Iron-carbon modified basalt fiber particle electrode biological carrier, preparation method and application thereof

Abstract

This application discloses an iron-carbon modified basalt fiber particle electrode biocarrier, its preparation method, and its application. The preparation method includes the following steps: S a 1. After pretreatment and etching, the basalt fibers are ground and sieved, then immersed in an iron salt solution for 6-12 hours at a temperature of 50-90℃; a 2. Step S a The obtained basalt fibers were soaked in a sodium p-toluenesulfonate solution, followed by the addition of pyrrole monomer and then an iron salt solution. The reaction was carried out at room temperature for 12–24 h. The mass ratio of basalt fibers, sodium p-toluenesulfonate, pyrrole monomer, and ferric iron was 5.0:9.7–10.8:3.4–4.2:5.5–6.6. a 3. The basalt fibers obtained in step S2 are calcined in stages. The iron-carbon modified basalt fiber particle electrode biocarrier of this application has a porosity of 90-93% and a density of 1.03-1.15 g / cm³. 3 Its high porosity and low density make it easy to suspend, which is conducive to the enrichment and growth of microorganisms on the surface. It can achieve the enrichment and cultivation of marine anaerobic ammonia-oxidizing bacteria, thus exhibiting excellent denitrification performance for high-salinity nitrogen-containing wastewater.

Description

Technical Field

[0001] This invention relates to the field of microbial wastewater denitrification technology, and more specifically, to iron-carbon modified basalt fiber particle electrode biocarriers, their preparation methods and applications, and anaerobic denitrification granular sludge reactors, their construction methods and applications. Background Technology

[0002] High-salinity aquaculture wastewater is characterized by high salinity and a low carbon-to-nitrogen ratio. Releasing nitrogen compounds into the marine ecosystem can lead to red tides, which reduce dissolved oxygen and threaten aquatic life. Furthermore, high salinity is harmful to microorganisms, causing cytoplasmic segregation and a sharp increase in osmotic pressure, resulting in the loss of microbial activity. Therefore, developing an efficient biological process for treating saline wastewater is of paramount importance.

[0003] Anaerobic ammonia oxidation shows great promise for the efficient treatment of nitrogen-containing wastewater. As one of the six known genera of anaerobic ammonia-oxidizing bacteria, ... Candidatus Scalindua Belonging to the marine anammox bacteria (MAB), they play a crucial role in the nitrogen cycle of marine ecosystems. Compared to anammox bacteria in low-salinity environments, MABs exhibit better salt tolerance, making them more suitable for treating saline and nitrogenous wastewater. They maintain stable denitrification performance over a wide salt concentration range (5-35 g / L sodium chloride), even demonstrating high denitrification performance at salinity levels as low as 50 g / L. However, anammox bacteria (AnAOB) still have some drawbacks: they grow slowly and are easily affected by environmental factors, making them extremely difficult to cultivate in practical applications. The start-up and stable operation of Anammox have become obstacles to their engineering applications.

[0004] Anaerobic ammonia oxidation granulation technology is a key strategy for reducing sludge loss and ensuring sufficient biomass in the reactor. Granular sludge is favored due to its excellent settling performance, compact structure, and efficient biomass retention capacity. Suspended particles can increase the contact efficiency with pollutants in wastewater, thereby improving degradation effects. Basalt fiber, as an aluminosilicate fiber, possesses properties such as corrosion resistance, good flexibility, resistance to high and low temperatures, and environmental friendliness, making it one of the key new materials being developed in my country. However, it has received relatively little attention in the field of high-salinity wastewater purification. The main reason is its poor surface conductivity and insufficient biocompatibility, which hinders the rapid adhesion and stable attachment of microorganisms, resulting in unsatisfactory biomass fixation performance in wastewater treatment applications.

[0005] In summary, there is currently a lack of modified basalt fiber biocarriers with ideal biomass fixation performance. Summary of the Invention

[0006] To address the problems of weak microbial fixation and limited denitrification efficiency caused by insufficient surface physicochemical properties, water dispersibility, and conductivity of existing basalt fibers, this application aims to improve the biocompatibility and conductivity of basalt fibers, thereby enhancing their treatment efficiency for high-salinity nitrogen-containing wastewater.

[0007] This application modifies basalt fibers using iron and organic polymer carbon materials. This modification increases the surface charge of the basalt fibers, thereby enhancing their adsorption capacity for microorganisms. Furthermore, it improves the electrical conductivity of the basalt fibers. In addition, the reaction between iron and carbon provides electrons to the carrier electrode, promoting microbial growth and metabolism, and increasing the denitrification effect.

[0008] Therefore, the purpose of this application is to develop modified basalt fibers with excellent biocompatibility and good electrical conductivity to meet the characteristic requirements of biological fillers.

[0009] More specifically, in a first aspect, this application provides a method for preparing an iron-carbon modified basalt fiber particle electrode biocarrier, comprising the following steps:

[0010] S a 1. After pretreatment and etching, the basalt fibers are ground and sieved, then soaked in an iron salt solution for 6-12 hours at a temperature of 50-90℃.

[0011] S a 2. Step S a The obtained basalt fibers were soaked in sodium p-toluenesulfonate solution, followed by the addition of pyrrole monomer and then iron salt solution. The reaction was carried out at room temperature for 12-24 h. The mass ratio of basalt fibers, sodium p-toluenesulfonate, pyrrole monomer and ferric iron was 5.0:9.7-10.8:3.4-4.2:5.5-6.6.

[0012] S a 3. The basalt fibers obtained in step S2 are calcined in stages, wherein...

[0013] First stage: Raise the temperature to 180-220°C and maintain the temperature for 25-40 minutes.

[0014] Second stage: Raise the temperature to 350-400°C and maintain the temperature for 80-100 minutes.

[0015] Third stage: Raise the temperature to 510-560°C and keep it warm for 100-130 minutes.

[0016] Preferably, step S a The pretreatment in section 1 includes: immersing basalt fibers in acetone solvent, heating to 38-42℃ and reacting for more than 1 hour, and / or

[0017] Step Sa The etching process in 1 includes: placing basalt fibers in an etching solution and reacting at 20-90°C for 1-24 hours, wherein the etching solution includes one or more of hydrochloric acid solution, sulfuric acid solution, hydrogen peroxide solution and sodium hydroxide solution.

[0018] Preferably, step S a The etching process in section 1 includes: first, placing the basalt fiber in hydrochloric acid solution, sulfuric acid solution, or sodium hydroxide solution and reacting at 20-90℃ for 2-24 hours, and then placing it in hydrogen peroxide solution and reacting at 40-90℃ for 1-12 hours.

[0019] Preferably, step S a Step 3 also includes: step S a The basalt fibers obtained in step 2 were washed and purified with water and ethanol, and then dried at 60-70℃.

[0020] Secondly, this application provides an iron-carbon modified basalt fiber particle electrode biocarrier, which is prepared by the above-mentioned preparation method of the iron-carbon modified basalt fiber particle electrode biocarrier.

