HK1009062B

HK1009062B - Process for purifying and reusing surfactant-containing waste waters

Info

Publication number: HK1009062B
Application number: HK98109787.1A
Authority: HK
Inventors: Lerche Elke; Kneist Karin; Rohbeck Hartmut; Hillemann Doris; Schwarz Ralf
Original assignee: Buck Werke Gmbh & Co.
Priority date: 1994-03-08
Filing date: 1995-02-24
Publication date: 1999-05-21

Description

The invention relates to a process for purifying and reusing waste water from washing processes containing tensile materials as defined in the general concept of claim 1.

The treatment and reuse of surfactant-containing wastewater, in particular from laundries, car washes and household surfactants, is a technological challenge, as surfactants are by nature extremely hostile environments for organisms of all kinds, in particular for microorganisms of mixed bionosis.

In addition, industrial waste water from washing processes, in particular laundry waste or vehicle washing waste, is often a highly complex chemical mixture which is difficult to clean or reuse.

In particular, the waste water from laundries is naturally highly dependent in its quantitative and qualitative composition on the detergents used in the washing or cleaning processes.

Such universal detergents are generally composed of a variety of chemically diverse substances, in particular anionic and non-ionic surfactants, builders, co-builders, bleaches, bleaching activators, greying inhibitors, corrosion inhibitors, stabilisers, foam inhibitors, enzymes, optical brighteners, and fillers and auxiliaries.

The anionic and non-ionic surfactants include alkylbenzolesulfonate, alcohol sulphate and alcohol hydroxylate.

The most common building materials are zeolite A, sodium triphosphate and sodium carbonate, but the current trend is to largely avoid phosphates for environmental reasons and to replace them with, for example, zeolite and/or other silicates.

Such builders are needed to increase the cleaning effect of the surfactants by many times.

The co-builder is mainly polycarboxylate.

Perborates, in particular sodium perborate, and tetraacetylethylenediamine are used as bleaching agents.

The main graying inhibitors are carboxymethylcellulose and cellulose ether.

The main use of corrosion inhibitors is alkaline silicates.

Phosphonates are used as stabilizers and soaps, silicone oils and/or paraffins are used as foam inhibitors.

The main enzymes used are proteases and amylases, but sometimes also lipases.

In addition, optical brighteners of the stilbene or biphenyldistilyl type are often used.

In addition to colouring agents, fragrances and excipients, sodium sulphate is often used as a filler or production aid.

The use of all-purpose detergents in laundry facilities is moving towards a greater elimination of phosphates as builders and replacing these phosphates mainly by zeolites, soaps, citrates and amines, in particular tri- and monoethanolamines.

In particular, in the USA and Japan, as well as in the Netherlands, Germany, Switzerland, Austria and Italy, practically all phosphates-free detergents are used and are therefore found in the waste water of laundry facilities.

A number of other substances are also released into the waste water in vehicle washing plants, such as those selected from: car care products, in particular waxes based on natural waxes or polyethylene; polishing substances; greases; lubricants, in particular silicone oils, silicone oils, motor oils, gear oils, fuels, such as petrol and diesel fuels; antifreeze, in particular glycols; amino oxides; quaternary ammonium compounds; betaines; dialkyldimethylammonium salts, in particular chlorides; streuzal; and mixtures thereof.

The complex composition of the washing and cleaning solutions containing surfactants described at the beginning of this article makes the chemistry of the waste water extremely complex. Due to legal and environmental requirements, surfactants must generally be treated before being discharged into the sewer or a drainage system. The type, type of treatment and the amount of effort required depend on the type of cleaning, the impurities used and the local regulations or regulations. In the case of acid or alkaline cleaners, the waste water must be neutralized. In the case of sub-alkalized oils, emulsion separation must be carried out.

In the case of waste water treatment, the surfactants contained in the application solutions, insofar as they are insoluble in oil, are also largely removed during the separation of the oils and fats.

The precipitation or flocculation of aluminium or iron phosphates or their hydroxides can greatly reduce the chemical oxygen requirements (CSB) of the waste water, which is the most important factor in determining the waste water discharge, in so far as it is produced by surfactants or other adsorbable organic substances.

Another treatment option for surfactants is ultrafiltration, which is expensive and expensive.

Err1:Expecting ',' delimiter: line 1 column 476 (char 475)

For example, ultrafiltration of laundry water has been promoted in DE-A 35 13 940, particularly for the recovery of water and unused detergents. However, such ultrafiltration plants lead to high investment and maintenance costs.

