EP0071810B1 - Removal of metal ions from aqueous medium using a cation-exchange resin having water-insoluble compound dispersed therein - Google Patents

Removal of metal ions from aqueous medium using a cation-exchange resin having water-insoluble compound dispersed therein Download PDF

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Publication number
EP0071810B1
EP0071810B1 EP82106489A EP82106489A EP0071810B1 EP 0071810 B1 EP0071810 B1 EP 0071810B1 EP 82106489 A EP82106489 A EP 82106489A EP 82106489 A EP82106489 A EP 82106489A EP 0071810 B1 EP0071810 B1 EP 0071810B1
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EP
European Patent Office
Prior art keywords
water
aqueous medium
particles
metal ions
metal
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Expired
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EP82106489A
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German (de)
English (en)
French (fr)
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EP0071810A1 (en
Inventor
Melvin Jay Hatch
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Dow Chemical Co
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Dow Chemical Co
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    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
    • G21F9/00—Treating radioactively contaminated material; Decontamination arrangements therefor
    • G21F9/04—Treating liquids
    • G21F9/06—Processing
    • G21F9/12—Processing by absorption; by adsorption; by ion-exchange

Definitions

  • This invention relates to water-insoluble, hydrophilic cation-exchange resins that can remove metal ions, such as radium ions from an aqueous medium.
  • aqueous streams containing metal ions In many industries that employ aqueous streams containing metal ions, it is necessary to remove such ions from such streams because such metal ions are valuable and/or extremely toxic. Exemplary industries are those employing aqueous streams containing radioactive metal ions such as radium, e.g., industries using atomic reactors, hospitals, municipalities, scientific laboratories and industries engaged in mining of valuable metals.
  • aqueous liquids containing low levels of radionuclides such as uranium and radium.
  • the composition of this aqueous liquid may be either acidic or alkaline, depending upon (1) the particular uranium material being mined, (2) the other mineral present in the host formation, and (3) the chemical composition of the ground water itself.
  • the undesired radioactive metals are often absorbed on slimes which are then passed to tailings impoundment areas. Unfortunately, water contacting such areas becomes contaminated with such radioactive metals and must be processed to remove the radioactive metals before discharge.
  • GR-A-769121 describes a method for removal of metals from an aqueous solution by contacting the aqueous solution with a conventional ion exchange resin in the barium form (i.e. by attaching the Ba" ions to the pendant sulfonic groups thus forming BaS0 4 at the surface of the resin) and converting this resin into the alternate metal form.
  • the present invention is a finely divided particulate for removing metal ions from an aqueous medium, the particles of the particulate comprising a porous matrix of a water-insoluble, hydrophilic, normally solid cation exchange resin, characterized in that a water-insoluble inorganic salt of a chemically similar metal capable of removing the metal ions from an aqueous medium dispersed within said matrix, said particles being permeable to the passage of the metal ions from the aqueous medium under conditions such that a substantial portion of said metal ions are removed from the aqueous medium and retained in the matrix when the particles are contacted with the aqueous medium.
  • the present invention is also a process for preparing an adsorptive cation exchange resin for removing and retaining metal ions from an aqueous medium characterized by contacting. finely divided particles of a water-insoluble, hydrophilic polymer bearing pendant anionic moieties in the interior regions of the particles with an aqueous solution of a compound of a chemically similar metal under conditions such that a salt of the chemically similar metal and a desired portion of the anionic moieties in said interior regions are formed and contacting the resulting metal salt form of the particles with an inorganic acid under conditions such that (a) the acid invades said interior regions and reacts with the chemically similar metal salt to form a water-insoluble compound capable of removing the desired metal ion from an aqueous medium and (b) the resulting particles containing the water-insoluble compound are permeable to the transport of metal ions into the interior regions of the particles.