[0021] Preferably, the iron-carbon modified basalt fiber particle electrode biocarrier has a porosity of 90-93% and a density of 1.03-1.15 g / cm³. 3 .

[0022] Thirdly, this application provides a method for constructing an anaerobic denitrification granular sludge reactor, comprising the following steps:

[0023] S b 1. Inoculate the pretreated marine sediment into the reactor;

[0024] S b 2. Add the above-mentioned iron-carbon modified basalt fiber particle electrode biocarrier;

[0025] S b 3. Cultivate and acclimate the product for 20-40 days at a temperature of 28-32℃ and a stirring speed of 30-60 rpm. The influent ammonia nitrogen concentration is 100-120 mg / L, nitrite nitrogen concentration is 100-120 mg / L, sodium chloride concentration is 10-35 g / L, pH is 7.0-8.0, and hydraulic retention time is 10-24 hours.

[0026] Fourthly, this application provides an anaerobic denitrification granular sludge reactor, which is constructed using the above-described method for constructing an anaerobic denitrification granular sludge reactor.

[0027] Fifthly, this application provides the application of the above-mentioned iron-carbon modified basalt fiber particle electrode biological carrier or the above-mentioned anaerobic denitrification granular sludge reactor in the treatment of high-salinity nitrogen-containing wastewater, wherein the sodium chloride content in the high-salinity nitrogen-containing wastewater is 10-35 g / L, especially 25-35 g / L.

[0028] Sixthly, this application provides a method for treating high-salinity nitrogen-containing wastewater, comprising passing the high-salinity nitrogen-containing wastewater into the above-mentioned anaerobic denitrification granular sludge reactor, and controlling the temperature inside the reactor to be 28-32℃ and the stirring speed to be 30-60 rpm.

[0029] The technical solution of this application achieves the following technical effects:

[0030] 1. The iron-carbon modified basalt fiber particle electrode biocarrier prepared in this application has a porosity of 90-93% and a density of 1.03-1.15 g / cm³. 3 Its high porosity and low density make it easy to suspend, which is conducive to the enrichment and growth of microorganisms on the surface, and can realize the enrichment and cultivation of marine anaerobic ammonia oxidizing bacteria.

[0031] 2. This application modifies basalt fibers with iron and organic polymer carbon materials, which on the one hand increases the surface charge of basalt fibers, thereby enhancing their adsorption capacity for microorganisms and facilitating the adsorption and enrichment of microorganisms on their surface; on the other hand, it further improves the conductivity of basalt fibers.

[0032] 3. The iron-carbon modified basalt fiber particle electrode biocarrier forms a galvanic cell-like effect through the synergistic interaction of iron oxides (Fe²⁺ / Fe³⁺) and carbon materials, enhancing electron transfer capacity and thus promoting anammox denitrification. The oxidation and reduction of Fe²⁺ forms an iron redox cycle, continuously transferring electrons. The carbon material, acting as a conductive network, integrates the redox activity of iron ions, forming Fe-C composite active sites, synergistically improving electron utilization. The high specific surface area and porous structure of the iron-carbon modified basalt fiber particle electrode biocarrier provide attachment sites for Fe²⁺ / Fe³⁺ and microorganisms, increasing the reaction interface. Simultaneously, the iron-carbon modified basalt fiber particle electrode biocarrier is corrosion-resistant, maintaining the activity of the Fe-C composite structure over a long period.

[0033] 4. The anaerobic denitrification granular sludge reactor constructed using iron-carbon modified basalt fiber granular electrode biological carrier in this application has shown excellent denitrification performance in treating high-salinity nitrogen-containing wastewater (sodium chloride content of 10-35 g / L, especially 25-35 g / L), with ammonia nitrogen removal rate exceeding 93% and nitrite nitrogen removal rate exceeding 91%.

[0034] The following will further explain the concept, specific structure and technical effects of this application in conjunction with the accompanying drawings, so as to fully understand the purpose, features and effects of this application. Attached Figure Description

[0035] Figure 1 This is a SEM image of the basalt fibers after pretreatment and etching in Example 1 of this application.

[0036] Figure 2 This is a SEM image of basalt fibers before calcination after modification with iron and organic polymer carbon materials in Example 1 of this application.

[0037] Figure 3 This is a SEM image of the calcined iron-carbon modified basalt fiber particle electrode biocarrier in Example 1 of this application.

[0038] Figure 4 This is the EDS elemental analysis diagram of the iron-carbon modified basalt fiber particle electrode biocarrier finally obtained in Example 1 of this application.

[0039] Figure 5 This is another EDS elemental analysis diagram of the iron-carbon modified basalt fiber particle electrode biocarrier finally obtained in Example 1 of this application.

[0040] Figure 6 This is the C element XPS diagram of the iron-carbon modified basalt fiber particle electrode biocarrier in Example 1 of this application.

[0041] Figure 7 This is the Fe element XPS image of the iron-carbon modified basalt fiber particle electrode biocarrier in Example 1 of this application.

[0042] Figure 8 This is a schematic diagram of the anaerobic denitrification granular sludge reactor of this application.

[0043] Figure 9 The NH4+ in nitrogen-containing wastewater with different sodium chloride concentrations in Example 9 + -N, NO2 - -N Influent and Effluent Concentration Variation Statistical Chart. Detailed Implementation

[0044] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0045] Some exemplary embodiments of this application have been described for illustrative purposes. It should be understood that this application may be implemented in other ways not specifically shown in the accompanying drawings.

[0046] In a first aspect, this application provides a method for preparing an iron-carbon modified basalt fiber particle electrode biocarrier, comprising the following steps: S a 1. After pretreatment and etching, the basalt fibers are ground and sieved, then iron-modified; S a 2. Step S a The basalt fibers obtained in step 1 were modified with organic polymer carbon materials; S a 3. Calcination is carried out in stages to obtain the final product. Each step is described in detail below.

[0047] Iron modification of basalt fiber

[0048] Before iron modification of basalt fibers, pretreatment and etching are performed. The purpose of pretreatment is to remove the original adhesives and impurities on the surface of the basalt fibers. Specifically, the pretreatment method involves immersing the basalt fibers in acetone solvent and heating to 38-42°C for at least 1 hour. It should be understood that other pretreatment methods can also be used in this application, such as replacing acetone with other solvents (ethanol, etc.). The temperature and reaction time can be selected according to the chosen solvent and other actual conditions, as long as the purpose of removing the original adhesives and impurities on the surface of the basalt fibers can be achieved. After pretreatment, drying is preferred. The drying temperature is not limited in this application, as long as the cleaning solvent is no longer adhering to the surface of the basalt fibers.

[0049] The etching process is performed after pretreatment. The purpose of etching is to increase the surface roughness of the basalt fibers, thereby improving their loading capacity for subsequent modified materials. Specifically, the etching method involves placing the pretreated basalt fibers in an etching solution and reacting them at 20-90℃ for 1-24 hours. The etching solution includes one or more of hydrochloric acid, sulfuric acid, hydrogen peroxide, and sodium hydroxide solutions. This application does not limit the concentration of the etching solution, as long as it can increase the surface roughness of the basalt fibers. When the concentration of the etching solution is low, the etching time can be appropriately increased; when the concentration of the etching solution is high, the etching time can be appropriately reduced. For example, the concentration of the etching solution can be 1M, 1.5M, etc.

