CN106348427A - Method for assessing whether activated sludge adapts to new environment or not based on breath graph - Google Patents

Abstract

The invention discloses a method for assessing whether activated sludge adapts to a new environment based on a respiration pattern, comprising: 1) analyzing the respiration pattern of the activated sludge in a sewage treatment plant to obtain two sections of the respiration pattern DO-t curve; 2) analyzing each The DO-t curve of the segmental respiration spectrum is fitted to obtain its slope, and the endogenous respiration rate OURe, and the total respiration rate OURt after adding nitrogen source and carbon source are obtained; 3) the OURe/OURt-t curve is obtained; 4) according to the OURe/OURt-t curve, The change trend of the OURt-t curve is used to evaluate whether the activated sludge adapts to the new environment. The curve shows a trend of rising first and then stabilizing or rising and then falling, which indicates that the activated sludge can adapt to the new environment; if the curve still rises after changing the environmental conditions for a week, That is, it showed a continuous upward trend, indicating that activated sludge could not adapt to the new environment. According to the judgment of the trend of the endogenous respiration ratio (OURe/OURt) of the activated sludge, the invention simply and effectively evaluates whether the activated sludge adapts to the new environment.

Description

A method for assessing the suitability of activated sludge to a new environment based on respiration patterns

technical field

The invention belongs to the field of sewage treatment and relates to a method for evaluating whether activated sludge adapts to a new environment by analyzing activated sludge respiration patterns.

Background technique

Activated sludge process is currently the most widely used sewage treatment technology, accounting for more than 90% of urban sewage treatment processes and about 50% of industrial wastewater treatment processes. The core of the activated sludge process is activated sludge. The effect of sewage and wastewater treatment depends on the characteristics of the microorganisms in the activated sludge. However, changes in environmental conditions often affect the changes in the structure and activity of activated sludge, thereby affecting sewage and wastewater. processing effect. Therefore, it is particularly important to understand the tolerance of activated sludge to environmental changes, or to evaluate whether activated sludge can adapt to the new environment.

At present, a large number of studies mainly focus on the determination of the activity of activated sludge, but there are few methods to evaluate whether activated sludge can adapt to the new environment. There are many methods for measuring activated sludge activity, including activated sludge ATP content determination method, activated sludge oxygen consumption rate determination method, and dehydrogenase activity method. The ATP content in activated sludge is relatively stable, and the growth rate of organisms will not affect the ratio of ATP/living biomass, and ATP will disappear immediately after the organisms die. The concentration of ATP is directly related to the biomass of activated sludge, and also directly related to the metabolic rate of activated sludge microorganisms. Highly active activated sludge, microorganisms have a high metabolic rate, and there is a high concentration of ATP in the cells; the activated sludge oxygen consumption rate (OUR) can provide basic information on the activity of activated sludge, when the OUR value is 20 ~ 40g O2/( kgVSS·h), it indicates that the activated sludge is active, and if the OUR value is 5-10g O2/(kgVSS·h), its value is low, indicating that the activity of the activated sludge is poor; the dehydrogenase activity method uses dehydrogenase Hydrogenase catalyzes the dehydrogenation of organic matter, and then the hydrogen is transferred to a specific hydrogen acceptor (in aerobic treatment, the last hydrogen acceptor is molecular oxygen), and the biological treatment of wastewater is to use the action of microorganisms to make the organic matter in wastewater Decomposed into simpler compounds, therefore, the activity of dehydrogenase also represents the activity of activated sludge. However, all of the above are the determination of the activity of activated sludge, and there is no direct method to evaluate whether activated sludge can adapt to the new environment.

In addition, in the existing small and medium-sized sewage treatment plants, due to the lack of talents and equipment, it is impossible to simply and quickly check whether the activated sludge is activated under the changing conditions of the environment (such as: DO, temperature, pH, chemical agent addition, etc.) Ability to adapt to changes in the environment and make accurate assessments and judgments. Based on the above situation, it is an urgent technical problem to be solved in this field to propose a method, that is, to establish a simple and feasible method for evaluating whether the activated sludge can adapt to the new environment through the analysis of the breath pattern.

Contents of the invention

The purpose of the present invention is to provide a method for assessing whether activated sludge adapts to the new environment based on the respiration spectrum. The method utilizes the DO-t curve of activated sludge respiration spectrum obtained under aerobic conditions, obtains its slope by fitting, and then draws out A curve of OURe/OURt-t, from the changing trend of the OURe/OURt-t curve, accurately evaluates whether the activated sludge is suitable for the environment.