  • this invention is a method for removing metal ions from an aqueous liquid which comprises contacting the particulate described above with the aqueous liquid under conditions such that the metal ions pass into the interior regions of the particles of the resin and are thereby removed from the aqueous liquid.
  • the adsorptive resins of the present invention are much more efficient in removing specific metal ions from aqueous medium than the particulate adsorbents of the prior art.
  • “more efficient” is meant that the resins have the capacity to remove and retain greater quantities of specific metal ions and can reduce the concentration of such specific metal ions in the aqueous media to lower levels than can the prior art absorbents.
  • the absorptive resins of the present invention are particularly useful in removing radioactive divalent radium ions from aqueous effluents of uranium mining operations, especially those containing rather low levels, e.g., 2-1000 picocurie/liter, of the radium ions.
  • Other uses for the resins of the present invention include those requiring the removal of radium from leach solutions of various mining processes, as well as from uranium tailing streams, and a wide variety of applications that require dense resins for the removal of cations from aqueous liquids. Examples of such applications are the processing of dense solutions e.g., concentrated sugar solutions and salt solutions, by conventional downflow or upflow techniques. In addition, by using fluidized bed ion-exchange procedures with these dense resins, a more efficient operation can be achieved.
  • the hydrophilic polymer forming the porous matrix of the particulate is suitably any normally solid, water-insoluble organic polymer bearing a sufficient number of pendant anionic moieties to enable the polymer to exchange cations from an aqueous medium.
  • the backbone of-the polymer is not particularly critical as long as the resultant polymer containing the anionic moieties is water-insoluble. Accordingly, the polymer may be phenolic, polyethylenic including styrenic and acrylic polymers and others that are capable of exchanging cations, with the cross-linked styrenic polymers being preferred.
  • the type of anionic moieties contained by the polymer are those which will exchange metal ions from an aqueous medium.
  • suitable anionic moieties include sulfonic, carboxylic and phosphonic, with sulfonic being preferred.
  • concentration of anionic moieties in the polymer is that concentration which will ensure presence of such moieties in the interior regions of the particles and will enable the polymer to exchange cations from an aqueous medium.
  • concentration of anionic moieties is from about 1 to about 12, and in some cases preferably from about 4.7 to about 5.3, milliequivalents per gram (meq/g) of polymer.
  • cross-linked polymers formed by the addition copolymerization of polymerizable monoethylenically unsaturated monomer or a mixture of such monomer with a cross-linking agent copolymerizable therewith, typically a polyethylenically unsaturated monomer such as divinylbenzene.
  • a cross-linking agent copolymerizable therewith typically a polyethylenically unsaturated monomer such as divinylbenzene.
  • Suitable polymerizable monoethylenically unsaturated monomers, cross-linking agents, catalysts, polymerization media and methods for preparing the cross-linked addition copolymers in suitable particulate form are well-known in the art. Illustrative of such art are U.S.
  • Patents US-A-2,960,480 and US-A-2,788,331 which teach the preparation of gel-type, cross-linked polymers and U.S. Patents US-A-3,637,535 and US-A-3,549,562 which teach the preparation of more porous resins, often called macroporous resins.
  • the mono- vinylidene aromatic such as styrene and monoalkyl-substituted styrenes
  • vinyl toluene, ethylvinyl benzene and vinyl naphthalene are preferred, with styrene being especially preferred.
  • Preferred cross-linking agents include polyvinylidene aromatics such as divinyl benzene, divinyl toluene, divinyl xylene, divinyl naphthalene, trivinyl benzene, divinyl diphenyl ether, divinyl diphenyl sulfone and isopropenyl vinyl benzene; ethylene glycol dimethacrylate and divinyl sulfide, with the polyvinylidene aromatics, especially divinyl benzene, being most preferred.