In addition to this investment and maintenance cost of ultrafiltration systems, the effect described above of only incomplete stress-resistance leads to highly stressed wastewater that should not be drained.

A similarly complex process for the treatment and reuse of washing and rinsing water is revealed in DE-A 41 24 915, which provides instructions for filtering part of the waste water containing surfactants and for treating part of the waste water to produce rinsing water by flotation.

This method, while designed to avoid salinization, also involves the addition of demineralized fresh water, which is costly to desalinate by means of ion exchangers, to the rinsing water obtained from the waste water, resulting in a moderate salt concentration.

Preferably this method uses state-of-the-art metal salts as flotation aids.

This state-of-the-art method thus has the disadvantage of having to dispose of the fleet sludge generated during flotation.

In addition, the waste water is treated by pressure relief flotation, which is technically expensive and involves relatively high investment and maintenance costs.

Another way of doing the flotation according to the DE-A 41 24 915 doctrine is to do so-called electroplotting instead of metal salt treatment, which has the disadvantage that electroplotting systems are relatively expensive and does not solve the problem of disposing of the resulting tensile sludge.

Another solution approach for the treatment of waste water, as it occurs after washing clothes in large laundries, is described in DE-A 40 35 433 where the process described is to mix oil-in-water emulsions produced in large laundries with the organic solvent perchlorethylene, to convert the waste water into a liquid containing mainly water and a small amount of oil, which is first dissolved by ultrafiltration in water and oil for disposal, and then into a second solution to dissolve the pollutant and oil-containing liquid phase, which is dissolved and dissolved by dissolving the solvent in an oil-in-oil disposal.

This state-of-the-art method has the significant disadvantage, however, that it uses an organic solvent which is ecotoxically dangerous and which is sure to enter the environment at least in trace amounts.

Furthermore, DE-A 33 05 238 describes a method for biological purification of water after prior purification by a pre-filter, whereby the water to be purified is circulated in a separate filter circuit. The filter circuit also provides ventilation and oxygenation by means of an air-driven mammoth pump. The task of DE-A 33 05 238 is to create an efficient filter that does not require cleaning under normal conditions or that allows the automatic separation of sludge, dirt or the like.

In any case, such a filter can still be used for intensive fish farming, because the filter is a combination of biological filter and coarse filters, since lavackies are used as filter material.

This tank filter, according to the state of the art of DE-A 33 05 238, can be switched to an activated carbon filter for the absorption of non-degradable substances.

Although DE-A 33 05 238 provides that the aquarium filters described therein may also be used for the treatment of waste water from laundries and other wetlands and for the treatment of industrial waste water, no information is provided on the nature of the waste water, in particular the ratio of stressed waste water to mixed biozones.

Err1:Expecting ',' delimiter: line 1 column 69 (char 68)

The problem of biological treatment of surfactant-containing waste water can also be seen in the fact that the methods required by the European Community for determining the primary degradation of surfactants, the so-called OECD screening test or the OECD confirmatory test, are based on a test duration of 19 days for the screening test and 21 days for the confirmatory test.

The OECD screening test defines surfactants as biodegradable if they have been degraded to at least 80% after 19 days.

This is why there is no biological process for the treatment and reuse of sewage containing surfactants.

Thus, the present invention is intended to provide a method for the treatment and reuse of surfactant-containing waste water that is effective, rapid and cost-effective.

The solution to this problem is to be found in the characteristics of the claim 1.

The method of purification and reuse of surfactant-containing waste water according to the invention is ideally suited for purifying waste water from washing processes, in particular washing plants, car washes and private households, and reusing the purified and treated water as feed water for the washing plant or for rinsing, cleaning or greenhouse irrigation.

The method of the invention thus makes it possible to recover up to 95% of the wastewater in collaboration with an adsorber stage by means of a biological step, namely a bioreactor with a mixed biozonosis specific to the wastewater, to make it usable in the washing process.

The most surprising aspect is that in a few hours to a day, the biological treatment of waste water containing surfactants can be achieved to the extent that the organic content is reduced by 80 to 90%, especially since the OECD screening test and the OECD confirmatory test assume that surfactants are biodegradable if they are reduced to 80% within 19 and 21 days, respectively, which is equivalent to a slow degradation of surfactants for sewage engineering purposes.

Any remaining biodegradable ingredients, if any, are removed from the water in a downstream adsorber stage and disposed of appropriately after the adsorber is exhausted.

