Biodegradation of bisphenol compounds in the surface water of Taihu Lake and the effect of humic acids.

Bisphenol analogues (BPs) pollution in the aquatic environment is increasingly a worldwide concern. There is an urgent need to understand the fate of BPs in the aquatic environment. In this study, we studied the biodegradation of eight BPs in Taihu Lake and discussed the effect of humic acid (HA), which was extracted from Taihu Lake sediment, on the disappearance of BPs. Under aerobic conditions, bisphenol AF (BPAF) and bisphenol S (BPS) were recalcitrant to biodegradation in the lake water. The half-lives for bisphenol F (BPF), bisphenol A (BPA), bisphenol B (BPB), bisphenol E (BPE), bisphenol Z (BPZ), and bisphenol M (BPM) ranged from 34 to 75 days in the Taihu Lake water collected in October 2018 and 12-72 days in that collected in May 2019. The biodegradation of BPs in summer was significantly higher than that in autumn. The presence of HA promoted the disappearance of BPs from Taihu Lake water by adsorbing and binding BPs. The disappearance rate of BPs accelerated with increasing concentrations of HA. However, the presence of HA decreased the biodegradation of BPs. When the concentration of HA was 10 mg/L, the single-adsorption capacities for BPS, BPA, BPB, BPM and BPAF were 3.18-10.33 mg/g in the Taihu Lake water with little desorption. BP adsorption and desorption in the BP mixtures were different from that in the single BPs. Competitive desorption occurred among the mixtures. The results of this study are the first to indicate the biodegradation of eight BPs in natural lake water and the possible effect of HA on the fate of BPs in the environment.