CN114720586B

CN114720586B - Method for evaluating influence of anions on anaerobic digestion of sludge

Info

Publication number: CN114720586B
Application number: CN202210229837.8A
Authority: CN
Inventors: 胡承志; 哈萨尔
Original assignee: Research Center for Eco Environmental Sciences of CAS
Current assignee: Research Center for Eco Environmental Sciences of CAS
Priority date: 2022-03-09
Filing date: 2022-03-09
Publication date: 2023-03-21
Anticipated expiration: 2042-03-09
Also published as: CN114720586A

Abstract

The invention provides a method for evaluating the influence of anions on anaerobic digestion of sludge, and relates to the field of sludge treatment. The method comprises the following steps: anaerobic digestion sludge and activated sludge are added into a reactor of a full-automatic methane potential testing system; adding a solution containing anions into the sludge in the reactor to serve as an experimental group, adding an equal amount of ultrapure water into the sludge in the reactor to serve as a control group, and only adding the sludge into the reactor to serve as a blank group; starting each reactor to carry out anaerobic digestion reaction on the sludge until the reaction is complete; obtaining at least one of the following indicators to evaluate the effect of the anions on anaerobic digestion of the sludge: the methane production amount of the anaerobic digestion reaction, the anion concentration of the supernatant after the sludge centrifugation, the ammonia nitrogen concentration of the supernatant after the sludge centrifugation, the microbial diversity level of the sludge before and after the anaerobic digestion reaction, and the microbial composition of the sludge before and after the anaerobic digestion reaction.

Description

Method for evaluating influence of anions on anaerobic digestion of sludge

Technical Field

The invention relates to the field of sludge treatment, in particular to a method for evaluating the influence of anions on anaerobic digestion of sludge.

Background

At present, the method for treating the excess sludge can be mainly divided into a physical method, a chemical method, aerobic bioleaching, anaerobic digestion and the like. The anaerobic digestion of the sludge takes the activated sludge as a substrate, and achieves the processes of degrading organic matters in the activated sludge, reducing the water content of the sludge and generating the methane through the five steps under the anaerobic condition. Nitrate or nitrite with higher concentration can be produced in the process of removing ammonia nitrogen by nitrification in municipal sewage plants, and in addition, industrial enterprises can also discharge nitrate containing

Nitrite radical

Sulfate radical

With chlorate radical

And the wastewater of typical anions enters a municipal pipe network and finally enters a sewage plant. When the surplus sludge enters the anaerobic digestion reactor, the above anions may enter the sludge treatment system to affect anaerobic digestion. How to evaluate the influence of anions on the anaerobic digestion of sludge is not reported in the prior art.

Disclosure of Invention

Accordingly, the present invention aims to provide a method for evaluating the effect of anions on anaerobic digestion of sludge.

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

the invention provides a method for evaluating the influence of anions on anaerobic digestion of sludge, which comprises the following steps:

(1) Anaerobic digestion sludge and activated sludge are added into a reactor of a full-automatic methane potential testing system;

(2) Adding a solution containing anions into the sludge in the reactor to serve as an experimental group, adding equal amount of ultrapure water into the sludge in the reactor to serve as a control group, and only adding sludge into the reactor to serve as a blank group;

(3) Starting each reactor to carry out anaerobic digestion reaction of sludge until the reaction is complete;

(4) Obtaining at least one of the following criteria to evaluate the effect of the anions on anaerobic digestion of the sludge: the methane yield of the anaerobic digestion reaction, the anion concentration of the supernatant after the centrifugation of the sludge, the ammonia nitrogen concentration of the supernatant after the centrifugation of the sludge, the microbial diversity level of the sludge before and after the anaerobic digestion reaction, and the microbial composition of the sludge before and after the anaerobic digestion reaction.

Further, the anion includes

At least one of (a).

Further, in the step (1), according to the proportion of the volatile solid of the anaerobic digestion sludge and the active sludge being 3:2 adding the anaerobic digestion sludge and the activated sludge, wherein the total weight of the anaerobic digestion sludge and the activated sludge is 400g.

Further, in the step (2), the amounts of the solution containing anions and ultrapure water added were each 5mL, and the anion concentrations in the reactor were adjusted to 2mmol/L, 4mmol/L and 8mmol/L, respectively.