Activated carbon is the preferred adsorbent material, but any other adsorbent material such as silica gel, silica gurl or other materials with large inner surface area can also be used as adsorbents.

The method of the present invention requires only the addition of about 5 to 20% fresh water, which saves enormous amounts of water.

A major advantage of the method of the invention using a bioreactor is the feasible cycling of the washing water, which results in effective savings in drinking and waste water, which, given the tendency to rise sharply in the prices of drinking water supply and waste water treatment, have a very positive impact on the development of operating costs and on the return on investment.

Another important advantage of the method of the invention is its high environmental compatibility.

The method of the present invention is a far superior alternative to the methods of waste water treatment used to date, such as flocculation, neutralization or ultrafiltration, because of the use of a bioreactor, as it eliminates the additional use of chemicals for chemical waste water treatment, for example, precipitation, flocculation and/or flotation.

In addition, the water purified by the biological process of the invention has a low hardness, which in turn prevents calcification in the piping system during the planned process water cycle and also allows a significant reduction in the use of detergents.

The method according to the invention thus makes a substantial contribution to reducing the environmental impact.

A particular advantage of the bioreactor is that no large amounts of biomass are transferred, no continuous removal of excess biomass takes place and no biomass recycling is required.

Claim 2 refers to surfactant effluents which can be preferentially purified by the method of the invention; in particular, the method according to the present invention is suitable for purifying surfactant effluents from laundries, car washing plants, container washing plants, especially food containers such as bottles, jars or the like, medical washing plants, e.g. for surgical instruments and/or containers or private households.

If household waste water containing stress is used, the preferred use of the waste water is exclusively the fecal waste water as stated in claim 3, which can be easily achieved by collecting and treating the stressed waste water and the fecal waste water separately.

The sewage containing surfactants from private households is preferably disinfected after cleaning and before reuse, for example by high-energy UV light and/or by means of an ozonator, and can then be used, for example, in the domestic water cycle, for example for flushing toilets or as cleaning water or irrigation.

This saves enormous amounts of drinking water and drastically reduces the amount of waste water discharged through the municipal sewage system. Furthermore, the waste water discharges for the household are reduced. The inventive process is particularly attractive for hotels, pension houses and restaurants with a high flow rate of drinking water.

According to claim 4, waste water containing almost all types of surfactants, in particular those from detergents, can be treated.

The dependent claims 5, 6 and 7 represent advantages in the development of the method according to the invention, since the substances listed therein are presently present in greater quantities in all-purpose detergents used in laundries and in washing processes, e.g. in car washes and/or in private households.

According to claim 8, it is preferable to use the method of the invention on waste water with an alkaline pH, in particular a pH of about 8 to 11.

According to claim 9, waste water with a manganese and/or iron content of less than 1% is preferably treated, although it is of course also possible to perform the procedure of the invention with higher manganese and/or iron or heavy metal contents, but if heavy metal contents become too high, appropriate measures such as precipitation, flocculation or additional adsorption may be used.

According to claim 10, waste water with a chemical oxygen demand (CSB) of approximately 150 to 2000 mg/l O2 may be used.

This has the advantage that the present method can be used to treat most industrial-scale sewage and that the present invention can in principle treat all sewage containing sewage.

For example, it is quite possible to carry out the present procedure with the waste water of a large kitchen sink in order to reuse it as municipal water.

However, the present method is of particular importance for the treatment of textile washing waste water.

The use of a column bioreactor has the advantage of optimal process management.

The advantage of using a pit or screen cascade reactor as claimed in claim 11 is that such a bioreactor type allows for streamlined process management with a large surface area and easy cleaning capability of the bioreactor.

The use of a column reactor with internal stationary surfaces as claimed in claim 12 has the advantage of facilitating the oxygen supply to the bioreactor and of allowing a more intimate contact of the biofilm on the internal surfaces of the bioreactor in the form of a mixed bionose.

The advantage of sending the bioreactor in direct current with the waste water to be purified with air and/or oxygen is that this creates optimal aerobic conditions for mixed bioizonisation inside the reactor.

The bioreactors used for the present invention are preferably made of inert plastics and/or metals as described in claim 13.

According to claim 14, a laundry-wastewater-specific mixed bio-ionose, which is appropriate to the degradation of the wastewater constituents, settles and must be inoculated if necessary. The laundry-wastewater-specific mixed bio-ionose used for the present invention contains essentially adapted aerobe heterotrophic bacteria as well as aerobe heterotrophic animal individuals and multicellular animal organisms, particularly microorganisms.