  • polyvinylidene aromatics such as divinyl benzene, divinyl toluene, divinyl xylene, divinyl naphthalene, trivinyl benzene, divinyl diphenyl ether, divinyl diphenyl sulfone and isopropenyl vinyl benzene
  • ethylene glycol dimethacrylate and divinyl sulfide with the polyvin
  • this matrix polymer contains a plurality of anionic moieties.
  • anionic moieties are sulfonic acid moieties characteristic of any of the conventional sulfonic acid resins that are commercially available for exchanging cations from aqueous solution.
  • this preferred resin is in sodium salt or acid form.
  • exchange resins examples include the resinous condensation products of formaldehyde and phenol sulfonic acid, cationic exchange resins obtained by sulfonating the resinous condensation products of formaldehyde with phenol or with other monohydric or polyhydric phenols, the sulfonated resinous copolymers of monoethylenically unsaturated monomers and polyethylenically unsaturated monomers such as styrene and divinylbenzene.
  • Especially preferred cationic exchange resins are the sulfonated copolymers of styrene cross-linked with from about 1 to about 20, preferably from about 2 to about 4, weight percent of divinylbenzene.
  • Such especially preferred resins have a sufficient concentration of sulfonic acid moieties to have dry weight capacities in the range of from about 4.5 to about 5.2, particularly from about 4.8 to about 5.1 milli-equivalents of hydrogen ion per gram of dry resin (meq H'/g). Such especially preferred resins also have water retention capacities in the range of about 35 to about 90, particularly from about 50 to about 75, weight percent of water in the wet form of the resin. Examples of such especially preferred resins are gel resins in the sodium, hydrogen or lithium form and macroporous and acrylic resins, that are typically in the form of spherical beads.
  • the matrix polymer containing the anionic moieties is in the form of a particulate.
  • such particulate has an average particle diameter in the range from about 10 to about 1200 micrometers, especially from about 500 to about 1200 micrometers.
  • the particles of such particulate are porous so as to permit the transport of metal ions from an aqueous medium into the interior regions of the particles.
  • such resins preferably have micropores having an average pore size in the range from about 10 to about 2000 Angstrom units, especially from about 20 to about 100 Angstrom units, and a surface area from about 0.005 to about 0.15 square meter per gram of wet resin containing approximately 75 weight percent of water, especially from about 0.005 to about 0.1 square meter per gram.
  • Suitable matrix polymers having anionic moieties other than sulfonic acid, such as carboxylic acid and phosphonic acid as well as methods for preparing such materials, are described in Ion-Exchange, Helfferich, McGraw-Hill (1962).
  • the water-soluble compound of the similar metal suitably employed in the practice of this invention is one that (1) is sufficiently soluble such that an aqueous solution of the compound will convert the resin by ion-exchange to the similar metal forms of the resin, (2) reacts with the anionic moieties of the polymer to provide a salt of the metal and a desired portion of the anionic moieties in the interior regions of the particles, and (3) contains a metal similar to the specific metal ion to be removed from the aqueous medium.
  • a metal is similar to the specific metal ion to be removed from the aqueous medium if the metal will form a water-insoluble compound capable of removing the specific metal ion from aqueous solution and retain the specific metal ion during continued contact with the aqueous medium.
  • the similar metal is chemically similar to the specific metal, as predicted by the Periodic Table of elements.
  • the similar metal may be in the same group of the Periodic Table of elements as the specific metal ion, most preferably from a period adjacent to the period of the specific metal ion.
  • the similar metal may be the element adjacent to or nearby the specified metal in the same period of the Periodic Table of elements.
  • the similar metal is preferably barium, with strontium and calcium being less preferred.
  • the similar metal is preferably silver.
  • water-soluble compounds include barium hydroxide and the water-soluble salts of barium such as barium chloride, barium bromide, barium cyanate and barium acetate, with barium hydroxide being especially preferred.
  • Other suitable water-soluble compounds include strontium acetate, strontium chloride, calcium chloride, silver nitrate, calcium acetate and thorium nitrate.
