A reagent for treating high ammonia nitrogen wastewater

Abstract

The present invention discloses a reagent for treating high-ammonia-nitrogen wastewater, which comprises the following components in parts by weight: 8-12 parts of composite bacteria, 5-10 parts of D-sodium glucuronate, 40-60 parts of modified carrier, and 80-120 parts of nutrients. Compared with the prior art, the reagent for treating high-ammonia-nitrogen wastewater prepared by the present invention can effectively reduce pollutants such as ammonia nitrogen, COD, BOD, TSS, and SS, and is applicable to treating various types of organic wastewater with high salinity (1%-5%), solves the problem that it is difficult to meet the discharge standards for high-salinity sewage, and can be widely used in high-salinity sewage industries such as high-salinity petrochemical industry, high-salinity pharmaceutical industry, high-salinity paper-making industry, high-salinity leather industry, and high-salinity printing and dyeing industry.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, and particularly to a reagent for treating high-ammonia-nitrogen wastewater. Background Art

[0002] As a quasi-public welfare product, the price of sewage treatment has been relatively low for a long time. With the improvement of the future market pricing mechanism and the greater participation of social capital, the price of sewage treatment will inevitably increase, winning a greater profit space for sewage treatment enterprises. The research and development of high-salt and high-ammonia-nitrogen wastewater treatment processes, which have good effects in removing organic matter, salts, ammonia nitrogen, and heavy metals, will surely have a greater development space and market prospect.

[0003] At present, the existing technologies for high-ammonia-nitrogen wastewater treatment reagents include the following: Biological method: Using microorganisms to degrade and transform ammonia nitrogen in wastewater. Common methods include anaerobic treatment, aerobic treatment, and nitrification / denitrification treatment, etc. By reasonably regulating the microbial community and cultivation conditions, ammonia nitrogen in high-ammonia-nitrogen wastewater can be effectively removed. Chemical method: Using chemical reagents to carry out precipitation, oxidation, or reduction reactions on ammonia nitrogen in wastewater to convert it into harmless substances or forms that are easy to treat. Commonly used chemical reagents include ferric chloride, oxidants (such as hydrogen peroxide, potassium permanganate), ammonium sulfate, etc. Adsorption method: Using adsorption materials to adsorb ammonia nitrogen in wastewater and remove it from the wastewater. Common adsorbents include activated carbon, ion exchange resins, natural adsorption materials, etc. Membrane separation method: Using membrane technology to separate and concentrate wastewater, and separating ammonia nitrogen in the wastewater through the selective transfer process of the membrane. Common membrane separation technologies include ultrafiltration, nanofiltration, and reverse osmosis, etc. Other physicochemical methods: including electrolysis method, ozone oxidation method, ultraviolet photocatalytic oxidation method, etc. These methods use physicochemical effects to treat and transform ammonia nitrogen in wastewater.

[0004] Among them, the biological methods include anaerobic ammonium oxidation: This is a process that uses anaerobic bacteria to directly convert ammonia nitrogen into nitrogen gas. By combining ammonia nitrogen and nitrite in an anoxic environment, nitrogen gas and water are produced. This method has the advantages of high efficiency, energy conservation, and low demand for carbon sources. Aerobic / anaerobic treatment: This method combines aerobic and anaerobic processes. Through aerobic treatment, ammonia nitrogen in wastewater is converted into nitrite and nitrate, and then through anaerobic treatment, nitrate is reduced to nitrogen gas. This treatment method usually requires two different biological reactors: an aerobic reactor and an anaerobic reactor. Nitrification / denitrification treatment: This is a commonly used method for ammonia nitrogen removal, in which nitrification and denitrification are completed by different microbial communities. In the nitrification process, ammonia nitrogen is first oxidized to nitrite by ammonia-oxidizing bacteria, and then further oxidized to nitrate by nitrite-oxidizing bacteria. In the denitrification process, nitrate is reduced to nitrogen gas by denitrifying bacteria. Constructed wetland treatment: A constructed wetland is a method that uses a complex ecosystem of wetland plants and microorganisms to treat wastewater. Wastewater passes through the plant roots and wetland media, interacts with the microorganisms in the wetland, and converts ammonia nitrogen into harmless substances through biodegradation and adsorption. Constructed wetland treatment has the advantages of low energy consumption, low operating costs, and good landscape effects.

[0005] However, the biological methods have the following disadvantages: Longer response time: Compared with some physicochemical methods, biological methods may require a longer response time during the treatment process. The growth and metabolic processes of microorganisms require a certain amount of time, especially for some slowly growing microbial communities. Sensitive to environmental conditions: Biological methods have higher requirements for environmental conditions. Microorganisms are sensitive to environmental factors such as temperature, pH value, and oxygen supply, and appropriate environmental conditions need to be strictly controlled and maintained. Affected by wastewater composition: The composition and water quality characteristics of wastewater will affect the treatment effect of biological methods. Some special components or toxic substances may inhibit the growth and activity of the microbial community, thus affecting the treatment effect.

[0006] It is necessary to evaluate and balance these advantages and disadvantages according to specific circumstances and select a suitable biological method technology for the treatment of high ammonia nitrogen wastewater.

[0007] The Chinese authorized invention patent CN114835265B discloses a method for treating high-ammonia-nitrogen wastewater, including: filling a composite biological filler in an aerobic device, and adding an activated and domesticated composite microbial strain to the aerobic device filled with the composite biological filler; decomposing the ammonia nitrogen in the pretreated high-ammonia-nitrogen wastewater through the activated and domesticated composite microbial strain on the composite biological filler. This invention solves the technical problem of how to convert and remove ammonia nitrogen in high-ammonia-nitrogen wastewater at low cost without generating secondary pollution or solid waste. This invention provides a biological treatment approach for treating high-ammonia-nitrogen wastewater; greatly improves the ammonia-nitrogen tolerance concentration of the biological treatment of high-ammonia-nitrogen wastewater; greatly reduces the investment cost and operating cost of the treatment facilities for high-ammonia-nitrogen wastewater, and at the same time avoids the problem of secondary pollution or solid waste generated during the treatment process. However, the ammonia nitrogen and COD absorption effects of the treatment method prepared by this invention are poor, it is not resistant to chemicals, and it is not applicable to the field of high-ammonia-nitrogen wastewater. Summary of the Invention

[0008] In view of the disadvantages of poor ammonia nitrogen and COD absorption effects and poor chemical resistance of the high-ammonia-nitrogen wastewater treatment reagent in the prior art, the technical problem to be solved by the present invention is to provide a high-ammonia-nitrogen wastewater treatment reagent.

