WO1990002708A1 - Procede de purification de milieu aqueux residuel - Google Patents

Procede de purification de milieu aqueux residuel Download PDF

Info

Publication number
WO1990002708A1
WO1990002708A1 PCT/FI1989/000166 FI8900166W WO9002708A1 WO 1990002708 A1 WO1990002708 A1 WO 1990002708A1 FI 8900166 W FI8900166 W FI 8900166W WO 9002708 A1 WO9002708 A1 WO 9002708A1
Authority
WO
WIPO (PCT)
Prior art keywords
chitosan
aqueous medium
pollutants
range
microcrystalline chitosan
Prior art date
Application number
PCT/FI1989/000166
Other languages
English (en)
Inventor
Henryk Struszczyk
Olli KIVEKÄS
Johan J. Lindberg
Marja-Liisa Riekkola
Kari Holopainen
Original Assignee
Firextra Oy
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 Firextra Oy filed Critical Firextra Oy
Publication of WO1990002708A1 publication Critical patent/WO1990002708A1/fr

Links

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
    • C02F1/28—Treatment of water, waste water, or sewage by sorption
    • C02F1/286—Treatment of water, waste water, or sewage by sorption using natural organic sorbents or derivatives thereof
    • 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
    • C02F1/5263—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using natural chemical compounds

