2. Plant construction

2.1 Basic principles

Plant size, number of columns, choice of resins, types and quantities of regenerants are mainly determined by :

• the required treated water flow rate ;

• the specified quality of treated water;

• the investment cost of the installation ;

• plant operating costs.

In the case of smaller installations, the focus is generally on reducing investment costs, even if regenerant consumption is somewhat higher. This is the case for laboratory demineralizers and domestic softeners.

As plant size increases, operating costs play an increasingly important role in the choice of...