阅读说明：本技术 一种颗粒菌种及其制备方法和在污水生化处理中的应用 (Granular strain, preparation method thereof and application thereof in biochemical treatment of sewage ) 是由 朱成成 董磊 陈萌萌 刘兹敏 于 2021-10-14 设计创作，主要内容包括：本发明涉及一种颗粒菌种及其制备方法和在污水生化处理中的应用,属于污水处理技术领域。本发明的颗粒菌种包括有机粘结剂、生长有菌种的载体和疏孔剂。具体制备方法为以生长有菌种的载体、有机粘合剂、有机酸、疏孔剂为原材料,通过完全混合、搅拌、造粒、烘干等工艺流程,获得性能稳定的颗粒菌种。本发明的颗粒菌种具有良好的污水处理效果,可大幅度提高生化效率,适用于多种水体的生化处理系统。本发明的颗粒菌种制作工艺简单,并且可以用于各类污水的治理,能够满足现阶段大部分污水生化的需求。(The invention relates to a granular strain, a preparation method thereof and application thereof in biochemical treatment of sewage, belonging to the technical field of sewage treatment. The granular strain of the invention comprises an organic binder, a carrier with the strain growing thereon and a pore-dredging agent. The preparation method comprises the steps of taking a carrier with strains growing, an organic adhesive, an organic acid and a pore-dredging agent as raw materials, and obtaining the granular strains with stable performance through the technological processes of complete mixing, stirring, granulation, drying and the like. The granular strain has good sewage treatment effect, can greatly improve the biochemical efficiency, and is suitable for biochemical treatment systems of various water bodies. The granular strain has simple preparation process, can be used for treating various kinds of sewage, and can meet the biochemical requirement of most of the sewage at the present stage.)

1. The granular strain is characterized by comprising the following substances in parts by weight:

1-2.5 parts by weight of organic binder;

30-50 parts by weight of a carrier with strains;

1-2.5 parts of a pore-thinning agent.

2. Granular bacterial species according to claim 1,

the diameter of the granular strain is selected from 5-10mm, preferably 5-8 mm.

3. Granular bacterial species according to claim 1,

the organic binder is selected from natural organic high molecular binder, preferably one or a combination of chitosan and chitin.

4. Granular strain according to claim 1, characterized in that the porphobizing agent is selected from one or more of the group consisting of carbonates, bicarbonates, percarbonates, preferably one or more of potassium carbonate, sodium bicarbonate, sodium carbonate, potassium bicarbonate, sodium percarbonate or potassium percarbonate.

5. Granular bacterial species according to claim 1,

in the carrier with the strain growing, the carrier has a porous microspherical structure;

the strains comprise nitrifying bacteria and denitrifying bacteria;

the mass ratio of the strain to the carrier is 1: 4-1: 5.

6. a method of producing granular bacterial species according to any one of claims 1 to 5, characterized in that it comprises the following steps:

(1) according to the proportion, after the organic acid is added into the water, the organic binder is slowly added to prepare a suspension;

(2) fully dissolving the suspension to obtain a mixed solution;

(3) adding the carrier with the strain and the pore-dredging agent into the mixed solution, and uniformly stirring to obtain a solid mixture;

(4) and (4) granulating and drying the solid mixture to obtain the granular strain.

7. The method for preparing granular bacterial seeds of claim 6, wherein,

in the preparation of the granular strain, the adding amount of each raw material comprises the following components in parts by weight:

8. the method for preparing granular bacterial seeds of claim 6, wherein,

the organic acid is selected from small molecule volatile acid, and is preferably one or a combination of propionic acid and glacial acetic acid.

9. The method for preparing granular bacterial seeds of claim 6, wherein,

in the step (2),

stirring the mixture under the heating condition of 40-70 ℃ to completely dissolve the suspension;

in the step (4), the step (c),

the diameter of the granules prepared by granulation is selected from 5-10 mm; more preferably from 5 to 8 mm;

the drying conditions are as follows: drying at 27-37 deg.C for more than 12 hr.

10. Use of a granular bacterial species according to any one of claims 1 to 5 in the biochemical treatment of wastewater.

