JPH02169096A - Activated-sludge abnormality preventive agent and method for preventing abnormality and bulking of activated sludge - Google Patents

Abstract

PURPOSE:To prevent the abnormality of activated sludge and to sterilize bulk forming fungi by using a water-soluble polymer obtained by the reaction of an alkylenepolyamine and/or a polyalkylenepolyamine and an epihalohydrin. CONSTITUTION:Activated sludge is bulked by at least one kind of filamentous fungus selected from a group consisting of type 021N, etc., and/or Microthrix parvicella. To the activated sludge bulked or to be bulked by the fungi or the waste contg. the activated sludge, 0.05-25 pts.wt, based on 100 pts.wt. of the dry solid component of the activated sludge, of a water-soluble polymer obtained by the reaction of an alkylenepolyamine and/or a polyalkylenepolyamine and an epihalohydrin is added. By this method, the bulking of activated sludge due to the fungi is specifically prevented. In addition, the water-soluble polymer is added to activated sludge or to the waste water contg. the activated sludge. As a result, the foaming or scumming of the activat ed sludge in an aeration tank and the treated water after settling due to ray fungi is specifically prevented.

Description

[Detailed Description of the Invention] [Background of the Invention] Technical Field The present invention relates to abnormal phenomena in activated sludge, such as the formation of a foam layer on the top of an aeration tank or settling tank during aeration treatment of activated sludge,
scum or cause bulking (swelling phenomenon),
The present invention also relates to an abnormal phenomenon prevention agent that prevents treated water from foaming or scum formation after activated sludge sedimentation, and an abnormal phenomenon prevention method using the agent. The present invention also provides an abnormal phenomenon prevention agent that effectively prevents abnormal phenomena in activated sludge, such as bulking of activated sludge, caused by specific filamentous fungi or actinomycetes in a method for preventing abnormal phenomena in activated sludge by adding chemicals. , and a method for preventing abnormal phenomena in activated sludge using the same. The present invention also relates to a method for effectively preventing abnormal phenomena in activated sludge caused by specific actiobacteria.

Activated sludge method is one of the biological methods used for wastewater treatment. This method utilizes the properties of activated sludge, a sludge produced by blowing air into wastewater containing organic matter and propagating microorganisms.
Activated sludge produces highly absorbent flocs whose specific gravity is higher than that of water (for example, it is said to be around 1.003), which settles when left to stand, leaving clear treated water. This takes advantage of the phenomenon of "remaining". The settled activated sludge is reused as return sludge.

Sewage, sewage and various organic industrial wastewaters are usually treated by activated sludge method. During treatment using this method, changes in the flow rate of inflowing wastewater, changes in organic matter in inflowing wastewater, and changes in the types of microorganisms such as mold and filamentous bacteria that have grown in the sewer pipes occur. It is known that the microbial flora in activated sludge changes in response to these changes. For example, when the free solid content in the influent raw water is low (or when the sludge retention time (SRT) is large), Nocardia aIIarae proliferates in large quantities in the activated sludge, producing surface-active mycolic acid, which causes the formation of air bubbles. This promotes stabilization and causes sludge-colored bubbles to accumulate at the top of the aeration tank and final settling tank before being discharged.The discharged water itself may foam and spoil its appearance.This rapid change in the microbial flora In such cases (for example, when filamentous bacteria increase), the sludge swells, sedimentation becomes poor, the sludge rises to near the water surface, the amount of sludge overflow increases, the treatment capacity decreases, and in some cases, treatment becomes impossible. A so-called bulking phenomenon occurs.

When this phenomenon occurs, the sludge becomes whitish and has air bubbles attached.
It is very light and difficult to settle, and a foam layer with sludge attached sometimes accumulates at the top of the aeration tank, reaching several tens of centimeters or more. Sludge attached to the air bubbles accumulated in the upper part of the aeration tank and sludge in the air bubbles collected from the aeration tank may rot and emit a bad odor, and sludge in the air bubbles accumulated in the aeration tank may be transferred to treated water from the final settling tank. If the treated water is discharged along with the treated water, the treated water may have a poor appearance due to foaming, BOD and COD may rise, and the removal rate may be extremely reduced, causing environmental pollution.

As an indicator of whether activated sludge is functioning normally, SVI (Sludge Volua+e
Index, tQ mud index] value. This SvI value is expressed as the volume occupied by Ig activated sludge during 30 minutes of settling. SVI of activated sludge that exhibits normal functions
The value is 50 to 150, especially 100 or less, but that of activated sludge that has undergone bulking can be as high as 300 to 800. However, the increase in SVI value caused by actinomycetes is about 200 to 300, and as a result, sewage outflow due to the rise of the sludge interface may be observed in winter.

In activated sludge that has generated such foaming, scum, or bulking, it is not the 8-crystal that restores its function;
In the worst case scenario, the sludge will need to be replaced, and in the case of replacement, factories will have to stop using it until the sludge has acclimated, which will have a serious impact on the factory's production plan.

Furthermore, even in public sewage treatment plants, the outflow of expanded sludge and a decrease in sludge concentration may reduce BOD removal efficiency, leading to environmental pollution, which may become a major social problem.

Prior art methods for preventing bulking of activated sludge are disclosed in Japanese Patent Publications No. 58-14274 and Japanese Patent Publication No. 58-1.427.
A method described in Publication No. 5 and the like has been proposed.

The method described in Japanese Patent Publication No. 58-14274 is a method in which one or more dithiocarbamates having a specific structure are dissolved in water and added to activated sludge. However, this method only considers cases where the cause of bulking is abnormal proliferation of filamentous fungi, and is not effective when there are other causes. Furthermore, when using this method, even if the degree of damage to the activated sludge is relatively minor, it takes more than 4 days, and in some cases more than 10 days, for the effect to appear, and moreover, it takes a large amount of water every day. The disadvantage is that it must be added continuously.

