JPH1133309A - Flocculant and flocculation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent lowering the treatment capability of activated sludge from deteriorating without generating sludge by using a specific flocculant when an oil content and a water component are separated from an oil-in-water type emulsion or a water-in-oil type emulsion. SOLUTION: This flocculant is expressed by formula R1 -Y and separates and flocculates an oil content and a water component from an oil-in-water type emulsion or a water-in-oil type emulsion. R1 is a compound residue containing a cationic group. The cationic group is preferably a group containing nitrogen tetrachloride such as an ammonium tetrachloride group, a pyridine tetrachloride group or an amino tetrachloride group. Y is a group expressed by formula -OSO3 M and M is hydrogen or a metallic element. The metallic element is preferably an alkali metal and for example, Na, K or Li can be pointed out. M is preferably Na or K which shows the high water solubility of a produced salt and a low industrial cost factor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flocculant, and more particularly to a flocculant and a flocculation method for separating and coagulating an oil component and a water component in an oil-in-water type or water-in-oil type emulsion.

[0002]

2. Description of the Related Art Water-based lubricating oils are frequently used in the steel making industry, the machining industry and the like. This water-based lubricant is nonflammable, inexpensive, non-toxic and safe, and has excellent cooling properties, viscosity change and compressibility as compared with petroleum-based lubricants. For this reason, it is frequently used as an oil-in-water type or a water-in-oil type emulsion for cutting oil, grinding oil and the like. As usage increases,
Waste water treatment of such aqueous lubricating oil or a liquid containing the aqueous lubricating oil has become important. Conventionally, as such a waste liquid treatment method, separation / aggregation using a flocculant is performed as a primary treatment. For example, an inorganic coagulant such as aluminum sulfate called a sulfuric acid band or polyaluminum chloride called a pack, or an organic coagulant such as a polyacrylamide polymer is added to waste lubricating oil to form an emulsion state. Breaks down and separates into oil and water components. The separated water component is further subjected to a secondary treatment such as an activated sludge treatment.

[0003]

However, when an inorganic coagulant is added as a primary treating agent, the pH of an aqueous lubricant is generally lowered in many cases, and it is necessary to neutralize the lubricant with an alkali such as caustic soda. However, there is a problem that the cost of processing chemicals increases as well as the cost.

[0004] Further, the amount of the inorganic coagulant to be added is large because it generates a large amount of colloidal particles and causes adsorption and precipitation.
As a result, there is a problem that a large amount of sludge is generated and sludge disposal cost increases.

Further, there is a problem that an inorganic coagulant adversely affects secondary treatment such as activated sludge treatment. For example, in the activated sludge process, if the remaining inorganic coagulant adheres to the activated sludge, it lowers the oxygen consumption rate of the activated sludge or causes partial demolition of the sludge, thereby lowering the activated sludge treatment capacity. Let it.

On the other hand, organic flocculants such as polyacrylamide-based polymers can be used in a small amount of 1/2 to 1/200 as compared with inorganic flocculants. There is a problem that the sludge treatment capacity is reduced.

SUMMARY OF THE INVENTION The present invention has been made to address such a problem, and when separating oil and water components in an oil-in-water type or a water-in-oil type emulsion, without generating sludge. Another object of the present invention is to provide a flocculant which does not reduce the treatment capacity of activated sludge in secondary treatment such as activated sludge treatment, and a flocculation method using the flocculant.

[0008]

The coagulant of the present invention is a coagulant represented by the general formula R ₁ -Y, which separates and coagulates the oil component and the water component of an oil-in-water type or a water-in-oil type emulsion. Wherein R ₁ is a compound residue containing a cationic group, Y is —OSO ₃ M, and M is hydrogen or a metal element. Here, the oil component and the water component refer to the components present in the oil layer in the oil, water, surfactants, stabilizers, pollutants, and the like that constitute the emulsion. The existing component is called a water component. Further, the compound residue containing a cationic group refers to the remaining portion of the compound containing a cationic group bonded to Y.

Further, the cationic group is a group having a quaternized nitrogen.

