Bioaugmentation & Baseloading: Alternatives for Biodegradation of Acrylonitrile to Low Levels in Publicly Owned Treatment Facilities

Spartanburg Sanitary Sewer District (SSSD) evaluated options for treatment of industrial wastewater containing acrylonitrile at the Lower North Tyger River Reclaimed Water Treatment Facility.Bioaugmentation and Baseloading were two methods studied in bench-scale tests to achieve effluent acrylonitrile concentrations of 0.9 μg/L, which translates to a 4-log removal based on the projected influent concentration. For bioaugmentation, two activated sludge treatment trains were studied, a control and a test. The results indicated that the test reactor which received the bioaugmenting microbes could degrade acrylonitrile to produce effluent with acrylonitrile concentrations lower than 0.3 μg/L.Baseloading was studied using four activated sludge treatment trains by the continuous addition of acrylonitrile into two out of the four reactors in order to grow and maintain microbes capable of degrading acrylonitrile. Results from this testing indicate that the baseloaded reactors could reduce the concentration of acrylonitrile from 6,000 μg/L to less than 1 μg/L after acclimation.