JPH0416298A - Agent and method for preventing abnormal phenomenon of activated sludge - Google Patents

Abstract

PURPOSE:To specifically sterilize specific filamentous bacteria or actinomycetes by using a nitrogen-containing water-soluble polymer or an alkylene imine polymer or a polymer mixture of them along with a compound such as ammonia or amine. CONSTITUTION:A nitrogen-containing water-soluble polymer obtained by reacting, e.g. epihalohydrin or alkylene dihalide with amine, or an alkyleneimine polymer represented by (-R7-NH-)n (wherein R is an alkylene group), or a mixture of both polymers is set to A, and a compound such as ammonia, amine or cholohexidine hydrochloride is set to B. 0.001-50 pts.wt. of the compound B is mixed with 100 pts.wt. of the compound A on a dry solid basis and this mixture is added to 100 pts.wt. of activated sludge in an amount of 0.05-25 pts.wt. on a dry solid basis as an inhibitor. By this method, the bulking of activated sludge due to filamentous bacteria and the abnormal phenomenon of a activated sludge due to actinomycetes are selectively prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention deals with the swelling phenomenon of activated sludge, that is, bulking.
The present invention relates to an abnormal phenomenon prevention agent and method for preventing abnormal phenomena such as the formation of a foam layer and scum formation in the upper part of an aeration tank or settling tank that occur during aeration treatment of activated sludge.

[Conventional technology]

Activated sludge method is one of the biological methods used for wastewater treatment. This method blows air into wastewater containing organic matter, causing microorganisms to propagate, resulting in slurry,
In other words, it takes advantage of the properties of activated sludge, and takes advantage of the fact that activated sludge produces highly adsorbent flocs, whose specific gravity is greater than that of water (for example, it is said to be around 1.003). This allows the flocs to settle and clear treated water to be obtained. The settled activated sludge is reused as return sludge.

Sewage, human waste and various organic industrial wastewaters are usually treated with activated sludge. During treatment with this method, fluctuations in the flow rate of influent wastewater, fluctuations in organic matter in influent wastewater,
Furthermore, the types of microorganisms such as various molds, filamentous bacteria, and actinomycetes that grow in the sewer pipes change, and the microbial flora in the activated sludge changes in accordance with these changes.

For example, when the solid content in the influent raw water is low and the sludge retention time (SRT) is large, Nocardia and Amarae (Nocardi4 amara11!) proliferate in large quantities in the activated sludge, producing surface-active mycolic acid, which causes the formation of air bubbles. Stabilization is promoted, and air bubbles containing sludge accumulate in the upper part of the aeration tank or final settling tank and are discharged, and the discharged water itself may foam, damaging its appearance.

In addition, when filamentous bacteria and actinomycetes increase, the sludge swells and settles poorly, causing the sludge to rise close to the water surface, increasing the amount of sludge overflow, reducing treatment capacity, and in some cases making it impossible to treat. A so-called bulking phenomenon occurs. When this phenomenon occurs, the sludge becomes whitish, very light, and difficult to settle, and it also attracts air bubbles to the top of the aeration tank.
Sometimes the foam layer with sludge attached reaches several tens of centimeters or more and accumulates. Moreover, the sludge attached to the air bubbles accumulated at the top of the aeration tank or the sludge attached to the air bubbles overflowing from the aeration tank rots and gives off a bad odor, and the sludge in the air bubbles accumulated in the aeration tank is disposed of from the final settling tank. If it is discharged with water, it may cause poor appearance due to foaming of the treated water, and increase in BOD and COD, causing environmental sludge.

5VI (Sludge Volume Index) is one indicator of whether activated sludge is functioning normally.
, sludge volume index), and the volume occupied by 1 g of activated sludge after the activated sludge suspension is allowed to stand for 30 minutes is ml.
(JIS B 9944). The SVI value of activated sludge that functions normally is 50 to 150.
, especially less than 100, but that of activated sludge that has undergone bulking can be as high as 300 to 800. Furthermore, the increase in SVI value caused by actinomycetes is about 200 to 300, and this may cause sewage outflow due to the rise of the sludge interface.

It is not easy to restore the function of activated sludge that has generated foaming, scum, or bulking, and in the worst case, it becomes necessary to replace the sludge. It would be necessary to stop using the product until the product has become accustomed to the product, which would have a serious impact on the factory's production plan.

Even in public sewage treatment plants, BOO removal efficiency decreases due to the outflow of expanded sludge and a decrease in sludge concentration, which can lead to environmental pollution and become a major social problem.

Methods for preventing bulking of activated sludge are disclosed in Japanese Patent Publication No. 5g-14274 and Japanese Patent Publication No. 58-14275.
The method described in the above publication has been proposed.

First, the former method 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 is only applicable when the cause of bulking is abnormal growth of filamentous fungi, and is not effective when there are other causes. or,
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 a large amount must be added every day. It has the disadvantage that it cannot be used.

