CN110683639A

CN110683639A - Solid carbon source for promoting low-temperature denitrification and preparation method and application thereof

Info

Publication number: CN110683639A
Application number: CN201910861940.2A
Authority: CN
Inventors: 赵迎新; 刘朵; 季民; 杨知凡
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2019-09-12
Filing date: 2019-09-12
Publication date: 2020-01-14

Abstract

The invention belongs to the technical field of sewage treatment, and particularly relates to a solid carbon source for promoting low-temperature denitrification, which comprises the following components in parts by mass: 40-70 parts of polypropylene master batch, 20-50 parts of degradable high polymer, 20-50 parts of natural degradable biomass, 0.5-1.5 parts of quinone substances, 0.5-1 part of zeatin, 0.5-1 part of dissolving agent and 3-7 parts of other components. Compared with the prior art, the solid carbon source is non-toxic and has good biological affinity, and the contained carbon source substances are easy to be utilized by microorganisms, thereby being beneficial to the rapid recovery of the activity of the denitrifying bacteria in a low-temperature environment and improving the operation effect of the biological denitrification treatment process. In addition, the invention also provides a preparation method of the solid carbon source for promoting the low-temperature denitrification, which is simple to operate and can be processed into products with specific shapes.

Description

Solid carbon source for promoting low-temperature denitrification and preparation method and application thereof

Technical Field

The invention belongs to the technical field of sewage treatment, and particularly relates to a solid carbon source for promoting low-temperature denitrification, and a preparation method and application thereof.

Background

At present, urban sewage in China is generally subjected to low carbon source conversion, the carbon-nitrogen ratio is low, the denitrification is limited, especially the carbon-nitrogen ratio of the urban sewage in winter is unstable, and microbial fillers used in the existing process generally do not have the function of releasing a carbon source. In addition, temperature has an extremely important influence on the efficiency of the biological denitrification process. The optimal conditions for the normal growth of the denitrifying bacteria are that the temperature is 20-35 ℃, the dissolved oxygen is less than or equal to 0.5mg/L, and when the temperature is less than or equal to 15 ℃, the reproduction rate, the metabolic rate and the biological activity of the denitrifying bacteria are all reduced, and the dissolved oxygen is increased along with the reduction of the temperature, so that the anaerobic denitrifying bacteria are inhibited, and the denitrification efficiency is reduced. In the prior art, main means for improving the denitrification treatment efficiency under the low-temperature condition include additional carbon source adding, sludge load reduction, nitrobacteria culture or indoor structure construction and the like, but the means greatly increase the cost of sewage treatment.

Disclosure of Invention

One of the objects of the present invention is: aiming at the defects of the prior art, the solid carbon source for promoting low-temperature denitrification is provided, and the engineering problems that the activity of microorganisms is reduced under the low-temperature condition and the operation effect of the biological denitrification treatment process is poor are solved.

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

a solid carbon source for promoting low-temperature denitrification comprises the following components in parts by mass: 40-70 parts of polypropylene master batch, 20-50 parts of degradable high polymer, 20-50 parts of natural degradable biomass, 0.5-1.5 parts of quinone substances, 0.5-1 part of zeatin, 0.5-1 part of dissolving agent and 3-7 parts of other components.

As an improvement of the solid carbon source for promoting the low-temperature denitrification, the degradable high polymer is any one of poly (3-hydroxybutyrate-3-hydroxyvalerate), polylactic acid, poly epsilon-caprolactone, poly butylene succinate and polyvinyl alcohol.

As an improvement of the solid carbon source for promoting the low-temperature denitrification, the natural degradable biomass is any two of crab shell chitin, starch and straw powder.

As an improvement of the solid carbon source for promoting low-temperature denitrification, the quinone substances are at least one of humic acid, riboflavin and anthraquinone-2-sodium sulfonate.

As an improvement of the solid carbon source for promoting the low-temperature denitrification, the dissolving agent is a mixed solution of N, N-dimethylformamide, ethanol and water.

As an improvement of the solid carbon source for promoting the low-temperature denitrification, the mass ratio of the N, N-dimethylformamide to the ethanol to the water is 1 (1-5) to 10-20.

As an improvement of the solid carbon source for promoting the low-temperature denitrification, the other components are a mixed solution of ferrous chloride, magnesium chloride and water.

As an improvement of the solid carbon source for promoting the low-temperature denitrification, the mass ratio of the ferrous chloride, the magnesium chloride and the water is (0.5-1): 10.

The second purpose of the invention is: the preparation method of the solid carbon source for promoting low-temperature denitrification comprises the following steps:

weighing raw materials of all components according to parts by weight and uniformly mixing;

and step two, processing the filaments obtained in the step one into braided tapes.

The third purpose of the invention is that: provides the application of the solid carbon source for promoting low-temperature denitrification in the field of sewage treatment.

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

1) the solid carbon source is non-toxic and has good biological affinity, and the carbon source substances contained in the solid carbon source are easy to be utilized by microorganisms, thereby being beneficial to the rapid recovery of the activity of denitrifying bacteria in a low-temperature environment and improving the operation effect of the biological denitrification treatment process.

