CN115286118B - A method for treating sewage with a low-temperature resistant denitrification and phosphorus removal compound microbial agent - Google Patents

Abstract

The invention discloses a method for treating sewage by using a low-temperature-resistant denitrification and dephosphorization composite microbial agent, and relates to a method for treating sewage by using a microbial agent. The nitrifying bacteria and the denitrifying bacteria in the low-temperature-resistant denitrification and dephosphorization composite microbial agent are matched with each other to remove total nitrogen in the sewage, and the phosphorus accumulating bacteria are used for removing total phosphorus in the sewage, so that the aims of synergistic interaction and synchronous denitrification and dephosphorization can be achieved, and the effect of removing nitrogen and phosphorus in the sewage is obviously higher than that of a single strain in a low-temperature environment. Each strain in the low-temperature-resistant denitrification and dephosphorization composite microbial agent is separated from winter sludge and river sediment in northern cold areas, and is an environment-friendly microorganism. When in use, the water is directly put in without complex engineering technology, is convenient to operate and has no secondary pollution, and has good application prospect.

Description

A method for treating sewage with a low-temperature resistant denitrification and phosphorus removal compound microbial agent

Technical field

The present invention relates to a method for treating sewage, in particular to a method for treating sewage with a low-temperature resistant denitrification and phosphorus removal compound microbial agent.

Background technique

With the rapid development of social economy and the continuous improvement of living standards, the continuous discharge of large amounts of urban sewage containing nitrogen and phosphorus pollutants has caused excessive pollution loads in water bodies, causing eutrophication and black and odorous phenomena in many rivers, lakes and other water bodies, which has further affected the environment. pose serious threats to the ecological environment and human health. Therefore, the search for safe, efficient, simple and easy wastewater nitrogen and phosphorus removal technology has become a research hotspot.

At present, the nitrogen and phosphorus removal technologies for wastewater at home and abroad are mainly divided into physical methods (adsorption, electrodialysis), chemical methods (flocculation precipitation, ion exchange) and biological methods. Among them, biological methods often use microbial inoculants to remove nitrogen and phosphorus. Microbial nitrogen and phosphorus removal technology has the advantages of simple operation, low operating cost, good treatment effect, and no secondary pollution. It is the most widely used and most promising method among many wastewater nitrogen and phosphorus removal technologies. However, the temperature of urban sewage in winter in cold areas in northern my country can drop to 8°C to 15°C, or even lower than 5°C. Most microorganisms with the function of denitrification and phosphorus are mesophilic bacteria. The optimal growth temperature is 20°C ~ 37°C. Generally, the treatment effect is good at 20°C ~ 25°C. However, the biology of microorganisms in low temperature environments below 15°C The activity and metabolic efficiency dropped sharply, which seriously hindered the denitrification and phosphorus removal of functional bacteria, resulting in poor denitrification and phosphorus removal of domestic sewage in low temperature environments. Therefore, the development of microbial agents that grow well under low temperature conditions and can efficiently remove nitrogen and phosphorus from sewage has very important social and economic benefits.

At present, researchers have proposed that low-temperature microbial inoculants can improve the problems of poor cell membrane fluidity, poor permeability, and low enzyme activity under low-temperature conditions, thereby improving the removal effect of nitrogen and phosphorus in sewage under low-temperature environments in winter. However, most relevant domestic research is still in its infancy. Most of the single low-temperature bacterial strains used are often difficult to achieve the purification treatment effect of urban sewage. However, the development and construction of low-temperature-resistant composite microbial inoculants is still relatively weak, and in water pollution Cases of successful applications of governance are rarely reported.

Contents of the invention

The object of the present invention is to provide a method for treating sewage with a low-temperature resistant denitrification and phosphorus removal composite microbial agent. This method is intended to solve the problem of low microbial activity under low temperature conditions in winter and poor microbial denitrification and phosphorus removal in urban sewage. The present invention The strains using compound microbial inoculants have strong synergistic metabolic capabilities, can metabolize and reproduce in a lower temperature environment, and effectively denitrify and remove phosphorus from sewage. Secondary pollution.

The purpose of the present invention is achieved through the following technical solutions:

A method for treating sewage with a low-temperature resistant denitrification and phosphorus removal composite microbial agent, which method includes the following processes:

First, prepare a low-temperature-tolerant denitrification and phosphorus removal composite microbial agent, including the following preparation steps:

(1) Preparation of heterotrophic nitrifying compound bacterial solution: Use an inoculating loop to pick 3 to 4 rings of psychrotolerant Pseudomonas herbivores from the slant solid culture medium and inoculate it into the heterotrophic nitrifying bacteria culture medium, and inoculate it at a temperature of 6 to 15°C. Shake and culture in a full-temperature shaking incubator with a rotation speed of 120 to 170 rpm for 24 to 72 hours to obtain a cold-tolerant Pseudomonas herbiaceus seed liquid (the number of viable bacteria is 1×10 ⁷ to 2×10 ⁹ colonies/ml); Use an inoculating loop to pick 3 to 4 rings of cold-tolerant sludge pseudomonas from the slant solid culture medium and inoculate them into the heterotrophic nitrifying bacteria culture medium, and inoculate them in a full-temperature shaking incubator with a temperature of 6 to 15°C and a rotation speed of 120 to 170 rpm. Culture with medium shaking for 24 to 72 hours to obtain a cold-tolerant Pseudomonas sludge seed liquid (the number of viable bacteria is 1×10 ⁷ to 2×10 ⁹ colonies/ml); The monospora seed solution is simultaneously inoculated into the heterotrophic nitrifying bacteria culture medium according to the inoculum volume ratio (1 to 10): (1 to 10) and the total inoculum volume of 5% to 20%, and the temperature is 6 to 15°C and the rotation speed is 120 Shake and culture in a full-temperature shaking incubator at ~170 rpm for 48 to 96 hours to obtain a heterotrophic nitrifying compound bacterial solution; the total number of viable bacteria in the heterotrophic nitrifying compound bacterial solution is 1×10 ⁸ to 5×10 ⁹ colonies Count/ml;

(2) Preparation of aerobic denitrifying compound bacterial solution: Use an inoculating loop to pick 3 to 4 rings of cold-tolerant Pseudomonas verona from the slant solid culture medium and inoculate it into the aerobic denitrifying bacteria culture medium at a temperature of 6 to Shake and culture for 24 to 72 hours in a full-temperature shaking incubator at 15°C and 120 to 170 rpm to obtain a cold-tolerant Pseudomonas verona seed liquid (the number of viable bacteria is 1×10 ⁷ to 2×10 ⁹ colonies) several/ml); use an inoculation loop to pick 3 to 4 rings of Pseudomonas fluorescens from the slant solid culture medium and inoculate it into the aerobic denitrifying bacteria culture medium, at a temperature of 6 to 15°C and a rotation speed of 120 to 170 rpm. Shake and culture in a full-temperature shaking incubator for 24 to 72 hours to obtain a fluorescent Pseudomonas seed liquid (the number of viable bacteria is 1×10 ⁷ to 2×10 ⁹ colonies/ml); add the cold-tolerant Pseudomonas verona The bacterial seed liquid and Pseudomonas fluorescens are inoculated into the aerobic denitrifying bacteria culture medium according to the inoculum volume ratio (1 to 10): (1 to 10), and the total inoculum volume is 5% to 20%, and the temperature is 6 to 15 °C and a full-temperature oscillating incubator with a rotation speed of 120 to 170 rpm and cultured with shaking for 48 to 96 hours to obtain a good-trophic denitrifying compound bacterial solution; the total number of viable bacteria in the heterotrophic nitrifying compound bacterial solution is 1×10 ⁸ ~ 5×10 ⁹ colonies/ml;

