Performance comparison between activated sludge and fixed film processes for priority pollutant removals

This study compared the performance of activated sludge (AS) and fixed-film processes in removing organic priority pollutants from a municipal/industrial wastewater. The study employed parallel low- and high-loaded laboratory-scale AS and biological aerated filter (BAF) reactors. The research focused on the fate of six selected volatile organic compounds (VOCs), although GC/MS scans were also performed to evaluate the fate of other organic priority pollutants. The AS and BAF reactors achieved comparable VOC removals and stripping rates were slightly higher for the AS reactors; biodegradation rates were slightly higher for the BAF reactors. Observed removals, which ranged from 32% for methylene chloride to over 95% for toluene, compared well with removal rates observed in previous studies. Consequential absorption rates were observed for numerous basic or neutral and pesticide pollutants in both processes