ± 0.75 mM, and the average removal rate was 56.44 ± 9.26%. Figure 2 a). And ClO4 - The average effluent concentration was 5.19 ± 0.32 mM, and the average removal rate was 13.89 ± 4.65%. Figure 2 b).

[0036] Phase III (66-100 days): To further improve NH4 + and ClO4 - The removal efficiency continues to reduce the influent NH4. + and ClO4 - The concentrations were increased to 12 mM and 9 mM. Figure 2 The display shows that NH4 + The removal efficiency of ClO4 gradually decreases. - The removal rate of NH4 changed relatively little. + The average removal rate gradually decreased from 56.44±9.26% to 29.56±5.23%. Figure 2 a). When ClO4 is introduced into the water - After the concentration was increased, the average effluent ClO4 - The concentration was 7.50 ± 0.65 mM, and the average removal rate was 16.95 ± 7.55%. Figure 2 b).

[0037] This demonstrates that using traditional nitrite-type anaerobic ammonium oxidation sludge as the sludge source successfully initiated a perchlorate-type anaerobic ammonium oxidation reaction, achieving NH4 under inorganic anaerobic conditions. + and ClO4 - Simultaneous removal. When influent NH4 +and ClO4 - At concentrations of 4 mM and 3 mM, NH4 + and ClO4 - The average removal rates were the highest, at 79.48±5.83% and 17.83±5.18%, respectively.

[0038] Experimental Example 1

[0039] High-throughput sequencing analysis was performed on the sludge from the reactor on days 29, 65, and 100 of operation. Microbial groups with a relative abundance of >1% (groups with a relative abundance of <1% were merged into "Others") were statistically analyzed at the genus level to obtain a graph showing the changes in microbial community abundance during reactor operation.

[0040] like Figure 3 As shown, on days 29, 65, and 100 of reactor operation, the relative abundance of the anaerobic ammonia-oxidizing bacterium Candidatus_Kuenenia decreased from 51.61% to 41.04% and 20.86%, respectively, but it remained the dominant genus, and its decreasing trend was consistent with that of NH4+. + The removal rate trends were consistent, indicating that this genus of bacteria may have a significant effect on the removal of NH4 in the reaction system. + Removal is crucial. Besides Candidatus Kuenenia, the relative abundance of A4b, Truepera, and SBR1031 increased significantly, from 6.74%, 1.42%, and 2.46% on day 29 to 18.53%, 10.02%, and 7.6% on day 100, respectively. A4b and SBR1031 both belong to the Anaerolineae class of the Chloroflexi phylum and are common anaerobic fermenting bacteria in wastewater treatment systems, contributing to improved sludge flocculation performance and related to the formation of granular sludge. Truepera belongs to the Deinococcus-Thermus phylum. This genus is not only important for wastewater denitrification but also resistant to harsh environmental conditions; its increased relative abundance indicates a greater suitability for high NH4 loads. + and ClO4 - Conditions. In addition, bacteria with denitrification functions, such as Limnobacter, Arenimonas, and Thermomonas, were also detected. Their relative abundance remained relatively stable at different operating stages, indicating that the denitrification process significantly impacts NH4+ during reactor operation. + and ClO4 -The removal of NH4+ played a relatively minor role. The relative abundance of nitrifying bacteria NB1-j did not change significantly, accounting for approximately 2% of the total bacterial abundance, suggesting that this genus was a symbiotic functional bacterium initially inoculated into the anaerobic ammonia oxidation granular sludge. Theoretically, nitrifying bacteria can consume oxygen and remove NH4+ even under oxygen interference. + Converted to NO2 - Provides NO2 for nitrite-type anaerobic ammonium oxidation reaction. - The substrate promotes the anaerobic ammonium oxidation of nitrite, thereby inhibiting the perchlorate-type anaerobic ammonium oxidation. This is likely due to the presence of ClO4 in this embodiment. - The reason for the low removal rate is that the relative abundance of Ferruginibacter gradually increased from 0.18% on day 29 to 2.51% on day 100. This genus is an important organic matter degrading bacterium and can couple with NO2. - NO3 - SO4 2- and Fe 3+ The reduction of ClO4 indicates that it has metabolic multifunctionality. Because the organic matter content in the system of this embodiment is extremely low, and ClO4... - Redox properties and NO3 - and SO4 2- Similar to this, it is speculated that this genus of bacteria likely thrives under anaerobic conditions using NH4+. + To achieve electron donation with ClO4 - The coupling of reduction suggests that Ferruginibacter is likely a functional bacterium involved in perchlorate-type anaerobic ammonium oxidation.