[0009] In order to achieve the above-mentioned invention purpose, the present invention adopts the following technical scheme:

[0010] A high-ammonia-nitrogen wastewater treatment reagent contains the following components by weight: 8-12 parts of composite bacteria, 5-10 parts of D-sodium glucuronate, 40-60 parts of modified carrier, and 80-120 parts of nutrients.

[0011] The nutrients include the following components in concentrations: glucose 8-12 g / L, peptone 8-12 g / L, sodium chloride 15-25 g / L, lauryl borate 0.01-0.03 g / L, magnesium chloride 8-9 g / L, sodium sulfate 2-4 g / L, calcium chloride 1-2 g / L, sodium silicate 3-5 mg / L, yeast extract 0.5-2 g / L, potassium chloride 0.4-0.6 g / L, ammonium nitrate 1-2 mg / L, sodium bicarbonate 0.1-0.2 g / L, disodium hydrogen phosphate 6-8 mg / L, ferric sulfate 0.01-0.02 g / L, potassium bromide 0.04-0.06 g / L, strontium dichloride 0.01-0.03 g / L, and sodium fluoride 1-3 mg / L. The balance is water. The final pH of the culture medium is adjusted to 6.5-7.5 with a buffer reagent, and the culture medium is autoclaved at 100-125 °C for 10-50 min to obtain the nutrients.

[0012] The buffer reagent is an aqueous boric acid solution with a concentration of 0.1-0.3 mg / L or an aqueous sodium bicarbonate solution with a concentration of 40-60 mg / L.

[0013] The preparation method of the modified carrier is as follows, by weight:

[0014] S1. Add 8 - 12 parts of acetonitrile and 8 - 12 parts of acetic acid to 400 - 600 parts of water, stir and mix at 100 - 500 rpm for 10 - 50 min, then add 1 - 3 parts of chitosan, stir at 100 - 500 rpm for 1 - 3 h to obtain a chitosan solution; Add 1 - 3 parts of benzoic acid compounds to 10 - 30 parts of acetonitrile, then add 2 - 3 parts of propane compounds and 1 - 2 parts of N - acryloxysuccinimide, stir at 100 - 500 rpm for 10 - 50 min, then add it to the chitosan solution, stir at 25 - 35 °C and 100 - 500 rpm for 10 - 20 h, add 150 - 300 parts of acetone for precipitation to obtain a chitosan derivative;

[0015] S2. Add the chitosan derivative prepared in step S1 to 80 - 120 parts of 0.5 - 2 wt% aqueous acetic acid solution, add 40 - 60 parts of 0.5 - 2 mol / L aqueous oxalyl dihydrazide solution, stir at 100 - 500 rpm for 5 - 15 min, add 0.1 - 0.3 parts of zinc powder, stir at 25 - 35 °C and 100 - 500 rpm for half an hour, filter and collect the solution, then dropwise add 0.5 - 2 mol / L aqueous NaOH solution to adjust the pH to neutral to obtain modified chitosan;

[0016] S3. Add 4 - 6 parts of the modified chitosan prepared in step S2 to 80 - 120 parts of 0.5 - 2 wt% aqueous acetic acid solution, then add 1 - 3 parts of calcium chloride, stir at 100 - 300 rpm for 10 - 30 min, neutralize the pH to neutral with 0.4 - 0.6 mol / L aqueous sodium bicarbonate solution to obtain the modified carrier.

[0017] Preferably, the preparation method of the modified carrier is as follows, by weight:

[0018] S1. Add 8 - 12 parts of acetonitrile and 8 - 12 parts of acetic acid to 400 - 600 parts of water, stir and mix at 100 - 500 rpm for 10 - 50 min, then add 1 - 3 parts of chitosan, stir at 100 - 500 rpm for 1 - 3 h to obtain a chitosan solution; Add 1 - 3 parts of benzoic acid compounds to 10 - 30 parts of acetonitrile, then add 2 - 3 parts of propane compounds and 1 - 2 parts of N - acryloxysuccinimide, stir at 100 - 500 rpm for 10 - 50 min, then add it to the chitosan solution, stir at 25 - 35 °C and 100 - 500 rpm for 10 - 20 h, add 150 - 300 parts of acetone for precipitation to obtain a chitosan derivative;

[0019] S2. Add the chitosan derivative prepared in step S1 into 80 - 120 parts of 0.5 - 2 wt% acetic acid aqueous solution, add 40 - 60 parts of 0.5 - 2 mol / L oxalyl dihydrazide aqueous solution, stir at 100 - 500 rpm for 5 - 15 min, add 0.1 - 0.3 parts of zinc powder, stir at 100 - 500 rpm for half an hour at 25 - 35 °C, filter to collect the solution, then dropwise add 0.5 - 2 mol / L NaOH aqueous solution to adjust the pH to neutral to obtain the modified chitosan;

