“…This takes place in the Schmutzdecke (dirt layer) that develops in the top soil as a result of successive deposition of organic waste, plankton and microbes, such as protozoa, bacteria, rotifers, bacteriaphages, and fungi; particularly, the bacterivores protozoa ciliate have large effect on decay (Ellis and Wood, 1985;Puigagut et al, 2007;Stott et al, 2003). The Schmutzdecke can improve in attenuation capacity with time (Schijven et al, 2013), and the effect of predation increases with higher temperatures (Ellis and Wood, 1985). Moreover, in subsurface-flow constructed wetlands the removal of E. coli can be enhanced in the presence of vegetation, since plants compete with bacteria for nutrients, and some plants produce secondary metabolites with antibacterial properties (García et al, 2010).…”