WO2007016222A1 - Method and apparatus for ion sequestration and a nanostructured metal phosphate - Google Patents

Method and apparatus for ion sequestration and a nanostructured metal phosphate Download PDF

Info

Publication number
WO2007016222A1
WO2007016222A1 PCT/US2006/029146 US2006029146W WO2007016222A1 WO 2007016222 A1 WO2007016222 A1 WO 2007016222A1 US 2006029146 W US2006029146 W US 2006029146W WO 2007016222 A1 WO2007016222 A1 WO 2007016222A1
Authority
WO
WIPO (PCT)
Prior art keywords
nanostructured
substance
recited
phosphate
approximately
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/US2006/029146
Other languages
French (fr)
Inventor
Shas V. Mattigod
Glen E. Fryxell
Xiaohong Li
Kent E. Parker
Dawn M. Wellman
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Battelle Memorial Institute Inc
Original Assignee
Battelle Memorial Institute Inc
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 Battelle Memorial Institute Inc filed Critical Battelle Memorial Institute Inc
Publication of WO2007016222A1 publication Critical patent/WO2007016222A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B25/00—Phosphorus; Compounds thereof
    • C01B25/16—Oxyacids of phosphorus; Salts thereof
    • C01B25/26—Phosphates
    • C01B25/37—Phosphates of heavy metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D15/00—Separating processes involving the treatment of liquids with solid sorbents; Apparatus therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
    • B01J20/0207—Compounds of Sc, Y or Lanthanides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
    • B01J20/0214—Compounds of V, Nb, Ta
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
    • B01J20/0248—Compounds of B, Al, Ga, In, Tl
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
    • B01J20/0251—Compounds of Si, Ge, Sn, Pb
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
    • B01J20/0274—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04 characterised by the type of anion
    • B01J20/0292—Phosphates of compounds other than those provided for in B01J20/048
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28002—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their physical properties
    • B01J20/28004—Sorbent size or size distribution, e.g. particle size
    • B01J20/28007—Sorbent size or size distribution, e.g. particle size with size in the range 1-100 nanometers, e.g. nanosized particles, nanofibers, nanotubes, nanowires or the like
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/82—Phosphates
    • B01J29/84—Aluminophosphates containing other elements, e.g. metals, boron
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • 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
    • C02F1/288—Treatment of water, waste water, or sewage by sorption using composite sorbents, e.g. coated, impregnated, multi-layered
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
    • B01J27/14—Phosphorus; Compounds thereof
    • B01J27/16—Phosphorus; Compounds thereof containing oxygen, i.e. acids, anhydrides and their derivates with N, S, B or halogens without carriers or on carriers based on C, Si, Al or Zr; also salts of Si, Al and Zr
    • B01J27/18—Phosphorus; Compounds thereof containing oxygen, i.e. acids, anhydrides and their derivates with N, S, B or halogens without carriers or on carriers based on C, Si, Al or Zr; also salts of Si, Al and Zr with metals other than Al or Zr
    • B01J27/1802—Salts or mixtures of anhydrides with compounds of other metals than V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, e.g. phosphates, thiophosphates
    • B01J27/1813—Salts or mixtures of anhydrides with compounds of other metals than V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, e.g. phosphates, thiophosphates with germanium, tin or lead
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/64—Pore diameter
    • B01J35/647—2-50 nm
    • 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
    • C02F2305/08—Nanoparticles or nanotubes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S977/00—Nanotechnology
    • Y10S977/902—Specified use of nanostructure

