CN113860492A - Control method, woody carbon source and application of denitrifying woody carbon source based on reducing sugar yield - Google Patents

Abstract

The invention provides a method for regulating and controlling carbon release amount of a denitrifying wood carbon source based on reducing sugar yield, which comprises the steps of determining an optimal value of a denitrifying rate through a test under a simulated application environment condition, obtaining a reducing sugar yield target value suitable for the wood carbon source under the same application environment condition, and establishing the reducing sugar yield and Ca (OH)₂Amount of (a), and reducing sugar yield and C₂H₄O₃The yield of the target reducing sugar is brought into a corresponding equation, thereby determining proper treatment conditions to release carbon for the wood carbon sourceThe purpose of quantity regulation. The regulating and controlling method can regulate and control the carbon releasing capacity of the wood carbon source according to the actual situation to obtain the required carbon source, and avoids the problems of poor reaction effect caused by too small carbon releasing amount of the carbon source and secondary pollution caused by too much carbon releasing amount.

Description

Carbon release amount regulation method of denitrifying wood carbon source based on reducing sugar yield, wood carbon source and application

Technical Field

The invention relates to the technical field of preparation of a denitrifying wood carbon source, and particularly relates to a method for regulating and controlling carbon release amount of the denitrifying wood carbon source based on reducing sugar yield, the wood carbon source and application.

Background

Nitrate is one of four main pollutants in underground water, and has the characteristics of human stress, wide pollution range distribution, strong migration capacity, complex pollution path and the like. The sewage and garbage discharged from rural areas are important sources of nitrate pollution of underground water, the sewage and garbage discharged from rural life and livestock and poultry breeding contain a large amount of nitrogen-containing substances, the substances are converted into nitrate with strong migration capability under the natural action, and the nitrate exceeds the natural purification capability, so that the nitrate continuously permeates into the underground, and the nitrate in the underground water tends to rise year by year. And high concentrations of nitrate pose a significant threat to groundwater drinking water safety. It has been shown that ingestion of nitrate in high concentrations by humans can lead to "blue baby disease", methemoglobinemia and cancer, among other conditions. Therefore, China limits the nitrate concentration in the underground drinking water source, and the nitrate nitrogen concentration is specified to be lower than 20 mg/L.

Biological denitrification is the main natural role of nitrate removal, but is limited to anoxic and organic environmental conditions, occurring only in local areas or for certain periods of time. For this reason, the biological denitrification is usually enhanced by adding organic substances, and the organic carbon sources to be added are classified into liquid type and solid type. The liquid carbon source mainly comprises methanol, ethanol, sodium acetate, glucose and the like, but the carbon source has the characteristics of high cost and complex control conditions and cannot adapt to rural pollution. The solid carbon source avoids the disadvantages of liquid carbon sources, and can be divided into artificially synthesized and natural materials, and the natural materials are paid attention because of low price and easy acquisition.

The natural materials adopt straw, corncob, rice husk and other materials as denitrification carbon source materials, the materials show higher denitrification rate at the initial stage, but the denitrification effect is obviously reduced along with the prolonging of the reaction time, and the continuous and stable denitrification efficiency within a plurality of years is difficult to ensure. The woody biomass has the advantages of high carbon-nitrogen ratio, low price, easy obtainment, small side reaction, long service life and the like, is the most widely natural material in current research and application, and is also in accordance with the characteristics of pollution control in rural areas. However, this material is limited to natural components and structural features and is poorly bioavailable, resulting in a low rate of biological denitrification when used as a carbon source.

The poor bioavailability of woody biomass is due primarily to the lignin content and the manner of incorporation in the biomass. Lignin, as a component difficult to be bioavailable, is tightly entangled with cellulose and hemicellulose, and also limits the utilization of other components by microorganisms. In the prior art, methods for removing lignin from biomass include alkali treatment, acid treatment, physical treatment and the like. Wherein, the alkali treatment and the peroxyacetic acid treatment have stronger selectivity for removing lignin, and the effective solid components as the carbon source are reserved to a greater extent. However, the current treatment of woody biomass basically considers how to remove lignin to the maximum extent so that the microorganisms can utilize more of the available solid components (cellulose and hemicellulose). However, for woody biomass as a carbon source, the more lignin is not removed, the better the denitrification effect is, and on the contrary, when a sewage environment to be treated does not need a large amount of carbon source, the excessive exposure of effective solid components as a carbon source may cause secondary pollution of organic matters and ammonia nitrogen and a reduction in service life.

Therefore, a regulation method is needed to regulate the carbon release amount of the wood carbon source according to the carbon demand of the denitrifying microorganism under the actual application environment condition, so as to obtain a proper wood carbon source.

