JPH02135257A - Novolak resin composition and treatment of waste water using the same - Google Patents

Abstract

PURPOSE:To obtain a novolak resin composition having excellent storage stability under high temperature and humidity condition and useful also as a treating agent for an emulsion waste water by uniformly mixing crushed novolak resin with a specific amount of bentonite. CONSTITUTION:The objective novolak resin composition is produced by uniformly mixing (A) crushed novolak resin having particle diameter of 1mum-5mm, preferably a resin soluble in alkaline water, more preferably a novolak resin of formula (n is 2-6) with (B) 3-25wt.% (based on the component A) of bentonite, preferably a sodium-type bentonite having particle diameter of <=50mum and containing particles of <=0.1mum in diameter accounting for 50-65wt.% of the bentonite. The mixing is carried out e.g., by a super-mixer. Waste water treatment is carried out by uniformly mixing the composition with an emulsion waste water in the presence of an alkaline substance and adding an acid to the mixture to precipitate the component A dissolved in the system and the component B dispersed in the system together with the suspending material in the waste water.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention uses bentonite as a novolac resin (hereinafter referred to as NR).
The storage stability of the N11 pulverized product is improved by mixing it with the pulverized product of NR (hereinafter abbreviated as E wastewater), and it is also useful as a treatment agent for emulsion wastewater (hereinafter abbreviated as E wastewater).
Composition.

The present invention also relates to an excellent method for treating E wastewater using the same.

<Prior art> Conventionally, NR has been commonly used as a molding material and a binder for grinding wheels, and a method of dissolving it in alkaline water to treat wastewater is also known. In order to facilitate this, NR is usually used after being ground.

However, when pulverized NR comes into contact with hot and humid air, it absorbs moisture and generates heat, causing the NR particles to fuse (fuse) and harden, turning into a lump that does not dissolve (melt) easily. be. Therefore, the crushed NR product should be stored in a container that can completely block air and stored at low temperatures.
Since it requires careful storage management, there is a strong demand for improvement.

On the other hand, the main components of E wastewater are synthetic organic substances that are difficult to decompose naturally (emulsion floaters, emulsion polymer oily substances, etc., 7-mer 1 surfactants, protective colloids, etc.). After removing synthetic organic matter through chemical treatment to lower the COD value (chemical oxygen demand), which indicates the degree of contamination, and creating a composition close to that of natural organic matter, biological treatment (treatment with activated sludge using microorganisms) is carried out. ) is carried out.

Conventionally, the above chemical treatment methods include adsorption filtration, which removes impurities in wastewater by adsorbing them to adsorbents (activated carbon, bentonite, etc.), and flocculants (polymer flocculants, inorganic salts, hydroxides, etc.). is added to coagulate impurities (coagulation, coagulation, adsorption, occlusion,
Coagulation-sedimentation separation method (Japanese Patent Laid-Open No. 52-39259
etc.) are known.

<Problems to be solved by the invention> However, the adsorption filtration method using a powdered adsorbent such as bentonite requires a filtration step and has drawbacks such as clogging of the filter medium and insufficient removal of COD components. There is.

Further, in the coagulation-sedimentation method using inorganic salts or metal hydroxides, even if a large amount of them is used, the emulsifier cannot be coagulated sufficiently, and there are drawbacks such as an increase in nonflammable substances.

On the other hand, in the method of JP-A No. 52-35259, when nonionic E wastewater' is treated using dichyadiamide diethylene polyamine-formaldehyde polycondensate (cationic polymer) and NR as a treatment agent, the supernatant becomes transparent, but the sedimentation rate of the aggregate is slow. And N
When using R alone to treat nonionic E wastewater,
The sedimentation rate becomes slow due to insufficient removal of COD components.

Furthermore, when cationic E wastewater is treated with this method,
With NR alone, the supernatant is opaque and the sedimentation rate is slow (C
If the removal of OD components is insufficient and the above-mentioned cationic polymer is used in combination, the electrostatic charge and the positive charge of the cationic component (cationic surfactant or emulsion polymer) in the wastewater will cause electrical repulsion. The flocculation effect is significantly reduced.