[0050] In one specific embodiment, the etching process includes first placing the pretreated basalt fibers in a hydrochloric acid solution, sulfuric acid solution, or sodium hydroxide solution and reacting at 20-90°C for 2-24 hours, followed by reacting in a hydrogen peroxide solution at 40-90°C for 1-12 hours. Treating the basalt fibers with hydrochloric acid, sulfuric acid, or sodium hydroxide solution increases surface defects. Subsequent immersion in hydrogen peroxide increases the Si-O groups on the basalt fiber surface, enabling subsequent organic polymer carbon materials to be loaded onto its surface. The subsequent high-temperature calcination carbonization creates a porous and loose structure, which is conducive to the enrichment and growth of microorganisms.

[0051] It should be understood that other etching methods can also be used in this application, such as using other etching solutions instead. The temperature and reaction time can be selected according to the chosen solution and other actual conditions, as long as the purpose of increasing the surface roughness of the basalt fiber can be achieved. After etching, it is preferable to clean and dry to remove the etching solution. This application does not limit the drying temperature, as long as the cleaning solution is no longer attached to the surface of the basalt fiber.

[0052] Before iron modification, the pretreated and etched basalt fibers are ground and sieved to ensure that the subsequent modified material is loaded more fully. Grinding sieves can be selected from 140 mesh, 170 mesh, 200 mesh, 230 mesh, etc. The selection of sieve size is not limited by cost application restrictions.

[0053] The iron modification method involves immersing ground and sieved basalt fibers in an iron salt solution for 6-12 hours to physically deposit and load iron. The immersion temperature is 50-90℃. In this application, the iron salt solution is a ferric chloride solution, and its concentration is not limited, as long as it can submerge the basalt fibers and achieve iron loading. Preferably, the concentration is above 1M. After the reaction is complete, the fibers are washed with deionized water and dried to obtain iron-modified basalt fibers (Fe-MBF).

[0054] Organic polymer carbon material modification of basalt fiber

[0055] The method for modifying basalt fiber with organic polymer carbon material is as follows: the iron-modified basalt fiber Fe-MBF obtained above is immersed in sodium p-toluenesulfonate solution, pyrrole monomer is added, followed by iron salt solution, and the reaction is carried out at room temperature for 12-24 h to prepare iron-modified basalt particles through chemical oxidative polymerization reaction. In this step, the mass ratio of basalt fiber, sodium p-toluenesulfonate, pyrrole monomer, and trivalent iron is 5.0:9.7-10.8:3.4-4.2:5.5-6.6.

[0056] Regarding the sodium p-toluenesulfonate solution, this application does not limit its concentration, as long as the mass ratio of basalt fiber, sodium p-toluenesulfonate, pyrrole monomer, and ferric iron is 5.0:9.7-10.8:3.4-4.2:5.5-6.6, and it is sufficient to submerge the basalt fiber. Regarding the iron salt solution, which is an aqueous solution prepared from FeCl3·6H2O, this application does not limit its concentration, as long as the mass ratio of basalt fiber, sodium p-toluenesulfonate, pyrrole monomer, and ferric iron is 5.0:9.7-10.8:3.4-4.2:5.5-6.6.

[0057] After the reaction was completed, the basalt fibers were washed and purified with deionized water and ethanol to remove impurities and unloaded materials, and then placed in an oven to dry at 60-70°C.

[0058] Regarding staged calcination

[0059] The basalt fibers modified with iron and organic polymer carbon materials were then subjected to a calcination step in a nitrogen atmosphere. The calcination was carried out using a segmented calcination method.

[0060] First stage: Low-temperature pre-calcination (room temperature to 180-220°C, heating rate 4-6°C / min, holding time 25-40min) to remove moisture, volatile organic compounds or other impurities from the raw materials and avoid side reactions in the medium and high temperature stages;

[0061] The second stage: medium temperature reaction (raising the temperature to 350-400°C, heating rate 2-4°C / min, holding for 80-100min) promotes the initial reaction between the metal and the carbon source to form precursors or intermediate products, while avoiding excessive temperature that could lead to runaway reaction.

[0062] The third stage: high-temperature carbonization (temperature rises to 510-560°C, heating rate 1-3°C / min, holding for 100-130 min). The carbonization reaction is completed at this temperature to generate the target carbide and optimize the crystal structure and product properties.

[0063] This application modifies basalt fibers with iron and organic polymer carbon materials, which on the one hand increases the surface charge of basalt fibers, thereby enhancing their adsorption capacity for microorganisms and facilitating the adsorption and enrichment of microorganisms on their surface; on the other hand, it further improves the conductivity of basalt fibers.

[0064] Secondly, this application provides an iron-carbon modified basalt fiber particle electrode biocarrier, which is prepared by the above-mentioned method for preparing iron-carbon modified basalt fiber particle electrode biocarriers. The porosity of the iron-carbon modified basalt fiber particle electrode biocarrier is 90-93%, and the density is 1.03-1.15 g / cm³. 3The high porosity and low density of polypyrrole facilitate suspension, which is conducive to the enrichment and growth of microorganisms on its surface, enabling the enrichment and cultivation of marine anaerobic ammonia-oxidizing bacteria. Iron, as a basic substrate and potential energy source, plays a crucial role in the metabolism of anaerobic ammonia-oxidizing bacteria. In the presence of insoluble electron acceptors or electrodes, pre-enriched anaerobic ammonia-oxidizing bacteria can achieve nitrite-free electroactive ammonia oxidation through extracellular electron transfer, while the conductive carrier promotes biofilm formation and granulation processes. Polypyrrole (PPy) possesses advantages such as good biocompatibility, excellent electrical conductivity, high thermal conductivity, environmental stability, non-toxicity, high porosity, ease of synthesis, and low cost. Furthermore, PPy can reversibly transition between charged and neutral forms, further facilitating the adsorption and enrichment of microorganisms on its surface.

[0065] Iron-carbon modified basalt fiber particle electrode biocarriers enhance electron transfer capacity by forming a galvanic cell-like effect through the synergistic interaction between iron oxides (Fe²⁺ / Fe³⁺) and carbon materials, thereby promoting anammox denitrification.

[0066] Oxidation of Fe²⁺ (electron release):

[0067] Fe 2+ →Fe 3+ +e − In an anaerobic environment, Fe²⁺ can be oxidized to Fe³⁺ and release electrons. These electrons can be directly utilized by Anammox bacteria or denitrifying bacteria to drive denitrification reactions (such as NO⁻ reduction).

[0068] Reduction of Fe³⁺ (electron reception):

[0069] Fe 3+ +e − →Fe 2+ Fe³⁺ can accept electrons from organic matter or microbial metabolism and be reduced to Fe²⁺, forming an iron redox cycle that continuously transfers electrons.