As a method to evaluate whether activated sludge can adapt to the environment, the test results of activated sludge in sewage plants show that: the method we invented to evaluate whether activated sludge can adapt to the new environment based on the respiration map can accurately and efficiently assess whether the activated sludge can adapt to the new environment. The environment is assessed.

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

1. a kind of method that assesses whether activated sludge adapts to new environment based on respiration pattern that the embodiment of the present invention provides, the method may further comprise the steps:

1) Take the activated sludge from the sewage treatment plant, wash the activated sludge multiple times with a buffer solution, and fully aerate the activated sludge to enter the endogenous breathing state;

2) After the activated sludge enters the state of endogenous respiration, it is fully stirred to obtain the DO-t curve of the first section of the respiration map, and the slope is obtained by fitting, which is the endogenous respiration rate OURe of the activated sludge;

3) Add a nitrogen source and a carbon source to the activated sludge in step 2), then fully aerate until the dissolved oxygen DO reaches more than 7mg/L, and fully stir to obtain another section of the breath spectrum DO-t curve, and obtain its slope by fitting , which is the total respiration rate OURt;

4) Repeat steps 1)-3) to obtain the time-varying endogenous respiration rate OURe value and the total sludge respiration rate OURt value respectively;

5) Use the OURe/OURt ratio to draw a curve about time t, and evaluate whether the activated sludge adapts to the new environment according to the change trend of the OURe/OURt-t curve. If the curve rises first and then stabilizes or first rises and then declines, it indicates the activity The sludge can adapt to the new environment; if the curve shows a continuous upward trend, it indicates that the activated sludge cannot adapt to the new environment;

The adaptable new environment includes: the environment in which the activated sludge changes from normal dissolved oxygen to low dissolved oxygen; the environment in which the amount of chlorine added in the activated sludge is a low chlorine amount;

The new environment to which the activated sludge is not suitable includes: an environment in which the amount of chlorine added to the activated sludge is high.

Further, in the step 1), the specific process for the activated sludge to enter the endogenous respiration state is:

Take 300ml of activated sludge from the sewage treatment plant, and add tap water at a volume ratio of 1:3 to dilute the sludge. The activated sludge sample is stirred, precipitated, supernatant removed, and the volume is adjusted to 1% of the activated sludge dilution. /2 volume, then wash the activated sludge once with PBS buffer solution at 0.2ml/s for 3s, repeat the mud washing for 3 times, then add tap water to adjust the volume of the activated sludge mixture to the original volume of the activated sludge dilution , that is, 1.2L, aeration for 2h, the activated sludge enters the endogenous respiration state.

Further, in the steps 2), 3), the breath spectrum DO-t curve is obtained through the following conditional control:

Control the duration of the DO decline phase t: 5≤t≤25min and the variation range of the DO decline phase: 6.0≤DO≤4.0mg/L.

Further, in steps 2) and 3), the temperature control in the process of obtaining the DO-t curve of the respiration map is 8-45°C.

Further, in step 1), the buffer solution for cleaning the sludge is a PBS buffer solution, which is a mixed solution of the following components:

A: The concentration of KH ₂ PO ₄ is 1.5-2.5 mmol·L ^-1 ;

B: The concentration of Na ₂ HPO ₄ is 8-12 mmol·L ^-1 ;

C: NaCl concentration is 135-140 mmol·L ^-1 ;

D: KCl concentration is 2.5-3.0 mmol·L ^-1 .

Further, add the nitrogen source to the sludge in step 3) and add 3-14 mg of nitrogen element and nitrogen-containing compound per 1 g of activated sludge in a mass ratio.

Further, the nitrogen source added to the sludge in step 3) is nitrogen-containing inorganic matter or nitrogen-containing organic matter, and the nitrogen-containing inorganic matter is ammonium chloride or ammonium sulfate; the nitrogen-containing organic matter is urea.

Further, in step 3), add a carbon source to the sludge according to the mass ratio of 200-700 mg of carbon-containing organic matter per 1 g of activated sludge; the carbon source is a single carbon source: sodium acetate, glucose, or starch.

Further, the mass ratio of the nitrogen source to the carbon source is added according to the ratio of dry activated sludge.

