Toxicity of bisphenol A to aerobic granular sludge in sequencing batch reactors

In this paper, the toxicity of bisphenol A (BPA) on the performance of aerobic granular sludge was investigated in lab-scale SBRs. The result showed that exposure of BPA had an inhibition on the activities of heterotrophic bacteria and nitrifying bacteria during typical cycles. Polysaccharide (PS) and protein (PN) contents in loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) were significantly changed with the addition of BPA. Meanwhile, three-dimensional excitation–emission matrix (3D-EEM) spectroscopy and Fourier transform infrared spectroscopy (FTIR) technologies were used to characterize the chemical components of EPS in the presence of BPA. 3D-EEM indicated that the exposure of toxic BPA had a significant impact on the changes of fluorescence peak locations and intensities of LB-EPS and TB-EPS. FTIR results implied that similar functional groups were observed but with small changes, including amino group, hydroxyl group and carboxyl group.