Field experience shows that multimedia filtration with microflocculation followed by an activated carbon filter unit is one of the most effective pre-treatment combinations to remove traces of suspended matter and to reduce the fouling index to the lowest possible level.
Raw water ultrafiltration instead of multimedia filtration is an alternative, with even better outlet qualities.
Activated carbon has shown a considerable efficiency with respect to TOC as well as oxidant reduction contained in the raw water. To a certain extent the AC filters reduce the TOC level of the reclaimed last rinses, too.
OSMOSTIL reverse osmosis is used successfully in water purification to remove the bulk of ions, bacteria, particles and TOC.
Depending on the raw water analysis the combination of demineralization by ion exchange processes and reverse osmosis may be the better choice.
Figure: Pretreatment and Make-Up with membrane-based processes