Disclosure of Invention

The invention aims to provide a method for regulating and controlling the carbon release amount of a denitrifying wood carbon source based on the yield of reducing sugar, which aims to solve the problems of poor reaction effect caused by too small carbon release amount as a carbon source, secondary pollution caused by too much carbon release amount and reduction of service life caused by too much carbon release amount by establishing the relationship between the yield of reducing sugar of the wood carbon source and a treatment agent and the relationship between the yield of reducing sugar and a denitrifying rate when the wood carbon source is treated, so that the required carbon source can be obtained by regulating and controlling the carbon release capacity of the wood carbon source according to the actual situation.

According to the first aspect of the invention, the method for regulating and controlling the carbon release amount of the denitrifying wood carbon source based on the yield of reducing sugar comprises the following specific steps:

establishing a simulation test:

simulating the environmental conditions of the water body to be treated, establishing a water environment simulation system, and dividing the water body of the water environment simulation system into two equal parts;

performing denitrification test on a first wood carbon source to remove nitrate in the water environment simulation system, drawing a first nitrate concentration-time dynamics characteristic curve according to the test result, and testing the reducing sugar yield A of the first wood carbon source; wherein the first wood carbon source is untreated crushed wood;

removing nitrate in the simulated water environment by adopting a second wood carbon source in the other water body, and drawing a second nitrate concentration-time dynamics characteristic curve according to the test result; wherein the second wood carbon source is C₂H₄O₃After treatment, the removal rate of lignin is more than or equal to 80 percent of broken wood;

determination of the desired reducing sugar yield B:

obtaining a first denitrification rate V under the condition of a first wood carbon source according to a first nitrate concentration-time dynamics characteristic curve₁Obtaining a second denitrification rate V under the condition of a second wood carbon source according to a second nitrate concentration-time dynamics characteristic curve₂；

The desired reducing sugar yield B satisfies formula (1):

regulating and controlling the carbon release amount of the wood carbon source:

if the value B is within the first reducing sugar yield interval, substituting the value B into a first equation;

wherein, the first reducing sugar yield interval and the first equation are obtained by the following method:

s1, placing equal amount of untreated wood chips in n Ca (OH) with different concentrations₂Reacting in a constant temperature shaking table, washing the reacted broken wood with water until the filtrate is neutral, and drying to obtain Ca (OH) with different concentrations₂The crushed wood after solution treatment was tested for reducing sugar yield C_iObtaining a first reducing sugar yield interval (A, C)]And establish Ca (OH)₂Obtaining a first equation after linear fitting according to a relation curve of the adding amount and the yield of corresponding reducing sugar; wherein, i is 1,2 … … n, C is C_iMaximum value of (1);

substituting the B value into the first equation to obtain the corresponding target Ca (OH)₂Concentration of and in the target Ca (OH)₂Under the condition of concentration, treating the untreated crushed wood according to the method of S1 to obtain a target wood carbon source of carbon release amount required by the water environment to be treated;

if the value B is within the second reducing sugar yield interval, substituting the value B into a second equation;

wherein, the second reducing sugar yield interval and the second equation obtaining method are as follows:

s21, placing equal amount of untreated wood chips in n Ca (OH) with different concentrations₂Reacting in a constant temperature shaking table, washing the reacted broken wood with water until the filtrate is neutral, and drying to obtain Ca (OH) with different concentrations₂The crushed wood after solution treatment was tested for reducing sugar yield C_iObtaining a first reducing sugar yield interval (A, C)]Determining the treated wood chips corresponding to the reducing sugar yield C as a third wood carbon source; wherein, i is 1,2 … … n, C is C_iMaximum value of (1);

s22, respectively placing an equal amount of third wood carbon source in m C with different concentrations₂H₄O₃In the solution, reacting in a constant temperature shaking table, after the reaction is finished, washing the reacted third wood carbon source with water until the filtrate is neutral, and drying to obtain C with different concentrations₂H₄O₃The crushed wood after the solution treatment is tested, and the reducing sugar yield D of a third wood carbon source after the treatment is respectively tested_jObtaining a second reducing sugar yield interval (C, D)]And building C₂H₄O₃Obtaining a second equation by linear fitting of a relation curve of the adding amount and the yield of the corresponding reducing sugar, wherein j is 1,2 … … m, and D is D_jMaximum value of (1);

substituting the value B into the second equation to obtain a corresponding target C₂H₄O₃Concentration of at the target C₂H₄O₃And under the condition of concentration, treating the third wood carbon source according to the method of S22 to obtain the target wood carbon source with the carbon release amount required by the water environment to be treated.

Preferably, the crushed wood is poplar crushed wood.