Definitions

  • Nanoporous materials can provide an efficient way of selectively concentrating many types of waste materials in a relatively small volume.
  • Silica-based sorbent materials have demonstrated extremely high binding affinities for numerous metals and have precluded subsequent leaching from the laden material.
  • silica-based nanoporous materials can require surface modification and are typically unstable under alkaline conditions (pH > 9).
  • pH > 9 alkaline conditions
  • Nanostructured metal phosphates can be synthesized exhibiting high ion sequestration characteristics and stability at relatively high temperatures and through relatively wide ranges of pH values. Accordingly, one embodiment of the present invention encompasses a nanostructured substance comprising a Lewis acid transition metal bound to a phosphate.
  • the phosphate comprises a primary structural component of the substance and the Lewis acid transition metal is a reducing agent.
  • the nanostructured substance has a Brunner-Emmet-Teller (BET) surface area greater than or equal to approximately 100 m 2 /g, and a distribution coefficient for an analyte, K d , greater than or equal to approximately 5000 ml/g
  • BET Brunner-Emmet-Teller
  • Examples of Lewis acid transition metals can include, but are not limited to, Sn (II), Ti (III), V(III), Sm (II), In (II), In (III), Ce (III), and Eu (II).
  • the nanostructured substance is amorphous. In other embodiments, it can be crystalline. It can have a morphology that is thermally stable and does not collapse after heat treatments. Accordingly, the nanostructured substance can have, for example, a substantially worm-like aggregate morphology and/or a substantially spherical aggregate morphology.
  • the pores can have a diameter greater than or equal to approximately 1.5 nm. Furthermore, the pores can have a diameter less than or equal to approximately 30 nm. In another embodiment, the pores of the nanostructured substance do not form a hexagonal packing structure. In yet another embodiment, the nanostructured substance is not subjected to post-synthesis, surface modification.
  • Another embodiment of the present invention encompasses a process to sequester an analyte from a fluid.
  • the process comprises contacting a nanostructured metal phosphate and a fluid containing an analyte, wherein the nanostructured metal phosphate is a reducing agent for the analyte.
  • the nanostructured metal phosphate comprises a Lewis acid transition metal bound to a phosphate.
  • the phosphate comprises a primary structural component of the substance and the Lewis acid transition metal is a reducing agent.
  • the nanostructured substance has a BET surface area greater than or equal to approximately 100 m 2 /g, and a distribution coefficient for an analyte, Kd, greater than or equal to approximately 5000 ml/g.
  • the process can further comprise physical separation to remove solids from the fluid.
  • Techniques for physical separation can include, but are not limited to, decanting, filtering, centrifuging, and distilling.
  • the solids can comprise at least one analyte sequestered by the nanostructured metal phosphate.
  • Analytes can comprise a material for which the nanostructured metal phosphate is a reducing agent.
  • the analytes comprise an element selected from the group consisting of technetium (VII), neptunium (V), chromium (VI), uranium (VI), arsenic (V), selenium (VI), iodine (VII), thalium (III), and combinations thereof.
  • the fluid can comprise, for example, liquid water, water vapor, organic solvents, supercritical fluids, compressed gases, oils, molten salts, and combinations thereof.
  • Still another embodiment encompasses an ion-sequestration apparatus comprising a vessel and a nanostructured substance.
  • the vessel defines a volume wherein a fluid can contact the nanostructured substance, which fluid contains an analyte to be sequestered.
  • the vessel can comprise an inlet for the fluid and an outlet for the effluent.
  • the vessel can comprise a mesh and/or perforated structure that allows the fluid to pass through and contact the nanostructured substance.
  • the nanostructured substance comprises a Lewis acid transition metal bound to a phosphate, wherein the phosphate comprises a primary structural component of the substance and the Lewis acid transition metal is a reducing agent.
  • the nanostructured substance has a surface area greater than or equal to approximately 100 m 2 /g, and a distribution coefficient for an analyte, IQ, greater than or equal to approximately 5000 ml/g.
  • Fig. 1 is a flow diagram summarizing parameters and starting materials for a surfactant-templating technique that can be used to prepare nanostructured metal phosphates.
  • Fig. 2 is a high-resolution transmission electron microscope (HR-TEM) micrograph of an embodiment of nanostructured tin (II) phosphate.
  • Fig. 3 is a high-resolution transmission electron microscope (HR-TEM) micrograph of an embodiment of nanostructured tin (II) phosphate.
  • Fig. 4 is a high-resolution transmission electron microscope (HR-TEM) micrograph of an embodiment of nanostructured tin (II) phosphate.
  • Fig. 5 is a graph showing low-angle X-ray diffraction (XRD) patterns for surfactant and calcined tin (II) phosphate.
  • Fig. 1 provides an overview of parameters and starting materials for a surfactant-templating technique through which the nanoporous substance can be prepared. Such parameters and starting materials are intended to serve as examples and not as limitations to the scope of the present invention. Thus, alternative synthesis techniques can be utilized to prepare the nanoporous metal phosphate described herein while still falling within the scope of the present invention.