As described above, the effects of the treatment agent vary depending on the ionicity and components of the E wastewater, and no universal treatment agent has been found that can be applied to any case.

Among E wastewaters, especially cationic E wastewaters contain large amounts of nonionic surfactants and protective colloids in addition to the cationic components (mentioned above) that are difficult to remove.
It is difficult to easily remove these impurities, and the development of appropriate treatment agents and treatment methods is desired.

The present invention was developed in view of the above circumstances, and its purpose is to prevent the fusion, agglomeration, and other effects of N1 particles even if they come into contact with hot and humid air during storage. To provide a NR composition that is stable and useful as a treatment agent for E wastewater, and by using the NR composition as a treatment agent, sedimentation and separation of aggregates is quick and easy, and COD An object of the present invention is to provide an excellent treatment method for E wastewater that can improve the effect of removing components and purify it into a transparent supernatant.

Furthermore, another object is to provide an excellent method for stabilizing NR pulverized material and a wastewater treatment agent composition.

<Means for Solving the Problems> The above-mentioned object of the present invention is to provide a novolac resin composition comprising a pulverized product of novolac resin and bentonite particles in an amount of 3 to 25% by weight based on the weight of the pulverized product. Additionally, the above novolac resin composition is mixed with emulsion wastewater in the presence of an alkaline substance, and then an acid is added to precipitate the novolac resin dissolved in the system and the bentonite dispersed in the system. This is achieved by the above wastewater treatment method.

Namely, as a result of research into a method that can improve the storage stability of NR pulverized products, the present inventor found that (1) if NR pulverized products and a specific amount of bentonite are uniformly mixed, it will be possible to improve the storage stability of NR pulverized products. Even in an atmosphere, bentonite particles absorb moisture in the air (
(■) It is possible to sufficiently absorb air and expand to protect the NR pulverized material and prevent NR powder particle fusion (fusion) and agglomeration that occur due to high-temperature moisture absorption.

(2) It was confirmed that this N1 composition is stable and does not impair the properties of NR and bentonite even after long-term storage.

As a result of further research, we found that (1) this N1 composition is extremely useful as a wastewater treatment agent;

(2) Using this N1 composition as described above.

When E wastewater is treated, NR and bentonite have a high concentration Qf.
It also acts synergistically with liquid i, easily coagulating emulsifiers, protective colloids, and emulsion polymers, unifying them, quickly settling and separating them, and purifying them into a transparent supernatant liquid with a low COD (a). What you can do.

(3) Sedimented flocs are large, hard, and hydrophobic N
By R? Ti? 1i (or glued), so
Can be easily dehydrated.

(4) In this case, bentonite acts as an adsorbent for impurities, but for cationic impurities (cationic emulsifiers and emulsion polymers), its positive charge is neutralized by its inherent negative charge, and the electrostatic (forms a complex), promotes aggregation and sedimentation of both, and has a strong coagulation effect on nonionic impurities (nonionic emulsifier, protective colloid) and adhesive (bonding) effect between aggregate particles. In combination, cationic E wastewater can also be easily purified.

They discovered this and arrived at the present invention.

Hereinafter, embodiments of the present invention will be explained in detail.

The above-mentioned NR that can be used in the present invention is a product obtained by reacting (condensing) phenol and aldehyde in the presence of an acidic catalyst, and is preferably soluble in alkaline water, more preferably the following formula ( This is a novolac resin with the structure shown in 1).

i? The pulverized NR in item i includes powder, granules, flakes, or similar materials obtained by pulverizing NR,
It is desirable that the particle size is lu to 5 mm.

Bentonite that can be used in the present invention is a clay whose main component is montmorillonite, a clay mineral. Sodium bentonite is preferred from the viewpoint of water absorption, adsorption power, binding strength, dispersibility, etc. Sodium-type bentonite has exchangeable cations mainly sodium, with 2%
It is preferable that the pH of the suspension water is 8.5 to 11.

The particle size of bentonite is 50μ or less and 0. It is preferable that 50 to 65% of particles are 1 μ or less in size.

