“…Up to date, BAC systems have been adopted for treating various emerging contaminants in water and wastewater, especially hydrophobic contaminants with low molecular weights (Arnold et al, 2018; Chuang & Mitch, 2017; Cohen, 2001; Cuthbertson et al, 2020; Ibn Abdul Hamid et al, 2019; Li, Xu, et al, 2019). Many of the pesticides and pharmaceutical and personal care products (PPCPs), which have long been considered as emerging pollutants, can be effectively treated in fixed‐film wastewater treatment processes including BAC through both biodegradation and adsorption on the biofilm matrix (Chen, Pan, et al, 2019; Rattier et al, 2012; Reungoat et al, 2012; Sbardella et al, 2018; Tran et al, 2019; Zearley & Summers, 2012; Zhang, Gitungo, et al, 2017). On the other hand, unregulated and nitrogenous disinfection by‐products (N‐DBPs), microplastics and plasticizers, nanoparticles (NPs), and poly‐ and perfluorofluoroalkyl substances (PFASs) are the groups of recent contaminants of emerging concern in water treatment.…”