  • the templates 101 can be cationic, anionic, and/or nonionic. More specifically, examples of surfactants include, but are not limited to, cetyltrimethylammonium chloride (CTAC), octadecyltrimethylammonium chloride (ODTMACl), and octadecyltrimethylamnionium bromide (ODTMABr).
  • CTAC cetyltrimethylammonium chloride
  • ODTMACl octadecyltrimethylammonium chloride
  • ODTMABr octadecyltrimethylamnionium bromide
  • Metal reactants 102 of the Lewis acid transition metal can include, but are not limited to, elemental metals, metal salts, organometallics, and combinations thereof. Examples of specific metal salts can include, but are not limited to metal chlorides such as SnCl 2 • 2H 2 O, VCI 3 , and InCl 2 .
  • elemental metal can be used as a metal reactant.
  • a concentrated starting solution for tin can be prepared by dissolving tin metal in concentrated hydrochloric acid.
  • Phosphate reactants 103 can include an acid such as H 3 PO 4 , phosphate esters (e.g. tributyl phosphate), phosphoryl halides (e.g. POCl 3 , PCI5), phosphoric anhydrides (e.g. P 2 Os) 5 and combinations thereof.
  • a mixture comprising the metal reactant, the surfactant, and the phosphate reactant can be subjected to a precipitation period 104.
  • the mixture can be heated to temperatures between approximately 40 0 C and approximately 200 0 C for a duration between approximately 2 minutes and approximately 4 days.
  • the pH of the mixture can range from approximately zero to approximately nine.
  • the surfactant can be removed 105 from the synthetic material by calcining and/or extraction techniques. Vacuum filtration is one technique that can be used to collect the precipitates. Calcination can occur at approximately 150 0 C to 500 0 C.
  • An extraction technique is Soxhlet extraction.
  • the nanostructured substance can have a spherical aggregate morphology.
  • the material can have an irregularly-shaped morphology.
  • the material can have a substantially worm-like aggregate morphology, as shown in Fig. 4.
  • one embodiment of the nanostructured substance does not have pores that are hexagonally packed.
  • the nanostructured substance has a morphology that is stable at temperatures commonly utilized for calcinations.
  • the pore structure resists collapsing upon heating.
  • a common temperature range during calcinations can range from approximately 150 0 C to approximately 500 0 C.
  • Fig. 2 shows a HR-TEM micrograph of nanostructured Sn(II)PO 4 wherein the pore structure is intact after calcination at 500 0 C.
  • Fig. 5 shows low-angle X-ray diffraction (XRD) patterns for a surfactant Sn(II)PO 4 and calcined Sn(II)PO 4 .
  • the d-spacing of the 100 planes in this case were approximately 5.0 run as synthesized, and approximately 4.6 nm after calcination indicating, again, that the pore structure can remain after calcination.
  • Table 1 summarizes examples of some of the conditions and reagents used to synthesize a plurality of embodiments of the present invention as well as the as- synthesized d-spacing. The examples and values shown in Table 1 are not intended to be limitations to the scope of the present invention. Table 1. Exam les of rea ents and conditions for s nthesis of embodiments of the resent invention
  • Additional metals that can be used to synthesize the nanostructured substance include, but are not limited to Ti (III), Sm (II), In (III), Ce (TII), and Eu (II). Sources for these metals can be in the form of elemental metal or metal compounds.
  • the materials summarized in the Table 1 are amorphous and the d-spacing values are a result of the pore structure.
  • Nanostructured tin phosphate was synthesized by preparing 200 mL of 6.87 mmol CTAC, CH 3 (CH 2 ) i 4 N(CH 3 )3Cl, in deionized water. The solution was acidified with 0.626 mL of concentrated phosphoric acid. A concentrated solution of 15.222 g stannic chloride was dissolved in 100 mL hydrochloric acid. 2.5 mL of SnCl 2 /HCl solution was added with stirring at room temperature to the acidified surfactant. The solution stirred for 30 minutes at room temperature and was placed in an oven at 65°C for 48 - 72 hours.
  • the synthetic material was collected via vacuum filtration using a 0.45 ⁇ m filter, washed with deionized water and dried under ambient conditions. Chemical analysis of the synthetic material indicated the structure was composed of Sn, P, and O with a ratio of 1:1:5, respectively. Calcination of the as-synthesized material at 500 0 C produced a material with a surface area of 262 m 2 /g. No structural changes were observed following calcination. Examples of surface areas for a plurality of other tin phosphate samples are summarized in Table 2. Table 2. Surface areas for various nanostructured tin hos hate sam les.
  • Distribution coefficients, K d are defined as a mass-weighted partition coefficient.
  • K values for anal tes is various test matrices.
  • the solid-to-solution ratio is 1:100.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Analytical Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Inorganic Chemistry (AREA)
  • Nanotechnology (AREA)
  • Materials Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Hydrology & Water Resources (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Composite Materials (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)