Next, in the latter method, a composition containing one or more of amino acids such as valine, leucine, isoleucine, glutamic acid, phenylalanine, and tyrosine as an active ingredient is added to the activated sludge in the wastewater. . When using this method, the composition containing these active ingredients is added to the influent wastewater at a rate of 0.5 Kg/m' to 5 Kg/m3.
It has the disadvantage that it needs to be continuously added at a large amount for 3 hours or more, and it takes 24 hours or more for it to be effective.

The bulking phenomenon of activated sludge is caused by 5 phaerotilu
s (Sphaerotilus spp.), Th1othrix (
Thiotrix fi4), Aspergillus
(Aspergillus spp.), Penicillium
In addition to preventing abnormal growth of filamentous bacteria and fungi such as (Penicillium spp.), a highly viscous jelly-like substance is generated in activated sludge depending on the season and nutritional status, which makes it difficult for the sludge to settle. , may also exhibit bulking phenomenon. In the latter case, it is said to be effective to add Zn[''Ia or a cationic acrylamide polymer flocculant to the wastewater. However, according to the inventor's experiments, this method It was found that activated sludge tends to contain air bubbles in an aeration tank, etc., and activated sludge containing air bubbles has an extremely reduced ability to treat wastewater, and is not significantly effective in preventing bulking.

In addition, the normal microbial flora can be restored to normal microbiota without relying on the addition of chemicals or, for example, without using anaerobic or aerobic treatment or an initial settling tank, using only operating conditions such as mixing a large amount of suspended solids (SS). Although attempts have been made, no satisfactory results have been obtained, and in particular, no satisfactory solution has been proposed for eliminating or preventing bulking caused by sheathed filamentous bacteria.

In addition, to prevent foaming, scum, and bulking caused by actinomycetes, 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. ing. According to experiments conducted by the present inventor, it has been found that this method of mixing and spraying antifoaming agent does not suppress foaming, but only destroys the bubble tank that is generated, and has almost no effect.

At general final treatment plants for municipal sewage, bulking occurs most often due to filamentous bacteria, and conventionally, bulking caused by filamentous bacteria such as Sphaerochilus and Beggiatoa
is said to be a representative of the causative microorganism. C. Sewage Association Ruins, Vol. 22, No. 252, pp. 2-12 (1985)
Year)). By the way, as a result of the recent development of sewage systems, rainwater and domestic wastewater, etc., have come to be treated separately, and as a result, bulking occurs when urban sewage, which is domestic wastewater, is treated using the activated sludge method. It is presumed that changes have also occurred in filamentous bacteria.

[Problem to be solved by the invention]

In response to recent changes in urban sewage, the present invention is designed to treat specific filamentous bacteria that cause abnormal phenomena such as bulking, especially filamentous bacteria that have sheaths, or the upper part of an aeration tank or settling tank during aeration treatment of activated sludge. The purpose is to specifically kill actinomycetes that form foam layers, scum, and cause bulking. The object of the present invention is to provide an agent for preventing abnormal phenomena and a method for preventing the same.

[Means to solve the problem]

The activated sludge abnormality prevention agent of the present invention is a nitrogen-containing water-soluble polymer obtained by reacting an amine with at least one compound selected from the group of epihalohydrin, alkylene dihalide, dieboxide, and dihalogenoalkyl ether. Contains as a component a polymer, an alkyleneimine polymer, or a mixed polymer of the polymer, and at least one or more compounds selected from the group of ammonia, amine, chlorhexidine hydrochloride, chlorhexidine gluconate, penzalconylam chloride, and benzethonium chloride. It is characterized by:

Further, in the activated sludge abnormal phenomenon prevention method of the present invention, the activated sludge abnormal phenomenon prevention agent is added to activated sludge or activated sludge-containing wastewater in an amount of 0.00% per 100 parts by weight of dry solid content of activated sludge.
It is characterized by adding 05 parts by weight to 25 parts by weight.

(2) Target activated sludge The activated sludge targeted by the anti-bulking agent of the present invention is one in which bulking or the like occurs due to filamentous bacteria or actinomycetes.

Among these filamentous bacteria are Sphaerochilus.

Natans, type 021N, type 0041, type 1
701, type 1702, Microthrix, Parvicella, etc., Sphaerochilus, natans, type 021
N.

Filamentous bacteria of type 0041 and Microthrix, Barbicella were identified by D. H. Bikelboom: Prog.
11aterTech.

8, Vol. 6, pp. 153-161 (1977). In addition, type 1701 and type 1702 filamentous bacteria are P, F, Storm, and Jenkins: Journal IIPc.
F, Vol. 56, No. 5, pp. 449-459 (1984
It is defined in 2013). In particular, Sfuesters, Natans, Tights 0041. Type 1701 and type 1702 are defined as filamentous bacteria with sheaths.

The abnormal phenomenon prevention agent of the present invention is applied to wastewater that has signs of bulking caused by these filamentous bacteria or contains activated sludge that has undergone bulking.

