The effect of ultrafiltration as pretreatment to reverse osmosis in wastewater reuse and seawater desalination applications

With an ever-growing world-wide demand for water and decreasing availabilit y, emerging technologies such as ultrafiltration (UF) hold the key to futur e water treatment. Two applications to use unconventional sources for water production are described. The reuse of effluent of wastewater treatment pl ants (WWTP) for high-quality water production will certainly be an interest ing application of UF in the years to come. The technical feasibility for t his application has been shown and operational costs have been estimated on the basis of three pilot plant trails. At 0.09 to 0.22/m(3), depending on the WWTP effluent quality, this may be considered to be economically attrac tive. Another application of UF is the pre-treatment of seawater reverse os mosis (SWRO) plants. These plants, of which a number are in operation in th e Middle East, are currently being operated at a fraction of their original design capacity due to poor performance of their conventional pretreatment . UF can provide a feed water quality, which provides SDI values well below 2, thus enabling the SWRO plant to perform at its original design capacity . Again, operational costs of this pretreatment are very attractive at 0.07 Euro to 0.09 Euro/m(3).