WO2019060358A1 - Adsorbent granules for removal of heavy metals and method of making - Google Patents

Adsorbent granules for removal of heavy metals and method of making Download PDF

Info

Publication number
WO2019060358A1
WO2019060358A1 PCT/US2018/051654 US2018051654W WO2019060358A1 WO 2019060358 A1 WO2019060358 A1 WO 2019060358A1 US 2018051654 W US2018051654 W US 2018051654W WO 2019060358 A1 WO2019060358 A1 WO 2019060358A1
Authority
WO
WIPO (PCT)
Prior art keywords
adsorbent granules
water
hydraulic binder
oxide material
composition
Prior art date
Application number
PCT/US2018/051654
Other languages
French (fr)
Inventor
Qian Yang
Minling Liu
Shuwen Peng
Hui Zhong WANG
Rajiv Banavali
Original Assignee
Honeywell International 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 Honeywell International Inc. filed Critical Honeywell International Inc.
Publication of WO2019060358A1 publication Critical patent/WO2019060358A1/en

Links

Classifications

    • 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
    • B01J20/06—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising oxides or hydroxides of metals not provided for in group B01J20/04
    • 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
    • B01J20/10—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate
    • B01J20/16—Alumino-silicates
    • B01J20/165—Natural alumino-silicates, e.g. zeolites
    • 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
    • B01J20/10—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate
    • B01J20/16—Alumino-silicates
    • B01J20/18—Synthetic zeolitic molecular sieves
    • 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
    • B01J20/22—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising organic material
    • B01J20/26—Synthetic macromolecular compounds
    • 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
    • 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
    • B01J20/28011—Other properties, e.g. density, crush strength
    • 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
    • B01J20/28014—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 form
    • B01J20/28016—Particle form
    • B01J20/28019—Spherical, ellipsoidal or cylindrical
    • 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
    • B01J20/28014—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 form
    • B01J20/2803—Sorbents comprising a binder, e.g. for forming aggregated, agglomerated or granulated products
    • 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
    • B01J20/28054—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 surface properties or porosity
    • B01J20/28057—Surface area, e.g. B.E.T specific surface area
    • 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
    • B01J20/28054—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 surface properties or porosity
    • B01J20/28057—Surface area, e.g. B.E.T specific surface area
    • B01J20/28061—Surface area, e.g. B.E.T specific surface area being in the range 100-500 m2/g
    • 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
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/3028—Granulating, agglomerating or aggregating
    • 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
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/305—Addition of material, later completely removed, e.g. as result of heat treatment, leaching or washing, e.g. for forming pores
    • B01J20/3064—Addition of pore forming agents, e.g. pore inducing or porogenic agents
    • 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
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/3071—Washing or leaching
    • 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
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/3078—Thermal treatment, e.g. calcining or pyrolizing
    • 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
    • C02F1/281—Treatment of water, waste water, or sewage by sorption using inorganic sorbents
    • 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
    • C02F1/285—Treatment of water, waste water, or sewage by sorption using synthetic organic sorbents
    • 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
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B18/00—Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone
    • C04B18/02—Agglomerated materials, e.g. artificial aggregates
    • C04B18/021—Agglomerated materials, e.g. artificial aggregates agglomerated by a mineral binder, e.g. cement
    • 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
    • B01J2220/00—Aspects relating to sorbent materials
    • B01J2220/40—Aspects relating to the composition of sorbent or filter aid materials
    • B01J2220/42—Materials comprising a mixture of inorganic materials
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C02F2101/103—Arsenic compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C02F2101/20—Heavy metals or heavy metal compounds
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
    • C04B2111/00793—Uses not provided for elsewhere in C04B2111/00 as filters or diaphragms

