“…Constructed wetlands (CWs) are artificial wetlands which are designed and constructed to manipulate the natural processes to treat wastewater, and can be classified into surface flow and subsurface flow wetlands (vertical or horizontal) according to their hydrology and flow path (Ji et al, 2002;Truu et al, 2009;Vymazal, 2010;Zhi and Ji, 2012). Compared to conventional wastewater treatment technologies, CWs have economical and eco-friendly advantages due to their low-cost, easy operation and low maintenance (Puigagut et al, 2008;Faulwetter et al, 2009).…”