JPS5942009A - Treatment of oil-containing waste water - Google Patents

Abstract

PURPOSE:To treat quickly oil-contg. waste water which contains fine oil droplets by adding a water soluble neutral polymer contg. >=1 kind among hydroxyl, amino and ether groups to said waste water and passing air through the waste water to form foams. CONSTITUTION:A water soluble neutral polymer contg. >=1 kind among hydroxyl, amino or ether groups, for example, methyl cellulose, PVA, polyvinyl pyrrolidone, polyethylene oxide or the like is added into oil-contg. waste water. At the same time, air is passed in the waste water to form foams. Then oil drops gather and float in the upper part even in the oil-contg. waste water which contains about <=10mu oil drops and the transparent treated water is quickly obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Regarding the process, more specifically, a minute amount of a polymeric oil/water separating agent on the order of ppm is added to oil-containing water, or a polymeric oil/water agent (h) (formed into any shape coated with agent i) is added. The body is immersed in the JJ water, and then the drainage is aerated,
The present invention relates to a method for rapidly separating, coagulating, and removing oil in oil-containing wastewater by bringing the obtained bubbles into contact with the wastewater.

Conventionally, the main method for oil-containing soap and water treatment has been to float and separate the oil by gravity, and oil-water separators based on the API and CPI methods have been used, but these methods have limited the diameter of oil droplets that can be treated. The limit is 7,008 m to 30 II m or more. Even smaller oil droplets are subjected to coarsening treatment through a coalescer, but in this case, the lowest limit of the number of oil droplets that can be removed is /θIt pn. Adsorption methods can be used to remove oil droplets smaller than this size, but the drawbacks of adsorption methods are that the ability of the adsorbent is limited and it takes time to reach adsorption equilibrium. According to this, the lower limit of 7d for oil droplets that can be removed by adsorption is 3/Z m, and oil droplets smaller than that are not absorbed at all and are completely colored. :, As for the floating method, in the case of chemical-free injection, the oil removal efficiency of 7;) is 7.
The limit is 0 to gθ. Meets wastewater standards with rmer: Meets regulatory values / Komeni f/, t, historical biological treatment, flocculation treatment with coagulants''! In either case, the method is to add 11 or pass through an activated carbon adsorption layer, which requires large equipment, long processing time, and high processing costs. At present, there is a great need for a rapid and energy-saving treatment method.

In response to the above requests, the present inventors solved the problems of conventional processing. I
With the aim of developing rapid treatment for oil-containing wastewater containing oil droplets of 711 or less, we have conducted intensive research to develop a method for rapidly treating oil-containing wastewater containing oil droplets of 711 or less. Are you concerned about the water-soluble neutral polymers it contains? The present invention was completed based on the discovery that the present invention has excellent oil-water separation ability in the presence of silica.

The present invention uses a micrometer on the order of ppm to add a polymeric oil-water separating agent to blow bubbles into oil-containing wastewater. The present invention provides a method for treating oil-containing wastewater that can almost completely treat fine oil droplets with a particle size of about /Itm.

Furthermore, in the present invention, a molded article of any shape coated with the above-mentioned polymeric oil-water separating agent alone or together with other materials is immersed in oil-containing wastewater, and then air is poured into the wastewater. The purpose is to provide a method for treating oil-containing wastewater that can achieve the same effects as those described above by blowing the oil into the oil-containing wastewater. 7 of them or 2 fjf
A group of water-soluble neutral polymers containing f or more can be used alone or in combination. Particularly useful polymeric oil-water separating agents include cellulose m-conductor hydroxyethylcellulose, methylcellulose, and polyvinyl alcohol (PVA), which is a vinyl polymer, as a group containing hydroxyl groups.
). Also, as a group containing an amino group, there is polyvinylpyrrolidine (PVI) containing a tertiary amine group. Assuming that the ether group is 7s-b i, I? Liethylene oxide, 7? There is ribinyl methyl ether. The basis of stationery/species-Jyu included tr+/! f: and L~,
Proteins, especially gelatin, and alsimi/gaagemo, IL
Ru. In addition, iI? used as a normal processing agent? Reacrylamide-based anionic polymer, carbon 7-ionic polymer flocculant, and carpogysimethyl cell L7-su (
CMC), polyacrylic acid sodium chloride, Kasano Takabuncho-1
Coagulants (l) are completely ineffective, and the present invention provides a completely new water treatment agent that is different from the previous ones. By adding / to /θ ppm, preferably λ ~ g ppn + and passing through air bubbles, the oil immediately starts to float and separate, and depending on the oil concentration of the oil-containing wastewater, it takes 5 to 30 minutes, usually for 5 to 30 minutes. -&ishi/3-separated VCfl:t
The fat and oil are completely removed.