(3) Preparation of phosphate-polymer compound bacterial solution: Use an inoculating loop to pick 3 to 4 rings of Arthrobacter antarctica from the slant solid culture medium and inoculate it into the phosphorus-polymer culture medium, and inoculate it at a temperature of 6 to 15°C and a rotation speed of 120 to 170 rpm. /min in a full-temperature shaking incubator for 23 to 72 hours to obtain Arthrobacter antarctica (the number of viable bacteria is 1×10 ⁷ to 2×10 ⁹ colonies/ml). Use an inoculation loop to pick 3 to 4 rings of Halocrystalline Psychrobacterium from the slant solid culture medium and inoculate it into the polyphosphate culture medium, and shake it in a full-temperature shaking incubator with a temperature of 6 to 15°C and a rotation speed of 120 to 170 rpm. Cultivate for 24 to 72 hours to obtain a halocrystalline Psychrobacter seed liquid (the number of viable bacteria is 1×10 ⁷ to 2×10 ⁹ colonies/ml). Inoculate Arthrobacter antarctica seed liquid and Halocrystalline Psychrobacter seed liquid into the phosphorus-accumulating bacteria culture medium according to the inoculum volume ratio (1 to 10): (1 to 10) and the total inoculum volume of 5% to 20%. Shake and culture in a full-temperature oscillating incubator at 6 to 15°C and a rotation speed of 120 to 170 rpm for 48 to 96 hours to obtain a polyphosphorus compound bacterial solution; the total number of viable bacteria in the polyphosphorus compound bacterial solution is 1×10 ⁸ ~ 5×10 ⁹ colonies/ml;

(4) Preparation of low-temperature-tolerant denitrification and phosphorus removal compound microbial inoculants: Mix the heterotrophic nitrification compound bacterial solution, aerobic denitrification compound bacterial solution and phosphorus-polymerizing compound bacterial solution according to the volume ratio of (1~10): (1~ 10): (1-20) are mixed in a ratio to make a low-temperature-resistant denitrification and phosphorus removal composite microbial agent; the total number of viable bacteria in the composite microbial agent is not less than 1×10 ¹⁰ colonies/ml;

The above-mentioned low-temperature-resistant denitrification and phosphorus-removal composite microbial inoculants are used in low-temperature biological sewage treatment. The steps are as follows:

Add a low-temperature denitrification and phosphorus removal compound microbial agent at a dosage of 2×10 ² to 5×10 ² colonies/cm2 to the urban sewage to be treated, and aerate it at an aeration rate of 1.0 to 3.5 cubic meters/hour. 24 to 48 hours, let it sit for 20 to 30 minutes, then filter out the water.

The method for treating sewage with a low-temperature-tolerant denitrification and phosphorus-removal compound microbial agent, the preparation of the heterotrophic nitrification compound bacterial solution, the cold-tolerant Pseudomonas herbaceae and the cold-tolerant Pseudomonas sludge are both from the sewage treatment plant The activated sludge in the sedimentation tank was identified as Pseudomonas poae and Pseudomonas peli through 16SrDNA sequence analysis.

The method for treating sewage with a low-temperature resistant denitrification and phosphorus removal compound microbial agent, the preparation of the heterotrophic nitrifying compound bacterial solution, and the composition of the heterotrophic nitrifying bacteria culture medium is: 1.0 to 5.0 g/L sodium citrate, 0.2～1.0g/L ammonium sulfate, 0.3～1.5g/L potassium dihydrogen phosphate, 0.1～1.0g/L magnesium sulfate heptahydrate, 0.1～1.0g/L sodium chloride, 0.01～0.1g/L sulfuric acid heptahydrate Ferrous iron, 0.01 to 0.1 g/L anhydrous calcium chloride. Use 10% HCl and NaOH to adjust the pH of the heterotrophic nitrifying bacteria culture medium to 6.5 to 7.5.

The method for treating sewage with a low-temperature-tolerant denitrification and phosphorus-removal compound microbial agent. In the preparation of the heterotrophic nitrification compound bacterial solution, the cold-resistant Pseudomonas verona and Pseudomonas fluorescens are both frozen river water. The sediment was identified as Pseudomonas veronii and Pseudomonas fluorescens through 16SrDNA sequence analysis.

The method for treating sewage with a low-temperature-resistant denitrifying and phosphorus-removing compound microbial agent, the preparation of the heterotrophic nitrifying compound bacterial solution, and the aerobic denitrifying bacteria medium composition is: 1.0 to 5.0 g/L sodium citrate , 0.2~2.0g/L sodium nitrate, 0.3~1.5g/L potassium dihydrogen phosphate, 0.1~1.0g/L magnesium sulfate heptahydrate, 0.1~1.0g/L sodium chloride, 0.01~0.1g/L heptahydrate Ferrous sulfate, 0.01-0.1 g/L anhydrous calcium chloride; use 10% HCl and NaOH to adjust the pH of the aerobic denitrifying bacteria culture medium to 6.5-7.5.

The method for treating sewage with a low-temperature-resistant denitrification and phosphorus removal composite microbial agent uses a QHZ-98A full-temperature oscillating incubator for culturing the microbial liquid.

In the method for treating sewage with a low-temperature resistant denitrification and phosphorus removal composite microbial agent, the high-pressure steam sterilization adopts an SN210C vertical pressure steam sterilizer.

In the method of treating sewage with a low-temperature resistant denitrification and phosphorus removal composite microbial agent, the culture medium is sterilized by high-pressure steam, and the treatment conditions are a temperature of 121°C and a pressure of 0.105 MPa, maintained for 20 to 30 minutes.

The invention has the following significant technical advantages:

1. The low-temperature denitrification and phosphorus removal compound microbial agent involved in the present invention can grow, metabolize and reproduce normally in a lower temperature environment (6-15°C), and can effectively denitrify and remove sewage.

2. Each strain in the low-temperature-tolerant denitrification and phosphorus removal composite microbial inoculant of the present invention is isolated from winter sludge and river bottom mud in cold northern regions, and they are all environment-friendly microorganisms. It is put in directly when used, does not require complex engineering processes, is easy to operate and has no secondary pollution, and has good application prospects.

3. The nitrifying bacteria and denitrifying bacteria in the low-temperature-tolerant denitrification and phosphorus removal composite microbial inoculant of the present invention cooperate with each other to remove total nitrogen in the sewage, and the phosphorus-accumulating bacteria remove the total phosphorus in the sewage, so synergy can be achieved , for the purpose of simultaneous nitrogen and phosphorus removal, the removal effect of nitrogen and phosphorus in sewage under low temperature environment is significantly higher than that of a single strain.

Description of the drawings

Figure 1 is an electron microscope photograph of Pseudomonas phlebaceae of the present invention;

Figure 2 is an electron microscope photograph of Pseudomonas sludge of the present invention;

Figure 3 is an electron microscope photograph of Pseudomonas verona of the present invention;

Figure 4 is an electron microscope photograph of Pseudomonas fluorescens of the present invention;

Figure 5 is an electron microscope photograph of Arthrobacter antarctica of the present invention;

Figure 6 is an electron microscope photograph of Halocrystalline Psychrobacterium of the present invention.

