Patent ID: 9670080
Date: 2017-06-06
CPC Classifications: C02F,E21B

Claim:
1. A method for reducing sulfide in oilfield waste water, the method comprising: contacting oilfield waste water with a combination of an oxidizer and an iron catalyst, the oilfield waste water comprising sulfide, the oxidizer comprising one or more of the following: a halogen oxidizer; a nitrate; a nitrite; a dichromate; or a nitrogen-chloro oxidizer; and the iron catalyst comprising an iron salt; the iron catalyst comprising one or more of the following: ferric sulfate; ferric chloride, or ferric nitrate; oxidizing the sulfide in the oilfield waste water to sulfate with the oxidizer in the presence of the iron catalyst to reduce the amount of the sulfide to less than 0.5 ppm, based on the weight of the oilfield waste water; and avoiding formation of elemental sulfur.