The gas used for ventilation can be any selected from air, nitrogen, and oxygen, and the effectiveness of any of them varies greatly, so it is usually easier to achieve the purpose by using air. can. As the color generating plate, d: sintered glass powder, sintered metal powder, individual nozzles, and nozzle aggregates can be used. The diameter of a sphere with the same volume as this, that is, the equivalent diameter, is preferably in the range of / to gmm, and furthermore, / to gmm? The most preferable conditions are to generate bubbles in the range of n7+1. According to the research conducted by the present inventors: If the bubbles fall within the range of the MaJ method mentioned above, the oil-water separation rate increases with the number of bubbles generated and is almost unrelated to the bubble size, so if the bubble size is large. 1: It is necessary to increase the ventilation amount by that amount.

If a constant air bubble generation plate is used, the oil/water separation rate will increase as the aeration rate increases, or if the aeration rate exceeds a certain aeration rate that is not inherent to the air bubble generation plate, the oil/water separation rate will actually decrease. 7. It is necessary to select an appropriate ventilation amount, and the air superficial velocity usually used is 0.2 to 11. It is preferable that cIn/S1 is in the range of 2σ/s to 2σ/s.

When actually separating oil-water from oil-containing wastewater, it is preferable to disperse the air bubbles uniformly within the entire internal volume of the liquid. old tit
Since f speed becomes slow, 1 yen 1 kishiki, -, 1 is added to this point.
: By choosing the air superficial velocity of NLJ, the volume h1 can be determined.

It is also possible to carry out the treatment by continuous operation, but it is necessary to maintain an oil removal rate of 99 or higher.
The tank type is insufficient, and it is preferable to adopt the Ω or 3-ji type.

- Apply polymeric oil/water separating agent according to the treatment conditions described in / or /
If Op p m is added and aeration is performed, it will last for 5 to 30 minutes.
Usually, the liquid is clarified in about 7θ minutes, and it is possible to suppress the residual oil content to below the regulatory value of 5 ppm, and the method of the present invention can be said to be an unprecedentedly rapid and efficient method.

The method of the present invention is most suitable for treating wastewater in which petroleum oils such as light oil, A heavy oil, 13 heavy oil, and C heavy oil are dispersed.

In addition, if the oil-containing wastewater contains solid content (SS), the SS is 50p.
If it is below pm, it is possible to float SS and oil at the same time. When a large amount of SS is contained, it can be treated by the method of the present invention, followed by filtration, or by adding a polymer flocculant and causing sedimentation.

When a surfactant is mixed in the oil-containing wastewater, the influence of the cationic surfactant is not large, but the anionic surfactant VC can be treated as is if it is mixed in at a level of tppm or more. Contamination beyond this level can be treated by adding sulfuric acid or the like after adding the polymeric oil-water separating agent of the present invention. In this case, it is preferable to add the polymeric oil/water separating agent before or at the same time as the sulfuric acid band; if the sulfuric acid band is added before the polymeric oil/water separating agent, the effect of the polymeric oil/water separating agent will be reduced. Therefore, care should be taken in the order of addition.

Furthermore, when treating oil-containing wastewater colored by dissolving humic acid in the soil, oil and humic substances can be removed at the same time by the same treatment as when a surfactant is mixed.

The action mechanism of the polymeric oil-water separating agent of the present invention is as follows:
tg light:Σ9ru. That is, polymer oil water t dissolved in water C
'The hydrophobic part in the molecule of the fltl agent sticks to a fine oil droplet V, 1L, resulting in f, (,, 7 The cross-linking of the species takes place)tll: )1 By colliding with the air 2fu, the entanglement of the polymers with a large number of oil droplets is promoted. ′ are close together, many oil droplets coalesce, and then 1. It can be said that the result is that when the bubbles reach the water surface, oil + W is left behind on the water surface. The effect of the method of the present invention is exhibited in minute oil droplets rather than coarse oil droplets, and when measuring the oil-water separation rate based on the particle size of the oil droplets, it is compared to the case where no polymeric oil-water separation agent is added. , /~:l It 7710 oil drop 6:t
/ 00 times faster, compared to 10-/,! ; With an oil droplet of l1m, rt/θ is multiplied and the humidity becomes faster. Therefore, overall, the method of the present invention does not depend greatly on the size of the oil droplet diameter;
This enables quick oil/water separation.

Regarding the method of adding the polymeric oil/water separating agent as a solution, as another embodiment of the present invention, the oil/water separating agent can be added to the liquid in solid form. In other words, a polymer oil-water separator is mixed with a water-based emulsion adhesive, and this is applied to an object of any shape and dried.The surface of the hardened adhesive is immersed in oil-containing wastewater. The polymeric oil-water separating agent mixed inside is gradually dissolved and leached out, and it is stirred by air bubbles and p
It is possible to obtain a result similar to that obtained by using a polymeric oil-water separating agent which gives a concentration on the order of p I'n and which has a small practical solution.

