WO1995027681A1 - Procede et systeme de purification d'une solution caustique contaminee alimentee en continu - Google Patents

Procede et systeme de purification d'une solution caustique contaminee alimentee en continu Download PDF

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Publication number
WO1995027681A1
WO1995027681A1 PCT/EP1995/001277 EP9501277W WO9527681A1 WO 1995027681 A1 WO1995027681 A1 WO 1995027681A1 EP 9501277 W EP9501277 W EP 9501277W WO 9527681 A1 WO9527681 A1 WO 9527681A1
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WO
WIPO (PCT)
Prior art keywords
membrane
process according
permeable
solution
caustic
Prior art date
Application number
PCT/EP1995/001277
Other languages
English (en)
Inventor
Henia Yacubowicz
Jorge Yacubowicz
Reuven Katraro
Motty Perry
Original Assignee
Membrane Products Kiryat Weizmann Ltd.
Whalley, Kevin
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Membrane Products Kiryat Weizmann Ltd., Whalley, Kevin filed Critical Membrane Products Kiryat Weizmann Ltd.
Publication of WO1995027681A1 publication Critical patent/WO1995027681A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
    • B01D61/027—Nanofiltration
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D1/00—Oxides or hydroxides of sodium, potassium or alkali metals in general
    • C01D1/04—Hydroxides
    • C01D1/28—Purification; Separation
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D1/00—Oxides or hydroxides of sodium, potassium or alkali metals in general
    • C01D1/04—Hydroxides
    • C01D1/28—Purification; Separation
    • C01D1/32—Purification; Separation by absorption or precipitation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C227/00—Preparation of compounds containing amino and carboxyl groups bound to the same carbon skeleton
    • C07C227/38—Separation; Purification; Stabilisation; Use of additives
    • C07C227/40—Separation; Purification
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C229/00—Compounds containing amino and carboxyl groups bound to the same carbon skeleton
    • C07C229/02—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton
    • C07C229/04—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being acyclic and saturated
    • C07C229/06—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being acyclic and saturated having only one amino and one carboxyl group bound to the carbon skeleton
    • C07C229/10—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being acyclic and saturated having only one amino and one carboxyl group bound to the carbon skeleton the nitrogen atom of the amino group being further bound to acyclic carbon atoms or to carbon atoms of rings other than six-membered aromatic rings
    • C07C229/16—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being acyclic and saturated having only one amino and one carboxyl group bound to the carbon skeleton the nitrogen atom of the amino group being further bound to acyclic carbon atoms or to carbon atoms of rings other than six-membered aromatic rings to carbon atoms of hydrocarbon radicals substituted by amino or carboxyl groups, e.g. ethylenediamine-tetra-acetic acid, iminodiacetic acids
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/36—Regeneration of waste pickling liquors

