Classifications

• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
  • C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
  • C02F1/56—Macromolecular compounds
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
  • C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
  • C02F1/5245—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents using basic salts, e.g. of aluminium and iron
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2305/00—Use of specific compounds during water treatment
  • C02F2305/12—Inert solids used as ballast for improving sedimentation

Definitions

• the present invention is in the field of water purification compositions and processes.
• the invention relates to the clarification of laundry wash and/or rinse liquor for water saving by re-use.
• Water is becoming a more and more scarcely available commodity, especially in developing countries, where it is not unusual that people have to walk many kilometres to arrive at a water source.
• Washing processes including laundry, dishwashing and other household cleaning processes, require large amounts of water throughout the world.
• the discarded water is a burden to waste water treatment facilities, or to the surface water supply in developing countries.
• One way of saving water is to reuse the water.
• Drinking water purification processes are for instance disclosed in Indian application 918/MUM/2000, or WO2008/092724, both of Unilever. Such systems typically make use of flocculant material to flocculate material out of the solution and a coagulant material to coagulate particles into bigger agglomerates that are easier to separate. Further more, such compositions comprise some inorganic insoluble compound to act as a seed for flocculation on the one hand and as weight to make the floes settle faster on the other hand. Drinking water purification is highly complicated as it requires a product that is suitable for human consumption and should therefore contain very low amounts of bacteria, virus and cyst. It is therefore quite expensive, and the consumer accepts that it takes time to process.
• US2006016761 Ciba, discloses a method of dewatering suspensions in which a high molecular weight, water soluble, cationic polymer flocculant and an encapsulated low molecular weight water soluble, coagulant are mixed with the suspension. According to US2006016761 , the coagulant is not released into the suspension until flocculation has taken place.
• a fast water purification and clarification process for the treatment of household water, especially laundry wash and more typically laundry rinse water remains to be desired. It is therefore an object of the present invention to provide water saving in household process, especially laundry processes, especially hand wash.
• the clarification is achieved in less than 15 minutes, more preferably less than 10 minutes, still more preferably less than 5 minutes, and ideally in 2 to 3 minutes.
• composition not only clarifies the water, but also removes surfactants in the same time.
• composition further reduces the alkalinity of the composition.
• composition is a single composition and does not require the consumer to dose different compositions and/or dose different components in a specific order.
• a paste comprising an electrolyte flocculant and a polymer coagulant dispersed in a continuous phase of the solution of a quaternary ammonium compounds, provides a stable and effective water purification and clarification composition.
• the present invention provides a water purification composition
• a water purification composition comprising: 30-80% by weight of an electrolyte flocculant selected from aluminium and ferric salts; 0.5-5% by weight of a neutral and/or anionically modified polymer coagulant (MW > 100 kD); and 10-40% by weight of a solution of a quaternary ammonium cationic surfactant and/or polymers of quaternary ammonium compounds; wherein the composition is in the form of a paste, wherein the flocculant and the coagulant are dispersed in a continuous phase of the solution of the quaternary ammonium cationic surfactant and/or polymers of quaternary ammonium compounds.
• the invention provides a process for water purification of wash water comprising the steps of dosing 0.3 - 2 g of the composition according to claim 1 per litre of wash water, stirring for at least 10 sec, leaving the particle to settle, and separate the particles from the water.
• wash water any household cleaning water, typically laundry wash water (also referred to as wash liquor), more specifically laundry rinse water (also referred to as rinse liquor).
• the present invention provides a water purification composition and a process for the purification of wash water.
• the water purification composition according to the invention comprises an electrolyte, a polymer, a solution of a quaternary ammonium cationic surfactant and/or polymers of quaternary ammonium compounds.
