Wet air oxidation of spent caustic liquors

Shows how the wet air oxidation (WAO) unit at a petrochemical complex in Illinois solved the caustic disposal problem with a payback period of only one year. Explains that the unit treats a process wastewater, spent caustic, which is generated in a scrubber for acid gas removal from a hydrocarbon gas stream. Presents diagram of the WAO operation. Finds that although the equipment was not designed to operate at higher flow rates and lower COD concentrations, inventiveness and operating flexibility inherent to the system have allowed continued successful operation. Reveals that the cotreatment of plant biological sludge with the spent caustic liquor is being evaluated. Points out that if sludge oxidation is successful, 2 difficult waste treatment problems will have been solved in a single process.