Definitions

  • This invention relates a method for purification of waste aqueous medium using macrocrystalline chitosan.
  • Chitosan is partially or totally deacetylated chitin which is also known by its chemical name of poly (N- acetylglucosamine). Chitin forms the hard shell of Crustacea and insects as well as the cell walls of fungi. Chitosan is known by its chemical name of poly (2-deoxy-2-aminoglucose). The chitin and chitosan manufacture as well as their properties are described in "Chitin", Pergamon Press, New York, 1977. Microcrystalline chitosan is a specific physical- chemical form of standard chitosan manufactured by special aggregation system. The product according to this method, described in Journal fo Applied Polymer Science, vol. 33 , p.
  • Microcrystalline chitosan shows a water retention value (WRV) in a powder form within a range of 200-500% and in a dispersion form within a range of 500-5000%, the average molecular weight within a range of 10 4 -10 6 , deacetylation degree not less than 30% as well as Z-potential in a pH 7,0 ranging from -2,0 to +10,0.
  • WRV water retention value
  • Standard chitosan working as ion- exchanger, sorption and chelating material is able to remove from solution several ions, such as mercury, lead, zinc, copper, chromium, plutonium, uranium, as well as organic substances as dyes form dye processing effluents, tannin from wine and other beverages and other organic pollutants.
  • the standard chitosan is used in industrial pollutant removal, treatment of chemical wastes, sea mining and other activities.
  • the standard chitosan in well-known methods is recommended to be applied in a form of chitosan salts as the self-dissolving chitosan as well as direct addition of chitosan to dilute organic acid and then added to waste water.
  • US Patent 3533940 discloses a method for treating the aqueous medium with standard chitosan and derivatives of chitin to remove an impurity by adding dissolved chitosan or derivatives of chitin in a form of solution to generate the agglomerates comprising said impurity and said chitosan.
  • Yoshinari and Subramanian in monography “Environmental Biogeochemistry; vol. 2. Mental Transfer and Ecological Mass Balance", Ann Arbor Science Publ., Ann Arbor, 1976, disclose that collection in a form of acidic solution as well as flakes or powder depend on several factors the most important of which are polymer grain size, temperature, speed and mode of stirring, presence of other ions suitable for collection, oxidation number of ion and pH of solution.
  • the well-known methods require the use of several complicated operations for preparation of chitosan solution as well as chitosan powder and make impossible removing of chitosan used from water.
  • the effective pH region for chelating of metal ions ranges from 4 to 6.5-7,0 and the chitosan solution is totally ineffective in pH above 7,0.
  • the chitosan flakes and powder are distinguished by their low value of intrinsic surface related to the sorption, chelating, as well as ion-exchange effectivity.
  • the object of this invention is to provide the purification of waste aqueous medium by microcrystalline chitosan, especially in a gel-like dispersion, applying this microcrystalline polymer directly to a waste aqueous medium or filtering the medium through microcrystalline polymer, as well as by generation of microcrystalline chitosan directly in waste aqueous medium to remove the pollutants.
  • a microcrystalline chitosan is introduced into the waste aqueous medium containing the pollutants and characterized by reaction with pH not lower than 7,0, especially in chitosan concentration within a range of 0,1-100 g/l, preferably 1-20 g/l, and next mixed by a time not shorter than 1 minute, preferably 5 minutes to 1 hour, in a temperature range of 4- 90°C, preferably 10-40°C, and then the microcrystalline chitosan containing bonded pollutants, such as metal ions, is removed from the solution using filtration, sedimentation, centrifugation and other systems.
  • the microcrystalline chitosan in a gel-like dispersion or powder form is used as the matrix for removing of the pollutants, such as metal ions, from waste aqueous medium by filtration or column systems.
  • the microcrystalline chitosan used for purification of the waste aqueous medium and removing of the pollutants, such as metal ions, in a gel-like dispersion preferably in water has especially a water retention value (WRV) within a range of 500- 5000%, deacetylation degree not less than 30%, average molecural weight within a range of 10 4 to 10 6 , Z- potential at pH 7,0 within a range of -2,0 to +10,0 as well as a particle dimension preferably within a range of 0,01 to 200 ⁇ m, and in a powder form it has especially a water retention value within a range of 200-500%, deacetylation degree not less than 30%, average molecular weight within a range of 10 4 to 10 6 , Z-potential at pH 7,0 within a range of 0 to +10,0 as well as a particle dimension preferably within a range of 0,1 to 100 ⁇ m.
  • WRV water retention value
  • a microcrystalline chitosan used for purification of waste aqueous medium containing pollutants, such as metal ions is formed directly in the purified aqueous medium by introduction of standard chitosan dissolved in dilute organic acids such as acetic or citric acid, in concentration preferably within a range of 0,05 to 2,0%, especially 0,5 to 1,0% into waste aqueous medium characterized by pH not lower than 7,0, preferably 8,0 to 12,0, using intensive stirring for e.g.