Further, the abnormal phenomenon prevention agent of the present invention is intended for activated sludge that causes foaming, scum, or bulking in treated water after sedimentation by 1 ml of discharge. Actinomycetes in activated sludge include Nocardia and Amarae (No.
cardla amarae), Rhodococus rhodochro (Rhodococus rhodochro)
us) etc.

(2) Activated Sludge Abnormal Phenomenon Preventing Agent The polymer in the activated sludge abnormal phenomenon preventing agent of the present invention (3) By reacting at least one compound selected from the group of epihalohydrin, alkylene dihalide, geboxide, and dihalogenoalkyl ether with an amine. The resulting nitrogen-containing water-soluble polymer, alkylene imine polymer,
Or a mixed polymer of these polymers.

In addition, in a water-soluble cationic polymer obtained by reacting at least one selected from epihalohydrin, alkylene dihalide, diepoxide, and dihalogenoalkyl ether with a secondary amine, counterions (epihalohydrin, alkylene dihalide, It includes range halides, halogens derived from dihalogenoalkyl ethers) replaced with other anions, and corresponding hydroxides.

The amine, which is a nitrogen-containing water-soluble polymer raw material, has the general formula % (R, , R, , R5 and R4 are hydrogen or carbon number 1
~3 linear or branched alkyl group, A is a straight chain or branched alkylene group having 1 to 6 carbon atoms, n is 0 to
(an integer of 5); specific examples include ammonia, methylamine, dimethylamine, diethylamine, dipropylamine, methylethylamine, monoalkylamine (n = 0);
Examples include methylpropylamine, ethylpropylamine, etc., and alkylene polyamines (n = 1) include ethylenediamine, N,N-dimethylethylenediamine, N
, N'-dimethylethylenediamine, N,N-diethylethylene, diamine, propylenediamine, N,N-dimethylpropylenediamine, N,N,N',N'-tetramethylethylenediamine, and polyalkylene polyamine (n =2 to 5) include diethylenetriamine, triethylenetriamine, tetraethylenepentamine, and the like. These amines can be used in combination within and between the above groups.

Epihalohydrins generally include those represented by U (X is halogen), and epihalohydrins in which the halogen is fluorine, chlorine, bromine, or iodine, but epichlorohydrin is preferred for economic reasons.

In addition, as the alkylene dihalide, the general formula (B is 1
~20 linear or branched alkylene groups, X is halogen), specifically dichloroethane, dichloropropane, dichlorobutane, dichlorohexane, dibromoethane, bromochloropropane, cyfuromopropane, dibromohexane , dichlorononane, etc. In particular, 1,2-dichloroethane (ethylene dichloride) is preferred for economic reasons.

In addition, the diepoxide does not have the general formula CD, or is a straight or branched alkylene group having 1 to 4 carbon atoms, or (CH2-0-CH
,).

(X is 1 to 4), specifically, 1.3-butadiene diepoxide, 1.4-pentadiene diepoxide, 1.5-hexadiene diepoxide, 1 .6-Hebutadiene diepoxide, 1.
Examples include 7-octazidine diepoxide, ethylene glycol diglycidyl ether, triethylene diglycidyl ether, and the like.

In addition, as a dihalogenoalkyl ether, the general formula % formula % (R,, R@ is a straight or branched alkylene group having 1 to 4 carbon atoms, X is a halogen, and n is an integer of 1 to 12) Specifications Specifically, when n=1, 2,2'-dichloroethyl ether, 2,2'-dibromoethyl ether, 3,3
'-dichloropropyl ether, 2,3-dichloropropyl ether, 4,4°-dichlorobutyl ether, 4
, 4°-dibromobutyl ether, etc., and n
In the case of =2, examples include dihalogenoethyl ether, etc., which can be obtained by a dehydration reaction between an ethylene oxide polymer having a polymerization degree of up to 10 and a halogenated alkyl alcohol, and in particular, 2゜2゛-dichloroethyl ether ( (hereinafter referred to as dichloroethyl ether) is preferred at least for economic reasons.

Each component of epihalohydrin, alkylene dihalide, diepoxide, and dihalogenoalkyl ether may be used alone or in combination of two or more. Moreover, when two or more types are mixed, there is no particular limitation as long as the sum of the moles of the mixture is approximately equivalent to the amine.

In order to react the amine with at least one compound selected from the group of epihalohydrin, alkylene dihalide, diepoxide, and dihalogenoalkyl ether, at least one compound selected from the group of epihalohydrin, alkylene dihalide, diepoxide, and dihalogenoalkyl ether is reacted. The sum of the moles of the compound alone or a mixture and the mole number of the amine should be approximately equal in mole, and using a closed reaction vessel equipped with a stirrer, the internal temperature of the reaction vessel should be 30°C under an inert gas atmosphere.
It is preferable to carry out the reaction at a temperature in the range of -100°C.