[0020] S3. Add 0.05 - 0.2 parts of montmorillonite into 15 - 25 parts of water, ultrasonically oscillate at 200 - 500 W for 5 - 20 min to obtain a suspension. Add the suspension and 1 - 3 parts of polyethyleneimine into 50 - 100 parts of 0.5 - 2 mol / L sodium hydroxide aqueous solution, stir at 100 - 300 rpm for 10 - 60 min at 40 - 60 °C to obtain mixture A; then add 0.4 - 0.6 parts of the modified chitosan prepared in step S2 into 20 - 40 parts of 0.4 - 0.6 wt% acetic acid aqueous solution to obtain a modified chitosan solution; slowly drop the modified chitosan solution into mixture A at a dropping rate of 0.1 - 0.3 mL / min, then add 8 - 12 parts of 10 - 28 wt% isovaleraldehyde propylene glycol acetal aqueous solution, stir at 100 - 500 rpm for 4 - 8 h at 40 - 60 °C, then filter and collect the solid at 40 - 60 °C, and dry for 10 - 30 h to obtain the composite material;

[0021] S4. Add 4 - 6 parts of the composite material prepared in step S3 into 80 - 120 parts of 0.5 - 2 wt% acetic acid aqueous solution, add 1 - 3 parts of calcium chloride, stir at 100 - 300 rpm for 10 - 30 min, and neutralize the pH to neutral with 0.4 - 0.6 mol / L sodium bicarbonate aqueous solution to obtain the modified carrier.

[0022] Preferably, the benzoic acid compound is one of 3,4 - dihydroxy - 5 - nitrobenzoic acid and 3 - hydroxy - 4 - nitrobenzoic acid.

[0023] Preferably, the propane compound is one of (2 - chloroethoxy) cyclopropane and epichlorohydrin.

[0024] A preparation method of a high ammonia - nitrogen wastewater treatment reagent is as follows:

[0025] Weigh each raw material by weight parts. Add sodium D-glucuronate into water with a mass 5 - 8 times that of sodium D-glucuronate, stir at 100 - 500 rpm for 10 - 30 min, add the composite bacteria, stir at 10 - 80 rpm for 10 - 50 min, then put the modified carrier and nutrients into a constant temperature incubator after stirring at 50 - 200 rpm for 10 - 50 min, aerobically culture at 25 - 35 °C, and keep the dissolved oxygen content at 1 - 5 mg / L. Replace half of the volume of nutrients every day to ensure that the microorganisms have sufficient nutrition. After culturing for 30 - 60 d, take it out, rinse it clean with physiological saline to obtain a high ammonia nitrogen wastewater treatment reagent.

[0026] In the present invention, sodium D-glucuronate can endow the carrier with certain strength, and chitosan increases biocompatibility, enabling good growth of bacteria. With the addition of chitosan, the diffusion of chitosan molecules in the immobilized bacteria spheres increases the degree and thickness of the membrane formation, thereby immobilizing more bacteria and promoting the removal of ammonia nitrogen. At the same time, chitosan and sodium D-glucuronate are combined through the reaction between amino and carboxyl groups, making the immobilized bacteria spheres more stable and enhancing their pH resistance. Compared with the bacteria immobilized by single sodium D-glucuronate, the bacteria immobilized by chitosan - sodium D-glucuronate show better ammonia nitrogen removal efficiency. This may be due to the increase in the number of immobilized bacteria resulting in an increase in microbial action.

[0027] Strong acidic and strong basic conditions will damage the immobilized bacterial carrier, thereby reducing the role of microorganisms. This may be because a large number of hydrogen ions in the strong acidic environment affect the electrical changes on the surface of bacteria, and nucleic acids and proteins will denature in the strong basic environment, both of which will lead to cell death and corrode the immobilized bacterial microspheres. The modified carrier is spherical after being wrapped, with good elasticity, permeability and mechanical strength. The internal shape of the modified carrier is irregular honeycomb-like and porous structure, providing a larger surface area for bacteria loading or ammonia nitrogen adsorption.

[0028] On the one hand, the high porosity and high molecular weight of sodium D-glucuronate enable the immobilized bacteria spheres to have high mechanical strength, thereby reducing the transfer resistance of ammonia nitrogen in the immobilized bacteria phase. On the other hand, the biocompatibility of the modified carrier enables bacteria to adapt to the environment in a shorter time, increasing the density of bacteria in the microspheres. These two reasons can improve the ammonia nitrogen removal rate and enhance its pH resistance. Further, montmorillonite is successfully embedded in the organic polymer, effectively increasing the specific surface area of the organic polymer, while reducing the aggregation of montmorillonite particles and providing more binding sites for adsorbing toxic metals in the polluted environment. This may be because the modified carrier surface has higher electronegativity or more abundant active sites, and toxic metals are more easily adsorbed.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] The high ammonia nitrogen wastewater treatment reagent prepared by the present invention can effectively reduce pollutants such as ammonia nitrogen, COD, BOD, TSS, SS, etc., and is suitable for treating various types of high-salinity (1%~5%) organic wastewater, solving the problem that high-salinity wastewater discharge is difficult to meet standards.

[0031] The high-ammonia nitrogen wastewater treatment reagent prepared by the invention can be widely used in high-salinity wastewater industries such as high-salinity petrochemical industry, high-salinity pharmaceutical industry, high-salinity papermaking, high-salinity leather, and high-salinity printing and dyeing.

[0032] The high-ammonia nitrogen wastewater treatment reagent of the present invention obtains a modified carrier with good performance and a suitable nutrient composition through precise steps and condition control. The wastewater treatment reagent prepared by using the modified carrier has better adsorption capacity and chemical stability compared with traditional chitosan. The synthesis steps of chitosan derivatives and composite materials are introduced in the preparation process of the modified carrier, so that it has more adsorption sites and active groups, and improves the adsorption effect on ammonia nitrogen and COD in wastewater.

[0033] The composition of the nutrients in the present invention is carefully designed, including a variety of organic and inorganic components, providing nutrients required for microbial growth and metabolism. At the same time, half of the volume of nutrients is replaced every day to ensure that the microorganisms have sufficient nutrient supply, thereby enhancing the effect of wastewater treatment and the growth activity of microorganisms.