  • the reactant suitably employed in the practice of this invention is a compound that is capable of (1) invading the interior regions of the particles containing salt moieties of the similar metal cation moieties and the anionic moieties and (2) reacting with the similar metal cation moieties to form a water-insoluble compound that is capable of removing the specific metal cation from an aqueous liquid.
  • This compound is sufficiently water-insoluble and has sufficient affinity for the specific metal ion such that it retains the specific metal ion in the particles of the adsorptive resin after repeated contact with the aqueous liquid.
  • this water-insoluble compound is so insoluble in water that less than 2 grams, most preferably less than 0.1 gram, of the compound will dissolve in a liter of water.
  • the reaction of the reactant with the metal form of the wet resin is preferably a strong acid such as sulfuric acid or hydrochloric acid or a moderately strong acid such as phosphoric acid, that will react with the similar metal to form the desired water-insoluble compound.
  • the reactant is sulfuric acid, iodic acid, gaseous sulfur trioxide and similar acids that are known to react with barium to form water-insoluble salts in highly acidic medium, with rather concentrated sulfuric acid, e.g., from 5M to 16M H 2 S0 4 , being more preferred and 6M to 10M H Z S0 4 being most preferred.
  • the - reactant is preferably hydrochloric acid or other acid that reacts with silver to form a water-insoluble compound.
  • the polymer particulate containing the anionic moieties in acid or sodium salt form is immersed or otherwise washed with an aqueous solution of a compound of the similar metal, e.g., barium hydroxide, calcium chloride or silver nitrate.
  • concentration of the aqueous solution of the similar metal compound is not particularly critical as long as a suitable degree of exchange between the similar metal and the anionic moieties of water-insoluble polymer is obtained, particularly in the interior regions of the particles of water-insoluble polymer.
  • the concentration of the water-soluble compound of the similar metal is from about 0.1 to about 20, most preferably from 1 to 10, weight percent in the aqueous solution.
  • the procedures used to carry out the exchange to the similar metal salt form of the resins is in accordance with conventional techniques for cation-exchange involving the exchange of similar metal ions from aqueous solution.
  • the conversion of the similar metal salt form of the resin to the adsorptive resin, which contains the water-insoluble compound of the similar metal that is useful for the removal and retention of the specific metal ions from aqueous solution is preferably accomplished by passing the reactant throughout the interior regions of the particles containing the salt moieties of the similar metal and the anionic moieties.
  • concentration of reactant it is critical that the concentration of reactant be sufficient to overcome the Donnan potential that is characteristic of the particular polymer and anionic moieties involved. If such concentration is not sufficient, it is observed that formation of the water-insoluble compound of the similar metal occurs only on the surfaces of the particle with none being formed within the interior regions of the particle.
  • the concentration of sulfuric acid that is used to treat the barium salt form of most conventional cation-exchange resins derived from copolymers of styrene and divinylbenzene is in the range from about 40 to about 90 weight percent, preferably from about 45 to about 65 weight percent.
  • This adsorptive resin comprises particles of a porous matrix polymer having a plurality of anionic moieties and dispersed within said matrix particles a water-insoluble compound capable of removing and retaining metal ions from an aqueous medium.
  • the water-insoluble compound is present in an amount sufficient to increase the capacity of the resin to remove and retain the desired specific metal ions from an aqueous medium by at least 10 weight percent, preferably by at least 100 weight percent, over the capability of the matrix polymer containing no water-insoluble compound.
  • the adsorptive resin contains from about 1 to about 90, most preferably from about 5 to about 50, weight percent of the water-insoluble compound.
  • a liquid aqueous medium containing specific metal ions such as radium, radioactive strontium, cerium, radioactive cobalt, ruthenium, gold or other precious metals, thorium, arsenic, cadmium, chromium, silver, lead and antimony, are contacted with the particulate of this invention under conditions such that the specific metal ions are transported into the interior regions of the particles whereby such specific metal ions are removed from the aqueous solution and retained in the particles.
