The tank contained 673 m3 (178,000 gallons) of sour water. The initial H₂S readings from the vessel exceeded 50,000 ppm (5.0%) with ammonia readings of 560 ppm. The work plan included treating the tank water contents to remove the free ammonia typical of refinery sour water processes. FQE Ammonia Odor was pumped into the tank and circulated for 12 hours. Upon testing, the ammonia was non-detectable.

After the ammonia abatement was completed, an aqueous solution of FQE H₂S Scavenger was prepared and pumped into the tank. The contents were circulated for an additional 24 hours to ensure good contact was made between the vessel water and FQE H₂S Scavenger. The tank contents were sampled every two hours with the H₂S being reported at 0 ppm after 24 hours.

The chemical circulation was performed at ambient temperature and applied from bottom to top through a 3D nozzle mounted through the vessel’s top manway access. The spray nozzle was used to eliminate the high H₂S and ammonia concentrations present in the vessel’s head space. Upon completion, the treated water was processed through the wastewater treatment plant without delays.

This process was reported by plant personnel to have reduced their average outage time by at least 50%. The typical decontamination was completed by the slow addition of potassium permanganate liquid over a 5-8 day period, resulting in extra time and additional
disposal considerations being required.