Wherever air is supplied to the bioreactor - usually at the bottom - there are fluctuations in oxygen and/or nutrient concentrations.

It is essentially home to bacteria that easily tolerate such fluctuations in oxygen and/or nutrients.

In addition, this part of the mixed bionose of the washing area has a collection of filamentous sulphur bacteria, which initially contribute the most to the degradation of organic matter in the waste water.

If one goes to compartments higher up relative to the airflow, one finds protozoa, especially flagellates, which have a particularly high pH tolerance of 4.7 to 9.6 and above.

The next stage of mixed bioizonosis is the formation of cilia, particularly uronema marinum, and the extensive purification of vorticella and oxytrichia fallax.

It is particularly noteworthy that flagellate and ciliate e.g. coliforms and other bacteria are eaten, preventing their uninhibited reproduction.

In addition, the mixed biozones of the washing area are also home to nematodes and rotators, microscopic multicellular animals that eat and digest dead biomass, fine particles, bacteria and cilia.

These microorganisms, as described above, constitute a mixed bio-ionose characteristic of the present invention, which is capable of decomposing stressed wastewater, since it was obtained from unexplained stressed industrial wastewater and deposited on the internal surfaces of the bioreactor of the present invention.

The advantage of using activated carbon as an adsorbent material according to claim 15 is that it provides a highly active adsorbent material with a high adsorption capacity, which is also cost-effective and easily disposable.

The water purified according to the method of the invention has an advantageous pH of about 6 to 10, in particular about 8 to 9, according to claim 16, so that it is close to the neutral point and can be re-inserted into a washing cycle without further adjustment of the pH.

However, if neutral or slightly acidic water is required, the pH can be adjusted to 7 or below, for example by adding CO2.

The measures of claim 17, that about 80 to 95% of the waste water used is recovered as purified water for re-feeding into a washing process, result in a very economical process and a very rapid return on investment.

The water loss from the process is advantageously replaced by the addition of fresh water rather than by the primary addition of demineralized or entioned water, according to claim 18.

According to claim 19, the waste water to be treated is treated for between one and ten hours, in particular between two and six hours, preferably for about four hours in the bioreactor, with the bioreactor then being run in a cyclical mode, if necessary.

According to claim 20, the water leaving the bioreactor thus retains only about 5 to 20% of the organic content of the injected wastewater, which can then be advantageously easily removed via the down-switched adsorber, so that the adsorber has long life spans before it needs to be disposed of or replaced.

It is advantageous to add specific nutrients for mixed bio-ozonogenic micro-organisms to the waste water to be treated, if necessary, as claimed by claim 21, - if a specific nutrient from the treated waste water is not available to the micro-organisms.

According to claim 22, the process of the invention can also remove the excipients specified therein from water, which is therefore particularly advantageous as the excipients specified in claim 22 are present in virtually every universal detergent and/or cleaning product.

Claim 23 lists preferred substances or mixtures of substances as found in the waste water of vehicle washing plants.

If necessary, when treating waste water containing surfactants in car washes, oil must be removed by conventional means and the oil phase must be disposed of.

Further advantages and features of the present invention are shown by the description of an example of an embodiment and by the drawings.

It shows:Fig. 1the process according to the invention in the example of cleaning laundry wastewater, in diagrammatic form;Fig. 2the process according to the invention in the example of cleaning wastewater from car washing plants; andFig. 3the process according to the invention in the example of cleaning household wastewater.

Example 1

The waste water from a washing plant 1 is collected in a stacking tank 3, the flushes and textile fabric are largely separated by filter sieves 2 and the volume of the tank is sized to accommodate a second day's supply of waste water in the example case.

The collected waste water shall have the following values: Other

CSB

pH	8,0
Härte	5,6° dH
Leitfähigkeit	1670 µS/cm
Gesamtmenge organische Bestandteile	TOC = 82 mg/l

At the bottom end of the bioreactor 4 air is introduced into the bioreactor 4 so that aerobic conditions are formed. At the top end of the column bioreactor 4 the biologically treated water leaves the bioreactor 4 and is fed to an activated carbon column as adsorber 7. The water, now also adsorptively purified, leaves the activated carbon packed adsorber 7 via the line 8 and is collected in a stack of containers 9 and if necessary re-inserted in the laundry 1 container 10 times, with fresh water being fed in at 5 to 20% capacity.