Further, in the step (3), nitrogen is introduced into the reactor for 2min before each reactor is started; the rotating speed of a stirring rod of the reactor is adjusted to be 100rpm/min, the stirring start interval is 60s, the temperature in the reactor is 37 ℃, and the reactor continuously operates for 18 days.

Further, in the step (3), adding 3mol/L NaOH solution into the gas adsorption unit of the full-automatic methane potential testing system during the reaction process to adsorb acid gas generated by anaerobic digestion reaction of sludge.

Further, in the step (4), acquiring the methane production amount of the anaerobic digestion reaction by a data processing unit of the full-automatic methane potential testing system.

Further, in the step (4), the method for detecting the anion concentration in the supernatant after the sludge centrifugation comprises the following steps: centrifuging the sludge at 4000rpm and 4 ℃ for 10min; taking the supernatant, using C ₁₈ Removing organic matters and impurities by using a column; using ultrapure water to mix C ₁₈ Diluting the supernatant after column filtration by 10 times, filtering with 0.45 μm filter membrane, and measuring the content of the supernatant by ion chromatography

And (4) concentration.

Further, in the step (4), the method for detecting the ammonia nitrogen concentration in the supernatant after the sludge centrifugation comprises the following steps: centrifuging the sludge at 4000rpm and 4 ℃ for 10min; and taking the supernatant, diluting the supernatant by 10 times with ultrapure water, and measuring the ammonia nitrogen concentration in the supernatant by adopting an ammonia gas sensitive electrode method.

Further, in the step (4), the microbial diversity level in the sludge is evaluated through an ACE diversity index, an observed specific diversity index, a pedigree diversity index and microbial flora diversity; the microbial composition in the sludge was evaluated by the relative abundance of microbial communities at different levels.

The technical scheme of the invention has the following advantages:

the invention provides a method for evaluating the influence of anions on anaerobic digestion of sludge, which utilizes a full-automatic methane potential testing system, reflects the influence of anions on the anaerobic digestion of the sludge by adding a solution containing the anions into the sludge and taking the methane production amount of anaerobic digestion reaction, the anion concentration and ammonia nitrogen concentration in supernatant after the centrifugation of the sludge, the microbial diversity level in the sludge before and after the anaerobic digestion reaction, microbial composition and the like as evaluation indexes so as to provide reference for how to accelerate the anaerobic digestion of the sludge, shorten the retention time of a reactor and the like in the subsequent sludge treatment work.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic representation of the reactor introduction in the example of the invention

Simulating a change chart of the methane production during 18 days of anaerobic digestion reaction;

FIG. 2 is a diagram of the reactor introduction in the example of the invention

FIG. 3 is a diagram of the reactor introduction in an example of the invention

A change chart of the methane production amount in the 18-day process of the simulated anaerobic digestion reaction;

FIG. 4 is a diagram of the reactor introduction in an example of the invention

FIG. 5 shows the different anion species and concentration pairs in the sludge supernatant after reaction in the example of the present invention

Influence result graph of (2);

FIG. 6 shows the different anion species and concentration pairs in the sludge supernatant after reaction in the example of the present invention

Influence result graph of (2);

FIG. 7 is a graph showing the effect of different anion species and concentrations on ammonia nitrogen in the sludge supernatant after the reaction in the example of the present invention;

FIG. 8 is a graph showing the effect of different anion species and concentrations on the ACE diversity index of microorganisms in sludge after reaction in the example of the present invention;

FIG. 9 is a graph showing the effect of different anion species and concentrations on the microbial observed species diversity index in the sludge after the reaction in the example of the present invention;

FIG. 10 is a graph showing the effect of different anion species and concentrations on the microbial lineage diversity index in the sludge after the reaction in the example of the present invention;

FIG. 11 is a NMDS analysis graph of sludge after reaction for different anion species and concentrations in the examples of the present invention;

FIG. 12 is a graph of PCA analysis of sludge after reaction for different anion species and concentrations in an example of the present invention;

FIG. 13 is a graph of the relative abundance of sludge microbial communities at the gate level after introduction of different species and concentrations of anions in accordance with an example of the present invention;

fig. 14 is a graph of the relative abundance of sludge microbial communities at the genus level after introduction of different species and concentrations of anions in an example of the present invention.

Detailed Description

The following examples are provided to further understand the present invention, not to limit the scope of the present invention, but to provide the best mode, not to limit the content and the protection scope of the present invention, and any product similar or similar to the present invention, which is obtained by combining the present invention with other prior art features, falls within the protection scope of the present invention.

