SE467667B - PROCEDURES CONCERN REGULATION OF PRODUCTION CONTROLLING MICROBIOLOGICAL PROVISIONS ON PAPER MANUFACTURING EQUIPMENT - Google Patents

Description

467 667 10 15 20 25 30 35 35 the composition of any recycled material added to the process as well as the additives used in preparing the suspension. Thus, a variety of dissolved or suspended materials can be introduced into the manufacturing process, including both ear and materials, which are pitch technical materials, e.g. salts and clays, organic in nature, such as resins or from wood as well as inks, latexes and binders from recycled paper products. A build-up of deposits containing organic and / or organic materials on felt and other sheet-forming equipment during the manufacturing process is a well-known troublesome problem in connection with efficient papermaking.

Another particularly troublesome deposit is the slimy gelatinous material produced by certain bacteria, which occur naturally in the papermaking system. (This material is hereinafter referred to as "mucus"). Since the conditions of a paper machine system are normally very favorable for the growth and reproduction of bacteria, the problems of accumulation of slime deposits on paper machine parts are often answered, and if they are not eliminated, they will lead to significant production disruptions in the papermaking process.

A typical problem caused by mucus deposits occurs when large lumps of accumulated mucus fall from the position where they were formed on the sheet of paper, thus giving rise to a sheet defect and / or a sheet breakage.

Methods for quickly and efficiently removing slime deposits from the paper machine equipment are of great importance to the industry. The paper machines could be closed for cleaning, but such interruptions for cleaning purposes are undesirable due to the resulting production losses. So-called on-line treatment is thus strongly preferred, where such can be performed in an efficient manner.

The most common and most successful way to remove slime from paper machine equipment has been to treat the aqueous fiber suspension with various types of biocides.

Examples of such biocides are methylene bis-thiocyanate, S-chloro-2-methyl-4-isothiazlin-3-one and 2-methyl-4-isothiazolin-3-one.

However, chemicals of this type are often very unpleasant to handle and are often regarded from an environmental point of view as well as health and safety point of view as unpleasant or reprehensible. For these reasons 10 15 20 25 30 35 467 ee7 ° there are strong forces in industry to, wherever possible, avoid the use of biocides in the papermaking process.

Another way of trying to solve the problem of mucus control has been to combine the bicidal treatment of the fiber suspension with the addition of anionic dispersants. However, the success of this solution has been very limited, especially in paper systems operating with a high degree of closed backwater system. Yet another way to try to achieve mucus regulation has been to treat the fiber suspension with enzymes. However, the commercial success of this method has also been very limited.

Against this background, it is easy to see that a method that would enable efficient regulation of slime deposits on paper machines, without the disadvantages associated with biocides, would be a significant step forward towards a more environmentally acceptable papermaking process.

It has now surprisingly been found that productivity problems caused by the deposition of organic material derived from microbiological activities can be effectively controlled or regulated without any use of toxic biocides or using reduced amounts of such biocides, namely through the use of certain polymers. or surfactants and without incorporating the substances in question into the pulp. The polymers or surfactants in question are previously known per se, but as far as we know, they have never been used or proposed for use in the manner claimed in the present invention. In this regard and in connection with the above-mentioned prior art, reference is made to the following prior art: CA 1 150 914 EP 0 058 621, US 3,582,461 and US 4,190 491, to resin control in connection with papermaking; 396 and US 4,451,376, which are known per se to inhibit the growth of and GB 2 185 895, potassium which are useful in accordance with the present invention all of which relate to GB 1 486 both of which relate to chemical substances which describes a group of chemical microorganisms; but which are not disclosed for such use therein. Thus, according to the present invention, it has surprisingly been found that certain cationic polymers or cationic surfactants or mixtures thereof can be used effectively, without any toxic biocides or in combination with such biocides in greatly reduced amounts, to control or regulate deposition in connection with papermaking of production-disrupting microbiological deposits, whereby said cationic polymers or surfactants are used in a new way.

An object of the invention is therefore to provide an improved papermaking process, in which deposition of organic material of the above-mentioned type is controlled, i.e. prevented or inhibited completely or at least to a very large extent, if the deposition in question has not already been formed, or is reduced. or completely or extensively dispersed, if the deposit has already formed. The invention is of particular interest in connection with the regulation of mucus caused by mucus-forming microorganisms.