Further, the normal dissolved oxygen DO is 2-4mg/L, and the low dissolved oxygen is DO<0.5mg/L;

The low chlorine content is NaClO≤8‰ in the activated sludge, and the high chlorine content is NaClO≥15‰ in the activated sludge.

Further, whether described activated sludge adapts to the judging method of new environment is:

Judging whether the activated sludge adapts to the new environment according to the change trend of the OURe/OURt-t curve: ①The curve shows a trend of rising first and then stabilizing or rising first and then falling, indicating that the activated sludge can adapt to the new environment; ②The curve is changed after one week of environmental conditions It is still rising, that is, showing a continuous upward trend, indicating that the endogenous respiration rate OURe is increasing, and the respiration rate of the corresponding functional flora is weakening, indicating that the activated sludge cannot adapt to the new environment, and the activity of the functional flora will continue to decline until Disappear and eventually disintegrate; ③The curve shows a downward trend, indicating that the new environment is conducive to the survival of functional flora and the growth of activated sludge.

The present invention has the following advantages:

1) The present invention finds the relationship between the change trend of the endogenous respiration rate OURe and the total respiration rate OURt ratio (OURe/OURt) over time t in the respiration map and whether the activated sludge adapts to the new environment, and the activated sludge can be accurately evaluated Whether it adapts to the new environment provides an effective judgment method for solving the indicators indicating that the activated sludge adapts to the new environment, and has certain guiding significance.

2) The method of the present invention is convenient for detection. The steps are simple and easy, and the test equipment is automated. For example, using the WBM series sewage treatment intelligent operation workstation provided by Xi'an Lvbiao Water Environment Technology Co., Ltd. can automatically test the sludge to be tested without human operation.

3) The parameters used in the present invention are not water quality, which is a non-intuitive indicator of the operation of the sewage plant, but focus on the core subject sludge of sewage treatment. The state of the sludge itself is the key that really affects the operation of the sewage plant. The change trend of the activated sludge endogenous respiration ratio (OURe/OURt) with respect to the time t provided by the present invention is used as a predictive indicator of whether the activated sludge adapts to the new environment, which is more simple and intuitive in detection.

Description of drawings

Figure 1(a)(b)(c)(d) are the (OURe/OURt)-t curves obtained under the conditions of reducing DO and adding different amounts of sodium hypochlorite to the activated sludge of a sewage plant in Xi'an respectively.

detailed description

The present invention will be further described below by means of drawings and embodiments.

The invention evaluates whether the activated sludge adapts to the new environment by analyzing the breath spectrum of the activated sludge.

The present invention assesses whether activated sludge adapts to the new environment, comprising the following steps:

1) Take 300ml of activated sludge from the sewage treatment plant, add tap water at a volume ratio of 1:3 to dilute the sludge, and stir the activated sludge sample, remove the supernatant, and dilute to the volume of the activated sludge dilution 1/2 volume, then wash the activated sludge once with PBS buffer solution at 0.2ml/s for 3s, repeat the mud washing for 3 times, then add tap water to dilute the activated sludge mixture to the original volume of the activated sludge dilution Volume, that is, 1.2L, and fully aerated for 2 hours, so that the activated sludge enters the endogenous respiration state;

The buffer solution is a mixture of the following components:

A: KH2PO4 concentration is 1.5～2.5mmol·L ^-1 ;

B: The concentration of Na2HPO4 is 8-12mmol·L ^-1 ;

C: NaCl concentration is 135-140 mmol·L ^-1 ;

D: KCl concentration is 2.5-3.0 mmol·L ^-1 .

2) After entering the state of endogenous respiration, fully stir to obtain the first section of DO-t curve, and get its slope by fitting, which is the endogenous respiration rate OURe of activated sludge;

3) After step 2), nitrogen sources are added to the sludge. Add 3-14 mg nitrogen-containing inorganic matter (ammonium chloride or ammonium sulfate) or nitrogen-containing organic matter (urea) per 1 g of activated sludge by mass ratio. Then add carbon source and add 200-700 mg of carbon-containing organic matter (sodium acetate, glucose or starch) per 1 g of activated sludge according to the mass ratio. Fully aerate until the dissolved oxygen DO reaches 7mg/L or more, and then fully stir, and finally get another DO-t curve of the respiration map, and get its slope by fitting, which is the total respiration rate OURt;

The DO-t curve of the breath spectrum satisfies the conditions: control the duration of the DO decline phase t: 5≤t≤25min and the change range of the DO decline phase: 6.0≤DO≤4.0mg/L. The temperature control in the process of obtaining the DO-t curve of respiration atlas was 8-45°C.