The examples do not show the specific experimental steps or conditions, and can be performed according to the conventional experimental steps described in the literature in the field. The raw materials or equipment used are all conventional products which can be obtained commercially, including but not limited to the raw materials or equipment used in the examples of the present application.

Examples

This example provides an evaluation anion

The method for influencing the anaerobic digestion of the sludge specifically comprises the following operations:

1. sludge sample

The sludge sample is taken from a municipal sewage plant in Beijing, and the sewage treatment process is (A) ² O), the sludge treatment process is anaerobic digestion. And respectively taking anaerobic digestion sludge and activated sludge samples from the anaerobic digestion tank and the secondary sedimentation tank unit, transferring the samples to a laboratory within 2 hours after the samples are taken in a factory, and storing the samples in an environment at 4 ℃ in a dark place.

The main physicochemical characteristics of anaerobically digested sludge and activated sludge are shown in table 1:

TABLE 1 sludge physicochemical indices used in the experiments

Sample (I)	pH	TSS(g/L)	VSS(g/L)
				Activated sludge	6.56±0.2	19.57±0.7	17.36±0.4
Anaerobic digestion of sludge	7.68±0.1	55.64±0.5	24.62±0.3

2. Reagent

The anion solution introduced during anaerobic digestion of sludge is sodium nitrate, sodium nitrite, sodium chlorate and sodium sulfate; sodium hydroxide and thymolphthalein used in the gas adsorption unit are analytical pure grade medicines produced by the national medicine group; standard solution required for detection: (

Ammonia nitrogen, etc.) were purchased from the national standards research center and formulated.

3. Instrumentation and equipment

The pH of the sludge was measured using a 110p-01A STAR pH meter (ThermoFisher, co., USA); the anaerobic digestion reaction of the sludge is operated by an Automatic methane potential test system II (AMPTS-II) from Bioprocess Control (Sweden); centrifuging the sludge by a high-speed refrigerated centrifuge (SIGMA 3-16 PK); the concentration of anions in the centrifuged sludge supernatant is measured by an ICS-5000 type ion chromatograph (ThermoFisher, co., USA), the concentration of ammonia nitrogen is measured by a Raymond PNH3-3 ammonia-sensitive electrode (Shanghai, raymond), and a freeze dryer (FD-1A-50, beijing Bo Yi kang laboratory instruments Co., ltd.) is adopted in the drying process.

AMPTS-II is a continuous anaerobic reactor with adjustable stirring speed and direction, and the whole system can be divided into a reaction unit (reactor), a gas adsorption unit, a data processing unit and the like. When the equipment is in operation, gas generated in the reactor is discharged through a silica gel hose connecting the reactor and the gas adsorption unit, and then passes through a sodium hydroxide solution (3 mol/L) in the gas adsorption unit, wherein CO possibly generated in the reactor at the moment ₂ 、H ₂ And the acidic gases such as S and the like are adsorbed by the sodium hydroxide solution, so that the interference of the acidic gases on the measurement of the methane yield of the reaction is eliminated. And gas which is not absorbed by the sodium hydroxide solution is discharged through a silica gel hose and enters a data processing unit, the gas valve soaked in deionized water is used for recording the methane yield of each group of reactors, and finally information such as the accumulated methane yield and the total methane yield per hour or per day is provided.

4. Method of operation

(1) Adding anaerobic digestion sludge and activated sludge

According to the proportion of Volatile Solids (VS) of anaerobic digestion sludge to active sludge of 3:2 adding anaerobic digestion sludge and activated sludge into a reactor of the full-automatic methane potential testing system, wherein the total weight of the anaerobic digestion sludge and the activated sludge is 400g.

(2) Adding a solution containing anions

Respectively adding 5mL of sodium nitrate, sodium nitrite, sodium chlorate or sodium sulfate as an experimental group into the sludge in different reactors, and analyzing and introducing the same salt solution, changing the introduction concentration of anions to study the influence of anions with different concentrations on the anaerobic digestion reaction of the sludge, so that the concentrations of the corresponding anions in the reactors are respectively 2mmol/L, 4mmol/L and 8mmol/L; adding ultrapure water into the sludge in the reactor in the same amount as a control group; only sludge was added to the reactor as a blank set.

(3) Simulating sludge anaerobic digestion reaction

And (3) rapidly sealing after the sludge is mixed, and introducing nitrogen into each reactor for 2min through a silica gel hose to ensure that oxygen in the reactor is completely discharged, so that the anaerobic condition required for anaerobic digestion reaction is achieved in the reactor.