Preferably, the first equation is as shown in equation (2):

y₁＝1251.5x₁+25.944 (2)

in the formula: x is the number of₁Is Ca (OH)₂Amount of addition, g/g_{Carbon source}；y₁Is added by an amount x₁Ca (OH)₂Reducing sugar yield of the treated crushed wood, mg/g_{Carbon source}。

Preferably, the second equation is as shown in equation (3):

y₂＝1344.4x₂+150.05 (3)

in the formula: x is the number of₂Is C₂H₄O₃Amount of addition, g/g_{Carbon source}；y₂Is added by an amount x₂In mg/g of_{Carbon source}Reducing sugar yield in mg/g of the treated third woody carbon source_{Carbon source}。

Preferably, the first reducing sugar yield interval is (31.3, 148.1)]，mg/g_{Carbon source}。

Preference is given toThe yield interval of the second reducing sugar is (148.1, 600.5)]，mg/g_{Carbon source}。

Preferably, in the steps S1 and S21, the treatment conditions of the crushed wood are as follows: crushed wood and Ca (OH)₂The solid-liquid ratio of the solution is 1:10, the temperature of a constant temperature shaking table is 90 ℃, the rotating speed is 150rpm, the reaction time is 24h, and the drying temperature is 60 ℃.

Preferably, in step S22, the third wood carbon source is mixed with C₂H₄O₃The solid-liquid ratio of the solution is 1:10, the temperature of a constant temperature shaking table is 50 ℃, the rotating speed is 150rpm, the reaction time is 12h, and the drying temperature is 60 ℃.

According to a second aspect of the present invention, there is provided a wood carbon source prepared by the method for controlling the carbon release amount of the denitrifying wood carbon source based on the yield of reducing sugar.

According to a third aspect of the invention, the application of the wood carbon source in treating rural sewage by a biological denitrification method is provided.

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

1. the method for regulating and controlling the carbon release amount of the denitrifying wood carbon source determines the reducing sugar yield of the wood carbon source under the condition of optimal denitrifying rate through a simulation test, and then according to the established reducing sugar yield and Ca (OH)₂Amount of (a), and reducing sugar yield and C₂H₄O₃The proper treatment conditions are determined according to the relationship between the amounts of the carbon sources, so that the regulation and control of the carbon release amount of the wood carbon source are realized, the conformity between the regulation and control of the carbon release amount of the wood carbon source and the utilization rate of denitrifying organisms is ensured, the problems of poor reaction effect caused by too little carbon release amount and secondary pollution caused by too much carbon release amount when the carbon source is used as the carbon source are avoided, and the long-term service life and the stable denitrifying effect of the wood carbon source are maintained.

2. When the method is used for treating the wood carbon source, Ca (OH) is firstly adopted₂The primary treatment is carried out at a lower temperature and under normal pressure, the conditions are mild, the cost is low, and the waste liquid can be introduced into carbon dioxide to form calcium carbonate, so that the medicament and lignin are recovered, and the recycling of the waste water is facilitated; when the release of wood carbon source is neededWhen more carbon is available, adopting C as the wood carbon source after the first-stage treatment₂H₄O₃The secondary treatment is carried out under the conditions of lower temperature and normal pressure, so that the use amount of the medicament is reduced while the treatment effect is ensured; the whole treatment process has the advantages of mild conditions, good effect, easy control and low cost, reduces the risk of secondary pollution and is favorable for further popularization and application.

Drawings

FIG. 1 is a graph showing the variation of the amount of calcium hydroxide added and the reducing sugar yield of a woody carbon source according to the present invention.

FIG. 2 is a graph showing the variation of the amount of peracetic acid added according to the present invention with the reducing sugar yield of a woody carbon source.

FIG. 3 is a nitrate concentration-time kinetic profile of example 2.

FIG. 4 is a nitrate concentration-time kinetic profile of example 3.

FIG. 5 is a linear relationship between lignin content and reducing sugar yield of ground wood under the chemical treatment conditions of the present invention.

Detailed Description

In order to better understand the technical content of the present invention, specific embodiments are described below with reference to the accompanying drawings.

In this disclosure, aspects of the present invention are described with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. Embodiments of the present disclosure are not necessarily intended to include all aspects of the invention. It should be appreciated that the various concepts and embodiments described above, as well as those described in greater detail below, may be implemented in any of numerous ways.

The invention provides a method for regulating and controlling carbon release amount of a denitrifying wood carbon source based on reducing sugar yield, which determines the target reducing sugar yield of the wood carbon source under the condition of optimal denitrifying rate through a simulation test, and then establishes the reducing sugar yield and Ca (OH)₂Amount of (a), and reducing sugar yield and C₂H₄O₃The yield of the target reducing sugar is brought into a corresponding equation, thereby determining the proper treatment condition and achieving the purpose of releasing carbon quantity to the wood carbon sourceThe purpose of regulation and control.