The mass ratio of nitrogen source and carbon source is added according to the proportion of dry activated sludge.

4) Repeat steps 1) to 3) to obtain the time-varying endogenous respiration rate OURe and the total sludge respiration rate OURt respectively.

5) Use the OURe/OURt ratio to draw a curve about time t, and evaluate whether the activated sludge adapts to the new environment according to the changing trend of the OURe/OURt-t curve: ①The curve rises first and then stabilizes or first rises and then declines, indicating the activity Sludge can adapt to the new environment; ②The curve is still rising after changing the environmental conditions for a week, that is, showing a continuous upward trend, indicating that the endogenous respiration rate OURe is increasing, and the respiration rate of the corresponding functional flora is weakening, indicating that the activated sludge Unable to adapt to the new environment, the activity of functional flora will continue to decline until it disappears, and finally disintegrates; ③The curve shows a downward trend, indicating that the new environment is conducive to the survival of functional flora and the growth of activated sludge.

Among them, the functional flora includes autotrophic bacteria and heterotrophic bacteria.

Total respiration rate OURt = endogenous respiration rate OURe + respiration rate of autotrophic bacteria mainly removing ammonia nitrogen + respiration rate of heterotrophic bacteria removing BOD ₅ .

Activated sludge can be adapted to new environments including:

① Activated sludge is in an environment where normal dissolved oxygen changes to low dissolved oxygen; the normal dissolved oxygen DO is 2-4mg/L, and the low dissolved oxygen is DO<0.5mg/L; ② The amount of chlorine added to the activated sludge is ≤8 ‰environment of.

The activated sludge cannot adapt to the new environment including: the environment where the amount of chlorine added to the activated sludge is NaClO ≥ 15‰.

The effect of the present invention is further illustrated below through specific examples.

1) Sampling of A ² /O process activated sludge from a sewage treatment plant in Xi'an;

2) Select the WBM450 series intelligent operation workstation provided by Xi'an Lvbiao Water Environment Technology Co., Ltd. as the equipment for obtaining the DO-t curve of the activated sludge respiration map;

3) Take 300ml of activated sludge from the sewage treatment plant and dilute it with tap water at a ratio of 1:3 by volume. The activated sludge sample is stirred, precipitated, supernatant removed, and the volume is adjusted to 1/2 of the activated sludge dilution Volume, wash the mud with PBS buffer solution for 3 times, then add tap water to adjust the volume of the activated sludge mixture to the original volume of the activated sludge dilution, that is, 1.2L, fully aerate for 2 hours, and the activated sludge enters the endogenous respiration state;

4) After the sludge enters the endogenous respiration in step 3), fully stir for 30 minutes to obtain the DO-t curve of the respiration map, take the interval section of 6-4mg/l dissolved oxygen, and obtain the slope by fitting, that is, the endogenous respiration rate OURe;

Table 1 has provided the example of process parameter situation of different embodiments in this experiment.

Table 1 different embodiment raw material process parameters

5) After step 4), add a nitrogen source so that the ammonia nitrogen concentration is 50 mg/l, add a carbon source so that the COD concentration in the container is 300 mg/l, and then fully aerate until the dissolved oxygen DO reaches a level above 7 mg/L, Afterwards, fully stir for 30 minutes, and obtain another section of DO-t curve of respiration spectrum at high temperature, take the section of dissolved oxygen of 6-4mg/l, and get its slope by fitting, then the total sludge after adding nitrogen and carbon will be obtained. respiration rate OURt;

6) On the basis of reducing DO (<0.5mg/l) and adding different amounts of sodium hypochlorite (2‰, 8‰, 15‰), the above steps were repeated to continuously monitor the sludge, and the changes over time under the respective conditions were obtained. The endogenous respiration rate OURe value and the total sludge respiration rate OUR value are used to draw a curve about time t with the ratio of OURe/OURt.