Definitions

  • the present invention relates to a process and system for purifying a contaminated caustic feed solution to recover spent hydroxide therefrom for reuse-
  • the present invention relates to a process and system that can be used for recovering spent NaOH or KOH and spent chelating agents that are used in cleaning in place (CIP) equipment in the food, biotechnological and pharmaceutical industries.
  • CIP cleaning in place
  • Cleaning in place of the production equipment in dairies and beverage plants is performed routinely at the end of each production cycle, and serves for maintaining the equipment in high hygienic state.
  • the cleaning of the equipment involves several steps: i) first rinse with water to remove suspended material; ii) second rinse with hot water for removing material that is loosely attached to the equipment and piping surfaces; iii) cleaning with hot alkaline cleaner for removing organic deposits; and iv) an additional rinse with water.
  • the alkaline step is followed with: v) water rinse; vi) acid rinse to dissolve mineral deposits, and finally vii) water rinse and sanitation.
  • caustic cleaners contain chelating agents such as ethylene diamine tetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) , which form soluble complexes with Ca " *" " ' " and Mg”*"* " ions and prevent a formation of insoluble precipitates.
  • EDTA ethylene diamine tetraacetic acid
  • NTA nitrilotriacetic acid
  • the use of the acid and the subsequent water cleaning step can be omitted, resulting in substantial savings of cleaning time and chemicals [D.A. Timperley and C.N.M. Smeulders, Unilever Research Laboratory, Journal of the Society of Dairy Technology, Vol. 40, No. 1, pp. 4-7 (February 1987); and D. A. Timperley and C.N.M. Smeulders, Unilever Research Laboratory, Journal of the Society of Dairy Technology, Vol. 41, No. 1 (February 1988)].
  • EDTA ethylene diamine te
  • FIG. 1 A typical flow sheet of the CIP process in the dairy or beverage plant is shown in Fig. 1 appended hereto.
  • the caustic cleaner is stored in a tank 1 having a volume of 2-30 m 3 , which is heated to a cleaning temperature of 50-85°C before the cleaning step.
  • the caustic solution is circulated by a circulation pump to the CIP users 2 such as tanks, piping, pasteurizers, evaporators, for a predetermined period of time. After completing the cleaning cycle with caustic cleaner, fresh water is introduced, displacing the caustic solution from the equipment.
  • the first fractions of caustic solution that are characterized with high NaOH concentration are recycled back to the storage tank 1 via a return line 5, while the diluted caustic stream is discharged to wastes through line 4.
  • the caustic concentration in tank 1 is maintained constant by adding make-up water 7 and make-up caustic solution 6 thereto. Most of these tasks are performed automatically by means of control equipment such as level meters, conductivity meters, pH meters and control valves (not shown).
  • the contaminated caustic cleaner still contains a high concentration of active caustic solution, and it can be reused three or four times. After these three or four reuse cycles, the caustic solution
  • SUBSTITUTESHEET(R ULE2e) cannot be reused again without further treatment, due to the accumulation of a heavy load of dispersed and soluble organic contaminants. At this point, the contents of the caustic tank are neutralized and discharged to waste. The frequency of discharge varies from once per day to once per week. As a result of the discharge, substantial quantities of valuable caustic and additives are lost, causing a substantial financial loss.
  • caustic cleaners contain different types of additives, which are used for improving the efficiency of the cleaning step.
  • Antifoams are added to eliminate foam formation by proteins; surfactants are added for improving permeability of the caustic into a solid cake and improving the effectiveness of cleaning; and chelating agents are added in order to form soluble complexes with Ca*"*" and Mg"*"* ions, thus preventing the formation of insoluble precipitates of CaCO a and Mg(OH) a .
  • EDTA and NTA are among the most powerful and therefore widely used chelating agents, though other additives such as gluconates and phosphonates, as well as other chelating and/or complexing agents, are also in common use.
  • examples of such components other than EDTA and NTA are methylene phosphonic acid, sodium heptogluconate, modified polyethoxylate alcohol, glucosides and organic polyelectrolyte anionic dispersants.
  • additional objectives of the present invention are methods and systems enabling the recovery and recycling of chelating agents such as EDTA and NTA, and, in general, of components such as organic polyelectrolytes, which are soluble in basic solutions but precipitate in acidic solutions.
  • a process for purifying a contaminated caustic feed solution to recover spent hydroxide and, optionally, chelating agents, therefrom for reuse comprising applying said feed solution at a superatmospheric pressure to the feed side of an alkali-resistant nanofiltration membrane, which is permeable to NaOH and KOH, while slightly or non-permeable to low molecular weight soluble organic compounds or organic ions having a molecular weight of at least 150, whereby purified caustic solution is passed across the membrane to the permeate side thereof.