Detailed ways

The present invention will be described in detail below with reference to the embodiments shown in the drawings.

The invention first prepares a low-temperature-resistant denitrification and phosphorus-removal composite microbial agent. The total number of viable bacteria of the composite microbial agent is not less than 1×10 ¹⁰ colonies/ml, including low-temperature-resistant heterotrophic nitrifying composite bacteria, good low-temperature resistance, and Oxygen-denitrifying complex bacteria and low-temperature-tolerant phosphorus-polymerizing complex bacteria. Among them, the low-temperature-tolerant heterotrophic nitrifying complex bacteria include Pseudomonas poae and Pseudomonas peli . The total number of viable bacteria of the low-temperature-tolerant heterotrophic nitrifying complex bacteria is 1×10 ⁸ to 5 ×10 ⁹ colonies/ml; the low-temperature-resistant aerobic denitrifying complex bacteria include Pseudomonas veronii and Pseudomonas fluorescens . The total number of low-temperature-resistant aerobic denitrifying complex bacteria The number of viable bacteria is 1×10 ⁸ to 5×10 ⁹ colonies/ml; the low-temperature-tolerant phosphate-polymerizing complex bacteria include Arthrobacter antarcticus and Psychrobacter cryohalolentis . The low-temperature-tolerant phosphate-polymerizing complex bacteria The total viable bacterial count is 1×10 ⁸ to 5×10 ⁹ colonies/ml.

Experiments have proven that the formula of the composite microbial agent of the present invention is reasonable. There is no antagonism between the bacterial strains. The six bacterial strains have synergistic effects after compounding. They have significant effects on nitrogen and phosphorus removal from urban sewage under low temperature conditions and have good application prospects.

Pseudomonas poae , Pseudomonas peli , Pseudomonas veronii , Pseudomonas fluorescens, Arthrobacter antarcticus and Psychrobacter cryohalolentis was isolated from the activated sludge of the secondary sedimentation tank of a sewage treatment plant in Shenyang City, Liaoning Province and the frozen bottom sludge of river water in winter. It was identified as a known existing strain and is in major strain collection libraries. All are preserved.

The preparation method of the low-temperature-resistant denitrification and phosphorus removal composite microbial inoculant of the present invention includes the following steps:

(1) Preparation of heterotrophic nitrifying compound bacterial solution: Use an inoculating loop to pick 3 to 4 rings of psychrotolerant Pseudomonas herbivores from the slant solid culture medium and inoculate it into the heterotrophic nitrifying bacteria culture medium, and inoculate it at a temperature of 6 to 15°C. Shake and culture in a full-temperature shaking incubator with a rotation speed of 120 to 170 rpm for 24 to 72 hours to obtain a cold-tolerant Pseudomonas herbiaceus seed liquid (the number of viable bacteria is 1×10 ⁷ to 2×10 ⁹ colonies/ml). Use an inoculating loop to pick 3 to 4 rings of cold-tolerant sludge pseudomonas from the slant solid culture medium and inoculate them into the heterotrophic nitrifying bacteria culture medium, and inoculate them in a full-temperature shaking incubator with a temperature of 6 to 15°C and a rotation speed of 120 to 170 rpm. Culture with medium shaking for 24 to 72 hours to obtain a cold-tolerant Pseudomonas sludge seed liquid (the number of viable bacteria is 1×10 ⁷ to 2×10 ⁹ colonies/ml). Inoculate the cold-tolerant Pseudomonas pseudomonas seed liquid and the cold-tolerant Pseudomonas slushie seed liquid simultaneously into the heterotrophic nitrifying bacteria according to the inoculum volume ratio (1 to 10): (1 to 10), with a total inoculum volume of 5% to 20%. In the culture medium, shake and culture it in a full-temperature shaking incubator with a temperature of 6 to 15°C and a rotation speed of 120 to 170 rpm for 48 to 96 hours to obtain a heterotrophic nitrifying compound bacterial solution. The total viable bacterial count of the heterotrophic nitrifying compound bacterial solution is 1×10 ⁸ to 5×10 ⁹ bacterial colonies/ml.

Among them, psychrotolerant Pseudomonas herba and psychrotolerant Pseudomonas sludge were both isolated from the activated sludge of the secondary sedimentation tank of the southern sewage treatment plant in Shenyang City, Liaoning Province in January 2021. After 16SrDNA sequence analysis, they were respectively identified as Pseudomonas herba. bacteria ( Pseudomonas poae ) and Pseudomonas peli ( Pseudomonas peli ).

The composition of the heterotrophic nitrifying bacteria culture medium is: 1.0-5.0 g/L sodium citrate, 0.2-1.0 g/L ammonium sulfate, 0.3-1.5 g/L potassium dihydrogen phosphate, 0.1-1.0 g/L magnesium sulfate heptahydrate, 0.1~1.0 g/L sodium chloride, 0.01~0.1 g/L ferrous sulfate heptahydrate, 0.01~0.1 g/L anhydrous calcium chloride. Use 10% HCl and NaOH to adjust the pH of the heterotrophic nitrifying bacteria culture medium to 6.5 to 7.5.

(2) Preparation of aerobic denitrifying compound bacterial solution: Use an inoculating loop to pick 3 to 4 rings of cold-tolerant Pseudomonas verona from the slant solid culture medium and inoculate it into the aerobic denitrifying bacteria culture medium at a temperature of 6 to Shake and culture for 24 to 72 hours in a full-temperature shaking incubator at 15°C and 120 to 170 rpm to obtain a cold-tolerant Pseudomonas verona seed liquid (the number of viable bacteria is 1×10 ⁷ to 2×10 ⁹ colonies) number/ml). Use an inoculating loop to pick 3 to 4 rings of Pseudomonas fluorescens from the slant solid culture medium and inoculate it into the aerobic denitrifying bacteria culture medium, and culture it at full temperature shaking at a temperature of 6 to 15°C and a rotation speed of 120 to 170 rpm. Incubate in the box with shaking for 24 to 72 hours to obtain Pseudomonas fluorescens seed liquid (the number of viable bacteria is 1×10 ⁷ to 2×10 ⁹ colonies/ml). Inoculate the cold-tolerant Pseudomonas verona seed solution and Pseudomonas fluorescens into the aerobic denitrifying bacteria culture according to the inoculum volume ratio (1 to 10): (1 to 10) and the total inoculum volume of 5% to 20%. In the base, shake and culture it in a full-temperature oscillating incubator with a temperature of 6 to 15°C and a rotation speed of 120 to 170 rpm for 48 to 96 hours to obtain a good denitrifying compound bacterial solution. The total viable bacterial count of the heterotrophic nitrifying compound bacterial solution is 1×10 ⁸ to 5×10 ⁹ bacterial colonies/ml.

Among them, psychrotolerant Pseudomonas veronensis and Pseudomonas fluorescens were both isolated from the frozen sediment of the Beiyun River in Shenyang City, Liaoning Province in January 2021. They were respectively identified as Pseudomonas veronensis through 16SrDNA sequence analysis. ( Pseudomonas veronii ) and Pseudomonas fluorescens .

The composition of the aerobic denitrifying bacteria culture medium is: 1.0~5.0 g/L sodium citrate, 0.2~2.0 g/L sodium nitrate, 0.3~1.5 g/L potassium dihydrogen phosphate, 0.1~1.0 g/L magnesium sulfate heptahydrate , 0.1~1.0 g/L sodium chloride, 0.01~0.1 g/L ferrous sulfate heptahydrate, 0.01~0.1 g/L anhydrous calcium chloride. Use 10% HCl and NaOH to adjust the pH of the aerobic denitrifying bacteria culture medium to 6.5-7.5.

