Treatment of gas well hydrofracture wastewaters
AssigneeProChemTech International, Inc.
InventorTimothy Edward Keister
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Abstract
A method of treating a wastewater is provided and can be used, for example, to treat a gas well hydrofracture wastewater. The method can involve precipitating barium as barium sulfate, precipitating calcium and strontium as calcium carbonate and strontium carbonate, precipitating magnesium hydroxide, and filtering out the metal compounds to form a recycle water. The recycle water produced from the method is also provided, as is a method for using the recycle water as a gas well hydrofracture water. In some embodiments, discharge water from a coal mine, and/or water from an abandoned coal mine, is used as a source of sulfate ions to precipitate barium as barium sulfate.
Claims17
A method comprising:
- contacting a metal-containing wastewater comprising barium with a source of sulfate ions under acidic oxidizing conditions:
- precipitating at least 90% of the barium from the metal-containing wastewater, in the form of barium sulfate;
- flocculating and removing the barium sulfate from the stream of metal-containing wastewater, to form barium sludge and a first treated wastewater, wherein the barium sludge is non-hazardous according to the USEPA TCLP leachate test;
- contacting the first treated wastewater with a source of carbonate ions;
- precipitating one or more metal carbonates from the first treated wastewater after contact with the source of carbonate ions, to form a mixture of second treated wastewater and one or more metal carbonates;
- contacting the mixture with a source of hydroxide ions;
- and
- precipitating one or more metal hydroxides from the second treated wastewater.
Dependencies are inferred from the claim text.