  • the purified caustic solution is passed across the membrane to the permate side thereof, while all of the dispersed organic and mineral contaminants and most of the soluble organic contaminants, as well as chelating agents, co plexing agents, surfactants, antifoams and some divalent ion salts, are retained and concentrated on the feed side of the membrane.
  • the concentration of the caustic stream in the permeate is nearly identical to the concentration of the caustic in the contaminated feed stream, and its purity is adequate for use in the cleaning process.
  • a substantial reduction of caustic consumption in the factory can be achieved.
  • the caustic savings can reach 90-98% of the regular caustic consumption when such a membrane is not used.
  • the slightly permeable or non-permeable low molecular weight compounds in the concentrate retained on the feed side of the membrane comprise, at least in part, chelating agents, wherein said chelating agents are soluble in caustic conditions but precipitate under acidic conditions between pH 0 to 4.
  • the invention also provides a process further comprising adjusting the pH to an acid level by adding a mineral acid, wherein, after the chelating agent is precipitated, it is filtered from the solution, optionally washed, and then reused.
  • a mineral acid is HCL
  • the chelating agent may be ethylene diamine tetraacetic acid (EDTA) or nitrilotriacetic acid (NTA) , or a polyanionic compound containing carboxylic acid groups.
  • a further object of the invention is the removal from NaOH of carbonate ions that are formed in the caustic solution as a result of a chemical reaction between the atmospheric C0 2 gas and the caustic cleaner.
  • the alkali-stable nanofiltration membranes used in the present invention preferably remove carbonate ions and pass only the active caustic cleaner. This is an important feature, since in a recycling mode there is an expected accumulation of carbonate salts as a result of the above-mentioned chemical reaction, further resulting in a decrease of the cleaning potency of the caustic cleaner.
  • the nanofiltration membrane is used in the caustic recovery process, only the pure caustic, which is nearly free of carbonate salts, is recycled to the cleaning step.
  • EDTA When EDTA is used as a chelating agent, it is retained in the retentate loop, where all the other retained organic and mineral compounds are admixed. Because of its economic value, and also because it is becoming prohibited to discharge this compound into sewage, there are high economic and environmental interests in recovery of EDTA from the concentrate and its recycling as active component back to the holding tank.
  • Japanese Patents 63/190,694; 62/178,553; 63/297,348 and 62/292,748 claim a process for the recovery of EDTA from plating wastes. In their process, the pH of the waste stream is adjusted ⁇ 3 with acid, causing free EDTA to precipitate in crystal form.
  • German Patent 39 29 137 discloses the recovery of EDTA from electroplating wastes by protonating the spent EDTA by means of a bipolar membrane stack.
  • Japanese Patent 89/149,756 discloses a method for separating EDTA from the mother liquor in separation of rare earth elements.
  • the metal EDTA complex is treated with acid, to reduce the pH and precipitate 90% of the EDTA as solid crystals.
  • the supernatant is treated with an acid form of the cation exchange resin that adsorbs the remaining EDTA.
  • the present invention further provides a process as defined above, and further comprising effecting diafiltration of the concentrated feed solution retained on the feed side of the nanofiltration membrane with aqueous solution to decrease the base and salt concentration thereof, and then adjusting the pH to an acidic level whereby organic acetic acid type chelating agents and other chelating agents which precipitate under acidic conditions contained therein are precipitated and recovered for reuse.
  • the pH of said concentration feed is adjusted to between 0 and 4, and most preferred is- a level of between 1 and 3.
  • the invention also provides a system for purifying a contaminated caustic feed solution containing organic ⁇ cetic acid chelating agents and organic and mineral impurities, to recover spent hydroxide therefrom for reuse, comprising an alkali-resistant module equipped with an alkali-resistant nanofiltration membrane which is permeable- to NaOH and KOH while non-permeable to low molecular weight soluble compounds having a molecular weight of at least 150; means for circulating said feed solution at superatmospheric pressure to the feed side of said membrane; and means for recycling purified caustic solution from the permate side of said membrane for reuse.
  • said system further comprises means for constantly filtering dispersed compounds from concentrated feed solution, thus leaving said concentrate free from suspended matter; means for controlling the conductivity of said concentrate at a predetermined level; diafiltration means for effecting diafiltration of the concentrated feed solution retained on the feed side of said membrane; means for adjusting the pH of the concentrate to a predetermined level; means for filtering precipitated chelates and separating the., same from dissolved organic and mineral contaminants retained in said concentrated feed solution; and means for recycling purified caustic solution from the permeate side of said membrane into a further filtering means together with said filtered precipitated chelates.