More specifically, a 20% to 70% aqueous solution of amine is charged into a closed reaction container equipped with a stirrer, a reflux condenser, a thermometer, etc., the atmosphere inside the container is replaced with nitrogen gas, and the mixture is heated under stirring. It is preferable to add one or a mixture of compounds selected from the group of epihalohydrin, alkylene dihalide, diepoxide, and dihalogenoalkyl ether continuously or batchwise while adjusting the temperature inside the reaction vessel to a predetermined temperature.

Water is mainly used as the reaction solvent, but methyl alcohol, ethyl alcohol, dimethylformamide, etc. may also be used in consideration of the solubility of the raw materials and reaction products.

The water-soluble polymer can be further processed to replace the tenohalogen (from epihalohydrin, alkylene dihalide, and dihalogenoalkyl ethers) as a counterion with other anions, or to remove the counterion and form the polymer. Hydroxide may also be used.

The water-soluble polymer thus obtained can be dissolved in a 2 mol/l KBr aqueous solution and measured, and the molecular weight can be determined from the calculated intrinsic viscosity [η] at 25°C. In the present invention, [η] is 0. 5 dl/g
The following are preferred.

When [η] is larger than 0.5 dl/g, the activated sludge envelops filamentous bacteria and actinomycetes to form large flocs, and the sedimentation properties of the sludge only improve temporarily, which lasts for several days. This is undesirable because bulking and foaming scum will occur again afterwards, and if the intrinsic viscosity is extremely low, the adsorption to activated sludge will decrease, which will reduce the sustainability of the activated sludge's effect of preventing abnormal phenomena, which is undesirable.

Water-soluble polymers can be made into solids by removing the solvent (usually water), and those produced as aqueous solutions are preferably used as they are, or diluted or concentrated as necessary.

In addition, the alkylene imine polymer has the general formula % formula %) (wherein, R1 is an alkylene group, preferably having 1 to 8 carbon atoms.
is a straight chain or branched alkylene group. A plurality of R7s may be the same or different.

n indicates the degree of polymerization of the alkylene imine polymer, and is a number such that the molecular weight of the polymer is preferably 70.000 or less. ) Furthermore, these alkylene imine polymers may not have a completely linear structure as shown in the above general formula, but may have branches.

Such alkyleneimine polymers include ethyleneimine polymers, propyleneimine polymers, trimethyleneimine polymers, tetramethyleneimine polymers, hexamethyleneimine polymers, copolymers thereof, and at least two types thereof. It is a mixture of etc.

Among these, ethyleneimine polymers are particularly preferred for economic reasons. This product can be obtained by ring-opening polymerization of ethyleneimine using a cationic catalyst, but it can also be obtained by the reaction of ethylene dihalide with ethylenediamine or ammonia, the condensation reaction of ethanolamine, etc.

Next, the second component in the abnormal phenomenon preventive agent of the present invention will be explained.

Nitrogen-containing water-soluble polymers, alkylene imine polymers, or mixtures of such polymers obtained by reacting at least one compound selected from the group of epihalohydrins, alkylene dihalides, diepoxides, dihalogenoalkyl ethers with amines. The second component that constitutes the abnormal phenomenon preventive agent of the present invention together with the polymer includes, for example, ammonia,
It consists of at least one compound selected from the group of amines, chlorhexidine hydrochloride, chlorhexidine gluconate, benzalkonium chloride, and benzethonium chloride.

It is preferable to use ammonia that is generally commercially available as an aqueous solution with a predetermined concentration. Chlorhexidine hydrochloride, chlorhexidine gluconate, benzalkonium chloride, and benzethonium chloride are each expressed as C22H-0C12N.

・2HCI,C2zHsoC1zNIo・2C,H,,
Ot, [C6H3C)1. N(CI(3)2C,,)
+2. , +l] CI, and C2,)142CINO2
``10th revised Japanese Pharmacopoeia commentary ^・B-C'' (
Supervised by the Japan Official Book Association, published by Shoten last month, 1932
6), pages 0 to 419, pages C-675, pages C-343, and pages C-348. Each of these compounds is commercially available as a solution at a predetermined concentration.

In addition, the amine in the second component has the general formula % (Ra, R,, R,. and R11 are hydrogen or a straight or branched alkyl group having 1 to 3 carbon atoms, and E is a carbon Those represented by a linear or branched alkylene group of numbers 1 to 4, where n is an integer of O to 3) are suitable.

Monoalkylamines (n = 0) include methylamine, dimethylamine, diethylamine, dipropylamine, methylethylamine, methylpropylamine, ethylpropylamine, etc., and alkylene polyamines (n = 1) include ethylenediamine, N , N
-dimethylethylenediamine, N,N'-dimethylethylenediamine, N,N-diethylethylenediaminepropylenediamine, N.

N-dimethylpropylene diamine, N, N, N', N'
Examples include -tetramethylethylenediamine, and further examples of polyalkyleneamines (n=2 to 3) include diethylenetriamine, triethylenetriamine, and the like.