Technical Field

The invention relates to the technical field of sewage treatment, in particular to a granular strain, a preparation method thereof and application thereof in biochemical sewage treatment.

Technical Field

In China, water resources are in short supply, the problem of water pollution is more and more serious along with the development of social economy, the discharge amount of waste water is high, and the water environment is to be improved urgently. At present, the widely applied biochemical treatment technology, namely the activated sludge process, is born before 100 years, and the principle is that nutrient components in a water body are consumed in the process of growth of microorganisms in sewage, and meanwhile, thalli are spontaneously aggregated to form sludge colonies, and the growth effect of the colonies is necessary for the activated sludge process. However, the spontaneously formed bacterial sludge mass is large and uncontrollable, so the method has low treatment efficiency and limited system load and cannot treat high-concentration wastewater.

Biochemical sludge is generally disposed of by incineration, which consumes a lot of energy, and landfill, which requires expensive landfill costs, which is not sustainable. Aiming at the defects of the traditional activated sludge process, various solutions are proposed for solving the problems that the composite material disclosed in the Chinese patent CN107362769A has a porous lamellar microspherical structure, can effectively treat high-concentration organic pollutants after being compounded with microorganisms, quickly reduces the COD (chemical oxygen demand) of sewage, can effectively remove the contents of ammonia nitrogen, total nitrogen and total phosphorus, and reduces the yield of biochemical treatment sludge. However, the particle size of the microspheres is small, the water inflow in the early stage is large, when the flow rate is high, the microspheres are easily taken away by water power and are not easily intercepted, the loss rate of the microspheres is high, and the material loss rate is high.

The granular sludge technology of sewage is discovered for the first time in an anaerobic system in the last 80 th century, and researchers discover that the granular sludge has stronger organic wastewater treatment capacity, can be applied to various fields of alcohol wastewater, starch wastewater, beer wastewater and the like, and has the advantages of good settling property, compact granular structure, strong toxicity resistance and the like. However, the content of organic matters which are easily oxidized by organisms in the sewage is high, and the yield coefficient of microorganisms in the granular sludge is high, so that the granular sludge is decomposed. In addition, the gradient of dissolved oxygen in the particles is uneven, so that the inside of the particle sludge is anaerobic, and the particle sludge is disintegrated, so that the particle sludge technology is difficult to exert the advantages of the particle sludge technology, is limited in development, and cannot be fully applied to actual engineering. Therefore, the research and development of a stable and efficient biochemical granular strain has very important significance.

Disclosure of Invention

Aiming at the existing restriction limitation, the invention provides a granular strain, a preparation method thereof and application thereof in biochemical treatment of sewage. The granular strain can stay for a long time in the sewage treatment process, has strong impact resistance, and is not easy to break into small granules in a short time; the sludge is not easy to loosen and expand, and is not easy to be brought out by water flow, the material loss rate is low, the activation time is short, the biochemical efficiency is high, and the sewage treatment effect is good.

In order to achieve the purpose, the invention adopts the following technical scheme:

one purpose of the invention is to provide a granular strain, which comprises the following substances in parts by weight:

1-2.5 parts by weight of organic binder; preferably 1 to 2 parts by weight;

30-50 parts by weight of carrier with strain growing thereon, preferably 30-40 parts by weight;

1-2.5 parts of a pore-thinning agent; preferably 1-2 parts by weight.

The organic binder is distributed among carriers with strains and is used for binding the carriers with the strains.

Preferably, the first and second liquid crystal materials are,

the diameter of the granular strain is selected from 5-10mm, preferably 5-8 mm.

Preferably, the first and second liquid crystal materials are,

the organic binder is selected from natural organic high molecular binders, and more preferably from one or a combination of chitosan and chitin. The organic binder must be a polymer which can be dissolved in an acid solution but is insoluble in water, and if some polymers such as carrageenan in the prior art are used as the binder to prepare balls, the balls can be disintegrated in 4 hours when entering water. The method adopts volatile organic acid, the acid is volatilized in the drying process of the spheres, the chitosan and the chitin are separated out after volatilization, on one hand, the organic high molecular binder plays a role in adhesion, on the other hand, the organic high molecular binder and the chitin are also frameworks after drying, and therefore, the finally prepared granular strain is porous microspheres. Most preferably, the chitosan is white or grey white semitransparent flaky solid, is easy to dissolve in dilute acid but insoluble in water, is sticky, is non-toxic and harmless, and has biodegradability.