[0034] The present invention adopts a constant temperature incubator and an aerated culture method to maintain the dissolved oxygen content at 3 mg / L at 30° C., thereby providing suitable temperature and oxygen supply conditions for the growth of halophilic microorganisms and wastewater treatment.

[0035] The method for preparing a high-ammonia nitrogen wastewater treatment reagent of the present invention has the advantages of a fine and controllable preparation process, optimization of modified carriers and nutrients, application of buffer reagents, and high-temperature aeration culture conditions. These advantages and beneficial effects are expected to improve the efficiency of wastewater treatment and the growth activity of microorganisms, thereby achieving a better high-ammonia nitrogen wastewater treatment effect. DETAILED DESCRIPTION

[0036] Main sources of substances:

[0037] Composite bacteria: Guangzhou Pasteur Biotechnology Co., Ltd., product number: BSD-Bio-001, colony count: 300 billion cfu / g.

[0038] Chitosan: Zhuhai Weijia Food Additive Co., Ltd., model: 001.

[0039] Peptone: Jinan Xiaoshi Chemical Co., Ltd., product number: XSHG-002, prepared by hydrolysis of soybean powder with papain and the like.

[0040] Example 1

[0041] The preparation method of a high ammonia-nitrogen wastewater treatment reagent is as follows:

[0042] Add 8 g of D-sodium glucuronate to 50 g of water, stir at 200 rpm for 20 min, add 10 g of composite bacteria, stir at 50 rpm for 30 min, then put 50 g of modified carrier and 100 g of nutrients into a constant temperature incubator after stirring at 100 rpm for 30 min, aerate and culture at 30 °C, and keep the dissolved oxygen content at 3 mg / L. Replace half of the volume of nutrients every day to ensure that the microorganisms have sufficient nutrients. After culturing for 45 d, take it out, rinse it with physiological saline, and obtain the high ammonia-nitrogen wastewater treatment reagent.

[0043] The nutrients include the following components at the following concentrations: glucose 10 g / L, peptone 10 g / L, sodium chloride 20 g / L, lauryl borate 0.02 g / L, magnesium chloride 8.8 g / L, sodium sulfate 3 g / L, calcium chloride 1.8 g / L, sodium silicate 4 mg / L, yeast extract 1 g / L, potassium chloride 0.5 g / L, ammonium nitrate 1.5 mg / L, sodium bicarbonate 0.15 g / L, disodium hydrogen phosphate 7 mg / L, ferric sulfate 0.015 g / L, potassium bromide 0.05 g / L, strontium dichloride 0.02 g / L, and sodium fluoride 2 mg / L. The balance is water. Adjust the final pH of the culture medium to 7 with a buffer reagent, and autoclave the culture medium at 120 °C for 30 min to obtain the nutrients.

[0044] The buffer reagent is an aqueous boric acid solution with a concentration of 0.2 mg / L.

[0045] The preparation method of the modified carrier is as follows:

[0046] S1. Add 10 g of acetonitrile and 10 g of acetic acid to 500 g of water, stir and mix at 200 rpm for 20 min, then add 2 g of chitosan, stir at 400 rpm for 2 h to obtain a chitosan solution; add 2 g of 3,4-dihydroxy-5-nitrobenzoic acid to 20 g of acetonitrile, then add 2.5 g of (2-chloroethoxy) cyclopropane and 1.5 g of N-acryloxysuccinimide, stir at 200 rpm for 30 min, then add it to the chitosan solution, stir at 300 rpm at 30 °C for 15 h, and add 200 g of acetone to precipitate to obtain a chitosan derivative;

[0047] S2. Add the chitosan derivative prepared in step S1 to 100 g of 1 wt% acetic acid aqueous solution, add 50 g of 1 mol / L oxalyl dihydrazide aqueous solution, stir at 200 rpm for 10 min, add 0.2 g of zinc powder, stir at 200 rpm at 30 °C for half an hour, filter and collect the solution, then dropwise add 1 mol / L NaOH aqueous solution to adjust the pH to neutral to obtain modified chitosan;

[0048] S3. Add 0.1 g of montmorillonite to 20 g of water, ultrasonically oscillate at 400 W for 10 min to obtain a suspension. Add the suspension and 1.5 g of polyethyleneimine to 80 g of 1 mol / L sodium hydroxide aqueous solution, stir at 200 rpm at 50 °C for 40 min to obtain mixture A; then add 0.5 g of the modified chitosan prepared in step S2 to 30 g of 0.5 wt% acetic acid aqueous solution to obtain a modified chitosan solution; slowly drop the modified chitosan solution into mixture A at a dropping rate of 0.2 mL / min, then add 10 g of 25 wt% isovaleraldehyde propylene glycol acetal aqueous solution, stir at 200 rpm at 50 °C for 6 h, then filter and collect the solid at 50 °C, and dry for 24 h to obtain a composite material;

[0049] S4. Add 5 g of the composite material prepared in step S3 to 100 g of 1 wt% acetic acid aqueous solution, then add 2 g of calcium chloride, stir at 200 rpm for 20 min, and neutralize the pH to neutral with 0.5 mol / L sodium bicarbonate aqueous solution to obtain a modified carrier.

[0050] Comparative Example 1

[0051] The preparation method of a high ammonia nitrogen wastewater treatment reagent is basically the same as that of Example 1, and the only difference is that: the preparation method of the modified carrier is different.