Abstract

A nanostructured substance, a process for sequestration of ionic waste, and an ion- sequestration apparatus are disclosed in the specification. The nanostructured substance can comprise a Lewis acid transition metal bound to a phosphate, wherein the phosphate comprises a primary structural component of the substance and the Lewis acid transition metal is a reducing agent. The nanostructured substance has a Branner-Emmet-Teller (BET) surface area greater than or equal to approximately 100 m2/g, and a distribution coefficient for an analyte, Kd, greater than or equal to approximately 5000 ml/g. The process can comprise contacting a fluid and a nanostructured metal phosphate. The apparatus can comprise a vessel and a nanostructured metal phosphate. The vessel defines a volume wherein a fluid contacts the nanostructured metal phosphate.

Description

METHODANDAPPARATUS FORIONSEQUESTRATIONANDA NANOSTRUCTUREDMETALPHOSPHATE
Statement Regarding Federally Sponsored Research Or Development [0001] This invention was made with Government support under Contract DE-AC0576RLO1830 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.
Background
[0002] Nanoporous materials can provide an efficient way of selectively concentrating many types of waste materials in a relatively small volume. Silica-based sorbent materials have demonstrated extremely high binding affinities for numerous metals and have precluded subsequent leaching from the laden material. However, silica-based nanoporous materials can require surface modification and are typically unstable under alkaline conditions (pH > 9). Thus, there is a need for an efficient process for ion sequestration and for a robust material having a high surface area and high ion sequestration characteristics.
Summary
[0003] Nanostructured metal phosphates can be synthesized exhibiting high ion sequestration characteristics and stability at relatively high temperatures and through relatively wide ranges of pH values. Accordingly, one embodiment of the present invention encompasses a nanostructured substance comprising a Lewis acid transition metal bound to a phosphate. The phosphate comprises a primary structural component of the substance and the Lewis acid transition metal is a reducing agent. The nanostructured substance has a Brunner-Emmet-Teller (BET) surface area greater than or equal to approximately 100 m2/g, and a distribution coefficient for an analyte, Kd, greater than or equal to approximately 5000 ml/g, Examples of Lewis acid transition metals can include, but are not limited to, Sn (II), Ti (III), V(III), Sm (II), In (II), In (III), Ce (III), and Eu (II).
[0004] In some embodiments, the nanostructured substance is amorphous. In other embodiments, it can be crystalline. It can have a morphology that is thermally stable and does not collapse after heat treatments. Accordingly, the nanostructured substance can have, for example, a substantially worm-like aggregate morphology and/or a substantially spherical aggregate morphology. The pores can have a diameter greater than or equal to approximately 1.5 nm. Furthermore, the pores can have a diameter less than or equal to approximately 30 nm. In another embodiment, the pores of the nanostructured substance do not form a hexagonal packing structure. In yet another embodiment, the nanostructured substance is not subjected to post-synthesis, surface modification.
[0005] Another embodiment of the present invention encompasses a process to sequester an analyte from a fluid. The process comprises contacting a nanostructured metal phosphate and a fluid containing an analyte, wherein the nanostructured metal phosphate is a reducing agent for the analyte. In one embodiment, the nanostructured metal phosphate comprises a Lewis acid transition metal bound to a phosphate. The phosphate comprises a primary structural component of the substance and the Lewis acid transition metal is a reducing agent. The nanostructured substance has a BET surface area greater than or equal to approximately 100 m2/g, and a distribution coefficient for an analyte, Kd, greater than or equal to approximately 5000 ml/g. [0006] The process can further comprise physical separation to remove solids from the fluid. Techniques for physical separation can include, but are not limited to, decanting, filtering, centrifuging, and distilling. The solids can comprise at least one analyte sequestered by the nanostructured metal phosphate. Analytes can comprise a material for which the nanostructured metal phosphate is a reducing agent. In one embodiment, the analytes comprise an element selected from the group consisting of technetium (VII), neptunium (V), chromium (VI), uranium (VI), arsenic (V), selenium (VI), iodine (VII), thalium (III), and combinations thereof. The fluid can comprise, for example, liquid water, water vapor, organic solvents, supercritical fluids, compressed gases, oils, molten salts, and combinations thereof.