(3) Preparation of phosphate-polymer compound bacterial solution: Use an inoculating loop to pick 3 to 4 rings of Arthrobacter antarctica from the slant solid culture medium and inoculate it into the phosphorus-polymer culture medium, and inoculate it at a temperature of 6 to 15°C and a rotation speed of 120 to 170 rpm. /min in a full-temperature shaking incubator for 23 to 72 hours to obtain Arthrobacter antarctica (the number of viable bacteria is 1×10 ⁷ to 2×10 ⁹ colonies/ml). Use an inoculation loop to pick 3 to 4 rings of Halocrystalline Psychrobacterium from the slant solid culture medium and inoculate it into the polyphosphate culture medium, and shake it in a full-temperature shaking incubator with a temperature of 6 to 15°C and a rotation speed of 120 to 170 rpm. Cultivate for 24 to 72 hours to obtain a halocrystalline Psychrobacter seed liquid (the number of viable bacteria is 1×10 ⁷ to 2×10 ⁹ colonies/ml). Inoculate Arthrobacter antarctica seed liquid and Halocrystalline Psychrobacter seed liquid into the phosphorus-accumulating bacteria culture medium according to the inoculum volume ratio (1 to 10): (1 to 10) and the total inoculum volume of 5% to 20%. Shake and culture in a full-temperature oscillating incubator at 6 to 15°C and a rotation speed of 120 to 170 rpm for 48 to 96 hours to obtain a phosphorus-polysing compound bacterial solution. The total viable bacterial count of the polyphosphorus complex bacterial solution is 1×10 ⁸ to 5×10 ⁹ bacterial colonies/ml.

Among them, Arthrobacter antarcticus and Psychrobacter halocrystal were both isolated from the frozen sediment of the Beiyun River in Shenyang City, Liaoning Province in February 2021. After 16SrDNA sequence analysis, they were identified as Arthrobacter antarcticus ( Arthrobacter antarcticus ) and Psychrobacter halocrystal respectively. Psychrobacter cryohalolentis .

The composition of the phosphorus-accumulating bacteria culture medium is: 1.0~5.0 g/L sodium acetate, 0.1~2.0 g/L ammonium sulfate, 0.01~1.0 g/L dipotassium hydrogen phosphate, 0.05~0.2 g/L magnesium sulfate heptahydrate, 0.01~ 0.1 g/L calcium chloride, 7.0~9.0 g/L 4-hydroxyethylpiperazineethanesulfonic acid. Use 10% HCl and NaOH to adjust the pH of the culture medium to 6.5-7.5.

(4) Preparation of low-temperature-tolerant denitrification and phosphorus removal compound microbial inoculants: Mix the heterotrophic nitrification compound bacterial solution, aerobic denitrification compound bacterial solution and phosphorus-polysing compound bacterial solution according to the volume ratio of (1~10): (1~ 10): (1 ~ 20) mixed in the ratio to make a low-temperature resistant denitrification and phosphorus removal composite microbial inoculant. The total number of viable bacteria of the composite microbial agent is not less than 1×10 ¹⁰ colonies/ml.

The application process of the low-temperature-resistant denitrification and phosphorus removal composite microbial agent for treating sewage according to the invention:

Add a low-temperature denitrification and phosphorus removal compound microbial agent at a dosage of 2×10 ² to 5×10 ² colonies/cm2 to the urban sewage to be treated, and aerate it at an aeration rate of 1.0 to 3.5 cubic meters/hour. 24 to 48 hours, let it sit for 20 to 30 minutes, then filter out the water.

The technical solution of the present invention will be further described below through specific implementations.

Example 1:

(1) Preparation of heterotrophic nitrifying compound bacterial solution: Use an inoculating loop to pick 3 rings of cold-tolerant Pseudomonas herbii from the slant solid culture medium and inoculate it into the heterotrophic nitrifying culture medium. Shake and culture in a warm shaking incubator for 48 hours to obtain a cold-tolerant Pseudomonas herbiaceus seed liquid (the number of viable bacteria is 2×10 ⁷ colonies/ml). Use an inoculation loop to pick 3 rings of cold-tolerant sludge Pseudomonas from the slant solid culture medium and inoculate it into the heterotrophic nitrification medium. Shake and culture it in a full-temperature shaking incubator at 6°C and 150 rpm for 48 hours to obtain cold-tolerant Pseudomonas sludge seed liquid (the number of viable bacteria is 3×10 ⁷ colonies/ml). Inoculate the cold-tolerant Pseudomonas pseudomonas seed liquid and the cold-tolerant Pseudomonas sludge seed liquid simultaneously into the heterotrophic nitrifying bacteria culture medium at an inoculation volume ratio of 1:2 and a total inoculum volume of 15%, and inoculate them at 6°C and 150 rpm. The mixture was shaken and cultured in a full-temperature shaking incubator for 96 hours to obtain a heterotrophic nitrifying compound bacterial solution. The total viable bacterial count of the heterotrophic nitrifying compound bacterial solution is 1×10 ⁸ bacterial colonies/ml.

Among them, the composition of the heterotrophic nitrifying bacteria culture medium is: 2.5 g/L sodium citrate, 0.5 g/L ammonium sulfate, 0.3 g/L potassium dihydrogen phosphate, 0.1 g/L magnesium sulfate heptahydrate, 0.4 g/L chloride Sodium, 0.04 g/L ferrous sulfate heptahydrate, 0.03 g/L anhydrous calcium chloride. Use 10% HCl and NaOH to adjust the pH of the heterotrophic nitrifying bacteria culture medium to 7.0.

(2) Preparation of aerobic denitrifying compound bacterial solution: Use an inoculating loop to pick 3 rings of cold-tolerant Pseudomonas verona from the slant solid culture medium and inoculate it into the aerobic denitrifying bacteria culture medium, and inoculate it at 6°C and 150 Shake and culture in a full-temperature shaking incubator at 10 rpm for 48 hours to obtain a cold-tolerant Pseudomonas verona seed liquid (the number of viable bacteria is 4×10 ⁸ colonies/ml). Use an inoculating loop to pick 3 rings of Pseudomonas fluorescens from the slant solid culture medium and inoculate it into the aerobic denitrifying bacteria culture medium, and culture it in a full-temperature shaking incubator at 6°C and 150 rpm for 48 hours to obtain Pseudomonas fluorescens seed solution (the number of viable bacteria is 3×10 ⁷ colonies/ml). Inoculate the cold-tolerant Pseudomonas verona seed solution and Pseudomonas fluorescens into the aerobic denitrifying bacteria culture medium at an inoculation volume ratio of 2:1 and a total inoculum volume of 15%, and inoculate them at 6°C and 150 rpm. The culture was shaken and cultured in a full-temperature shaking incubator for 96 hours to obtain a good denitrifying compound bacterial solution. The total viable bacterial count of the heterotrophic nitrifying compound bacterial solution is 3×10 ⁸ bacterial colonies/ml.