Starting each reactor to carry out anaerobic digestion reaction of sludge, adjusting the rotating speed of a stirring rod of the reactor to be 100rpm/min, adjusting the stirring starting interval to be 60s, controlling the temperature in the reactor to be 37 ℃, continuously operating the reactors for 18 days, and displaying that the methane yield of all the reactors in a data processing unit approaches to 0, and considering that the methane yield of the anaerobic digestion reaction reaches saturation and the gas production data is not increased any more.

(4) Obtaining an evaluation index

a. Amount of methane produced

And reading the methane production amount of the anaerobic digestion reaction through a data processing unit of the full-automatic methane potential testing system.

b. In the supernatant of sludge

Concentration of

After the reaction is finished, taking out a sludge sample, placing the sludge sample in a refrigerated centrifuge, and centrifuging for 10min at the conditions of 4000rpm and 4 ℃; taking the supernatant, using C ₁₈ Removing organic matters and impurities by using a column; using ultrapure water to mix C ₁₈ Diluting the supernatant after column filtration by 10 times, filtering with 0.45 μm filter membrane, and measuring the content of the supernatant by ion chromatography

And (4) concentration.

c. Ammonia nitrogen concentration in sludge supernatant

After the reaction is finished, taking out a sludge sample, placing the sludge sample in a refrigerated centrifuge, and centrifuging for 10min at the conditions of 4000rpm and 4 ℃; and taking the supernatant, diluting the supernatant by 10 times with ultrapure water, and measuring the ammonia nitrogen concentration in the supernatant by adopting an ammonia gas sensitive electrode method.

d. Microbial diversity levels, microbial flora diversity and microbial composition

After the reaction, the sludge sample was taken out and freeze-dried, and then sent to the Highestan Biotech Co., ltd for high-throughput sequencing of 1696 rRNA V3 and V4 regions together with the unreacted mixed sludge sample (cryopreservation). The ACE diversity index, the observed specific diversity index, the pedigree diversity index, the microbial flora diversity, the relative abundance of microbial communities at different levels and the like are obtained by processing sequencing data.

(5) Analysis of results

a. Effect of anion type and concentration on the amount of methane produced by anaerobic digestion

Different types and concentrations of anions are introduced into a sludge sample

Thereafter, the amount of methane produced in the reactor over the course of 18 days simulating the anaerobic digestion reaction is shown in FIGS. 1 to 4.

As shown in FIG. 1, 2mmol/L, 4mmol/L and 8mmol/L NaNO were introduced ₃ The cumulative methane production was higher than that of the control group to which no anion was introduced. The control group has a cumulative methane production of 409.5mL and 2mmol/L

The amount of the generated methane is 414.2mL; is further increased

The adding amount is increased to 4mmol/L, and the methane production amount is correspondingly increased to 422.9mL; the methane yield is not obviously increased any more when the methane yield is continuously increased to 8mmol/L.

As shown in FIG. 2, a lower concentration of Na ₂ SO ₄ The introduction of Na with high concentration shows certain promotion effect on anaerobic digestion gas production ₂ SO ₄ The introduction of the inhibitor inhibits anaerobic digestion gas production. Introducing 2mmol/L of

When the amount of accumulated methane produced increased to 438.7mL, the group with the highest methane production was found in the experimental group and the control group. But follow by

The introduction concentration was increased continuously to 4mmol/L andwhen the concentration of the methane is 8mmol/L, the methane yield of anaerobic digestion of the sludge is respectively 402.3mL and 370.8mL, the methane yield is lower than that of a control group, and 8mmol/L is introduced

The time for producing methane is shortened, and the sludge stops producing methane on the 10 th day.

As shown in FIG. 3, 2mmol/L of

When the amount of the accumulated methane is increased to 421.8mL from 409.5mL of the amount of the accumulated methane generated by the control group; is further enlarged

To 4mmol/L and 8mmol/L, the cumulative methane production was reduced to 405.8mL and 382.4mL, respectively. With introduction of Na ₂ SO ₄ In contrast, in sludge

The gas production rate at the early stage is obviously reduced when the concentration is increased. 8 days before the start of the reaction, the control group was introduced with 2mmol/L, 4mmol/L, 8mmol/L

The cumulative methane production after this time was 405.1mL, 388.2mL, 366.8mL and 277.46mL, respectively.