  • microcrystalline chitosan concentration of preferably 0,1-100 g/l, especially 1-20 g/l, the chitosan formed being in a form of gel-like dispersion having a particle diameter within a range of 0,01 to 50 ⁇ m and containing at the same time bonded pollutants, such as metal ions.
  • the microcrystalline chitosan dispersion containing pollutants is removed from aqueous medium by filtration, sedimentation or centrifugation as well as other methods.
  • standard chitosan especially in a form of solution in dilute organic acids such as acetic or citric, preferably in concentration of 0,01 to 2,0%
  • the waste aqueous medium containing pollutants, such as metal ions is introduced into the waste aqueous medium containing pollutants, such as metal ions, the medium being characterized by acidic reaction in a range of pH less than 7,0, preferably 1-5, to obtain a concentration of polymer within a range of 0,1-100 g/l, especially 0,5-20 g/l, then the neutralization process by alkaline solution, especially sodium hydroxide or potassium hydroxide, connected with intensive stirring for e.g.
  • microcrystalline chitosan formation in concentration of preferably 0,1 to 100 g/l, especially 0,5-20 g/l, in a form of gel-like dispersion with a particle diameter within a range of 0,01 to 50 ⁇ m containing at the same time bonded pollutants, such as metal ions.
  • the microcrystalline chitosan dispersion containing pollutants is removed from aqueous medium by filtration, sedimentation, centrifugation and other methods.
  • the well-known purification systems for waste aqueous medium containing pollutants e.g.
  • chitosan used in a form of solution in dilute acids or flakes and powder.
  • the chitosan acts in these systems as: ion-exchanger, sorption matrix and chelating polymers.
  • the standard chitosan acts with different effectivity according to its form.
  • the dissolved chitosan acts only as chelating polymer and ion-exchanger, whereas in a solid phase in a form of flakes or powder this polymer is working as a sorption matrix and ion-exchanger. Therefore the standard chitosan is not able to act with total effectivity in contrast to the microcrystalline chitosan.
  • Microcrystalline chitosan existing in a form of gellike dispersion characterized by highly developed intrinsic surface in connexion to formation of high- energy hydrogen bonds, having in its powder form highly developed intrinsic surface as well, can act by three different directions of bonding of pollutants, such as metal ions, at the same time, namely: sorption, ion-exhange and chelating.
  • pollutants such as metal ions
  • the main reason of higher effectivity for purification of waste aqueous medium using microcrystalline chitosan is related to its specific super-molecular structure and behaviour, mainly to its intrinsic surface, developed capillary system, crystallinity, ability for chelating and formation of hydrogen bonds and ability to formation of swelled aggregates.
  • the purification method in accordance with the invention shows high effectivity in the region from acidic to alkaline reaction whereas standard chitosan acts mainly in the acidic region only.
  • the special effectivity of microcrystalline chitosan for purification of pollutions and metal ions from waste aqueous medium is observed in a case of alkaline reaction with a pH higher than 7,0, especially within a range of 8,0-12,0.
  • Another important advantage of the invention is related to a special high effectivity of microcrystalline chitosan used for purification of waste aqueous medium from iron ions, wherein this microcrystalline polymer shows reduction of these ions about 100%, whereas in this case standard chitosan acts with effectivity not higher than 50 to 70% in best conditions.
  • microcrystalline chitosan in this application acts very effectively with possibility to obtain, for example, a content of iron ions in water about 0,5 ppm, zinc ions about 0,1 ppm or copper ions less than 0,1 ppm, whereas the standard is not so effective.
  • microcrystalline chitosan for purification of waste water containing zinc ions and having a pH of 7,4-8,0 allows to obtain after 15 minutes the concentration of zinc ions on a level of 0,4 ppm, whereas standard chitosan applied in this same concentration and in a pH of 2,1 gives the zinc content of 5,0 ppm.
  • the standard chitosan applied in this same waste water having a pH of 7,4-8,0 as flakes or powder is characterized by a very low activity.
  • the method of the waste aqueous medium purification by the application of microcrystalline chitosan, especially in a form of gel-like dispersion, in accordance with the invention allows to remove the dispersed and dissolved inorganic and organic pollutants in a wide range of pH depending on the system of the invention used.
  • the method in accordance to the invention allows to purify waste aqueous medium having a pH not lower than 7,0 (neutral to alkaline) by introduction of microcrystalline chitosan, especially in a gel-like form characterized by developed intrinsic surface, which binds the pollutants by sorption, chelating and ion-exhange.
  • the powdered form of microcrystalline chitosan is also preferred in this system.
  • the microcrystalline chitosan, both in a gel-like dispersion and powder form is able to act in discussed system as a matrix in filtration or in a column method.
  • the method in accordance with the invention allows also to conduct a purification of waste aqueous medium having a pH not lower than 7,0, preferably 8,0-12,0, using microcrystalline chitosan formed directly in this medium by neutralization and precipitation from a standard chitosan solution.