[0007] Still another embodiment encompasses an ion-sequestration apparatus comprising a vessel and a nanostructured substance. The vessel defines a volume wherein a fluid can contact the nanostructured substance, which fluid contains an analyte to be sequestered. The vessel can comprise an inlet for the fluid and an outlet for the effluent. Alternatively, the vessel can comprise a mesh and/or perforated structure that allows the fluid to pass through and contact the nanostructured substance. The nanostructured substance comprises a Lewis acid transition metal bound to a phosphate, wherein the phosphate comprises a primary structural component of the substance and the Lewis acid transition metal is a reducing agent. The nanostructured substance has a surface area greater than or equal to approximately 100 m2/g, and a distribution coefficient for an analyte, IQ, greater than or equal to approximately 5000 ml/g.
Description of Drawings [0008] Embodiments of the invention are described below with reference to the following accompanying drawings.
[0009] Fig. 1 is a flow diagram summarizing parameters and starting materials for a surfactant-templating technique that can be used to prepare nanostructured metal phosphates.
[0010] Fig. 2 is a high-resolution transmission electron microscope (HR-TEM) micrograph of an embodiment of nanostructured tin (II) phosphate.
[0011] Fig. 3 is a high-resolution transmission electron microscope (HR-TEM) micrograph of an embodiment of nanostructured tin (II) phosphate.
[0012] Fig. 4 is a high-resolution transmission electron microscope (HR-TEM) micrograph of an embodiment of nanostructured tin (II) phosphate.
[0013] Fig. 5 is a graph showing low-angle X-ray diffraction (XRD) patterns for surfactant and calcined tin (II) phosphate.
Detailed Description
[0014] Fig. 1 provides an overview of parameters and starting materials for a surfactant-templating technique through which the nanoporous substance can be prepared. Such parameters and starting materials are intended to serve as examples and not as limitations to the scope of the present invention. Thus, alternative synthesis techniques can be utilized to prepare the nanoporous metal phosphate described herein while still falling within the scope of the present invention.
[0015] Referring to Fig. 1, the templates 101 can be cationic, anionic, and/or nonionic. More specifically, examples of surfactants include, but are not limited to, cetyltrimethylammonium chloride (CTAC), octadecyltrimethylammonium chloride (ODTMACl), and octadecyltrimethylamnionium bromide (ODTMABr). Metal reactants 102 of the Lewis acid transition metal can include, but are not limited to, elemental metals, metal salts, organometallics, and combinations thereof. Examples of specific metal salts can include, but are not limited to metal chlorides such as SnCl2 • 2H2O, VCI3, and InCl2. Alternatively, elemental metal can be used as a metal reactant. For example, a concentrated starting solution for tin can be prepared by dissolving tin metal in concentrated hydrochloric acid. Phosphate reactants 103 can include an acid such as H3PO4, phosphate esters (e.g. tributyl phosphate), phosphoryl halides (e.g. POCl3, PCI5), phosphoric anhydrides (e.g. P2Os)5 and combinations thereof.
[0016] According to the present example, a mixture comprising the metal reactant, the surfactant, and the phosphate reactant can be subjected to a precipitation period 104. During precipitation, the mixture can be heated to temperatures between approximately 40 0C and approximately 200 0C for a duration between approximately 2 minutes and approximately 4 days. The pH of the mixture can range from approximately zero to approximately nine. After collecting the precipitates, the surfactant can be removed 105 from the synthetic material by calcining and/or extraction techniques. Vacuum filtration is one technique that can be used to collect the precipitates. Calcination can occur at approximately 150 0C to 500 0C. One example of an extraction technique is Soxhlet extraction.
[0017] Samples of the nanostructured substance prepared using conditions similar to those described above exhibited a variety of properties. For example, referring to the embodiment shown in Fig. 2, the nanostructured substance can have a spherical aggregate morphology. On a slightly larger scale, as shown in Fig. 3, the material can have an irregularly-shaped morphology. Furthermore, the material can have a substantially worm-like aggregate morphology, as shown in Fig. 4. Referring to Fig. 2, one embodiment of the nanostructured substance does not have pores that are hexagonally packed.