In a specific embodiment, a carbon release amount regulation method of a denitrifying wood carbon source based on reducing sugar yield is provided, and comprises the following specific steps:

establishing a simulation test:

simulating the environmental conditions of the water body to be treated, establishing a water environment simulation system, and dividing the water body of the water environment simulation system into two equal parts;

performing denitrification test on a first wood carbon source to remove nitrate in the water environment simulation system, drawing a first nitrate concentration-time dynamics characteristic curve according to the test result, and testing the reducing sugar yield A of the first wood carbon source; wherein the first wood carbon source is untreated crushed wood;

removing nitrate in the simulated water environment by adopting a second wood carbon source in the other water body, and drawing a second nitrate concentration-time dynamics characteristic curve according to the test result; wherein the second wood carbon source is C₂H₄O₃After treatment, the removal rate of lignin is more than or equal to 80 percent of broken wood;

determination of the desired reducing sugar yield B:

obtaining a first denitrification rate V under the condition of a first wood carbon source according to a first nitrate concentration-time dynamics characteristic curve₁Obtaining a second denitrification rate V under the condition of a second wood carbon source according to a second nitrate concentration-time dynamics characteristic curve₂；

The desired reducing sugar yield B satisfies formula (1):

regulating and controlling the carbon release amount of the wood carbon source:

if the value B is within the first reducing sugar yield interval, substituting the value B into a first equation;

wherein, the first reducing sugar yield interval and the first equation are obtained by the following method:

s1, mixing the same amountPlacing the untreated crushed wood in n Ca (OH) with different concentrations respectively₂Reacting in a constant temperature shaking table, washing the reacted broken wood with water until the filtrate is neutral, and drying to obtain Ca (OH) with different concentrations₂The crushed wood after solution treatment was tested for reducing sugar yield C_iObtaining a first reducing sugar yield interval (A, C)]And establish Ca (OH)₂Obtaining a first equation after linear fitting according to a relation curve of the adding amount and the yield of corresponding reducing sugar; wherein, i is 1,2 … … n, C is C_iMaximum value of (1);

substituting the B value into the first equation to obtain the corresponding target Ca (OH)₂Concentration of and in the target Ca (OH)₂Under the condition of concentration, treating the untreated crushed wood according to the method of S1 to obtain a target wood carbon source of carbon release amount required by the water environment to be treated;

if the value B is within the second reducing sugar yield interval, substituting the value B into a second equation;

wherein, the second reducing sugar yield interval and the second equation obtaining method are as follows:

s21, placing equal amount of untreated wood chips in n Ca (OH) with different concentrations₂Reacting in a constant temperature shaking table, washing the reacted broken wood with water until the filtrate is neutral, and drying to obtain Ca (OH) with different concentrations₂The crushed wood after solution treatment was tested for reducing sugar yield C_iObtaining a first reducing sugar yield interval (A, C)]Determining the treated wood chips corresponding to the reducing sugar yield C as a third wood carbon source; wherein, i is 1,2 … … n, C is C_iMaximum value of (1);

s22, respectively placing an equal amount of third wood carbon source in m C with different concentrations₂H₄O₃In the solution, reacting in a constant temperature shaking table, after the reaction is finished, washing the reacted third wood carbon source with water until the filtrate is neutral, and drying to obtain C with different concentrations₂H₄O₃The crushed wood after the solution treatment is tested, and the reducing sugar yield D of a third wood carbon source after the treatment is respectively tested_jObtaining a second reducing sugar yield interval (C, D)]And building C₂H₄O₃Obtaining a second equation by linear fitting of a relation curve of the adding amount and the yield of the corresponding reducing sugar, wherein j is 1,2 … … m, and D is D_jMaximum value of (1);

substituting the value B into the second equation to obtain a corresponding target C₂H₄O₃Concentration of at the target C₂H₄O₃And under the condition of concentration, treating the third wood carbon source according to the method of S22 to obtain the target wood carbon source with the carbon release amount required by the water environment to be treated.

In a preferred embodiment, the crushed wood is poplar crushed wood. It should be understood that the types of wood pieces, including but not limited to aspen wood pieces, may be selected as appropriate.