The mixing ratio of each component in the abnormal phenomenon preventive agent of the present invention is as follows:
One or more of the above-mentioned polymers or mixed polymers thereof and one or more of the second components are prepared in advance so that the dry solid content of the polymer is 10
0 parts by weight, the second component compound is mixed in a ratio of 0.001 parts by weight to 50 parts by weight, more preferably 0.1 parts by weight to 20 parts by weight, to prevent abnormal phenomena in activated sludge. It is recommended to use it as an agent in activated sludge.

In mixing the above-mentioned polymer or mixed polymer with the second component, especially when ammonia and amine are used for mixing, it is preferable to mix at room temperature or lower in order to avoid reaction between the two.

In addition, the above-mentioned polymer or mixed polymer is effective in preventing bulking caused by filamentous bacteria and foaming scum caused by actinomycetes even when used alone, but the amount of the second component used is relative to the dry solid content of the polymer. If it is less than 0.001 parts by weight, it will not be particularly effective in preventing bulking caused by filamentous bacteria having sheaths, and if it is more than 50 parts by weight, it will have a strong effect on activated sludge, leading to an increase in COD, etc. Undesirable.

(Method for preventing abnormal phenomena in activated sludge) The target activated sludge in which abnormal phenomena should be prevented contains the above-mentioned actinomycetes and specific filamentous bacteria. The method for preventing abnormal phenomena in activated sludge by adding chemicals is the same as the conventional method.

Specifically, a nitrogen-containing water-soluble polymer obtained by reacting an amine with at least one compound selected from the group of shrimp helohydrin, alkylene dihalide, dieboxide, and dihalogenoalkyl ether, alkylene imine polymer, Or the second component is 0.001 parts by weight to 5 parts by weight based on 100 parts by weight of dry solid content of the mixed polymer of the polymer.
0 parts by weight, particularly preferably 0.1 parts by weight to 20 parts by weight of the abnormal phenomenon preventive agent, as an aqueous solution with an appropriate concentration, for example, 0.1 parts by weight to 10 parts by weight. It may be added by one of the following methods or a combination of two or more of these methods.

■ A method of mixing with the inflowing wastewater and sending it to the aeration tank.

■ Method of adding directly to an aeration tank or settling tank where activated sludge is bulking or foaming.

■ Method of adding to returned sludge.

If the amount of this abnormal phenomenon prevention agent used is too small, the purpose of the present invention will not be achieved, and if it is too large, actinomycetes and filamentous bacteria will be rapidly destroyed, resulting in rapid cloudiness of treated water or waste water. The CO of the treated water is also flushed out of the system.
This is not preferable because it increases D. The amount used is 0.05 parts by weight to 2 parts by weight per 100 parts by weight of dry solid content of activated sludge.
It is best to choose within a range of 5 parts by weight. More preferably 0.
It ranges from 1 part by weight to 10 parts by weight.

When the abnormal phenomenon preventive agent of the present invention is added to activated sludge once within the above range, no increase in Sl value is observed for one month or more. Thereafter, if a tendency for the SVI value to increase is observed, it is advisable to add the abnormality prevention agent within the above range at that point.

[Action and effect of invention]

As described above, according to the present invention, bulking of activated sludge caused by filamentous bacteria and abnormal phenomena of activated sludge caused by actinomycetes can be selectively prevented.

In particular, sheathed filamentous bacteria (Sphaerochilus).

Natans, type 0041, type 17 inch and type 1
702 etc.) has a remarkable effect on bulking caused by

That is, according to the abnormal phenomenon preventive agent of the present invention, when the abnormal phenomenon preventive agent is added at the time when signs of an increase in the SVI value or foaming phenomenon due to abnormal proliferation of filamentous bacteria and actinomycetes are observed, the SVI is immediately reduced. The SVI value can be maintained at or below the original level without substantial further increase in value.

The abnormal phenomenon preventive agent of the present invention is a nitrogen-containing water-soluble polymer, an alkylene imine, obtained by reacting an amine with at least one compound selected from the group of epihalohydrin, alkylene dihalide, diepoxide, and dihalogenoalkyl ether. By combining both the polymer or a mixed polymer of the polymer and the second component, specific filamentous bacteria, especially sheathing filamentous bacteria and actinomycetes, can be destroyed and activated sludge caused by them can be destroyed. It has been discovered that abnormal phenomena such as bulking can be effectively prevented.

Hereinafter, the present invention will be specifically explained with reference to Examples.

Examples 1 to 2 and Comparative Examples 1 to 3 will be described in which the activated sludge contains filamentous bacteria, and Examples 3 to 4 and Comparative Example 4 in which the activated sludge contains actinomycetes.

Adjustment of abnormal phenomenon preventive agent ■, Adjustment of present invention samples A, D and E1 Comparative sample B%C The molar ratio of dimethylamine and epichlorohydrin is 1=1
Epichlorohydrin was added to a 50% dimethylamine aqueous solution while maintaining the reaction temperature at 85°C, and the mixture was stirred and mixed until a ratio of 2 mol/l was obtained.
The intrinsic viscosity [η] measured with a KBr aqueous solution is 0.11 d.
l/g composition) was diluted with water to give a purity of 50% by weight.