The N1 composition of the present invention is a mixture of NR and bentonite.
II (for example, free mixer, super mixer, etc.). The mixing ff1 (amount used) of bentonite is 3 to 25 weight based on the weight of NR. If the amount is less than 3% by weight, the storage stability of NR cannot be sufficiently improved, and when the mixture is used as a wastewater treatment agent, the above object cannot be achieved.

If more than 25% by weight is mixed, the storage stability is good, but when used as a wastewater treatment agent, the supernatant liquid may become cloudy or the sedimentation rate may be slow.

The N1 composition of the present invention is extremely useful as a treatment agent for various wastewaters, as a molding material, as a binder for grindstones, and the like.

E wastewater in the wastewater treatment method of the present invention refers to synthetic resins (vinyl polymers, polyolefin resins, polyurethane resins, epoxy resins, petroleum resins), synthetic rubber, natural rubber,
This is wastewater in which oily substances such as natural PA fats, fats and oils, and their analogues are emulsified and dispersed. These E wastewaters usually also contain emulsifiers such as surfactants and protective colloids (water-soluble polymeric substances).

The above-mentioned uniform mixing of the NR composition of the present invention with E wastewater in the presence of an alkaline substance means (1) adding and mixing the NR composition to an aqueous solution of an alkaline substance to dissolve NR and disperse bentonite; Prepare a liquid and mix this liquid with E wastewater. (2) E After dissolving the alkaline substance in wastewater, add and mix the NR composition to this wastewater to dissolve NR and disperse bentonite. (3) or E
This means that after mixing the wastewater and the NR composition, an alkaline substance is added thereto to dissolve the NR and disperse the bentonite.

The alkaline substances include alkali metal hydroxides,
Examples include alkaline earth metal hydroxides, ammonia, and amines. Among these, sodium hydroxide and potassium hydroxide are preferred.

The amount of alkaline substance used is the amount necessary to dissolve NR in water (for example, the amount necessary for phenol in NR to produce sodium phenolate), but in order to precipitate NR by adding acid in a later step. The minimum amount required is desirable.

The amount of the NR composition used is preferably 3 to 50% by weight, more preferably 5% by weight based on the dry solid content in the E wastewater.
~40% by weight.

If it is less than 3% by weight, it will be difficult to achieve the above objective, and if it is used more than 50% by weight, the transparency of the supernatant after treatment may decrease.

As described above (after uniform mixing, NR is dissolved in the system, and bentonite is uniformly dispersed and coexists with the emulsifier, protective colloid, emulsion polymer, etc. in the E wastewater).

Add acid to this mixed system to adjust the pH to 8 or less, preferably 7.
．． When the temperature drops to 5 to 6.5, NR becomes insolubilized, bentonite becomes unstable, destroys the emulsion, and collects and integrates the emulsifier, protective colloid, emulsion polymer oil, etc. in the wastewater (flocs). and precipitate. When left to stand still, the flocs grow thick (and quickly settle), clearly separating from the clear supernatant liquid and depositing at the bottom of the treatment tank.

The amount of acid added is the necessary amount to insolubilize NR, but it is necessary to lower the pH of the system to 8 or less, preferably 7.5 to 6.5 in advance, to improve the sedimentation rate, floc size, and stability. ,
It is desirable to determine the optimum amount by examining the transparency of the supernatant liquid, etc.

In the treatment method of the present invention, not only suspended matter such as emulsion polymers and oils and fats, but also water-soluble polymers (protective colloids) and surfactants (nonionic, cationic, anionic, and amphoteric) , and can be purified to a clear supernatant liquid containing almost no dry solids. The flocs produced by agglomeration are a mixture of suspended matter, emulsifiers, protective colloids, etc. in wastewater, bentonite particles, and NR, and are heavy, large, and coated with NR, which has high adhesive strength and hydrophobicity. Because of this, it is not only easy to drain or settle, but also has a low water content and can be easily dehydrated. And Kamisumi is
Since it is transparent and has a low COD content and reduced BOD content, it may be possible to dispose of it as is, and as described above (biological treatment can be used to smoothly and easily remove BOD components). can.

Incidentally, preferred embodiments of the present invention are as follows.

(1) The NR composition according to claim (1).

(2) The wastewater treatment method according to claim (2).