Definitions

  • the present invention relates to adsorbents for water purification. More specifically, the present invention relates to adsorbents for removal of heavy metals from water and methods for making adsorbents for removal of heavy metals from water.
  • Heavy metals for example, arsenic (As), lead (Pb), cadmium (Cd) and mercury (Hg), may be found in harmful concentrations in some drinking water.
  • the sources of the heavy metals may be naturally occurring or result from industrial pollution.
  • the heavy metals can be removed by a number of techniques including reverse osmosis or distillation. However, these techniques can be costly because they can be energy and resource intensive.
  • a less costly method of heavy metal removal can be the filtration of water through a cartridge containing a granular adsorbent that is designed to remove heavy metals.
  • granular adsorbents may not be able to remove heavy metals with great efficiency, resulting in larger and more costly filter cartridges.
  • a composition of adsorbent granules for the removal of heavy metals from water includes a metal oxyhydroxide material, a metal oxide material, a
  • a method of making a plurality of adsorbent granules includes mixing together a filter material and a hydraulic binder, combining the mixture of the filter material and the hydraulic binder with water to form a paste, granulating the paste to form the plurality of adsorbent granules, applying additional water to the surface of each of the plurality of adsorbent granules, holding the plurality of adsorbent granules in a sealed container at a temperature between 18°C and 30°C for a cementation period, and washing the plurality of adsorbent granules in additional water.
  • the filter material includes a metal oxyhydroxide material, a metal oxide material, and a manganese oxide material.
  • the method can include dissolving a pore-forming agent in the water before combining the mixture of the filter material and the hydraulic binder with the water to form the paste.
  • the pore-forming agent includes an organic compound that is water soluble or water miscible.
  • Various embodiments concern a composition of adsorbent granules for the removal of heavy metals from water.
  • Each of the plurality of adsorbent granules includes a metal oxyhydroxide material, a metal oxide material, a manganese oxide material, and a hydraulic binder.
  • the hydraulic binder includes at least one of: Portland cement, calcium aluminate cement, sulphoaluminate cement, hydroxylapatite, tricalcium phosphate, and fluoaluminate cement.
  • the hydraulic binder is from 5 wt. % to 20 wt. % of the composition. In some embodiments, the hydraulic binder is from 10 wt. % to 12 wt. % of the
  • each of the plurality of adsorbent granules further includes a molecular sieve material. In some embodiments, a ratio of the metal oxyhydroxide material to the metal oxide material to the manganese oxide material to the molecular sieve material is 0.5-2 to 0.5-2 to 0.5-2 to 0.01 -1. In some embodiments, each of the plurality of adsorbent granules further includes a residue of a pore-forming agent, the pore-forming agent including an organic compound that is water soluble or water miscible. In some particular embodiments, the pore-forming agent includes at least one of: poly(ethylene glycol), glycerol, glycol, dimethylformamide, and dimethyl sulfoxide. In some particular embodiments, the pore-forming agent includes
  • the metal oxyhydroxide material includes iron oxyhydroxide
  • the metal oxide material includes titanium dioxide
  • manganese oxide material includes manganese sand.
  • Various embodiments concern a method of making a plurality of adsorbent granules.
  • the method includes mixing together a filter material and a hydraulic binder, combining the mixture of the filter material and the hydraulic binder with water to form a paste, granulating the paste to form the plurality of adsorbent granules, applying additional water to a surface of each of the plurality of adsorbent granules, holding the plurality of adsorbent granules in a sealed container at a temperature between 18°C and 30°C for a cementation period, and washing the plurality of adsorbent granules in additional water.
  • the filter material includes a metal oxyhydroxide material, a metal oxide material, and a manganese oxide material.
  • the hydraulic binder includes at least one of: Portland cement, calcium aluminate cement,
  • the hydraulic binder is from 5 wt. % to 20 wt. % of a total weight of the filter material and the hydraulic binder. In some particular
  • the hydraulic binder is from 10 wt. % to 12 wt. % of a total weight of the filter material and the hydraulic binder.
  • the metal oxyhydroxide material includes iron oxyhydroxide
  • the metal oxide material includes titanium dioxide
  • the manganese oxide material includes manganese sand.
  • the filter material further includes a molecular sieve material. In some particular embodiments, a ratio of the metal oxyhydroxide material to the metal oxide material to the manganese oxide material to the molecular sieve material is 0.5-2 to 0.5-2 to 0.5-2 to 0.01 -1.
  • the method further includes dissolving a pore-forming agent in the water before combining the mixture of the filter material and the hydraulic binder with the water to form the paste, the pore-forming agent including an organic compound that is water soluble or water miscible.
  • the pore-forming agent includes at least one of: poly(ethylene glycol), glycerol, glycol, dimethylformamide, and dimethyl sulfoxide.
  • the pore- forming agent includes poly(ethylene glycol) with a weight average molecular weight from 100 grams/mole to 4,000 grams/mole.
  • FIG. 1 is a graph illustrating a crush strength of samples from each of three groups of adsorbent granules according to embodiments of the disclosure compared to a crush strength of a samples of a fourth group of adsorbent granules including a clay binder that required high temperature sintering.
  • FIG. 2 is a graph illustrating a specific surface area (Brunauer-Emmett- Teller surface area) of samples from each of two groups of adsorbent granules according to embodiments of this disclosure compared to the specific surface area of samples from each of two other groups of adsorbent granules including a clay binder that required high temperature sintering.
  • a specific surface area Brunauer-Emmett- Teller surface area
  • FIG. 3 is a graph illustrating arsenic removal efficiency of adsorbent granules, according to embodiments of this disclosure.
  • Adsorbent granules for use in adsorbing heavy metals from water are often made of a combination of filter materials held together with clay binders.
  • the filter materials can be pulverized into a fine powder, mixed together with the binder, and then formed into adsorbent granules sized for use in, for example, a filter cartridge for household applications.
  • the synergistic combination of the filter materials in close proximity can result in greater than 90% efficiency in removal of at least some heavy metals.
  • the filter materials can include a metal oxyhydroxide material, such as iron oxyhydroxide (FeOOH), which is a highly effective in adsorbing heavy metals, such as arsenic.
  • FeOOH iron oxyhydroxide
  • the binder holds the filter materials together to provide an adsorbent granule with a crush strength of at least 7 Newtons (N) to be able to withstand the rigors of manufacturing and handling associated with the fabrication and use of filter cartridges.
  • N Newtons
  • adsorbent granules using clay binders must be sintered, or calcined, at temperatures as high as 400°C to 800°C
  • FeOOH is thermally unstable and will tend to convert to ferric oxide (Fe2O3) at temperatures above 150°C, according to its thermogravimetric analysis (TGA) curve. This conversion can reduce the removal efficiency of the filter material to as low as 60% because Fe203 is not as effective in adsorbing heavy metals as FeOOH.
  • Adsorbent granules employ hydraulic binders.
  • Hydraulic binders are materials that chemically react with water to set and harden. Hydraulic binders can cement or bind together the filter materials at or near room temperature. Hydraulic binders do not require high temperatures to impart the desired strength to the adsorbent granules.
  • Adsorbent granules including a hydraulic binder can exhibit a higher removal efficiency compared to adsorbent granules including a clay binder which much be exposed to high temperatures.
  • adsorbent granules including the hydraulic binder are not exposed to high temperatures, more of the metal oxyhydroxide is preserved for used in filtering heavy metals from water.
  • heavy metal removal efficiency is further enhanced by the use of a water soluble or water miscible organic pore-forming agent to increase the specific surface area of the adsorbent granules.
  • Such adsorbent granules can further include a residue of the organic pore-forming agent.
  • Embodiments of the disclosure include a method for making the adsorbent granules that includes applying water to the adsorbent granules including the hydraulic binder and holding them in a sealed container at or near room temperature for a period of time to permit the binder to cement the filter materials together.