According to this method, there is no need to dissolve the polymeric oil-water separating agent, and it can be mixed with the powdered sweet emulsion noyon adhesive and applied, so it can be said to be an extremely simple method. In other words, it is difficult to prepare an aqueous solution of the polymer oil-water Pfln agent because it gives a high viscosity. Therefore, when adding the polymer oil-water separation agent as a solution, the liquid is This is somewhat expensive, and there is a drawback in terms of transportation costs.

On the other hand, if it is added as a solid, there is no need to re-add it once the polymeric oil-water separation agent loses its activity, and it is easy to use, especially when processing small to medium-sized J or TT models (in this case, there is no need for a chemical addition device). Also, is it the same as the emulsion adhesive and the product?
: When mixing l# agent, use sodium chloride sulfate and triuno 21. as a dispersion aid. -1? It is convenient to mix salts such as sodium lyphosphate or aluminum salts because it is possible to control the degree of elution of the polymeric oil-water separating agent or suppress the action of the surfactant. be.

The aqueous emulsion used in the present invention can be used as an adhesive, but if it is water resistant or large, it will be contained inside the coating layer. Since leaching of the agent becomes difficult, in this case, it is desirable to spray the oil-water separating agent on the adhesive-coated surface and dry it. Adhesives with moderate water resistance include polyvinyl acetate, copolymers of vinyl acetate and vinyl chloride, and emulnoyon adhesives based on polyvinyl acetate, including terpolymers of vinyl chloride and ethylene. most preferred. After dispersing the above-mentioned polymer oil/water separation agent in powder form into this Emulnoyon adhesive, adding and mixing salt, sodium sulfate, thorium phosphate, etc. as a dispersant as necessary, and applying it to a material of any shape. , MFT or higher, an oil-water separating agent that is convenient to use can be obtained.

The material to be coated and the shape can be selected arbitrarily; synthetic resin, metal, natural fiber, comb, etc. can be selected as the material, and the shape can be flat, linear, fiber etc. You can choose from shapes, paper shapes, net shapes, and three-dimensional structures using these as constituent elements. As another embodiment, it is also possible to use a tablet-shaped product in which only the composition consisting of an adhesive, a polymeric oil/water separator, and a dispersion aid is solidified without being applied to other objects.

1. After the leaching of the active ingredients is completed, the above-mentioned material can be collected from the wastewater treatment equipment, washed, and reapplied for repeated reuse. In some cases, it can be incinerated after removal. It is also possible. Further, in order to explain the present invention more specifically, Examples will be shown below. It should be noted that the present invention is not limited to such embodiments, but may be freely modified within the scope of the technical merits of the present invention.

Example 1iii/S giri, ・°I-distilled water/e,,A heavy oil/me
After processing, add 0.03 g of 1-ij 1 mouth] disodium and stir for 5 minutes.A rfj oil? rt Completely dispersed and cloudy oil-containing water is added. 1. i, As a result of the measurement of the degree distribution, the average particle diameter of this oil droplet i17 [O~g/1m
Then, with the oil droplet size distribution 1r, T, / -, 20/lnl (45) 1, add 300 ml of this oil-containing water to a glass column with a diameter of 0111111 using a G-3 glass filter at the bottom. ! The liquid was charged to form a liquid column of approximately qocm. Aerate through a glass filter at a flow rate of 7.00 me/min through an airflow meter regulator, while sample water is continuously taken out by a metering pump through a tube inserted into the ram and circulated into the column. ＝
Sample liquid was collected in a quartz cell of 0 mm square for a certain period of time (/ The time for each sample collection was determined by measuring the oil removal rate coefficient. using en(Or)) vs. time (
The value of ■( was calculated from the graph of ).

Using the above device, add the polymer oil-water separating agent of the present invention,
Table 1 shows the oil-water separation effect when aerated for 5 minutes.

Table / Separation effect table of oil-water separation agent / Indicated by Q J-, I Added sea urchin polymer oil-water separation υnl-
The OD of the 1/7θθ former 11 is about 01g, and the (f) conversion is not Σt1 (for l″C, the oil-water molecule of the present invention iiU agent metal 6 force 11 is OI)? θ～
θ, 0.2 of 11.10 V
do. In the case of +-IF white matter, which is the same as K-gelatin, the molecular shape of serum albumin is spherical1),
Moreover, the oil-water separation effect of polymer 18, which has fewer active groups in OHlN H chrysanthemum, is found to be less effective.
: I++・rsa l'Luderu）rou.