[0070] Carbon materials, acting as a conductive network, integrate the redox activity of iron ions to form Fe-C composite active sites, synergistically enhancing electron utilization. The high specific surface area and porous structure of the iron-carbon modified basalt fiber particle electrode biocarrier provide attachment sites for Fe²⁺ / Fe³⁺ and microorganisms, increasing the reaction interface. Simultaneously, the iron-carbon modified basalt fiber particle electrode biocarrier is corrosion-resistant, maintaining the activity of the Fe-C composite structure over the long term.

[0071] Thirdly, this application provides a method for constructing an anaerobic denitrification granular sludge reactor. The key to constructing this reactor lies in the acclimatization and cultivation of marine sludge. Firstly, an anaerobic microbial denitrification reactor containing the marine sludge needs to be constructed. This reactor has good sealing performance, is equipped with a reaction zone and a sedimentation zone, and has a stirring device and a microbial retention device, as well as supporting inlet and outlet water facilities. The reactor is submerged in an opaque, insulated tank, and a temperature-controlled heating rod is built into the tank to maintain the water temperature at 28℃-32℃.

[0072] Sludge was extracted from marine sediment and washed 3-5 times with a washing solution for 10-15 minutes each time. After washing, the sludge was allowed to stand, and the impurities were poured off to obtain the desired marine sludge. The marine sludge was then inoculated into the aforementioned anaerobic microbial denitrification reactor (maintaining MLVSS at 3000-4000 mg / L) after its sealing performance was tested. At the same time, the aforementioned iron-carbon modified basalt fiber particle electrode biocarrier was added and stirred to promote the enrichment of microorganisms on the carrier. For every 300 ml of marine sludge inoculated, 4 g-6 g of iron-carbon modified basalt fiber particle electrode biocarrier was added. During the cultivation of the marine sludge, the stirring speed was maintained at 30-60 rpm to ensure that the iron-carbon modified basalt fiber particle electrode biocarrier was in full contact with the marine sludge. Due to the high porosity and low density of the iron-carbon modified basalt fiber particle electrode biocarrier, it was suspended in the reactor, which was conducive to the enrichment and growth of microorganisms on the surface, thus enabling the enrichment and cultivation of marine anaerobic ammonia-oxidizing bacteria.

[0073] Prepare artificially high-salinity nitrogen-containing wastewater: The sodium chloride concentration is 10-35 g / L. Add potassium dihydrogen phosphate, calcium chloride, potassium bicarbonate, magnesium sulfate, trace element I, and trace element II sequentially to the artificially high-salinity nitrogen-containing wastewater. Initially, the ammonia nitrogen and nitrite nitrogen contents are 100-120 mg / L. Control the pH of the artificially high-salinity nitrogen-containing wastewater to 7.0-8.0. The dosage per liter of artificially high-salinity nitrogen-containing wastewater is 0.01-0.05 mg of potassium dihydrogen phosphate, 0.1-0.5 mg of calcium chloride, 0.5-5 mg of potassium bicarbonate, 0.1-0.5 mg of magnesium sulfate, 0.1-2 mL of trace element I, and trace element II. 0.1-2 mL of the following trace element I is added: ethylenediaminetetraacetic acid 1-10 g / L, ferrous sulfate 1-10 g / L; and trace element II is added: ethylenediaminetetraacetic acid 10-20 g / L, perboric acid 0.01-0.05 g / L, manganese chloride 0.5-2 g / L, copper sulfate 0.1-0.5 g / L, zinc sulfate 0.1-1 g / L, nickel chloride 0.1-0.5 g / L, cobalt chloride 0.1-0.5 g / L, and sodium selenate 0.1-0.5 g / L. The prepared artificial high-salinity nitrogenous wastewater is then introduced into the reactor. In some embodiments, a peristaltic pump is used as the inlet device to supply water to the anaerobic microbial denitrification reactor. During continuous flow operation of the reactor, the hydraulic retention time (HRT) is calculated based on the effective reactor volume and inlet flow rate to maintain a set time (e.g., 10-24 hours, selected according to actual conditions).

[0074] The dissolved oxygen concentration in the influent is controlled below 0.5 mg / L by aeration with nitrogen gas to provide a suitable living environment for anaerobic ammonia-oxidizing bacteria.

[0075] The cultivation time of marine sludge can be selected according to the actual situation, as long as the MLVSS of marine sludge is not significantly reduced and the total nitrogen removal rate of marine sludge to influent reaches more than 70%. For example, it can be cultivated for 20-40 days. The number of days in the following examples does not constitute a limitation of this application.

[0076] Fourthly, this application provides an anaerobic denitrification granular sludge reactor, which is constructed using the above-mentioned construction method for the anaerobic denitrification granular sludge reactor. This anaerobic denitrification granular sludge reactor, constructed using iron-carbon modified basalt fiber granular electrode biological carrier, exhibits excellent denitrification performance in treating high-salinity nitrogen-containing wastewater (sodium chloride content of 10-35 g / L, especially 25-35 g / L), with ammonia nitrogen removal rate exceeding 93% and nitrite nitrogen removal rate exceeding 91%.

[0077] Fifthly, this application provides the application of the above-mentioned iron-carbon modified basalt fiber particle electrode biological carrier or the above-mentioned anaerobic denitrification granular sludge reactor in the treatment of high-salinity nitrogen-containing wastewater, wherein the sodium chloride content in the high-salinity nitrogen-containing wastewater is 10-35 g / L, especially 25-35 g / L.

[0078] Sixthly, this application provides a method for treating high-salinity nitrogen-containing wastewater, comprising passing the high-salinity nitrogen-containing wastewater into the aforementioned anaerobic denitrification granular sludge reactor, and controlling the temperature inside the reactor to be 28-32°C and the stirring speed to be 30-60 rpm, wherein the sodium chloride concentration in the high-salinity nitrogen-containing wastewater is 10-35 g / L, particularly 25-35 g / L, and the inorganic nitrogen in the high-salinity nitrogen-containing wastewater is a mixture of ammonia nitrogen and nitrite nitrogen, a mixture of ammonia nitrogen and nitrate nitrogen, or a mixture of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen.

[0079] In some of the embodiments, high-salinity nitrogen-containing wastewater is fed continuously with a hydraulic retention time of ≥10h.

[0080] Example 1: Preparation of iron-carbon modified basalt fiber particle electrode biocarrier

[0081] 1. Iron modification of basalt fibers

[0082] 10g of basalt fiber was soaked in 0.5L of acetone solvent, heated in a water bath to 40℃, and reacted for 3 hours. After drying, it was then placed in 0.5L of 1M sodium hydroxide solution and reacted at 40℃ for 12 hours. After the reaction was complete, the fiber was washed, dried, ground, and sieved (200 mesh). The scanning electron microscope image of the sieved basalt fiber is shown below. Figure 1 As shown, 5g of basalt fiber powder that has been ground and sieved was weighed and soaked in 0.5L of 1M iron salt solution and reacted at 60℃ for 8h. After the reaction was completed, it was washed with deionized water and dried to obtain iron-modified basalt fiber Fe-MBF for later use.