Preferably, the first and second liquid crystal materials are,

the pore-thinning agent is selected from one or more of carbonate, bicarbonate and percarbonate, preferably one or more of potassium carbonate, sodium bicarbonate, sodium carbonate, potassium bicarbonate, sodium percarbonate or potassium percarbonate.

Preferably, the first and second liquid crystal materials are,

in the carrier with the strain growing, the carrier has a porous microspherical structure; in the present invention, a conventional growth support such as silica, activated carbon, etc., more preferably a composite material having a microspherical structure with a porous lamellar as disclosed in CN107362769A, may be used as the support;

the strain comprises nitrifying bacteria and denitrifying bacteria which are common engineering bacteria, preferably, the mass ratio of the nitrifying bacteria to the denitrifying bacteria is 1: 1-2; nitrifying bacteria in the present invention include nitrifying bacteria and nitrifying bacteria. The denitrifying bacteria mainly comprise strains of pseudomonas and bacillus.

The mass ratio of the strain to the carrier is 1: 4-1: 5.

another object of the present invention is to provide a method for preparing a granular strain of the first object of the present invention, comprising the steps of:

(1) adding organic acid into water, and slowly adding the organic binder to prepare a suspension;

(2) fully dissolving the suspension to obtain a mixed solution;

(3) adding the carrier with the strain and the pore-dredging agent into the mixed solution, and uniformly stirring to obtain a pasty solid mixture;

(4) and (4) granulating and drying the solid mixture to obtain the granular strain.

Preferably, the first and second liquid crystal materials are,

in the preparation of the granular strain, the adding amount of each raw material comprises the following components in parts by weight:

preferably, the first and second liquid crystal materials are,

the organic acid is selected from small molecule volatile acid, more preferably from one or a combination including but not limited to propionic acid and glacial acetic acid;

preferably, the first and second liquid crystal materials are,

in the step (2),

the full dissolution refers to complete dissolution under the condition of heating and stirring; the full dissolution refers to complete dissolution under the condition of heating and stirring; in the invention, the condition of full dissolution is not specially required, so that full dissolution can be realized.

Preferably, under the heating condition of 40-70 ℃, stirring at a speed of more than 300r/min to completely dissolve the suspension;

in the step (4), the step (c),

the diameter of the granules prepared by granulation is selected from 5-10 mm; more preferably from 5 to 8 mm;

the drying conditions are as follows: drying at 27-37 deg.C for more than 12 hr.

In the granular strain material, the natural organic high molecular adhesive can only be dissolved in dilute acid, and the organic acid is easy to volatilize, so that the acidic components and water used after the prepared granular strain is dried can volatilize, the stable structure of the granular strain in water can be ensured, the impact resistance is strong, and the granular strain is not easy to loosen; in the sewage treatment, the obtained granular strains can only slowly peel off layer by layer from outside to inside in water, and the duration is greatly prolonged. Meanwhile, the high molecular materials used for preparing the particles can be used as a slow-release carbon source to strengthen the nitrogen and phosphorus removal effect of the strains.

The granular strain of the invention takes a carrier with strains growing thereon, a natural organic high molecular adhesive, a pore-dredging agent and some organic acids as raw materials, and obtains the granular strain with stable performance through the process flows of complete mixing, stirring, granulation, drying and the like.

The granular strain has good sewage treatment effect, can greatly improve the biochemical efficiency, and is suitable for biochemical treatment systems of various water bodies. The natural polymer organic binder is environment-friendly, and other toxic and harmful substances cannot be introduced.

The third purpose of the invention is to provide the application of the granular strain in the biochemical treatment of sewage.

