The effluent from the reed beds is pumped towards a pilot hall where different technologies – ultra filtration, ion exchange and reverse osmosis – are tested with the aim of upgrading it to production water for Dow. Both 350 m² Phytoair systems are equipped with various in-line sensors to monitor the systems.
“A chemical company like Dow needs a stable supply of high quality water. The wetland achieves this with a minimum of maintenance (once a year rinsing pipes and checking technical equipment) and low cost operation. After all, the staff of the wetland consists of the micro-organisms and reed plants, ”says Dion van Oirschot of Rietland.
The reed beds are monitored for two years by professor Diederik Rousseau of Ghent University with doctoral student Hafiz Khan. In several places of the Phytoair oxygen measurements are taken and in-line measurements continuously monitor the concentrations of ammonium, COD and nitrate. Sampling and analysis of influent and effluent on standard parameters and micropollutants are carried out by students of the Water Technology research group at Hogeschool Zeeland and specialized laboratories. The partners of this project are Dow benelux, Evides industry water, Scheldestromen Water Board, Ghent University, Hogeschool Zeeland and Rietland.