[0083] 2. Organic polymer carbon material modification of basalt fiber

[0084] 9.71 g of sodium p-toluenesulfonate was weighed and added to 0.5 L of deionized water. The mixture was stirred until fully dissolved to obtain a sodium p-toluenesulfonate solution. 5 g of Fe-MBF was immersed in the prepared sodium p-toluenesulfonate solution. 3.5 g of pyrrole monomer was slowly added dropwise, and the mixture was stirred for 5 min. Then, a prepared ferric chloride solution (prepared by weighing 27 g of FeCl3·6H2O and adding it to 0.1 L of deionized water, stirring until fully dissolved) was added dropwise. The mixture was stirred at room temperature for 20 h to prepare organic polymer-modified basalt particles via chemical oxidative polymerization. After the reaction, the modified basalt fibers were washed and purified with deionized water and ethanol, and then dried in an oven at 70 °C for later use. The scanning electron microscope image of the basalt fibers obtained in this step is shown below. Figure 2 As shown.

[0085] 3. Staged calcination

[0086] The basalt fibers prepared above were placed in a tube furnace for staged calcination in a nitrogen atmosphere.

[0087] First stage: Low-temperature preheating, heating to 200°C at a rate of 5°C / min, and holding for 30 minutes;

[0088] Second stage: medium temperature reaction, heating to 400°C at a rate of 3°C / min, and holding for 90min;

[0089] The third stage: high-temperature carbonization, heating to 550°C at a rate of 2°C / min, and holding for 120 minutes to complete the carbonization reaction, generating the target carbide iron-carbon modified basalt fiber particle electrode biocarrier. Figure 3 A scanning electron microscope image of an iron-carbon modified basalt fiber particle electrode biocarrier is shown. Figure 4 and Figure 5 The EDS elemental analysis diagram of the iron-carbon modified basalt fiber particle electrode biocarrier is shown. It can be seen that the surface is uniformly loaded with C and Fe elements, and the Si element is wrapped inside by the C element after polypyrrole carbonization. The distribution of each element is also shown in the table below. Figure 6 XPS images of C elements on the iron-carbon modified basalt fiber particle electrode biocarrier are shown, indicating that C elements were successfully loaded onto the surface of the iron-carbon modified basalt fiber particle electrode biocarrier. Figure 7 XPS plot of Fe on the iron-carbon modified basalt fiber particle electrode biocarrier is shown, indicating that Fe was successfully loaded onto the surface of the iron-carbon modified basalt fiber particle electrode biocarrier. The figure shows that the peaks at 728.0 eV and 711.2 eV are related to Fe. 3+ Related to Fe 2+ The binding energies of the peaks are 724.1 eV and 709.5 eV, respectively, and the satellite peak at 722.6 eV corresponds to Fe. 3+ The satellite peak at 715.4 eV corresponds to Fe 2+ .

[0090]

[0091] Example 2: Preparation of iron-carbon modified basalt fiber particle electrode biocarrier II

[0092] 1. Iron modification of basalt fibers

[0093] 10g of basalt fiber was soaked in 0.5L of acetone solvent, heated in a water bath to 38℃, and dried after 5h. Then it was placed in 0.5L of 1M hydrochloric acid solution and reacted at 20℃ for 24h. After the reaction was completed, it was washed, dried, ground and sieved (170 mesh). 5g of the ground and sieved basalt fiber powder was weighed and soaked in 0.5L of 2M iron salt solution and reacted at 50℃ for 12h. After the reaction was completed, it was washed with deionized water and dried to obtain iron-modified basalt fiber Fe-MBF for later use.

[0094] 2. Organic polymer carbon material modification of basalt fiber

[0095] 9.71 g of sodium p-toluenesulfonate was weighed and added to 0.5 L of deionized water. The mixture was stirred until fully dissolved to obtain a sodium p-toluenesulfonate solution. 3.4 g of pyrrole monomer was slowly added dropwise to the sodium p-toluenesulfonate solution prepared by soaking 5 g of Fe-MBF. After stirring for 5 min, a prepared ferric chloride solution was added dropwise (prepared by weighing 26.5 g of FeCl3·6H2O and adding it to 0.1 L of deionized water, stirring until fully dissolved). The mixture was stirred at room temperature for 12 h to prepare organic polymer carbon material modified basalt particles through chemical oxidative polymerization. After the reaction was completed, the modified basalt fibers were washed and purified with deionized water and ethanol, and then dried in an oven at 60 °C for later use.

[0096] 3. Staged calcination

[0097] The basalt fibers prepared above were placed in a tube furnace for staged calcination in a nitrogen atmosphere.

[0098] First stage: Low-temperature preheating, heating to 180°C at a rate of 4°C / min, and holding for 25 minutes;

[0099] Second stage: medium temperature reaction, heating to 350°C at a rate of 2°C / min, and holding for 80min;

[0100] The third stage: high-temperature carbonization, heating to 510°C at a rate of 1°C / min, and holding at this temperature for 100 minutes to complete the carbonization reaction and generate the target carbide. The relevant test results in this embodiment are similar to those in Example 1 and are omitted here.

[0101] Example 3: Preparation of iron-carbon modified basalt fiber particle electrode biocarrier

[0102] 1. Iron modification of basalt fibers

[0103] 10g of basalt fiber was soaked in 0.5L of acetone solvent, heated in a water bath to 42℃, reacted for 1h and then dried. Subsequently, it was placed in 0.5L of 1M sulfuric acid solution and reacted at 90℃ for 1h. After the reaction was completed, it was washed, dried and ground and sieved (230 mesh). 5g of the ground and sieved basalt fiber powder was weighed and soaked in 0.5L of 1M iron salt solution and reacted at 90℃ for 6h. After the reaction was completed, it was washed with deionized water and dried to obtain iron-modified basalt fiber Fe-MBF for later use.

[0104] 2. Organic polymer carbon material modification of basalt fiber

[0105] 10.8 g of sodium p-toluenesulfonate was weighed and added to 0.5 L of deionized water. The mixture was stirred until fully dissolved to obtain a sodium p-toluenesulfonate solution. 4.2 g of pyrrole monomer was slowly added dropwise to the sodium p-toluenesulfonate solution prepared by soaking 5 g of Fe-MBF. After stirring for 5 min, a prepared ferric chloride solution was added dropwise (prepared by weighing 31.3 g of FeCl3·6H2O and adding it to 0.1 L of deionized water, stirring until fully dissolved). The mixture was stirred at room temperature for 24 h to prepare organic polymer carbon material modified basalt particles through chemical oxidative polymerization. After the reaction was completed, the modified basalt fibers were washed and purified with deionized water and ethanol, and then dried in an oven at 65 °C for later use.

[0106] 3. Staged calcination

[0107] The basalt fibers prepared above were placed in a tube furnace for staged calcination in a nitrogen atmosphere.

[0108] First stage: Low-temperature preheating, heating to 220°C at a rate of 6°C / min, and holding for 40 minutes;

[0109] Second stage: medium temperature reaction, heat up to 400°C at a rate of 4°C / min, hold for 100min;

[0110] The third stage: high-temperature carbonization, heating to 560°C at a rate of 3°C / min, and holding at this temperature for 130 minutes to complete the carbonization reaction and generate the target carbide. The relevant detection diagrams in this embodiment are similar to those in Example 1 and are omitted here.