Preferably, the first and second liquid crystal materials are,

the adding amount of the granular strains is 1/200-1/100 of the mass of the sewage;

more preferably, it is a mixture of more preferably,

directly adding the granular strain into the sewage to be biochemically treated according to the addition amount of 1/200-1/100 wt%, and adjusting the ratio of C: n: the mass ratio of the P elements is 100: 5: 1, the pH value is 6.4-7.4, and aeration is provided according to actual requirements.

The sewage is common municipal sewage, high-concentration organic wastewater, high-salinity wastewater, other wastewater which is difficult to treat, such as papermaking wastewater, alcohol wastewater, desulfurization wastewater, degreasing and phosphorization wastewater, nickel plating wastewater, piggery wastewater, various breeding sewage, emulsified oil wastewater, ammonia nitrogen wastewater, organic silicon wastewater, pulping and papermaking wastewater, pharmaceutical industry wastewater, pesticide or garbage percolate and the like.

Practice proves that the total amount of the biochemical sludge treated by the method is reduced by 20-30%.

The granular strain can be applied to various sewage biochemical treatments. For example, the following types of sewage treatment are applicable:

the granular strain can be used for common municipal sewage, can be domesticated quickly, reduces the retention time, reduces the generation of excess sludge, and has a COD removal rate of over 80 percent.

The granular strain disclosed by the invention has a compact nuclear structure and has high diffusion prevention performance on external particles, so that the whole strain has high tolerance capability on toxic substances. Can effectively remove toxic substances such as 2-chlorophenol, 2, 4-dinitrotoluene and the like in the synthetic wastewater.

The granular strain can be used for high salinity wastewater, and has excellent biological nutrient removal capability and biodegradation performance of toxic or stubborn pollutants. Can effectively prevent the problems of destabilization and decomposition of the granular sludge and the like caused by improper salt content in the solution.

In addition, the method is also suitable for other waste water which is difficult to treat. For example, paper-making wastewater, alcohol wastewater, desulfurization wastewater treatment, degreasing and phosphorization wastewater, nickel plating wastewater treatment, pig farm wastewater treatment, treatment of various breeding wastewater, emulsified oil wastewater, ammonia nitrogen wastewater, organosilicon wastewater treatment, pulping and paper-making wastewater, pharmaceutical industry wastewater, pesticide or garbage leachate and the like.

Compared with the prior art, the invention has the beneficial effects that:

1. the granular strain can stably exist in water for at least half a year in the water treatment process, has strong impact resistance, is not easy to loosen and generate sludge bulking phenomenon, has short activation time and high biochemical efficiency, and simultaneously, the added chemical agent does not influence the biological activity of the strain and only needs a small amount of supplement for follow-up.

2. The method has the characteristics of cost saving, high treatment efficiency and environmental protection, and the granular strains have good settling property and have high-efficiency removal effect on water pollutants.

3. The granular strain is simple in preparation process, can be used for treating various kinds of sewage, and can meet the biochemical requirements of most of the sewage at the present stage.

4. After the granular strain is put into a water body, due to the structural characteristics of the granular strain, dissolved oxygen is different at different parts of sludge, and most of oxygen is consumed by an active cell layer living outside the granular strain, so that oxygen is not available at the core of the granular strain, aerobic conditions and anoxic conditions required by denitrification in sewage can be realized in the granular sludge, and the granular strain has a loose porous structure, so that gaseous substances generated inside the granular strain under anaerobic conditions can be quickly dissipated and discharged through a pore passage, and the problem that the granular sludge is disintegrated due to anaerobic property inside the granular sludge cannot be caused. Therefore, the granular strains can realize good biological nitrogen and phosphorus removal effects and keep good organic matter removal rate and self stability.

5. The natural organic polymer adhesive added in the granular strain is environment-friendly and has wide material sources.

6. In the prior art, a carrier with strains growing is used as a core, chitosan is used as an embedding agent and the like, and is solidified to form a shell, so that particle strains similar to a core-shell structure are formed, and only the outermost layer can play a role when the particle strains are actually used, so that the contact area with sewage is small; the granular strains are microspheres with porous structures on the surfaces, so that the strains which can actually participate in biochemical reaction and the contact area are greatly increased.