The composition of the aerobic denitrifying bacteria culture medium is: 2.5 g/L sodium citrate, 1.5 g/L sodium nitrate, 0.3 g/L potassium dihydrogen phosphate, 0.1 g/L magnesium sulfate heptahydrate, 0.4 g/L sodium chloride , 0.04 g/L ferrous sulfate heptahydrate, 0.03 g/L anhydrous calcium chloride. Use 10% HCl and NaOH to adjust the pH of the aerobic denitrifying bacteria culture medium to 7.0.

(3) Preparation of phosphorus-polymer compound bacterial solution: Use an inoculating loop to pick 3 rings of Arthrobacter antarctica from the slant solid culture medium and inoculate it into the phosphorus-polymer culture medium, and place it in a full-temperature shaking incubator at 6°C and 150 rpm. Culture with medium shaking for 48 hours to obtain Arthrobacter antarctica (the number of viable bacteria is 3×10 ⁷ colonies/ml). Use an inoculation loop to pick 3 rings of Halocrystalline Psychrobacterium from the slant solid culture medium and inoculate it into the Phosphorus polyphosphate culture medium. Shake and culture it in a full-temperature shaking incubator at 6°C and 150 rpm for 48 hours to obtain the Halocrystalline Psychrophilus. Psychrobacter seed liquid (the number of viable bacteria is 3×10 ⁷ colonies/ml). Inoculate Arthrobacter antarcticus seed liquid and Halocrystalline Psychrobacter seed liquid into the polyphosphate culture medium at an inoculation volume ratio of 1:1 and a total inoculum volume of 10%, and culture at 6°C and 150 rpm at full temperature shaking. The culture was shaken in a box for 96 hours to obtain a phosphorus-polysing compound bacterial solution. The total viable bacterial count of the polyphosphorus compound bacterial solution is 2×10 ⁸ bacterial colonies/ml.

The composition of the culture medium for polyphosphate bacteria is: 3.5 g/L sodium acetate, 0.8 g/L ammonium sulfate, 0.02 g/L dipotassium hydrogen phosphate, 0.1 g/L magnesium sulfate heptahydrate, 0.02 g/L calcium chloride, 8.5 g /L 4-Hydroxyethylpiperazineethanesulfonic acid. Use 10% HCl and NaOH to adjust the pH of the culture medium to 7.0.

(4) Preparation of low-temperature denitrification and phosphorus removal compound microbial inoculants: Mix the heterotrophic nitrification compound bacterial solution, aerobic denitrification compound bacterial solution and phosphorus-polymerizing compound bacterial solution in a volume ratio of 3:3:5. That is, a low-temperature-resistant denitrification and phosphorus removal composite microbial agent is made. The total viable bacterial count of the composite microbial inoculant is 2×10 ¹⁰ bacterial colonies/ml.

Application of low-temperature-resistant denitrification and phosphorus-removal composite microbial inoculants in sewage: Use low-temperature-resistant denitrification and phosphorus-removal composite microbial inoculants to conduct domestic sewage treatment tests under low temperature conditions. Domestic sewage is taken from the sewage treatment center of a university campus. The water quality indicators are shown in Table 1.

Table 1 Domestic sewage quality indicators

The low-temperature denitrification and phosphorus removal composite microbial inoculant described in Example 1, Pseudomonas herba, Pseudomonas sludge, Pseudomonas verona, Pseudomonas fluorescens, Arthrobacter antarctica and salt crystals Psychrotrophic bacteria were inoculated into 1 liter of domestic sewage. The total inoculation amount of the composite microbial agent and the single bacteria were the same (both were 3×10 ² colonies/cm²), and at 8°C, 1.8 cubic meters After aeration for 24 hours at an aeration rate of Domestic sewage was used as a control to calculate the removal rates of ammonia nitrogen, nitrate nitrogen, total nitrogen, total phosphorus and COD. The results are shown in Table 2.

Table 2 Treatment effects of composite microbial agents and single strains on domestic sewage

The removal rates of ammonia nitrogen, nitrate nitrogen, total nitrogen, total phosphorus and COD in domestic sewage under low temperature conditions by the composite microbial agent described in Example 1 are 88.4%, 86.7%, 83.2%, 88.5% and 98.2% respectively. , the removal rate is significantly improved compared to a single strain. It can be seen that the composite microbial strains formed after compounding can synergistically promote growth and metabolism, effectively improving the removal efficiency of nitrogen and phosphorus in sewage.

Example 2:

(1) Preparation of heterotrophic nitrifying compound bacterial solution: Use an inoculating loop to pick 4 rings of cold-tolerant Pseudomonas herbii from the slant solid culture medium and inoculate it into the heterotrophic nitrifying bacteria culture medium, incubate at a temperature of 10°C and a rotation speed of 160 rpm The mixture was shaken and cultured for 48 hours in a full-temperature shaking incubator for 48 minutes to obtain a cold-tolerant Pseudomonas herbiaceus seed liquid (the number of viable bacteria was 2×10 ⁸ colonies/ml). Use an inoculating loop to pick 4 loops of cold-tolerant sludge pseudomonas from the slant solid culture medium and inoculate it into the heterotrophic nitrifying bacteria culture medium, and culture it in a full-temperature shaking incubator with a temperature of 10°C and a rotation speed of 160 rpm for 48 hours. , to obtain a cold-tolerant sludge Pseudomonas seed liquid (the number of viable bacteria is 4×10 ⁸ colonies/ml). Inoculate the cold-tolerant Pseudomonas grass seed liquid and the cold-tolerant Pseudomonas sludge seed liquid at the same time into the heterotrophic nitrifying bacteria culture medium at an inoculation volume ratio of 2:1 and a total inoculum volume of 15%, and inoculate them at a temperature of 10°C and a rotation speed of 160 The mixture was shaken and cultured in a full-temperature shaking incubator at 10 rpm for 72 hours to obtain a heterotrophic nitrifying compound bacterial solution. The total viable bacterial count of the heterotrophic nitrifying compound bacterial solution is 3×10 ⁹ bacterial colonies/ml.

Among them, the composition of the heterotrophic nitrifying bacteria culture medium is: 3.0 g/L sodium citrate, 0.8 g/L ammonium sulfate, 0.5 g/L potassium dihydrogen phosphate, 0.2 g/L magnesium sulfate heptahydrate, 0.1 g/L chloride Sodium, 0.03 g/L ferrous sulfate heptahydrate, 0.02 g/L anhydrous calcium chloride. Use 10% HCl and NaOH to adjust the pH of the heterotrophic nitrifying bacteria culture medium to 7.0.

(2) Preparation of aerobic denitrifying compound bacterial solution: Use an inoculating loop to pick 4 rings of cold-tolerant Pseudomonas verona from the slant solid culture medium and inoculate it into the aerobic denitrifying bacteria culture medium, and inoculate it at a temperature of 10°C. Shake and culture in a full-temperature shaking incubator with a rotation speed of 160 rpm for 48 hours to obtain a cold-tolerant Pseudomonas verona seed liquid (the number of viable bacteria is 2×10 ⁸ colonies/ml). Use an inoculating loop to pick 4 rings of Pseudomonas fluorescens from the slant solid culture medium and inoculate it into the aerobic denitrifying bacteria culture medium, and culture it in a full-temperature shaking incubator with a temperature of 10°C and a rotation speed of 160 rpm for 48 hours. , to obtain Pseudomonas fluorescens seed liquid (the number of viable bacteria is 3×10 ⁸ colonies/ml). Inoculate the cold-tolerant Pseudomonas verona seed solution and Pseudomonas fluorescens into the aerobic denitrifying bacteria medium at an inoculation volume ratio of 3:2 and a total inoculum volume of 10%, and inoculate it at a temperature of 10°C and a rotation speed of 160 rpm /min in a full-temperature shaking incubator for 72 hours to obtain an aerobic and denitrifying compound bacterial solution. The total viable bacterial count of the aerobic and denitrifying compound bacterial solution is 3×10 ⁹ bacterial colonies/ml.