  • Fig. 1 is a flow sheet of a standard cleaning in place process
  • Fig. 2 is a schematic diagram of a preferred process of the present invention.
  • tank 9 in the modified batch process a relatively large, fixed volume of solution or suspension, stored in tank 1, is continuously fed into a smaller tank 9 at such a rate that the level in tank 9 is kept constant until the major part of the volume has been removed from tank 1 (for example, 90%).
  • the concentrate is stored in tank 9.
  • tank 9 can be relatively small; for example, tank 9 may be one-tenth the size of tank 1.
  • the stream 8 from NaOH holding tank 1, containing caustic and organic contaminants, is continuously introduced into holding tank 9 of the membrane unit.
  • Stream 8 is first filtered at 10 and pumped by pump 11 into membrane module
  • the retentate stream 14 is recycled back to holding tank 9, while the permeate 15, free of contaminants, is returned to main holding tank 1 via a return pipe 16. All the contaminants, constituting suspended material, are - 11 -
  • the whole volume of the caustic tank 1 will be transferred into a large system tank 9 of the same volume.
  • the volume in tank 9 will decrease as a result of permeate that is removed in membrane module 12.
  • the concentration of retained species has increased proportionally.
  • the contents of tank 9 will be transferred via filter 10 to the precipitation tank 20, from which the EDTA will be recovered.
  • contaminated caustic soda from tank 1 will be continuously pumped into membrane module 12, thus splitting the feed stream into two: the filtered concentrate stream 14 containing EDTA and dissolved organics, and the pure caustic stream 15, which is recycled back to tank 1.
  • concentrate stream 14 is transferred directly to a precipitation tank 20 for the recovery of EDTA (not shown).
  • the above-described modified batch operation is the preferred mode for caustic recovery in CIP operations, because the membrane feed tank 9 can be one-tenth the volume of main caustic tank 1; compared to the batch and continuous modes, the modified batch mode is highly flexible and can be successfully applied, • even when the caustic solution composition varies and membrane fluxes change.
  • a further embodiment of the present invention aimed at recovery and recycling of EDTA, comprises the following steps:
  • Diafiltration water 17 is added to the membrane unit tank while removing the permeate through lines 15 and 28 into wastes, until the conductivity within tank 9, measured by meter 18, is as low as is needed for the subsequent precipitation. Clear liquid 19 is then transferred into precipitation tank 20, equipped with a pH measuring electrode 22, means 23 for adding acid, and agitator 21. The pH within tank 20 is adjusted to. the required level of a range of between 1-3, and the EDTA is left to precipitate.
  • the whole stream is then passed into filtration unit 24 which contains a suitable filter 25, which retains the precipitated EDTA and discharges the filtrate 27 with the contaminants. Subsequently, the caustic permeate 15 is directed into filter unit 24, causing the EDTA to dissolve and flow into holding tank 1 via piping 16.
  • the filtration units and filtration membranes used to filter the precipitated EDTA may be any of those well-known in the art.
  • microfilters from 0.1-20 microns, or filter screens, cloths, or nets may be used, all of which may be made from organic or inorganic materials, ceramics, or metal.
  • the actual filter units may be chosen from filter bags, rotary filters, deadend filters, filter presses, tubular, plate, or frame filters.
  • Example 1 exemplifies, the importance of using only base stable nanofiltration membranes, which will pass the base and retain the contaminants and EDTA.
  • permeate were collected.
  • the permeate was crystal clear and did not contain any colour or suspended material which was originally present in the feed solution.
  • the accumulated concentration of NaOH in the permeate at the end of the experiment was identical to that at the beginning, i.e., 2%.
  • the concentration of EDTA in the permeate was nearly zero at the end of the experiment, compared to «0.5% in the feed solution, indicating a rejection value to EDTA of more than 99%.
  • the concentration of EDTA in the concentrated feed solution was 4.99%.
  • step 5 the concentrate solution was removed from the cell into a beaker equipped with a magnetic stirrer and its pH was adjusted to pH ⁇ 3 by adding concentrated HC1. The solution was left at room temperature for about one hour while being stirred, following which the EDTA precipitate was filtered out on a Whatman No. 41 filter. The amount of EDTA on the filter paper was 0.765 g of H * EDTA, indicating that more than 97% of the EDTA was precipitated by this method. - 17 -
  • Example 3 was repeated, without the diafiltration and adjusting the EDTA concentrate solution to a pH of 1.0. In this mode, 98% of the EDTA was precipitated and collected on filter paper. The EDTA was reused in similar experiments, giving similar results.
  • This example concerns purification of a caustic stream and the recovery and reuse of EDTA from a CIP cleaning solution, using commercial cleaning additive SU-560, manufactured by Lever Industries.
  • Example 6 was repeated with the addition of 0.5% milk to the caustic /SU-560 solution. The results showed a clear permeate solution, with 0% rejection to NaOH and >90% recovery of EDTA. - 22 -