  • the microcrystalline chitosan formed by method of "in statu nascendi" used according to the invention is characterized by high intrinsic surface as well as effectivity of sorption, chelating and ion-exchange.
  • the method in accordance to the invention allows also to purify the waste aqueous medium having a pH lower than 7,0 (acidic) using a standard chitosan solution introduce to the above medium.
  • the microcrystalline chitosan combining the pollutants is formed by neutralization and intensive stirring of the above medium containing dissolved chitosan using an alkaline solution to obtain a pH within a range of 7,5-9,0.
  • the formed microcrystalline chitosan acts by sorption, chelation and ion-exchange to bind pollutants from the aqueous medium.
  • the method in accordance with the invention is uncommonly simple and easy for practical realization in comparison to well-known methods, giving the high effectivity of a purification process by simple technological operations as a result.
  • certain advantages of invention are concerned with the purification of waste aqueous medium containing also organic pollutants such as dyes, dispersed proteins etc., as well as inorganic pollutants as dispersed substances.
  • organic pollutants such as dyes, dispersed proteins etc.
  • inorganic pollutants as dispersed substances.
  • the microcrystalline chitosan based mainly on its sorption behaviour, is able to combine with organic as well as inorganic substances for their removal from an aqueous medium.
  • Waste aqueous medium containing organic and inorganic pollutants was used for its purification by microcrystalline chitosan.
  • inorganic pollutants metal ions, such as zinc, iron, manganese, copper as well as other ions, were removed by microcrystalline chitosan.
  • other inorganic pollutants were clarified off by microcrystalline chitosan.
  • organic pollutants the dyes appearing in the galvanisation wastes for example were removed by microcrystalline chitosan.
  • microcrystalline chitosan PMCChl characterized by a polymer content of 4.55 wt%, a deacetylation degree of 78.8%, a water retention value of 870% and an average degree of polymerization of 4,2 x 10 -5 in concentration of 8.22 weight parts of MCCh per 1000 volume parts of pre-purified waste water using stirring for a suitable time.
  • the results of the purification process by the microcrystalline chitosan are presented in table 1.
  • the pre-purified water was characterized by zinc content of 38.05 ppm and pH 7.5. This type of water was treated by different amounts of microcrystalline chitosan characterized by properties shown in Example 1, by stirring the obtained dispersion for 15 minutes. The results of purification process by microcrystalline chitosan are presented in Table 2. Table 2. Effect of microcrystalline chitosan concentration on the zinc removal.
  • Example 4 1000 weight parts of pre-purified waste water containing zinc characterized by properties shown in Example 4 was treated by microcrystalline chitosan dispersion with properties presented in Example 1. Then the microcrystalline chitosan with bonded zinc was removed by filtration. The data are presented in Table 5. Table 5 . Purification of waste water by microcrystalline chitosan dispersion.
  • microcrystalline chitosan dispersion acts with a higher effectivity than the powder form of this microcrystalline polymer.
  • the purification process by a dispersion of microcrystalline chitosan characterized by a polymer content of 2.55%, a deacetylation degree of 79%, an average molecular weight of 4,08 x 10 5 and a water retention value WRV of 1158% was made using a stirring process.
  • the concentration of microcrystalline chitosan in the water to be purified was equal to 9.5 g/l. After 15 minutes of purification the zinc content was 55 mg/l and iron content 1.3 mg/l, then after next 15 minutes of stirring 51.5 mg/l and 1.1 mg/l respectively. The purified water obtained was colourless.
  • Example 10 500 volume parts of liquid waste from a galvanizing process characterized by properties presented in Example 8 was treated by a 10 wt% sodium hydroxide solution on stirring for 30 minutes to obtain a pH of 9.5. After the sedimentation and filtration of the precipitated solids the residual liquid phase was characterized by a zinc content of 73 ppm and an iron content of 1500 ppm, and it was still light red-green. 450 volume parts of this pre-purified waste water was used as the coagulation and precipitation bath for microcrystalline chitosan formation process, using 84 weight parts of standard chitosan solutions in 4% aqueous acetic acid containing 1 wt% of polymer, employing intensive stirring at 500 r.p.m. for 19 minutes at a temperature of 25°C. After sedimentation and filtration of the obtained microcrystalline chitosan bonded with metal ions and other pollutions, the colourless purified water contained 10 ppm of zinc and 1.25 ppm of iron.
  • Example 10 500 volume parts of liquid
  • 100 weight parts of waste water left after dyeing of viscose fibres by the dyestuff "Solophenylblau AGFL" contained 0.4 g of dye/l.
  • the amount was introduced to filtration at room temperature in a column system containing 50 weight parts of microcrystalline chitosan dispersion with properties as in Example 1. After filtration process the colourless water contained not more than 1% of the initial amount of dye.