Drawings

FIG. 1 is a photograph of a granular seed product of the present invention;

FIG. 2 is a photograph of the present invention after long-term use in sewage.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below. It is to be understood that the description herein is only illustrative of the present invention and is not intended to limit the scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, and the terms used herein in the specification of the present invention are for the purpose of describing particular embodiments only and are not intended to limit the present invention. The reagents and instruments used in the present invention are commercially available, and the characterization means involved can be referred to the description in the prior art, which is not repeated herein.

For a further understanding of the present invention, reference will now be made in detail to the preferred embodiments of the present invention.

The materials used in the examples and comparative examples of the present invention are, if specifically mentioned, all those which are conventionally commercially available products or which can be prepared by a conventional method.

The support was prepared using the conditions disclosed in CN107362769A example 1.

The nitrifying bacteria and denitrifying bacteria in the carrier with the strain are common engineering bacteria, and the nitrifying bacteria comprise nitrite bacteria and nitrate bacteria. The denitrifying bacteria mainly comprise strains of pseudomonas and bacillus.

Example 1

Adding 0.5 weight part of organic acid propionic acid into 50 weight parts of deionized water, slowly adding 1 weight part of natural organic polymer adhesive chitosan, heating and stirring at 70 ℃ until the chitosan is dissolved to prepare a solution with the mass concentration of 2%, wherein the stirring time is about 4 hours, and the stirring speed is 300 r/min. After cooling, slowly adding 30 parts by weight of carrier (mass ratio of nitrobacteria to denitrifying bacteria is 1: 2, mass ratio of bacteria to carrier is 1: 4) with bacteria growth and 1 part by weight of sodium carbonate, fully stirring to paste, pouring into a granulator to obtain granular bacteria with the diameter of about 5mm, and then blowing at 37 ℃ for constant temperature drying for 12 hours to obtain granular bacteria for sewage biochemistry, wherein the specific product is shown in figure 1.

And (3) comparing biochemical effects:

taking the granular strain prepared in the embodiment 1 of the invention and granular sludge sold in the market (purchased from Jiangxi water, environmental protection and science Co., Ltd.), adding the strain according to the mass ratio of 1/100, taking common domestic sewage as inlet water, wherein the Chemical Oxygen Demand (COD) in the sewage is 541mg/L, and ammonia Nitrogen (NH)₃-N) 35.9mg/L, Total Phosphorus (TP) 0.584mg/L, Total Nitrogen (TN) 81.46mg/L, using a cyclic alternating operation of aeration for 4 h-standing under anoxic conditions for 4 h-aeration for 4h, operating for 5 days.

The average NH of the treated granular sludge on the market is measured₃The N removal rate is 84.2 percent, the total nitrogen removal rate reaches 71.5 percent, the phosphorus removal efficiency reaches 61 percent, the organic matter removal rate of the inlet water reaches 92 percent, and meanwhile, the granular sludge is partially disintegrated.

Measurement of particles prepared in example 1 of the present inventionAverage NH after biochemical treatment of granular strains₃The N removal rate reaches 95.8 percent, the total nitrogen removal rate reaches 85.4 percent, the phosphorus removal efficiency reaches 73 percent, the removal rate of influent organic matters reaches 95 percent, and meanwhile, the particle size of the granular strains is kept about 5 mm; after 5 days of biochemical process, the external dimension of the granular strain is consistent with that of the granular strain when the granular strain is put into the reactor, the external dimension of the granular strain is not greatly lost, the disintegration rate is 0.5 percent, and the strain loss rate is 0.35 percent; more than 50% of the commercial granular sludge is disintegrated, and the strain loss rate is about 10%. Under the sewage treatment conditions of example 1, the granular strain prepared in example 1 was placed in sewage for half a year, the disintegration rate was 0.5%, and most of the granular strain remained relatively stable, as shown in fig. 2.

