Pharmaceuticals and Personal Care Products (PPCPs) constitute a group of compounds that are challenging to break down and potentially pose risks to both ecosystems and human health when they accumulate in water bodies. This study established and operated small-scale constructed wetland–microbial fuel cells (CW-MFCs) continuously for 60 days, maintaining a hydraulic retention time (HRT) of 3 days. The research aimed to assess the treatment efficiency of wastewater containing Ibuprofen (IBP) and Diclofenac (DCF) using different co-substrates (glucose, sucrose, and sodium acetate) and to analyze the impact of these co-substrates on the composition of bacterial communities within the CW-MFC. After 60 days of operation, CW-MFC achieved removal rates of 89.29% for IBP and 84.10% for DCF. The elimination of IBP was primarily dependent on co-metabolic degradation processes occurring in both the anode and cathode, while DCF removal relied on anodic co-metabolism. Additionally, various co-substrates have an influence on the bacterial community diversity of the anode and cathodes. The possible bacterial groups involved in PPCP degradation were identified. In summary, Glu was identified as a more suitable co-substrate for CW-MFC in the removal of IBP and DCF, while SA as a co-substrate favored the induction and enrichment of EAB in the anodes. These findings offer valuable insights into the potential of CW-MFC for mitigating emerging contaminants.

The effects of coastal embankments on nitrogen (N) cycling in the Spartina alterniflora salt marsh have been extensively reported. However, it remains unclear effects of the embankment on the sizes of diverse N subpools in the plant-soil subsystems year-round. This study examined seasonal changes in various N subpools of plant subsystems; soil subsystems [e.g., soil organic N (SON), recalcitrant organic N (RON), labile organic N (LON), dissolved organic N (DON), ammonium N(NH+4 N), and nitrate N(NO3-N)]; N mineralization [e.g., soil net ammonification (R_A) and nitrification (R_N) rate]; and immobilization [e.g., microbial biomass N (MBN)] in embanked and adjacent S. alterniflora natural salt marshes on the coast of Eastern China. The embankment significantly reduced the litter N storage by 62.7–71.8% over the four seasons and decreased the root N storage by 53.0% during winter. The SON, LON, RON, and N H +4 N concentrations declined significantly by 43.0–60.2%, 35.8–64.8%, 44.9–59.0%, and 20.8–42.2%, respectively, over the four seasons following the embankment construction. Furthermore, the embankment dramatically reduced the DON concentrations by 21.9% in spring, 14.6% in summer, and 10.4% in winter, while notably diminishing the NO3 N concentrations by 33.4% in autumn and 44.9% in winter, and the R_A and R_N in spring and summer. However, the embankment clearly increased the MBN concentrations during summer and autumn, the NO3 N concentrations in spring, and the R_A and R_N in winter at different levels. Due to the decreased soil N inputs from plants, the embankment decreased the organic and inorganic N subpools every season to varying degrees, except for the NO3 N concentration in spring. We suggest that the decreased soil salinity following embankment establishment might increase the uptake of ions by microbes, while stimulating the production of MBN. Ultimately, the NO3 N and DON were two vital N sources for S. alterniflora, and plants absorbed N from the soil to promote their biomass, as well as N concentration and storage. This study is conducive toward understanding the mechanisms behind the effects of coastal embankments on the N transfer among various N subpools in the plant and soil systems.