WATER & WASTEWATER ASIA July / August 2018 82 PWN TECHNOLOGIES (PWNT) has developed a new ion exchange process, known as SIX ® (Suspended Ion eXchange), that is an advanced solution to a worldwide challenge: To remove Dissolved Organic Carbon (DOC) from water to improve membrane f i l t rat i on performance. The suspended ion exchange process is also suitable for purifying unt reated sur face waters — removing sulphate, nitrate, and phosphate. It involves not just an ion exchange process, but also resin separation and dosing of regenerated resin. In addition, SIX includes techniques for reducing the level of salt regeneration. The process design is based on a fully validatedmodel and can be adapted to all commercially available resins. The philosophy of the SIX ® process is based on an advanced plug flow reactor followed by a specially designed lamella settler. Compared to other ion exchange processes for treating water containing suspended matter and organics, the single pass ion exchange process (SIX) distinguishes itself by compactness, a low resin concentration and inventory, low salt usage, high effluent quality and full control of the adsorption process without blinding the resin or producing biomass. The adsorption of the SIX process has been modelled to such a degree of accuracy that it is possible to design a reliable installation for any commercially available resin based on only a few jar tests. As the resins used have optimal adsorption capacities and rates, the overall performance is unsurpassed. To find out more about SIX ® , visit PWNT booth at L1-H28. Benefits of SIX ® • Unit is very compact with a small footprint • Model is fully validated • Reduced resin inventory • Full control • 100 per cent regeneration of dosed resin • No risk of resin blinding • Short resin contact times; no risk of biofouling • Low resin attrition; minimal resin loss • Can be used with all commercially available resins Additional advantages • No pumps are used to displace the resin, resulting in low attrition rates • New sensors are used to control resin concentration and water quality • Additional technologies have been developed to reduce salt usage About PWN Technologies PWN Technologies, a subsidiary of water supply company PWN in the Netherlands, was established to make the utility’s innovations in water treatment available to other water companies around the globe. The revenues of PWN Technologies are invested in R&D (research and development) programmes to strengthen PWN’s position as an innovative water supply company. PWN Technologies has developed advanced and sustainable solutions in water treatment, based on suspended ion exchange, ceramic membrane applications and advanced oxidation. PWN Technologies is located in the Netherlands (Velserbroek and Andijk) and Singapore.