As shown in FIG. 4, naClO is introduced ₃ Inhibiting the anaerobic digestion of sludge to produce gas

The more pronounced the increase in suppression effect. Specifically, introduce

The accumulated methane production amount of the anaerobic digestion sludge is 409.5mL, 393.3mL, 363.9mL and 353.0mL when the concentration is 0mmol/L, 2mmol/L, 4mmol/L and 8mmol/L respectively.

NaClO under the various experimental conditions described above ₃ When the dosage is 8mmol/L, the anaerobic digestion biogas production is shownMost pronounced inhibitory effect, while Na ₂ SO ₄ The most obvious gas production promoting effect is shown when the concentration is 2 mmol/L.

b. The species and concentration of anions are in the supernatant of the sludge after the reaction

And

influence of (2)

As shown in FIG. 5, different concentrations of NaNO were introduced before anaerobic digestion reaction ₃ The sludge of (2), the supernatant after the reaction

Concentration and no introduction of NaNO ₃ In the supernatant of the sludge

The concentrations are similar.

As shown in FIG. 6, in the supernatant of the sludge after the reaction

The concentration (22-75 mg/L) is far lower than that introduced before the reaction

The concentration (192-768 mg/L). Thus it is considered that the sludge is introduced

Is reduced.

c. Influence of anion species and concentration on ammonia nitrogen in sludge supernatant after reaction

As shown in FIG. 7, the ammonia nitrogen concentration of the sample ranges from 2.5 g/L to 9.4g/L because of the longer retention time. Introducing different concentrations into the sludge

When the ammonia nitrogen concentration is in the range of 2.5-3.0 g/L, 3.0-3.5 g/L, 3.0-5.0 g/L and 7.0-9.6 g/L in sequence. Introduced into the sludge

And

when the concentration is increased, the increase amplitude of the ammonia nitrogen concentration in the supernatant is smaller and is close to the ammonia nitrogen concentration (2.6 g/L) of the control group; in the sludge

And

when the concentration is increased, the ammonia nitrogen concentration in the supernatant is increased to a larger extent and is obviously higher than the ammonia nitrogen concentration of a control group. Due to introduction of

Does not lead to an increase in the ammonia nitrogen concentration in the sludge supernatant, and is therefore considered to be introduced

Participates in anaerobic digestion reaction, is absorbed by microorganisms in anaerobic sludge and is used for growth and metabolism.

The relationship between ammonia nitrogen and methane production in different reactors was compared with FIGS. 1-4 and FIG. 7. As the ammonia nitrogen concentration in the sludge supernatant increases, the methane production in the corresponding anaerobic digestion reaction is inhibited. Introducing 4mmol/L and 8mmol/L of the mixture before anaerobic digestion reaction

When the ammonia nitrogen concentration of the sludge supernatant is higher than 9g/L, the ammonia nitrogen concentration is similar to 9.1g/L of the ammonia nitrogen concentration of the sludge supernatant of a blank group without carbon sources. Introduction of

The concentration of ammonia nitrogen in the sludge is increased, and the high-concentration ammonia nitrogenChanges the survival conditions of microorganisms and is the reason that the gas production of the anaerobic digestion reaction of the sludge is inhibited.

d. Influence of anion species and concentration on sludge microbial diversity

Fig. 8-10 show the level of alpha diversity of sludge microorganisms after introduction of different species and concentrations of anions. As can be seen from the figure, introduce

Higher values of ACE, observed species and lineage diversity index, while

Lower values of ACE, observed speces and lineage diversity index of; the introduction of anions all affect the level of alpha diversity of the microorganism to varying degrees. Specifically, different concentrations are introduced into the sludge system

And

the ACE values are 998 + -54, 889 + -49, 872 + -45 and 1032 + -94 in sequence, the observed species values are 882 + -66, 761 + -40, 733 + -26 and 821 + -47 in sequence, and the pedigree diversity index is 94 + -5, 83 + -4, 83 + -3 and 88 + -3 in sequence. The higher the numerical value of indexes such as ACE, observed species, pedigree diversity index and the like, the higher the microbial community diversity is. The above results show that the introduction

And

make the microbial population of the sludge after anaerobic digestion of the sludge richer, and

and

the number of microbial species in the sludge is made lower.