[0052] The preparation method of the modified carrier is as follows:

[0053] S1. Add 10 g of acetonitrile and 10 g of acetic acid to 500 g of water, stir and mix at 200 rpm for 20 min, then add 2 g of chitosan, stir at 400 rpm for 2 h to obtain a chitosan solution; add 2 g of 3-hydroxy-4-nitrobenzoic acid to 20 g of acetonitrile, then add 2.5 g of (2-chloroethoxy) cyclopropane and 1.5 g of N-acryloxysuccinimide, stir at 200 rpm for 30 min, then add it to the chitosan solution, stir at 300 rpm at 30 °C for 15 h, and precipitate with 200 g of acetone to obtain a chitosan derivative;

[0054] S2. Add the chitosan derivative prepared in step S1 to 100 g of 1 wt% acetic acid aqueous solution, add 50 g of 1 mol / L oxalyl dihydrazide aqueous solution, stir at 200 rpm for 10 min, add 0.2 g of zinc powder, stir at 200 rpm at 30 °C for half an hour, filter and collect the solution, then drop 1 mol / L NaOH aqueous solution to adjust the pH to neutral to obtain modified chitosan;

[0055] S3. Add 0.1 g of montmorillonite to 20 g of water, ultrasonically oscillate at 400 W for 10 min to obtain a suspension. Add the suspension and 1.5 g of polyethyleneimine to 80 g of 1 mol / L sodium hydroxide aqueous solution, stir at 200 rpm at 50 °C for 40 min to obtain mixture A; then add 0.5 g of the modified chitosan prepared in step S2 to 30 g of 0.5 wt% acetic acid aqueous solution to obtain a modified chitosan solution; slowly drip the modified chitosan solution into mixture A at a dripping rate of 0.2 mL / min, then add 10 g of 25 wt% isovaleraldehyde propylene glycol acetal aqueous solution, stir at 200 rpm at 50 °C for 6 h, then filter and collect the solid at 50 °C, and dry for 24 h to obtain a composite material;

[0056] S4. Add 5 g of the composite material prepared in step S3 to 100 g of 1 wt% acetic acid aqueous solution, then add 2 g of calcium chloride, stir at 200 rpm for 20 min, and neutralize the pH to neutral with 0.5 mol / L sodium bicarbonate aqueous solution to obtain a modified carrier.

[0057] The preparation method of the nutrient is the same as that in Example 1.

[0058] Comparative Example 2

[0059] The preparation method of a high ammonia-nitrogen wastewater treatment reagent is basically the same as that in Example 1, and the only difference is that: the preparation method of the modified carrier is different.

[0060] The preparation method of the modified carrier is as follows:

[0061] S1. Add 10 g of acetonitrile and 10 g of acetic acid to 500 g of water, stir and mix at 200 rpm for 20 min, then add 2 g of chitosan, stir at 400 rpm for 2 h to obtain a chitosan solution; add 2 g of 3,4-dihydroxy-5-nitrobenzoic acid to 20 g of acetonitrile, then add 2.5 g of epichlorohydrin and 1.5 g of N-acryloxysuccinimide, stir at 200 rpm for 30 min, then add it to the chitosan solution, stir at 300 rpm at 30 °C for 15 h, and precipitate with 200 g of acetone to obtain a chitosan derivative;

[0062] S2. Add the chitosan derivative prepared in step S1 to 100 g of 1 wt% acetic acid aqueous solution, add 50 g of 1 mol / L oxalyl dihydrazide aqueous solution, stir at 200 rpm for 10 min, add 0.2 g of zinc powder, stir at 200 rpm at 30 °C for half an hour, filter and collect the solution, and then drip 1 mol / L NaOH aqueous solution to adjust the pH to neutral to obtain modified chitosan;

[0063] S3. Add 0.1 g of montmorillonite to 20 g of water, and ultrasonically oscillate at 400 W for 10 min to obtain a suspension. Add the suspension and 1.5 g of polyethyleneimine to 80 g of 1 mol / L sodium hydroxide aqueous solution, and stir at 200 rpm at 50 °C for 40 min to obtain mixture A; then add 0.5 g of the modified chitosan prepared in step S2 to 30 g of 0.5 wt% acetic acid aqueous solution to obtain a modified chitosan solution; slowly drop the modified chitosan solution into mixture A at a dropping rate of 0.2 mL / min, then add 10 g of 25 wt% isovaleraldehyde propylene glycol acetal aqueous solution, stir at 200 rpm at 50 °C for 6 h, then filter and collect the solid at 50 °C, and dry for 24 h to obtain a composite material;

[0064] S4. Add 5 g of the composite material prepared in step S3 to 100 g of 1 wt% acetic acid aqueous solution, then add 2 g of calcium chloride, stir at 200 rpm for 20 min, and neutralize with 0.5 mol / L sodium bicarbonate aqueous solution to a neutral pH to obtain a modified carrier.

[0065] The preparation method of the nutrient is the same as that in Example 1.

[0066] Comparative Example 3

[0067] The preparation method of a high ammonia-nitrogen wastewater treatment reagent is basically the same as that in Example 1, and the only difference is that: the preparation method of the modified carrier is different.

[0068] The preparation method of the modified carrier is as follows:

[0069] S1. Add 10 g of acetonitrile and 10 g of acetic acid to 500 g of water, stir and mix at 200 rpm for 20 min, then add 2 g of chitosan, and stir at 400 rpm for 2 h to obtain a chitosan solution; add 2 g of 3,4-dihydroxy-5-nitrobenzoic acid to 20 g of acetonitrile, then add 2.5 g of (2-chloroethoxy) cyclopropane and 1.5 g of N-acryloxysuccinimide, stir at 200 rpm for 30 min, then add to the chitosan solution, stir at 300 rpm at 30 °C for 15 h, and precipitate with 200 g of acetone to obtain a chitosan derivative;

[0070] S2. Add the chitosan derivative prepared in step S1 to 100 g of 1 wt% acetic acid aqueous solution, add 50 g of 1 mol / L oxalyl dihydrazide aqueous solution, stir at 200 rpm for 10 min, add 0.2 g of zinc powder, stir at 200 rpm at 30 °C for half an hour, filter and collect the solution, and then drop 1 mol / L NaOH aqueous solution to adjust the pH to neutral to obtain modified chitosan;

[0071] S3. Add the modified chitosan prepared in step S2 of 5 g to 100 g of 1 wt% aqueous acetic acid solution, then add 2 g of calcium chloride, stir at 200 rpm for 20 min, and neutralize the pH to neutral with 0.5 mol / L aqueous sodium bicarbonate solution to obtain a modified carrier.