• the minimum solubility of Al-hydroxide is typically in the pH range of 6.8- 7.5 whereas minimum solubility of Fe-hydroxide typically ranges from pH 4-8. Furthermore, the amount of solid precipitate generated in case of the system treated with Fe-salts is high as the solubility of Fe-hydroxide is lower than Al-hydroxide in the above stated respective pH ranges. This may be used to tune the precipitation kinetics, for instance by means of using combinations of the Al and Fe electrolyte salts. Thus system treated with Fe-salts would also require the pH to be controlled less minutely and hence is more robust. However the residual dissolved Fe-salts impart colour to the water which may have a negative impact on laundry fabrics and hence is less preferred.
• the electrolyte flocculants cause particle aggregation by mainly two well-known mechanisms which include charge neutralization and sweep flocculation.
• the concentration of electrolyte employed in the system regulates the mechanism involved in the process. If the electrolyte is added at a very low concentration which is lower than the solubility limit of the electrolyte, charge neutralization mechanism takes place, in which the surface charge of particles get neutralized by the oppositely charged ions of electrolyte added in the system and thereby reduces the electrostatic repulsion in between particles and promotes the particle aggregation.
• AI(OH) 3 or Fe(OH) 3 When electrolyte is added in excess, it undergoes hydrolysis reaction and as a result AI(OH) 3 or Fe(OH) 3 precipitates out and releases a proton.
• the released proton helps in reducing the alkalinity of laundry liquor and brings the pH close to neutral.
• this AI(OH) 3 or Fe(OH) 3 particles form a porous network structure into which particles get entrapped, and as this matrix settles down the particles are swept away from the system.
• surfactant the charge neutralization is less likely to occur, as an adsorbed surfactant layer on AI(OH) 3 or Fe(OH) 3 particles inhibits aggregation of particles by imparting steric stabilization.
• the electrolyte flocculant is present in the composition in a concentration of 30 to 80% by weight.
• the electrolyte flocculant is preferably present in a concentration of at least 35% by weight, more preferably at least 40% by weight and still more preferably at least 45% by weight of the composition.
• the electrolyte flocculant is preferably present in a concentration of not more than 70% by weight, more preferably not more than 60% by weight and still more preferably not more than 55% by weight of the composition.
• the electrolyte composition may be a solid composition, a liquid composition, or anything in between, including pastes and gels.
• polymer coagulant high molecular weight adsorbing neutral or ionically modified polymers e.g. polyacrylamide.
• the polymer coagulant is present in the composition in a concentration of 0.5 to 5% by weight.
• the polymer coagulant is preferably present in a concentration of at least 1 % by weight, more preferably at least 1.5% by weight and still more preferably at least 2% by weight of the composition.
• the polymer coagulant is preferably present in a concentration of not more than 4.5% by weight, more preferably not more than 4% by weight and still more preferably not more than 3% by weight of the composition.
• the polymer coagulant is preferably selected from neutral and/or anionically modified adsorbing polymers.
• the most preferred polymers are poly acrylamides.
• the polymer preferably has a high molecular weight of MW >100 kD.
• the molecular weight (MW) is typically less than 5000 kD, more preferably less than 2000 kD, still more preferably less than 1000 kD.
• the polymer is preferably water soluble.
• the most preferred polymer is a neutral and/or anionically modified polyacrylamide polymer having molecular weight > 100kD.
• solution of a quaternary ammonium cationic surfactant is meant of a solution of a quaternary ammonium cationic surfactant and/or polymers of the quaternary ammonium compounds.
• the surfactant gets depleted by adsorbing on AI(OH) 3 or Fe(OH) 3 precipitate, it does not get completely removed as the extent of removal depends on the starting concentration in the wash liquor and/or the kinetics of removal. Therefore the treated water containing left over surfactant can not be considered to be re-usable "fresh" water in the context of the present invention.
• the cationic surfactant is added to the system to remove the remaining anionic surfactant by precipitation, which is having much faster kinetics compared to the adsorption.
• the solution of the quaternary ammonium compound is present in the composition in a concentration of 10 to 40% by weight, more preferably 20 to 40% by weight.
• the cationic surfactant solution is preferably present in a concentration of at least 24% by weight and more preferably at least 26% by weight of the composition.
