Scaleup planned for a scale-reducing RO process

Rotec Ltd. (Ashkelon, Israel; http://www.rotec-water.com), a technology-transfer company of Ben-Gurion University of the Negev (BGN; Beer-Sheva, Israel), is developing a new desalination technology that promises to increase the water-recovery rate of reverse osmosis (RO) systems from 75–85% up to 95%. This can boost existing RO plant capacities by 5–12% while dramatically reducing the brine disposal volume, which results in savings of up to $0.09/m3 of product water, says CEO Noam Perlmuter. One of the main factors limiting water recovery in conventional RO systems is scaling caused by precipitation of sparingly soluble salts. This occurs because the salt concentration near the membrane surface can become 13–20% higher than the concentration of the bulk solution due to the permeation of water through the RO membrane. Rotec’s system prevents scaling from occurring by reversing the flow of feed before the salt concentration at the surface becomes saturated. The system incorporates two main technology components: a valve-controlling device, which enables the adaptation of Flow Reversal to Tapered-Flow RO, and a Saturation and Deposition Sensor, which combines a detection array and a control algorithm that triggers…