In a preferred embodiment, the first equation is shown in equation (2):

y₁＝1251.5x₁+25.944 (2)

in the formula: x is the number of₁Is Ca (OH)₂Amount of addition, g/g_{Carbon source}；y₁Is added by an amount x₁Ca (OH)₂Reducing sugar yield of the treated crushed wood, mg/g_{Carbon source}。

In a preferred embodiment, the second equation is as shown in equation (3):

y₂＝1344.4x₂+150.05 (3)

in the formula: x is the number of₂Is C₂H₄O₃Amount of addition, g/g_{Carbon source}；y₂Is added by an amount x₂In mg/g of_{Carbon source}Reducing sugar yield in mg/g of the treated third woody carbon source_{Carbon source}。

The method for obtaining the first equation is obtained by performing linear fitting by taking the adding amount of calcium hydroxide as an X axis and taking the reducing sugar yield of the crushed wood treated by the calcium hydroxide corresponding to the adding amount as a Y axis.

The method for obtaining the second equation is obtained by performing linear fitting with the addition amount of peroxyacetic acid as an X-axis and the reducing sugar yield of the crushed wood treated by the corresponding addition amount of peroxyacetic acid as a Y-axis.

It should be understood that the above method of linear fitting is a conventional technical means, and is not described in detail herein.

In a preferred embodiment, the first reducing sugar yield interval is (31.3, 148.1)]，mg/g_{Carbon source}。

In a preferred embodiment, the second reducing sugar yield interval is (148.1, 600.5)]，mg/g_{Carbon source}。

In a preferred embodiment, in step S1, the conditions for processing the crushed wood are as follows: crushed wood and Ca (OH)₂The solid-liquid ratio of the solution is 1:10, the temperature of a constant temperature shaking table is 90 ℃, the rotating speed is 150rpm, the reaction time is 24h, and the drying temperature is 60 ℃.

In a preferred embodiment, in the step S1, the first wood carbon source is mixed with C₂H₄O₃The solid-liquid ratio of the solution is 1:10, the temperature of a constant temperature shaking table is 50 ℃, the rotating speed is 150rpm, the reaction time is 12h, and the drying temperature is 60 ℃.

In a further preferred embodiment, the reducing sugar yield is determined as follows: taking 1.0g of a sample to be detected, sequentially adding 20FPU (Fabry-Perot unit) cellulase, 20CBU beta-glucosidase and 0.03% sodium azide, and then supplementing a sodium acetate buffer solution until the liquid volume is 25.0mL to obtain a mixed solution; then, putting the mixed solution into a shaking table, controlling the conditions to be 200rpm and 50 ℃, and reacting for 3 days; after the reaction, the solution was filtered through a 0.45 μm filter and the reducing sugar yield was measured by the DNS method.

In another preferred embodiment, the steps of the denitrification test are as follows: placing the wood carbon source into a glass bottle containing water to be treated, then carrying out nitrogen aeration on the glass bottle, sealing after the aeration is finished, and placing the glass bottle in a biochemical incubator for culture at 25 ℃.

It should be understood that denitrification assays are routine in the art and will not be described in detail herein.

In other preferred embodiments, the wood carbon source is prepared according to the method for regulating and controlling the carbon release amount of the denitrifying wood carbon source based on the yield of the reducing sugar.

In other preferred embodiments, the application of the wood carbon source in the treatment of rural sewage by a biological denitrification method is further provided, the conformity between the carbon release amount of the wood carbon source and the utilization rate of denitrifying organisms is ensured, the problems of poor reaction effect caused by too small carbon release amount as a carbon source and secondary pollution caused by too much carbon release amount are avoided, and the long service life and the stable denitrification effect are maintained.

It should be understood that the difference in the species or region of the ground wood, which results in the difference in the original ground wood, may bring about the first equation, the second equation, and the variation in the first reducing sugar yield interval and the second reducing sugar yield interval, which can be adjusted according to the actual test results.

The foregoing method for controlling the carbon release amount of a denitrifying wood carbon source based on the yield of reducing sugar and the effect of a wood carbon source will be exemplarily tested and compared with specific examples and tests. Of course, the embodiments of the invention are not limited thereto.

[ example 1 ]

Set up equation

(1) Selecting 0.1-1.0mm poplar broken wood as raw material, weighing 6 parts, each 5.0g, adding 0.0, 0.03, 0.06, 0.10, 0.15 and 0.20g/g_{Carbon source}Ca (OH)₂Controlling the solid-liquid ratio to be 1:10, reacting for 24h under the conditions of 90 ℃ and 150rmp, repeatedly filtering, washing with water until the filtrate is neutral, and drying the solid sample at 60 ℃.

And (3) hydrolyzing the prepared sample with a special enzyme, adding 20FPU (fermented cellulose) and 20CBU (beta-glucosidase) into each gram of sample, carrying out hydrolysis reaction for 3d at 50 ℃, measuring the content of reducing sugar in the filtrate by using a DNS (domain name system) method, and calculating the yield of the reducing sugar, wherein the result is shown in Table 1.