[0018] In general, the nanostructured substance has a morphology that is stable at temperatures commonly utilized for calcinations. In other words, the pore structure resists collapsing upon heating. A common temperature range during calcinations can range from approximately 150 0C to approximately 500 0C. Fig. 2 shows a HR-TEM micrograph of nanostructured Sn(II)PO4 wherein the pore structure is intact after calcination at 500 0C. Fig. 5 shows low-angle X-ray diffraction (XRD) patterns for a surfactant Sn(II)PO4 and calcined Sn(II)PO4. The d-spacing of the 100 planes in this case were approximately 5.0 run as synthesized, and approximately 4.6 nm after calcination indicating, again, that the pore structure can remain after calcination.
[0019] Table 1 summarizes examples of some of the conditions and reagents used to synthesize a plurality of embodiments of the present invention as well as the as- synthesized d-spacing. The examples and values shown in Table 1 are not intended to be limitations to the scope of the present invention. Table 1. Exam les of rea ents and conditions for s nthesis of embodiments of the resent invention
Figure imgf000008_0001
Additional metals that can be used to synthesize the nanostructured substance include, but are not limited to Ti (III), Sm (II), In (III), Ce (TII), and Eu (II). Sources for these metals can be in the form of elemental metal or metal compounds. The materials summarized in the Table 1 are amorphous and the d-spacing values are a result of the pore structure.
Example: Preparation of nanostructured tin phosphate and sequestration of 99Tc [0020] Nanostructured tin phosphate was synthesized by preparing 200 mL of 6.87 mmol CTAC, CH3(CH2) i4N(CH3)3Cl, in deionized water. The solution was acidified with 0.626 mL of concentrated phosphoric acid. A concentrated solution of 15.222 g stannic chloride was dissolved in 100 mL hydrochloric acid. 2.5 mL of SnCl2/HCl solution was added with stirring at room temperature to the acidified surfactant. The solution stirred for 30 minutes at room temperature and was placed in an oven at 65°C for 48 - 72 hours. The synthetic material was collected via vacuum filtration using a 0.45μm filter, washed with deionized water and dried under ambient conditions. Chemical analysis of the synthetic material indicated the structure was composed of Sn, P, and O with a ratio of 1:1:5, respectively. Calcination of the as-synthesized material at 5000C produced a material with a surface area of 262 m2/g. No structural changes were observed following calcination. Examples of surface areas for a plurality of other tin phosphate samples are summarized in Table 2. Table 2. Surface areas for various nanostructured tin hos hate sam les.
Figure imgf000009_0001
[0021] Batch contact experiments were performed with the nanostructured Sn(II)PO4
99 using 2000 dpm/mL spiked solutions of Tc in 0.002 M NaHCO3 and in groundwater. The groundwater had a competing sulfate concentration of 0.02 M. Equilibrium was achieved in less than an hour at a solution-to-solids ratio of 100. Therefore a batch contact time of 2 hours was used to ensure that these values reasonably represented true equilibrium conditions. Under these conditions the nanoporous, calcined tin (II)
99 phosphate removed more than approximately 95% of the Tc from solution. Distribution coefficients, Kd, are defined as a mass-weighted partition coefficient. Kd
values were typically greater than approximately 5,000 ml/g in groundwater, with
99 individual measurements as high as 1,800,000 ml/g being observed for removal of Tc from the 0.002 M NaHCO3 solution. At a solution to solids ratio of 100, a Kd value of
99
100,000 indicates that at equilibrium there was 1000 times as much Tc in the nanoporous metal phosphate phase as there was remaining in the supernantant solution. [0022] The affinity of tin (II) phosphate for additional anionic species was also evaluated for Np(V). Batch studies were conducted with a 2000 dpm/mL solution of Np(V) in 0.002 M NaHCO3. Equilibrium was again achieved in less than an hour at a
solution to solids ratio of 100. Therefore a batch contact time of 2 hours was used to insure these values represent true equilibrium conditions. Under these conditions the nanoporous, calcined tin (II) phosphate removed more than approximately 95% of the Np(V) from solution. Kd values were typically greater than 100, 000 for Np(V) in 0.002
M NaHCO3 solution. Table 3 summarizes the K^ values for analytes in various test
matrices.
Table 3. K values for anal tes is various test matrices. The solid-to-solution ratio is 1:100.
Figure imgf000010_0001
Figure imgf000011_0001
While batch contact experiments have been described in the proof-of-principle tests above, the scope of the present invention is not limited to batch processes for ion sequestration.
[0023] While a number of embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the invention in its broader aspects. The appended claims, therefore, are intended to cover all such changes and modifications as they fall within the true spirit and scope of the invention.