The method described in Japanese Patent Publication No. 58-14275 contains valine, leucine, isoleucine, glutamic acid,
A composition containing one or more amino acids such as phenylalanine and tyrosine as an active ingredient is added to activated sludge. When using this method, it is necessary to continuously add a composition containing these active ingredients to the inflowing wastewater at a level as large as 0.5 to 3 kg1rd for 3 hours or more to achieve the effect. The drawback is that it takes more than 24 hours.

The bulking phenomenon of activated sludge is caused by 5phaerot i
lus (Sphaerochilus spp.), Thjothrix
(Thiotrix sp.), Aspergillus
(Aspergillus spp.), Penicllum
In addition to abnormal growth of filamentous bacteria and fungi such as Penicillium (genus Penicillium), a highly viscous jelly-like substance is generated in activated sludge depending on the season or nutritional status, which makes it difficult for the sludge to settle. It may also show bulking phenomenon.

In the latter case, Z n CI 2 or
It is said that it is effective to add a cationic polyacrylamide polymer flocculant. However, according to the experiments conducted by the present inventor, this method has been found to be effective because activated sludge tends to contain air bubbles in a III tank, etc., and activated sludge containing air bubbles has an extremely reduced ability to treat wastewater and causes bulking. It was found that there was no significant effect on prevention.

In addition, to prevent foaming, scum, and bulking caused by actiobacteria, a method is known in which an antifoaming agent, such as a carboxylic acid ester compound, is mixed with shower water and sprayed in the aeration tank and final settling tank. It is being According to the inventor's experiments, this method of mixing and spraying antifoaming agent does not suppress foaming, but only destroys the formed bubble layer.
It turned out that it had little effect.

Furthermore, without relying on the addition of chemicals, for example, anaerobic and aerobic treatment,
Attempts have been made to restore the normal microbial flora using only operating conditions such as adding a large amount of suspended solids (SS) without using an initial settling tank, but type 021N and type 17
No satisfactory solution has yet been proposed for bulking due to overgrowth of at least one of type 01, type 1702 and type 0041 filamentous bacteria.

In general final treatment plants that treat urban sewage, bulking is most often caused by filamentous bacteria, and conventionally bulking has been caused by filamentous bacteria, such as Sphaerochilus (natans) and Begiatoa (Beg.
glatoa) are said to be representative of the causative microorganisms (Journal of the Sewage Works Association, Vol. 22, No. 252, No. 2-
12 pages (1978)).

By the way, with the recent development of sewerage systems, rainwater and domestic wastewater have come to be treated separately. As a result, it is presumed that when municipal sewage, which is domestic wastewater, is treated by the activated sludge method, changes occur in the filamentous bacteria that cause bulking.

[Summary of the invention]

Summary The present invention aims to specifically prevent specific activated sludge abnormalities and specifically kill bulking-forming filamentous bacteria in response to recent changes in urban sewage. This object is attempted to be achieved by using a polymer as an abnormal W prevention agent or a bulking prevention agent.

That is, the activated sludge abnormal phenomenon prevention agent according to the present invention is
It is characterized in that it consists of a water-soluble polymer obtained by reacting an alkylene polyamine and/or a polyalkylene polyamine with epihalohydrin.

Methods for preventing bulking of activated sludge include type 021N, type 1701, type 1702 type 0041 and/or Microthrix barbizella () Ilcrot.
To activated 19 sludge or wastewater containing the same in which bulking is to occur or has occurred due to at least one type of filamentous bacteria selected from the group consisting of P. hrl. .05 to 25 parts by weight of alkylene polyamine and/or polyalkylene polyamine and shrimp 1
It is characterized by adding a water-soluble polymer obtained by reaction with 10-hydrin.

In addition, the method for preventing abnormal reduction of activated sludge according to the present invention is to add 0.05 to 25% of the activated sludge or waste water containing it to 100 parts by weight of dry solids of the activated sludge in the treatment of wastewater by the activated sludge method. parts by weight of alkylene polyamine and/or polyalkylene polyamine and shrimp 1
10 A method characterized by adding a water-soluble polymer obtained by reaction with hydrin to liberate actinomycetes from activated sludge that should cause foaming, scum or bulking in treated water after sedimentation of activated sludge. It is.

Effects According to the present invention, the above objects are achieved and type 02
1N, type 1701, type 1702 type 0041
or bulking of activated sludge caused by Microthrix barbicella filamentous bacteria is specifically prevented.

That is, according to the water-soluble polymer according to the present invention, if the water-soluble polymer is added at the time when signs of an increase in the SVI value due to abnormal growth of filamentous bacteria are observed, or after the SVI value has increased. , the SVI value can be quickly maintained at or below the original level without substantial further increase in the SVI value. Moreover, the drug of the present invention has a long duration of effect after one addition.

Therefore, implementing the present invention will be extremely beneficial in terms of activated sludge process management.

In addition, according to another abnormal phenomenon prevention method according to the present invention, the above object is achieved, and the foaming or scum formation and bulking phenomenon of activated sludge aeration tank sludge and treated water after sedimentation caused by actinomycetes are identified. is prevented.

That is, according to the water-soluble polymer according to the present invention, when a foaming phenomenon appears in the aeration tank and signs that the foam starts to accumulate as scum are observed, or when a bulking phenomenon is observed, the water-soluble polymer is removed. The addition of can quickly maintain the SVI value at or below the original level without substantial further expansion of the foam layer. Moreover, the drug of the present invention has a long duration of effect after one addition.

Therefore, implementing the present invention will be extremely beneficial in terms of activated sludge process management.

In addition to these effects, the present invention also has the following effects.

(1) When using the method of the present invention, simply adding a water-soluble polymer to the activated sludge treatment system can suppress the increase in SVI of activated sludge in a short time.

(2) When the method of the present invention is used, the activated sludge in one aeration unit does not expand, the sedimentation volume can be reduced, the activated sludge concentration can be kept high, and the BOD removal effect can be significantly increased.

