Large-scale application of UF and RO in the production of demineralized water

Abstract

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 desalination. 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 to enable a proper design of the UF, a series of pilot-scale field experiments were carried out on-site. The overall process design, the experimental results of those experiments and the resulting selection of a suitable UF membrane are described. The subsequent selection of a suitable RO membrane for the process is then largely determined by economic aspects, which may be deduced from the membrane properties, representatively expressed in terms of salt passage and water flux (or required feed pressure) of the respective membrane.