Claims

ClaimsWe claim:
1. A nanostructured substance comprising a Lewis acid transition metal bound to a phosphate, wherein the phosphate comprises a primary structural component of the substance and the Lewis acid transition metal is a reducing agent, the nanostructured substance having a surface area greater than or equal to approximately 100 m2/g, and a distribution coefficient for an analyte, ka, greater than or equal to approximately 5000 ml/g.
2. The nanostructured substance as recited in Claim 1 , wherein the analyte comprises an element selected from the group consisting of technetium (VII), neptunium (V), chromium (VI), uranium (VI), arsenic (V), selenium (VI), iodine (VII), thalium (III), and combinations thereof.
3. The nanostructured substance as recited in Claim 1, having a substantially worm- like aggregate morphology.
4. The nanostructured substance as recited in Claim 1 , having a substantially spherical aggregate morphology.
5. The nanostructured substance as recited in Claim 1, wherein said Lewis acid transition metal is selected from the group consisting of Sn (II), Ti (III), V(III), Sm (II), In (II), In (III), Ce (III), Eu (II), and combinations thereof.
6. The nanostructured substance as recited in Claim 1, wherein the nanostructured substance is amorphous.
7. The nanostructured substance as recited in Claim 1, comprising pores having a diameter greater than or equal to approximately 1.5 nm.
8. The nanostructured substance as recited in Claim 1, comprising pores having a diameter less than or equal to approximately 30 nm.
9. The nanostructured substance as recited in Claim 1, wherein the surface of the nanostructured substance is not post-synthesis modified.
10. The nanostructured substance as recited in Claim 1, wherein pores of the nanostructured substance do not form a hexagonal packing structure.
11. A process comprising the step of contacting a nanostructured metal phosphate and a fluid comprising an analyte, wherein the nanostructured metal phosphate is a reducing agent for the analyte, thereby sequestering the analyte from the fluid mixture.
12. The process as recited in Claim 11, further comprising the step of physically separating to remove solids from the fluid.
13. The process as recited in Claim 12, wherein the step of physically separating is decanting, filtering, centrifuging, distilling, or combinations thereof.
14. The process as recited in Claim 11, wherein the fluid is selected from the group consisting of liquid water, water vapor, organic solvents, supercritical fluids, compressed gases, oils, molten salts, and combinations thereof.
15. The process as recited in Claim 11, the nanostructured metal phosphate comprising a Lewis acid transition metal bound to a phosphate, wherein the phosphate comprises a primary structural component of the substance and the Lewis acid transition metal is a reducing agent, the nanostructured substance having a surface area greater than or equal to approximately 100 m2/g, and a distribution coefficient for the analyte, Kj, greater than or equal to approximately 5000 ml/g.
16. The process as recited in Claim 11, wherein said Lewis acid transition metal is selected from the group consisting of Sn (II), Ti (III), V(III), Sm (II), In (II), In (III), Ce (III), Eu (II), and combinations thereof.
17. The process as recited in Claim 11, wherein the analyte comprises an element selected from the group consisting of technetium (VII), neptunium (V), chromium (VI), uranium (VI), arsenic (V), selenium (VI), iodine (VII), Thalium (III), and combinations thereof.
18. The process as recited in Claim 11, wherein the surface of the nanostructured substance is not post-synthesis modified.
19. The process as recited in Claim 11, wherein pores of the nanostructured substance do not form a hexagonal packing structure.
20. An ion-sequestration apparatus comprising: a. a vessel; and b. a nanostructured substance comprising a Lewis acid transition metal bound to a phosphate, wherein the phosphate comprises a primary structural component of the substance and the Lewis acid transition metal is a reducing agent, the nanostructured substance having a surface area greater than or equal to approximately 100 m2/g, and a distribution coefficient for an analyte, K<j, greater than or equal to approximately 5000 ml/g; said vessel defining a volume wherein a fluid contacts the nanostructured substance, said fluid comprising an analyte.
PCT/US2006/029146 2005-08-01 2006-07-28 Method and apparatus for ion sequestration and a nanostructured metal phosphate Ceased WO2007016222A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11/195,394 2005-08-01
US11/195,394 US7691637B2 (en) 2005-08-01 2005-08-01 Method and apparatus for ion sequestration and a nanostructured metal phosphate

Publications (1)

Publication Number Publication Date
WO2007016222A1 true WO2007016222A1 (en) 2007-02-08

Family

ID=37398733

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2006/029146 Ceased WO2007016222A1 (en) 2005-08-01 2006-07-28 Method and apparatus for ion sequestration and a nanostructured metal phosphate

Country Status (2)

Country Link
US (1) US7691637B2 (en)
WO (1) WO2007016222A1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010115147A2 (en) * 2009-04-02 2010-10-07 Life Technologies Corporation Biomolecular sensing with metal-nanostructures
US8025726B1 (en) 2010-04-08 2011-09-27 Nalco Company Sulfur containing silica particle
US8377194B2 (en) 2010-04-08 2013-02-19 Nalco Company Sulfur containing silica particle
US8333835B2 (en) 2010-04-08 2012-12-18 Nalco Company Sulfur containing silica particle
US8936772B2 (en) 2010-04-08 2015-01-20 Ecolab Usa Inc. Silica containing particle
US8609046B2 (en) 2011-10-07 2013-12-17 Nalco Company Gas stream treatment process

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003176112A (en) * 2001-12-11 2003-06-24 National Institute Of Advanced Industrial & Technology Porous tin phosphate and method for producing the same
US20030196966A1 (en) * 2002-04-17 2003-10-23 Hughes Kenneth D. Reactive compositions for fluid treatment

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4800024A (en) * 1986-04-07 1989-01-24 Iso-Clear Systems Corporation Removal of heavy metals and heavy metal radioactive isotopes from liquids
US4902665A (en) * 1986-04-07 1990-02-20 Iso-Clear Systems Corporation Removal of heavy metals and heavy metal radioactive isotopes from liquids

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003176112A (en) * 2001-12-11 2003-06-24 National Institute Of Advanced Industrial & Technology Porous tin phosphate and method for producing the same
US20030196966A1 (en) * 2002-04-17 2003-10-23 Hughes Kenneth D. Reactive compositions for fluid treatment