Example analysis:

Take the A ² /O process activated sludge from a sewage treatment plant in Xi'an City, by reducing DO (the normal DO is 2-4mg/L), and adding different amounts of sodium hypochlorite, and measure the respiratory spectrum DO-t under the respective conditions curve. From the DO-t curve of the obtained respiration spectrum, the OURe/OURt curve under various environmental conditions is obtained, as shown in Figure 1. Figure 1(a) shows that the reactor operates under normal dissolved oxygen for a period of time, then turns to a low dissolved oxygen (<0.5mg/L) environment, changes its environment after a period of time, restores it to normal dissolved oxygen and adds 15 ‰ NaClO, the curve change diagram of activated sludge OURe/OURt-t; and Figure 1(b) is after restarting the experiment, the activated sludge survived under normal dissolved oxygen for a period of time, and then turned to low dissolved oxygen (<0.5mg /L) of OURe/OURt-t curve changes for survival; Figure 1(c)(d) shows two experiments at the same time, and the rectangular broken line in the figure indicates the process of adding NaClO, which was added after adding 2‰ 8‰ and then stop adding NaClO activated sludge OURe/OURt-t curve diagram. It was found that after adding different amounts of sodium hypochlorite, the sludge disintegrated under high chlorine content (15mg/g SS), that is, the sludge could not adapt to the new environment; while under low chlorine content (2‰, 8‰), the sludge did not It will disintegrate, that is, the sludge can adapt to the new environment. In the experiment of reducing DO, the sludge did not disintegrate, that is, the sludge can adapt to the new environment. Comparing the OURe/OURt-t curves under their respective conditions, it is obvious: ①The curves show a trend of rising first and then stabilizing or first rising and then falling under the environment conditions of low dissolved oxygen or low chlorine content. After adding 2‰, add 8 Chlorination was stopped after ‰NaClO, and the curve also showed a trend of rising first and then falling, indicating that the activated sludge can adapt to the new environment, and the short-term rise is due to the adaptive adjustment of microorganisms; The continuous upward trend indicates that the activated sludge cannot adapt to the new environment, and the activity of the functional flora continues to decline until it disappears and finally disintegrates. ③The curve shows a direct downward trend, indicating that the new environment is conducive to the survival of functional flora and the growth of activated sludge. This is consistent with the activated sludge situation reflected by the changing trend of the OURe/OURt-t curve obtained from the experiment. That is to say, the DO-t curve of the respiration spectrum is obtained by taking the activated sludge from the sewage treatment plant, and the OURe/OURt-t curve is obtained according to it. Through the change trend of this curve, it is possible to accurately evaluate whether the activated sludge can adapt to the new environment.

In summary, the present invention is a method for assessing whether activated sludge adapts to a new environment based on respiration patterns.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, and the DO amount and chlorine dosage are adjusted to control the duration of the DO-t curve DO decline stage. t, the variation range of the DO descending stage, thereby obtaining the DO-t curve of the respiratory spectrum, and then obtaining the process of the OURe/OURt-t curve, only a preferred embodiment has been given here, and in addition, the rights of the present invention also include other Changes in environmental factors such as temperature, pH, etc. Any changes or substitutions that can be easily conceived by any person skilled in the art within the technical scope disclosed in the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. a kind of method whether being shaked down based on breathing collection of illustrative plates assessment activated sludge is it is characterised in that the method includes Following steps:

1) take sludge sewage, with buffer solution, activated sludge is cleaned multiple times, and abundant aeration, make work Property mud enter endogenous respiration state；

2) after activated sludge enters endogenous respiration state, it is sufficiently stirred for, obtains first paragraph breathing collection of illustrative plates do-t curve, matching obtains To its slope, as activated sludge endogenous respiration rate oure；

3) in step 2) it is separately added into nitrogen source and carbon source in activated sludge, then fully aeration reaches more than 7mg/l to dissolved oxygen do, fills Divide stirring, obtain another section of breathing collection of illustrative plates do-t curve, matching obtains its slope, as total breathing rate ourt；

4) repeat step 1) -3), respectively obtain time dependent endogenous respiration rate oure value and the total breathing rate of mud Ourt value；

5) use the drafting of oure/ourt ratio with regard to the curve of time t, according to the variation tendency of oure/ourt-t curve, assessment is lived Property mud whether shake down, if curve be in first rise after steadily or downward trend after first rising, indication activated sludge is permissible Shake down；If curve is in continue ascendant trend, indication activated sludge cannot shake down；

The adaptable new environment of described activated sludge includes: activated sludge switchs to the environment of low dissolved oxygen from normal dissolved oxygen, or activity In mud, chlorine dosage is the environment of low chlorine dose；

The unconformable new environment of described activated sludge includes: in activated sludge, chlorine dosage is the environment of high chlorine dose.