  • the method provides for the formation of adsorbent granules of sufficient crush strength without the use of high temperature sintering.
  • heavy metal removal efficiency is further enhanced by adding a water soluble or water miscible organic pore- forming agent to the adsorbent granules.
  • the pore-forming agent is present during the granulation and cementing of the adsorbent granules, and then much of it is rinsed away after the cementing, leaving an open pore structure through much of each of the adsorbent granules, increasing the specific surface area of the adsorbent granules.
  • the adsorbent granules can be formed by mixing together a filter material and a hydraulic binder, and then combining the mixture with water to form a paste.
  • the paste can be granulated to form the adsorbent granules.
  • Some techniques used for granulating include compaction granulation, centrifugal granulation, melting granulation, spraying granulation, and extrusion pelletizing, as are known in the art.
  • the filter material can include a metal oxyhydroxide material, a metal oxide material, and a manganese oxide material.
  • the metal oxyhydroxide material can include, for example, an iron oxyhydroxide (FeO(OH)) or a titanium oxyhydroxide (TiO(OH)).
  • the metal oxide material can include, for example, titanium dioxide (T1O2), ferrous oxide (FeO), or ferric oxide (Fe2O3).
  • the manganese oxide (MnO) material can be in the form of, for example, a manganese sand material.
  • the filter material powder can further include a molecular sieve material, such as, for example, activated alumina, or a zeolite, such as zeolite 13X.
  • the weight ratios of the metal oxyhydroxide material to the metal oxide material to the manganese oxide material to the molecular sieve material can range from 0.5-2 to 0.5-2 to 0.5-2 to 0.01 -1 . In some embodiments, the weight ratios of the metal oxyhydroxide material to the metal oxide material to the manganese oxide material to the molecular sieve material can be 1 to 1 to 1 to 0.6, otherwise expressed as: 1 : 1 : 1 :0.6.
  • the weight of the metal oxyhydroxide material as a percentage of the total weight of the filter material powder can be as low as 2 wt. %, 5 wt. %, or 10 wt. %, or as high as 30 wt. %, 60 wt. %, or 90 wt. %, or be any weight percentage between any two of the preceding weight percentages.
  • the weight of the metal oxyhydroxide material as a percentage of the total weight of the filter material powder can range from 2 wt. % to 90 wt.%, 5 wt. % to 60 wt.%, or 10 wt. % to 30 wt.%.
  • the weight of the metal oxide material as a percentage of the total weight of the filter material powder can be as low as 2 wt. %, 5 wt. %, or 10 wt. %, or as high as 30 wt. %, 60 wt. %, or 90 wt. %, or be any weight percentage between any two of the preceding weight percentages.
  • the weight of the metal oxide material as a percentage of the total weight of the filter material powder can range from 2 wt. % to 90 wt.%, 5 wt. % to 60 wt.%, or 10 wt. % to 30 wt.%.
  • the weight of the manganese oxide material as a percentage of the total weight of the filter material powder can be as 2 wt. %, 5 wt. %, or 10 wt. %, or as high as 30 wt. %, 60 wt. %, or 90 wt. %, or be any weight percentage between any two of the preceding weight percentages.
  • the weight of the manganese oxide material as a percentage of the total weight of the filter material powder can be as 2 wt. %, 5 wt. %, or 10 wt. %, or as high as 30 wt. %, 60 wt. %, or 90 wt. %, or be any weight percentage between any two of the preceding weight percentages.
  • the weight of the manganese oxide material as a percentage of the total weight of the filter material powder can be as 2 wt. %, 5 wt. %, or 10 wt. %, or as high as 30 wt.
  • the weight of the manganese oxide material as a percentage of the total weight of the filter material powder can range from 2 wt. % to 90 wt.%, 5 wt. % to 60 wt.%, or 10 wt. % to 30 wt.%.
  • the weight of the molecular sieve material as a percentage of the total weight of the filter material powder can be as low as 0.5 wt. %, 2 wt. %, or 5 wt. %, or as high as 10 wt. %, 20 wt. %, or 30 wt. %, or be any weight percentage between any two of the preceding weight percentages.
  • the weight of the molecular sieve material as a percentage of the total weight of the filter material powder can range from 0.5 wt. % to 30 wt.%, 2 wt. % to 20 wt.%, or 5 wt. % to 10 wt.%.
  • the filter material can be in the form of a fine powder having a median powder particle size as small as 0.05 microns (pm), 0.1 pm, 0.2 pm, 0.3 pm, 0.5 pm, 1 pm, or 2 pm, or as large as 3 pm, 5 pm, 10 pm, 20 pm, 30 pm, 50 pm, or 100 pm, or between any two of the preceding values.
  • the median powder particle sized can range from 0.05 m to 100 pm, 0.05 pm to 2 pm, 0.3 pm to 30 pm, 1 pm to 50 pm, 3 pm to 50 pm, or 10 pm to 20 pm. In some
  • the median powder particle size can be about 10 pm.
  • the median powder particle size can be determined by, for example, a dynamic light scattering system, as is known in the art.
  • the metal oxyhydroxide material, the metal oxide material, the manganese oxide material, and the molecular sieve material can each be pulverized separately, and then combined to form the filter material.
  • metal oxyhydroxide material, the metal oxide material, the manganese oxide material, and the molecular sieve material can be combined, and then pulverized together to form the filter material.
  • the hydraulic binder can include at least one of: Portland cement, calcium aluminate cement, sulphoaluminate cement, hydroxylapatite, tricalcium phosphate, and fluoaluminate cement.
  • the adsorbent granules can be at or near room temperature during the cementation period. As defined herein, at or near room temperature is from 18° to 30°C.
  • the temperature during the cementation period can be as low as 18°C, 19°C, 20°C, 21 °C, 22°C, or 23°C, or as high as 25°C, 26°C, 27°C, 28°C, 29°C, or 30°C, or any temperature between any two of the preceding temperatures.
  • the temperature during the cementation period can be as low as 18°C, 19°C, 20°C, 21 °C, 22°C, or 23°C, or as high as 25°C, 26°C, 27°C, 28°C, 29°C, or 30°C, or any temperature between any two of the preceding temperatures.
  • the temperature during the cementation period can be as low as 18°C, 19°C, 20°C, 21 °C, 22°C, or 23°C, or as high as 25°C, 26°C, 27°C, 28°C, 29°C, or 30°C, or any temperature between any two of the preceding temperatures.
  • the temperature during the cementation period can be as low
  • temperature during the cementation period can range from 18°C to 30°C, 19°C to 29°C, 20°C to 28°C, 21 °C to 27°C, 22°C to 26°C, or 23°C to 25°C.
  • the water and hydraulic binder chemically react to form mineral hydrates that bind together the filter material, forming hardened adsorbent granules.
  • the cementation period during which the adsorbent granules form sufficient crush strength can be as short as 3 days, 5 days, 7 days, 9 days, 1 1 days, or 13 days, or as long as 17 days, 19 days, 21 days, 23 days, or 25 days, or for any cementation period between any two of the preceding cementation periods.
  • the cementation period can be from 3 days to 25 days, 7 days to 23 days, 9 days to 21 days, 1 1 days to 19 days, 13 days to 17 days, 5 days to 9 days, 5 days to 1 1 days, or 7 days to 17 days.
  • the adsorbent granules can be removed from the sealed container.
  • the adsorbent granules can be washed with additional water after the cementation period.
  • FIG. 1 is a graph illustrating a crush strength of samples from each of three groups of adsorbent granules according to embodiments of the disclosure compared to a crush strength of a samples of a fourth group of adsorbent granules including a clay binder that required high temperature sintering. All four groups of adsorbent granules included the same filter material, as described above.
  • the three groups of adsorbent granules prepared according to embodiments of the disclosure as descried above each included a calcium aluminate cement as the hydraulic binder. For two of the three groups, the hydraulic binder as a weight percentage of the filter material and the hydraulic together was 16.7 wt. %.
  • the hydraulic binder as a weight percentage of the filter material and the hydraulic together was 1 1.1 wt. %.
  • the cementation period for the three groups ranged from 1 1 days to 25 days at room temperature.
  • the fourth group of adsorbent granules included an attapulgite clay binder at 1 1 wt. % of the filter material and the attapulgite clay binder and was sintered at 500°C.
  • the adsorbent granules were spherical and about 2 millimeters in diameter.
  • adsorbent granules from each of the four groups were tested for crush strength.
  • the crush strength was measured with a Particle Strength Tester from Dalian Panghui Keji, Ltd., and an arithmetic mean determined for each group.
  • the results are shown in FIG. 1 .
  • the adsorbent granules including a hydraulic binder according to embodiments of the disclosure exhibited significantly greater crush strengths than the adsorbent granules including the clay binder.
  • the hydraulic binder as a weight percentage of a total weight of the filter material and the hydraulic binder can be as low as 5 wt. %, 6 wt. %, 7 wt. %, 8 wt. %, 9 wt. % or 10 wt. %, or as high as 12 wt. %, 13 wt. %, 14 wt. %, 16 wt. %, 18 wt. %, or 20 wt. %, or between any two of the preceding weight percentages.