Further, the general formula R ₁ -Y is expressed as follows: 0.001 to 0.6
It is an organic polymer having an intrinsic viscosity of dl / g. Here, the intrinsic viscosity refers to the value measured at a temperature of 25 ° C by dissolving a sample in a 2 mol / l KBr aqueous solution.

Another coagulant of the present invention comprises a mixture of a compound represented by the general formula R ₂ -Y and a compound containing at least a cationic group, and comprises an oil-in-water or water-in-oil emulsion. A coagulant for coagulating an oil component and a water component, wherein R ₂ is an unsaturated bond residue of a hydrocarbon having at least an unsaturated bond in a molecule and a derivative thereof, and Y is a —OSO ₃ M group , Wherein M is hydrogen or a metal element. Here, the unsaturated bond residue refers to a portion excluding an unsaturated bond involved in the reaction, and specifically refers to a remaining portion to which at least Y is bonded.

The coagulation method of the present invention is a coagulation method for separating and coagulating an oil component and a water component of an oil-in-water type or a water-in-oil type emulsion. It is characterized in that any one coagulant is added.

The flocculant according to the present invention comprises a cationic group and-
Since it contains an OSO ₃ M group, it is easy to cause cross-linking and adsorption to the microfloc of the colloid particles, and it is easy to separate and aggregate the oil component and the water component in the emulsion. In addition, by setting the intrinsic viscosity to 0.001 to 0.6 dl / g, the influence on microorganisms in activated sludge can be reduced. In addition, since the emulsion component is separated using such a flocculant, generation of sludge after separation and subsequent activated sludge treatment become easy.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION R _{1 according to the} present invention is a compound residue containing a cationic group. Examples of the cationic group include a cationic group and a functional group having a low electron density. The cationic group is preferably a group having a quaternized nitrogen, and examples thereof include a quaternized ammonium group, a quaternized pyridine group, and a quaternized amino group.

An example of R ₁ is an organic group represented by the following chemical formula 1.

Embedded image

R ₃ represents hydrogen or a lower alkyl group, and hydrogen which gives more hydrophilicity is preferred in the present invention.
The term "lower alkyl group" refers to a linear or branched alkyl group having 1 to 4 carbon atoms. R ₄ represents a cationic group, and is preferably a group containing, for example, a quaternary ammonium salt or a tertiary amine. The group forming these is -CO
An NH ₂ group or a derivative group thereof can be mentioned.
Further, it may be a derivative group of a -COOH group. These derivative groups are groups in which a hydrogen atom of an amide group or a carboxyl group is substituted, and examples thereof include the following functional groups.

-CONHCH ₂ OH, -CON (C
_{H 3) 2, -CONHCH 2 OCH} 2 CH (C
_{H 3) 2, -CONHCH 2 CH} (CH 3) 2 CH 2 S
_{O 3 H, -CONHCH 2 C (} CH 3) 2 CH 2 SO 3
_{H, -CONHC (CH 3) 2} CH 2 SO 3 H, -CO
OCH ₂ CH ₂ N (CH ₃ ) ₂ , —COOC ₂ H ₄ N ⁺
(CH ₃ ) ₃ Cl ⁻ .

Further, R ₁ may be a copolymer containing at least one unit represented by the following chemical formula 2 in a polymer chain.

Embedded image R ₅ represents the same hydrogen or lower alkyl group as in Chemical formula 1,
R ₆ represents a carboxyl group, an alkoxyl group, an amino group, a sulfo group, a group having these functional groups at the terminal, and a derivative of these groups. The unit having R ₆ is obtained, for example, by copolymerizing a vinyl monomer. Examples of such a vinyl monomer include acrylic acid, methacrylic acid, n-butyl acrylate, 2-methoxyethyl acrylate, and 2-ethoxyethyl. Acrylate,
Acrylic acids such as dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, quaternary dimethylaminoethyl ester acrylate, styrenesulfonic acid, ethylenesulfonic acid, 2-acrylamide- Sulfonic acids such as 2-methylpropanesulfonic acid and the like can be mentioned. Among these, acrylate or methacrylate components, which are inexpensive and easy to use industrially, are preferred as copolymer components.