2. according to a kind of method whether being shaked down based on breathing collection of illustrative plates assessment activated sludge described in claim 1, its It is characterised by, described step 1) in, activated sludge enters endogenous respiration state detailed process and is:

Take the activated sludge 300ml of sewage treatment plant, and add tap water with the ratio of volume ratio 1:3 and mud is diluted, will Activated sludge sample passes through 1/2 volume stir, precipitate, removing supernatant, being settled to activated sludge diluent, is then delayed with pbs Rush solution with 0.2ml/s, enter 3s detergent active mud once, so repeat to wash mud 3 times, add tap water afterwards by activated sludge Mixed liquor is settled to the original volume of activated sludge diluent, i.e. 1.2l, aeration 2h, and activated sludge enters endogenous respiration state.

3. according to a kind of method whether being shaked down based on breathing collection of illustrative plates assessment activated sludge described in claim 1, its Be characterised by, described step 2), 3) in, breathing the following condition of collection of illustrative plates do-t curve negotiating control obtain:

Control do persistent period decline stage t:5≤t≤25min and do decline stage excursion: 6.0≤do≤4.0mg/l.

4. according to a kind of method whether being shaked down based on breathing collection of illustrative plates assessment activated sludge described in claim 1, its Be characterised by, step 2), 3) in obtain breathing collection of illustrative plates do-t curve procedures temperature control be 8～45 DEG C.

5. according to a kind of method whether being shaked down based on breathing collection of illustrative plates assessment activated sludge described in claim 1, its It is characterised by, step 1) in, the buffer solution of described cleaning mud is pbs buffer solution, and this buffer solution mixes for following components Conjunction liquid:

A:kh₂po₄Concentration is 1.5～2.5mmol l^-1；

B:na₂hpo₄Concentration is 8～12mmol l^-1；

C:nacl concentration is 135～140mmol l^-1；

D:kcl concentration is 2.5～3.0mmol l^-1.

6. according to a kind of method whether being shaked down based on breathing collection of illustrative plates assessment activated sludge described in claim 1, its Be characterised by, step 3) described in mud added in the every in mass ratio 1g activated sludge of nitrogen source add 3～14mg nitrogen matter Amount nitrogen-containing compound；Described is Nitrogen element inorganic matters or Nitrogen element Organic substance to mud addition nitrogen source, described Nitrogen element Inorganic matters are ammonium chloride or ammonium sulfate；Described Nitrogen element Organic substance is carbamide.

7. according to a kind of method whether being shaked down based on breathing collection of illustrative plates assessment activated sludge described in claim 1, its Be characterised by, step 3) described in mud added in the every in mass ratio 1g activated sludge of carbon source add 200～700mg carbon containing unit Plain Organic substance；Described carbon elements Organic substance is single carbon source: sodium acetate, glucose or starch.

8. according to a kind of method whether being shaked down based on breathing collection of illustrative plates assessment activated sludge described in claim 1, its It is characterised by, activated sludge is added with nitrogen source and the mass ratio of carbon source adds according to dried activated sludge ratio.

9. according to a kind of method whether being shaked down based on breathing collection of illustrative plates assessment activated sludge described in claim 1, its It is characterised by, described normal dissolved oxygen do is 2-4mg/l, described low dissolved oxygen is do ＜ 0.5mg/l；

Described low chlorine dose is naclo≤8 ‰ in activated sludge, and high chlorine dose is naclo >=15 ‰ in activated sludge.

10. according to a kind of method whether being shaked down based on breathing collection of illustrative plates assessment activated sludge described in claim 1, its It is characterised by, the decision method whether described activated sludge shakes down is:

Judge whether activated sludge shakes down according to the variation tendency of oure/ourt-t curve: after 1. curve is in first rising Downward trend after rising steadily or first, indication activated sludge is adapted to new environment；2. curve is after environmental condition changes one week Still rising, that is, be in continue ascendant trend, illustrating that endogenous respiration rate oure is increasing, the breathing speed of corresponding feature flora Weakening, indication activated sludge cannot shake down rate, the activity of feature flora by continuous decrease until disappearing, last solution Body；3. curve is on a declining curve, and indication new environment is conducive to the existence of feature flora, is conducive to the growth of activated sludge.