  • the hydraulic binder as a weight percentage of the total weight of the filter material and the hydraulic binder can be from 5 wt.
  • the adsorbent granules can further include an organic pore-forming agent (PFA).
  • PFA is an organic compound that is either water soluble or water miscible.
  • the PFA can include at least one of: poly(ethylene glycol), glycerol, glycol, dimethylformamide, and dimethyl sulfoxide.
  • the PFA can include a poly(ethylene glycol) (PEG) having a weight average molecular weight from 100 grams per mole to 4,000 grams per mole.
  • the PFA can include a miscible poly(ethylene glycol) (PEG) having a weight average molecular weight from ranging from 100 grams per mole to 800 grams per mole.
  • the PFA can include PEG-400 which has an average molecular weight of about 400 grams/mole.
  • PEG-400 is a liquid at room temperature and is miscible with water.
  • the PFA can include PEG-2000.
  • PEG-2000 is a solid at room temperature and is soluble in water.
  • a concentration of the PFA in the water can be as low as 5 wt. %, 8 wt. %, 1 1 wt. %, 14 wt. %, 17 wt. %, or 20 wt. % or as high as 26 wt. %, 32 wt. %, 38 wt. %, 44 wt. % or 50 wt. %, or any concentration between any two of the preceding concentrations.
  • the concentration of the PFA in the water can range from 5 wt. % to 50 wt. %, 8 wt. % to 44 wt. %, 1 1 wt. % to 38 wt. %, 14 wt. % to 32 wt. %, 17 wt. % to 26 wt. %, or 20 wt. % to 26 wt. %.
  • the PFA can be combined with the water before the water is combined with the mixture of the filter material and the hydraulic binder as described above.
  • the PFA is present during the granulation and cementing of the adsorbent granules.
  • the adsorbent granules can be washed thoroughly, rinsing away much of the PFA and leaving behind an open pore structure through much of each of the adsorbent granules.
  • the open pore structure can serve to increase the specific surface area of the adsorbent granules.
  • not all of the PFA may be rinsed away, so a residue of the PFA will remain in the adsorbent granules.
  • FIG. 2 is a graph illustrating a specific surface area (Brunauer-Emmett- Teller surface area) of samples from each of two groups of adsorbent granules according to embodiments of this disclosure compared to the specific surface area of samples from each of two other groups of adsorbent granules including a clay binder that required high temperature sintering.
  • a first group of adsorbent granules included a clay binder and was sintered to 500°C.
  • a second group of adsorbent granules also included a clay binder and further included an inorganic PFA.
  • the second group also received an acid wash after being sintered to 500°C to improve pore formation on the surface of the adsorbent granules.
  • a third group of adsorbent granules was made in accordance with embodiments of this disclosure and included a hydraulic binder.
  • a fourth group of adsorbent granules was also made in accordance with embodiments of this disclosure and included an organic pore-forming agent in addition to the hydraulic binder. In all four groups, the binder was present at 1 1 wt. % of the total weight of the filter material and the binder.
  • Adsorbent granules from each of the four groups were measured to determine their specific surface areas per ISO 9277 Determination of the Specific Surface Area of Solids by Gas Adsorption. The results are shown in FIG. 2. As shown in FIG. 2, the adsorbent granules employing a hydraulic binder according to
  • adsorbent granules employing the PFA according to embodiments of the disclosure have the highest specific surface area of the four groups.
  • the organic pore-forming agents can be more homogeneously distributed in the adsorbent granules during granulation.
  • a more homogenous distribution of the PFA in the adsorbent granules may produce more effective pore channels in the adsorbent granules after washing following the
  • Adsorbent granules were prepared by pulverizing 64 g of a filter material mixture including iron oxyhydroxide, titanium dioxide, manganese sand, and zeolite 13X in weight ratios of 1 : 1 :1 :0.6.
  • the filter material mixture was pulverized to a median powder particle size of 10 pm to form a filter material powder.
  • % CaO was mixed together with the filter material powder in a centrifugal mixer (SpeedmixerTM DAC 150.1 FVZ-K from FlacTek Inc., Landrum, South Carolina, U.S.) at 3,000 RPM for 1 minute.
  • a PFA in the form of 100 g of poly(ethylene glycol) having an average molecular weight of about 2,000 g/mole (PEG-2000) was dissolved in 400 g of water to form a 20 wt. % solution. Amounts ranging from 0.5 g to 2 g of the 20 wt.
  • % PEG-2000 solution was sprayed onto the mixture of filter material powder and hydraulic binder in, and granulated in a centrifugal mixer (SpeedmixerTM DAC 150.1 FVZ-K from FlacTek Inc., Landrum, South Carolina, U.S.) at 3,000 RPM for 30 seconds.
  • the process of spraying the 20 wt. % PEG-2000 solution onto the mixture and granulating in the centrifugal mixer for 30 seconds was repeated until 10.8 g of the 20 wt. % PEG-2000 solution had been added to form spherical adsorbent granules.
  • the adsorbent granules were placed in a container and sprayed with from 2 g to 5 g of water. The container was sealed. The adsorbent granules remained in the sealed container for a cementation period of 7 days.
  • the adsorbent granules were washed thoroughly by water to remove much of the PFA to form an open pore structure on the adsorbent granules.
  • the resulting adsorbent granules were about 0.4 mm to 0.8 mm in diameter and contained about 1 1 .1 wt. % of hydraulic binder.
  • the specific area of the adsorbent granules was measured as described above and found to be 157 m 2 /g.
  • the adsorbent granules were tested for crush strength as described above.
  • the adsorbent granules were found to have a crush strength of about 7.8 N.
  • the adsorbent granules were also tested for removal efficiency of arsenic.
  • a sample of adsorbent granules having a volume of 310 milliliters was placed in 550 milliliter filter cartridge.
  • Over 1 ,320 liters of a test solution containing about 100 parts per billion (ppb) of arsenic was passed through the filter cartridge at a rate of 6 liters per hour.
  • the adsorbent granules removed about 90% of the arsenic.
  • Adsorbent granules were prepared by pulverizing 64 g of a filter material mixture including iron oxyhydroxide, titanium dioxide, manganese sand, and zeolite 13X in weight ratios of 1 : 1 :1 :0.6.
  • the filter material mixture was pulverized to a median powder particle size of 10 pm to form a filter material powder.
  • % CaO was mixed together with the filter material powder in a centrifugal mixer (SpeedmixerTM DAC 150.1 FVZ-K from FlacTek Inc., Landrum, South Carolina, U.S.) at 3,000 RPM for 1 minute.
  • a PFA in the form of 100 g of poly(ethylene glycol) having an average molecular weight of about 600 g/mole (PEG-600) was dissolved in 400 g of water to form a 20 wt. % solution. Amounts ranging from 0.5 g to 2 g of the 20 wt.
  • % PEG-600 solution was sprayed onto the mixture of filter material powder and hydraulic binder in, and granulated in a centrifugal mixer (SpeedmixerTM DAC 150.1 FVZ-K from FlacTek Inc., Landrum, South Carolina, U.S.) at 3,000 RPM for 30 seconds.
  • the process of spraying the 20 wt. % PEG-600 solution onto the mixture and granulating in the centrifugal mixer for 30 seconds was repeated until 10.8 g of the 20 wt. % PEG-600 solution had been added to form spherical adsorbent granules.
  • the adsorbent granules were placed in a container and sprayed with from 2 g to 5 g of water. The container was sealed. The adsorbent granules remained in the sealed container for a cementation period of 7 days.
  • the adsorbent granules were washed thoroughly by water to remove much of the PFA to form an open pore structure on the adsorbent granules.
  • the resulting adsorbent granules were about 0.4 mm to 0.8 mm in diameter and contained about 1 1 .1 wt. % of hydraulic binder.
  • the specific area of the adsorbent granules was measured as described above and found to be 181 m 2 /g.
  • the adsorbent granules were tested for crush strength as described above.
  • the adsorbent granules were found to have a crush strength of about 12.5 N.
  • the adsorbent granules were also tested for removal efficiency of arsenic.
  • a sample of adsorbent granules having a volume of 300 milliliters was placed in 550 milliliter filter cartridge.
  • Over 1 ,400 liters of a test solution containing about 100 parts per billion (ppb) of arsenic was passed through the filter cartridge at a rate of 5 liters per hour.
  • the arsenic remaining in the test solution was measured by Inductively Coupled Plasma Mass Spectrometry to determine the percentage of arsenic removed by the adsorbent granules. The results are shown in FIG. 3.
  • FIG. 3 The results are shown in FIG. 3.
  • FIG. 3 shows the outlet arsenic concentration in ppb on the left axis and the removal efficiency on the right axis, each as functions of the volume of test solution passing through the filter cartridge.
  • the adsorbent granules removed more than 90% of the arsenic from the water, and the outlet arsenic concentration was maintained below 10 ppb, which meets the World Health Organization standard for drinking water.