• the cationic surfactant is preferably present in a concentration of not more than 35% by weight, more preferably not more than 33% by weight of the composition.
• the quaternary ammonium surfactants are preferably halides of Benzalkonium, Cetyl- trimethyl-ammonium, Tetradecyl-trimethyl-ammonium, Dodecyl-trimethyl-ammonium, Stearyl-trimethyl-ammonium, Octadecyl-trimethyl-ammonium, Dodecylpyridinium, Cetylpyridinium, Tetrabutyl-ammonium, Tetraheptyl-ammonium, 1 ,3-Decyl-2-methyl- imidazolium, 1-Hexadecyl-3-methyl-imidazolium, Didecyl-dimethyl-ammonium, Didecyl-dimethyl-ammonium.
• Polymers of quaternary ammonium compounds are also suitable for use in the composition.
• the most preferred compounds of this class are Polydiallyldimethylammonium chlorides (also known as PolyDADMAC).
• Polymers of quaternary ammonium compounds typically have a molecular weight of between 10 and 1000 kD, preferably between 40 and 400 kD.
• halide is chloride. Fluorides and iodides are contemplated in the context of the invention for their biocidal activity. Bromides are typically not preferred due to their toxicity.
• BAC benzalkonium chloride
• PolyDADMAC class of PolyDADMACs
• quaternary ammonium cationic surfactants and polymers of the quaternary ammonium compounds are commercially available in solid lump form, often giving toxic and irritating fumes. Additionally it is difficult to mix them when added to a laundry liquor and it is difficult to process when paste is made using such compounds.
• the cationic surfactant is typically dosed in the form of a solution of the cationic in water, wherein the ratio of cationic surfactant to water is preferably in the range of 4: 1 to 1 :2, more preferably 2: 1 to 1 : 1 , which is found to be easier to mix and process.
• Buffer 1 the ratio of cationic surfactant to water is preferably in the range of 4: 1 to 1 :2, more preferably 2: 1 to 1 : 1 , which is found to be easier to mix and process.
• a buffer may be incorporated in the formulation in cases where a wide pH variation in the wash liquor is found.
• the pH variability is observed due to various reasons like the source water quality, the variable dosage of detergent formulations, detergent formulation with different compositions and different wash habit of consumers.
• the buffer may be carbonate or phosphate system. It may be present in a range of between 5 to 20 % of total composition.
• the composition may optionally comprise a filler selected from inorganic material which is non reactive to any other ingredients present in the system. This is preferably solid with a very high density.
• the inorganic filler is preferably selected from natural or synthetic clays and water insoluble inorganic salts.
• Preferred fillers include feldspar (KAISi 3 0 8 ), kaoline, bentonite and Attapulgite, as well as alumina (including silica alumina compositions) and MgO
• the inorganic filler is thought to increase the number of particles.
• the increased particle number density results in faster floe formation.
• the floes formed are also heavier due to the extra mass of the filler and therefore settle faster.
• the presence of fillers helps nucleate the AI(OH) 3 or Fe(OH) 3 network formation thereby improves the sweep flocculation kinetics. Additionally due to its higher density, it is thought to increase the settling velocity of the floe and improve the overall flocculation kinetics.
• the fillers are found to play a role as a carrier of functional ingredient like cationic surfactant and/or cationic polymer which is found to aid in the removal of the residual surfactant present in the system by precipitation or complexation.
• the inorganic filler is present in the composition in a concentration of 5 to 35% by weight.
• the inorganic filler is preferably present in a concentration of at least 10% by weight and more preferably at least 15% by weight of the composition.
• the inorganic filler is preferably present in a concentration of not more than 30% by weight, more preferably not more than 25% by weight of the composition.
• the most preferred filler would be the 1 : 1 clays e.g. Kaolin or Feldspar.
• the composition is in the form of a paste or gel.
• the rate of dissolution of the electrolyte is typically somewhat higher than for the coagulant. This is beneficial to the invention. This effect may be further enhanced, by making the electrolyte particles smaller and/or less dense than the coagulant particles.