Another object of the invention is to provide a new process, by means of which the use of toxic biocides is eliminated or greatly reduced, ie to provide a disposal control process for paper mills, which process is acceptable from an environmental point of view. Yet another object of the invention is to provide a novel process by which the incorporation of chemicals into the pulp is avoided or reduced.

Another object of the invention is to provide a process by which substantially reduced concentrations of chemicals are utilized to control or control the above-mentioned deposition problems. Yet another object of the invention is to provide a method by which the productivity and product quality associated with papermaking are improved.

A further object of the invention is to provide a high quality paper manufactured by the method according to the invention.

These and other objects and advantages of the present invention will become more apparent from the following more detailed description of the invention. 10 15 20 25 30 35 467 667 E! J. I I I .V. E..

According to the invention, the above-mentioned objects and other objects are achieved by providing a method for regulating production-disrupting microbiological deposits on papermaking equipment, wherein the method is characterized in that at one place or some surface on said papermaking equipment, which place or surface is sensitive to the build-up of such microbiological deposits, applies a scale-regulating amount of a scale-regulating substance selected from the group consisting of cationic polymers and cationic surfactants, which comprises mixtures thereof.

As mentioned above, the term "regulation" should. "control" or the like is given a broad meaning in connection with the invention. In other words, according to the invention, it has surprisingly been found that the cationic polymer or the cationic surfactant or a mixture thereof can be used both to prevent or inhibit the formation of deposits and to dissolve or disperse deposits which have already formed.

As to the meaning of the expression "any place or surface of the papermaking equipment which is sensitive to the build-up of such deposits" or the like, it may be added that the general meaning thereof is that the cationic polymer or surfactant is not incorporated in the pulp or paper but is applied to any strategic part or position of the papermaking equipment.Thus, a person skilled in the art knows from experience which place or surface shows the greatest tendency to form deposits, i.e. where the cationic polymer or the cationic the surfactant should primarily be applied to obtain the best possible results.Of course, this also means that the polymer or the surfactant can be applied to more than one such site or surface, if necessary or appropriate.

The invention is generally applicable to any water-soluble cationic polymer or water-soluble surfactant of the type indicated above, which primarily means that a water-based solution of this polymer or this surfactant is used. This in turn means that a particularly preferred method of applying the cationic polymer or cationic surfactant to said site or surface is by means of a spray or spray operation, since this is generally is a simple operation and since such an operation has been found to be very effective in connection with the invention. In other words, it has surprisingly been found that very low concentrations of the polymer can be used in this way to obtain excellent results.

The method according to the invention is generally applicable to the regulation of any deposit caused by microorganisms, but it has been found to be particularly interesting for the regulation of deposits caused by bacteria, e.g. sludge caused by mucus-forming bacteria.

Since the main feature of the invention is the application of the cationic polymer or cationic surfactant directly to the site or surface to be treated, said polymer or surfactant being used in surprisingly low concentrations, the exact nature of the polymer or surfactant used, is not the important feature of the invention, provided that said polymer or surfactant is of the cationic type. Thus, a variety of different polymers and surfactants can be used within the scope of the invention, ie also based on previously known microbiocidal activities. However, a number of especially preferred polymers and surfactants will be discussed below.

Typically, a water-soluble polymer or a water-soluble surfactant is used.

Thus, according to a preferred embodiment of the process, a cationic polymer is used, which has a molecular weight in the range 1,000 - 5,000,000, for example between about 10,000 and about 300,000.

A preferred embodiment within these ranges is from about 20,000 to 300,000, especially from about 20,000 to 50,000. Another preferred range is from about 10,000 to 50,000.

As for the cationic surfactant, a preferred range for its molecular weight is between about 200 and 600.

According to another preferred embodiment of the invention, an aqueous solution of the pelymer or surfactant is used, which solution is substantially free of anionic macromolecules.

The charge density of the compounds used according to the invention should be in a range of from about 0.5 milliequivalents / gram to 20 milliequivalents / gram. A preferred embodiment in this area is about 1-10 milliequivalents / gram, in particular 2-8 milliequivalents / gram.