The water treated by the method of the invention has the following values: Other

CSB

pH	8,2
Härte	5,6° dH
Leitfähigkeit	1670 µS/cm
Gesamtmenge organische Bestandteile	TOC = 7 mg/l

The bioreactor 4 is flushed approximately every 35 weeks, with its residual 11 which is mainly biomass, being recycled or disposed of.

The wastewater to be treated stays in bioreactor 4 for four hours.

Err1:Expecting ',' delimiter: line 1 column 149 (char 148)

This is done in a convenient and simple way by depositing several samples of biofilms from industrial washing plants, in the case of textile washing plants which have been in operation for some time, on the inner surfaces of the bioreactor, preferably a cascade bioreactor. This is done by suspending the biofilm material from the relevant industrial waste water in water, if necessary with additional nutrients such as phosphates and/or nitrates and/or amino acids, and by depositing more or less of this synthetic wastewater for several days in aerospace conditions.

This inoculation of the bioreactor can be repeatable, always with the result that the organic content of the surfactant-containing waste water is reduced by about 80%.

Example 2

The water recovery system from vehicle washing plants 15 can be operated as shown in Figure 2.

In Figure 2, the same parts as in Figure 1 are given the same reference marks as in Figure 1.

The waste water from the car wash is collected in a special stacking tank 3 The volume of the tank is sized to store a relatively uniform amount of mixed waste water (about 0.5 to 1.0 daily waste water volume) The mechanical pre-treatment of sand and solids is done by sedimentation in the stacking tank 3 The oil layer formed on the surface is removed, collected and disposed of appropriately.

In bioreactor 4, the resulting waste water is purified in a continuous flow under defined aerobic conditions and the addition of special nutrients.

The biologically purified water is fed into a mechanical purification step 7 to remove worn-out bioflores, then collected in a second stack 9 and fed back into the vehicle washing system 15 as needed.

Example 3

The waste water cycle performance for private households or larger dwellings (hotels, pensions, etc.) is similar to that described in examples 1 and 2 and is schematically shown in Figure 3.

All wastewater 16 generated in the household, excluding faecal wastewater discharged directly into the public sewerage system, is collected in a container 3 of sufficient size and continuously fed to the bioreactor 4 for purification.

The biological cleaning is followed by a post-treatment stage 7 to remove any worn-out bioflores. It is also recommended to disinfect the water to prevent biological growth in the second stack tank 9. The purified water is available for the domestic water cycle, e.g. for toilet flushing, washing, cleaning or boiling, thus helping to save considerable quantities of drinking water. Additional benefits can be obtained by reducing the use of waste water in this described cycle, for example by directing water from the 18th step of the 19th step into the second step of Regulation 9.

The present invention thus provides for the first time a biological degradation process for stressed waste water, which is not limited to the washing processes described in the example, but can be used to advantage in many types of water, detergent and detergent intensive processes, whereby the mixed bio-ionosis will have a correspondingly different biological composition.

Claims

Method of cleaning and reusing surfactant-containing waste waters from wash processes, the water leaving the wash process, after separation of settling and suspended materials, being passed to a collector; and this physically pre-cleaned water being passed to a bioreactor operating under aerobic conditions, characterised in that
the bioreactor is columnar and has a compartmented mixed biozonosis containing multi-celled animal organisms, and being specific to surfactant waste water, for biological processing of the waste water, and in that the bioreactor is supplied with air and/or oxygen in the same current as the waste water to be cleaned;

in that the water leaving the bioreactor is passed to an adsorber; and

in that the biologically and physically cleaned water leaving the adsorber is again passed to the wash process as drinking water.
Method according to claim 1, characterised in that waste waters are used which originate from laundries; vehicle washing plants; washing installations for containers, particularly foodstuffs containers such for example as bottles, glasses or the like; medical washing installations, e.g. for surgical instruments and/or containers; or private households.
Method according to claim 1 or 2, characterised in that surfactant-containing waste water from private households, preferably exclusively human waste, is used; and the purified waste water is disinfected before re-use.
Method according to one of claims 1 to 3, characterised in that waste water is used which contains surfactants which are selected from the group comprising:
anionic surfactants, particularly carboxylates, soaps fatty alkylethercarboxylates, alkylsulphates, particularly sodium dodecylsulphate (SDS) alkylphosphates, alkyletherphosphates, alklybenzylsulphonates, olefinesulphonates, alkanesulphonates, and sulfosuccinic acid esters;

