In the past 30 years or more, Nitto Denko have started to develop spiral-wound type reverse osmosis (RO) new thin composite membrane technology to apply to high quality water conversion process such as brackish water and seawater desalination.Recently Nitto Denko released the new products with LD Technology ? for difficult industrial applications and demanding municipal water and re-use RO applications.The advanced spiral-wound element with LD Technology ?, is based on a new idea of biofouling retardation-spacer-material and the improved structure. Therefore, in order to achieve low pressure drop performance of feed water channel, the RO element has an effective spacer of antibacterial property to control biofouling from the combination spacers. The LD products give us more advantages than Non-LD product in terms of biofouling mitigation. With the application of thicker spacer and further improvement in geometry from the normal 28 mil to a thicker 34 mil, lower differential pressures were maintained in long terms of operation. It suggests the advantage of LD technology in the aspects of energy saving and operation cost reduction in realplant application.On the other hand, the biostatic effect of feed-spacer significantly suppresses the growth of bacteria and deposition of EPS. It also contributes to the less foulant deposition on membrane and feed-spacer clogging by high fouling materials like bioslime and colloidal, thus resulting in more sustainable lower differential pressurein RO feed channel.LD Technology ? consists of improved the innovative thicker spacer geometry design and biostatic. The LD has the effect on initial lower differential pressure operation and cleaning performance with frequency and recovery than conventional products. These effects contribute the reduction of both Capex and Opex for RO plantoperations.