Demonstration of bioaugmentation in a fluidized-bed process treating 1-naphthylamine

The feasibility of using a fluidized-bed reactor with bioaugmentation to treat low-strength wastewater or slightly contaminated groundwater was evaluated. Tap water spiked with 1.6 to 12.6 mg/L of 1-naphthylamine was treated in a fluidized-bed reactor with a hydraulic retention time of 6.2 to 13.3 h. With conventional operation, the reactor was unable to maintain consistent removal because of cell washout. Continuous removal efficiency was greater than 90% using bioaugmentation through periodic addition of acclimated cells from an off-line enricher-reactor. The concept demonstrated by this research presents an alternative for biological treatment of wastes (dilute wastewaters and contaminated groundwater) which are not normally considered good candidates for biological treatment.