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Turn on the faucet and it is likely that clean, drinkable water will come out; water that can be safely consumed. However, one in four cities around the world are water-stressed, and almost 97 percent of the Earth’s water is undrinkable. From the water crisis in Flint, Michigan, to droughts across the country, the significance of water utility and sustainability is more prevalent than ever before. To address the future of the water utilities, academics, entrepreneurs, business leaders, and thought leaders came together to discuss the future of water in the United States and around the world at the fifth annual MIT Water Summit on Nov. 17 and 18, hosted by the MIT Water Club. Members of the MIT Water Club moderated five panels over the two-day summit. This year’s topics ranged from the role of policy and economics on the future of water to the influence of industry and academic advances, but the overall vision was toward the future. “My aim was to hold an event with a broad enough appeal, but a specific focus explored through different approaches, such as technology, finance and policy,” said Gualtiero Jaeger, director of the MIT Water Summit and PhD candidate in the MIT- Woods Hole Oceanographic Institution (WHOI) Joint Program. “The theme ‘water utilities of the future’ gradually developed out of our initial ideas, and we looked for speakers with relevant expertise. Here our alumni and other connections helped us immensely.” “Creativity is part of the daily DNA of the water industry,” said keynote speaker George Hawkins, CEO and general manager of DC Water. Hawkins noted that many solutions to water problems require thinking outside the box, and cited the modernization and re-branding of DC Water to increase public awareness of their water utility. Similar creativity emerged through the interdisciplinary discussions at the MIT Water Summit. Luis Montestruque, president and CEO of EmNet, suggested the possible overlaps between green energy and water systems. Noting the use of solar energy to power electronic street signs, he questioned whether water utilities could follow to lower the energy costs. Stephen Estes-Smargiassi '79, director of planning and sustainability at Massachusetts Water Resources Authority (MWRA) and an alumnus of the MIT Department of Civil and Environmental Engineering (CEE), served as a keynote speaker and gave the Massachusetts perspective of water and energy. In his talk, Estes-Smargiassi highlighted the significance of water as an energy source, pointing out that 31 percent of the energy needed by MWRA is renewable energy, meaning the amount of money spent purchasing energy and power has decreased. By recycling water, Massachusetts is simultaneously creating energy. Ed McCormick, president of McCormick Strategic Water Management, cited potable reuse as one major example of creativity in the water sector during the panel on the role of economics. Potable reuse is the use of technologies to treat wastewater without putting water back into the environment and through the water cycle. McCormick acknowledged the negative perceptions people have of associating human waste with drinking water. “We replicate the water cycle with technology; we can do as good a job as nature. Those negative perceptions are changing and that’s where I see the creativity coming big time. It hasn’t quite swept to areas where you have more water than you need, but it’s certainly happening in the Southwest,” he said. Professor Gabriella Carolini of the MIT Department of Urban Studies and Planning suggested that there is no shortage of technological innovation, but that technological implementation is the major issue in the water sector. “Implementation is a problem that is not just financial, regulatory, technological or social; it’s a combination of all of those things, so we need to look at the implementation issue,” she said. Current policies and regulations are also not always conducive to rapid execution of news ideas. One component to this issue is the extensive pilot period, when technologies and ideas are studied before used widely. “We pilot for so long that by the time you actually determine that something is effective, there’s a new technology that we want to pilot. What we want to do is release some of the regulations a little bit so that we can promote some of these innovative technologies that are out there” said Mary Barry, executive director of New England Water Environment Association (NEWEA). Instead of hindering creative ideas with regulations and pilot programs, “We should be promoting innovation. That’s the only way we are going to grow and the only way we’re going to make things more efficient, both on the energy side and on the financial side,” she said. The creation of innovative technologies and their aligning with regulatory standards are only worth so much until the general public is on board with their implementation. As Ed McCormick suggested, changing the public’s perception of an issue of new innovative solutions is critical to the success of the product and the water sector. Communicating with the public to implement new ideas and technologies Speakers noted that reaching the general public is a difficult task, especially with the wide variety of media outlets and fragmented audiences. “I think the media can be a great asset to us as an industry, I just don’t think water is their focus,” said Mary Barry of NEWEA. One way to reach adults is through their children, who often talk about what they learn with their parents at home, she highlighted, citing the effectiveness of marketing to children. “Talking to students in schools allows them to go home and talk with their parents about something their parents might not be thinking about, because it has always been a luxury for them to have clean water and sanitation,” Barry said. The media is still considered a valuable method, however: “The full spectrum of media is an extremely useful tool, for even controlling outstanding systems like our own. I would say that the situation in Flint is an experience that is super important. It’s one thing to say that we have achieved amazing results in drinking water in this country, but I might suggest that we are only as good as our weakest link, and if something like that can happen in Flint, then it can happen anyplace,” said Carolini. Communication takes many forms beyond the media as well, such as through access to data. The availability and transparency