Process for purification of aqueous solutions containing hydrogen sulfide, hydrogen cyanide, and ammonia
First Claim
1. A process for the purification of an aqueous solution containing hydrogen sulfide, hydrogen cyanide, and ammonia comprising adding an acidic compound to said aqueous solution in an amount sufficient to bring said aqueous solution to a first pH of not more than about 3.0 after formation of said aqueous solution, passing said solution through a first stripping column, contacting said solution with a first inert gaseous medium, thereby removing at least most of said sulfide and cyanide to form a partially stripped solution,adding an alkaline compound to said stripped solution sufficient to bring said stripped solution to a second pH of at least about 10.0, passing said stripped solution through a second stripping column, contacting said stripped solution with a second inert gaseous medium, thereby removing at least most of said ammonia to form a waste water solution.
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Abstract
Aqueous solutions which are contaminated by hydrogen sulfide, hydrogen cyanide, and ammonia are brought to a pH of about 3 or less after their formation and treated with an inert gas in a stripping column to remove the sulfide and cyanide. The pH of the solution is then increased to about 10 or more and the solution is again treated with an inert gas in a second stripping column to remove the ammonia.
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21 Claims
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1. A process for the purification of an aqueous solution containing hydrogen sulfide, hydrogen cyanide, and ammonia comprising adding an acidic compound to said aqueous solution in an amount sufficient to bring said aqueous solution to a first pH of not more than about 3.0 after formation of said aqueous solution, passing said solution through a first stripping column, contacting said solution with a first inert gaseous medium, thereby removing at least most of said sulfide and cyanide to form a partially stripped solution,
adding an alkaline compound to said stripped solution sufficient to bring said stripped solution to a second pH of at least about 10.0, passing said stripped solution through a second stripping column, contacting said stripped solution with a second inert gaseous medium, thereby removing at least most of said ammonia to form a waste water solution.
Specification