As result of removal of impurities such H2S and Mercaptans in oil and gas, spent caustic is generated. Spent caustic is high toxic and contains several hazardous contaminants such as sulfides, Mercaptans, sodium salts and high COD level. Organics in spent caustic are very complex due to its source such as Phenols, Naphthenics and Cresylics.
COD level of these streams can be from 10,000 to 250,000 ppm Due to these contaminants in refinery spent caustic, these wastewaters are difficult to treat with conventional treatment system and need special design. Older practices such as discharging into water stream such the ocean or dilution is not sustainable. Naturalization with acid require massive amount of acid as 5-15% mass weight in spent caustic. There are various methods for caustic treatment each of which has their own advantages and disadvantages. There are several treatments for spent caustic such as Wet Air Oxidation (WAO), Advanced Oxidation Process (AOP) and Electrocoagulation (EC).
Watersafe Inc. with its partner established a turnkey containerized treatment package. This technology can remove up to 99% of COD and Sulfide compounds. Please contact us for more information.