2.2. System operation
The units were constructed in early summer of 2007, and were
planted immediately after their establishment, at a density of
14 plant stems/m2. They were initially filled with water and kept
flooded, in order to assist plant growth and adjustment to the bed
environment. The creation of the bacteria culture and of the biofilm
took place gradually through the natural process, without transferring
microorganisms from an activated sludge system. Starting in
October 2007, synthetic wastewater was introduced into the units,
which was designed to simulate to the best the characteristics of a
relatively strong municipal wastewater. It contained peptone (protein
source), cane sugar (source of saccharose,) and acetic acid as