A preferred group of cationic polymers of the invention includes dicyandiamide-formaldehyde condensation polymers.

Polymers of this type are described in many patents.

US 3,582,461, US 2,829,126, GB 1,193,294, DE 917,392, FR 1,484,381, DE 2,017,114, JP 75 111,864, JP 73 16,067, DE OS 2,515,175, CH application 9,527 / 72, DE OS 2 451 698, DE 1 126 276, DE OS 2 403 443, FR 1 414 407 and DE 2 321 627 represent some examples of such.

Another preferred group of cationic polymers for use according to the invention are the polymers formed by reaction between epihalohydrins and various amines. The most preferred epihalohydrin in this regard is epichlorohydrin, and examples of suitable amines include dimethylamine, diethylamine, methylethylamine, ethylenediamine, triethanolamine and a polyalkylene polyamine. Examples of such include the polymers obtained by reaction between a polyalkylene polyamine and epichlorohydrin as well as the polymers obtained by reaction between epichlorohydrin, dimethylamine and either ethylenediamine or a polyalkylene polyamine. A typical amine that can be used is fi, N, N ', N'-tetramethylethylenediamine as well as ethylenediamine used in conjunction with dimethylamine and triethanolamine. Polymers of this type include those polymers having the following general formula:. Û "W fl z fifl z CH: | + I Hæ fl gül-lz _- I-C fl g-CH-C fl z I., _ Cl-Ig-C fl- CH; --_- IH-CH2 u | l CPI Hæ fl güig Cl 'OH C83 Gl A 2 where A is a number in the range 0-500.

Preferred cationic polymers of the present invention also include those obtained by reacting dimethylamine, diethylamine or methylethylamine, preferably either dimethylamine or diethylamine, with an epihalohydrin, epichlorohydrin. Polymers of this type are described in U.S. Patent 3,738 where the contents of these baths are preferably 945 and Canadian Patent 1,096,070, 467,667 and 15 are hereby incorporated into the present text. Such polymers are commercially available as Agefloc A50, Agefloc A-SOHV and Agefloc B-50 from CPS Chemical Company, Inc., of New Jersey, USA. These three products are stated to contain as their active ingredients about S0% by weight of polymers with molecular weights of about 75,000 to 80,000, about 200,000 to 250,000 and about 20,000 to 30,000, respectively. Another commercially available product of this type Magnifloc 573C, marketed by the American Cyanamide Company in New Jersey, USA, is believed to contain as its active ingredient about 50% by weight of a polymer having a molecular weight of from about 20,000 to 30,000.

Another preferred group of cationic polymers for use in the invention comprises polymers derived from ethylenically unsaturated monomers containing a quaternary ammonium group. Such polymers may include homo- and copolymers of vinyl compounds, such as vinylpyridine and vinylimidazole, which may be quaternized with e.g. a C 1 -C 15 alkyl halide, a benzyl halide, especially a chloride, or dimethyl or diethyl sulfate or vinyl benzyl chloride, which may be quaternized with e.g. a tertiary amine of formula NRIRQR 3, wherein R 1, R 2 and R 3 are each and independently lower alkyl, preferably having 1-4 carbon atoms, with the proviso that one of these groups R 1, R 2 and R 3 may be C 1 -C 13 alkyl; allyl compounds, such as diallyldimethylammonium chloride; or acrylic derivatives, such as dialkylaminomethyl (meth) acrylamide, which may be quaternized with a C 1 -C 18 alkyl halide, a benzyl halide or dimethyl or diethyl sulphate, a methacrylamidopropyl tri (C 1 -C 4 alkyl, especially methyl) ammonium salt or a (meth) acryloyloxyethyl tri- (C 1 -C 4 alkyl, especially methyl) ammonium salt, said salt being a halide, especially a chloride, methosulfate, ethosulfate or 1 / n of an n-valent anion.

In this context, it should also be added that in the description and claims the term "lower alkyl" means an alkyl group containing 1-6 carbon atoms, unless otherwise stated.

In the above-mentioned case of copolymers, the monomers can be copolymerized e.g. with a (meth) acrylic derivative, such as an acrylamide, an acrylate or methacrylate C 1 -C 3 alkyl ether or acrylonitrile, or an alkyl vinyl ether, vinylpyrrolidone or vinyl acetate. Typical such polymers contain from 10 to 100 mole percent repeating units of the formula: 'J 10 15 20 25 30 35 h 4e7vee7 | la * M - = - | | coø (cu2); r-- u _ x- Ice and 0-90 mol% repeating units of the formula: h I __ cu2__ 1: - In m: wherein R 1 represents hydrogen or lower alkyl, preferably alkyl of 1-4 carbon atoms, R 2 represents a long chain alkyl group, typically having from 8 to 18 carbon atoms, R 3, R 4 and R 5 each and independently represent hydrogen or lower alkyl, while X represents an anion, typically a halide ion, a metoeulfate ion, an ethosulfate ion, or a 1 / n of an n-valent anion.

Other quaternary ammonium polymers derived from an unsaturated monomer include homo- and copolymers of diallyldimethylammonium chloride, which contain repeating units of the formula: .___ c fl __. CH 2 CH 2 -C 2 Z 2 CH 2 CH 2. + / Cl- .__ J "ca; cH 3 where Z represents monomeric units, such as for example a (meth) acrylic derivative, such as an acrylamide, an acrylate or methacrylic lat-C1-C18-alkyl ester or acrylonitrile, or an alkyl vinyl ether, vinylpyrrolidone or vinyl acetate, m is in the range 5-100% and n is in the range 0-95% 467 667 In this regard, it should be noted that this polymer should is considered "essentially linear", because despite the presence of cyclic groups, these groups are connected along a linear chain and there is no cross-linking. Other polymers which may be used and which are derived from unsaturated monomers include those of the formula: + + ï mnls _ run-I. z _ 'I m X' X '| where Z and Z ', which may be the same or different, are -CH 2 CH = CHCH 2 - or CH 2 -CHOHCH 2 -, Y and Y', which may be the same or different, are either X or -NR'R ", X is a halogen having an atomic weight greater than 30, n is an integer from 2 to 20, and R 'and R "(i) may be the same or different alkyl groups having from 1 to 18 carbon atoms, optionally substituted with 1 to 2 hydroxyl groups; or (ii) when viewed together with N, represents a saturated or unsaturated ring having from S to 7 atoms; or (iii) when viewed together with N and an oxygen atom, represents the N-morpholino group; especially poly (dimethylbutenyl) ammonium chloride bis- (triethanol ammonium chloride).

Another class of polymers which can be used and which are derived from ethylenically unsaturated monomers include polybutadienes which have reacted with a lower alkylamine and in which some of the resulting dialkylamino groups are quaternized. In general, therefore, the polymer contains repeating units of the formula: I) -fl i fl g-UU- b) -fl ïllg-OU- t) -fl ïilz-FÜ- OM I) -fülrgl- O! bl; Fl; 2 I a: bl: C fl z z | of 4 h; X 'H2 in the molar ratios a: b: c: d respectively, where R represents a lower alkyl radical, typically a methyl or ethyl radical. It may be added that the lower alkyl radicals need not be the same at all. Typical quaternizing agents include methyl chloride, dimethyl sulfate and diethyl sulfate. Varying ratios a: b: c: d can be used, the amine amounts (b + c) usually being from 10 to v) 90% and (a + d> being from 90 to 10%. polymers can be obtained by reacting polybutadiene with carbon monoxide and hydrogen in the presence of a suitable lower alkylamine.

Other cationic polymers, which exhibit the ability to interact with anionic macromolecules and / or mucous materials in papermaking compositions, may also be used within the scope of the present invention. These may include cationic tannin derivatives, such as those obtained via a Hannich-type reaction of tannin (a condensed polyphenolic core) with formaldehyde and one formed as a salt, acetate, formate, hydrochloride, amine, e.g. or quaternized, as well as polyamine polymers which have been crosslinked, such as polyamidamine / polystylene polyamine copolymers crosslinked with e.g. spichlorohydrin. Yet another suitable type of polymer is that obtained by reacting a polyamidoamine with epihalohydrin. Such crosslinked polyamidoamines are described in U.S. Patents 3,250,664, 3,893,885, 3,642,572 and 4,250,299, incorporated herein by reference. According to a preferred embodiment of the invention, the cationic surfactant has the general formula "* - _, .- f I * Iz ¶ | wherein each group R is independently selected from the group consisting of hydrogen, alkyl groups having between about 1 and 22 carbon atoms, aryl groups and aralkyl groups, at least one of these R groups being an alkyl group having at least about 8 carbon atoms, and preferably an n-alkyl group having between about 12 and 16 carbon atoms; X 'is an anion, preferably a halide ion, rid, or 1 / n of an n-valent anion Mixtures of these compounds can also be used as the surfactant of the present invention.

