Is BPA only the tip of the iceberg? Occurrence and risk assessment of 32 bisphenol analogues in landfill leachate

While the environmental hazards of bisphenol A (BPA) are well-established, the occurrence and fate of emerging bisphenol analogues (BPs) in landfill leachate treatment systems remain poorly elucidated. Herein, we investigated the spatial distribution, removal efficiencies, and ecological risks of 32 BPs across 17 municipal solid waste landfills in China. Our results reveal the ubiquitous occurrence of BPs in raw leachate (5.10–3890 μg/L), with BPA and bisphenol C-dichloride (DCBPC) persisting as dominant congeners, and several of the highest concentrations being observed at eastern sites. Despite achieving > 94% aggregate removal, MBR-based processes demonstrated limited efficacy against recalcitrant congeners. Consequently, 2,4,6-TCP and DCBPC persisted in the effluent, dominating the residual profile (74.5% of the summed residual concentration). In contrast, advanced treatment processes proved highly effective, achieving near-complete elimination of these recalcitrant compounds. Furthermore, correlation analysis identified significant positive associations between total nitrogen/ammonia and BP concentrations (p < 0.01), suggesting that nitrogen-rich environments may facilitate BP persistence. Moreover, RQ analysis indicated that multiple treated effluents remained in the medium-to-high risk range, and the calculated estradiol equivalent quantities (EEQs) frequently exceeded thresholds for developmental toxicity in aquatic organisms. These findings underscore the inadequacy of conventional biological treatments for eliminating alternative BPs and highlight the critical need for advanced tertiary treatment to mitigate the shifting ecological risks posed by leachate discharge.