The application of constructed wetlands for the removal of human pathogens and conventional fecal indicators: A critical review

Abstract Reduction of human pathogens from wastewater is of great importance to human health. Constructed wetlands (CWs) are environment‐friendly systems that are capable of reducing chemical pollution as well as pathogens from wastewater. However, the insufficient knowledge on the removal of human pathogens and fecal indicator bacteria in CWs due to the complexity of removal mechanisms and influencing factors impedes an accurate understanding and optimization design of this eco‐sustainable technology, which is necessary for further improvement of CW performance. The pathogen removal process is complex and mainly influenced by hydraulic loading rate and retention time, macrophyte, seasonal variation, substrate and wetland type. The main removal mechanisms include sedimentation and filtration, predation and photoinactivation. Generally, subsurface flow CWs allow a better reduction of pathogens than free water surface flow CWs, whereas hybrid CW systems have the optimal removal performance. Finally, suggestions were provided for improving pathogen removal in CWs.