A confidential client that manufactures fire-fighting equipment and chemicals operated a test facility to evaluate the effectiveness of their products, and discharged the resulting wastewater to a sanitary sewer. The sewer authority limited the volume of the manufacturer’s discharge due to the foaming properties of the wastewater, which limited the test activities that could be conducted. The manufacturer needed a method to pretreat the wastewater to significantly reduce foaming prior to discharge.

AECOM identified potential treatment technologies and coordinated bench and pilot studies for pretreatment of the manufacturer’s wastewater, with the objective to remove foaming materials, including PFAS, from the wastewater prior to discharge to the municipal sewer system. Technologies evaluated through bench-scale treatability testing included air-sparged hydrocyclone, electrocoagulation, membranes (ultrafiltration, nanofiltration and reverse osmosis), anaerobic biological treatment and evaporation. Upflow anaerobic sludge blanket biological treatment and evaporation technologies were further evaluated through on-site pilot testing. Anaerobic biological treatment, membranes, and evaporation technologies proved effective to varying degrees in reducing the foaming properties of the wastewater, and in removing specific chemicals, including PFAS, which contribute to foaming.