[0072] The preparation method of the nutrient is the same as that in Example 1.

[0073] Comparative Example 4

[0074] The preparation method of a high ammonia-nitrogen wastewater treatment reagent is basically the same as that in Example 1, and the only difference is that: the preparation method of the modified carrier is different.

[0075] The preparation method of the modified carrier is as follows:

[0076] S1. Add 10 g of acetonitrile and 10 g of acetic acid to 500 g of water, stir and mix at 200 rpm for 20 min, then add 2 g of chitosan, stir at 400 rpm for 2 h to obtain a chitosan solution; add 2 g of 3-hydroxy-4-nitrobenzoic acid to 20 g of acetonitrile, then add 2.5 g of epichlorohydrin and 1.5 g of N-acryloxysuccinimide, stir at 200 rpm for 30 min, then add it to the chitosan solution, stir at 300 rpm at 30 °C for 15 h, and add 200 g of acetone to precipitate to obtain a chitosan derivative;

[0077] S2. Add the chitosan derivative prepared in step S1 to 100 g of 1 wt% aqueous acetic acid solution, add 50 g of 1 mol / L aqueous oxalyl dihydrazide solution, stir at 200 rpm for 10 min, add 0.2 g of zinc powder, stir at 200 rpm at 30 °C for half an hour, filter and collect the solution, and then dropwise add 1 mol / L aqueous NaOH solution to adjust the pH to neutral to obtain modified chitosan;

[0078] S3. Add 5 g of the modified chitosan prepared in step S2 to 100 g of 1 wt% aqueous acetic acid solution, then add 2 g of calcium chloride, stir at 200 rpm for 20 min, and neutralize the pH to neutral with 0.5 mol / L aqueous sodium bicarbonate solution to obtain a modified carrier.

[0079] The preparation method of the nutrient is the same as that in Example 1.

[0080] Comparative Example 5

[0081] The preparation method of a high ammonia-nitrogen wastewater treatment reagent is as follows:

[0082] Add 8 g of D-sodium glucuronate to 50 g of water, stir at 200 rpm for 20 min, add 10 g of compound bacteria, stir at 50 rpm for 30 min, then put 50 g of chitosan and 100 g of nutrients into a constant temperature incubator after stirring at 100 rpm for 30 min, aerate and culture at 30 °C, and keep the dissolved oxygen content at 3 mg / L. Replace half of the volume of nutrients every day to ensure that the microorganisms have sufficient nutrients. After culturing for 45 d, take out, rinse with physiological saline, and obtain a high ammonia nitrogen wastewater treatment reagent.

[0083] The preparation method of the nutrient substance is the same as that in Example 1.

[0084] Test Example 1

[0085] Ammonia nitrogen and COD absorption test

[0086] Let the water sample at the end of the aerobic tank stand for 30 min, measure ammonia nitrogen and COD, then separate the mud and water, and store the supernatant and activated sludge separately.

[0087] 1. Take 4 L of supernatant, add 8 mL of high ammonia nitrogen wastewater treatment reagent, aerate for 72 h, stand for 30 minutes, take 10 mL of supernatant, filter, and measure ammonia nitrogen and COD.

[0088] 2. Stir for 24 h, stand for 30 minutes, take 10 mL of supernatant, filter, and measure ammonia nitrogen and COD.

[0089] 3. Aerate for 24 h, stand for 30 minutes, take 10 mL of supernatant, filter, and measure ammonia nitrogen and COD.. The test results are shown in Table 1.

[0090] Table 1 Ammonia nitrogen and COD absorption test results

[0091]

[0092] Test Example 2

[0093] Chemical stability determination

[0094] Prepare acidic solutions with pH values of 2, 4, and 6 with hydrochloric acid, and prepare alkaline solutions with pH values of 8, 10, 12, and 14 with sodium hydroxide aqueous solution. Take 5 g of the high ammonia nitrogen wastewater treatment reagent prepared by the present invention and place it in the above solutions with different pH values. After soaking for 2 weeks, take it out and measure the mass loss of the carrier before and after soaking. The test results are shown in Table 2.

[0095] Table 2 Chemical stability test results

[0096]

[0097] Example 1 of the present invention has the best ammonia nitrogen and COD absorption effects and chemical stability. The possible reason is that in Example 1 of the present invention, the high ammonia nitrogen wastewater treatment reagent is prepared by adding sodium D-glucuronate to water and stirring, then adding composite bacteria and stirring, and then adding a modified carrier and nutrients and stirring, and then putting it into a constant temperature incubator for aeration culture. After cultivation, it is taken out and rinsed clean to obtain the high ammonia nitrogen wastewater treatment reagent. The modified carrier is prepared by adding acetonitrile and acetic acid to water and stirring to mix to obtain a solution, and then adding chitosan to the solution and stirring to obtain a chitosan solution; adding 3,4-dihydroxy-5-nitrobenzoic acid to acetonitrile, then adding (2-chloroethoxy) cyclopropane and N-acryloxysuccinimide and stirring, and then adding it to the chitosan solution and stirring, and adding acetone to precipitate to obtain a chitosan derivative; adding the chitosan derivative to an acetic acid aqueous solution, adding an oxalic acid dihydrazide aqueous solution and stirring, adding zinc powder and stirring, filtering and collecting the solution, and adjusting the pH to neutral to obtain modified chitosan; adding montmorillonite to water and ultrasonically oscillating to obtain a suspension, adding the suspension and polyethyleneimine to an aqueous sodium hydroxide solution and stirring at high temperature to obtain a mixture A, and then adding the modified chitosan to an acetic acid aqueous solution to obtain a chitosan solution; slowly dropping the chitosan solution into the mixture A, then adding an isovaleraldehyde propylene glycol acetal aqueous solution and stirring at high temperature, and then filtering and collecting the solid and drying to obtain a composite material; adding the composite material to an acetic acid aqueous solution, then adding calcium chloride and stirring, and adjusting the pH to neutral to obtain the modified carrier.