A 25% ammonia aqueous solution was added to this 50% mixed reaction composition, and the ammonia component was 1.5% by weight, 0.0005% by weight, and 6% by weight, respectively, based on the dry solid content of the mixed reaction composition.
The resulting samples were designated as Invention Sample A, Comparative Sample B, and Comparative Sample C, respectively, and a 50% dimethylamine aqueous solution was added to the same 50% mixed reaction composition. were added at 20° C. and stirred and mixed so that the dimethylamine component was 2.0% by weight based on the dry solid content of the composition, and the resulting sample was used as a sample of the present invention.

In addition, chlorhexidine gluconate solution (manufactured by Sumitomo Chemical ■, 5% Hibitene) and benzethrium chloride were added to the same 50% mixed reaction composition at 1.5% by weight and 0°, respectively, based on the 50% mixed reaction composition. The sample obtained by adding 1% by weight and stirring and mixing was designated as the sample E of the present invention.

(2) Preparation of sample F of the present invention A 50% aqueous solution of dimethylamine-N, N, N', N'-tetramethylethylenediamine mixture whose molar ratio was adjusted in advance at a ratio of 1 = 0.3 and =1
The molar ratio with the mixture of ethylene glycol diglycidyl ether and dichloroethyl ether adjusted to 11.
A mixed reaction composition (extremely A composition with a viscosity [η] of 0.15 dl/g) and an ethyleneimine polymer with an average molecular weight of 10°000 (Nippon Shokubai Kogyo)
(trade name: Epomin, grade 5P-200), 1:1
and diluted with water to obtain 50% purity.

To this mixed reaction composition, 10% by weight of ethylenediamine was added.
The mixture was added at 20° C. and mixed by stirring, and the obtained sample was designated as Sample F of the present invention.

(2) Preparation of comparative sample G A 50% aqueous solution of methylamine-N, N, N', N-tetramethylethylenediamine mixture whose molar ratio was adjusted in advance at a ratio of 1:0.3 was mixed with a 50% aqueous solution at a molar ratio of 1:1. Add the epichlorohydrin-propylene dichloride mixture into a 50% aqueous solution of the amine mixture and stir while maintaining the reaction temperature at 80°C until the molar ratio of the mixture of shrimp-chlorohydrin-propylene dichloride adjusted to approximately 1:1. The resulting mixed reaction composition (intrinsic viscosity [
η] is 0. 86 dl/g composition) diluted with water to
The purity was set as 0%.

A 25% ammonia aqueous solution was added to this reaction composition at 20°C so that the ammonia component was 2.0% by weight based on the dry solid content of the mixed reaction composition, and the mixture was stirred and the resulting samples were compared. It was designated as sample G.

[Example 1] Monthly average 50,000m3/day, BOO 200mg/day
At a public sewage treatment plant that processes urban sewerage wastewater using a separate system, the SVI of the aeration tank exceeded 500, and the separation of treated water and sludge in the final settling tank deteriorated significantly.

When the sludge in the aeration tank and settling tank at this treatment plant was observed using a phase contrast microscope, it was found that type 021N was present between the flocs rather than floc-forming bacteria.

The volumes of filamentous bacteria of type 0041, type 1701, and type 1702 were larger, and in particular, many filamentous bacteria having sheaths of type 0041 and type 1702 were observed.

Two lines of this public treatment plant (aeration tank capacity = 4.400 m
), 1 ton of sample A of the present invention was added to the return sludge line for 3 hours.
It was added continuously for several days.

1 day, 3 days, and 10 days after the start of continuous addition to the sample of the present invention
SVI of sludge in the aeration tank after 1 day, 20 days and 30 days
, and the COD of the treated water were measured.

The results are shown in Table 1.

[Example 2] Monthly average 5. OOO+n'/day, 80 mouthfuls 200mg/
j! At a public sewage treatment plant that processes wastewater from a separate urban sewage system, the SV of the aeration tank exceeded 550, and the separation of treated water and sludge in the final settling tank deteriorated significantly.

When the sludge in the aeration tank and settling tank of this treatment plant was observed using a phase contrast microscope, it was found that between the flocs, there were considerably more filamentous bacteria of Sphaerocilus and Natans than floc-forming bacteria. Ta.

The sludge from this public treatment plant was put into a small activated sludge treatment model with an aeration tank capacity of 3L and a sedimentation tank capacity of 11, simulating an actual treatment plant, and the dissolved oxygen in the aeration tank was adjusted to 1 mg/1 to 2 m2.
g/j! The inflow raw water from the public treatment plant mentioned above was added continuously on a daily basis to about 4 kg/kg MLSS/day with a zero load of 6 mouths, and the return sludge rate was set to 50%, and the system was operated continuously.

In the return sludge line of this small model, the present invention sample, E,
4 while diluting 1.2 g of each F 100 times with water.
The addition was continued for 8 hours.