(3) The NR composition according to claim (1), wherein the NR composition is a treatment agent for emulsion wastewater.

(4) The N1 composition according to claim 1, wherein NR is represented by the following formula (1). The method for treating wastewater according to claim (2), wherein the required amount is reduced to 6.5.

formula (2) Wastewater treatment method.

(5) The N1 composition according to claim (1), and the wastewater treatment method according to claim (2), wherein the pulverized NR has a particle size of 1 μ to 5 mm.

(6) The N1 composition of claims (1) and (7), wherein the bentonite is sodium-type bentonite. and claim (2)
wastewater treatment methods.

(7) The method for treating wastewater according to claim (1), wherein the amount of the N1 composition used is 3 to 50% by weight based on the dry solid content in the E wastewater.

(8) Acid addition 1 lowers the mixed system pH to 7.5 - <Example> The present invention will be described in detail below with reference to Examples.

In addition, parts shown in Examples means parts by weight, and % means weight % unless otherwise specified. In addition, storage stability, COD
The measurement and testing methods for removal rate, supernatant permeability, sedimentation rate, and dissolution rate were as described below.

(1) Storage stable powder sample (NR, mixture of NR and bentonite) 15
kg into a bag (breathable) made of polyethylene film, store the bag in a cardboard box, and store it at a relative humidity of 8.
5% and stored for one month in an atmosphere at a temperature of 35° C., the powder samples were examined for changes (fusion between particles, agglomeration, hardening).

(2) Dissolution rate (ease of dissolution) 20 parts of the sample of NR, NR-bentonite mixture (composition), etc. after the above storage stability test, and 80 parts of a 20% caustic soda aqueous solution (50°C) in a glass container. The mixture was placed in a container and stirred with a magnetic stirrer, and the time required for the NR to dissolve (hereinafter abbreviated as dissolution time) was measured.

(3) Measurement of COD and its removal rate COD was measured according to the method of J I 5-KO102, and the COD removal rate was calculated using the following formula.

COD removal rate (%) = (4) Transmittance of supernatant liquid Transmittance (%) of distilled water is expressed using a white light source using an EPO-B type optical photometer (manufactured by Hitachi).

(5) Sedimentation rate After the wastewater was treated, it was immediately transferred to a 500-meter measuring cylinder, gently inverted three times, and then stood still, and the scale at the interface with the supernatant liquid was read at regular intervals to determine the sedimentation rate.

Example 1 (1) Regarding the amount of bentonite powder mixed into the NR dressing powder, and the storage stability and dissolution rate (ease of dissolution) of the resulting mixture.

The particle size obtained by crushing with a free crusher is 0.18m.
To 100 parts of NR of m or less (80 mesh or less), 1 part of sodium bentonite (hereinafter abbreviated as SB), 3
parts, 5 parts, 8 parts, 10 parts, 15 parts, 20 parts, 25 parts, and 28 parts, respectively, were added and kneaded for 10 minutes in a super mixer to obtain each mixture (composition).

Next, the storage stability and dissolution time of each mixture and NH alone (SB-no addition) were compared. The results are shown in Table 1.

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Example 2 Washing wastewater of a seashore made of polyvinyl acetate emulsion polymerized using polyvinyl alcohol (hereinafter abbreviated as PVA) as an emulsifier (with a solid content of 30,000 ppm and PVA in it)
(3,000 ppm for COD, 9,000 ppm for COD) were added 2,100 ppm of each of the NR-3B mixture and NR alone obtained in Example 1, and 8,700 ppm of NaO was added under stirring.
m was mixed.

Note that the pH of the liquid was approximately 12. Next, while stirring, hydrochloric acid was added to adjust the pH of the system to 7, and then the mixture was heated to 500 c.
Transferred to graduated cylinder c. Then, it was allowed to stand still, and the sedimentation rate was measured, and the transmittance and COD removal rate of the supernatant after sedimentation were measured.

(Table 2) Next, as Comparative Example 4, instead of using NR alone in Comparative Example 1,
The wastewater was treated in the same manner using the same amount of SB alone. As a result, no clear separation was observed, and no effect on waste liquid treatment was observed.