[0098] When comparing Example 1 with Comparative Example 1, according to the preparation method of the modified carrier described, 3,4-dihydroxy-5-nitrobenzoic acid is used as a precursor substance for the derivative. Compared with using 3-hydroxy-4-nitrobenzoic acid, the 3,4-dihydroxy group in 3,4-dihydroxy-5-nitrobenzoic acid has more functional chemical reaction sites relative to the 3-hydroxy group in 3-hydroxy-4-nitrobenzoic acid. These additional hydroxyl groups may increase the active sites on the surface of the modified carrier, thereby improving the adsorption capacity for pollutants such as ammonia nitrogen and COD. And the 3,4-dihydroxy group in 3,4-dihydroxy-5-nitrobenzoic acid may form a more stable bonding with the base material of the modified carrier, enhancing the chemical stability of the composite material. This strengthened bonding can improve the durability and anti-solubility of the modified carrier and extend its service life in the wastewater treatment process.

[0099] Compared with Comparative Example 2, in Example 1, (2-chloroethoxy)cyclopropane was used as a reactant. In contrast, in Comparative Example 2, epichlorohydrin was used. The chloroethoxy group in (2-chloroethoxy)cyclopropane has the activity of nucleophilic substitution reaction. This activity may enable it to combine with other functional groups on the surface of the modified carrier to form stronger chemical bonds, thereby enhancing the stability and durability of the carrier. (2-chloroethoxy)cyclopropane may have a higher reaction rate and more complete chemical modification, thus improving the adsorption performance and stability of the carrier. (2-chloroethoxy)cyclopropane and epichlorohydrin have different functional groups. The chloroethoxy group may introduce additional functional chemical reaction sites, thereby providing more surface active sites and enhancing the adsorption and catalytic degradation capabilities of the carrier for pollutants such as ammonia nitrogen and COD.

[0100] Compared with Comparative Example 3, in Example 1, a composite material was formed by mixing a chitosan derivative with montmorillonite and polyethyleneimine. This composite material may have a larger specific surface area and adsorption active sites, thus improving the adsorption capacity for pollutants such as ammonia nitrogen and COD. An aqueous solution of isovaleraldehyde propylene glycol acetal was used for the reaction. This reaction may introduce more functional chemical groups, enhance the surface active sites of the modified carrier, and thus increase the adsorption and catalytic degradation capabilities for pollutants.

[0101] Compared with Comparative Example 5, in Example 1, a modified carrier was used instead of chitosan. The modified carrier may have a larger specific surface area and adsorption active sites compared to chitosan, and the number of amino groups on the modified carrier is more than that of chitosan. It can combine more fully with sodium D-glucuronate through the reaction between amino and carboxyl groups, making the immobilized bacteria balls more stable and enhancing their pH resistance. Therefore, it has a higher adsorption capacity when treating high-ammonia-nitrogen wastewater. The modified carrier may introduce more adsorption sites and active groups through surface functionalization modification or composite material preparation methods, thereby improving the adsorption effect on ammonia nitrogen. The surface properties and structural characteristics of the modified carrier may contribute to the attachment and growth of microorganisms. The modified carrier may provide a more suitable microbial growth environment, such as suitable surface roughness, pore structure, and hydrophilic / hydrophobic properties, thereby promoting the bioattachment and biosorption processes of halophilic microorganisms. Thus, the adsorption capacity for pollutants such as ammonia nitrogen and COD is improved.

Claims

1. A reagent for treating high ammonia nitrogen wastewater, characterized in that, It contains the following components in parts by weight: 8 - 12 parts of compound bacteria, 5 - 10 parts of D - sodium glucuronate, 40 - 60 parts of modified carrier, and 80 - 120 parts of nutrients; The preparation method of the said modified carrier is as follows, in parts by weight: S1. Add 8 - 12 parts of acetonitrile and 8 - 12 parts of acetic acid into 400 - 600 parts of water, stir - mix at 100 - 500 rpm for 10 - 50 min, then add 1 - 3 parts of chitosan, stir at 100 - 500 rpm for 1 - 3 h to obtain a chitosan solution; Add 1 - 3 parts of benzoic acid compounds into 10 - 30 parts of acetonitrile, then add 2 - 3 parts of propane compounds and 1 - 2 parts of N - acryloxysuccinimide, stir at 100 - 500 rpm for 10 - 50 min, then add it into the chitosan solution, stir at 100 - 500 rpm at 25 - 35 °C for 10 - 20 h, add 150 - 300 parts of acetone for precipitation to obtain chitosan derivatives; S2. Add the chitosan derivatives prepared in step S1 into 80 - 120 parts of 0.5 - 2 wt% acetic acid aqueous solution, add 40 - 60 parts of 0.5 - 2 mol / L oxalyl dihydrazide aqueous solution, stir at 100 - 500 rpm for 5 - 15 min, add 0.1 - 0.3 parts of zinc powder, stir at 100 - 500 rpm at 25 - 35 °C for half an hour, filter and collect the solution, then dropwise add 0.5 - 2 mol / L NaOH aqueous solution to adjust the pH to neutral to obtain modified chitosan; S3. Add 4 - 6 parts of the modified chitosan prepared in step S2 into 80 - 120 parts of 0.5 - 2 wt% acetic acid aqueous solution, then add 1 - 3 parts of calcium chloride, stir at 100 - 300 rpm for 10 - 30 min, neutralize the pH to neutral with 0.4 - 0.6 mol / L sodium bicarbonate aqueous solution to obtain the modified carrier; The benzoic acid compound is one of 3,4 - dihydroxy - 5 - nitrobenzoic acid and 3 - hydroxy - 4 - nitrobenzoic acid.