non-ionic surfactants, particularly oxethylates, fatty acid alkanolamides, polyhydroxy compounds, alkyloligoglycosides and alkylpolyglycosides; and

cationic surfactants, particularly tetraalkylammonium salts, imidazolinium salts, and their mixtures.
Method according to one of claims 1 to 4, characterised in that waste water is used which additionally contains anions which are selected from the group comprising:
inorganic anions, particularly nitrates, nitrites, sulphates, sulphites, sulphides, hydrogen sulphites, phosphonates, phosphates, oligo- and polyphosphates, hydrogen phosphates, hydroxides, halogenides, particularly chlorides, silicates; and

organic anions, particularly carboxylic acid anions, preferably acetates; substituted carboxylic acid anions, particularly hydroxycarboxylic acids such as citrates and tartrates;
and their mixtures.
Method according to one of claims 1 to 5, characterised in that waste water is used which additionally contains cations selected from the group comprising: alkali cations, particularly sodium, potassium cations; earth alkali cations, particularly calcium and magnesium cations; iron cations, manganese cations and other heavy metal cations; and their mixtures.
Method according to one of claims 1 to 6, characterised in that waste water is used which additionally contains chelate formers and/or chelate complexes, particularly chelate formers for bivalent cations, particularly calcium and/or magnesium, preferably EDTA and/or EGTA or their metal complexes.
Method according to one of claims 1 to 7, characterised in that waste water is used which has an alkaline pH, particularly a pH of about 8 to 11.
Method according to one of claims 1 to 8, characterised in that waste water is preferably used which has a manganese and/or iron content of < 1%.
Method according to one of claims 1 to 9, characterised in that waste water is used which has a chemical oxygen requirement (COR) of about 150 to 2000 mg/l O₂, preferably about 500 to 800 mg/l O₂.
Method according to one of claims 1 to 10, characterised in that a perforated or screen base cascade reactor is used as a bioreactor.
Method according to one of claims 1 to 10, characterised in that a column reactor with surfaces immovable in the interior is used as a bioreactor.
Method according to one of claims 1 to 10, characterised in that bioreactors made of inert plastics and/or metals are used.
Method according to one of claims 1 to 13, characterised in that if required a mixed bionozosis, which is specific to surfactant waste water, particularly specific to waste water from washing plant, is previously cultivated and colonised on the inner surfaces of the bioreactor.
Method according to one of claims to 14, characterised in that activated carbon is used as an absorber, the absorber preferably being in the form of a column.
Method according to one of claims 1 to 15, characterised in that the cleaned water has a pH of about 6 to 10, particularly about 8 to 9.
Method according to one of claims 1 to 16, characterised in that about 80 to 95% of the waste water used is recovered for renewed return into a washing process as purified water.
Method according to one of claims 1 to 17, characterised in that water losses caused by the process are replaced by an addition of fresh water.
Method according to one of claims 1 to 18, characterised in that waste water to be cleaned is processed for between 1 and 10 hours, particularly between 2 and 6 hours, preferably about 4 hours in the bioreactor, the bioreactor being if necessary operated in circulatory operation.
Method according to one of claims 1 to 19, characterised in that water leaving the bioreactor still contains only about 5 to 20% of the organic contents of the waste water fed in.
Method according to one of claims 1 to 20, characterised in that if necessary additional nutrients for the mixed biozonotic micro-organisms are added to the waste water to be cleaned.
Method according to one of claims 1 to 21, characterised in that waste water contains washing aids, selected from the group comprising:
builders, particularly ortho- and condensed phosphates, borates, silicates, alkalis, zeolites, complex formers;

co-builders, particularly polycarboxylate;

bleaching agents, particularly perborates; and bleach activators;

greying inhibitors, particularly carboxymethylcellulose, cellulose ether;

stabilisers; foam inhibitors;

enzymes, particularly lipases, proteases and amylases;

optical brighteners, particularly stilbene- and biphenyldistyryl derivatives, and

fillers, particularly sodium sulphate, pigments; perfumes;
and their mixtures.
Method according to one of claims 1 to 22, characterised in that the waste water contains materials selected from the group comprising: servicing substances for motor vehicles, particularly waxes on a basis of natural wax or polyethylene; polishing substances; grease materials, lubricants, particularly silicon greases, silicon oil, engine oils, gear oils; fuels, e.g. petrol and diesel fuels; anti-frost agents, particularly glycol; amine oxides; quaternary ammonia compounds; betains; dialkyldimethyl ammonium salts, particularly chlorides; scattering salts; and their mixtures.