Y is a group having a general formula of —OSO ₃ M, where M represents hydrogen or a metal element. The metal element is preferably an alkali metal, and examples thereof include Na, K, and Li. Preferred examples of M include Na and K, which have high water solubility of the produced salt and are industrially inexpensive. By having such a -OSO ₃ M group, an oil component and water component in the emulsion is easily separated, it is possible to agglomerate, does not adversely affect such as activated sludge in the secondary treatment.

The flocculant represented by the general formula R ₁ -Y is preferably a high molecular weight substance, and the polymerization degree thereof is preferably an intrinsic viscosity of 0.001 to 0.6 dl / g. By selecting the degree of polymerization that the intrinsic viscosity is in this range,
It can exhibit the same effects as those of the -OSO ₃ M group.

The coagulant represented by the general formula R ₁ -Y can be used, for example, in water and a hydrophilic solvent such as methanol or ethanol, for example, a monomer having quaternized nitrogen alone or an acrylamide monomer or an acrylate ester monomer. by copolymerizing by a method such as a redox polymerization or radical polymerization in a state of peroxodisulfate such as peroxodisulfuric acid potassium (K ₂ S ₂ O ₈₎ is present in a large amount, introduced -OSO ₃ M group at the molecular end can do. Thus, the present invention is to always added to the end groups -OSO ₃ M group, used in a large amount than the reaction initiator concentration peroxodisulfate such as peroxodisulfuric acid potassium (K ₂ S ₂ O ₈₎ . Specifically, it is preferable to add about 0.3 to 1% by weight based on the total amount of monomers.

The -OSO ₃ M group may be contained not only at the molecular chain end but also as a side chain in the molecular chain as described above. When a —OSO ₃ M group is introduced as a side chain into the molecular chain, a compound having a double bond in the main chain as R ₁ is used, and potassium peroxodisulfate (K ₂ S ₂ O
It is obtained by reacting peroxodisulfate or sulfuric acid such as ₈ ). In this case, it is preferable to react the peroxodisulfate, such as about an equal molar amount of peroxodisulfate potassium (K ₂ S ₂ O ₈₎ with respect to the double bond.

Another coagulant of the present invention is a mixture of a compound represented by the general formula R ₂ -Y and a compound containing at least a cationic group. The general formula R ₂ is a portion obtained by removing at least a hydrocarbon having an unsaturated bond in a molecule and a derivative thereof from the unsaturated bond involved in the reaction. By reacting the unsaturated bond portion with peroxodisulfate such as potassium peroxodisulfate (K ₂ S ₂ O ₈ ) or sulfuric acid,
It can be introduced -OSO ₃ M group as a Y in the molecule. Examples of the starting material for R ₂ include unsaturated fatty acids and aliphatic hydrocarbons having an unsaturated group. Unsaturated fatty acids include myristoleic acid, palmitoleic acid, oleic acid, elaidic acid, cis-vaccenic acid,
Vaccenic acid, erucic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, sardine oil, docosahexaenoic acid and the like can be mentioned. Examples of the aliphatic hydrocarbon having an unsaturated group include unsaturated higher alcohols corresponding to unsaturated fatty acids.

Y is a group having the general formula —OSO ₃ M. This Y is formed by reacting an unsaturated group of R ₂ with sulfuric acid or a peroxodisulfate such as potassium peroxodisulfate (K ₂ S ₂ O ₈ ) to form —OSO ₃ M in the molecule.
Groups can be introduced. Specifically, a peroxodisulfate such as potassium peroxodisulfate (K ₂ S ₂ O ₈ ) is added in an amount of 0.01 to 1.5 moles per mole of the monomer having an unsaturated group, and is added at 50 to 80 ° C. It is obtained by raising the temperature and reacting for 2 to 8 hours.