Abstract

A composition of adsorbent granules for the removal of heavy metals from water includes a metal oxyhydroxide material, a metal oxide material, a manganese oxide material, and a hydraulic binder. The adsorbent granules can include a residue of an organic pore-forming agent. A method of making a plurality of adsorbent granules includes granulating a mixture of a filter material, a hydraulic binder, and water, holding the plurality of adsorbent granules in a sealed container at a temperature between 18°C and 30°C for a cementation period, and washing the plurality of adsorbent granules in additional water. The filter material includes a metal oxyhydroxide material, a metal oxide material, and a manganese oxide material. The method can include dissolving a water soluble organic pore-forming agent in the water before granulating the mixture.

Description

ADSORBENT GRANULES FOR REMOVAL OF HEAVY METALS AND METHOD OF
MAKING
FIELD
[0001] The present invention relates to adsorbents for water purification. More specifically, the present invention relates to adsorbents for removal of heavy metals from water and methods for making adsorbents for removal of heavy metals from water.
BACKGROUND
[0002] Heavy metals, for example, arsenic (As), lead (Pb), cadmium (Cd) and mercury (Hg), may be found in harmful concentrations in some drinking water. The sources of the heavy metals may be naturally occurring or result from industrial pollution. The heavy metals can be removed by a number of techniques including reverse osmosis or distillation. However, these techniques can be costly because they can be energy and resource intensive.
[0003] A less costly method of heavy metal removal can be the filtration of water through a cartridge containing a granular adsorbent that is designed to remove heavy metals. However, such granular adsorbents may not be able to remove heavy metals with great efficiency, resulting in larger and more costly filter cartridges.
SUMMARY
[0004] A composition of adsorbent granules for the removal of heavy metals from water includes a metal oxyhydroxide material, a metal oxide material, a
manganese oxide material, and a hydraulic binder. The adsorbent granules can include an organic pore-forming agent. A method of making a plurality of adsorbent granules includes mixing together a filter material and a hydraulic binder, combining the mixture of the filter material and the hydraulic binder with water to form a paste, granulating the paste to form the plurality of adsorbent granules, applying additional water to the surface of each of the plurality of adsorbent granules, holding the plurality of adsorbent granules in a sealed container at a temperature between 18°C and 30°C for a cementation period, and washing the plurality of adsorbent granules in additional water. The filter material includes a metal oxyhydroxide material, a metal oxide material, and a manganese oxide material. The method can include dissolving a pore-forming agent in the water before combining the mixture of the filter material and the hydraulic binder with the water to form the paste. The pore-forming agent includes an organic compound that is water soluble or water miscible.
[0005] Various embodiments concern a composition of adsorbent granules for the removal of heavy metals from water. Each of the plurality of adsorbent granules includes a metal oxyhydroxide material, a metal oxide material, a manganese oxide material, and a hydraulic binder. In some embodiments, the hydraulic binder includes at least one of: Portland cement, calcium aluminate cement, sulphoaluminate cement, hydroxylapatite, tricalcium phosphate, and fluoaluminate cement. In some
embodiments, the hydraulic binder is from 5 wt. % to 20 wt. % of the composition. In some embodiments, the hydraulic binder is from 10 wt. % to 12 wt. % of the
composition. In some embodiments, each of the plurality of adsorbent granules further includes a molecular sieve material. In some embodiments, a ratio of the metal oxyhydroxide material to the metal oxide material to the manganese oxide material to the molecular sieve material is 0.5-2 to 0.5-2 to 0.5-2 to 0.01 -1. In some embodiments, each of the plurality of adsorbent granules further includes a residue of a pore-forming agent, the pore-forming agent including an organic compound that is water soluble or water miscible. In some particular embodiments, the pore-forming agent includes at least one of: poly(ethylene glycol), glycerol, glycol, dimethylformamide, and dimethyl sulfoxide. In some particular embodiments, the pore-forming agent includes
poly(ethylene glycol) with a weight average molecular weight from 100 grams/mole to 4,000 grams/mole. In some embodiments, the metal oxyhydroxide material includes iron oxyhydroxide, the metal oxide material includes titanium dioxide, and the
manganese oxide material includes manganese sand.
[0006] Various embodiments concern a method of making a plurality of adsorbent granules. The method includes mixing together a filter material and a hydraulic binder, combining the mixture of the filter material and the hydraulic binder with water to form a paste, granulating the paste to form the plurality of adsorbent granules, applying additional water to a surface of each of the plurality of adsorbent granules, holding the plurality of adsorbent granules in a sealed container at a temperature between 18°C and 30°C for a cementation period, and washing the plurality of adsorbent granules in additional water. The filter material includes a metal oxyhydroxide material, a metal oxide material, and a manganese oxide material. In some embodiments, the hydraulic binder includes at least one of: Portland cement, calcium aluminate cement,
sulphoaluminate cement, hydroxylapatite, tricalcium phosphate, and fluoaluminate cement. In some embodiments, the hydraulic binder is from 5 wt. % to 20 wt. % of a total weight of the filter material and the hydraulic binder. In some particular
embodiments, the hydraulic binder is from 10 wt. % to 12 wt. % of a total weight of the filter material and the hydraulic binder. In some embodiments, the metal oxyhydroxide material includes iron oxyhydroxide, the metal oxide material includes titanium dioxide, and the manganese oxide material includes manganese sand. In some embodiments, the filter material further includes a molecular sieve material. In some particular embodiments, a ratio of the metal oxyhydroxide material to the metal oxide material to the manganese oxide material to the molecular sieve material is 0.5-2 to 0.5-2 to 0.5-2 to 0.01 -1. In some embodiments, the method further includes dissolving a pore-forming agent in the water before combining the mixture of the filter material and the hydraulic binder with the water to form the paste, the pore-forming agent including an organic compound that is water soluble or water miscible. In some particular embodiments, the pore-forming agent includes at least one of: poly(ethylene glycol), glycerol, glycol, dimethylformamide, and dimethyl sulfoxide. In some particular embodiments, the pore- forming agent includes poly(ethylene glycol) with a weight average molecular weight from 100 grams/mole to 4,000 grams/mole.
[0007] The above mentioned and other features of the invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a graph illustrating a crush strength of samples from each of three groups of adsorbent granules according to embodiments of the disclosure compared to a crush strength of a samples of a fourth group of adsorbent granules including a clay binder that required high temperature sintering.
[0009] FIG. 2 is a graph illustrating a specific surface area (Brunauer-Emmett- Teller surface area) of samples from each of two groups of adsorbent granules according to embodiments of this disclosure compared to the specific surface area of samples from each of two other groups of adsorbent granules including a clay binder that required high temperature sintering.
[0010] FIG. 3 is a graph illustrating arsenic removal efficiency of adsorbent granules, according to embodiments of this disclosure.
DETAILED DESCRIPTION
[0011] Adsorbent granules for use in adsorbing heavy metals from water are often made of a combination of filter materials held together with clay binders. The filter materials can be pulverized into a fine powder, mixed together with the binder, and then formed into adsorbent granules sized for use in, for example, a filter cartridge for household applications. The synergistic combination of the filter materials in close proximity can result in greater than 90% efficiency in removal of at least some heavy metals. The filter materials can include a metal oxyhydroxide material, such as iron oxyhydroxide (FeOOH), which is a highly effective in adsorbing heavy metals, such as arsenic.
[0012] The binder holds the filter materials together to provide an adsorbent granule with a crush strength of at least 7 Newtons (N) to be able to withstand the rigors of manufacturing and handling associated with the fabrication and use of filter cartridges. In order to develop such a high level of crush strength, adsorbent granules using clay binders must be sintered, or calcined, at temperatures as high as 400°C to 800°C However, FeOOH is thermally unstable and will tend to convert to ferric oxide (Fe2O3) at temperatures above 150°C, according to its thermogravimetric analysis (TGA) curve. This conversion can reduce the removal efficiency of the filter material to as low as 60% because Fe203 is not as effective in adsorbing heavy metals as FeOOH.
[0013] Adsorbent granules according to embodiments of this disclosure employ hydraulic binders. Hydraulic binders are materials that chemically react with water to set and harden. Hydraulic binders can cement or bind together the filter materials at or near room temperature. Hydraulic binders do not require high temperatures to impart the desired strength to the adsorbent granules. Adsorbent granules including a hydraulic binder can exhibit a higher removal efficiency compared to adsorbent granules including a clay binder which much be exposed to high temperatures. Without wishing to be bound to any theory, it is believed that because the adsorbent granules including the hydraulic binder are not exposed to high temperatures, more of the metal oxyhydroxide is preserved for used in filtering heavy metals from water. In some embodiments, heavy metal removal efficiency is further enhanced by the use of a water soluble or water miscible organic pore-forming agent to increase the specific surface area of the adsorbent granules. Such adsorbent granules can further include a residue of the organic pore-forming agent.