[0041] It is noteworthy that on the 100th day of reactor operation, only the typical perchlorate-reducing bacterium *Dechlorosoma*, now renamed *Azospira*, with a relative abundance of 0.01%, was enriched in the system, indicating that ClO4 in the system... - The degradation does not solely depend on the traditional ClO4 - The reduction process further confirmed the occurrence of perchlorate-type anaerobic ammonium oxidation. In summary, using anaerobic ammonium oxidation granular sludge as inoculum and NH4+ as the catalyst... + ClO4 acts as an electron donor. - In a reaction system with the electron acceptor, perchlorate-type anaerobic ammonium oxidation was successfully initiated, thereby realizing ClO4 - and NH4 + Synchronous removal.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, alterations, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for simultaneous biodegradation of ammonia nitrogen and perchlorate based on perchlorate-type anaerobic ammonia oxidation reaction, characterized in that, Includes the following steps: Mature anaerobic ammonium oxidation granular sludge was inoculated into an upflow anaerobic reactor, and artificially synthesized NH4-containing sludge was pumped in via continuous influent. + and ClO4 - The wastewater has an N / Cl ratio set at 4:

3. The reactor operates in a light-proof and anaerobic environment, and its operation cycle is divided into three stages: Stage I, Stage II, and Stage III. The substrate load is increased in a gradient manner. During the operation of the three stages, the influent concentration is gradually adjusted to achieve the transformation from nitrite-type anaerobic ammonia oxidation to perchlorate-type anaerobic ammonia oxidation.

2. The method according to claim 1, characterized in that, The reactor operated for a total of 100 days, with Phase I (days 0-29) being the start-up phase. During this phase, the influent NH4... + With ClO4 - The concentrations were set at 4 mM and 3 mM, respectively. Phase II lasts 30–65 days, NH4 + The load increased from 4 mM in Stage I to 8 mM, ClO4 - The load increased accordingly from 3mM in Phase I to 6mM; Phase III lasts 66–100 days, NH4 + The load was increased to 12 mM, ClO4 - The load was increased accordingly to 9mM.

3. The method according to claim 1, characterized in that, The initial influent to the reactor contained NH4 at concentrations of 4 mM and 3 mM, respectively. + and ClO4 - It also contains 0.03 g / L KH2PO4, 0.3 g / L MgSO4·7H2O, 1.0 g / L NaHCO3, 0.14 g / L CaCl2·2H2O, 1 mL / L trace element I and 1 mL / L trace element II; the initial pH of the influent is 8.00±0.

30.

4. The method according to claim 3, characterized in that, The components of trace element I are 5 g / L EDTA and 5 g / L FeSO4·7H2O, and the components of trace element II are 0.1 g / L ZnSO4·7H2O, 0.05 g / L MnSO4·H2O, 0.05 g / L H3BO3, 0.2 g / L CoCl2·6H2O, 0.01 g / L CuSO4·5H2O, 0.02 g / L NiCl2·6H2O, and 0.03 g / L Na2MoO4·2H2O.

5. The method according to claim 1, characterized in that, The reactor inlet water is controlled by adjusting the speed of the peristaltic pump. The reactor inlet is connected to an inlet bottle, and high-purity nitrogen gas is continuously introduced into the inlet bottle to ensure a sufficient anaerobic environment. The reactor outlet water overflows from the outlet at the top of the reactor.

6. The method according to claim 1, characterized in that, The amount of inoculum should be 40% of the reactor's working volume.

7. The method according to claim 1, characterized in that, The reactor is made of borosilicate glass, with a diameter of 9 cm, a height of 20 cm, and an effective volume of 1 L.

Images