2. A reagent for treating high ammonia nitrogen wastewater, characterized in that, It contains the following components in parts by weight: 8 - 12 parts of compound bacteria, 5 - 10 parts of D - sodium glucuronate, 40 - 60 parts of modified carrier, and 80 - 120 parts of nutrients; The preparation method of the said modified carrier is as follows, in parts by weight: S1. Add 8 - 12 parts of acetonitrile and 8 - 12 parts of acetic acid into 400 - 600 parts of water, stir - mix at 100 - 500 rpm for 10 - 50 min, then add 1 - 3 parts of chitosan, stir at 100 - 500 rpm for 1 - 3 h to obtain a chitosan solution; Add 1 - 3 parts of benzoic acid compounds into 10 - 30 parts of acetonitrile, then add 2 - 3 parts of propane compounds and 1 - 2 parts of N - acryloxysuccinimide, stir at 100 - 500 rpm for 10 - 50 min, then add it into the chitosan solution, stir at 100 - 500 rpm at 25 - 35 °C for 10 - 20 h, add 150 - 300 parts of acetone for precipitation to obtain chitosan derivatives; S2. Add the chitosan derivative prepared in step S1 to 80 - 120 parts of 0.5 - 2 wt% acetic acid aqueous solution, add 40 - 60 parts of 0.5 - 2 mol / L oxalyl dihydrazide aqueous solution, stir at 100 - 500 rpm for 5 - 15 min, add 0.1 - 0.3 parts of zinc powder, stir at 100 - 500 rpm at 25 - 35 °C for half an hour, filter to collect the solution, and then dropwise add 0.5 - 2 mol / L NaOH aqueous solution to adjust the pH to neutral to obtain the modified chitosan; S3. Add 0.05 - 0.2 parts of montmorillonite to 15 - 25 parts of water, ultrasonically oscillate at 200 - 500 W for 5 - 20 min to obtain a suspension. Add the suspension and 1 - 3 parts of polyethyleneimine to 50 - 100 parts of 0.5 - 2 mol / L sodium hydroxide aqueous solution, stir at 100 - 300 rpm at 40 - 60 °C for 10 - 60 min to obtain mixture A; then add 0.4 - 0.6 parts of the modified chitosan prepared in step S2 to 20 - 40 parts of 0.4 - 0.6 wt% acetic acid aqueous solution to obtain a modified chitosan solution; Slowly drop the modified chitosan solution into mixture A at a dropping rate of 0.1 - 0.3 mL / min, then add 8 - 12 parts of 10 - 28 wt% isovaleraldehyde propylene glycol acetal aqueous solution, stir at 100 - 500 rpm at 40 - 60 °C for 4 - 8 h, then filter and collect the solid at 40 - 60 °C, and dry for 10 - 30 h to obtain the composite material; S4. Add 4 - 6 parts of the composite material prepared in step S3 to 80 - 120 parts of 0.5 - 2 wt% acetic acid aqueous solution, add 1 - 3 parts of calcium chloride, stir at 100 - 300 rpm for 10 - 30 min, and neutralize the pH to neutral with 0.4 - 0.6 mol / L sodium bicarbonate aqueous solution to obtain the modified carrier; The benzoic acid compound is one of 3,4 - dihydroxy - 5 - nitrobenzoic acid and 3 - hydroxy - 4 - nitrobenzoic acid.

3. A high ammonia nitrogen wastewater treatment reagent according to claim 1 or 2, characterized in that The nutrient substance is composed of the following components at the following concentrations: glucose 8 - 12 g / L, peptone 8 - 12 g / L, sodium chloride 15 - 25 g / L, lauryl borate 0.01 - 0.03 g / L, magnesium chloride 8 - 9 g / L, sodium sulfate 2 - 4 g / L, calcium chloride 1 - 2 g / L, sodium silicate 3 - 5 mg / L, yeast extract 0.5 - 2 g / L, potassium chloride 0.4 - 0.6 g / L, ammonium nitrate 1 - 2 mg / L, sodium bicarbonate 0.1 - 0.2 g / L, disodium hydrogen phosphate 6 - 8 mg / L, ferric sulfate 0.01 - 0.02 g / L, potassium bromide 0.04 - 0.06 g / L, strontium dichloride 0.01 - 0.03 g / L, and sodium fluoride 1 - 3 mg / L, with the balance being water. Adjust the final pH of the culture medium to 6.5 - 7.5 with a buffer reagent, and autoclave the culture medium at 100 - 125 °C for 10 - 50 min to obtain the nutrient substance.

4. The high-ammonia-nitrogen wastewater treatment reagent according to claim 3, characterized in that, The buffer reagent is a boric acid aqueous solution with a concentration of 0.1 - 0.3 mg / L or a sodium bicarbonate aqueous solution with a concentration of 40 - 60 mg / L.

5. A high ammonia-nitrogen wastewater treatment reagent according to claim 1 or 2, characterized in that, The propane compound is one of (2-chloroethoxy) cyclopropane and epichlorohydrin.

6. A method for preparing a high ammonia nitrogen wastewater treatment reagent as described in any one of claims 1 to 5, characterized in that, The preparation method is as follows: Weigh each raw material by weight. Add sodium D-glucuronate to water with a mass 5 - 8 times that of sodium D-glucuronate, stir at 100 - 500 rpm for 10 - 30 min, add the composite bacteria, stir at 10 - 80 rpm for 10 - 50 min, then put the modified carrier and nutrients into a constant temperature incubator after stirring at 50 - 200 rpm for 10 - 50 min, aerobically cultivate at 25 - 35 °C, and keep the dissolved oxygen content at 1 - 5 mg / L. Replace half of the volume of nutrients every day to ensure that the microorganisms have sufficient nutrition. After culturing for 30 - 60 d, take it out, rinse it thoroughly with physiological saline to obtain the high ammonia-nitrogen wastewater treatment reagent.

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