• the polymer coagulant When the polymer coagulant is in particulate form it typically dissolves slowly.
• the product format is a gel or paste, wherein the flocculant and the coagulant are dispersed in a continuous phase of the solution of the quaternary ammonium cationic surfactant and/or polymers of quaternary ammonium compounds.
• An alternative way of solving the dissolution issue, that separated the flocculant electrolyte and the polymer coagulant is to physically separate the two in the packaging, e.g. by providing 2 dual compositions, or a single unit-dose sachet comprising 2 chambers or pouches. Such physical separation brings about more cost for the packaging and more work for the consumer and is not the most ideal solution for those perspectives, and therefore not preferred by the consumer. Water purification process
• the invention further provides a process for the purification of water comprising the steps of dosing the composition according to the invention to the wash water, stirring for at least 10 sec, leaving the particle to settle, and separate the particles from the water.
• composition according to the invention should be dosed per litre of wash water.
• At least 0.4 g/L is dosed, more preferably even at least 0.5 g/L. Dosing more than 1 g/L is not providing much more improvement of the purification effect, while dosing more than 2 g/L may even be detrimental to the effect obtained.
• the wash water comprising the composition must be stirred for at least 10 second, preferably at least 20 seconds, but typically not more than 1 minute. Stirring may be done with any kind of device, such as a spoon, stick or any other stirring device.
• the settling plate configuration includes a means for keeping the settling plates together, e.g. a central rod, to which the plates are connected.
• the settling plate configuration typically comprises between 3 and 10 plates, preferably between 4 and 8 plates.
• the plates are at a distance relative to each other of between 2 and 15 cm, preferably between 4 and 10 cm.
• kits comprising a bucket and the settling plate configuration, as well as at least one dose of the composition according to the invention and a set of instructions.
• the bucket may further comprise a water discharge means, e.g. a stop cock or a valve or tap arrangement, at the bottom.
• a water discharge means e.g. a stop cock or a valve or tap arrangement
• the water discharge means in the context of the invention has at least 2 states, one open, and one closed. This will enable water to be drained from the bucket into another container when the bucket is placed at elevated height over another container.
• Example 1 paste composition
• a paste is prepared of PAC and polymer dispersed in a continuous phase of the BAC solution (1 : 1 BAC and water), compared to a dual chamber sachet comprising BAC solution in one chamber and the other ingredients in another chamber, wherein the either the first or the second sachet is dosed first.
• An artificial consumer rinse liquor was prepared, containing soil, surfactant, soda, electrolyte and hardness ions.
• Rinse liquor soil is a mixture of: (A) 0.25 g/L model soil which is a mixture of 90% Clay, 5% Silica, 2.5 % Carbon soot, 1.25% Fe 2 0 3 and 1.25% Fe 2 0 4 .
• the table shows that paste give good results, while when using the 2 chamber sachet the result is dependent on whether the contents of the right chamber was dosed first.
• the single composition paste thus provides a consumer benefit over a dual chamber composition, without hampering the efficacy.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Hydrology & Water Resources (AREA)
• Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Water Supply & Treatment (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Separation Of Suspended Particles By Flocculating Agents (AREA)
• Detergent Compositions (AREA)

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• 2011
  • 2011-12-14 MX MX2013007184A patent/MX2013007184A/es unknown
  • 2011-12-14 EP EP11796699.4A patent/EP2655263A1/de not_active Withdrawn
  • 2011-12-14 CN CN201180062640.XA patent/CN103282314B/zh not_active Expired - Fee Related
  • 2011-12-14 WO PCT/EP2011/072685 patent/WO2012084623A1/en active Application Filing
  • 2011-12-14 AU AU2011347796A patent/AU2011347796B2/en not_active Ceased
  • 2011-12-14 BR BR112013015919-7A patent/BR112013015919B1/pt not_active IP Right Cessation
• 2013
  • 2013-06-11 ZA ZA2013/04275A patent/ZA201304275B/en unknown

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