  • such contacting is similar to that employed in the exchange of cations from aqueous solution.
  • Concentration of the specific metal ions in the aqueous solution being treated can range from about 0.001 part per trillion to about 10,000 parts per million, preferably from about 0.01 part per trillion to about 1000 parts per million, said parts being based on the weight of the solution.
  • the resin employed was the acid form of a wet 2 percent cross-linked sulfonated styrene/divinylbenzene copolymer cation-exchange resin having particle diameters in the range from 500 to 1200 micrometers, a dry weight capacity of 5.1 milli- equivalents of H' per dry gram, (meq H + /g), a water retention capacity of 75.9 percent and a density of 1.13 g/ml. To 200 g of this resin there is added sufficient 0.3 N Ba(OH) 2 to quantitatively convert the resin to the barium form and provide a small excess of Ba(OH) 2' This barium form of the resin has a water retention capacity of 42 percent and a density of 1.29 g/ml.
  • the resin is contacted with a small amount of acid form of the resin to scavenge excess Ba(OH) 2 .
  • the barium form of the resin is then washed with deionized water and dewatered by filtration.
  • 6M H 2 SO 4 is added to this dewatered barium form of the resin (barium-resin) in an amount sufficient to cover the resin and to maintain the concentration of H z S0 4 at £5M H 2 S0 4 as approximately 80 percent of the water in the barium-resin is released into solution.
  • the barium-resin shrinks initially by 20-40 percent by volume and after 3-5 hours swells to a volume slightly greater than the barium-resin.
  • the resulting adsorptive resin has a density of 1.216 g/ml, dry weight capacity of 2.9 meq of H-/dry gram and a water retention capacity of 65 percent.
  • a 2500-g portion of the resulting adsorptive resin is charged to a column (300 cmx5.08 cm diameter) to a wet settled bed height of 76 cm.
  • An aqueous medium containing 25 picocurie of radium ion per liter is passed up through two of the aforementioned columns connected in series at a rate of 26 liters/minute for a period of 7 months.
  • the eluate from the colum is periodically tested for radioactivity and found to contain less than 2 picocuries of radium per liter during the entire period.
  • the adsorptive resin is then analyzed and found to contain the appropriate quantity of radium ion.
  • an adsorptive resin is prepared according to the procedure of Example 1 except that 8M H 2 SO 4 is substituted for 6M H Z SO 4 .
  • the resulting adsorptive resin has a density of 1.301 g/ml, a water retention capacity of 54.6 percent and a dry weight capacity of 3.1 meq H ⁇ /g.
  • the adsorptive resin is tested for radium removal capability by the procedure described in Example 1 and found to have an effective radium removal capability.
  • Example 2 Following the procedure of Example 1, a 250-g portion of a wet, 2 percent cross-linked, sulfonated styrene/divinylbenzene copolymer cation-exchange resin having particle diameters in the range from 500 to 1200 micrometers, a dry weight capacity (DWC) of 5.18 meq H*/g, a water retention capacity (WRC) of 77.3 percent and a density of 1.09 g/ml is contacted with sufficient 0.5 N Ba(OH) 2 to quantitatively convert the resin to the barium form. This barium-resin is then contacted with 8-10M H 2 S0 4 in an amount sufficient to cover the resin and maintain the concentration of H 2 S0 4 at a5M H 2 SO 4 .
  • DWC dry weight capacity
  • WRC water retention capacity
  • the resulting adsorptive resin is washed with deionized water to remove excess acid and 30 g of the resin is tested for DWC, WRC, percent barium, wet volume capacity in meq H- per ml of actual volume of resin (WVC), and density. The results of the tests are reported in Table I.
  • the adsorptive resin is cycled through the foregoing procedure five additional times and tested for DWC, WRC, percent barium, WVC and density after each cycle.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Treatment Of Water By Ion Exchange (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
EP82106489A 1981-08-03 1982-07-19 Removal of metal ions from aqueous medium using a cation-exchange resin having water-insoluble compound dispersed therein Expired EP0071810B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US28961581A 1981-08-03 1981-08-03
US289615 1981-08-03

