CA2023735C

CA2023735C - Compositions and process for removing toxic resin acids and derivatives from effluent

Info

Publication number: CA2023735C
Application number: CA 2023735
Authority: CA
Inventors: Robert Dennis Hodges; Timothy Paul Nickel
Original assignee: Raisio Chemicals Canada Inc
Current assignee: Raisio Chemicals Canada Inc
Priority date: 1990-08-21
Filing date: 1990-08-21
Publication date: 1999-03-16
Anticipated expiration: 2010-08-21
Also published as: CA2023735A1

Abstract

This invention relates to novel compositions and a novel process for removing toxic resin acids and their derivatives from water and waste water effluent. In one specific aspect, the invention pertains to novel compositions and a novel process for removing toxic resin acids from effluent of pulp and paper mills. A composition for treating effluent comprising: (a) a water soluble nonionic polyalkylene ether containing lower alkyl groups in the alkyl chain and having a molecular weight exceeding 50,000; and (b) an ionic water-soluble polymer having a molecular weight exceeding about 10,000.

Description

~2 ~3~35 ., TOXIC RESIN ACIDS AND THEIR DERIVATIVES FROM EFFLUENT

FIELD OF THE l~V~ lON

This invention relates to novel compositions and a novel process for removing toxic resin acids and deriva-tives from water and waste water effluent. In one specific aspect, the invention pertains to novel compositions and a novel process for removing toxic resin acids from effluent of pulp and paper mills.

BAC~GROUND OF THE lNv~ lON

15 Toxic acids and harmful substances are contained in effluent of many industries, for example, industrial manufacturing plants, municipal sewage treatment plants, petroleum, gas and metal producing processes. Anionic organics and phosphates are contained in municipal efflu-ents. To prevent or curtail damage to what has been discovered to be a delicate environment, considerable research and development activity has taken place with the objective of discovering novel compositions and processes for reducing or eliminating the toxic components of indus-trial and municipal effluent streams.

Norwegian Patent No. 8,704,840, June 20, 1983,entitled "Retention or Cleaning Process for Waste Water and Cellulose Fibre Suspensions", discloses the use of poly-ethyleneoxide (PEO) with phenol formaldehyde resin (PF) andcationic starch as a retention aid and/or clarifier floccu-lant.

Canadian Patent No. 1, 150, 913, August 2, 1983, entitled "Separation of Unbleached Sulphate Fibres from Aqueous Fibre Suspension by Adding High Molecular Weight Polyalkylene Oxide as Flocculant", discloses the use of polyethyleneoxide (PEO) as a selective flocculant for 2 ~ 7 3 5 unbleached Kraft fibre in mixed secondary furnishes to upgrade paperboard.

Canadian Patent No. 1,004,782, Hecktor et al., granted February 1, 1977, disclosed a process for separat-ing solid and dissolved materials from waste water and in particular a process for purifying waste water from indus-tries dealing with "lignocellulose" fibres, for example, the paper and board industries. Hecktor et al. purify waste water container cont~m;n~nts by treating the water with a sufficient amount of a phenolformaldehyde resin (PF) to form flocs which contain the cont~m;n~nts and resin.
This is done in the presence of a water soluble non-ionic polyalkylene ether containing lower alkyl groups in the alkyl chain and having a molecular weight exceeding 50,000.
The flocs are then separated. In a specific embodiment, polyethylene oxide of a molecular weight of about 300,000 having a solid content of 0.1~ by weight is used.

U.S. Patent No. 3,141,816 also discloses a method of treating white water by using ethylene oxide polymers as flocculants.

Because of the increasing awareness of damage and potential damage to the environment by toxic resin acid containing effluent, governmental regulatory bodies have been passing regulations which place maximum permissible levels on toxicity emitted in pulp and paper effluent streams. If such toxin levels are exceeded, the pulp and paper mills suffer economic hardship because the production rates must be reduced to stay within the limits.

SUMMARY OF THE lNv~L.llON

Effective resin acid removal is achieved by treatment of the resin acid containing effluent using a coagulant such as a multivalent metal ion, (eg. aluminum), 2~ .3 ~P

alone or in conjunction with another flocculant or by treatment of the effluent with a natural, or chemically modified organic colloid, such as cationized guar gum, lignin, or lignosulfonate. This treatment is then followed by flocculation and removal of the flocs by a liquid-solid separation technique. Dissolved air flotation, decantation and filtration are acceptable techniques.

