Mechanistic insights into phenolic compounds removal in constructed wetlands: efficiency comparison, synergistic...

Phenolic compounds (PCs), as persistent endocrine-disrupting chemicals, present a global environmental challenge. This review synthesizes the removal mechanisms of PCs in constructed wetlands (CWs), comparing the performance of different configurations. Results indicate that vertical flow CWs (VF-CWs) achieve superior removal of phenol (Ph) and bisphenol A (BPA) under aerobic conditions, primarily through the synergy of substrate adsorption and aerobic biodegradation, outperforming horizontal flow CWs (HF-CWs). Plant-microbe synergy is crucial, with vegetated systems enhancing the removal of BPA and nonylphenol (NP) via rhizosphere microbial enrichment and increased enzymatic activity. Hybrid CWs (Hy-CWs) with multi-stage units demonstrate higher removal efficiencies than single-stage systems, underscoring the advantages of integrated processes. Furthermore, the regulatory roles of key operational parameters, including substrate properties, temperature, and dissolved oxygen, are discussed. These insights provide a theoretical basis for optimizing CWs and outline future research priorities, including functional material development, multi-process technology coupling, and ecological safety assessment frameworks.