The composition of the aerobic denitrifying bacteria culture medium is: 3.0 g/L sodium citrate, 1.0 g/L sodium nitrate, 0.5 g/L potassium dihydrogen phosphate, 0.2 g/L magnesium sulfate heptahydrate, 0.1 g/L sodium chloride , 0.03 g/L ferrous sulfate heptahydrate, 0.02 g/L anhydrous calcium chloride. Use 10% HCl and NaOH to adjust the pH of the aerobic denitrifying bacteria culture medium to 7.0.

(3) Preparation of phosphorus-polymer compound bacterial solution: Use an inoculating loop to pick 4 rings of Arthrobacter antarcticus from the slant solid culture medium and inoculate it into the phosphorus-polymer culture medium, and shake at full temperature at a temperature of 10°C and a rotation speed of 160 rpm. The culture was shaken in an incubator for 48 hours, and Arthrobacter antarctica was cultured (the number of viable bacteria was 2×10 ⁸ colonies/ml). Use an inoculation loop to pick 4 rings of Halocrystalline Psychrobacterium from the slant solid culture medium and inoculate it into the Phosphorus polyphosphate culture medium. Shake and culture it in a full-temperature shaking incubator with a temperature of 10°C and a rotation speed of 160 rpm for 48 hours to obtain salt. Crystal Psychrobacterium seed liquid (the number of viable bacteria is 3×10 ⁸ colonies/ml). Inoculate Arthrobacter antarcticus seed liquid and Halocrystalline Psychrobacter seed liquid into the phosphate-accumulating bacteria culture medium at an inoculation volume ratio of 1:1 and a total inoculum volume of 10%. Shake and culture in a shaking incubator for 72 hours to obtain a polyphosphorus compound bacterial solution. The total viable bacterial count of the polyphosphorus compound bacterial solution is 2×10 ⁹ bacterial colonies/ml.

The composition of the culture medium for polyphosphate bacteria is: 4.0 g/L sodium acetate, 1.0 g/L ammonium sulfate, 0.03 g/L dipotassium hydrogen phosphate, 0.05 g/L magnesium sulfate heptahydrate, 0.01 g/L calcium chloride, 7.5 g /L 4-Hydroxyethylpiperazineethanesulfonic acid. Use 10% HCl and NaOH to adjust the pH of the culture medium to 7.0.

(4) Preparation of low-temperature-resistant denitrification and phosphorus removal compound microbial inoculants: Mix the heterotrophic nitrification compound bacterial solution, aerobic denitrification compound bacterial solution and phosphorus-polysing compound bacterial solution in a volume ratio of 5:5:12. That is, a low-temperature resistant denitrification and phosphorus removal compound bacterial agent is made. The total viable bacterial count of the composite microbial agent is 3×10 ¹⁰ bacterial colonies/ml.

Application of low-temperature-resistant denitrification and phosphorus-removal compound microbial agents in sewage: Use low-temperature-resistant denitrification and phosphorus-removal compound microbial agents to conduct domestic sewage treatment tests under low-temperature conditions. Domestic sewage is taken from the sewage treatment center of a university campus. The water quality indicators are shown in Table 3.

Table 3 Domestic sewage quality indicators

The low-temperature denitrification and phosphorus removal composite microbial inoculant described in Example 2, Pseudomonas herba, Pseudomonas sludge, Pseudomonas verona, Pseudomonas fluorescens, Arthrobacter antarctica and salt crystals Psychrophilic bacteria were inoculated into 1 liter of domestic sewage. The total inoculation amount of the composite microbial agent and the single bacteria were the same (both were 5 × 10 ² colonies/cm2), and at 10°C, 2.1 cubic meters After aeration for 36 hours at an aeration rate of Domestic sewage was used as a control to calculate the removal rates of ammonia nitrogen, nitrate nitrogen, total nitrogen, total phosphorus and COD. The results are shown in Table 4.

Table 4 Treatment effects of composite microbial agents and single strains on domestic sewage

The removal rates of ammonia nitrogen, nitrate nitrogen, total nitrogen, total phosphorus and COD in domestic sewage under low temperature conditions by the composite microbial agent described in Example 2 are 98.6%, 96.5%, 98.5%, 96.2% and 100% respectively. , the removal rate is significantly improved compared to a single strain. It can be seen that the composite microbial strains formed after compounding can synergistically promote growth and metabolism, effectively improving the removal efficiency of nitrogen and phosphorus in sewage.

Example 3:

(1) Preparation of heterotrophic nitrifying compound bacterial solution: use an inoculating loop to pick 4 rings of cold-tolerant Pseudomonas herbivores from the slant solid culture medium and inoculate them into the heterotrophic nitrifying bacteria culture medium, incubate at a temperature of 15°C and a rotation speed of 140 rpm/ Shake and culture for 24 hours in a full-temperature shaking incubator for 24 minutes to obtain a cold-tolerant Pseudomonas herbiaceus seed liquid (the number of viable bacteria is 2×10 ⁹ colonies/ml). Use an inoculation loop to pick 4 loops of cold-tolerant sludge pseudomonas from the slant solid culture medium and inoculate it into the heterotrophic nitrifying bacteria culture medium, and culture it in a full-temperature shaking incubator with a temperature of 15°C and a rotation speed of 140 rpm for 24 hours. , to obtain a cold-tolerant sludge Pseudomonas seed liquid (the number of viable bacteria is 3×10 ⁹ colonies/ml). The cold-tolerant Pseudomonas herba seed liquid and the cold-tolerant sludge Pseudomonas seed liquid are inoculated at a volume ratio of 1:1 , 20% of the total inoculum amount was simultaneously inoculated into the heterotrophic nitrifying bacteria medium, and cultured with shaking for 48 hours in a full-temperature shaking incubator with a temperature of 14°C and a rotation speed of 140 rpm to obtain a heterotrophic nitrifying compound bacterial solution. The total viable bacterial count of the heterotrophic nitrifying compound bacterial solution is 3×10 ¹⁰ bacterial colonies/ml.

The composition of the heterotrophic nitrifying bacteria culture medium is: 3.5 g/L sodium citrate, 1.5 g/L ammonium sulfate, 0.5 g/L potassium dihydrogen phosphate, 0.3 g/L magnesium sulfate heptahydrate, 0.2 g/L sodium chloride, 0.05 g/L ferrous sulfate heptahydrate, 0.05 g/L anhydrous calcium chloride. Use 10% HCl and NaOH to adjust the pH of the heterotrophic nitrifying bacteria culture medium to 7.0.