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
FRYXELL G ET AL.: "Nanoporous Ti & Zr Phosphate Getter Materials", WORKSHOP ON DEVELOPMENT OF RADIONUCLIDE GETTERS FOR THE YUCCA MOUNTAIN WASTE REPOSITORY: PROCEEDINGS. SANDIA REPORT SAND2006-0947, 1 March 2006 (2006-03-01), pages 40 - 41, XP002409492, Retrieved from the Internet <URL:http://www.osti.gov/energycitations/servlets/purl/878572-l5FTWN/> [retrieved on 20061128] *
JOW H N ET AL.: "RADIONUCLIDE ABSORBERS DEVELLOPMENT PROGRAM OVERVIEW OFFICE OF CIVILIAN RADIOACTIVE WASTE MANAGEMENT (OCRWM), SCIENCE AND TECHNOLOGY PROGRAM", PROCEEDINGS OF THE WM05 CONFERENCE, FEBRUARY 27- MARCH 3, 2005, 27 February 2005 (2005-02-27), Tucson, AZ, pages 1 - 15, XP002409617, Retrieved from the Internet <URL:http://www.wmsym.org/abstracts/pdfs/5133.pdf> [retrieved on 20061128] *
MA Y ET AL: "A review of zeolite-like porous materials", MICROPOROUS AND MESOPOROUS MATERIALS, ELSEVIER SCIENCE PUBLISHING, NEW YORK, US, vol. 37, no. 1-2, May 2000 (2000-05-01), pages 243 - 252, XP004196676, ISSN: 1387-1811 *
MAL N K ET AL: "Synthesis of a novel mesoporous tin phosphate, SnPO4", CHEM. COMMUN., no. 2, 7 February 2002 (2002-02-07), pages 112 - 113, XP002409570 *

Also Published As

Publication number Publication date
US20070026531A1 (en) 2007-02-01
US7691637B2 (en) 2010-04-06

Similar Documents

Publication Publication Date Title
Hamdi et al. Removal of phosphate ions from aqueous solution using Tunisian clays minerals and synthetic zeolite
Thakkar et al. Synthesis and characterization of zirconium titanium phosphate and its application in separation of metal ions
Harja et al. Removal of heavy metal ions from aqueous solutions using low-cost sorbents obtained from ash
JP5928960B2 (en) Manufacturing method of ion adsorbent
Ghosh et al. Optimization study of adsorption parameters for removal of fluoride using aluminium-impregnated potato plant ash by response surface methodology
CN101952204A (en) Ferric arsenate powder
Dhongde et al. Development of nanohybrid adsorbent for defluoridation from aqueous systems
Islam et al. Polyacrylamide thorium (IV) phosphate as an important lead selective fibrous ion exchanger: synthesis, characterization and removal study
Ali et al. Vanadium (V) removal and recovery by adsorption onto modified activated carbon derived from natural hydroxyapatite
US7691637B2 (en) Method and apparatus for ion sequestration and a nanostructured metal phosphate
El-kordy et al. Synthesis of clay/Fe/ZSM-5 composite membrane for chromium (vi) removal from aqueous media and its electrochemical performance
Nabi et al. A new electron exchange material Ti (IV) iodovanadate: Synthesis, characterization and analytical applications
CN101663241B (en) Porous iron oxide, process for producing the same, and method of treating water
Jignasa et al. A study on equilibrium and kinetics of ion exchange of alkaline earth metals using an inorganic cation exchanger–zirconium titanium phosphate
Maheria et al. Studies on kinetics, thermodynamics and sorption characteristics of an inorganic ion exchanger-Titanium phosphate towards Pb (II), Bi (III) and Th (IV)
CN102239119B (en) Method for treating nitrogenous wastewater
JP3859001B2 (en) Arsenic sorption material with excellent stability and purification method for contaminated water using the same
JP3577515B2 (en) Highly selective barium adsorbent and method for producing the same
Iqbal et al. Synthesis and characterization of sodium bis (2-ethylhexyl) sulfosuccinate based tin (IV) phosphate cation exchanger: Selective for Cd2+, Zn2+ and Hg2+ ions
Abu-Hawwas et al. Characterization of Jordanian Porcelanite rock with reference to the adsorption behavior of lead ions from aqueous solution
JP2005162513A (en) Method for producing zeolitic soil from water purification plant generated soil, wastewater treatment method and used zeolitic soil treatment method
Maheria et al. Studies on sorption and elution behaviour of dyes using titanium phosphonate
Carter et al. CCXLVIII.—The system ferric oxide–phosphoric acid–water. A new phosphate
RU2831541C1 (en) Method of producing nanostructured x-ray amorphous cesium sorbent
JPH105585A (en) Lithium ion adsorbing agent

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 06800376

Country of ref document: EP

Kind code of ref document: A1