[0111] Example 4: Preparation of iron-carbon modified basalt fiber particle electrode biocarrier (Part IV)

[0112] 1. Iron modification of basalt fibers

[0113] 10g of basalt fiber was soaked in 0.5L of acetone solvent, heated in a water bath to 40℃, and reacted for 4 hours. After drying, it was placed in 0.5L of 1M sodium hydroxide solution and reacted at 40℃ for 12 hours. Then it was placed in 0.5L of 1M hydrogen peroxide solution and reacted at 50℃ for 6 hours. After the reaction was completed, it was washed, dried, ground and sieved (200 mesh). 5g of the ground and sieved basalt fiber powder was weighed and soaked in 0.5L of 1M iron salt solution and reacted at 70℃ for 4 hours. After the reaction was completed, it was washed with deionized water and dried to obtain iron-modified basalt fiber Fe-MBF for later use.

[0114] 2. Organic polymer carbon material modification of basalt fiber

[0115] 10.2 g of sodium p-toluenesulfonate was weighed and added to 0.5 L of deionized water. The mixture was stirred until fully dissolved to obtain a sodium p-toluenesulfonate solution. 5 g of Fe-MBF was immersed in the prepared sodium p-toluenesulfonate solution. 4.0 g of pyrrole monomer was slowly added dropwise. After stirring for 5 min, a prepared ferric chloride solution was added dropwise (prepared by weighing 28.9 g of FeCl3·6H2O and adding it to 0.1 L of deionized water, stirring until fully dissolved). The mixture was stirred at room temperature for 22 h to prepare organic polymer carbon material modified basalt particles through chemical oxidative polymerization. After the reaction was completed, the modified basalt fibers were washed and purified with deionized water and ethanol, and then dried in an oven at 70 °C for later use.

[0116] 3. Staged calcination

[0117] The basalt fibers prepared above were placed in a tube furnace for staged calcination in a nitrogen atmosphere.

[0118] First stage: Low-temperature preheating, heating to 200°C at a rate of 5°C / min, and holding for 30 minutes;

[0119] Second stage: medium temperature reaction, heating to 400°C at a rate of 3°C / min, and holding for 90 minutes;

[0120] The third stage: high-temperature carbonization, heating to 550°C at a rate of 2°C / min, and holding at this temperature for 120 minutes to complete the carbonization reaction and generate the target carbide. The relevant detection diagrams in this embodiment are similar to those in Example 1 and are omitted here.

[0121] Example 5: Construction of an Anaerobic Denitrification Granular Sludge Reactor

[0122] Sludge is extracted from marine sediment. The marine sludge is washed 3-5 times with a washing solution, each time for 10-15 minutes. After washing, it is allowed to stand, and the impurities washed out are poured off to obtain the desired marine sludge. (Reference) Figure 8The schematic diagram shows that 0.3 L of marine sludge was inoculated into an anaerobic microbial denitrification reactor whose sealing performance had been tested, maintaining an MLVSS of 4000 mg / L. Simultaneously, 5 g of the iron-carbon modified basalt fiber particle electrode biocarrier prepared in Example 1 was added. The entire reactor was immersed in an opaque, covered, insulated box equipped with a temperature-controlled heating rod, a pH monitoring system, and a speed controller, ensuring that the internal water temperature of the reactor was maintained at 30 ± 1 °C, the stirring speed at 30 rpm, and the pH value at 7 throughout the entire cultivation process.

[0123] The following formula was used to prepare simulated high-salinity nitrogen-containing wastewater. After the simulated high-salinity nitrogen-containing wastewater was prepared, it was aerated with high-purity nitrogen for more than 30 minutes to remove dissolved oxygen (<0.3 mg / L). Subsequently, a peristaltic pump was used to continuously feed water into the reactor, with a hydraulic retention time of 24 hours. The reactor was then operated stably for 20 days to allow the inoculated marine sludge to adapt to the new environment in the reactor and achieve the enrichment and cultivation of marine anaerobic ammonia-oxidizing bacteria. At this point, the MLVSS of the denitrifying granular sludge was not significantly reduced, and the total nitrogen removal rate of the denitrifying granular sludge from the influent reached more than 70%. The simulated high-salinity nitrogen-containing wastewater contained the following components: NH4+. + -N 100mg / L (prepared with NH4Cl), NO2 - -N 100mg / L (prepared with NaNO2), NaCl 10g / L, wherein per liter of simulated high-salinity nitrogenous wastewater, 0.01mg of potassium dihydrogen phosphate, 0.1mg of calcium chloride, 0.5mg of potassium bicarbonate, 0.1mg of magnesium sulfate, 0.1mL of trace element I, and 0.1mL of trace element II are added. The composition and content of trace element I are: 1g / L ethylenediaminetetraacetic acid and 1g / L ferrous sulfate; the composition and content of trace element II are: 10g / L ethylenediaminetetraacetic acid, 0.01g / L perboric acid, 0.5g / L manganese chloride, 0.1g / L copper sulfate, 0.1g / L zinc sulfate, 0.1g / L nickel chloride, 0.1g / L cobalt chloride, and 0.1g / L sodium selenate. All reagents used in this example were purchased from Shanghai Titan Biotechnology Co., Ltd. and Shanghai Yuanye Biotechnology Co., Ltd. Throughout the entire cultivation process, dissolved oxygen (DO) was strictly controlled, and in-situ testing was performed on the reactor effluent, with DO < 0.5 mg / L.

[0124] During this stage, the marine sludge in the reactor changes from black mud when it first enters the reactor to brown flocculent, then from brown flocculent to dark red flocculent sludge, and finally from dark red flocculent sludge to brick red large particles, exhibiting the typical characteristics of marine anaerobic ammonia oxidizing bacteria, thus achieving the enrichment and cultivation of marine anaerobic ammonia oxidizing bacteria.

[0125] Example 6: Construction of an Anaerobic Denitrification Granular Sludge Reactor (Part 2)

[0126] Sludge is extracted from marine sediment. The marine sludge is washed 3-5 times with a washing solution, each time for 10-15 minutes. After washing, it is allowed to stand, and the impurities washed out are poured off to obtain the desired marine sludge. (Reference) Figure 8 The schematic diagram shows that 0.3 L of marine sludge was inoculated into an anaerobic microbial denitrification reactor whose sealing performance had been tested, maintaining an MLVSS of 3000 mg / L. Simultaneously, 6 g of the iron-carbon modified basalt fiber particle electrode biocarrier prepared in Example 1 was added. The entire reactor was immersed in an opaque, covered, insulated box equipped with a temperature-controlled heating rod, a pH monitoring system, and a speed controller, ensuring that the internal water temperature of the reactor was maintained at 31 ± 1 °C, the stirring speed at 60 rpm, and the pH value at 8 throughout the entire cultivation process.