Table 1 shows the results of determining the oil removal rate 1 thread 1 (according to the apparatus and method shown in Example No. γ14/).

The value of K when no oil-water separating agent is used is 0 under the same conditions.
It is + at 0θ, 2.2, so 1. ．． Addition of about 2 ppm of oil/water separation agent ((This shows that the oil/water separation rate was increased by about 2SO to about /I-oo times by 1 step, and the oil/water N:IC agent of the present invention has a revolutionary oil/water separation rate It will be understood that this is a method that can increase the speed and allow extremely rapid processing.That is, by using the oil-water separation agent of the present invention (dispersion 11 of about 00 ppm) Cleaned within minutes, extracted 7 tM with 9 tetrachloride, 1 infrared portion) 1'S photometric vessel, 3.11-3.3 Oil content determined from absorption at 1 Lm g? Also θ~3
It was found that the water was within the ppm range, had no oily odor, was tasteless and colorless, and could be used as water for reprinting.

Table Ω For each treatment agent, L oil removal rate 1 series or 1-AX
Although it is well known that the effect of 5rl on jij ii is ζ, for comparison, we investigated its salt + 9 effect under 76 minutes of aeration and found that with the addition of salt (IS cal/tl, -2000pp p m)
The value of (-[θ, θ, 2, JAA (IS Thorium 7S
When θ0 ppm is added, c], 0.23, and j, ?
11 "(:■(
111i is 0.0 evening, and the salt level is about the same as seawater.
1! LG (:1.・Even if it is oily and moisture: no tt, a degree is /
About -0 min/((Zukisu, these small flames are the oil of the present invention) when adding (I, Ii) pp p m It can be said that this proves that the moisture 1iifi agent has been used as a bow mother store.

Actually,'・i! ! Example 7: Cut a slide glass for an enemy mirror into 4 widths and apply acrylic emulsion glue AT-41O to the lath 14.
(Showa Polymer r < r <'), and apply m (approx.・1 digit/
,,! Dry for S minutes in a drying oven at θ゛°C. This was prepared in the same manner as in Example/This is heavy oil dispersion A! ;0m
Put it in L, G,? Pass through a glass filter to generate air bubbles at a superficial air velocity of about 7 cm/s. After aeration for S minutes, the absorbance of '1100n of the sample relative was o,oot
7, and the ratio to the stock solution was 0.4 g%.

On the other hand, the sample solution treated with a glass piece prepared in the same manner except that hydroxyethyl cellulose was not used had an absorbance of /,
, 27, which was 93 times higher than that of the undiluted solution, and almost no removal effect was observed.

Implementation 1st month? Vinyl acetate emulsion jMa agent S -”θ
0 (Showa Polymer Kl(>U')) was mixed with about 0./wt% of polyvinyl alcohol (high quality name Niko-Senol N Hλ Otsu)17, and applied to a glass piece in the same manner as in Example 3. Then, after drying and drying, the A heavy oil dispersion test 4.1 was passed through the ventilation side for 10 minutes in the same way as in the method in 3. 07g
Reached K.

After applying the above adhesive to the coconut shell fibers and bonding and forming, / 0 Ri'C: 3! When the molded product is dried for i minutes and treated in the same manner as above, the absorbance of the treatment solution is o.
, oogg.

Example 5 Emulnoyon adhesive (trade name: Sumikaflex) consisting of a three-dimensional combination of ethylene, hinyl acetate, and hinyl chloride.
g30) about 0. / t% by weight of hydroxyethyl cellulose was mixed in a L, dried as it was, and dried to give a solution of about 1 [4 to about 3
The absorbance of the treated solution after cutting into mm squares, putting them into the same A heavy oil dispersion as in Example 3, and aeration treatment for /θ minutes was 0.
It was 0077.

Claims (4)

[Claims] (1) A water-soluble medium/j raw polymer containing 1(, amino group, or ether group) or 2 (:!Ii or more) in 3 oil wastewater (/ (add and aerate into the waste water to form air?CW) 4 yen +a
How to treat oil-containing 4F water. (2) An aqueous solution prepared by dissolving the neutral water-soluble polymer alone or in the form of a mixture is added to the oil-containing wastewater so that the concentration of the polymer is / or / Op p m. The method of patent + 'il'j search scope 17. (3) Claims 3 and 7 in which a structure coated with the neutral water-soluble polymer in powder form and a water-based emulsion adhesive in an arbitrary shape and material is brought into contact with the oil-containing wastewater.
Section method. (4) The method according to claim 17, wherein the composition comprising the neutral water-soluble polymer and the water-based emulsion adhesive in powder form is dried and solidified, and the solid material obtained is brought into contact with the oil-containing wastewater.