2. Material and methods
2.1. Description of the site
A pilot plant vertical flow constructed wetland for treating
real wastewater was designed, constructed and operated for duration of almost two years and still running. The pilot plant was
located within the vicinity of a wastewater treatment plant. The
treatment system included the following successive steps: coarse
screen, oil removal, primary settling tank then a wetland basin.
The total surface area of the basin was 457.56 m2
. The influent flow
rate was 20 m3
/day and the surface loading rate varied between
26.2 kg BOD ha
−1
day
−1
and 76.5 kg BOD ha
−1
day
−1
with a detention time of 7.7 days. The VFCW was fed with influent wastewater
using submersible pump and distributed through a net work of
PVC pipes. The water flow was measured by electromagnetic flow
meter. The flow rate and the run off of the pumps were controlled
using SCADA software. All the main climatic parameters affecting
the CW hydro-balance such as temperature, wind speed and direction, humidity and atmospheric pressure were also monitored on
daily basis and recorded with Solar Radiation Sensor. Fig. 1 shows
the design of the pilot scale VFCW