Comprehensive study on removal of bisphenol-S and its metabolic fate using aquatic macrophytes

Abstract

Bisphenol-S (BPS) is recognized as an emerging contaminant due to its potential estrogenic properties and is frequently detected in aquatic environment. The safety and environmental behavior of BPS is controversial. Furthermore, the removal studies of BPS from aqueous environment are scarce. In this study, we assessed the phytoremediation potential of three aquatic macrophytes (Iris pseudacorus, Ipomoea aquatica, and Typha angustifolia) for BPS removal from secondary wastewater effluent. BPS at environmentally relevant concentration (0.005 mg/L) was removed 100 %, 97 % and 97.5 % with I. pseudacorus, I. aquatica and T. angustifolia respectively. Twelve biotransformed products of BPS were identified through gas chromatography mass spectrophotometry. The enzymatic analysis showed induction of both phase I (laccase, 315 %; peroxidase, 739 %, superoxide dismutase, 881 %; aminopyrine N demethylase, 60 %) and phase II enzymes (glutathione S-transferase, 592 %) in the plant roots after 7 days of BPS exposure. A lab-scale vertical phytoreactor was constructed with PVC tubes that completely removed BPS in 14 days along with nutrients (phosphorus and nitrogen) and inorganic (heavy metals) contaminants from the secondary wastewater effluent. An analysis of the microbial diversity in the phytoreactor effluent showed an enhanced relative abundance of the phyla Bacteroidetes (20 %) and Proteobacteria (44 %) after BPS exposure. This study is the first report highlighting the removal of BPS by aquatic macrophyte and its fate in aquatic environments.