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Nanotechnology (AREA)
  • Water Supply & Treatment (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)

Abstract

Procédé de purification d'une solution (3) caustique contaminée alimentée en continu, afin de récupérer à partir de celle-ci, aux fins de réutilisation, l'hydroxyde épuisé ainsi que, le cas échéant, des agents de chélation, ledit procédé consistant à diriger, à une pression supérieure à la pression atmosphérique, ladite solution vers le côté d'admission d'une membrane (13) de nanofiltration perméable à NaOH et à KOH et légèrement perméable ou imperméable à des composés organiques solubles de bas poids moléculaire, celui-ci étant d'au moins 150, la solution (15) caustique purifiée passant ainsi à travers la membrane du côté de perméation de celle-ci.
PCT/EP1995/001277 1994-04-07 1995-04-07 Procede et systeme de purification d'une solution caustique contaminee alimentee en continu WO1995027681A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IL109249 1994-04-07
IL10924994A IL109249A0 (en) 1994-04-07 1994-04-07 Process and system for purifying a contaminated caustic feed solution

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WO1995027681A1 true WO1995027681A1 (fr) 1995-10-19

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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997023279A1 (fr) * 1995-12-23 1997-07-03 Krebs & Co. Ag Procede d'epuration d'un liquide pollue par des molecules filiformes
WO1997032000A2 (fr) * 1996-03-01 1997-09-04 Henkel-Ecolab Gmbh & Co. Ohg Nettoyant pour installations de l'industrie alimentaire, son utilisation et procede de nettoyage de ces installations
WO1998041672A1 (fr) * 1997-03-14 1998-09-24 Daimlerchrysler Ag Procede et dispositif pour l'exploitation de bains de fraisage
FR2794032A1 (fr) * 1999-05-27 2000-12-01 Univ Claude Bernard Lyon Procede pour separer en milieu aqueux des lanthanides et/ou des actinides par complexation-nanofiltration, et nouveaux complexants mis en oeuvre dans ce procede
WO2004014805A1 (fr) * 2002-08-13 2004-02-19 Veolia Water Uk Plc Ameliorations apportees au traitement de l'eau
US6896810B2 (en) * 2002-08-02 2005-05-24 Rayonier Products And Financial Services Company Process for producing alkaline treated cellulosic fibers
EP1726353A1 (fr) * 2005-05-25 2006-11-29 Johnson Diversey, Inc. Filtration membranaire d'un produit
ES2299317A1 (es) * 2005-11-08 2008-05-16 Corporacion Alimentaria Peñasanta, S.A. Procedimiento para la recuperacion de detergentes alcalinos de fase unica utilizados en instalaciones industriales de limpieza in situ.
US7575687B2 (en) 2005-08-16 2009-08-18 Ge Osmonics, Inc. Membranes and methods useful for caustic applications
US7909179B2 (en) 2005-08-16 2011-03-22 Ge Osmonics, Inc. Modified polyamide matrices and methods for their preparation
CN111533294A (zh) * 2019-08-29 2020-08-14 缙云县智源企业事务代理有限公司 一种化工使用的退浆回收及废液收集一体化装置

Citations (1)

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Publication number Priority date Publication date Assignee Title
JPS59222292A (ja) * 1983-04-27 1984-12-13 Ebara Infilco Co Ltd エチレンジアミン四酢酸を含む化学洗浄廃液の処理方法

Patent Citations (1)

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Publication number Priority date Publication date Assignee Title
JPS59222292A (ja) * 1983-04-27 1984-12-13 Ebara Infilco Co Ltd エチレンジアミン四酢酸を含む化学洗浄廃液の処理方法

