Lanzarote IV, a new concept for two-pass SWRO at low O&M cost using the new high-flow FILMTEC SW30-380

Lanzarote, one of the Canary Islands, pioneer in Spain of seawater desalina tion systems with a considerable multiprocess desalination capacity, had ar rived to the point where some of the installations were obsolete, with syst ems that either due to their high energy consumption or simply because they were at the end of their life cycle, were only being use for water consump tion peaks due to the touristic seasons. As a consequence, a new RO plant w ith a 20,000 m(3)/d capacity was planned and tendered. This new plant had t o provide low salinity water (50 mg/l) at a recovery in the range of 50% an d this with the minimum energy consumption. This paper presents the winning concept for the plant which was constructed and started-up at the end of 1 999: Lanzarote IV. The plant uses the new FILMTEC (R)* high-capacity elemen t (non-HR) SW30-380 in the first pass and the low-energy membrane FILMTEC ( R) BW30LE-440 in the second pass. The paper presents the operating paramete rs and compares these with conventional SWRO plants.