Carbon dioxide enhanced complex-adsorption process for metal or metalloid removal from water
AssigneeCH2M Hill, Inc.
InventorJoseph Daniel Chwirka
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Abstract
A method of removing metal or metalloids, arsenic in particular, from groundwater or another source of contaminated water. The method comprises providing a water source, contacting the water source with CO2, whereby the pH of the water source is lowered to produce pretreated water, contacting the pretreated water with a metal or metalloid complex-adsorbing substance whereby contaminants are separated from the remainder of the pretreated water to produce metal or metalloid-depleted water, and stripping the CO2 from the metal or metalloid-depleted water, whereby the pH of metal or metalloid-depleted water is increased. A system for metal removal utilizing the CO2 process is also provided.
Claims34
A method of removing a metal or a metalloid from water comprising:
- providing water containing a metal or a metalloid from a source;
- contacting the water with carbon dioxide whereby the pH of the water is lowered producing pre-treated water;
- contacting the pre-treated water with a metal or metalloid complex-adsorbing substance to produce a metal or metalloid depleted water;
- and
- stripping the carbon dioxide from the depleted water whereby the pH of the depleted water is increased.
A method of removing arsenic from water comprising:
- providing water containing arsenic from a source;
- contacting the water with carbon dioxide whereby the pH of the water is lowered to about 7 or less producing pre-treated water;
- and
- contacting the pre-treated water with an arsenic complex-adsorbing substance to produce arsenic depleted water.
An apparatus for removing arsenic from water containing arsenic comprising:
- a water flow from a source of water containing arsenic;
- a source of carbon dioxide in fluid communication with the water flow supplying carbon dioxide to the water flow to lower the pH of the water to about 7 or less producing a pre-treated water flow;
- and
- a contact chamber containing an arsenic complex-adsorbing substance in fluid communication with the pre-treated water flow to remove arsenic from the pre-treated water flow producing an arsenic depleted water flow.
A method of removing arsenic from water comprising:
- providing water containing arsenic from a source;
- contacting the water with carbon dioxide whereby the pH of the water is lowered producing pre-treated water;
- and
- contacting the pre-treated water with an arsenic complex-adsorbing coagulant to produce an arsenic depleted water.
A method of removing arsenic from water comprising:
- providing water containing arsenic from a source;
- contacting the water with carbon dioxide whereby the pH of the water is lowered producing pre-treated water;
- and
- contacting the pre-treated water with a metal based arsenic complex-adsorbing substance to produce arsenic depleted water.
An apparatus for removing arsenic from water containing the arsenic comprising:
- a water flow from a source of water containing arsenic;
- a source of carbon dioxide in fluid communication with the water flow supplying carbon dioxide to the water flow to lower the pH of the water producing a pre-treated water flow;
- and
- a mixing tank in fluid communication with the pre-treated water flow and a coagulant supply system supplying arsenic complex-adsorbing coagulant to the pre-treated water flow to remove arsenic from the pre-treated water flow producing an arsenic depleted water flow.
An apparatus for removing arsenic from water containing arsenic comprising:
- a water flow from a source of water containing arsenic;
- a source of carbon dioxide in fluid communication with the water flow supplying carbon dioxide to the water flow to lower the pH of the water producing a pre-treated water flow;
- and
- a contact chamber containing a metal based arsenic complex-adsorbing substance in fluid communication with the pre-treated water flow to remove arsenic from the pre-treated water flow producing an arsenic depleted water flow.
An apparatus for removing a metal or a metalloid from water containing the metal or metalloid comprising:
- a water flow from a source of water containing a metal or a metalloid;
- a source of carbon dioxide in fluid communication with the water flow supplying carbon dioxide to the water flow to lower the pH of the water producing a pre-treated water flow;
- a contact chamber containing a metal or metalloid complex-adsorbing substance in fluid communication with the pre-treated water flow to remove the metal or the metalloid from the pre-treated water flow producing a metal or metalloid depleted water flow;
- and
- a carbon dioxide stripping apparatus in fluid communication with the metal or metalloid depleted water flow for stripping the carbon dioxide from the depleted water.
Dependencies are inferred from the claim text.