[0014] Embodiments of the disclosure include a method for making the adsorbent granules that includes applying water to the adsorbent granules including the hydraulic binder and holding them in a sealed container at or near room temperature for a period of time to permit the binder to cement the filter materials together. The method provides for the formation of adsorbent granules of sufficient crush strength without the use of high temperature sintering. In some embodiments, heavy metal removal efficiency is further enhanced by adding a water soluble or water miscible organic pore- forming agent to the adsorbent granules. The pore-forming agent is present during the granulation and cementing of the adsorbent granules, and then much of it is rinsed away after the cementing, leaving an open pore structure through much of each of the adsorbent granules, increasing the specific surface area of the adsorbent granules.
[0015] In some embodiments, the adsorbent granules can be formed by mixing together a filter material and a hydraulic binder, and then combining the mixture with water to form a paste. The paste can be granulated to form the adsorbent granules. Some techniques used for granulating include compaction granulation, centrifugal granulation, melting granulation, spraying granulation, and extrusion pelletizing, as are known in the art.
[0016] The filter material can include a metal oxyhydroxide material, a metal oxide material, and a manganese oxide material. The metal oxyhydroxide material can include, for example, an iron oxyhydroxide (FeO(OH)) or a titanium oxyhydroxide (TiO(OH)). The metal oxide material can include, for example, titanium dioxide (T1O2), ferrous oxide (FeO), or ferric oxide (Fe2O3). The manganese oxide (MnO) material can be in the form of, for example, a manganese sand material. In some embodiments, the filter material powder can further include a molecular sieve material, such as, for example, activated alumina, or a zeolite, such as zeolite 13X.
[0017] In some embodiments, the weight ratios of the metal oxyhydroxide material to the metal oxide material to the manganese oxide material to the molecular sieve material can range from 0.5-2 to 0.5-2 to 0.5-2 to 0.01 -1 . In some embodiments, the weight ratios of the metal oxyhydroxide material to the metal oxide material to the manganese oxide material to the molecular sieve material can be 1 to 1 to 1 to 0.6, otherwise expressed as: 1 : 1 : 1 :0.6.
[0018] In some embodiments, the weight of the metal oxyhydroxide material as a percentage of the total weight of the filter material powder can be as low as 2 wt. %, 5 wt. %, or 10 wt. %, or as high as 30 wt. %, 60 wt. %, or 90 wt. %, or be any weight percentage between any two of the preceding weight percentages. For example, in some embodiments, the weight of the metal oxyhydroxide material as a percentage of the total weight of the filter material powder can range from 2 wt. % to 90 wt.%, 5 wt. % to 60 wt.%, or 10 wt. % to 30 wt.%.
[0019] In some embodiments, the weight of the metal oxide material as a percentage of the total weight of the filter material powder can be as low as 2 wt. %, 5 wt. %, or 10 wt. %, or as high as 30 wt. %, 60 wt. %, or 90 wt. %, or be any weight percentage between any two of the preceding weight percentages. For example, in some embodiments, the weight of the metal oxide material as a percentage of the total weight of the filter material powder can range from 2 wt. % to 90 wt.%, 5 wt. % to 60 wt.%, or 10 wt. % to 30 wt.%. [0020] In some embodiments, the weight of the manganese oxide material as a percentage of the total weight of the filter material powder can be as 2 wt. %, 5 wt. %, or 10 wt. %, or as high as 30 wt. %, 60 wt. %, or 90 wt. %, or be any weight percentage between any two of the preceding weight percentages. For example, in some
embodiments, the weight of the manganese oxide material as a percentage of the total weight of the filter material powder can range from 2 wt. % to 90 wt.%, 5 wt. % to 60 wt.%, or 10 wt. % to 30 wt.%.
[0001] In some embodiments, the weight of the molecular sieve material as a percentage of the total weight of the filter material powder can be as low as 0.5 wt. %, 2 wt. %, or 5 wt. %, or as high as 10 wt. %, 20 wt. %, or 30 wt. %, or be any weight percentage between any two of the preceding weight percentages. For example, in some embodiments, the weight of the molecular sieve material as a percentage of the total weight of the filter material powder can range from 0.5 wt. % to 30 wt.%, 2 wt. % to 20 wt.%, or 5 wt. % to 10 wt.%.
[0002] The metal oxyhydroxide material, the metal oxide material, the
manganese oxide material, and the molecular sieve material can each be pulverized to form the filter material. The filter material can be in the form of a fine powder having a median powder particle size as small as 0.05 microns (pm), 0.1 pm, 0.2 pm, 0.3 pm, 0.5 pm, 1 pm, or 2 pm, or as large as 3 pm, 5 pm, 10 pm, 20 pm, 30 pm, 50 pm, or 100 pm, or between any two of the preceding values. For example, in some embodiments, the median powder particle sized can range from 0.05 m to 100 pm, 0.05 pm to 2 pm, 0.3 pm to 30 pm, 1 pm to 50 pm, 3 pm to 50 pm, or 10 pm to 20 pm. In some
embodiments, the median powder particle size can be about 10 pm. The median powder particle size can be determined by, for example, a dynamic light scattering system, as is known in the art. In some embodiments, the metal oxyhydroxide material, the metal oxide material, the manganese oxide material, and the molecular sieve material can each be pulverized separately, and then combined to form the filter material. In some other embodiments, metal oxyhydroxide material, the metal oxide material, the manganese oxide material, and the molecular sieve material can be combined, and then pulverized together to form the filter material. [0003] The hydraulic binder can include at least one of: Portland cement, calcium aluminate cement, sulphoaluminate cement, hydroxylapatite, tricalcium phosphate, and fluoaluminate cement.
[0004] After granulation, additional water can be applied to the surface of each of the adsorbent granules and then the moistened adsorbent granules can be sealed in a container for a cementation period. In some embodiments, the adsorbent granules can be at or near room temperature during the cementation period. As defined herein, at or near room temperature is from 18° to 30°C. In some embodiments, the temperature during the cementation period can be as low as 18°C, 19°C, 20°C, 21 °C, 22°C, or 23°C, or as high as 25°C, 26°C, 27°C, 28°C, 29°C, or 30°C, or any temperature between any two of the preceding temperatures. For example, in some embodiments, the
temperature during the cementation period can range from 18°C to 30°C, 19°C to 29°C, 20°C to 28°C, 21 °C to 27°C, 22°C to 26°C, or 23°C to 25°C.
[0005] During the cementation period, the water and hydraulic binder chemically react to form mineral hydrates that bind together the filter material, forming hardened adsorbent granules. The cementation period during which the adsorbent granules form sufficient crush strength can be as short as 3 days, 5 days, 7 days, 9 days, 1 1 days, or 13 days, or as long as 17 days, 19 days, 21 days, 23 days, or 25 days, or for any cementation period between any two of the preceding cementation periods. For example, in some embodiments, the cementation period can be from 3 days to 25 days, 7 days to 23 days, 9 days to 21 days, 1 1 days to 19 days, 13 days to 17 days, 5 days to 9 days, 5 days to 1 1 days, or 7 days to 17 days. After the cementation period, the adsorbent granules can be removed from the sealed container. In some embodiments, the adsorbent granules can be washed with additional water after the cementation period.
[0006] FIG. 1 is a graph illustrating a crush strength of samples from each of three groups of adsorbent granules according to embodiments of the disclosure compared to a crush strength of a samples of a fourth group of adsorbent granules including a clay binder that required high temperature sintering. All four groups of adsorbent granules included the same filter material, as described above. The three groups of adsorbent granules prepared according to embodiments of the disclosure as descried above each included a calcium aluminate cement as the hydraulic binder. For two of the three groups, the hydraulic binder as a weight percentage of the filter material and the hydraulic together was 16.7 wt. %. For the third of the three groups, the hydraulic binder as a weight percentage of the filter material and the hydraulic together was 1 1.1 wt. %. The cementation period for the three groups ranged from 1 1 days to 25 days at room temperature. The fourth group of adsorbent granules included an attapulgite clay binder at 1 1 wt. % of the filter material and the attapulgite clay binder and was sintered at 500°C. The adsorbent granules were spherical and about 2 millimeters in diameter.
[0007] Twenty adsorbent granules from each of the four groups were tested for crush strength. The crush strength was measured with a Particle Strength Tester from Dalian Panghui Keji, Ltd., and an arithmetic mean determined for each group. The results are shown in FIG. 1 . As shown in FIG. 1 , the adsorbent granules including a hydraulic binder according to embodiments of the disclosure exhibited significantly greater crush strengths than the adsorbent granules including the clay binder.
[0008] Thus, in some embodiments, the hydraulic binder as a weight percentage of a total weight of the filter material and the hydraulic binder can be as low as 5 wt. %, 6 wt. %, 7 wt. %, 8 wt. %, 9 wt. % or 10 wt. %, or as high as 12 wt. %, 13 wt. %, 14 wt. %, 16 wt. %, 18 wt. %, or 20 wt. %, or between any two of the preceding weight percentages. For example, in some embodiments, the hydraulic binder as a weight percentage of the total weight of the filter material and the hydraulic binder can be from 5 wt. % to 20 wt. %, 6 wt. % to 18 wt. %, 7 wt. % to 16 wt. %, 8 wt. % to 14 wt. %, 9 wt. % to 13 wt. %, or 10 wt. % to 12 wt. %.