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
D. A. TIMPERLEY, C. N. M. SMEULDERS: "Cleaning of dairy HTST plate heat exchangers: comparison of single- and two-stage procedures", JOURNAL OF THE SOCIETY OF DAIRY TECHNOLOGY, vol. 40, no. 1, GB, pages 4 - 7 *
DATABASE WPI Week 8505, Derwent World Patents Index; AN 85-027763 *
R. DANZIGER: "Ein Membrantrennverfahren zur NaOH-Rückgewinnung", FETT WISSENSCHAFT TECHNOLOGIE- FAT SCIENCE TECHNOLOGY, vol. 94, no. 10, LEINFELDEN ECHTERDINGEN DE, pages 401 - 403 *

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997023279A1 (fr) * 1995-12-23 1997-07-03 Krebs & Co. Ag Procede d'epuration d'un liquide pollue par des molecules filiformes
US6204231B1 (en) 1996-03-01 2001-03-20 Henkel Kommandigesellschaft Auf Aktien Cleaning agent for food-industry facilities, its use and method of cleaning such facilities using the agent
WO1997032000A2 (fr) * 1996-03-01 1997-09-04 Henkel-Ecolab Gmbh & Co. Ohg Nettoyant pour installations de l'industrie alimentaire, son utilisation et procede de nettoyage de ces installations
WO1997032000A3 (fr) * 1996-03-01 1997-12-11 Henkel Ecolab Gmbh & Co Ohg Nettoyant pour installations de l'industrie alimentaire, son utilisation et procede de nettoyage de ces installations
AU714812B2 (en) * 1996-03-01 2000-01-13 Henkel-Ecolab Gmbh & Co. Ohg A cleaning formulation for equipment used in the food industry, its use and a process for cleaning such equipment
US6454958B1 (en) 1997-03-14 2002-09-24 Daimlerchrysler Ag Method and device for operating etching baths
WO1998041672A1 (fr) * 1997-03-14 1998-09-24 Daimlerchrysler Ag Procede et dispositif pour l'exploitation de bains de fraisage
FR2794032A1 (fr) * 1999-05-27 2000-12-01 Univ Claude Bernard Lyon Procede pour separer en milieu aqueux des lanthanides et/ou des actinides par complexation-nanofiltration, et nouveaux complexants mis en oeuvre dans ce procede
WO2000073521A1 (fr) * 1999-05-27 2000-12-07 Universite Claude Bernard Lyon I Procede pour separer en milieu aqueux des lanthanides et/ou des actinides par complexation-nanofiltration, et nouveaux complexants mis en oeuvre dans ce procede
US6843917B1 (en) 1999-05-27 2005-01-18 Universite Claude Bernard Lyon 1 Method for separating in an aqueous medium lanthanides and/or actinides by combined complexing-nanofiltration, and novel complexing agents therefor
US6896810B2 (en) * 2002-08-02 2005-05-24 Rayonier Products And Financial Services Company Process for producing alkaline treated cellulosic fibers
WO2004014805A1 (fr) * 2002-08-13 2004-02-19 Veolia Water Uk Plc Ameliorations apportees au traitement de l'eau
GB2407316A (en) * 2002-08-13 2005-04-27 Veolia Water Uk Plc Improvements relating to water treatment
EP1726353A1 (fr) * 2005-05-25 2006-11-29 Johnson Diversey, Inc. Filtration membranaire d'un produit
WO2006127579A3 (fr) * 2005-05-25 2007-04-12 Johnson Diversey Inc Filtration membranaire d'un produit
US7575687B2 (en) 2005-08-16 2009-08-18 Ge Osmonics, Inc. Membranes and methods useful for caustic applications
US7909179B2 (en) 2005-08-16 2011-03-22 Ge Osmonics, Inc. Modified polyamide matrices and methods for their preparation
ES2299317A1 (es) * 2005-11-08 2008-05-16 Corporacion Alimentaria Peñasanta, S.A. Procedimiento para la recuperacion de detergentes alcalinos de fase unica utilizados en instalaciones industriales de limpieza in situ.
CN111533294A (zh) * 2019-08-29 2020-08-14 缙云县智源企业事务代理有限公司 一种化工使用的退浆回收及废液收集一体化装置

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AU1625895A (en) 1995-10-19

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