The Llobregat DWTP can process up to 3 m3
/s with the conventional treatment including [11,12]: pre-oxidation with potassium
permanganate, coagulation, flocculation, oxidation with chlorine
dioxide, sand filtration, granular activated carbon filtration (GAC),
and final chlorination using NaClO (Fig. 1). After GAC, it is possible to process up to 2.3 m3
/s by means of an EDR brackish water
desalination plant, with the aim of reducing bromide and also
salinity (approximately 75% reduction of electric conductivity) to
controltrihalomethanes (THMs) formation in the distribution system. The EDR process includes nine modules with two hydraulic
EDR stages with a total of 576 stacks of 600 cell pairs in each stack.
The EDR effluent is remineralized and disinfected by using NaClO
and can be distributed directly to the network or optionally mixed
with the water produced in the conventional units.