The compound containing at least a cationic group mixed with the compound represented by R ₂ -Y includes a polymerizable compound containing a cationic group in the main chain or side chain. As the cationic group, a group having a quaternized nitrogen is preferable, and examples thereof include a polymer of dimethylamine and epichlorohydrin and a polymer having a quaternized nitrogen in a side chain. The molecular weight of such a polymer is preferably a molecular weight that does not inhibit the activity of the activated sludge in the secondary treatment. When the molecular weight is small, the bactericidal property of the cationic group is exhibited, and the activated sludge may be destroyed. Specifically, the intrinsic viscosity of the compound containing a cationic group is preferably from 0.001 to 0.6 dl / g.

The thus obtained flocculant of the present invention can be used as a solid after removing the solvent at the time of the synthesis reaction, or can be used as water or a hydrophilic solution.

The addition amount of the flocculant of the present invention varies depending on the state of the emulsion, but it is 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the total amount of the suspended substance and the dissolved sludge substance in the emulsion. Preferably it is 0.1 to 3% by weight. When the added amount is within this range, the oil component and the water component can be easily separated easily, and the amount of sludge generated after separation / aggregation can be suppressed to a small amount.

The method of addition is not particularly limited. For example, when the stirring of the agglutination reaction tank is strong, it can be used as a powdery or high-concentration undiluted solution, and when the stirring is weak, it can be used as a diluted solution. Examples of the diluting solvent include water, a hydrophilic solvent, and a mixed solvent of water and a hydrophilic solvent.

The flocculants of the present invention can be applied to oil-in-water or water-in-oil emulsions. The emulsion may be a stock solution before use or a waste solution after use, for example, a wastewater containing a dissolved sludge substance. Specifically, general food wastewater, painting wastewater, machine oil wastewater, mechanical wastewater, individual food wastewater, coolant wastewater, colored wastewater, oil-containing wastewater, dyed wastewater,
Examples include papermaking wastewater, latex wastewater, surfactant-containing wastewater and the like.

[0030]

【Example】

Example 1 stirrer, reflux condenser, sealed reaction vessel equipped with a thermometer and the like, in an aqueous solution 5 liter containing peroxodisulfate potassium _{(K 2 S 2 O 8)} 0.02 mole, dimethylaminoethyl acrylate methyl chloride Monomer [(CH ₂ ＣＨCHCO
5 mol of OC ₂ H ₄ N ⁺ (CH ₃ ) ₃ Cl ⁻ ] and 1 mol of methyl acrylate monomer were charged in order, and the reaction was carried out at 50 ° C. for 8 hours while keeping the inside of the reaction vessel under a nitrogen atmosphere. The obtained reaction product was dropped into a large amount of acetone to obtain a white powdery polymer. As a result of dissolving this polymer in a 2 mol / l KBr aqueous solution and measuring the intrinsic viscosity at a temperature of 25 ° C.,
The intrinsic viscosity was 0.40 dl / g. This polymer contains -OSO ₃ K group at the molecular terminal is a polymer containing a cationic group quaternized nitrogen in the molecule chain.

Example 2 A sealed reaction vessel equipped with a stirrer, a reflux condenser, a thermometer and the like was charged with 5 liters of an aqueous solution containing 0.02 mol of potassium peroxodisulfate (K ₂ S ₂ O ₈ ), and added with dimethylamino acrylate. Ethyl methyl chloride monomer [(CH ₂ ＣＨCHCO
^{_{OC 2 H 4 N + (CH}} 3) 3 Cl -] while keeping turn were charged reaction vessel 5 moles nitrogen atmosphere and reacted for 8 hours at 50 ° C.. The obtained reaction product was dropped into a large amount of acetone to obtain a white powdery polymer. This polymer is
The intrinsic viscosity was 0.30 dl / g as a result of dissolving in a 2 mol / l KBr aqueous solution and measuring the intrinsic viscosity at a temperature of 25 ° C. This polymer contains -OSO ₃ K group at the molecular terminal is a polymer containing a cationic group quaternized nitrogen in the molecule chain.

Example 3 Dimethylaminoethyl methyl acrylate monomer [(CH ₂ ＣＨCHCOOC ₂ H ₄ N ⁺ (CH ₃ ) _3]
Cl ^-] dimethylaminoethylmethacrylate methyl chloride monomer in place of _{[(CH 2 = C (CH} 3) CO
A coagulant was obtained in the same manner as in Example 2 except that OC ₂ H ₄ N ⁺ (CH ₃ ) ₃ Cl ⁻ ] was used.

Example 4 A 5 ml aqueous solution containing 0.02 mol of potassium peroxodisulfate (K ₂ S ₂ O ₈ ) was placed in a closed reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, and the like. Ethyl methyl chloride monomer [(CH ₂ ＣＨCHCO
3 mol of OC ₂ H ₄ N ⁺ (CH ₃ ) ₃ Cl ⁻ ], dimethylaminoethyl methyl chloride methacrylate monomer [(CH ₂ ＣC (CH ₃ ) COOC ₂ H ₄ N ⁺ (C
H ₃ ) ₃ Cl ⁻ ] was added in order, and the reaction was carried out at 50 ° C. for 8 hours while keeping the inside of the reaction vessel in a nitrogen atmosphere. The obtained reaction product was dropped into a large amount of acetone to obtain a white powdery polymer. As a result of dissolving this polymer in a 2 mol / l KBr aqueous solution and measuring the intrinsic viscosity at a temperature of 25 ° C.,
The intrinsic viscosity was 0.35 dl / g. This polymer contains -OSO ₃ K group at the molecular terminal is a polymer containing a cationic group quaternized nitrogen in the molecule chain.

Example 5 282 g (1 mol) of oleic acid was placed in a closed reaction vessel equipped with a stirrer, reflux condenser, jacket-type condenser, thermometer and the like.
And 200 g of sodium benzenesulfonate,
While maintaining the inside of the reaction vessel in a nitrogen atmosphere, 270 g (1 mol) of potassium peroxodisulfate (K ₂ S ₂ O ₈ ) was charged, and 1
After reacting at 5 ° C. for 5 hours, the mixture was neutralized with potassium hydroxide to obtain a solution 1. On the other hand, 50% by weight of dimethylamine
100 g of the aqueous solution was charged into a closed reaction vessel equipped with a stirrer, reflux condenser, thermometer, etc., and 102 g of epichlorohydrin was gradually added while maintaining the inside of the reaction vessel in a nitrogen atmosphere while maintaining the temperature at 30 to 80 ° C. Thus, solution 2 was obtained. Solution 1 and solution 2 were mixed at a weight ratio of 1: 1 to obtain a flocculant.

Example 6 8 kg of a 30% by weight aqueous solution of the white powdery polymer obtained in Example 1 was added to 5 m ^{3 of} waste water containing a coolant renewal liquid (containing 100 kg of oil), and the mixture was stirred for 10 minutes. Let stand for hours. The mixing ratio of the flocculant obtained in Example 1 was
2.4% by weight. The oil separated into an upper layer by standing.
The oil was separated, and the amount of normal hexane extracted from the aqueous layer was measured. The amount of waste oil generated is 250
Liters. On the other hand, when using aluminum sulfate as a comparative example, the amount required for processing is 100 kg, floating scum is waste oil-containing sludges 4 m ³ occur, even when dried
950 kg of dewatered cake was generated.

Next, the water layer from which the oil was separated was mixed with domestic wastewater, led to an activated sludge tank, and subjected to secondary treatment under the following conditions. The BOD of the mixture was 680 ppm and the COD was 360 ppm
, SS value was 120 ppm. Primary treated water from which oil was separated 1 m ³ / hour Aeration tank capacity 350 m ³ Return sludge amount 5 m ³ / hour Activated sludge concentration (meaning dry solid content with respect to wastewater) 5000 ppm Aeration amount 15 m ³ / min Activated sludge treatment time 36 hours No change was observed in the activated sludge after the treatment, and the activated sludge could be used continuously. The BOD of the treated water is 9ppm
, COD was 14 ppm and SS value was 5 ppm.