[0009] In some embodiments, the adsorbent granules can further include an organic pore-forming agent (PFA). The PFA is an organic compound that is either water soluble or water miscible. In some embodiments, the PFA can include at least one of: poly(ethylene glycol), glycerol, glycol, dimethylformamide, and dimethyl sulfoxide. In some embodiments, the PFA can include a poly(ethylene glycol) (PEG) having a weight average molecular weight from 100 grams per mole to 4,000 grams per mole. In some embodiments, the PFA can include a miscible poly(ethylene glycol) (PEG) having a weight average molecular weight from ranging from 100 grams per mole to 800 grams per mole. For example, in some embodiments, the PFA can include PEG-400 which has an average molecular weight of about 400 grams/mole. PEG-400 is a liquid at room temperature and is miscible with water. In other embodiments, the PFA can include PEG-2000. PEG-2000 is a solid at room temperature and is soluble in water.
[0010] In some embodiments, a concentration of the PFA in the water can be as low as 5 wt. %, 8 wt. %, 1 1 wt. %, 14 wt. %, 17 wt. %, or 20 wt. % or as high as 26 wt. %, 32 wt. %, 38 wt. %, 44 wt. % or 50 wt. %, or any concentration between any two of the preceding concentrations. For example, in some embodiments, the concentration of the PFA in the water can range from 5 wt. % to 50 wt. %, 8 wt. % to 44 wt. %, 1 1 wt. % to 38 wt. %, 14 wt. % to 32 wt. %, 17 wt. % to 26 wt. %, or 20 wt. % to 26 wt. %.
[0011] The PFA can be combined with the water before the water is combined with the mixture of the filter material and the hydraulic binder as described above.
Thus, the PFA is present during the granulation and cementing of the adsorbent granules. After the cementation period, the adsorbent granules can be washed thoroughly, rinsing away much of the PFA and leaving behind an open pore structure through much of each of the adsorbent granules. The open pore structure can serve to increase the specific surface area of the adsorbent granules. In some embodiments, not all of the PFA may be rinsed away, so a residue of the PFA will remain in the adsorbent granules.
[0012] FIG. 2 is a graph illustrating a specific surface area (Brunauer-Emmett- Teller surface area) of samples from each of two groups of adsorbent granules according to embodiments of this disclosure compared to the specific surface area of samples from each of two other groups of adsorbent granules including a clay binder that required high temperature sintering. A first group of adsorbent granules included a clay binder and was sintered to 500°C. A second group of adsorbent granules also included a clay binder and further included an inorganic PFA. The second group also received an acid wash after being sintered to 500°C to improve pore formation on the surface of the adsorbent granules. A third group of adsorbent granules was made in accordance with embodiments of this disclosure and included a hydraulic binder. A fourth group of adsorbent granules was also made in accordance with embodiments of this disclosure and included an organic pore-forming agent in addition to the hydraulic binder. In all four groups, the binder was present at 1 1 wt. % of the total weight of the filter material and the binder.
[0013] Adsorbent granules from each of the four groups were measured to determine their specific surface areas per ISO 9277 Determination of the Specific Surface Area of Solids by Gas Adsorption. The results are shown in FIG. 2. As shown in FIG. 2, the adsorbent granules employing a hydraulic binder according to
embodiment of the disclosure have significantly larger specific surfaces than those produced with clay binders. Further, adsorbent granules employing the PFA according to embodiments of the disclosure have the highest specific surface area of the four groups. Without wishing to be bound by any theory, it is believed that when compared with inorganic pore-forming agents, the organic pore-forming agents can be more homogeneously distributed in the adsorbent granules during granulation. A more homogenous distribution of the PFA in the adsorbent granules may produce more effective pore channels in the adsorbent granules after washing following the
cementation period.
EXAMPLES
Example 1
[0014] Adsorbent granules were prepared by pulverizing 64 g of a filter material mixture including iron oxyhydroxide, titanium dioxide, manganese sand, and zeolite 13X in weight ratios of 1 : 1 :1 :0.6. The filter material mixture was pulverized to a median powder particle size of 10 pm to form a filter material powder. A hydraulic binder of 8 g of calcium aluminate cement (CA-70, 70 wt. % AI2O3, 30 wt. % CaO) was mixed together with the filter material powder in a centrifugal mixer (Speedmixer™ DAC 150.1 FVZ-K from FlacTek Inc., Landrum, South Carolina, U.S.) at 3,000 RPM for 1 minute. A PFA in the form of 100 g of poly(ethylene glycol) having an average molecular weight of about 2,000 g/mole (PEG-2000) was dissolved in 400 g of water to form a 20 wt. % solution. Amounts ranging from 0.5 g to 2 g of the 20 wt. % PEG-2000 solution was sprayed onto the mixture of filter material powder and hydraulic binder in, and granulated in a centrifugal mixer (Speedmixer™ DAC 150.1 FVZ-K from FlacTek Inc., Landrum, South Carolina, U.S.) at 3,000 RPM for 30 seconds. The process of spraying the 20 wt. % PEG-2000 solution onto the mixture and granulating in the centrifugal mixer for 30 seconds was repeated until 10.8 g of the 20 wt. % PEG-2000 solution had been added to form spherical adsorbent granules. The adsorbent granules were placed in a container and sprayed with from 2 g to 5 g of water. The container was sealed. The adsorbent granules remained in the sealed container for a cementation period of 7 days.
[0001] After the cementation period, the adsorbent granules were washed thoroughly by water to remove much of the PFA to form an open pore structure on the adsorbent granules. The resulting adsorbent granules were about 0.4 mm to 0.8 mm in diameter and contained about 1 1 .1 wt. % of hydraulic binder. The specific area of the adsorbent granules was measured as described above and found to be 157 m2/g. The adsorbent granules were tested for crush strength as described above. The adsorbent granules were found to have a crush strength of about 7.8 N.
[0002] The adsorbent granules were also tested for removal efficiency of arsenic. A sample of adsorbent granules having a volume of 310 milliliters was placed in 550 milliliter filter cartridge. Over 1 ,320 liters of a test solution containing about 100 parts per billion (ppb) of arsenic was passed through the filter cartridge at a rate of 6 liters per hour. The adsorbent granules removed about 90% of the arsenic.
Example 2
[0003] Adsorbent granules were prepared by pulverizing 64 g of a filter material mixture including iron oxyhydroxide, titanium dioxide, manganese sand, and zeolite 13X in weight ratios of 1 : 1 :1 :0.6. The filter material mixture was pulverized to a median powder particle size of 10 pm to form a filter material powder. A hydraulic binder of 8 g of calcium aluminate cement (CA-70, 70 wt. % AI2O3, 30 wt. % CaO) was mixed together with the filter material powder in a centrifugal mixer (Speedmixer™ DAC 150.1 FVZ-K from FlacTek Inc., Landrum, South Carolina, U.S.) at 3,000 RPM for 1 minute. A PFA in the form of 100 g of poly(ethylene glycol) having an average molecular weight of about 600 g/mole (PEG-600) was dissolved in 400 g of water to form a 20 wt. % solution. Amounts ranging from 0.5 g to 2 g of the 20 wt. % PEG-600 solution was sprayed onto the mixture of filter material powder and hydraulic binder in, and granulated in a centrifugal mixer (Speedmixer™ DAC 150.1 FVZ-K from FlacTek Inc., Landrum, South Carolina, U.S.) at 3,000 RPM for 30 seconds. The process of spraying the 20 wt. % PEG-600 solution onto the mixture and granulating in the centrifugal mixer for 30 seconds was repeated until 10.8 g of the 20 wt. % PEG-600 solution had been added to form spherical adsorbent granules. The adsorbent granules were placed in a container and sprayed with from 2 g to 5 g of water. The container was sealed. The adsorbent granules remained in the sealed container for a cementation period of 7 days.
[0004] After the cementation period, the adsorbent granules were washed thoroughly by water to remove much of the PFA to form an open pore structure on the adsorbent granules. The resulting adsorbent granules were about 0.4 mm to 0.8 mm in diameter and contained about 1 1 .1 wt. % of hydraulic binder. The specific area of the adsorbent granules was measured as described above and found to be 181 m2/g. The adsorbent granules were tested for crush strength as described above. The adsorbent granules were found to have a crush strength of about 12.5 N.
[0005] The adsorbent granules were also tested for removal efficiency of arsenic. A sample of adsorbent granules having a volume of 300 milliliters was placed in 550 milliliter filter cartridge. Over 1 ,400 liters of a test solution containing about 100 parts per billion (ppb) of arsenic was passed through the filter cartridge at a rate of 5 liters per hour. The arsenic remaining in the test solution was measured by Inductively Coupled Plasma Mass Spectrometry to determine the percentage of arsenic removed by the adsorbent granules. The results are shown in FIG. 3. FIG. 3 shows the outlet arsenic concentration in ppb on the left axis and the removal efficiency on the right axis, each as functions of the volume of test solution passing through the filter cartridge. As shown in FIG. 3, the adsorbent granules removed more than 90% of the arsenic from the water, and the outlet arsenic concentration was maintained below 10 ppb, which meets the World Health Organization standard for drinking water.
[0006] While this invention has been described as relative to exemplary designs, the present invention may be further modified within the spirit and scope of this disclosure. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.