The differences of microbial flora of the sludge after anaerobic digestion by introducing different types and concentrations of anions are researched by adopting a non-metric multidimensional scaling analysis (NMDS) and Principal Component Analysis (PCA) method of beta diversity, and the results are shown in FIGS. 11 and 12.

As can be seen from FIG. 11, 8mmol/L of the polymer was introduced

The distance between the probe and all samples is farthest, 2mmol/L and 4mmol/L are introduced

And the distance between the sample and other samples is longer. Thus, 8mmol/L of

The method is obviously different from the community structures of other groups, and 2mmol/L and 4mmol/L are introduced

There was a large difference in colony structure between the group (2) and the remaining groups.

As shown in fig. 12, the PCA analysis results show the difference in PC1 axis and PC2 axis when different anions were introduced. Similar to the NMDS results, 8mmol/L was introduced

The distance between the probe and all samples is farthest, and 4mmol/L is introduced

2mmol/L

And the distance between the sample and other samples is longer. But 2mmol/L, 4mmol/L, 8mmol/L were introduced

The time distance is small. As in NMDSAnalysis, introduction of 8mmol/L

The microbial community structure is obviously different from other groups, and 4mmol/L is introduced

2mmol/L

There was a large difference in colony structure between the hour and the remaining groups.

Results of beta diversity demonstrate, incorporation

Has little influence on microbial community, and is introduced

The change of the anion concentration can cause obvious difference of community structure after anaerobic digestion of the sludge.

e. Effect of anion species and concentration on sludge microbial community composition

By amplicon sequencing, a total of 1902 OTUs were obtained from 15 samples.

As shown in FIG. 13, on the phylum level, mythidia, proteobacteria, bacteroides, actinomyces, campylobacter, nitrospira, atribacteria, actinomyces, and Chorispora are the top nine categories of relative abundance. Compared with the unreacted sludge, the microbial composition of the sludge after the anaerobic digestion reaction is obviously changed, mainly manifested by the reduction of the relative abundance of Proteus and Nitrospira and the increase of the relative abundance of Steinerachariella and Calleromyces SOFTWARIANA. The unreacted sludge sample is a mixture of anaerobic digested sludge and activated sludge, the relative abundance of proteobacteria and nitrification-related bacteria is high, in the anaerobic fermentation process, the relative abundance of firmicutes as phyla adapting to anaerobic digestion and generating Volatile Fatty Acid (VFA) rapidly rises, the relative abundance of firmicutes also rises, and the nitrifying spirillum and the like are reduced due to the change of the nutritional environment.

As shown in fig. 13, the microbial community structure at the level of all the cultured sludge phyla was analyzed to obtain firmicutes, proteobacteria and bacteroidetes as the first three categories of relative abundance in the anaerobic digested samples, which were about 43.5-77.9%, 5.5-23.6% and 3.5-12.3%, respectively. Introducing 4mmol/L

The relative abundance of bacteroides in the sludge is the highest, and 8mmol/L is introduced

When the sludge is used, the relative abundance of proteobacteria in the sludge is highest. The relative abundance of Proteobacteria and Bacteroides is introduced

And

respectively, the relative abundance of the firmicutes is lower than that of the control group, and 8mmol/L is introduced

The time is the lowest. The relative abundance of the firmicutes is introduced at 2mmol/L

Is highest and follows

The concentration increases and decreases.

The control group and the first ten microorganisms of the sludge at genus level after introduction of different kinds and concentrations of anions were further analyzed, and as shown in fig. 14, the genera of firmicutes (fastiosilica), (Lactobacillus), and proteobacteria (archaebacteria) were the first three genera of relative abundance, which were about 5.2 to 15.6%, 2.0 to 7.5%, and 0 to 7.8%, respectively.

Introducing 2mmol/L, 4mmol/L and 8mmol/L

When the concentration of Dechloromonas is 1.8%, 2.2% and 3.6%, respectively, 8mmol/L of the catalyst is introduced

The relative abundance of Thauera was 2.5%. Dechloromonas and Thauera have the capability of denitrifying denitrification. Thus, in the sludge

The concentration increase improves the sludge denitrification capability.

The relative abundance of Arcobacter in the sludge is introduced into the sludge in a range of 2mmol/L, 4mmol/L and 8mmol/L

The amounts of the components are respectively 1.9%, 3.9% and 7.8%.