TABLE 1 reducing sugar yield of crushed wood at calcium hydroxide dosing

Establishing a reducing sugar yield y₁And Ca (OH)₂Is added by x₁The curve is shown in FIG. 1, and is obtained by fitting to a linear rangeFirst equation y₁＝1251.5x₁+25.944(R²0.9542), and a first reducing sugar yield interval (31.3, 148.1)]148.1 is taken here because the reducing sugar yield tends to be flat as the amount of calcium hydroxide added increases from 148.1, and thus 148.1 can be considered as the maximum value.

(2) Selecting 0.1g Ca (OH) in the step (1)₂/g_{Carbon source}Treating the crushed wood at 90 ℃ for 24 hours, and then using C₂H₄O₃Carrying out secondary treatment, weighing 6 parts, each 5.0g, and respectively adding 0, 0.05, 0.1, 0.2, 0.3 and 0.5g/g_{Carbon source}C of (A)₂H₄O₃Controlling the solid-liquid ratio to be 1:10, reacting for 12h under the conditions of 50 ℃ and 150rmp, repeatedly filtering, washing with water and drying at 60 ℃ after the reaction is finished.

The prepared sample is hydrolyzed by the special enzyme, 20FPU cellulase and 20CBU beta-glucosidase are added into each gram of sample, the hydrolysis reaction is carried out for 3 days at the temperature of 50 ℃, the reducing sugar content in the filtrate is measured by a DNS method, and the yield of the second reducing sugar is calculated, and the result is shown in table 2.

TABLE 2 reducing sugar yield after secondary treatment of wood chips with peroxyacetic acid addition

Establishing a reducing sugar yield y₂And C₂H₄O₃Is added by x₂The curve is shown in fig. 2, and a second equation y is obtained by fitting to the linear range₂＝1344.4x₂+150.05(R²1) and a second reducing sugar yield interval of (148.1, 600.5)]Also, 600.5 is taken here because the reducing sugar yield tends to be flat as the amount of peracetic acid added increases from 600.5, and thus 600.5 can be considered as the maximum.

[ example 2 ]

Determination of target reducing sugar yield of wood carbon source under water environment to be detected

Simulating the environmental conditions of 100mg/L nitrate concentration, 25 ℃ temperature and 7 pH value, respectively adopting 5.0g of water

Treatment and C₂H₄O₃Treating the wood carbon source to carry out denitrification batch test. By testing, C₂H₄O₃The yield of reducing sugar for treating the wood carbon source is high and is 553.0mg/g_{Carbon source}Yield of untreated ligneous carbon source reducing sugar (31.3 mg/g)_{Carbon source}) 17.7 times of.

The specific process of the denitrification test is as follows: weighing 5.0g of wood carbon source, adding into 500mL glass bottle, adding 400mL simulated nitrate sewage, and adding NO of sewage₃^--N concentration of 100.0mg/L and pH 7; the sample bottle is aerated by nitrogen for 20min, sealed by a rubber plug and placed in a biochemical incubator for culture at 25 ℃.

Then, water samples were taken at 2 nd, 4 th, 6 th, 8 th, 10 th, 12 th and 15 th days after the culture, respectively, and NO was measured after filtration through a 0.45 μm filter₃^--N concentration, plotting a kinetic profile, selecting the data from 2 nd to 6 th with significant linear changes, fitting linearly to obtain an equation, see figure 3, and calculating the nitrate removal rate, untreated and C under both conditions according to the equation₂H₄O₃Nitrate removal rates for the treatment groups were 5.1 and 19.9mg/d, respectively, and thus, the target reducing sugar yield for the woody carbon source was 122.1mg/g under this ambient condition_{Carbon source}。

[ example 3 ]

Wood carbon source for determining carbon release amount required under water environment condition to be detected

The yield of the target reducing sugar of the ligneous carbon source obtained in example 2 was 122.1mg/g_{Crushed wood}According to the interval obtained in example 1, the yield of the target reducing sugar is within the range of the interval of the first reducing sugar, so that the calculation of the first equation yields Ca (OH) for the preparation of the ligneous carbon source₂The amount added was 0.077g Ca (OH)₂/g_{Carbon source}And reacting for 24 hours at the temperature of 90 ℃ to obtain the wood carbon source with the required carbon release amount.

Simulating the environmental conditions of nitrate concentration of 100mg/L, temperature of 25 ℃ and pH 7, using 5.0g of untreated and Ca (OH)₂And (3) processing the wood carbon source to carry out a verification test.

Weighing 5.0g of wood carbon source, adding into 500mL glass bottle, adding 400mL simulated nitrate sewage, and adding NO of sewage₃^--N concentration of 100.0mg/L and pH 7; the sample bottle is aerated by nitrogen for 20min, sealed by a rubber plug and placed in a biochemical incubator for culture at 25 ℃.