Example 2

Adding 0.5 weight part of organic acid glacial acetic acid into 50 weight parts of deionized water, slowly adding 1.5 weight parts of natural organic polymer adhesive chitin, heating and stirring at 70 ℃ until the natural organic polymer adhesive chitin is dissolved to prepare a solution with the mass concentration of 3%, wherein the stirring time is about 8 hours, and the stirring speed is 300 r/min. After cooling, slowly adding 40 parts by weight of carrier (mass ratio of nitrobacteria to denitrifying bacteria is 1: 2, mass ratio of bacteria to carrier is 1: 5) with bacteria growing and 2.5 parts by weight of sodium percarbonate, fully stirring to be pasty, pouring into a granulator to obtain granular bacteria about 8mm, and then blowing at 37 ℃ for constant temperature drying for 12 hours to obtain the granular bacteria for sewage biochemistry.

Adding the strains into the granular strains prepared in the embodiment 2 according to the mass ratio of 1/100, taking the common domestic sewage as the inlet water, wherein the COD in the sewage is 541mg/L, NH₃N is 35.9mg/L, TP and 0.584mg/L, TN is 81.46mg/L, and the operation time is 5 days by adopting a cyclic alternating operation mode of aeration for 4 hours, standing for 4 hours and aeration for 4 hours under an anoxic condition.

The average NH of the granular strains prepared in example 2 of the present invention after biochemical treatment was measured₃The N removal rate reaches 96.8 percent, the total nitrogen removal rate reaches 82.1 percent, the phosphorus removal efficiency reaches 71.9 percent, the removal rate of influent organic matters reaches 93 percent, and meanwhile, the particle size of the granular strains is kept about 8 mm; the external dimension of the granular strain is consistent with that of the strain when the granular strain is put into the device after 5 days of biochemical process, the disintegration rate is 0.2 percent, and the strain loss rate is0.16 percent; more than 50% of the commercial granular sludge is disintegrated, and the strain loss rate is about 10%.

Example 3

Adding 0.8 weight part of organic acid propionic acid into 50 weight parts of deionized water, slowly adding 2 weight parts of natural organic polymer adhesive chitosan, heating and stirring at 70 ℃ until the chitosan is dissolved to prepare a solution with the weight concentration of 4%, wherein the stirring time is about 7 hours, and the stirring speed is 400 r/min. Slowly adding 30 parts by weight of carrier (mass ratio of nitrobacteria to denitrifying bacteria is 1: 2, mass ratio of bacteria to carrier is 1: 4) with strains growing and 2 parts by weight of sodium bicarbonate, fully stirring to paste, pouring into a granulator to obtain granular strains about 8mm, and then blowing at 37 ℃ for constant temperature drying for 12 hours to obtain the granular strains for sewage biochemistry. And (3) comparing biochemical effects:

taking the granular strains prepared in the embodiment 3 of the invention, adding the strains according to the mass ratio of 1/100, taking the common domestic sewage as the inlet water, and the COD is 541mg/L, NH₃N is 35.9mg/L, TP and 0.584mg/L, TN is 81.46mg/L, and the operation time is 5 days by adopting a cyclic alternating operation mode of aeration for 4 hours, standing for 4 hours and aeration for 4 hours under an anoxic condition.

The average NH of the granular bacterial strains prepared in the example 3 of the present invention after biochemical treatment was measured₃The N removal rate reaches 89.6 percent, the total nitrogen removal rate reaches 75.1 percent, the phosphorus removal efficiency reaches 69.1 percent, the removal rate of the organic matters in the inlet water reaches 94.9 percent, and meanwhile, the particle size of most granular strains is kept about 8 mm; after 5 days of biochemical process, the external dimension of the granular strain is consistent with that of the granular strain when the granular strain is put into the reactor, the external dimension of the granular strain is not greatly lost, the disintegration rate is 0.1 percent, and the strain loss rate is 0.1 percent; more than 50% of the commercial granular sludge is disintegrated, and the strain loss rate is about 10%.