Preferably, two of the R groups of the surfactant are selected from the group consisting of methyl and ethyl, most preferably methyl.

Preferably, an R group is also selected from the aralkyl groups Ph-CH2- and Ph-CH2-CH2-, where Ph is phenyl. The most preferred aralkyl group is benzyl.

Thus, particularly useful surfactants include alkyl dimethylbenzylammonium chlorides having alkyl groups of between about 12 and 16 carbon atoms. A commercially available product of this type comprises a mixture of alkyldimethylbenzylammonium chlorides, wherein about 50% of the surfactant has a C 12 H 29 -n-alkyl group, about 40% of the surfactant has a C 12 H 25 -N-alkyl group, and about 10% of the surfactant has a C15H33-n-alkyl group. This product is known per se for microbiocidal efficacy.

As mentioned above, it has been found that when the cationic polymers and / or cationic surfactants of the present invention are applied directly, preferably by spraying them, on paper machine parts in low concentrations, mucus and other microbiological deposits on said parts or excipients. armament is significantly reduced or eliminated. More specifically, it has been found that usually such a low concentration of the polymer or surfactant as from about 0.1 million parts (ppm) of the dilution water gives a deposition-reducing effect.

Preferably, this amount is from about 5 million parts of dilution water when continuous treatment is used, while preferably from about 50 million parts of dilution water is used during the application period, when the application is intermittent. As for the upper limit, it can be easily determined by a person skilled in the art in each individual case, but in general this amount or concentration is kept at as low a level as possible to avoid unnecessary contamination of the paper therewith. A preferred upper limit is 500 million parts of dilution water. Although the mechanism of the phenomenon obtained by the present invention is not fully understood, it is believed that the cationic components of the present invention disperse the mucus in an embryonic stage, thus preventing the formation of large clumps. The recovered cationic diepergered mucus can then be easily removed from the system together with the sheet of paper. In any case, the treatment of the present invention significantly increases the tendency or tendency of the slime to pass the papermaking equipment rather than to stick to or on it.

As mentioned above, the polymer or surfactant of the present invention is applied, e.g. by a spray procedure, in aqueous solution directly on the equipment being treated. As mentioned also, the aqueous solution containing the cationic polymer and / or the cationic surfactant should be substantially free of anionic macromolecules. These anionic materials include natural materials, such as tralignins, chemical pulp products, such as sodium lignosulfonates, and synthetic materials, such as polyacrylates.

The polymers and surfactants of the present invention are typically provided in the form of liquid compositions comprising aqueous solutions of the polymer and / or the surfactant. The polymer concentrations of the compositions may vary from relatively dilute solutions having polymer concentrations suitable for continuous application up to the solubility or gelling limit of the polymer, but usually the compositions are relatively concentrated in order to provide convenient transport and handling. In addition, the liquid compositions may comprise additional materials which improve the dissolution of the polymers, whereby more concentrated compositions can be obtained. As an example of such materials, reference may be made to alkoxyethanol, such as butoxyethanol. Suitable aqueous compositions usually contain between 5 and 50% by weight of the cationic products of the present invention. It should also be added that, if desired, the compounds used according to the present invention may be added in solid form, e.g. in the form of granules.

The most appropriate treatment dose or dosage depends on such system factors as the level of contamination of the adhesive material and whether the cleaning is continuous or periodic. Liquid compositions comprising relatively high concentrations of a polymer according to the invention (eg 50%) can also be used at full strength (100% as liquid composition), e.g. by spraying the undiluted liquid composition directly on the machine parts. Particularly where continuous treatment is carried out, however, the compositions may advantageously be diluted at the treatment site with pure fresh water or any other aqueous liquid. As this is necessary for economic reasons with regard to the water, process water may be sufficient or suitable for dilution.