Sampling at 2 nd, 4 th, 6 th, 8 th, 10 th, 12 th and 15 th days after the culture to determine NO₃^-N concentration, plotted kinetic profile, and fitted linearly using data from 2 d to 6d, the results are shown in FIG. 4, and untreated and Ca (OH) are obtained from the fitted equation₂Nitrate removal rates in the treatment groups were 5.1 and 21.4mg/d, respectively, Ca (OH)₂The treated group increased to 4.2 times the untreated group.

As can be seen from the above, the yield of reducing sugar of the wood carbon source is regulated to 122.1mg/g under the water environment condition_{Crushed wood}When the method is used, the nitrate removal rate can reach 21.4mg/d, and the yield of reducing sugar on a woody carbon source is 553.0mg/g_{Crushed wood}In the process, the nitrate removal rate is 19.9mg/d, and the excessively high reducing sugar yield does not bring about a better nitrate removal rate, but causes carbon source waste, reduces the service life of the carbon source, brings about secondary pollution of a water environment, and is not beneficial to sewage treatment.

[ example 4 ]

Ca(OH)₂And C₂H₄O₃Mechanism for processing woody carbon sources

According to the results in table 1 and table 2, 7 kinds of wood carbon sources with large difference of reducing sugar yield are selected, the wood carbon sources are respectively untreated crushed wood and treated wood carbon sources with reducing sugar yield increased to 2.7, 3.6, 6.8, 9.1, 13.1 and 19.2 times respectively, neutral detergent dissolved components, hemicellulose content and cellulose content are measured by a van's washing method, ash content and water content are measured, and finally, the lignin content of each wood carbon source is calculated, and the result is shown in fig. 5. As can be seen from the figure, the lignin content and the reducing sugar yield are in a significant linear negative correlation relationship, the lignin content in the wood carbon source is gradually reduced along with the enhancement of the chemical treatment degree, the lignin removal rate is up to 89.6 percent, and the carbon release amount is gradually increased along with the reduction of the lignin content.

This is because the components in the woody carbon source are mainly lignin, cellulose and hemicellulose, the lignin is a main limiting factor for preventing the denitrifying organisms from utilizing the carbon source, and the cellulose and hemicellulose are effective solid components for the denitrifying organisms. The effective solid component generates reducing sugar after the action of biological enzyme. Thus, Ca (OH)₂And C₂H₄O₃The mechanism for treating the wood carbon source can be considered to be that the lignin content in the wood carbon source is changed by controlling the treatment conditions, so that the yield of reducing sugar is regulated and controlled, and further the carbon release amount of wood carbon and ammonia is regulated and controlled.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims (10)

1. A method for regulating and controlling carbon release amount of a denitrifying wood carbon source based on reducing sugar yield is characterized by comprising the following specific steps:

establishing a simulation test:

simulating the environmental conditions of the water body to be treated, establishing a water environment simulation system, and dividing the water body of the water environment simulation system into two equal parts;

performing denitrification test on a first wood carbon source to remove nitrate in the water environment simulation system, drawing a first nitrate concentration-time dynamics characteristic curve according to the test result, and testing the reducing sugar yield A of the first wood carbon source; wherein the first wood carbon source is untreated crushed wood;

the nitrate in the simulated water environment is removed from the other water body by adopting a second wood carbon source, and the concentration-time movement of the second nitrate is drawn according to the test resultA mechanical characteristic curve; wherein the second wood carbon source is C₂H₄O₃After treatment, the removal rate of lignin is more than or equal to 80 percent of broken wood;

determination of the desired reducing sugar yield B:

obtaining a first denitrification rate V under the condition of a first wood carbon source according to a first nitrate concentration-time dynamics characteristic curve₁Obtaining a second denitrification rate V under the condition of a second wood carbon source according to a second nitrate concentration-time dynamics characteristic curve₂；

The desired reducing sugar yield B satisfies formula (1):

regulating and controlling the carbon release amount of the wood carbon source:

if the value B is within the first reducing sugar yield interval, substituting the value B into a first equation;

wherein, the first reducing sugar yield interval and the first equation are obtained by the following method:

s1, placing equal amount of untreated wood chips in n Ca (OH) with different concentrations₂Reacting in a constant temperature shaking table, washing the reacted broken wood with water until the filtrate is neutral, and drying to obtain Ca (OH) with different concentrations₂The crushed wood after solution treatment was tested for reducing sugar yield C_iObtaining a first reducing sugar yield interval (A, C)]And establish Ca (OH)₂Obtaining a first equation after linear fitting according to a relation curve of the adding amount and the yield of corresponding reducing sugar; wherein, i is 1,2 … … n, C is C_iMaximum value of (1);