(3) According to the present invention and another invention, the sedimentation and separation of activated sludge becomes extremely easy even in a sedimentation tank.

The water-soluble polymer used in the present invention is known per se, and the method of using it as a sedimentation accelerator is known.
It seems unexpected that this polymer can destroy actinomycetes and thereby prevent abnormal phenomena and bulking of activated sludge.

[Detailed description of the invention]

As mentioned above, the present invention relates to prevention of abnormal phenomena in activated sludge, which prevents specific abnormalities in activated sludge and hulking of activated sludge caused by specific filamentous bacteria.

Target activated sludge The activated sludge targeted by the present invention and another invention is one that causes foaming or scum formation in treated water after sedimentation by actinomycetes, and type 021N and type 1701.
, type 1702, type 0041 and Mlcrothrix parvl
The bulking is caused by at least one type of filamentous bacteria such as C. cella.

Actinomycetes that exist in activated sludge and have such negative effects include Nocardia amarae.
amarae), Rhodocox 10 Dokurus (R
hodococcus rhodochrous), and others.

If it is necessary to isolate such actinomycetes, they can be easily obtained from the foam tank, scum, and sludge accumulated in the upper layer of the aeration tank of activated sludge from sewage.

Filamentous bacterial rods of type 021N and type 0041, H, EIkclbooi: Prog, Watcr T
cch,, vol. 8.

No. 6, pp. 153-161 (1977).

Filamentous bacteria of types 1701 and 1702 are P, P
, SLrom and Ri, Jenklns:Journa
l WPCF.

Volume 56, No. 5, pp. 449-459 (1984)
It is defined in .

As mentioned above, urban sewage activated sludge containing these filamentous bacteria has recently become more common, and if it is necessary to isolate these microorganisms, they can be easily obtained from these sewage activated sludges. .

Water-Soluble Cationic Polymers The agents used in the present invention are water-soluble polymers whose chemical entity is obtained by the reaction of alkylene polyamines and/or polyalkylene polyamines with epihalohydrin.

Suitable alkylene polyamines and polyalkylene polyamines for producing such polymers are those represented by the general formula, and as epihalohydrins, those represented by the general formula are suitable.

Specific examples of such alkylene polyamines (n-1) include ethylenediamine, N,N-dimethylethylenediamine, N,N'-dimethylethylenediamine,
N,N-diethylethylenediamine, propylenediamine, N,N-dimethylpropylenediamine, N,N,N
' , N'-tej·ramethylethylenediamine, etc., and specific examples of the polyalkylene polyamines (n-2 to 5) include diethylenetriamine, triethylenetriamine, tetraethylenepentamine, and the like. These polyamines are within the above groups and 1! ? Can be used in combination between.

In epihalohydrin, the halogens are fluorine, chlorine,
Bromine or iodine compounds are generally targeted, but epichlorohydrin is preferred at least for economic reasons.

In order to react the polyamine and epihalohydrin as described above, 0.0.
5 to 1.75 mol, and using a closed reaction vessel with a stirrer, the internal temperature of the reaction vessel was adjusted to 30 to 1.75 mol in an inert gas atmosphere.
A temperature range of 10°C is preferred.

More specifically, the polyamine is treated with a stirrer, a reflux condenser,
Pour into a closed reaction container equipped with a thermometer, etc., replace the atmosphere inside the container with nitrogen gas, and add epihalohydrin continuously or batchwise while stirring and controlling the temperature inside the reaction container so that it does not rise too much. It is better to do so.

The water-soluble polymer thus obtained is further processed,
It is possible to replace the halogen (derived from epihalohydrin) as a counterion with another anion, or to remove the counterion to convert the water-soluble polymer into a hydroxide.

The molecular weight of the water-soluble polymer obtained as described above can be determined based on the intrinsic viscosity [η], which is measured and calculated at 25° C. after dissolving in a 2 mol/liter KBr aqueous solution. In the present invention, [η] is 0. 01. dl/
g or more, preferably 0.02 dl/g or more, 0.5
dl/g or less, more preferably 0. It is desirable to use one with a value of 3 dl/r or less. If [η] is too small, for example less than 0.01 dl/g, the adsorption to activated sludge will decrease and the sustainability of the bulking prevention effect will decrease, which is not preferable.

Moreover, when [η] is larger than 0.5 dl/g, activated sludge envelops filamentous bacteria and forms large flocs, -
The sedimentation properties of the sludge only improve temporarily, but bulking due to filamentous bacteria tends to occur again after a few days.

The water-soluble polymer thus obtained can also be made into a solid by removing the solvent (usually water). However, it is preferable and usual to use the aqueous solution produced as an aqueous solution as it is or after diluting or concentrating as necessary to prevent bulking of activated sludge.

Abnormal phenomenon of activated sludge / Prevention of bulking Abnormal phenomenon / Except for the target activated sludge to be prevented from bulking as described above and the changes in treatment conditions that should occur as a result, the chemical addition according to the present invention Prevention of bulking of activated sludge is essentially the same as conventional methods.

Specifically, the water-soluble polymer is added to an appropriate concentration, for example, 0.1
An aqueous solution having a concentration of about 10% by weight may be prepared, and this aqueous solution may be added according to any of the following methods or a combination of these two or more methods.

(1) Method of mixing with inflowing wastewater and sending it to an aeration tank.

(2) A method of directly adding it to (6) where bulking of activated sludge is occurring in the aeration tank or settling tank.

(3) Method of adding to returned sludge.

If the amount of this water-soluble polymer used is too small,
This is not preferable because the object of the invention will not be achieved, and conversely, if it is too large, it will be washed out of the system along with wastewater, which is not preferable. If the target activated sludge contains specific filamentous bacteria, if too much J-soluble polymer is used, the filamentous bacteria will be rapidly destroyed and the treated water will suddenly become cloudy, or it will be mixed with the wastewater. In some cases, the C of the treated water may be washed out of the system.
This is not preferable because it may cause an increase in OD. The amount of J4 to be used is preferably selected in the range of 0.05 to 25 parts by weight based on 100 parts by weight of dry solid content of activated sludge. More preferably, it is in the range of 0.1 to 10 Tfl parts.