Claims

CLAIMS What is claimed is:
1 . A composition of adsorbent granules for the removal of heavy metals from water, each of the plurality of adsorbent granules comprising:
a metal oxyhydroxide material;
a metal oxide material;
a manganese oxide material; and
a hydraulic binder.
2. The composition of claim 1 , wherein the hydraulic binder includes at least one of: Portland cement, calcium aluminate cement, sulphoaluminate cement, hydroxylapatite, tricalcium phosphate, and fluoaluminate cement.
3. The composition of claim 1 , wherein the hydraulic binder is from 5 wt. % to 20 wt. % of the composition.
4. The composition of claim 1 , wherein each of the plurality of adsorbent granules further includes a molecular sieve material.
5. The composition of claim 4, wherein a ratio of the metal oxyhydroxide material to the metal oxide material to the manganese oxide material to the molecular sieve material is 0.5-2 to 0.5-2 to 0.5-2 to 0.01 -1 .
6. The composition of claim 1 , wherein each of the plurality of adsorbent granules further includes a residue of a pore-forming agent, the pore-forming agent including an organic compound that is water soluble or water miscible.
7. The composition of claim 6, wherein the pore-forming agent includes poly(ethylene glycol) with a weight average molecular weight from 100 grams/mole to 4,000 grams/mole.
8. The composition of claim 1 , wherein the metal oxyhydroxide material includes iron oxyhydroxide, the metal oxide material includes titanium dioxide, and the
manganese oxide material includes manganese sand.
9. A method of making a plurality of adsorbent granules, the method comprising: mixing together a filter material and a hydraulic binder, the filter material including a metal oxyhydroxide material, a metal oxide material, and a manganese oxide material;
combining the mixture of the filter material and the hydraulic binder with water to form a paste;
granulating the paste to form the plurality of adsorbent granules;
applying additional water to a surface of each of the plurality of adsorbent
granules;
holding the plurality of adsorbent granules in a sealed container at a temperature between 18°C and 30°C for a cementation period; and
washing the plurality of adsorbent granules in additional water.
10. The method of claim 9, wherein the hydraulic binder includes at least one of: Portland cement, calcium aluminate cement, sulphoaluminate cement, hydroxylapatite, tricalcium phosphate, and fluoaluminate cement.
1 1 . The method of claim 9, wherein the hydraulic binder is from 5 wt. % to 20 wt. % of a total weight of the filter material and the hydraulic binder.
12. The method of claim 9, wherein the filter material further includes a molecular sieve material.
13. The method of claim 12, wherein a ratio of the metal oxyhydroxide material to the metal oxide material to the manganese oxide material to the molecular sieve material is 0.5-2 to 0.5-2 to 0.5-2 to 0.01 -1.
14. The method of claim 9, further including dissolving a pore-forming agent in the water before combining the mixture of the filter material and the hydraulic binder with the water to form the paste, the pore-forming agent including an organic compound that is water soluble or water miscible.
15. The method of claim 14, wherein the pore-forming agent includes poly(ethylene glycol) with a weight average molecular weight from 100 grams/mole to 4,000 grams/mole.
PCT/US2018/051654 2017-09-22 2018-09-19 Adsorbent granules for removal of heavy metals and method of making WO2019060358A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201710866948.9A CN109529789A (en) 2017-09-22 2017-09-22 Absorbent particles and preparation method thereof for removing heavy metal
CN201710866948.9 2017-09-22

Publications (1)

Publication Number Publication Date
WO2019060358A1 true WO2019060358A1 (en) 2019-03-28

Family

ID=65809870

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2018/051654 WO2019060358A1 (en) 2017-09-22 2018-09-19 Adsorbent granules for removal of heavy metals and method of making

Country Status (2)

Country Link
CN (1) CN109529789A (en)
WO (1) WO2019060358A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111921496A (en) * 2020-07-10 2020-11-13 广东石油化工学院 Composite adsorbent and preparation method and application thereof

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110314644A (en) * 2019-07-24 2019-10-11 西安建筑科技大学 A kind of sulphate aluminium cement-bentonite composite material and its preparation method and application for adsorbing heavy metal ion
CN110452703A (en) * 2019-08-28 2019-11-15 孙毅 One heavy metal species normal temperature cure agent and the method for using heavy metal in its curing heavy metal pollutant
KR102653354B1 (en) * 2021-12-22 2024-03-29 한국광해광업공단 Manufacturing method of bead-type arsenic adsorbent using iron hydroxide-based waste

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997017307A2 (en) * 1995-11-06 1997-05-15 Aeci Limited Method for preparing hardened granules from a particulate material
US20030153457A1 (en) * 2000-06-19 2003-08-14 Yasushi Nemoto Adsorbents, process for producing the same, and applications thereof
US20030209495A1 (en) * 2002-03-12 2003-11-13 Andreas Schlegel Mixtures of adsorber materials
CN102580701A (en) * 2012-01-18 2012-07-18 西安蓝晓科技新材料股份有限公司 Preparation method of arsenic removal resin
CN103649349A (en) * 2011-05-10 2014-03-19 凯米罗总公司 Methods for removing contaminants from aqueous systems

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997017307A2 (en) * 1995-11-06 1997-05-15 Aeci Limited Method for preparing hardened granules from a particulate material
US20030153457A1 (en) * 2000-06-19 2003-08-14 Yasushi Nemoto Adsorbents, process for producing the same, and applications thereof
US20030209495A1 (en) * 2002-03-12 2003-11-13 Andreas Schlegel Mixtures of adsorber materials
CN103649349A (en) * 2011-05-10 2014-03-19 凯米罗总公司 Methods for removing contaminants from aqueous systems
CN102580701A (en) * 2012-01-18 2012-07-18 西安蓝晓科技新材料股份有限公司 Preparation method of arsenic removal resin

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111921496A (en) * 2020-07-10 2020-11-13 广东石油化工学院 Composite adsorbent and preparation method and application thereof

Also Published As

Publication number Publication date
CN109529789A (en) 2019-03-29

Similar Documents

Publication Publication Date Title
WO2019060358A1 (en) Adsorbent granules for removal of heavy metals and method of making
Tian et al. Immobilization of cesium in fly ash-silica fume based geopolymers with different Si/Al molar ratios
CN1443600B (en) Adsorbent mixture
CN108463445B (en) Composition comprising chromium-depleted modified red mud and method of making same
KR101334533B1 (en) sludge solidification removal composite and using the covering landfill production method
Visa et al. Concurrent dyes adsorption and photo-degradation on fly ash based substrates
EP1651580A1 (en) Granulate made of sintered or cellular broken glass
Mondal et al. Structure–property relationship of geopolymers for aqueous Pb removal
Ni et al. A critical review on adsorption and recovery of fluoride from wastewater by metal-based adsorbents
US20200338526A1 (en) Sorbents from iron-rich and aluminium-rich starting materials
JP2007098364A (en) Adsorbing material
JP5037950B2 (en) Water purification agent and method for producing the same
JPWO2004078374A1 (en) Soil conditioner
WO2019060361A1 (en) Adsorbent granules for removal of heavy metals and method of making
KR102230941B1 (en) Method for manufacturing a porous composite for treating contaminated water using waste sludge, a porous composite manufactured therefrom
JP2008259942A (en) Boron adsorbent material and method for manufacturing the same
JP2023025362A (en) Harmful substance treatment agent and method for treating harmful substance-containing waste water
CN112108110A (en) Nitrogen and phosphorus removal granular material based on natural zeolite and preparation method thereof
CN105771883A (en) Forsterite adsorbent for sewage treatment and preparation method thereof
Li et al. Synthesis and behavior of a magnetic composite based on crushed autoclaved aerated concrete for low-concentration phosphate removal
RU2592525C2 (en) Sorbent for cleaning aqueous media from heavy metals and preparation method thereof
KR102261298B1 (en) Carbon Block composition for Filter of water purifier and Carbon Block for Filter of water purifier manufactured by comprising the same
JPH10211428A (en) Adsorptive ceramic
CA3227469A1 (en) A scalable and sustainable process for transforming incineration bottom ash into useable aggregates
AU2021348256A1 (en) Filter material for soil filters for phosphate adsorption

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18857671

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18857671

Country of ref document: EP

Kind code of ref document: A1