substituting the B value into the first equation to obtain the corresponding target Ca (OH)₂Concentration of and in the target Ca (OH)₂Under the condition of concentration, treating the untreated crushed wood according to the method of S1 to obtain a target wood carbon source of carbon release amount required by the water environment to be treated;

if the value B is within the second reducing sugar yield interval, substituting the value B into a second equation;

wherein, the second reducing sugar yield interval and the second equation obtaining method are as follows:

s21, placing equal amount of untreated wood chips in n Ca (OH) with different concentrations₂Reacting in a constant temperature shaking table, washing the reacted broken wood with water until the filtrate is neutral, and drying to obtain Ca (OH) with different concentrations₂The crushed wood after solution treatment was tested for reducing sugar yield C_iObtaining a first reducing sugar yield interval (A, C)]Determining the treated wood chips corresponding to the reducing sugar yield C as a third wood carbon source; wherein, i is 1,2 … … n, C is C_iMaximum value of (1);

s22, respectively placing an equal amount of third wood carbon source in m C with different concentrations₂H₄O₃In the solution, reacting in a constant temperature shaking table, after the reaction is finished, washing the reacted third wood carbon source with water until the filtrate is neutral, and drying to obtain C with different concentrations₂H₄O₃The crushed wood after the solution treatment is tested, and the reducing sugar yield D of a third wood carbon source after the treatment is respectively tested_jObtaining a second reducing sugar yield interval (C, D)]And building C₂H₄O₃Obtaining a second equation by linear fitting of a relation curve of the adding amount and the yield of the corresponding reducing sugar, wherein j is 1,2 … … m, and D is D_jMaximum value of (1);

substituting the value B into the second equation to obtain a corresponding target C₂H₄O₃Concentration of at the target C₂H₄O₃And under the condition of concentration, treating the third wood carbon source according to the method of S22 to obtain the target wood carbon source with the carbon release amount required by the water environment to be treated.

2. The method for controlling carbon release from a denitrifying wood carbon source based on reducing sugar yield as claimed in claim 1, wherein the crushed wood is aspen crushed wood.

3. The method for regulating and controlling the carbon release amount of a denitrifying wood carbon source based on reducing sugar yield according to claim 2, wherein the first equation is shown in formula (2):

y₁＝1251.5x₁+25.944 (2)

in the formula: x is the number of₁Is Ca (OH)₂Amount of addition, g/g_{Carbon source}；y₁Is added by an amount x₁Ca (OH)₂Reducing sugar yield of the treated crushed wood, mg/g_{Carbon source}。

4. The method for regulating and controlling the carbon release amount of a denitrifying wood carbon source based on reducing sugar yield according to claim 2, wherein the second equation is as shown in formula (3):

y₂＝1344.4x₂+150.05 (3)

in the formula: x is the number of₂Is C₂H₄O₃Amount of addition, g/g_{Carbon source}；y₂Is added by an amount x₂In mg/g of_{Carbon source}Reducing sugar yield in mg/g of the treated third woody carbon source_{Carbon source}。

5. The method for regulating and controlling carbon release amount of denitrifying wood carbon source based on reducing sugar yield of claim 2, wherein said first reducing sugar yield interval is (31.3, 148.1)]，mg/g_{Carbon source}。

6. The method for regulating and controlling carbon release amount of denitrifying wood carbon source based on reducing sugar yield of claim 2, wherein said second reducing sugar yield interval is (148.1, 600.5)]，mg/g_{Carbon source}。

7. The method for regulating carbon release amount of a denitrifying wood carbon source based on reducing sugar yield according to claim 1 or 2, wherein in said steps S1 and S21, the treatment conditions of the crushed wood are as follows: crushed wood and Ca (OH)₂The solid-liquid ratio of the solution is 1:10, the temperature of a constant temperature shaking table is 90 ℃, the rotating speed is 150rpm, the reaction time is 24h, and the drying temperature is 60 ℃.

8. According to claim 1 or 2The method for regulating and controlling the carbon release amount of the denitrifying wood carbon source based on the yield of reducing sugar is characterized in that in the step S22, a third wood carbon source and C are mixed₂H₄O₃The solid-liquid ratio of the solution is 1:10, the temperature of a constant temperature shaking table is 50 ℃, the rotating speed is 150rpm, the reaction time is 12h, and the drying temperature is 60 ℃.

9. A wood carbon source, which is prepared by the method for regulating and controlling the carbon release amount of the denitrifying wood carbon source based on the reducing sugar yield according to any one of claims 1 to 8.

10. Use of the wood-based carbon source of claim 9 in the biological denitrification treatment of rural sewage.

Images