For the sample of the present invention, the SVI of the sludge in the aeration tank and the COD of the treated water were measured in the same manner as in Example 1 from the start of continuous addition.

The results are shown in Table 1.

[Comparative Example 1] The sludge from the public treatment plant in Example 2 was placed in a small model of activated sludge similar to that in Example 2, and the model was continuously operated under the same operating conditions as in Example 2.

Into the return sludge line of this small model, 1.5 g each of comparative samples 81C and 81G was diluted 100 times with water.
The addition was continued for 8 hours.

From the start of continuous addition of each comparative sample, the svr of the sludge in the aeration tank and the COD of the treated water were measured in the same manner as in Example 1.

The results are shown in Table 1.

[Comparative Example 2] The sludge from the public treatment plant in Example 2 was placed in a small model of activated sludge similar to that in Example 2, and the model was continuously operated under the same operating conditions as in Example 2.

Add 0.8 g of sodium hypochlorite aqueous solution (available chlorine concentration 5%) to the return sludge line of this small activated sludge model.
When the filamentous bacteria contained in the sludge began to decrease after adding it at a rate of 0.8 g/day for 7 days, the SVI value was still 390, which was still not sufficient, so the addition of 0.8 g/day was continued. It was added continuously for 7 days.

SVI of sludge in the aeration tank and COD of treated water from the start of continuous addition of sodium hypochlorite as in Example 1
was measured.

The results are shown in Table 1.

[Comparative Example 3] The sludge from the public treatment plant used in Example 2 was placed in a small activated sludge model similar to that in Example 2, and continuously operated under the same operating conditions as in Example 2.

In the return sludge line of this small model of activated sludge, cationic polyacrylamide (Clifix CP627 manufactured by Kurita Kogyo ■) was used. When added continuously for 5 days at a rate of 2g/day, the SVI value was 200 when it contained filamentous bacteria.
However, after the addition was stopped, the sedimentation property worsened, and two days after the addition was finished, the SVI value was 340, so it was further reduced to 0.
．． It was added continuously for 5 days at a rate of 2 g/day.

From the start of continuous addition of cationic polyacrylamide,
As in Example 1, the SVI of the sludge in the aeration tank and the C00 of the treated water were measured.

The results are shown in Table 1.

(Left below) Table 1 and microscopic observation of the activated sludge in the aeration tank revealed the following.

■, C1 of Comparative Example 1 In Comparative Example 2, addition of comparative sample 01 sodium hypochlorite destroyed not only filamentous bacteria but also useful floc-forming bacteria, and the treated water became extremely cloudy. .

In Comparative Example 1, 01 Comparative Example 3, the SVI value of activated sludge temporarily decreased due to the addition of Comparative Sample H, cationic polyacrylamide, but when the addition was stopped, the SVI value of activated sludge increased again. In the case of cationic polyacrylamide, when the addition was repeated, the sludge entrained air bubbles and floated to the surface in the aeration tank, resulting in poor conditions.

Although the SVI value of the comparative sample of Comparative Example 1 decreased to some extent, filamentous bacteria remained in the sludge.
No significant effect was obtained.

According to the sample of the present invention, the amount of added chemicals was small compared to the comparative sample, and the SVI value decreased immediately after the addition of the chemicals, and the sedimentation properties of activated sludge were significantly improved, and furthermore, it was found that the effect lasted for a long time.

(2) When using the sample of the present invention, filamentous bacteria in the sludge present in the aeration tank and sedimentation tank are extremely reduced compared to each comparative sample, and the activated sludge forms firm flocs.

(2) When using the sample of the present invention, filamentous bacteria are destroyed and flowed out, but the COO value of the treated water is 20 mg/l or less, which is good as treated water.

[Example 3] Monthly average 14,000 m'/day, 800 200 mg/day
At a public sewage treatment plant that processes urban sewerage wastewater using a separate system, the SVI of the aeration tank is approximately 300, but there is a brown foaming scum layer containing sludge at the top of the aeration tank and final settling tank. It remained unresolved forever.

When the sludge in the aeration tank and settling tank of this treatment plant was observed using a phase contrast microscope, many typical actinomycetes attached to floc-forming bacteria were observed. Sludge adhered to mycolic acid secreted by actinomycetes and filamentous forms of actinomycetes, forming a foaming scum layer on the upper part of the aeration tank and final settling tank.

Two lines of this public treatment plant (aeration tank capacity = 4.400 m
'), 1 or 2 tons of the sample of the present invention was continuously added to the return sludge line for 3 days.

1 day, 3 days, and 10 days after the start of continuous addition of sample A of the present invention
After 1 day, 20 days, and 30 days, the amount of foamed scum at the aeration tank interface, the SVI of the sludge in the aeration tank, and the COD of the treated water were measured.

However, the amount of foamed scum at the interface of the aeration tank is the ratio of the volume of foamed scum before the start of continuous addition of sample A of the present invention, that is, the volume of foamed scum before the start of continuous addition to 100.
Expressed as a percentage.

The results are shown in Table 2.