The invention is directed to a composition for treating effluent comprising: (a) a water soluble non-ionic polyalkylene ether containing lower alkyl groups in the alkyl chain and having a molecular weight exceeding 50,000; and (b) a non-phenolic ionic water-soluble polymer having a molecular weight exceeding about 10,000. The composition may include guar gum.

The polyalkylene ether can comprise between about 10% to 100% by weight of the composition, and the ionic water-soluble polymer can comprise between about 0% to about 90% by weight of the composition. The polyalkylene ether can be polyethylene oxide having a molecular weight of between about 100,00 to about 10,000,000. The ionic water-soluble polymer can have a molecular weight of between about 10,000, and 30,000,000.
The invention is also directed to a process for purifying waste water containing contaminants which com-prises treating the water with a sufficient amount of a water-soluble non-ionic polyalkylene ether containing lower alkyl groups in the alkyl chain and an ionic water-soluble polymer.

In the process, the polyalkylene ether and the ionic polymer can be added to the effluent at a concentra-tion in a range of usually less than 10 parts per millionof the waste water effluent (the upper dosage limit being established by resin acid concentration, efficacy and econ-- _ 4 _ ~ n ~ ~ 7 ~ 5 omics). The effluent can also be treated with a composi-tion containing polyaluminum chloride. The polyaluminum chloride can be mixed with polyepiamine ( a copolymer of epichlorohydrin, dimethyl amine and occasionally some other organic amine). The composition can include polydiallyd-imethylammonium chloride (polyDADMAC).

The invention is also directed to a composition for treating effluent comprising:
Polyethylene oxide - 10-99.9 Ionic Polyacrylamide - 0.1-90 adding up to lO0~ of the formulation.

Alternatively, the composition for treating effluent can comprise:
Polyethylene oxide - 5-99.9 Ionic Polyacrylamide - 0.1-90 Guar based polymer - 0-90 adding up to lO0~ of the formulation.
A further composition for treating effluent comprises:
Com~onent A
Alum (Aluminum sulphate) - 0-50 Polyaluminum chloride (PAC) - 5-99.9 Polyepiamine (100,000 mol. wt.) - 0-50 Polyepiamine (300,000 mol. wt.) - 0-50 adding up to lO0~; and Component B
Polyethylene oxide - 5-99.9 Cationic Polyacrylamide - 0.1-90 Guar based polymer - 0-90 adding up to lO0~ of the formulation.

~ ~ 2 è~ 7 ~P ~
~_ - 5 DETAILED DESCRIPTION OF SPECIFIC
EMBODIMENT8 OF THE lNv~.llON

We have invented a novel process for removing or greatly reducing toxic resin acids and/or their derivatives from water and waste water, particularly in pulp and paper mills effluent and woodwaste leachate effluent. Effluent toxicity is a waste water parameter that is subject to strict government regulation. Offending sources are shut down or curtailed.

In our process, waste waters containing up to several hundred parts per million of resin acids, and their derivatives, can be treated to remove such resin acids, using a coagulant such as alum (aluminum sulphate), poly-aluminum chloride, ferric chloride, and/or organic coagu-lants such as polydiallyldimethylammonium chloride, and polyepiamine.

Such coagulants may be used alone or in blended combinations. The treatment can include coagulant addition alone or can be in conjunction with a natural, or chemical-ly modified organic colloid, such as guar or lignin. The chemically modified organic colloid can also be used alone.
This treatment is then followed by the addition of a flocculant blend consisting of polyethylene oxide with or without an ionic water-soluble polymer. This overall treatment, after allowing a floc to form which is separated from the liquid phase, reduces the level of resin acid and their derivatives in such aqueous systems.

Our treatment is very flexible and versatile because it can be used with or without further biological treatment of effluent (for example, aerobic or anaerobic), and with and without other traditional waste treatments such as primary sedimentation and filtration.

~ ~373S
~_ - 6 -Two ComPonent Composition We have conducted experimental research into a group of substances which have been found unexpectedly to be highly useful in removing toxic resin acids from efflu-ent streams. In particular, the inventors have discovered that the following specific two component composition is uniquely effective in removing resin acids from effluent:

Polyethyleneoxide - 10-99.9 Ionic Polyacrylamide - 0.1-90 adding up to lOO~ of the formulation.

We have discovered that if this combination is added at a concentration of usually less than 10 parts per million to an effluent containing toxic resin acids, toxic resin acid levels in the effluent are reduced.