[0127] The following formula was used to prepare simulated high-salinity nitrogen-containing wastewater. After the simulated high-salinity nitrogen-containing wastewater was prepared, it was aerated with high-purity nitrogen for more than 30 minutes to remove dissolved oxygen (<0.3 mg / L) from the solution. Subsequently, a peristaltic pump was used to continuously feed water into the reactor, with a hydraulic retention time of 12 hours. The reactor was then operated stably for 40 days to allow the inoculated marine sludge to adapt to the new environment in the reactor and achieve the enrichment and cultivation of marine anaerobic ammonia-oxidizing bacteria. At this time, the MLVSS of the denitrifying granular sludge was not significantly reduced, and the total nitrogen removal rate of the denitrifying granular sludge from the influent reached more than 70%. The simulated high-salinity nitrogen-containing wastewater contained the following components: NH4+. + -N 120mg / L (prepared with NH4Cl), NO2 - -N 120mg / L (prepared with NaNO2), NaCl 35g / L, wherein per liter of simulated high-salinity nitrogenous wastewater, 0.05mg of potassium dihydrogen phosphate, 0.5mg of calcium chloride, 5mg of potassium bicarbonate, 0.5mg of magnesium sulfate, 2mL of trace element I, and 2mL of trace element II are added. The composition and content of trace element I are: 10g / L ethylenediaminetetraacetic acid and 10g / L ferrous sulfate; the composition and content of trace element II are: 20g / L ethylenediaminetetraacetic acid, 0.05g / L perboric acid, 2g / L manganese chloride, 0.5g / L copper sulfate, 1g / L zinc sulfate, 0.5g / L nickel chloride, 0.5g / L cobalt chloride, and 0.5g / L sodium selenate. All reagents used in this example were purchased from Shanghai Titan Biotechnology Co., Ltd. and Shanghai Yuanye Biotechnology Co., Ltd. Throughout the entire cultivation process, dissolved oxygen (DO) was strictly controlled, and in-situ testing was performed on the reactor effluent, with DO < 0.5 mg / L.

[0128] During this stage, the marine sludge in the reactor changes from black mud when it first enters the reactor to brown flocculent, then from brown flocculent to dark red flocculent sludge, and finally from dark red flocculent sludge to brick red large particles, exhibiting the typical characteristics of marine anaerobic ammonia oxidizing bacteria, thus achieving the enrichment and cultivation of marine anaerobic ammonia oxidizing bacteria.

[0129] Example 7: Treatment of High-Salinity Nitrogenous Simulated Wastewater

[0130] Simulated wastewater was introduced into the anaerobic microbial denitrification reactor of Example 5 as an example for denitrification treatment.

[0131] The reactor operates continuously with a hydraulic retention time of 24 hours and a water temperature maintained at 31℃±1℃. Simulated wastewater enters the reactor through an inlet pipe and a peristaltic pump. In the reactor, marine anaerobic ammonia-oxidizing bacteria use ammonia nitrogen as an electron donor and nitrite nitrogen as an electron acceptor to convert both into nitrogen gas, which is then discharged from the reactor, achieving efficient denitrification treatment of high-salinity nitrogen-containing simulated wastewater.

[0132] Simulated wastewater parameters: NH4 + -N 100mg / L, NO2 - -N 100mg / L, NaCl 10g / L. The simulated wastewater contained 0.01mg potassium dihydrogen phosphate, 0.1mg calcium chloride, 0.5mg potassium bicarbonate, 0.1mg magnesium sulfate, 0.1mL trace element I, and 0.1mL trace element II per liter. Trace element I consisted of 1g / L ethylenediaminetetraacetic acid (EDTA) and 1g / L ferrous sulfate. Trace element II consisted of 10g / L EDTA, 0.01g / L perboric acid, 0.5g / L manganese chloride, 0.1g / L copper sulfate, 0.1g / L zinc sulfate, 0.1g / L nickel chloride, 0.1g / L cobalt chloride, and 0.1g / L sodium selenate. All reagents used in this example were purchased from Shanghai Titan Biotechnology Co., Ltd. and Shanghai Yuanye Biotechnology Co., Ltd. After the influent solution is prepared, it is aerated with high-purity nitrogen for more than 30 minutes to remove dissolved oxygen (<0.3 mg / L) from the solution.

[0133] Testing showed that, within 0-30 days, this application significantly improved the removal of ammonia nitrogen and nitrite nitrogen from the simulated wastewater, with ammonia nitrogen removal rates exceeding 93% and nitrite nitrogen removal rates exceeding 91%. This embodiment also included a control experiment 1, in which the iron-carbon modified basalt fiber granular electrode biocarrier prepared in this application was not added during the construction of the anaerobic denitrification granular sludge reactor; all other parameters remained the same. The treatment results of Example 7 and the control experiment are shown in Table 1 below. It can be seen that the presence or absence of the iron-carbon modified basalt fiber granular electrode biocarrier prepared in this application significantly affects the subsequent denitrification effect.

[0134] Table 1

[0135]

[0136] In this embodiment, after 140 days of reactor operation, the performance parameters of Anammox bacteria under high-salt and high-nitrogen environments are as follows: Sludge performance: Sludge concentration (MLSS): 3000-4000 mg / L, Sludge settling property (SVI): 50-70 mL / g, Sludge activity (SOUR): 0.5-0.8 mg O2 / g MLSS·h. Nitrogen removal performance: Ammonia nitrogen removal rate: 93.5%, Nitrite nitrogen removal rate: 91.2%.

[0137] Example 8: Treatment of High-Salinity Nitrogen-Containing Simulated Wastewater (Part 2)

[0138] Simulated wastewater was introduced into the anaerobic microbial denitrification reactor of Example 5 as an example for denitrification treatment.

[0139] The reactor operates continuously with a hydraulic retention time of 24 hours and a water temperature maintained at 30℃±1℃. Simulated wastewater enters the reactor through an inlet pipe and a peristaltic pump. In the reactor, marine anaerobic ammonia-oxidizing bacteria use ammonia nitrogen as an electron donor and nitrite nitrogen as an electron acceptor to convert both into nitrogen gas, which is then discharged from the reactor, achieving efficient denitrification treatment of high-salinity nitrogen-containing simulated wastewater.

[0140] Simulated wastewater parameters: NH4 + -N 110mg / L, NO2 - -N 120mg / L, NaCl 35g / L. The simulated wastewater contained 0.01mg potassium dihydrogen phosphate, 0.1mg calcium chloride, 0.5mg potassium bicarbonate, 0.1mg magnesium sulfate, 0.1mL trace element I, and 0.1mL trace element II per liter. Trace element I consisted of 1g / L ethylenediaminetetraacetic acid (EDTA) and 1g / L ferrous sulfate. Trace element II consisted of 10g / L EDTA, 0.01g / L perboric acid, 0.5g / L manganese chloride, 0.1g / L copper sulfate, 0.1g / L zinc sulfate, 0.1g / L nickel chloride, 0.1g / L cobalt chloride, and 0.1g / L sodium selenate. All reagents used in this example were purchased from Shanghai Titan Biotechnology Co., Ltd. and Shanghai Yuanye Biotechnology Co., Ltd. After the influent solution is prepared, it is aerated with high-purity nitrogen for more than 30 minutes to remove dissolved oxygen (<0.3 mg / L) from the solution.