In general, the process according to the invention can be carried out continuously in order to continuously regulate the above-mentioned deposits. In some cases, however, a continuous treatment is not practical, and in these cases the treatment with the cationic polymers and surfactants of the present invention may be periodic. For example, aqueous solutions of the polymer or surfactant may be sprayed onto the coated surface until said surface is sufficiently clean, and spraying may then be stopped until further treatment is necessary.

The invention will now be further described by the following non-limiting examples. em xemgel A commercial double-wire type paper machine was used to make newsprint. In order to inhibit microbiological growth and the corresponding occurrence of mucus deposits, biocides are added to the backwater circulation system of this machine.

The allowance points for the biocides have been read to the wire tank and to the shower water tank. Furthermore, a dicyandiamide-formaldehyde type cationic polymer is used as a deposition control agent, and as such it is added to the fiber suspension in a position corresponding to the suction side of the Deculator pump. The complete dosing situation as well as the machine capacity status in question is shown in Table 1, No. A.

In the first experiment, the additive for ggly was moved; mgrgg from the pulp suspension to the water used for the high pressure shower system, thus enabling the diluted cationic polymer to come directly, via the high pressure spray tubes, into contact with machine parts which are sensitive to slime deposition. The actual surfaces connected to the high pressure shower system are the top and bottom wire, the forming roller, the take-up blanket and the press blankets. The effect of the new treatment on the machine is shown in Table 1, No. B.

In the second attempt, two measures were taken. First, the addition of biocide to the shower water tank was interrupted. Second, the polymer shower treatment was extended to include the low pressure shower system. Compared with the first attempt, this extension also made it possible to reach other deposition-sensitive machine parts, ie suction cups in the wire and press section and with the polymer shower treatment.

The effect of the extended polymer shower treatment and the reduced biocide additive are shown in Table 1, No. C. 15 ^ ®w «Hm> m .whonwc fl m fi mm .m <wuæuu .m.šv fi mmß mwmmmw ß Mw> swwHmEHow-w« Em fi w: m> u m > m uxswo fi nwco fl wmwcmwcox u »wE> Hom / O ^ ow fi Hm> m .wnonw fifi w fi mm .m <wumæw .m.2v mmm mQ ~ U MU fi awcm fi mo fi ml flfi hw fi cäonn fi o nm w fi uo @ @ wo @. .m <wum fi ø .m.zv www m @ Hu Lu U: o | m |: «HoNæ fl wom fi | vH> u®EN: oo: om |: fi HoNm« pom «» wH> ~ m & | N »» oHx-m > m wc fi cwoq u <U fi uo fl m A% ææsuwswwxuæuu Om -wm fi H fifi p = @ ~ @ m> H @ E> Ho @. <nwzuwßwmxuxnu øw fi onowäm fi mcH. & os H fifi u: muum> »oE> Hom.m mw fi m. x: mu: opuæ> zuw: Q m w fi uo «mN» Emm wc fi cxo w fi | ww |: EoHw: oamëämwmcma vw nwxæH fi> <w fi uo fl m. cm wmcwwznmm fl mm xcwucmuum>: uw5m m wHuo «mN -Emm wc fi cxo w« -wm -: Em ~ m: mhwëëmwwcmq QN hwxmn «> <w« uc @ m. fi m fi mesmacuw fi -m fi w> SS m v w m m æm nwE> Hom.m wm x: wu: m ~ uw> zumDQ mw «uo fi m. ~ fi ww fi ønnwëm fi v owm mm fi mnowämw vw Hmxm» fi> <w fi uo «m.H <^ w:« wowhw> -us HHo: m «> V ~ wmw \ wxU mww \ = op co fi p: EmHm:> m wwcwë H: lxswohmmummmmm wmcwwænmmz -wwc fi nwmom o fifi mummwc uw Hwm A4 Hmwo

Claims (24)