When the water-soluble polymer is added to the activated sludge within the above range, no increase in SVI and no sludge outflow due to foaming or scum generation will be observed for one month or more. When signs of accumulation of a foam layer containing sludge in the upper part of the aeration tank are observed, it is advisable to add the water-soluble polymer in the above range at that point.

When a water-soluble polymer is added once within the above range to activated sludge, no increase in the SVI value is observed for one month or more. Thereafter, when signs of an increase in the SVI value are observed, the water-soluble cationic polymer is preferably added within the above range. It has been observed that the rapid increase in filamentous bacteria is controlled for about one month after the addition of this water-soluble polymer.

Experimental example Example A-1 Monthly average: 3,500 go/day, BOD: 220 ■/L.

At a public sewage treatment plant that processes separated urban sewage wastewater with a suspended solid content (S At the top of the aeration tank, a foam layer that had turned brown and had trapped about 10 to 20 c+n of sludge remained forever. This foam layer overflows from the top of the aeration tank and pollutes the surrounding area, or the overflowing material rots and becomes a source of bad odors.To make matters worse, the foam layer containing sludge flows into the final settling tank. The BOD and COD values of the effluent that flowed out together with the treated water were 2, respectively.
Exceeded 0Il1g/L. Furthermore, the dry sludge concentration (MLSS) of the returned sludge from this treatment plant was 4500 mg/L, and the MLSS in the aeration tank was 2100 mg/L.

When the sludge in the aeration tank and sedimentation tank at this treatment plant was stained with Durham and observed using a phase contrast microscope, many typical actinomycetes were observed in the width and surrounding area of the sludge, along with the floc formation layer. Ta. The sludge contains actinomycetes, and the sludge attracts the mycolic acid secreted by actinomycetes and their filamentous forms, reducing the density of the sludge and making it difficult to settle.

The sludge from the public sewage treatment plant mentioned above was put into a small model of activated sludge treatment with an aeration tank capacity of 3L and a settling tank capacity IL, which simulates an actual public sewage treatment plant, and the amount of dissolved oxygen in the aeration tank is reduced to 1.
．． -2 mg/L 1. : Adjust the inflow raw water of the above public sewage treatment plants so that the BOD load is 0.4 kg/kg M
Continuously add sea urchin on a schedule at about LSS/day, and
Continuous operation was performed with a sludge return rate of 50%.

In this small model of activated sludge treatment, the molar ratio of epichlorohydrin and N,N-dimethylethylenediamine was 1:1.
A mixed reaction composition obtained by adding epichlorohydrin to N,N-dimethylethylenediamine while maintaining the reaction temperature at 90°C until the ratio of 0.5 g of any composition whose intrinsic viscosity [η] is 0.10 dl is
It was continuously added to the return sludge line for 50 hours while being diluted with tap water to 0 times.

Eight hours after the start of continuous addition, the brown foam layer that had remained at the top of the aeration tank gradually decreased. 12
After time has passed, sedimentation Ff! Many actinomycetes were observed in the treated water from I, and the actinomycetes present in aeration (6) were detached from the sludge, increasing the number of flocs.

The SVI value decreased to 150, and the position of the sludge interface in the settling tank also decreased. After 50:181, the SVI value is 110.
Became. It was confirmed that actinomycetes were extremely reduced in the sludge where the aeration tank existed at this time. In addition, the activated sludge formed firmer flocs than before it was added. As a result, after 100 hours, the brown foam layer that had accumulated at the top of the aeration tank almost disappeared, and the sedimentation properties were significantly improved, the SVI value reached 100, and the return sludge concentration decreased accordingly. The MLSS value has increased to 5700■/L, and the sludge concentration in the aeration tank has also decreased to 2500tag/L.
Since the temperature has increased to L, good quality treated water can now be obtained. Furthermore, the sludge interface in the settling tank rose, and sludge no longer flowed out.

The actinomycetes are destroyed and flow out with the treated water, but the suspended solids concentration at this time is 5 mg/L terminal disease, and the BOD
and COD values are each less than 20 mg/L,
It was good as treated water.

Example A-2 The activated sludge containing actinomycetes of Example A-1 was processed using a small-sized activated sludge treatment system with an aeration capacity of 5 L and a sedimentation tank capacity of 1.7 L, assuming an actual public sewage treatment plant. It was placed in a model and operated continuously under the same conditions as the dissolved oxygen amount, inflow raw water addition amount, and sludge return rate of the aeration tank described in Example 1.

In this small model of activated sludge treatment, shrimp chlorohydrin was added to N,N-dimethylpropylene diamine until the molar ratio of epichlorohydrin and NN-dimethylpropylene diamine was 1:1, and the reaction temperature was raised to 80°C. Mixed reaction composition (2) obtained by adding, stirring and mixing while maintaining
Intrinsic viscosity [η
] is 0.14 dl/sr) 1. ．． 1sr, 1
The sludge was continuously added to the return sludge line for 60 hours while being diluted with tap water.

After 10 hours had passed since the start of continuous addition, the brown foam layer that had remained in the upper part of the aeration tank gradually decreased.

After 15 hours had passed, many actinomycetes were observed in the treated water from the settling tank, and the actinomycetes in the aeration tank were detached from the sludge, increasing the density of flocs. The S■■ value decreased to 150, and the position of the sludge interface in the settling tank also decreased. After 50 hours, the SVI value reached 100. It was confirmed that actinomycetes were extremely reduced in the sludge present in the aeration tank at this time.