(2) Preparation of aerobic denitrifying compound bacterial solution: Use an inoculating loop to pick 4 rings of cold-tolerant Pseudomonas verona from the slant solid culture medium and inoculate it into the aerobic denitrifying bacteria culture medium, and inoculate it at a temperature of 15°C. Shake and culture in a full-temperature shaking incubator with a rotation speed of 140 rpm for 24 hours to obtain a cold-tolerant Pseudomonas verona seed liquid (the number of viable bacteria is 4×10 ⁹ colonies/ml). Use an inoculating loop to pick 4 rings of Pseudomonas fluorescens from the slant solid culture medium and inoculate it into the aerobic denitrifying bacteria culture medium, and culture it in a full-temperature shaking incubator with a temperature of 15°C and a rotation speed of 140 rpm for 24 hours. , to obtain Pseudomonas fluorescens seed liquid (the number of viable bacteria is 2×10 ⁹ colonies/ml). Inoculate the cold-tolerant Pseudomonas verona seed liquid and Pseudomonas fluorescens into the aerobic denitrifying bacteria medium at an inoculation volume ratio of 1:1 and a total inoculum volume of 20%, and inoculate it at a temperature of 15°C and a rotation speed of 140 rpm. /min in a full-temperature shaking incubator for 48 hours to obtain an aerobic and denitrifying compound bacterial solution. The total viable bacterial count of the aerobic and denitrifying compound bacterial solution is 4×10 ¹⁰ bacterial colonies/ml.

The composition of the aerobic denitrifying bacteria culture medium is: 3.5 g/L sodium citrate, 1.0 g/L sodium nitrate, 0.5 g/L potassium dihydrogen phosphate, 0.3 g/L magnesium sulfate heptahydrate, 0.2 g/L sodium chloride , 0.05 g/L ferrous sulfate heptahydrate, 0.05 g/L anhydrous calcium chloride. Use 10% HCl and NaOH to adjust the pH of the aerobic denitrifying bacteria culture medium to 7.0.

(3) Preparation of phosphorus-polymer compound bacterial solution: Use an inoculating loop to pick 4 rings of Arthrobacter antarcticus from the slant solid culture medium and inoculate it into the phosphorus-polymer culture medium, and shake at full temperature at a temperature of 15°C and a rotation speed of 140 rpm. The culture was shaken in an incubator for 24 hours to obtain Arthrobacter antarctica (the number of viable bacteria was 2×10 ⁸ colonies/ml). Use an inoculating loop to pick 4 rings of Halocrystalline Psychrobacterium from the slant solid culture medium and inoculate it into the Phosphate polyphosphate culture medium, and culture it in a full-temperature shaking incubator with a temperature of 10°C and a rotation speed of 140 rpm for 24 hours to obtain Halocrystalline Psychrobacterium seed liquid (the number of viable bacteria is 4×10 ⁸ colonies/ml). Inoculate Arthrobacter antarcticus seed liquid and Halocrystalline Psychrobacter seed liquid into the phosphate-accumulating bacteria culture medium at an inoculation volume ratio of 2:1 and a total inoculum volume of 15%. Shake and culture in a shaking incubator for 48 hours to obtain a polyphosphorus compound bacterial solution. The total viable bacterial count of the polyphosphorus compound bacterial solution is 3×10 ⁹ bacterial colonies/ml.

The composition of the culture medium for polyphosphate bacteria is: 4.5 g/L sodium acetate, 1.5 g/L ammonium sulfate, 1.0 g/L dipotassium hydrogen phosphate, 0.05 g/L magnesium sulfate heptahydrate, 0.03 g/L calcium chloride, 8.5 g /L 4-Hydroxyethylpiperazineethanesulfonic acid. Use 10% HCl and NaOH to adjust the pH of the culture medium to 7.0.

(4) Preparation of low-temperature-resistant denitrification and phosphorus removal compound microbial inoculants: Mix the heterotrophic nitrification compound bacterial solution, aerobic denitrification compound bacterial solution and phosphorus-polymerizing compound bacterial solution in a volume ratio of 1:1:20. That is, a low-temperature resistant denitrification and phosphorus removal compound bacterial agent is made. The total viable bacterial count of the composite microbial agent is 3×10 ¹⁰ bacterial colonies/ml.

Application of low-temperature-resistant denitrification and phosphorus-removal compound microbial agents in sewage: Use low-temperature-resistant denitrification and phosphorus-removal compound microbial agents to conduct domestic sewage treatment tests under low-temperature conditions. Domestic sewage is taken from the sewage treatment center of a university campus. The water quality indicators are shown in Table 5.

Table 5 Domestic sewage quality indicators

The low-temperature denitrification and phosphorus removal composite microbial inoculant described in Example 3, Pseudomonas herba, Pseudomonas sludge, Pseudomonas verona, Pseudomonas fluorescens, Arthrobacter antarctica and salt crystals Psychrophilic bacteria were inoculated into 1 liter of domestic sewage. The total inoculation amount of the composite microbial agent and the single bacteria were the same (both were 4 × 10 ² colonies/cm2), and at 13°C, 2.4 cubic meters After aeration for 24 hours at an aeration rate of Domestic sewage was used as a control to calculate the removal rates of ammonia nitrogen, nitrate nitrogen, total nitrogen, total phosphorus and COD. The results are shown in Table 6.

Table 6 Treatment effects of composite microbial agents and single strains on domestic sewage

The removal rates of ammonia nitrogen, nitrate nitrogen, total nitrogen, total phosphorus and COD in domestic sewage under low temperature conditions by the composite microbial agent described in Example 3 are 99.1%, 98.8%, 99.0%, 97.3% and 100% respectively. , the removal rate is significantly improved compared to a single strain. It can be seen that the composite microbial strains formed after compounding can synergistically promote growth and metabolism, effectively improving the removal efficiency of nitrogen and phosphorus in sewage.

Claims (8)

1. A method for treating sewage by using a low-temperature-resistant denitrification and dephosphorization composite microbial agent is characterized by comprising the following steps:

firstly, preparing a low-temperature-resistant denitrification and dephosphorization composite microbial agent, which comprises the following preparation steps:

(1) Preparing heterotrophic nitrification composite bacterial liquid: 3-4 loops of cold-resistant pseudomonas are selected from the inclined solid culture medium by an inoculating loop and inoculated into the heterotrophic nitrifying bacteria culture medium, and are subjected to shaking culture in a full-temperature shaking incubator at the temperature of 6-15 ℃ and the rotating speed of 120-170 r/min for 24-72 hours to obtain the cold-resistant pseudomonas seed liquid, wherein the viable count is 1 multiplied by 10 ⁷ ～2×10 ⁹ Colony count/ml; inoculating 3-4 loops of cold-resistant pseudomonas from the inclined solid culture medium to the heterotrophic nitrifying bacteria culture medium by using an inoculating loop, and carrying out shaking culture in a full-temperature shaking incubator at the temperature of 6-15 ℃ and the rotating speed of 120-170 r/min for 24-72 hours to obtain cold-resistant pseudomonas seed liquid with the viable count of 1X 10 ⁷ ～2×10 ⁹ Colony count/ml; mixing cold-resistant Pseudomonas putida seed liquid and cold-resistant mush pseudosheetThe volume ratio of the seed liquid of the cell strain is 1-10: 1-10 percent of total inoculum size is inoculated into a heterotrophic nitrifying bacteria culture medium at the same time, and the heterotrophic nitrifying composite bacterial liquid is obtained by shake culture in a full-temperature shake incubator at the temperature of 6-15 ℃ and the rotating speed of 120-170 r/min for 48-96 hours; the total viable count of the heterotrophic nitrification composite bacterial liquid is 1 multiplied by 10 ⁸ ～5×10 ⁹ Colony count/ml;