As is clear from the above results, 38
By mixing 3% or more of the particles, it is possible to provide a high degree of storage stability that does not cause fusion (blocking), agglomeration, or solidification of the NR particles even in a high-temperature and humid atmosphere. The N1 composition containing 383 to 25% by weight exhibits a synergistic effect of the above two components, and has a high COD removal rate (quickly sediments and separates aggregates to form a transparent supernatant). can do.

The separated flocs were large, hard, and stable, and could be easily filtered out. In addition, the surface of the floc was coated with hydrophobic NR, and water drainage was good.

Example 3 Vinyl acetate-2-ethylhexyl acrylate copolymer emulsion wastewater emulsified and dispersed with a polyoxyethylene alkyl ether type nonionic surfactant and hydroxyethyl cellulose (protective colloid) was purified. This material has a solid content of 20,000 ppm and a transmittance of 1. O, COD was 9800 ppm. First, NaOH was added to this wastewater to adjust the pH to 11, and then a mixture of NR and SB with the composition shown in Table 3, or NR alone was added to the wastewater, and the mixture was uniformly mixed by stirring. In addition, the pH was set to 6.5, and after stirring was continued for a while, the mixture was allowed to stand, and the sedimentation rate was 1111 L in total, and the transmittance and COD of the supernatant after sedimentation were measured. The result is the third
Shown in the table.

Again, as Comparative Example 8, instead of NR alone in Comparative Example 5,
When the wastewater was purified in the same manner except for using SB alone, no clear separation into two layers was observed, and no treatment effect was observed.

As is clear from these results, a mixture of NR and 3 to 25% SB (NR composition of the present invention)
As in Example 2, the two components exerted a synergistic effect and showed a good treatment effect.

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COD was 9000 ppm.

After adding NaOH to the waste liquid and adjusting the pH to 11,
A mixture of NR (polymerization degree is 6) and SB having the composition shown in Table 4, and NR alone were added at 4400 ppm to the above wastewater,
Stir +11 to mix uniformly. Next, add hydrochloric acid while stirring to adjust the pH to 6.8. After continuing to stir for a while, let it stand and measure the sedimentation rate, and calculate the permeability and COD removal rate of the supernatant after sedimentation. It was measured. The results are shown in Table 4.

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As a result of the same wastewater purification process except that the same amount of SB alone was used, the COD removal rate was 30%, the supernatant permeability was 20%, and the sediment volume was 490 m 1.30 minutes after 5 minutes. Later it was 400ml after 460-160 minutes.

As is clear from this result, emulsion wastewater containing cationic polymers and cationic surfactants, which have been difficult to purify in the past, can also be used as both components in the mixture (composition) of NR and SB of the present invention. Due to the synergistic effect of the above, the COD removal rate is high (the aggregates can be rapidly separated by sedimentation and purified into a transparent supernatant).

Note that n (degree of polymerization) of NR in Example 1 is 5, and N in Example 3.
n of R is 4. The COD of the supernatant liquid was 2430 in Comparative Example 9, 180 in Examples 13 and 14 of the present invention, 90 in Examples 14 to 16 of the present invention, and 900 in Comparative Example 11.

The pH of the 2% suspension of SB was 1 in Examples 1 to 4.
It is 0.

<Effects of the Invention> As described above, the present invention significantly improves the storage stability of the novolac resin (NR resin) by mixing an appropriate amount of bentonite particles into the novolac resin (NR resin), and furthermore, the mixed SR composition can be used as an emulsion. It is extremely useful as a wastewater treatment agent.

According to the treatment method to which this is applied, the synergistic action of the two components allows the stably emulsified and dispersed polymer particles to be quickly sedimented and separated together with the surfactant and protective colloid, resulting in highly efficient COD removal. The separated flocs are thick (, hard), stable, and can be easily dehydrated and filtered, and their specific effects are remarkable.

Claims (2)

[Claims] (1) Pulverized novolac resin and 3
A novolak resin composition containing ~25% by weight of bentonite. (2) After uniformly mixing the novolac resin composition according to claim (1) with emulsion wastewater in the presence of an alkaline substance, an acid is added to the novolac resin composition dissolved in the system. A method for treating wastewater as described above, characterized by precipitating dispersed bentonite.