467 667 10 15 20 25 30 16 PATENT REQUIREMENTS Procedure for regulating production-disrupting microbiological deposits, e.g. slime, on papermaking equipment, characterized in that one of the following places or any of the following surfaces of the papermaking equipment: the top and bottom wire, the forming roll, the receiving blanket, the press blankets and / or suction boxes in the wire and press section, apply a deposition regulating amount of a deposition control substance, preferably at least about 0.1 millionth of the deposition control substance per part of dilution water, wherein the deposition control substance is selected from the group consisting of cationic polymers and cationic surfactants, preferably water-soluble polymers and water-soluble cationic surfactants. Process according to claim 1, characterized in that said cationic polymer or cationic surfactant is applied by spraying an aqueous solution thereof on said site or surface. Process according to Claim 2, characterized in that the aqueous solution is substantially free of anionic macromolecules. Process according to any one of the preceding claims, characterized in that the cationic polymer has a molecular weight in the range 1,000 - 5,000,000, in particular between about 10 G00 and about 300,000 and / or that the cationic surfactant has a molecular weight of between about 200 and about 600. Process according to claim 4, characterized in that the cationic polymer is selected from the group consisting of (a) dicyandiamide-formaldehyde condensation polymers, optionally containing as polymerization reactant (s) at least one compound selected from the group consisting of formic acid and ammonium salts, preferably ammonium chloride; (b1 polymers formed by reaction between epihalohydrins and at least one amine, and (c) polymers derived from ethylenically unsaturated monomers containing a quaternary ammonium group. Process according to Claim 5, characterized in that in polymer (b) the epihalohydrin is epichlorohydrin and / or the amine is chosen 46? 667 17 from the group consisting of dimethylamine, diethylamine, methylethylamine, ethylenediamine, triethanolamine and a polyalkylene polyamine. Process according to Claim 6, characterized in that the polymer is represented by the general formula: fl ocuzcaz C fl a I + I fl æ fl gülg - 1-C11g-C11-CH; l; - 'Cilg-CH-CH; --- Iil-CH2 - <.- | | | Cl '| fm fl z fifl g CI 'OH C113 M wherein A is a number in the range 0-500. Process according to claim 5, characterized in that polymer (c) comprises a homo- or copolymer of (i) a vinyl compound, e.g. vinylpyridine or vinylimidazole, quaternized with a C1-C18-alkyl halide or a benzyl halide, preferably the chloride, or with dimethyl or diethyl sulphate, or a vinyl compound, e.g. vinylbenzyl chloride, quaternized with a tertiary amine of the formula NR 1 R 2 R 3, wherein R 1, R 2 and R 3 are each and independently lower alkyl, preferably having 1-4 carbon atoms, with the proviso that one of R 1, R 2 and R 3 may be Cl C15 alkyl; (ii) an alkyl compound, e.g. diallyldimethylammonium chloride; or (iii) an acrylic derivative, e.g. dialkylaminomethyl (meth) acrylamide, which may be quaternized with a C 1 -C 18 alkyl halide, a benzyl halide or dimethyl or diethyl sulfate, a methacrylamidopropyl tri (C 1 -C 4 alkyl, especially methyl ammonium salt or a ( meth) acryloyloxyethyl tri (C 1 -C 4 alkyl, especially methyl) ammonium salt, preferably a halide, eg chloride, methosulfate, ethosulfate or 1 / n of an n-valent anion. Process according to Claim 8, characterized in that the copolymer is derived from a monomer selected from the group consisting of an acrylate (C 1 -C 18) alkyl ester or acrylonitrile, and an alkyl vinyl ether, vinylpyrrolidone and vinyl acetate. Process according to Claim 9, characterized in that the copolymer contains 10-100 mol% of repeating units of the formula: 467 667 15 20 25 30 35 I] 1 a | I3 -ca; R 5 ß and 0-90 mole percent repeating units of the formula: wherein R 1 represents hydrogen or lower alkyl, preferably having 14 carbon atoms, R 2 represents a long chain alkyl group, preferably having 8-18 carbon atoms, R 3, R 4 and R 5 each independently represent hydrogen or lower alkyl, and X represents an anion, preferably a halide ion, a methosulfate ion, an ethosulfate ion or 1 / n of an n- valent jon. Process