This thesis examines the economical viability of a full scale electrodialysis (ED) installation in a
wastewater treatment plant in Belgium. The goal of this ED treatment is to treat the RO concentrate
to create higher efficiencies in the whole treatment cycle so more clean water can be produced from
the same amount of wastewater. Also the removal of discharging RO concentrate water is considered
a goal of this ED installation. Currently the technical possibilities are checked with a pilot ED
installation but a full scale application should be evaluated on an economical basis.
The water for ED treatment has to be decarbonated to prevent scaling onto the ED membranes. To
do so, several treatments are possible. First an acidification treatment is examined to blow out the
scaling potential in the form of CO2 or to shift the scaling potential balance so no scaling can occur.
Another treatment with a pellet reactor adds basic chemicals to make the scaling molecules
precipitate onto pellets before scaling can occur in the ED membrane stack. All these treatments are
economically examined and compared. Also the CO2 production of these treatments are compared.
To evaluate the full scale project, the pilot installation is first examined to find all the economical
parameters that are necessary to economically evaluate the whole installation. With this calculation
in mind the full scale project is analyzed. It is found that the current wastewater treatment plant is
not capable of handling the extra flow of water created through the ED installation thus no real
benefits can be attained from the ED installation. Because of this constraint the ED installation is not
generating enough benefits to create a profitable system. Also the pilot installation is found to be
very expensive to treat the RO effluent.

Thesis submitted for the degree of Master of Industrial Management
Promotor:
Prof. Bart Van der Bruggen
Assessor:
Prof. Dirk Catrysse
Counsellor:
Yang Zhang
Academic year 2009 – 2010