Landscapes

  • 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)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Polysaccharides And Polysaccharide Derivatives (AREA)
  • Separation Of Suspended Particles By Flocculating Agents (AREA)

Abstract

L'invention concerne un procédé de purification de milieu aqueux résiduel contenant des agents polluants inorganiques et organiques dispersés et dissous, tels que des colorants, des protéines et des ions métalliques, par exemple du zinc, du cuivre, du fer et des ions de manganèse, à l'aide de chitosan lors de la purification. Le chitosan utilisé est du chitosan microcristallin notamment sous forme d'une dispersion analogue à un gel permettant de lier les agents polluants et il est mis en contact avec les résidus directement à l'état préfabriqué, ou il est produit dans le milieu aqueux résiduel.
PCT/FI1989/000166 1988-09-05 1989-09-05 Procede de purification de milieu aqueux residuel WO1990002708A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI884074A FI884074A (fi) 1988-09-05 1988-09-05 Foerfarande foer rening av avloppsvatten.
FI884074 1988-09-05

Publications (1)

Publication Number Publication Date
WO1990002708A1 true WO1990002708A1 (fr) 1990-03-22

Family

ID=8526998

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI1989/000166 WO1990002708A1 (fr) 1988-09-05 1989-09-05 Procede de purification de milieu aqueux residuel

Country Status (3)

Country Link
AU (1) AU4197889A (fr)
FI (1) FI884074A (fr)
WO (1) WO1990002708A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5336415A (en) * 1993-02-10 1994-08-09 Vanson L.P. Removing polyvalent metals from aqueous waste streams with chitosan and halogenating agents
US5393435A (en) * 1993-09-17 1995-02-28 Vanson L.P. Removal of organic contaminants from aqueous media
GB2310205A (en) * 1996-02-15 1997-08-20 Commissariat Energie Atomique Separating metals from solution using chitosan
WO2004071961A2 (fr) * 2003-02-13 2004-08-26 White, Duncan, Rohan Dispositif et procede de conversion d'eau

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3533940A (en) * 1967-06-02 1970-10-13 Quintin P Peniston Method for treating an aqueous medium with chitosan and derivatives of chitin to remove an impurity
US3635818A (en) * 1968-12-06 1972-01-18 Maria Gertrude Muzzarelli Chitin and chitosan as chromatographic supports and adsorbents for collection of metal ions from organic and aqueous solutions and sea water
PL125995B2 (en) * 1981-02-27 1983-06-30 Process for preparing chitosan of enlarged internal surface
EP0212688A2 (fr) * 1985-06-21 1987-03-04 Consiglio Nazionale Delle Ricerche Glycanes substitués et réticulés, procédé et pour leur préparation et leur utilisation
FI77681B (fi) * 1986-08-18 1988-12-30 Firextra Oy Kitosanprodukter, i synnerhet filmer, och foerfarande foer deras framstaellning.

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3533940A (en) * 1967-06-02 1970-10-13 Quintin P Peniston Method for treating an aqueous medium with chitosan and derivatives of chitin to remove an impurity
US3635818A (en) * 1968-12-06 1972-01-18 Maria Gertrude Muzzarelli Chitin and chitosan as chromatographic supports and adsorbents for collection of metal ions from organic and aqueous solutions and sea water
PL125995B2 (en) * 1981-02-27 1983-06-30 Process for preparing chitosan of enlarged internal surface
EP0212688A2 (fr) * 1985-06-21 1987-03-04 Consiglio Nazionale Delle Ricerche Glycanes substitués et réticulés, procédé et pour leur préparation et leur utilisation
FI77681B (fi) * 1986-08-18 1988-12-30 Firextra Oy Kitosanprodukter, i synnerhet filmer, och foerfarande foer deras framstaellning.

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
CHEMICAL ABSTRACTS, Volume 100, 1984, (Columbus, Ohio, US), MUZZARELLI et al.: "Chelating derivatives of chitosan obtained by reaction with ascorbic acid", see page 111, abstract 105446m, & Carbohydr. Polym. 1984, 4(2), 137-51. *
CHEMICAL ABSTRACTS, Volume 107, 1987, (Columbus, Ohio, US), MUZZARELLI et al.: "Metal absorption by modified chitins", see page 724, abstract 97027c, & Spec. Publ. - R. Soc. Chem. 1986, 61(), 44-57. *
CHEMICAL ABSTRACTS, Volume 109, 1988, (Columbus, Ohio, US), see page 111. abstract 233068n; & JP,A,63 182 304 (Microcrystalline chitosan and manufacture), 1988. *
CHEMICAL ABSTRACTS, Volume 93, 1980, (Columbus, Ohio, US), MUZZARELLI et al.: "Chelating, film-forming, and coagulating ability of the chitosan-glucan complex from Aspergillus niger industrial wastes", see page 300, abstract 137329d, & Biotechnol. Bioeng. 1980, 22(4), 885-96. *
CHEMICAL ABSTRACTS, Volume 98, 1983, (Columbus, Ohio, US), R. MUZZARELLI et al.: "The Chelating ability of chitinous materials from Aspergillus niger, Streptomyces, Mucor rouxii Phycomyces blakesleeanus, and Choanephora cucurbitarum", see page 202, abstract 7822b, & Chitin Chitosan Proceeding Int. Conf. 1982, 2, 183-6. *
R.A.A. MUZZARELLI, "Natural Chelating Polymers", 1973, Pergamon Press, Oxford. *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5336415A (en) * 1993-02-10 1994-08-09 Vanson L.P. Removing polyvalent metals from aqueous waste streams with chitosan and halogenating agents
WO1994018125A1 (fr) * 1993-02-10 1994-08-18 Vanson L.P. Elimination de metaux polyvalents de courants aqueux de rebut a l'aide de chitosan et d'agents d'halogenation
US5393435A (en) * 1993-09-17 1995-02-28 Vanson L.P. Removal of organic contaminants from aqueous media
GB2310205A (en) * 1996-02-15 1997-08-20 Commissariat Energie Atomique Separating metals from solution using chitosan
GB2310205B (en) * 1996-02-15 2000-03-01 Commissariat Energie Atomique Method of separating at least one metal present in a solution by fixation onto a chitosane
WO2004071961A2 (fr) * 2003-02-13 2004-08-26 White, Duncan, Rohan Dispositif et procede de conversion d'eau
WO2004071961A3 (fr) * 2003-02-13 2004-12-23 Ehud Roffman Dispositif et procede de conversion d'eau
US7311829B2 (en) 2003-02-13 2007-12-25 H2Q Water Industries, Ltd. Water conversion device