In addition, the activated sludge formed firmer flocs than before it was added. As a result, after 150 hours,
The brown foam layer that had accumulated at the top of the aeration tank has almost disappeared, and the sedimentation properties have been significantly improved, and 5VIri has decreased to 9.
0, and as a result, the return sludge concentration increases to MLSS value 6.
000 g/L, and the sludge concentration in the aeration tank also reached MLSS.
Since the value has increased to 2,600 g/L, good treated water can now be obtained. Furthermore, the sludge interface in the settling tank rose, and sludge no longer flowed out.

The actinomycetes are destroyed and flow out together with the treated water, but the suspended solids concentration at this time is less than 511 g/L, and the BO
The D and COD values were each less than 2011 g/L, which was good for treated water.

For about one month after the addition of the water-soluble polymer, the rapid increase in actinomycetes was suppressed, even though the inflow raw water was thought to contain actinomycetes.

Example A-3 The activated sludge containing actinomycetes of Example A-1 was
Example A
Continuous operation was performed under the same conditions as the amount of dissolved oxygen in the aeration tank, the amount of added raw water added, and the sludge return rate described in -1.

In this small model of activated sludge treatment, epichlorohydrin was added to tritylene triamine while maintaining the reaction temperature at 70°C, and the mixture was stirred until the molar ratio of epichlorohydrin and triethylene triamine was 1:1.4. The mixed reaction composition (2 mol/liter of KBr
0.6 g of a composition having an intrinsic viscosity [η] of 0.15 dl/g as measured in an aqueous solution was continuously added to the return sludge line for 50 hours while being diluted 100 times with tap water.

After 10 hours from the start of continuous addition, the brown foam layer that had accumulated at the top of the aeration tank decreased by about 3096, and many actinomycetes were observed in the treated water due to the sedimentation.
The actinomycetes in the aeration tank were detached from the sludge, and the density of the flocs increased.

The SVI value decreased to 170, and the position of the sludge interface in the settling tank also decreased. After 50 hours, 5VIliI! became 130. It was confirmed that actinomycetes were extremely reduced in the sludge present in the aeration tank at this time. In addition, the activated sludge formed firmer flocs than before it was added. As a result, after 150 hours, the brown foam layer that had accumulated at the top of the aeration tank almost disappeared, and the sedimentation properties were significantly improved, and the SvI value reached 100. MLSS value 5400mg
/L, and the sludge concentration in the aeration tank also rose to 2300mg/L, making it possible to obtain good treated water. Furthermore, the sludge interface in the settling tank rose, and sludge no longer flowed out.

The actinomycetes are destroyed and flow out together with the treated water, but at this time the Il, I# solid content concentration is less than 5 mg/L,
The BOD and COD values were each less than 2011/L, which was good for treated water.

Example A-4 The activated sludge containing actinomycetes of Example A-1 was
The activated sludge treatment was carried out in a small (small) mold similar to that in Example A-1, and was continuously operated under the same conditions as the amount of dissolved oxygen in the aeration tank, the amount of added raw water added, and the activated sludge return rate described in Example A-1. .

In this small model of activated sludge treatment, N was mixed with epichlorohydrin in a molar ratio of 1:0.3.

N-dimethylethylenediamine-triethylenetriamine mixture until the molar ratio is 1:0.8.
, epichlorohydrin was added to the N-dimethylethylenediamine-triethylenetriamine mixture at a reaction temperature of 70°C.
0.6 g of the mixed reaction composition obtained by adding and stirring and mixing while maintaining the temperature at It was continuously added to the return mud line for 50 hours while being diluted with tap water.

After 10 hours from the start of continuous addition, the brown foam layer that had accumulated at the top of the aeration tank decreased by about 30%, and many actinomycetes were observed in the treated water from the settling tank, as well as in the aeration tank. The actinomycetes were detached from the sludge, and the density of the flocs increased.

The SVI value decreased to 160, and the position of the sludge interface in the settling tank also decreased. After 50 hours, the SVI value became 130. It was confirmed that actinomycetes were extremely reduced in the sludge present in the aeration tank at this time. In addition, the activated sludge formed firmer flocs than before it was added.

As a result, after 150 hours, the brown foam layer that had accumulated at the top of the aeration tank had almost disappeared, and the sedimentation properties had been significantly improved, and the SVI value reached 100. The MLSS value increased to 5500 rag/L, and the sludge concentration in the aeration tank also decreased to 2400 rAg/L.
Since the temperature has increased to L, good quality treated water can now be obtained. Furthermore, the sludge interface in the settling tank rises, preventing sludge from flowing out.

The actinomycetes are destroyed and flow out with the treated water, but the suspended solids concentration at this time is less than 5 mg/L, and the BOD
and COD values are each less than 20 mg/L,
It was good as treated water.

Example A-5 The activated sludge of Example A-1 in which Streptococcus bacteria were present was placed in a small model p for activated sludge treatment similar to Example A-1, and the activated sludge as described in Example A-1 was Continuous operation was performed under the same conditions as the amount of dissolved oxygen in the aeration tank, the amount of added raw water inflow, and the activated sludge return rate.

In this small model of activated sludge treatment, epichlorohydrin and N, N, N', N'-tetramethylethylenediamine were also mixed with N until the molar ratio was 1.1.
A mixed reaction composition (2
0.8 g of a composition with an ultimate [η] of 0.018 dl/g as measured by a mol/liter KBr aqueous solution was continuously added to the return sludge line for 50 hours while being diluted 100 times with tap water.

24 hours after the start of continuous addition, the foam layer that had accumulated at the top of the aeration tank decreased by about 20%, and many actinomycetes were observed in the treated water from the settling tank, as well as actinomycetes in the aeration tank. Bacteria have separated from the sludge.

After 50 hours had passed, the SVI value reached 180, and the foam layer remaining in the upper part of the aeration tank decreased by more than 50'.

However, 6 days after the start of continuous addition, actinomycetes increased again, and the foam layer remaining at the top of the aeration tank increased.
After 10 liters from the start of continuous addition, the foamed layer returned to the state before continuous addition.

