oil refinery at night

Spent Caustic

Spent Caustic Treatment

In the refining industry sodium hydroxide is used to remove sulfur and other compounds from the oil. The “spent caustic” waste stream generated from this process contains high concentrations of hydrogen sulfide, phenols, and a variety of complex organic compounds. These compounds consume large amounts of oxygen and introduce varying degrees of inhibition or outright toxicity to the microorganisms in the refinery’s activated sludge wastewater treatment system (bioreactor). For wastewater systems that nitrify to meet effluent ammonia limits, nitrification can be reduced or stopped altogether in the presence of spent caustic. Often, the inherent inhibitory/toxic nature of the spent caustic waste stream requires expensive, offsite treatment by other vendors.

USP Technologies can chemically oxidize the spent caustic using hydrogen peroxide alone or in combination with an iron catalyst, to dramatically improve the “treatability” of this waste stream.

inside industrial plant

A spent caustic chemical oxidation program allows for more economical onsite treatment without harming or overloading the microorganisms. For reduced sulfur compounds, which exert a substantial oxygen demand in the bioreactor, hydrogen peroxide can be dosed to balance oxygen supply with oxygen demand, enhancing nitrification by assuring sufficient dissolved oxygen concentrations throughout the bioreactor. To improve the bioavailability of spent caustic, hydrogen peroxide can be combined with an iron catalyst to break complex organic compounds into smaller fractions that can then be utilized by the microorganisms.

USP Technologies

1375 Peachtree Street NE, Suite 300 N

Atlanta, GA 30309

Toll-free (877) 346-4262

Phone (404) 352-6070

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USP - Canada

3020 Gore Road

London, Ontario N5V 4T7

Toll-free (877) 346-4262

Phone (404) 352-6070

 View a Map

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