LARGE-SCALE APPLICATION OF UF AND RO IN THE PRODUCTION OF DEMINERALIZED WATER

The water demineralization plant in Geleen (NL) for the production of boiler feed water from surface water with a maximum plant capacity of 1560 m(3)/h uses reverse osmosis (RO) as the basic process step for de salination. In order to ensure maximum operational reliability of the RO, a dead-end ultrafiltration (UF) pretreatment step is used, giving the best feed quality with respect to RO fouling behaviour. In order t o enable a proper design of the UF, a series of pilot-scale field expe riments were carried out on-site. The overall process design, the expe rimental results of those experiments and the resulting selection of a suitable UF membrane are described. The subsequent selection of a sui table RO membrane for the process is then largely determined by econom ic aspects, which may be deduced from the membrane properties, represe ntatively expressed in terms of salt passage and water flux (or requir ed feed pressure) of the respective membrane.