Example A-6 The activated sludge containing actinomycetes of Example A-1 was
Example A
Continuous operation was carried out under the same conditions as the amount of dissolved oxygen in the aeration tank, the amount of added raw water added, and the activated sludge return rate described in -1.

In this small model of activated sludge treatment, the molar ratio of N and N to epichlorohydrin was adjusted to 1:1.

-N, N- until the molar ratio of the dimethylethylenediamine-triethylenetriamine mixture is 1=1.
Mixed reaction composition obtained by adding epichlorohydrin to a dimethylethylenediamine-triethylenetriamine mixture while maintaining the reaction temperature at 60°C and stirring and mixing (limit [η) determined by apj with 2 mol/liter KBr aqueous solution] is 0.654 dl/g)], , Og,
50 to the return sludge line while diluting 100 times with tap water.
It was added continuously for hours.

After 24 hours had passed from the start of continuous addition, the foam layer that had remained at the top of the aeration table had decreased by about 40%.

After 50 hours, the SVI value reached 140, and the foam layer remaining in the upper part of the aeration tank was reduced by more than 60%.

However, one week after the start of continuous addition, the foam layer remaining at the top of the aeration tank increased and
After a week, the foamed layer returned to its state before continuous addition.

Comparative Example A-1 In Example A-1, with the same activated sludge and operating conditions,
The antifoam agent was added from the top of the aeration tank without adding the reaction composition of the invention. The antifoaming agent is a special paraffin ester compound (Daito Pharmaceutical Co., Ltd.'s [Minecon CJ)] mixed with water.
．． It was diluted to 1% by weight and added at a rate of 5 ml/min from the top of the aeration tank for 3 days. Although an antifoaming effect was observed where the antifoaming agent was applied, a large amount of the antifoaming agent was required to obtain a sufficient effect.

However, with the use of antifoaming agents, it has been fundamentally impossible to release actinomycetes in sludge from activated sludge.

Example B-1 Monthly average of 3000'rrlZ days, BOD is 200ff1g
/L.

At a public sewage treatment plant that processes separated urban sewerage wastewater with a suspended solids content (S MLSS) became less than 2,000 mg/L, and the MLSS in the aeration tank also became less than 1,000 mg/L, and the separation of treated water and sludge in the final settling tank deteriorated significantly. When the sludge in the aeration tank and sedimentation tank at this treatment plant was subjected to Durham staining and observed using a phase contrast microscope, it was found that in the sludge, there were type 021N and type 021N bacteria between the flocs, rather than floc-forming bacteria. 004], a larger volume of filamentous bacteria was observed.

The sludge from the above public sewage treatment plant is put into a small 1:i mold for activated sludge treatment with an aeration tank capacity of 3L and a settling tank capacity of IL, assuming an actual public sewage treatment plant, and dissolved oxygen in the aeration tank. The amount is adjusted to 1-2 mg/L, and the inflow raw water of the above public sewage treatment plant is BOD negative 61 or 1), 4 kg/kg.
The sludge was continuously added at a rate of about MLSS/day, and the sludge return rate was set to 5006, and the operation was continued.

In this small model of activated sludge treatment, the molar ratio of epichlorohydrin and N,N-dimethylethylenediamine was 1:1.
Add shrimp chlorhydrone to N,N-dimethylethylenediamine until the ratio is 0.5%.
0.5 g of the mixed reaction composition (composition with an intrinsic viscosity [η] measured with a 2 mol/liter KBr aqueous solution or 0.10 dl/f) obtained by adding and stirring while holding the
(48) to the return sludge line while diluting with tap water to 0 times.
It was added continuously for hours.

After 12 hours had passed since the start of continuous addition, many destroyed type 021N and type 0041 filamentous bacteria were observed in the treated water from the settling tank, and type 021N and type 0041 bacteria in the aeration tank were observed. As it began to be destroyed, the SVI value decreased to 200, and the interfacial sludge position in the settling tank decreased. After 48 hours, SV
The I value became 100. At this time, it was confirmed that the number of filamentous bacteria in the sludge in the aeration tank had decreased significantly. In addition, the activated sludge formed firmer flocs than before addition.

After 100 hours, the sedimentation properties were significantly improved and the SV
Since the I value became 80, the MLSS value of the returned sludge increased to 7000a+g/L, and the MLSS value of the sludge in the aeration tank increased by 10 degrees to MLSS[2600ag/L. From the above results, it is considered that the inflow raw water treatment ability of this activated sludge is significantly improved compared to that of the activated sludge before addition.

Type 021N and type 0041 filamentous bacteria are destroyed and flow out, but the suspended solids concentration at this time is 5 m
The BOD and COD values of the treated water were each 20 mg/L, and the treated water was in good condition.

Despite the fact that type 021N and type 0041 were thought to be contained in the influent raw water, the rapid increase of these filamentous bacteria was suppressed for about two months after the addition of the water-soluble polymer.

Example B-2 Monthly average is 7000TIl/day, BOD is i50my/L.

At a public sewage treatment plant that processes partially combined urban sewerage wastewater with suspended solids (SS) of 100 mg/L, the settled sludge volume index (SVI) of the aeration tank exceeds 400, and the dried sludge of the returned sludge The concentration (MLSS) became less than 20,001 gg/L, and the MLSS of the aeration tank also became less than 1,000 mg/L, and the separation of treated water and sludge in the final settling tank deteriorated significantly. When the sludge in the aeration tank and sedimentation tank of this treatment plant was Duram-stained and observed with a phase contrast microscope, it was found that typical types 1701 and 170 were found in and around the sludge.
Many filamentous bacteria of type 2 were observed.

The above activated sludge was placed in a small model of activated sludge treatment similar to that in Example B-1, and the amount of dissolved oxygen in the aeration tank, the amount of raw water added, and the sludge return rate were the same as in Example B-1. It was operated continuously under the following conditions.

