On June 24, Biotreatment Area systems were turned over from systemization to operations, nearly completing the systemization phase at the Pueblo Chemical Agent-Destruction Pilot Plant (PCAPP).

“We achieved a milestone last month when Immobilized Cell Bioreactor (ICB) modules 3 and 4 and corresponding Bioreactor Off-gas Treatment System were turned over,” said Dr. Yakup Nurdogan, cognizant system engineer, PCAPP. “This is significant because we are now ready for pilot testing.”

The purpose of the biotreatment system is to treat hydrolysate and recover, recycle and reuse water at the plant, where there is a limited water supply from groundwater, said Dr. Nurdogan.

During agent destruction operations, hydrolysate, a byproduct of the chemical agent neutralization process, will be pumped into the ICBs to be treated by an aerobic biological treatment process oxidizing organics by biomass, or microorganisms, said Dr. Jim Earley, chief scientist, PCAPP.

During surrogate testing, which began in early June, ICBs were tested with thiodiglycol (TDG), the primary component of hydrolysate, manufactured by BASF of Ludwigshafen, Germany. Five batches of increased concentrations of TDG were added to the ICBs, seeded with biomass, over a five-day period. Preliminary results show greater than 99 percent TDG removal efficiencies during batch and initial continuous flow operations, said Dr. Nurdogan.

With all PCAPP systems and facilities turned over to operations, pilot testing, the phase when chemical agent-filled munitions will be gradually introduced, will begin once systemization has been certified as complete and all other approvals and permits are in place.