Three Component ComDosition We have also discovered that the following three component composition is effective in removing toxic resin acids from effluent:
Polyethyleneoxide - 5-99.9 Cationic Polyacrylamide - 0.1-90 Guar based polymer - 0-90 adding up to lOO~ of the formulation The polyethyleneoxide, the polyacrylamide and the guar based polymer are mixed together.

- 7 - ~ ~ ~ 3 7 3 ~

Multi-ComPonent comPosition In addition to the foregoing, we have also discovered unexpectedly that the following two component composition is highly effective in removing or substan-tially neutralizing the toxic resin acids in effluent:

ComPonent A
Alum (aluminum sulphate) - 0-50%
Polyaluminum chloride (PAC) - 5-99.9%
Polyepiamine - (100,000 mol. wt.) - 0-50 Polyepiamine - (300,000 mol. wt.) - 0-50%
adding up to 100% of the formulation.

comPonent B
Polyethyleneoxide - 5-99.9%
Cationic Polyacrylamide - 0.1-90%
Guar based polymer - 0-90%
adding up to 100% of the formulation.
PAC, polyepiamine 100,000 mol. wt. and polyepiamine 300,000 mol. wt. are all available from Diachem Industries Ltd. Polyepiamine 100,000 mol. wt. is available under the trade-name DIAFLOCC 3490TM.
Polyepiamine 300,000 mol. wt. is available under the trade-name DIAFLOCC 359 oTM .

The foregoing two-component formulation, we have discovered, is effective in neutralizing or removing toxic resin acids in effluent streams if about 50 or less parts per million of component A is added to the effluent, fol-lowed by usually less than 10 parts per million of compo-nent B.

Resin acid Separation For the following examples, Component A was a mixture of 10% liquid alum, 80% PAC and 10% polyepiamine.
Component B was a mixture of 50% polyethylene oxide, 40%
cationic polyacrylamide and 10% cationic guar.

Example #1 A 1 litre sample of waste water in the form of diluted black liquor taken from the spill lagoon of a Kraft pulpmill at pH 10.9 containing 14.4ppm of resin acids was placed in a 1 litre beaker. During agitation at lOOrpm using a paddle stirrer, 4 ml of a 1% w/w solids solution of lignosulfonate was added. After 30 seconds of agitation, 3 ml of a .029% solution of cationic polyacrylamide based polymer, and 3 ml of a 0.1% solution of a 7 million molecu-lar weight polyethylene oxide (PE0) were added to the dilute black liquor. Agitation was continued for 75 seconds after which the agglomerated flocs were allowed to settle. After 30 minutes of settling, 500 ml of treated dilute black liquor was decanted from the beaker and analysed for resin acid content. The resin acid concentra-tion after treatment and settling was 9.1ppm, a 37% removal rate.

Example #2 The same procedure and test liquid as in Example #1 was repeated except for the omission of cationic poly-acrylamide from the treatment. Resin acid concentration after treatment and settling was 11.5ppm or a 20% removal rate. This test demonstrated that treatment is much more effective when cationic acrylamide is included.

~ 9 2 ~

Example #3 The same procedure and test liquid as in Example #2 was repeated, however 1 ml of a 1% solution of Component A was added 15 seconds after the addition of the ligno-sulfonate and 15 seconds prior to the addition of the polyethylene oxide. Resin acid concentration after treat-ment and settling was 10.5%, a 27% removal rate. This example showed the high utility of a mixture of PAC, alum and poly epiamine.

ExamPle #4 The same procedure, but a different test liquid than used in Example #1, was repeated with the only treat-ment being addition of 5 mls of a 0.1% solution of Compo-nent B, followed by 75 seconds of agitation. The test liquid was obtained from the same location as Example 1, but at a time when resin acid concentration was 17.6ppm.
Resin acid concentration after treatment and settling was 13.5ppm, a 23% removal rate. This example demonstrated that reasonable removal can be achieved using one blended product of the invention.

ExamPle #S

The same procedure and test liquid as in Example #4 was used but treatment consisted of the non-polyethylene oxide components of Component B. Resin acid concentration after treatment and settling was 16.3ppm, a 7% removal rate, showing the necessity of including PEO in the treatment to be effective.

Example #6 One litre samples of waste water of combined effluent streams from all sections of a Kraft pulp mill having a pH of 6.5 were treated using the same procedure, but four different chemical treatments than in Example #1.
The resin acid concentration of the waste water was 7.8ppm.
Results of treatments 6A-6D are listed in Table 1 below.