Fastidiosipila and Lactobacillus are capable of organically decomposing organic acids. Introducing 2mmol/L and 4mmol/L sludge

When the relative abundance of Fastidiosipila is reduced to 4.1 percent and 5.4 percent respectively, and the relative abundance of Lactobacillus is introduced to 2mmol/L and 4mmol/L

And tends to 0. Significantly lower than the relative abundance of Fastiliosipila and Lactobacillus in the control group. 2mmol/L and 4mmol/L are introduced

Resulting in the increase of ammonia nitrogen concentration in the sludge, and inhibits FaThe growth of stidiosipila and Lactobacillus affects the rate of hydrolytic acidification reactions, and thus anaerobic digestion reactions are inhibited. In addition, 8mmol/L was introduced

Although Lactobacillus is not inhibited, methylobacter using methane as a carbon source is promoted; resulting in the introduction of 8mmol/L

When the amount of methane produced by anaerobic digestion reaction is the lowest.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications derived therefrom are intended to be within the scope of the invention.

Claims

1. A method for evaluating the effect of an anion on anaerobic digestion of sludge, wherein the anion is

The method comprises the following steps:

(2) Adding a solution containing anions into the sludge in the reactor to serve as an experimental group, adding an equal amount of ultrapure water into the sludge in the reactor to serve as a control group, and only adding the sludge into the reactor to serve as a blank group;

(3) Starting each reactor to carry out sludge anaerobic digestion reaction until the reaction is complete, wherein nitrogen is introduced into the reactor for 2min before each reactor is started; adjusting the rotating speed of a stirring rod of the reactor to be 100rpm/min, the stirring start interval to be 60s, the temperature in the reactor to be 37 ℃, and continuously operating the reactor for 18 days;

(4) The following indices were obtained to evaluate the effect of anions on anaerobic digestion of sludge: the method comprises the following steps of evaluating the methane production amount of anaerobic digestion reaction, the anion concentration of supernatant after sludge centrifugation, the ammonia nitrogen concentration of supernatant after sludge centrifugation, the microbial diversity level of sludge before and after anaerobic digestion reaction and the microbial composition of sludge before and after anaerobic digestion reaction, wherein the microbial diversity level of sludge is evaluated through an ACE diversity index, an observedspecies diversity index, a pedigree diversity index and microbial flora difference; the microbial composition in the sludge was assessed by the relative abundance of microbial communities at different levels.

2. The method for evaluating the effect of anions on anaerobic digestion of sludge according to claim 1, wherein in step (1), the ratio of volatile solids of anaerobic digested sludge to activated sludge is 3:2 adding the anaerobic digestion sludge and the activated sludge, wherein the total weight of the anaerobic digestion sludge and the activated sludge is 400g.

3. The method for evaluating the influence of anions on anaerobic digestion of sludge according to claim 1, wherein in the step (2), the amount of the solution containing anions and the amount of ultrapure water added are both 5mL, and the anion concentrations in the reactor are adjusted to 2mmol/L, 4mmol/L and 8mmol/L, respectively.

4. The method for evaluating the influence of anions on anaerobic digestion of sludge according to claim 1, wherein in the step (3), 3mol/L NaOH solution is added into the gas adsorption unit of the fully automatic methane potential testing system during the reaction process to adsorb acid gas generated by anaerobic digestion reaction of sludge.

5. The method for evaluating the influence of anions on the anaerobic digestion of sludge according to claim 1, wherein in the step (4), the methane production amount of the anaerobic digestion reaction is obtained by a data processing unit of the full-automatic methane potential testing system.

6. The method for evaluating the effect of anions on anaerobic digestion of sludge according to claim 1, wherein in the step (4), the method for detecting the anion concentration in the supernatant after the sludge centrifugation comprises: centrifuging the sludge at 4000rpm and 4 ℃ for 10min; taking the supernatant, using C ₁₈ Removing organic matters and impurities by using a column; using ultrapure water to mix C ₁₈ Diluting the supernatant after column filtration by 10 times, filtering with 0.45 μm filter membrane, and measuring the content of the supernatant by ion chromatography

And (4) concentration.

7. The method for evaluating the influence of anions on the anaerobic digestion of sludge according to claim 1, wherein in the step (4), the method for detecting the ammonia nitrogen concentration in the supernatant after the sludge centrifugation comprises the following steps: centrifuging the sludge at 4000rpm and 4 ℃ for 10min; and taking the supernatant, diluting the supernatant by 10 times with ultrapure water, and measuring the ammonia nitrogen concentration in the supernatant by adopting an ammonia gas sensitive electrode method.