[0141] Testing showed that, within 0-30 days, this application significantly improved the removal of ammonia nitrogen and nitrite nitrogen from the simulated wastewater, with an ammonia nitrogen removal rate exceeding 91% and a nitrite nitrogen removal rate approaching 90%. This embodiment also included a control experiment 2, in which the iron-carbon modified basalt fiber granular electrode biocarrier prepared in this application was not added during the construction of the anaerobic denitrification granular sludge reactor; all other parameters remained the same. The treatment results of Example 7 and the control experiment are shown in Table 2 below. It can be seen that the presence or absence of the iron-carbon modified basalt fiber granular electrode biocarrier prepared in this application significantly affects the subsequent denitrification effect.

[0142] Table 2

[0143]

[0144] In this embodiment, after 140 days of reactor operation, the performance parameters of Anammox bacteria under high-salt and high-nitrogen conditions are as follows: Sludge performance: Sludge concentration (MLSS): 3000-4000 mg / L, Sludge settling property (SVI): 50-70 mL / g, Sludge activity (SOUR): 0.5-0.8 mg O2 / g MLSS·h. Nitrogen removal performance: Ammonia nitrogen removal rate: 93.1%, Nitrite nitrogen removal rate: 91.4%.

[0145] Example 9: Treatment of High-Salinity Nitrogenous Actual Wastewater

[0146] High-salinity nitrogen-containing actual wastewater was introduced into the anaerobic microbial denitrification reactor of Example 5 for denitrification treatment. The hydraulic retention time was 24 hours, and the water temperature was maintained at 30℃±1℃. Wastewater parameters: NH4 + -N 100-200mg / L, NO2 - -N 100-260 mg / L, NaCl 25-35 g / L. Referring to Examples 7 or 8, add appropriate amounts of potassium dihydrogen phosphate, calcium chloride, potassium bicarbonate, magnesium sulfate, trace element I, and trace element II per liter of simulated wastewater. After the influent solution is prepared, aerate it with high-purity nitrogen for more than 30 minutes to remove dissolved oxygen (<0.3 mg / L).

[0147] Testing showed that during 30 days of stable operation after treatment, this application demonstrated significant removal effects on nitrite and ammonia nitrogen in actual wastewater with different sodium chloride concentrations, with ammonia nitrogen removal rates exceeding 93% and nitrite nitrogen removal efficiency exceeding 91%. This demonstrates that this application achieves highly efficient denitrification of high-salinity nitrogen-containing wastewater by incorporating iron-carbon modified basalt fiber particle electrode biocarriers into the reactor construction process to acclimate and cultivate marine anaerobic ammonia-oxidizing bacteria.

[0148] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A method for preparing an iron-carbon modified basalt fiber particle electrode biocarrier, characterized in that, Includes the following steps: S a 1. After pretreatment and etching, the basalt fibers are ground and sieved, then soaked in an iron salt solution for 6-12 hours at a temperature of 50-90℃. S a 2. Step S a The obtained basalt fibers were soaked in sodium p-toluenesulfonate solution, followed by the addition of pyrrole monomer and then iron salt solution. The reaction was carried out at room temperature for 12-24 h. The mass ratio of basalt fibers, sodium p-toluenesulfonate, pyrrole monomer and ferric iron was 5.0:9.7-10.8:3.4-4.2:5.5-6.

6. S a 3. The basalt fibers obtained in step S2 are calcined in stages, wherein... First stage: Raise the temperature to 180-220°C and maintain the temperature for 25-40 minutes. Second stage: Raise the temperature to 350-400°C and maintain the temperature for 80-100 minutes. Third stage: Raise the temperature to 510-560°C and keep it warm for 100-130 minutes.

2. The method for preparing the iron-carbon modified basalt fiber particle electrode biocarrier as described in claim 1, characterized in that, Step S a The pretreatment in section 1 includes: immersing basalt fibers in acetone solvent, heating to 38-42℃ and reacting for more than 1 hour, and / or Step S a The etching process in 1 includes: placing basalt fibers in an etching solution and reacting at 20-90°C for 1-24 hours, wherein the etching solution includes one or more of hydrochloric acid solution, sulfuric acid solution, hydrogen peroxide solution and sodium hydroxide solution.

3. The method for preparing the iron-carbon modified basalt fiber particle electrode biocarrier as described in claim 2, characterized in that, Step S a The etching process in section 1 includes: first, placing the basalt fiber in hydrochloric acid solution, sulfuric acid solution, or sodium hydroxide solution and reacting at 20-90℃ for 2-24 hours, and then placing it in hydrogen peroxide solution and reacting at 40-90℃ for 1-12 hours.

4. The method for preparing the iron-carbon modified basalt fiber particle electrode biocarrier as described in claim 1, characterized in that, Step S a Step 3 also includes: step S a The basalt fibers obtained in step 2 were washed and purified with water and ethanol, and then dried at 60-70℃.

5. A bio-carrier for iron-carbon modified basalt fiber particles as electrodes, characterized in that, The biocarrier for iron-carbon modified basalt fiber particles was prepared by any one of claims 1-4.

6. The iron-carbon modified basalt fiber particle electrode biocarrier as described in claim 5, characterized in that, The iron-carbon modified basalt fiber particle electrode biocarrier has a porosity of 90-93% and a density of 1.03-1.15 g / cm³. 3 .

7. The application of the iron-carbon modified basalt fiber particle electrode biocarrier as described in claim 5 or 6 in the treatment of high-salinity nitrogen-containing wastewater, wherein, The sodium chloride content in the high-salinity nitrogen-containing wastewater is 10-35 g / L.

8. A method for constructing an anaerobic denitrification granular sludge reactor, characterized in that, Includes the following steps: S b 1. Inoculate the pretreated marine sediment into the reactor; S b 2. Add the iron-carbon modified basalt fiber particle electrode biocarrier as described in any one of claims 5-6; S b 3. Cultivate and acclimate the product for 20-40 days at a temperature of 28-32℃ and a stirring speed of 30-60 rpm. The influent ammonia nitrogen concentration is 100-120 mg / L, nitrite nitrogen concentration is 100-120 mg / L, sodium chloride concentration is 10-35 g / L, pH is 7.0-8.0, and hydraulic retention time is 10-24 hours.

9. An anaerobic denitrification granular sludge reactor, characterized in that, The anaerobic denitrification granular sludge reactor is constructed using the method described in claim 8.

10. The application of the anaerobic denitrification granular sludge reactor as described in claim 9 in the treatment of high-salinity nitrogen-containing wastewater, wherein, The sodium chloride content in the high-salinity nitrogen-containing wastewater is 10-35 g / L.

11. A method for treating high-salinity nitrogen-containing wastewater, characterized in that, This includes feeding the high-salinity nitrogen-containing wastewater into the anaerobic denitrification granular sludge reactor as described in claim 9, and controlling the temperature inside the reactor to be 28-32°C and the stirring speed to be 30-60 rpm.

Images