In August of 2006 the wastewater treatment plant (WWTP) for the Frontier Oil Refinery in Cheyenne, Wyoming received a new effluent discharge limit that required greater ammonia removal than the plant had historically been able to maintain.
The existing WWTP had been unable to sustain MLSS concentrations high enough to maintain the required SRT in the bioreactors. A combined suspended growth and attached growth nitrification process was determined to be the most cost-effective technology for upgrading the existing bioreactors at Frontier’s Cheyenne Refinery. Frontier examined a number of IFAS suppliers and selected BioPortz carrier media. In June of 2007, during a regularly scheduled refinery turnaround, the bioreactors were retrofitted with effluent screens and BioPortz media was added to their North plant bioreactor. By mid-August the reactor contained 93 m3 (approximately 54,000 square meters) of media and the effects of the additional fixed biomass were already being seen in the plant performance.
The success of the North plant with BioPortz IFAS led to the decision to convert the South plant to IFAS as well. Both facilities have been successfully meeting their nitrification limit of 2.1 mg/l subsequent to conversion to the Entex BioPortz system.
The success of these two BioPortz installations was highlighted in an article in the August/September 2009 issue of Industrial Wastewater magazine (Vol. 8, No. 4).
17,050 ft3 of BioPortz moving media, providing over 10 MM ft2 of biologically active surface area
Consistent complete nitrification despite numerous process upsets
Relevant Papers & Articles: