Key design factors affecting microbial community composition and pathogenic organism removal in horizontal subsurface flow constructed wetlands

Water shortages in arid and semi-arid areas such as the Mediterranean have prompted a need for wastewater treatment and subsequent reuse. Reclamation can be achieved through conventional intensive systems or natural, ecologically engineered treatments such as horizontal subsurface flow (HSSF) constructed wetlands. Depending on wastewater type, some pathogenic microorganisms may be present and, therefore, wastewater reclamation processes with disinfection could be required (Asano and Levine, 1998). Thus, research into sewage treatment is needed in order to reduce risks associated with improper sanitation, particularly in terms of wastewater reuse for crop irrigation.