Treatment A

4 ml of a 1% solution of lignosulfonate was followed by 2 ml of a 1~ solution of Component A
which was followed by 2 ml of a 0.1% w/w solution of PE0.

Treatment B
The same treatment as 6A was used except that 3 ml of a .029~ solution of a cationic polyacyl-amide was added after component A and prior to PE0 addition.

Treatment C
The same treatment as 6B, but omitting the PE0.
Treatment D
The same treatment as 6B, but omitting the ligno-sulfonate.

Table 1 Treatment Resin acid conc. after treatment % Ren~l 6A 4.3 46 6B 3.8 51 6C 6.7 14 6D 3.2 59 Example 6 Discussion Treatment 6C illustrates the need to include PE0 in the treatment, while treatment 6D shows that lignosulfates are not always required.

7 ~
jl~ S~ PJ~ 7 oJ

Example 7 The same test solution and procedure as in Example #6 was used. However, chemical treatment consisted of 4 ml of a 1% solution of Component A followed by 15 seconds of agitation, followed by 3 ml of a .035% solution of a cationic polyacrylamide and 3 ml of a 0.1% solution of PEO. After settling and decantation the resin acid concen-tration was 2.4ppm, a removal rate of 69%.
Ionic Water-Soluble Polymer By the term ionic water-soluble polymers in this disclosure, we mean to include any non-phenolic water soluble polymer which carries or is capable of carrying an ionic charge when dissolved in water, whether or not that charge-carrying capacity is dependent upon pH. Such polymers include condensation polymers as well as polymers derived from vinyl monomers. As an example of successful use of these ionic polymers, the polymers obtained from the condensation reaction of epichlorohydrin and ethylene-diamine and/or dimethylamine may be successfully used.

Vinyl polymers having water solubility and ionic characteristics, as described above, include modified polyacrylamides, modification being made, for example, by the typical Mannich reaction products or the quaternized Mannich reaction products known to the artesan, or the vinylic polymers, copolymers and terpolymers which use as vinyl monomers those monomers containing functional groups which have ionic character. As an example, but not limit-ing to the scope of this invention, we include in these vinyl monomers, monomers such as DMAEM, DMAEM QUAT, DACHA
HCl, DADMAC, DMAEA, DMAEA QUAT, MAPTAC, AMPIQ, DEAEA, DEAEM, and ALA (see Table 2 below for definitions), the quaternized compounds containing these monomers, acrylic acid or its salts, vinyl carboxylic acids or their salts, acrylamide monomer, and the like.

Table 2 Monomer Abbreviation-Q

DMAEM = Dimethylaminoethylmethacrylate and/or its acid salts.

DMAEM QUAT = Dimethylaminoethylmethacrylate quaternized with dimethylsulfate, methylchloride or methyl Bromide DACHA HCl = Diallylcyclohexylamine Hydro-chloride DADMAC = Diallydimethyl ammonium chloride DMAEA QUAT = Dimethyl amino ethyl acrylate quaternized with Dimethyl sulfate, methyl chloride or methyl Bromide MAPTAC = Methacrylamidopropyl trimethyl ammonium chloride AMPIQ = l-acrylamido-4 methyl piperazine (quaternized with MeC1, MeBr or Dimethyl sulfate) DEAEA = Diethyl aminoethyl acrylate and/or its salts.

DEAEM = Diethyl aminoethyl methacrylate and/or its salts ALA = Allyl amine To be effective, these polymers, be they conden-sation polymers or vinyl polymers must have a molecular weight of at least 10,000 and may have molecular weights exceeding l,OOO,oO0.

Polyacrylamide Based Polymer By the term "poly acrylamide based polymer" we mean to include any water soluble polymer which contains acrylamide. Numerous representative comonomers are listed under "Ionic Water Soluble Polymers".

Resin Acid By the term Resin Acid, we mean to include organic acids extracted from wood during milling or pulping processes. Examples of resin acids include Pimaric, Sandaracopimaric, Isopimaric, Levopimaric, Dehydroabietic, Abietic, and Neoabietic acids.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.

Claims

1. A composition for treating resin acid containing effluent comprising:
(a) a water soluble non-ionic polyalkylene ether containing lower alkyl groups in the alkyl chain and having a molecular weight exceeding 50,000; and (b) a non-phenolic cationic water soluble polymer having a molecular weight exceeding about 10,000.

