Use of MgO doped with a divalent or trivalent metal cation for removing arsenic from water

Patent metadata

Field	Value
Publication number	US-9663389-B1
Application number	US-201313964424-A
Country	US
Kind code	B1
Filing date	Aug 12, 2013
Priority date	Dec 17, 2008
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

Systems and methods for use of magnesium hydroxide, either directly or through one or more precursors, doped with a divalent or trivalent metal cation, for removing arsenic from drinking water, including water distribution systems. In one embodiment, magnesium hydroxide, Mg(OH) 2 (a strong adsorbent for arsenic) doped with a divalent or trivalent metal cation is used to adsorb arsenic. The complex consisting of arsenic adsorbed on Mg(OH) 2 doped with a divalent or trivalent metal cation is subsequently removed from the water by conventional means, including filtration, settling, skimming, vortexing, centrifugation, magnetic separation, or other well-known separation systems. In another embodiment, magnesium oxide, MgO, is employed, which reacts with water to form Mg(OH) 2 . The resulting Mg(OH) 2 doped with a divalent or trivalent metal cation, then adsorbs arsenic, as set forth above. The method can also be used to treat human or animal poisoning with arsenic.

First claim

What is claimed is:

1. A composition of matter, comprising:
particles of MgO or Mg(OH) 2 having a zinc coating;
wherein the median particle size is less than 3 microns; and
wherein the zinc coating is present as any one of zinc sulfate, hydrous zinc sulfate, zinc chloride, zinc nitrate, and anhydrous zinc nitrate.

2. The composition of claim 1 , wherein the zinc coating is 5% of the mass of the MgO or Mg(OH) 2 coated particles.

3. The composition of claim 1 , wherein the particles have a diameter of between 0.5 and 1.0 microns.

Assignees

• Sandia Corp

Inventors

• Moore Robert C
• Larese Kathleen Caroline
• Bontchev Ranko Panayotov

Classifications

• C02F1/281

  using inorganic sorbents · CPC title

• B01J20/3204

  Inorganic carriers, supports or substrates · CPC title

• B01J20/041

  Oxides or hydroxides · CPC title

• C02F2101/103

  Arsenic compounds · CPC title

• C02F1/62 Primary

  Heavy metal compounds · CPC title