2) The process for preparing the solid carbon source is simple and easy to operate, and the solid carbon source can be processed into products with other specific shapes besides the shapes mentioned in the invention.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

Examples 1 to 5

The preparation method of the solid carbon source for promoting low-temperature denitrification comprises the following steps:

step one, weighing raw materials of each component according to the mass parts listed in table 1, and uniformly mixing in a mixer;

and step two, feeding the obtained product in the step one into a plastic wire drawing machine, processing the product into filaments, and making the filaments into a braided belt shape through a textile machine.

Table 1 composition of raw materials for each example

The dissolving agent is a mixed solution of N, N-dimethylformamide, ethanol and water, and the mass ratio of the N, N-dimethylformamide to the ethanol to the water is 1 (1-5) to 10-20; the other components are mixed liquid of ferrous chloride, magnesium chloride and water, and the mass ratio of the ferrous chloride to the magnesium chloride to the water is (0.5-1): 10.

Performance testing

The following experiments were conducted on the solid carbon sources prepared in examples 1 to 5, respectively, to test their performances.

6 groups of denitrification biomembrane reactors are operated in parallel, one group is a control group, no solid carbon source is added, and the other five groups are the solid carbon sources prepared in the above embodiment. The running period of the reactor is 4h, and the effective treatment water amount per period is 0.8L. Adopts artificial self-water distribution, the nitrate nitrogen concentration of inlet water is 50mg/L, and the COD concentration is 150 mg/L. The reactor is provided with a cooling water circulation device, and the internal temperature is kept at (10 +/-1) DEG C. The inoculated sludge is taken from the return sludge of a secondary sedimentation tank of a certain sewage treatment plant in Tianjin city.

After the reactor had been operated for 3 days, 7 days and 10 days, the NO of the reactor effluent was calculated₃ ^-N removal, the specific results are given in Table 2.

TABLE 2 Nitro-nitrogen removal at Low temperature for the examples

Number of days

Control group

Example 1

Example 2

Example 3

Example 4

Example 5

3

45～50

＞95

85～90

＞95

85～90

7

45～50

85～90

80～85

75～80

10

45～50

80～85

85～90

75～80

80～85

70～75

As can be seen from Table 2, the removal rate of nitronium nitride is significantly higher than that of the control group after the solid carbon source is adopted in examples 1-5. Specifically, after the solid carbon source is added in examples 1 to 5, the removal rate of nitrone can reach 90% in 3 days, it should be noted that, due to the consumption of the solid carbon source, the removal rate of nitrone slightly decreases in 7 days, the removal rate of nitrone can still reach 80% in 10 days, and the metabolic activity of the denitrifying bacteria is still active compared with that of the control group. In particular, the removal of nitrate and nitrogen from solid carbon sources containing starch and riboflavin (examples 1, 2 and 4) was superior to other solid carbon sources (examples 3 and 5). Therefore, substances contained in the solid carbon source are easy to utilize by microorganisms, and can promote the metabolism of the microorganisms to a certain extent, thereby being beneficial to the rapid recovery of the activity of denitrifying bacteria under the low-temperature condition.

Variations and modifications to the above-described embodiments may also occur to those skilled in the art, which fall within the scope of the invention as disclosed and taught herein. Therefore, the present invention is not limited to the above-mentioned embodiments, and any obvious improvement, replacement or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. The solid carbon source for promoting low-temperature denitrification is characterized by comprising the following components in parts by mass: 40-70 parts of polypropylene master batch, 20-50 parts of degradable high polymer, 20-50 parts of natural degradable biomass, 0.5-1.5 parts of quinone substances, 0.5-1 part of zeatin, 0.5-1 part of dissolving agent and 3-7 parts of other components.

2. The solid carbon source for promoting low-temperature denitrification according to claim 1, wherein the degradable polymer is any one of poly (3-hydroxybutyrate-3-hydroxyvalerate), polylactic acid, poly-epsilon-caprolactone, polybutylene succinate and polyvinyl alcohol.

3. The solid carbon source for promoting low-temperature denitrification according to claim 1, wherein the natural degradable biomass is any two of crab shell chitin, starch and straw powder.

4. The solid carbon source for promoting low-temperature denitrification according to claim 1, wherein the quinone-like substance is at least one of humic acid, riboflavin, and sodium anthraquinone-2-sulfonate.

5. The solid carbon source for promoting low-temperature denitrification according to claim 1, wherein the dissolving agent is a mixture of N, N-dimethylformamide, ethanol and water.

6. The solid-state carbon source for promoting low-temperature denitrification according to claim 5, wherein: the mass ratio of the N, N-dimethylformamide to the ethanol to the water is 1 (1-5) to 10-20.

7. The solid-state carbon source for promoting low-temperature denitrification according to claim 1, wherein the other component is a mixture of ferrous chloride, magnesium chloride and water.

8. The solid-state carbon source for promoting low-temperature denitrification according to claim 7, wherein: the mass ratio of the ferrous chloride to the magnesium chloride to the water is (0.5-1): 10.

9. The preparation method of the solid carbon source for promoting low-temperature denitrification, which is described in any one of claims 1 to 8, is characterized by comprising the following steps:

10. Application of the solid carbon source for promoting low-temperature denitrification as defined in any one of claims 1-8 in the field of sewage treatment.