[Example 4] The sludge from the public treatment plant in Example 3 was put into a small model of activated sludge treatment, which simulates an actual treatment plant, with an aeration tank capacity of 3 J and a sedimentation tank capacity of 11, and the dissolved oxygen in the aeration tank was 1mg/J!
~2mg/j! The inflow raw water of the public treatment plant mentioned above is continuously added on a schedule to a BOD load of 0.4 g/Kg MLSS/day, and the return sludge rate is 5.
Continuous operation was carried out at 0%.

In the return sludge line of this small model, the present invention sample D%E,
4 while diluting 1.5 g of each of F 100 times with water.
The addition was continued for 8 hours.

From the start of continuous addition of the present invention sample, as in Example 3, the amount of foamed scum at the aeration tank interface, the SVI of sludge in the aeration tank,
And the COD of the treated water was measured.

The results are shown in Table 2.

[Comparative Example 4] Activated sludge similar to Example 3 was placed in a small activated sludge model similar to Example 4, and under the same operating conditions as Example 4, an antifoaming agent was added from the top of the aeration tank.

As an antifoaming agent, a special paraffinic ester compound (Minecon C manufactured by Daito Pharmaceutical Co., Ltd.) was diluted with water to 0.1% by weight and continuously added from the top of the aeration tank at a rate of 8 cnl/min for 5 days.

Since the antifoaming effect was not sufficient, the addition was continued for 5 days at a rate of 8 ml/17 minutes.

Similar to Example 3, from the start of continuous addition of the antifoaming agent, the amount of foamed scum at the aeration tank interface, the SVI of the sludge in the aeration tank, and the COD of the treated water were measured.

The results are shown in Table 2.

(Left below) Table 2 and microscopic observation of the activated sludge in the aeration tank revealed the following.

■When using the inventive sample, compared to Comparative Example 4,
With a small amount of added chemicals, foaming scum caused by actinomycetes is immediately reduced after addition, the SVl value of the sludge is reduced, the sedimentation properties of activated sludge are significantly improved, and the effect is long-lasting.

In the case of Comparative Example 4, the foamed scum at the aeration tank interface was temporarily reduced by adding the antifoaming agent, but when the addition was stopped, the foamed scum accumulated at the aeration tank interface again.

■When using the inventive sample, compared to Comparative Example 4,
The actinomycetes in the sludge present in the aeration tank and settling tank are drastically reduced, and the activated sludge forms solid flocs.

(2) When using the sample of the present invention, the actinomycetes are destroyed and exist in the treated water and flow out, but the COO value of the treated water is 20.
mg/It or less, which is good for treated water.

Claims (4)

[Claims] (1) Nitrogen-containing water-soluble polymers, alkylene imine polymers, or alkylene imine polymers obtained by reacting at least one compound selected from the group of epihalohydrins, alkylene dihalides, diepoxides, and dihalogenoalkyl ethers with amines; An agent for preventing abnormal development of activated sludge, which contains as a component a mixed polymer of coalescence and at least one or more compounds selected from the group of ammonia, amine, chlorhexidine hydrochloride, chlorhexidine gluconate, benzalkonium chloride, and benzethonium chloride. . (2) the above epihalohydrin, alkylene dihalide,
Dry solid content of a nitrogen-containing water-soluble polymer, an alkyleneimine polymer, or a mixed polymer of said polymers obtained by reaction of at least one compound selected from the group of diepoxides and dihalogenoalkyl ethers with an amine. 1
At least one compound selected from the group consisting of ammonia, amines, chlorhexidine hydrochloride, chlorhexidine gluconate, benzalkonium chloride, and benzethonium chloride is added at a ratio of 0.001 to 50 parts by weight per 0.00 parts by weight. 2. The activated sludge abnormal development inhibitor according to claim 1, wherein the activated sludge abnormal development inhibitor is mixed. (3) the above epihalohydrin, alkylene dihalide,
A nitrogen-containing water-soluble polymer obtained by reacting an amine with at least one compound selected from the group of diepoxides, dihalogenoalkyl ethers, at a concentration of 2 mol/l
The activated sludge abnormal phenomenon preventive agent according to claim 1, which has an intrinsic viscosity [η] of 0.5 dl/g or less at 25° C., which is calculated by dissolving it in a KBr aqueous solution. (4) At least one member selected from the group of epihalohydrin, alkylene dihalide, diepoxide, and dihalogenoalkyl ether is added to activated sludge or activated sludge-containing wastewater.
a nitrogen-containing water-soluble polymer, an alkyleneimine polymer, or a mixed polymer of said polymer obtained by the reaction of a compound with an amine, and ammonia, an amine, chlorhexidine hydrochloride, chlorhexidine gluconate, benzalkonium chloride, chloride 0.05 to 25 parts by weight of an activated sludge abnormal development inhibitor containing as a component at least one compound selected from the group of benzethonium per 100 parts by weight of dry solid content of activated sludge. A method for preventing abnormal phenomena in activated sludge.