Isolation and application of an ibuprofen-degrading bacterium to a biological aerated filter for the treatment of micro-polluted water

Ibuprofen (IBU) is widely used in the world as anti-inflammatory drug, which posed health risk to the environment. A bacterium capable of degrading IBU was isolated from activated sludge in a sewage treatment plant. According to its morphological, physiologic, and biochemical characteristics, as well as 16S rRNA sequence analysis, the strain was identified as Serratia marcescens BL1 (BL1). Degradation of IBU required the presence of primary substrate. After a five-day cultivation with yeast powder at 30°C and pH 7, the highest degradation (93.47%±2.37%) was achieved. The process of BL1 degrading IBU followed first-order reaction kinetics. The BL1 strain was applied to a small biological aerated filter (BAF) device to form a biofilm with activated sludge. IBU removal by the BAF was consistent with the results of static tests. The removal of IBU was 32.01% to 44.04% higher than for a BAF without BL1. The indigenous bacterial community was able to effectively remove CODMn (permanganate index) and ammonia nitrogen in the presence of BL1.