(2) And (3) preparing an aerobic denitrification compound bacterial liquid: 3-4 loops of cold-resistant veroniona is selected from the inclined solid culture medium by an inoculating loop, inoculated into an aerobic denitrifying bacteria culture medium and subjected to shaking culture in a full-temperature shaking incubator at the temperature of 6-15 ℃ and the rotating speed of 120-170 r/min for 24-72 hours, so as to obtain cold-resistant veroniona seed liquid, wherein the viable count is 1 multiplied by 10 ⁷ ～2×10 ⁹ Colony count/ml; 3-4 loops of fluorescent pseudomonas are selected from the inclined plane solid culture medium by an inoculating loop and inoculated into an aerobic denitrifying bacteria culture medium, and the fluorescent pseudomonas seed liquid is obtained by shaking culture for 24-72 hours in a full-temperature shaking incubator with the temperature of 6-15 ℃ and the rotating speed of 120-170 r/min, and the viable count is 1 multiplied by 10 ⁷ ～2×10 ⁹ Colony count/ml; the pseudomonas cold-resistant veronii seed solution and the pseudomonas fluorescens are inoculated according to the volume ratio of 1-10: 1-10 percent of total inoculum size is inoculated into an aerobic denitrifying bacteria culture medium, and shake culture is carried out in a full-temperature shake incubator at the temperature of 6-15 ℃ and the rotating speed of 120-170 r/min for 48-96 hours, thus obtaining a well-cultured denitrifying composite bacterial liquid; the total viable count of the aerobic denitrification compound bacterial liquid is 1 multiplied by 10 ⁸ ～5×10 ⁹ Colony count/ml;

preparing phosphorus-accumulating composite bacterial liquid: inoculating 3-4 loops of Antarctic Arthrobacter from the inclined solid culture medium into the phosphorus accumulating bacteria culture medium, and shake culturing in a full-temperature shake incubator at 6-15deg.C and 120-170 rpm for 23-72 hr to obtain Antarctic Arthrobacter with viable count of 1×10 ⁷ ～2×10 ⁹ Colony count/ml; inoculating 3-4 loops of salt crystal psychrophilic bacillus to the phosphorus accumulating bacteria culture medium with inoculating loop, and oscillating culturing in a full-temperature oscillating incubator at 6-15 deg.c and 120-170 rpm for 24-72 hr to obtain the productTo the seed liquid of the salt crystal psychrophilic bacillus, the viable count is 1 multiplied by 10 ⁷ ～2×10 ⁹ Colony count/ml; the seed solution of the Antarctic arthrobacter and the seed solution of the salt crystal psychrophilic bacilli are mixed according to the volume ratio of the inoculation amount of 1-10: 1-10 percent of total inoculum size is inoculated into a phosphorus accumulating bacteria culture medium, and the phosphorus accumulating composite bacteria liquid is obtained by shake culture in a full-temperature shake incubator at the temperature of 6-15 ℃ and the rotating speed of 120-170 r/min for 48-96 hours; the total viable count of the phosphorus-accumulating composite bacterial liquid is 1 multiplied by 10 ⁸ ～5×10 ⁹ Colony count/ml;

(3) Preparation of low-temperature-resistant denitrification and dephosphorization composite microbial agent: the heterotrophic nitrification composite bacterial liquid, the aerobic denitrification composite bacterial liquid and the phosphorus-accumulating composite bacterial liquid are mixed according to the volume ratio of 1-10: 1 to 10: 1-20, and preparing the low-temperature-resistant denitrification and dephosphorization composite microbial agent; the total viable count of the composite microbial agent is not less than 1×10 ¹⁰ Colony count/ml;

the low-temperature-resistant denitrification and dephosphorization composite microbial agent is applied to low-temperature biological sewage treatment and comprises the following steps:

the additive amount in the urban sewage to be treated is 2 multiplied by 10 ² ～5×10 ² The low temperature resistant nitrogen and phosphorus removal compound microbial agent with colony count/square centimeter is aerated for 24 to 48 hours with aeration quantity of 1.0 to 3.5 cubic meters/hour, and is filtered to obtain the water after standing for 20 to 30 minutes.

2. The method for treating sewage by using the low-temperature-resistant denitrification and dephosphorization composite microbial agent as claimed in claim 1, wherein the heterotrophic nitrification composite microbial agent is prepared from cold-resistant pseudomonas and cold-resistant mush-resistant pseudomonas which are both sewage treatment plant sedimentation tank activated sludge, and are respectively identified as pseudomonas grass through 16SrDNA sequence analysisPseudomonas poae) And Pseudomonas mussaendaPseudomonas peli)。

3. The method for treating sewage by using the low-temperature-resistant denitrification and dephosphorization composite microbial agent according to claim 1, which is characterized in that the heterotrophic nitrification composite microbial liquid is prepared, and a heterotrophic nitrifying bacteria culture medium comprises the following components: 1.0 to 5.0 g/liter of sodium citrate, 0.2 to 1.0 g/liter of ammonium sulfate, 0.3 to 1.5 g/liter of monopotassium phosphate, 0.1 to 1.0 g/liter of magnesium sulfate heptahydrate, 0.1 to 1.0 g/liter of sodium chloride, 0.01 to 0.1 g/liter of ferrous sulfate heptahydrate, 0.01 to 0.1 g/liter of anhydrous calcium chloride; the pH of the heterotrophic nitrifier culture medium is adjusted to 6.5-7.5 by adopting 10% HCl and NaOH.

4. The method for treating sewage by using the low-temperature-resistant denitrification and dephosphorization composite microbial agent according to claim 1, which is characterized in that the heterotrophic nitrification composite microbial agent is prepared from cold-resistant pseudomonas and fluorescent pseudomonas which are both river water frozen sediment, and are respectively identified as pseudomonas veronii by 16SrDNA sequence analysisPseudomonas veronii) And Pseudomonas fluorescens [ ]Pseudomonas fluorescens)。

5. The method for treating sewage by using the low-temperature-resistant denitrification and dephosphorization composite microbial agent according to claim 1, which is characterized in that the preparation of the aerobic denitrification composite microbial agent is characterized in that an aerobic denitrification bacterial culture medium comprises the following components: 1.0 to 5.0 g/l sodium citrate, 0.2 to 2.0 g/l sodium nitrate, 0.3 to 1.5 g/l monopotassium phosphate, 0.1 to 1.0 g/l magnesium sulfate heptahydrate, 0.1 to 1.0 g/l sodium chloride, 0.01 to 0.1 g/l ferrous sulfate heptahydrate, 0.01 to 0.1 g/l anhydrous calcium chloride; the pH of the aerobic denitrifying bacteria culture medium is adjusted to 6.5-7.5 by adopting 10% HCl and NaOH.

6. The method for treating sewage by using the low-temperature-resistant denitrification and dephosphorization composite microbial agent according to claim 1, which is characterized in that a QHZ-98A type full-temperature shaking incubator is adopted for microbial liquid culture.

7. The method for treating sewage by using the low-temperature-resistant denitrification and dephosphorization composite microbial agent according to claim 1, which is characterized in that the heterotrophic nitrifying bacteria culture medium, the aerobic denitrifying bacteria culture medium and the phosphorus accumulating bacteria culture medium are subjected to high-pressure steam sterilization treatment under the treatment condition that the temperature is 121 ℃ and the pressure is 0.105 megapascal, and the treatment time is 20-30 minutes.

8. The method for treating sewage by using the low-temperature-resistant denitrification and dephosphorization composite microbial agent according to claim 7, wherein the high-pressure steam sterilization adopts an SN210C type vertical pressure steam sterilizer.