2. A composition for treating resin acid containing effluent comprising:
(a) a water soluble non-ionic polyalkylene ether containing lower alkyl groups in the alkyl chain and having a molecular weight exceeding 50,000; and (b) a substance selected from the group consisting of, a non-phenolic cationic water soluble polymer having a molecular weight exceeding about 10,000, chemically modified guar gum, polyhydroxy aluminum chloride (PAC), alum, multi-valent metal ion, cationic starch, non-ionic or cationic cellulose derivative, polyepiamine, and polydiallydimethyl ammonium chloride.

3. A composition for treating resin acid containing effluent comprising:
(a) a water soluble non-ionic polyalkylene ether containing lower alkyl groups in the alkyl chain and having a molecular weight exceeding 50,000; and (b) one or more of the following substances, a non-phenolic cationic water soluble polymer having a molecular weight exceeding about 10,000, lignosulfonic acid and salts thereof, lignin and chemical modification thereof, organic sulfonate, and non-ionic or cationic cellulose derivative.

4. A composition according to claim 1 wherein the polyalkylene ether comprises between about 10% to 99.9% by weight of the composition, and the cationic water soluble polymer comprises between about 0.1% to about 90% by weight of the composition, adding up to 100% of the formulation.

5. A composition according to claim 1 wherein the polyalkylene ether is polyethylene oxide having a molecular weight of between about 100,000 to about 10,000,000.

6. A composition according to claim 1 wherein the cationic water soluble polymer is polyacrylamide based and has a molecular weight of between abut 100,000 and 30,000,000.

7. A composition for treating effluent which comprises:
(a) polyethylene oxide - about 10 - 99.9% by weight;
and (b) cationic polyacrylamide - about 0.1 - 90% by weight;
the total adding up to 100%.

8. A composition for treating effluent which comprises:
(a) polyethylene oxide - about 10 - 99.9% by weight;
(b) cationic polyacrylamide - about 0.1 - 90% by weight; and (c) an effective amount of guar based polymer;
the total adding up to 100%.

9. A process for purifying waste water containing contaminants which comprises treating the water with a sufficient amount of water soluble non-ionic polyalkylene ether containing lower alkyl groups in the alkyl chain and a cationic water soluble polymer to reduce the contaminants to an acceptable level.

10. A process according to claim 9 wherein the polyalkylene ether and the cationic water soluble polymer are added to the effluent at a concentration in a range of less than 10 parts per million.

11. A process according to claim 9 wherein the effluent is also treated with a composition containing polyaluminum chloride.

12. A process according to claim 11 wherein the polyaluminum chloride is mixed with polyepiamine.

13. A processs according to claim 11 wherein the polyaluminum chloride is mixed with polydiallyldimethylammoniumchloride.

14. A composition for removing or substantially neutralizing toxic resin acids in effluent comprising:
(a) 10% liquid alum by weight;
(b) 80% polyaluminum chloride by weight; and (c) 10% polyepiamine by weight.

15. A composition for removing or substantially neutralizing toxic resin acids in effluent comprising:
(a) 50% polyethylene oxide by weight;
(b) 40% cationic polyacrylamide by weight; and (c) 10% cationic guar based polymer.

16. A composition for removing or substantially neutralizing toxic resin acids in effluent comprising:
(a) 5 - 20% liquid alum by weight;
(b) 60 - 90% polyaluminum chloride by weight; and (c) 5 - 20% polyepiamine by weight.

17. A composition for removing or substantially neutralizing toxic resin acids in effluent comprising:
(a) 20 - 70% polyethylene oxide by weight;
(b) 20 - 60% cationic polyacrylamide by weight; and (c) 1 - 20% cationic guar based polymer

18. A process for removing toxic resin acids from waste water effluent comprising the following steps:
(a) first adding to the waste water a composition comprising liquid alum, polyaluminum chloride, and polyepiamine;

(b) agitating the waste water;
(c) next, mixing polyethylene oxide into the waste water; and (d) finally, allowing the toxic resin acids to settle from the waste water effluent.

19. A process according to claim 18 further comprising the step of adding cationic polyacrylamide to the waste water effluent with the polyethylene oxide.

20. A process according to claim 19 wherein the cationic polyacrylamide and the polyethylene oxide are mixed together before being added to the waste water effluent.

21. A process according to claim 19 further comprising the step of first adding lignosulfonate to the waste water before any of the other substances are added.