Also Published As

Publication number Publication date
FI884074A (fi) 1990-03-06
FI884074A0 (fi) 1988-09-05
AU4197889A (en) 1990-04-02

Similar Documents

Publication Publication Date Title
Yang et al. A review on chitosan-based flocculants and their applications in water treatment
Crini et al. Application of chitosan, a natural aminopolysaccharide, for dye removal from aqueous solutions by adsorption processes using batch studies: A review of recent literature
CA2145939C (fr) Methode pour le traitement d'effluents de residus industriels a l'aide de floculants naturels
CN109319908A (zh) 改性壳聚糖-海藻酸钠复合絮凝剂的制备方法及其产品和应用
JPH11114313A (ja) 凝集剤及びこれを用いた凝集方法
BARBUSIŃSKI et al. The use of chitosan for removing selected pollutants from water and wastewater–short review
Sudha et al. Marine carbohydrates of wastewater treatment
Sudha et al. Applications of chitin/chitosan and its derivatives as adsorbents, coagulants and flocculants
CN108359103A (zh) 一种疏水改性壳聚糖絮凝剂及其制备方法和应用
CN105217765B (zh) 一种复合高分子絮凝剂及其制备方法
WO1990002708A1 (fr) Procede de purification de milieu aqueux residuel
JP2933627B2 (ja) 汚泥の脱水方法
JPS6215000A (ja) 下水スラツジの脱水方法
JPS62289300A (ja) 汚泥脱水剤
CN110040831A (zh) 一种海藻酸钠-聚甲基丙烯酰氧乙基三甲基氯化铵有机絮凝剂的制备方法
CN106006890A (zh) 一种壳聚糖混凝剂的制备方法
JP3071364B2 (ja) 含水ゲルの製造方法、重金属イオン吸着剤、色素吸着剤、微生物担体および酵素固定用担体
WO1995033690A1 (fr) Extraction du phosphate de milieu aqueux
US3830736A (en) Water clarification
CN117164764B (zh) 一种化学键链接的杂合天然高分子污泥调理剂及其制备方法与应用
Tsaneva et al. Evaluation of Adsorption Capacity of Chitosan-Citral Schiff Base for Wastewater Pre-Treatment in Dairy Industries.
JP2000140509A (ja) 新規な凝集剤とそれを用いる汚泥処理方法
Jadhav et al. Advancement of chitosan-based adsorbents for enhanced and selective adsorption performance in water/wastewater treatment
CN110104747A (zh) 一种用于柔性版印刷水墨废水处理的复合絮凝药粉及其应用
JPH11114314A (ja) 凝集剤及びこれを用いた凝集方法

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AT AU BB BG BR CH DE DK FI GB HU JP KP KR LK LU MC MG MW NL NO RO SD SE SU US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE BF BJ CF CG CH CM DE FR GA GB IT LU ML MR NL SE SN TD TG

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642