Example 7 Except for using the coagulant obtained in Example 2 in place of the coagulant obtained in Example 1, in the same manner as in Example 6, wastewater containing a coolant renewal liquid (containing 100 kg of oil) Was performed. The normal hexane extract of the aqueous layer was trace, and the BOD, COD, and SS values after activated sludge treatment were all 15 ppm or less.

Example 8 Except for using the coagulant obtained in Example 3 in place of the coagulant obtained in Example 1, the wastewater containing the coolant renewal liquid (containing 100 kg of oil) was used in the same manner as in Example 6. Was performed. The normal hexane extract of the aqueous layer was trace, and the BOD, COD, and SS values after activated sludge treatment were all 15 ppm or less.

Example 9 Except for using the coagulant obtained in Example 4 in place of the coagulant obtained in Example 1, wastewater containing a coolant renewal liquid (containing 100 kg of oil) was used in the same manner as in Example 6. Was performed. The normal hexane extract of the aqueous layer was trace, and the BOD, COD, and SS values after activated sludge treatment were all 15 ppm or less.

[0040]

The flocculant of the present invention is represented by the general formula R ₁ -Y, wherein R ₁ is a compound residue containing a cationic group.
Is a —OSO ₃ M group, and since M is hydrogen or a metal element, cross-linking and adsorption to microflocs of colloidal particles are likely to occur, and an oil component and a water component in an emulsion without generating a large amount of sludge. Has excellent separation / aggregation ability.

Further, since the cationic group has a quaternized nitrogen, the addition of a small amount of the cationic group easily causes cross-linking adsorption to the microfloc of the colloid particles.

Further, when the general formula R ₁ -Y is 0.001 to 0.6,
Since it is an organic polymer having an intrinsic viscosity of dl / g, in addition to the above-mentioned effects, the influence on microorganisms in activated sludge in the secondary treatment can be reduced.

The coagulant of the present invention comprises a mixture of a compound represented by the general formula R ₂ -Y and a compound containing at least a cationic group, wherein R ₂ has at least an unsaturated bond in the molecule. It is an unsaturated bond residue of a hydrocarbon or a derivative thereof. Since Y is a —OSO ₃ M group and M is a hydrogen or a metal element, cross-linking and adsorption to microflocs of colloidal particles are easily caused. It has excellent ability to separate and coagulate oil and water components in emulsion without generating sludge. Further, in the activated sludge treatment in the secondary treatment, the activated sludge treatment capacity is not reduced.

In the coagulation method of the present invention, since the coagulant described above is used, the oil component and the water component in the emulsion can be easily separated and coagulated, and the subsequent treatment with the activated sludge method becomes extremely easy. .

Claims (5)

[Claims] 1. A coagulant represented by the general formula R ₁ -Y, which separates and coagulates an oil component and a water component of an oil-in-water type or a water-in-oil type emulsion, wherein R ₁ is a cationic group a compound residue containing, in the Y is -OSO ₃ M group, coagulant, wherein said M is hydrogen or a metal element. 2. The flocculant according to claim 1, wherein the cationic group is a group having a quaternized nitrogen. 3. The method according to claim 1, wherein said general formula R ₁ -Y is 0.001 to 0.6 d.
3. The coagulant according to claim 1, wherein the coagulant is an organic polymer having an intrinsic viscosity of 1 / g. 4. An oil-in-water type or water-in-oil type emulsion comprising a mixture of a compound represented by the general formula R ₂ -Y and a compound containing at least a cationic group. An aggregating agent for aggregation, wherein R ₂ is the unsaturated bond residue of a hydrocarbon having at least an unsaturated bond in the molecule and a derivative thereof;
Wherein Y is -OSO ₃ M group, coagulant, wherein said M is hydrogen or a metal element. 5. An aggregation method for separating and aggregating an oil component and a water component of an oil-in-water type or a water-in-oil type emulsion, wherein the oil-in-water type or the water-in-oil type emulsion is provided. A coagulation method, characterized by adding the coagulant according to any one of (4) to (4).