according to Claim 5, characterized in that polymer (c) comprises a homo- or copolymer of diallyldimethylammonium chloride with repeating units of the formula: ____ //// FH _____ _____ ca: H-ca; z2 "2" H2 U \ ,,., / _ / v r. cH3 cH3 wherein Z represents monomeric units, preferably from a W, (meth) acrylic derivative, such as an acrylamide, an acrylate or methacrylate- (Cl -C13) -alkyl ester or acrylonitrile, or an alkyl vinyl ether, vinylpyrrolidone or vinyl acetate; 5-100%; 0-95% .m is in the range and n is in the range. Process according to Claim 5, characterized in that polymer (c) is derived from monomers of the general formula; + _ + Y m !!! wherein Z and Z ', which may be the same or different, are -CH 2 CH = CHCH 2 - or -CH 2 -CHOHCH 2 -, Y and Y', which may be the same. ma or different, X or -NR'R ", X is a halogen having an atomic weight exceeding 30, n is an integer from 2 to 20, and R 'and R" (i) may be the same or different alkyl groups from 1 to 18 carbon atoms, optionally substituted with 1 to 2 hydroxyl group or (ii) Peri when considered together with N, represents a saturated or unsaturated ring having from 5 to 7 atoms, or (iii) when considered together with N and a oxygen atom, represents the N-morpholino group, especially poly (dimethylbutenyl> -ammonium chloride-bis- (triethanolammonium chloride). Process according to Claim 5, characterized in that polymer (c) is derived from polybutadienes which have been reacted with a lower alkylamine and in which some of the resulting dialkylamino groups have been quaternized, in particular a polymer comprising repeating units of the formulas: I) - fllllg-ÖÜ- b) -K fl g l- ea _ ä; u -cwz-gcz- a) -cwrgï I elk 012 z z 2 912 Ba s.- '+31 IR 1 The molar ratios azbzczd, where R represents lower alkyl, preferably methyl or ethyl. Process according to claim 13, characterized in that the quaternizing agent comprises methyl chloride, dimethyl sulphate or diethyl sulphate and / or that (b + c) is from 10 to 90% and (a + d) is from 90 to 10%. 467 667 10 20 30 (A) UI 20 Process according to any one of the preceding claims, characterized in that the molecular weight of the cationic polymer is from about 20,000 to 300,000, preferably from about 20,000 to 50,000. Process according to one of Claims 1 to 14, characterized in that the molecular weight of the cationic polymer is from about 10,000 to 50,000. Process according to one of Claims 1 to 4, characterized in that the cationic surfactant has the general formula: wherein each R is independently selected from the group consisting of hydrogen , alkyl groups having between about 1 and 22 carbon atoms, aryl groups and aralkyl groups, at least one of said R groups being an alkyl group having at least about 8 carbon atoms and preferably an n-alkyl group having between about 12 and 16 carbon atoms; and wherein X 'is an anion, preferably a halide ion, e.g. chloride, or 1 / n of an n-valent anion. Process according to claim 17, in that two of the characterized R groups are selected from the group consisting of methyl and ethyl, preferably methyl. Process according to Claim 17 or 18, characterized in that an R group is Ph-CH 2 - or Ph-CH 2 -CH 2 -, where Ph is phenyl, preferably benzyl. Process according to one of Claims 17 to 19, characterized in that the surfactant comprises alkyl dimethylbenzylammonium chlorides with alkyl group (s) having between about 12 and 16 carbon atoms. 21. A method according to any one of the preceding claims, characterized in that the polymer or surfactant is applied in an amount of at least about 5 million parts per part of dilution water in a continuous treatment operation. Process according to one of Claims 1 to 20, characterized in that the polymer or surfactant is applied in an amount of at least about 50 million parts per part of dilution water in an intermittent treatment operation. * J 10 467 667 21 Process according to any one of the preceding claims, characterized in that the cationic polymer or surfactant is applied in an amount of up to 500 million parts per part of dilution water. Process according to any one of the preceding claims, characterized in that the charge density of the cationic polymer or the cationic surfactant is in the range of about 0.5-20 milliequivalents / gram, preferably about 1-10 and more preferably about 2-B milliequivalents / gram.