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EP0071810A1 EP0071810A1 (en) 1983-02-16
EP0071810B1 true EP0071810B1 (en) 1986-09-17

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EP82106489A Expired EP0071810B1 (en) 1981-08-03 1982-07-19 Removal of metal ions from aqueous medium using a cation-exchange resin having water-insoluble compound dispersed therein

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EP (1) EP0071810B1 (enrdf_load_stackoverflow)
JP (1) JPS5827684A (enrdf_load_stackoverflow)
AU (1) AU551858B2 (enrdf_load_stackoverflow)
CA (1) CA1176799A (enrdf_load_stackoverflow)
DE (1) DE3273343D1 (enrdf_load_stackoverflow)
ZA (1) ZA824916B (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002080192A3 (de) * 2001-03-30 2002-12-12 Wismut Ges Mit Beschraenkter H Verfahren zur abtrennung von radium aus wässern, insbesondere aus durch natururan und seine natürlichen zerfallsprodukte radioaktiv kontaminierten wässern, durch ein aus mehreren komponenten bestehendes reaktives material
WO2002080191A3 (de) * 2001-03-30 2002-12-12 Wismut Ges Mit Beschraenkter H Mittel zur abtrennung von radium aus wässern, insbesondere aus durch natururan und seine natürlichen zerfallsprodukte radioaktiv kontaminierten wässern
US7662292B2 (en) 2007-12-21 2010-02-16 Envirogen Technologies, Inc. Radium selective media and method for manufacturing
WO2017003755A1 (en) 2015-06-30 2017-01-05 Dow Global Technologies Llc Permeable liner

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4515906A (en) * 1983-02-28 1985-05-07 Bend Research, Inc. Anisotropic microporous supports impregnated with polymeric ion-exchange materials
JPS6393355A (ja) * 1986-10-09 1988-04-23 Res Dev Corp Of Japan 金属イオン選択的イオン交換体
FR2798771B1 (fr) * 1999-09-17 2008-03-07 Jean Pronost Dispositif visant a reduire les gaz radioactifs ou nocifs dans l'eau
US20120234765A1 (en) * 2011-03-15 2012-09-20 Lehigh University Method of treatment of produced water and recovery of important divalent cations

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB769121A (en) * 1955-02-14 1957-02-27 Auxiliaire Des Chemins De Fer Improvements in or relating to a process of treating radioactive liquids so as to reduce their radio-activity
GB796441A (en) * 1955-02-28 1958-06-11 Ca Atomic Energy Ltd Decontamination of acidic solutions
GB1064444A (en) * 1963-03-20 1967-04-05 Heinz Riesenhuber Separation of radioactive ions

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002080192A3 (de) * 2001-03-30 2002-12-12 Wismut Ges Mit Beschraenkter H Verfahren zur abtrennung von radium aus wässern, insbesondere aus durch natururan und seine natürlichen zerfallsprodukte radioaktiv kontaminierten wässern, durch ein aus mehreren komponenten bestehendes reaktives material
WO2002080191A3 (de) * 2001-03-30 2002-12-12 Wismut Ges Mit Beschraenkter H Mittel zur abtrennung von radium aus wässern, insbesondere aus durch natururan und seine natürlichen zerfallsprodukte radioaktiv kontaminierten wässern
US7662292B2 (en) 2007-12-21 2010-02-16 Envirogen Technologies, Inc. Radium selective media and method for manufacturing
WO2017003755A1 (en) 2015-06-30 2017-01-05 Dow Global Technologies Llc Permeable liner

Also Published As

Publication number Publication date
JPS5827684A (ja) 1983-02-18
AU551858B2 (en) 1986-05-15
AU8646682A (en) 1983-02-10
DE3273343D1 (en) 1986-10-23
EP0071810A1 (en) 1983-02-16
JPH0140658B2 (enrdf_load_stackoverflow) 1989-08-30
ZA824916B (en) 1984-02-29
CA1176799A (en) 1984-10-23

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