In this small model of activated sludge treatment, the molar ratio of epichlorohydrin and N,N-dimethylpropylenediamine is 1:1.
A mixed reaction composition (
i? with 2 mol/liter KBr aqueous solution? 1) 0.6 g of a composition with a constant intrinsic viscosity [η] of 0.14 dl/r, 1
The sludge was continuously added to the return sludge line for 40 hours while being diluted with tap water.

After 10 hours had passed from the start of continuous addition, many types of type 1701 and type 1702 filamentous bacteria, which were thought to have been destroyed, were observed in the treated water from the settling tank, as well as type 1701 and type 702 in the aeration tank. began to be destroyed, the SVI value decreased to 220, and the interfacial sludge position in the settling tank decreased. After 40 hours, the SV
The I value became 130. At this time, it was confirmed that the number of filamentous bacteria in the sludge in the aeration tank was extremely reduced. After 70 hours, the filamentous forms of type 1701 and type 1702 filamentous bacteria were confirmed. destroyed, and
The destroyed filamentous bacteria flow out together with the treated water, and the activated sludge present in the aeration tank and settling tank is mostly type 1.
It was confirmed that no filamentous bacteria of types 701 and 1702 remained.

In addition, the activated sludge formed firmer flocs than before addition. As a result, the sedimentation property of activated sludge was significantly improved, the SVI value became 80, the return sludge concentration increased to the MLSS value of 6100II+g/L, and the sludge concentration in the aeration tank also increased to the MLSS value of 2400mg/L. It has been rising.

Type 1701 and type 1702 filamentous bacteria are destroyed and flow out, but the suspended solids concentration at this time is 5 m
g/L, and the BOD and COD values of the effluent water were each 20 my/L, which was in good condition as treated water.

For about one month after the addition of the water-soluble polymer, the rapid increase of these filamentous bacteria was suppressed, even though it is thought that type 1701 and type 1702 were present in the influent raw water.

Example B-3 The activated tri mud containing Type 021N and Type 0041 of Example B-1 was placed in a small model of activated sludge treatment similar to Example B-1, and the aeration described in Example B-1 was carried out. Continuous operation was performed under the same conditions as the amount of dissolved oxygen in the tank, the amount of added raw water inflow, and the activated sludge return rate.

In this small model of activated sludge treatment, epichlorohydrin was added to triethylenetriamine while maintaining the reaction temperature at 70°C until the molar ratio of epichlorohydrin and triethylenetriamine was 11.4, and the mixture was stirred. mixed reaction composition (2 mol/liter of KQr
Intrinsic viscosity [η] determined by 3-1 in aqueous solution is 0.15 dl/
0.8 g of the composition) was continuously added to the return sludge line for 48 hours while being diluted 100 times with tap water.

Thirteen hours after the start of continuous addition, many destroyed type 021N and type 0041 filamentous bacteria were observed in the treated water from the settling tank, and type 021N and type 0041 bacteria in the aeration tank were observed. As it began to be destroyed, the SVI value decreased to 250, and the interfacial sludge position in the settling tank began to decrease. After 48 hours, SV
The I value became 140. It was confirmed that the filamentous bacteria in the sludge present in the aeration tank at this time was extremely reduced.After 100 hours, the filamentous bacteria of type 021N and type 0041 were destroyed. The destroyed filamentous bacteria flowed out together with the treated water, and it was confirmed that almost no type 021N or type 0041 filamentous bacteria remained in the activated sludge present in the aeration tank and settling tank. .

Example B-4 The activated sludge containing Type 17υl and Type 1702 of Example B-2 was placed in a small model of activated sludge treatment similar to Example B-1, and the aeration tank described in Example B-1 was placed. Continuous operation was performed under the same conditions as the amount of dissolved oxygen, the amount of added raw water inflow, and the activated sludge return rate.

In this small model of activated sludge treatment, N was mixed with epichlorohydrin in a molar ratio of 1:0.3.

The molar ratio with the N-dimethylethylenediamine-triethylenetriamine mixture is 1. : Until the ratio is 0.8,
Epichlorohydrin was added to the N,N-dimethylethylenediamine triethylenetriamine mixture at a reaction temperature of 80°C.
A mixed reaction composition obtained by adding and stirring and mixing while maintaining the temperature at 0.0 °C (composition with an intrinsic viscosity [η] of 0.15 dl/g determined by A111 with a 2 mol/liter KBr aqueous solution)0.
Dilute 6g 100 times with tap water before returning it.
It was continuously added to the dt line for 40 hours.

After 12 hours had passed since the start of continuous addition, a large number of what were thought to be destroyed type 701 and type 1702 filamentous bacteria were observed in the treated water from the settling tank, and the bacteria 1701 and 1702 in the aeration tank were observed. and type 1702
began to be destroyed, the SVI value decreased to 240, and the interfacial sludge position in the settling tank decreased. After 70 hours, S
VI value became 150. It was confirmed that the number of filamentous bacteria in the sludge present in the aeration tank at this time was extremely reduced. After 80 hours, the filamentous forms of type 1701 and type 1702 filamentous bacteria were destroyed, and the destroyed filamentous network (1 was flowed out together with the treated water).
It was confirmed that almost no type 1701 and type 1702 filamentous bacteria remained in the activated sludge present in the aeration tank and settling tank.

Example B-5 Type 021N and Type 0041 of Example B-1
Activated TL mud existing in M% was put into a small model of activated sludge treatment similar to JB-1, and the added amount of dissolved oxygen m1 inflow raw water and activated sludge return rate of the aeration tank described in Examples B to 1 were calculated. It was operated continuously under the same conditions.

In this small model of activated sludge treatment, N, N, N,
',N'-Tetramethylethylenediamine was added with epichlorohydrin while maintaining the reaction temperature at 100°C, and mixed with stirring. Viscosity [η]
0.6 g of the composition (with a composition of 0.018 dl/g) was continuously added to the return sludge line for 48 hours while being diluted 100 times with tap water.