Example 4

Adding 1 weight part of organic acid propionic acid into 50 weight parts of deionized water, slowly adding 2.5 weight parts of natural organic polymer adhesive chitosan, heating and stirring at 70 ℃ until the chitosan is dissolved, wherein the stirring time is about 7 hours, and the stirring speed is 400 r/min. Slowly adding 50 parts by weight of carrier (mass ratio of nitrobacteria to denitrifying bacteria is 1: 2, mass ratio of bacteria to carrier is 1: 4) with strains growing and 2.5 parts by weight of sodium carbonate, fully stirring to paste, pouring into a granulator to obtain granular strains about 8mm, and then blowing at 37 ℃ for constant temperature drying for 12 hours to obtain the granular strains for sewage biochemistry. And (3) comparing biochemical effects:

taking the granular strains prepared in the embodiment 4 of the invention, adding the strains according to the mass ratio of 1/100, taking the common domestic sewage as the inlet water, and the COD is 541mg/L, NH₃N is 35.9mg/L, TP and 0.584mg/L, TN is 81.46mg/L, and the operation time is 5 days by adopting a cyclic alternating operation mode of aeration for 4 hours, standing for 4 hours and aeration for 4 hours under an anoxic condition.

The average NH of the granular bacterial strains prepared in the example 4 of the present invention after biochemical treatment was measured₃The N removal rate reaches 90.6 percent, the total nitrogen removal rate reaches 79.4 percent, the phosphorus removal efficiency reaches 71.5 percent, the removal rate of the organic matters in the inlet water reaches 94.7 percent, and meanwhile, the particle size of most granular strains is kept about 8 mm; after 5 days of biochemical process, the external dimension of the granular strain is consistent with that of the granular strain when the granular strain is put into the reactor, the external dimension of the granular strain is not greatly lost, the disintegration rate is 0.25 percent, and the strain loss rate is 0.1 percent; more than 50% of the commercial granular sludge is disintegrated, and the strain loss rate is about 10%.

Comparative example 1

It is essentially the same as the preparation of example 1, except that: 3.5 parts by weight of natural organic polymer adhesive chitosan and 5 parts by weight of pore-thinning agent are added, and the mixture is stirred to be pasty under the same condition and then poured into a granulator to obtain a stable granulation effect, because too much pore-thinning agent causes too many pores to form the granules.

Comparative example 2

It is essentially the same as the preparation of example 1, except that: adding 0.2 weight part of natural organic polymer adhesive chitosan and 0.1 weight part of pore-dredging agent, stirring to paste under the same condition, pouring into a granulator to obtain granular strains with the diameter of about 10mm, and then carrying out blast air constant-temperature drying at 27 ℃ for 12 hours to obtain granular strains for sewage biochemistry, wherein the surfaces of the obtained strains have no obvious pores.

The granular strains of the comparative example 2 are taken and added with the strains according to the mass ratio of 1/100 so as toThe common domestic sewage is inlet water, and the COD is 541mg/L, NH₃N is 35.9mg/L, TP and 0.584mg/L, TN is 81.46mg/L, and the operation time is 5 days by adopting a cyclic alternating operation mode of aeration for 4 hours, standing for 4 hours and aeration for 4 hours under an anoxic condition.

The average NH after biochemical treatment of the granular bacterial species of comparative example 2 was measured₃The N removal rate is only 79.4 percent, the total nitrogen removal rate reaches 73.5 percent, the phosphorus removal efficiency reaches 62.9 percent, the removal rate of the organic matters in the inlet water reaches 90.9 percent, meanwhile, partial granular strains also have the decomposition rate of about 10 percent, and the strain loss rate is about 9 percent.

Comparative example 3

It contained only the vector of example 1 with the growing seed.

Adding the strains into the granular strains in comparative example 3 according to the mass ratio of 1/100, taking the common domestic sewage as inlet water, and ensuring that the COD is 541mg/L, NH₃N is 35.9mg/L, TP and 0.584mg/L, TN is 81.46mg/L, and the operation time is 5 days by adopting a cyclic alternating operation mode of aeration for 4 hours, standing for 4 hours and aeration for 4 hours under an anoxic condition.

The average NH after biochemical treatment of the granular bacterial species of comparative example 3 was measured₃The N removal rate is only 80.5 percent, the total nitrogen removal rate is 74.1 percent, the phosphorus removal efficiency is 63.1 percent, the removal rate of the organic matters in the inlet water is 91.8 percent, meanwhile, partial granular strains are decomposed by about 10 percent, and the strain loss rate is about 15 percent.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents or improvements made within the spirit and principle of the present invention should be included in the scope of the present invention.