Water. desalination + reuse

TECHNOLOGY provide over resin-based water softeners is the elimination of the need for salt for recharging. CDI-based water softeners can be viable in many US states, such as California, which have strict brine-disposal regulations associated with operation of resin-based water softeners. CDI is also attractive for many other low TDS applications such as treating input water for cooling towers, point-ofentry related water treatment, and treating produced water from oil, gas and mining. CDI, which once promised to offer lowcost seawater desalination in the 1990s, is yet to be fully commercialized, though the technology has matured over the past several years. The applications where CDI can be beneficial at an early stage of technological maturity are becoming well-defined, which is a positive sign for the low relative investment it has received. Most CDI companies are becoming realistic about its potential and the challenges being seen. There is, however, a large gap in the understanding of the challenges and opportunities between the academic researchers and CDI manufacturers It is unclear what market will become the major initial market for CDI. Groundwater decontamination in the developing world is a large market with unmet needs and, if CDI succeeds, it may very well represent the major market for the technology. However, resin-based water-softener replacement or water treatment for cooling towers may also be attractive applications. We envision large investments in CDI technology, and many startups will enter and succeed as the market becomes better defined and very specific niches become clearer. Despite the challenges, it is very possible that CDI will play a significant role in the water industry, while its short-term impact may be much less than what was once hoped. l ACkNOwLEdGmENTs The authors would like to thank Bart vanLimpt (Voltea – Netherlands), Mariella Servida (Idropan – Italy), Narender Ahuja (HEW Water - India), and Stephen Jaffe (Material Methods, LLC – USA), for helpful discussions about CDI. CDI, and developed electrode-making processes and prototype deionization units. Since 2011, he has been working on developing specialty batteries at FlexEl, LLC. He can be reached at Lawrence.E.Weinstein@GMail.com. Ranjan Dash is a techno-commercial professional with over 10 years of experience in the development and management of materials science related technologies. Most recently, he served as CEO of Y-Carbon Inc, a Drexel University spinoff involved in development and manufacturing of electrodes for CDI. Ranjan has a PhD in Materials Science and Engineering, and an MBA in Organization Management from Drexel University, and BE (BS equivalent) in Ceramics Engineering from National Institute of Technology, Rourkela (India). Ranjan is Principal at Dash and Associates, LLC. He can be reached at RanjanKumarDash@GMail.com. WE UNDERSTAND DESALINATION & REUSE TECHNOLOGIES At Severn Trent Services we offer innovative treatment solutions to meet a variety of desalination and water reuse needs. – TETRA® DeepBed™ tertiary filters are an economical solution for the removal of TSS <2 NTU or <5 mg/l TSS and < 0.2 mg/L phosphorus. TETRA Filters account for >10% of the world's water reuse capacity. – TETRA® LP Block™ lateral underdrains are ideal for pretreatment filtration at desalination plants. The GroutGrip™ and the new Anchor-Rite® designs offer low installation costs and even air/water distribution, delivering reduced operating costs over other underdrains. – UAT™ desalination systems are suitable for treating a wide range of salinity application up to 10+ MGD (1,500+ m3/hr). UAT EDI systems are offered to polish RO permeate. For more information on desalination and water reuse solutions e-mail stwpi@emirates.net.ae or visit www.severntrentservices.com AbOuT THE AuTHOrs Lawrence Weinstein is an electrochemical and materials science professional. He earned his MS in Materials Science & Engineering from Rutgers University in 2008. From 2008 to 2011, he worked on supercapacitor carbons, carbon electrodes and CDI at Y-Carbon Inc. He contributed to several technical proposals on November-December 2013 | Desalination & Water Reuse | 37 |

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