24 hours after the start of continuous addition, what was thought to be the destruction of type 021N and type 0041 filamentous bacteria was observed in the treated water from the settling tank, and type 021N and type 0041 in the aeration tank were destroyed. For the first time, the SVI value decreased to 350. After 48 hours, the SVI value reached 240. It was confirmed that filamentous bacteria in the sludge present in the aeration tank at this time had decreased. After 120 hours, the settling properties of the sludge were improved and the SVI value reached 200.

However, one week after the start of continuous addition, type 0
21N and type 0041 increases to 4 in SVI value.
00, and the sludge settling property in the settling tank deteriorated.

Example B-6 Activated sludge containing Type 1701 and Type 1702 of Example B-2 was placed in a small model of activated sludge treatment similar to Example B-1, and the aeration tank described in Example B-1 was placed. Continuous operation was performed under the same conditions as the amount of dissolved sigma oxygen, the amount of added raw water inflow, and the activated sludge return rate.

In this small model of activated sludge treatment, N,N-dimethyl A mixed reaction composition obtained by adding epichlorohydrin into an ethylenediamine-triethylenetriamine mixture while maintaining the reaction temperature at 60°C and stirring and mixing (intrinsic viscosity determined by Δ-1 with a 2 mol/kuteol aqueous KBr solution) [η] is 0.6
0.8 g of the 54 dl/g composition was continuously added to the return sludge line for 48 hours while being diluted 100 times with tap water.

24 hours after the start of continuous addition, type 1701
The sludge entrained Type 1702 to form large flocs, the SVI chain decreased to 230, and the interfacial sludge position in the settling tank decreased.

After 48 hours, the SVI value decreased to 150.

However, one week after the start of continuous addition, type 1
701 and type 1702 cause SVI value to be 350
sludge settling in the settling tank deteriorated.

Comparative Example B-1 In Example B-1, with the same activated sludge and operating conditions,
Without adding the reaction composition of the present invention, a sodium hypochlorite aqueous solution ((-T effective chlorine concentration 5%) was added to the return sludge line.
When it was added at a rate of 0.8 g/day for 8 days, the filamentous bacteria present in the sludge began to decrease, but the SVI value was 350, which was still not sufficient. Therefore, when sodium hypochlorite was further added at a rate of 0.8 f/day, the SVI value decreased to 180, but the treated water became extremely cloudy and the suspended solids concentration exceeded 15 mg/L. The BOD of the treated water was 20 mg/L, but the COD value exceeded 30 mg/L. When we observed the state of activated sludge under a microscope, we found that the flocs were destroyed and became very fine.
Protozoa are completely gone.

The cloudiness was due to not only the filamentous bacteria being destroyed and flowing out, but also the useful floc-forming bacteria being destroyed and flowing out. This cloudy state not only occurred while adding an aqueous solution of sodium hypochlorite (effective chlorine concentration: 5%) to the return sludge line, but also continued for three days after the addition was completed. It was observed that floc-forming bacteria were flowing out. As a result, the treated water remained cloudy, and it could hardly be said to be in good condition.

After stopping the addition of thorium hypochlorite solution (white chlorine 1 degree 596) to the return sludge line, as soon as the treated water is no longer cloudy, the refill type 021N
, the bactericidal power of type 0041 was lost, and the filamentous bacteria that had been incorporated into the sludge began to rapidly increase again, and S V E (fi reached 400) after 20 days.

Even in public sewage treatment plants that actually treat urban sewage wastewater, an aqueous solution of sodium hypochlorite (available chlorine concentration 5%) is highly toxic, so sufficient equipment and caution are required when adding it. Furthermore, since it also promotes corrosion of equipment, there are restrictions on where it can be added.

Comparative Example B-2 In Example B-1, with the same activated sludge and operating conditions,
Without adding the reaction composition of the present invention, cationic polyacrylamide (C402 manufactured by Diafloc Co., Ltd.) was added to the return sludge line at a ratio of 5%/L to the sludge in the aeration tank, and 3% was added to the return tLi mud line. When continuously added for days, the SVI value reached 150 in a state containing type 021N and type 0041.

However, after stopping the addition, it gradually started to settle...! ! i
4 days later, the SVI value reached 400.

When this sludge was observed under a microscope, it was confirmed that many filamentous bacteria of type 021N and type 0041 were present in the periphery of the sludge. When this addition was repeated, the sludge entrained air bubbles and floated to the surface in the aeration tank and settling tank, resulting in poor conditions.

Claims (1)

[Claims] 1. Type 021N, Type 1701, Type 1702
, type 0041 and Microthrix parvicella, and alkylene polyamines for preventing the bulking phenomenon of activated sludge caused by at least one kind of filamentous bacteria or the abnormal phenomenon of activated sludge caused by actinomycetes. (or) An agent for preventing abnormal phenomena in activated sludge, comprising a water-soluble polymer obtained by the reaction of polyalkylene polyamine and epihalohydrin. 2. Type 021N, Type 1701, Type 1702
, type 0041, and Microthrix parvicella, and the activated sludge or wastewater containing the same is subjected to bulking by at least one type of filamentous bacteria selected from the group consisting of Microthrix parvicella. 10
Prevention of bulking of activated sludge, characterized by adding 0.05 to 25 parts by weight to 0 parts by weight of a water-soluble polymer obtained by reacting an alkylene polyamine and/or a polyalkylene polyamine with epihalohydrin. Law. 3. In wastewater treatment by activated sludge method, activated sludge or wastewater containing it has a dry solid content of 10
By adding 0.05 to 25 parts by weight of a water-soluble polymer obtained by reacting an alkylene polyamine and/or a polyalkylene polyamine with epihalohydrin to 0 parts by weight, the treated water after activated sludge sedimentation can be A method for preventing abnormal phenomena in activated sludge, which is characterized by liberating actinomycetes that cause foaming, scum, or bulking from activated sludge.