of data in the water sector was a theme that continued throughout the Water Summit. During the panel “Visions for the Future,” panelists discussed the presence of smart systems, and the observation of resulting consumer behavior changes. Professor James Wescoat of the Department of Architecture and the MIT Tata Center spoke of staying in a hotel in Europe that displayed water meters in each room and showed how much water was used when a visitor turned on the shower or the sink. He recalled hearing fellow travelers discuss how few liters of water they used, each wanting to be lower than his counterpart. On that note, George Hawkins pointed out that when DC Water installed automatic meter readings in 2002, they noticed drops in water use. DC Water noted similar decreases when they began sending high-use notification alerts to customers, courtesy messages notifying customers of significant changes in water use, which could indicate leaking pipes. Alexander Heil, chief economist of the Port Authority of New York and New Jersey, made a similar point about water usage during the panel on the role of economics, noting that without smart systems and up-to-date information of one’s water usage, there is a disconnect between how people pay for water and how they use it. “There is a discrepancy between the point of usage and the point of payment. For example, if you have a quarterly billing cycle, nobody remembers how they used water three months ago.” The availability of data at water utility plants is crucial for the plants to troubleshoot any issues with their product. Anupam Bhargava, vice president of advanced technology and innovation at Xylem Inc., discussed this importance through disruptive sensing capabilities, one of the areas Xylam is looking into for the future. Disruptive sensing capabilities would allow water utility plants to detect issues immediately and allow them to be proactive in finding a solution. Noting that water, unlike other products commonly sold, cannot be recalled once it leaves the plant, Bhargava said that “real-time sensing capability is going to allow our customers to operate and manage their plants a lot more productively and safely.” Disruptive sensing capabilities would thus allow water utility plants to have important information at their fingertips and to avoid major public health hazards. Collaborating to solve major issues in the water sector Collaboration is often seen in the water sector to address major issues and find solutions. However, collaboration does not always mean centralized ownership. George Hawkins of DC Water mentioned the challenges of creating a centralized water system, because smaller municipalities prefer to maintain ownership of localized water sources. Instead, he proposed the creation of a more coordinated system on a broader scale, rather than centralized ownership. Ed McCormick shared that he has started to see such coordination through regional partnerships between smaller utilities. “In the San Francisco Bay Area, there are nearly 60 utilities that all discharge in the San Francisco Bay, some of them are very small and others are very large. What we have seen are agreements where small utilities can connect with other utilities to purchase bulk chemicals and get the benefit of scale, that larger utilities can get,” McCormick said. Marcus Gay, executive director of New England Water Innovation Network, pointed out that “innovation isn’t just about new technological solutions, it’s about bringing both innovative technological solutions and market adoption together. It’s an entire process.” One way to do this is to foster collaboration between academia and the water industry markets, to create a well-researched product or plan to implement and have a real-world impact. This was brought to life by the Water Summit’s panel on “Academia to Markets.” John Lienhard V, professor in the MIT Department of Mechanical Engineering and director of the Abdul Latif Jameel World Water and Food Security Lab, noted that the best partnerships are with people who understand the need for water. “We have worked with a number of international institutions from countries that have serious water challenges. We have tried to get into these issues with them because they understand that these are not simply academic problems, but they are problems that can be translated back into the needs of their countries and societies in a way that provides water to people’s taps, that help people actually live and survive. In those cases, we have seen that the research is productive, it is viewed as important, it is supported well and it has the impact we need in both the practical and academic side,” he said. The fifth annual Water Summit was a full house, complete with academics from MIT and neighboring schools, business leaders, thought leaders, and students. Sami Harper, a graduate student in CEE, attended the summit to find out more about how changing technology is affecting the way we get our water. “I learned a lot from the keynote addresses which shed some light on water utility operations and the future of the industry,” she said. Members of the MIT Water Club also benefited from the event. “The interactions with professionals beyond our academic research was immensely valuable. We received insight into the water industry and the workings of institutions and companies in the water world,” Gualtiero Jaeger said. Sponsors for this year's Water Summit included Desalitech, Gradient Corporation, Abdul Latif Jameel World Water and Food Security Lab, the MIT Department of Civil and Environmental Engineering, Massachusetts Clean Energy Center, New England Water Innovation Network, Pepsico, Woods Hole Oceanographic Institution, and Xylem.

News Article | August 22, 2016

MIT faculty, staff, and students gathered at the Wong Auditorium, accompanied by many representatives of member companies of the MIT Industrial Liaison Program (ILP) and other attendees from the corporate and nonprofit sectors, for the Abdul Latif Jameel World Water and Food Security’s first major event, on April 27 and 28. Co-sponsored by ILP and organized around a theme of innovation and collaboration, the conference highlighted the growing need for creative, cross-sector problem-solving to address significant food and water security issues around the world. As the challenges involved in providing safe and sufficient supplies of food and water to an ever-growing and increasingly urban world population multiply, multisector partnerships and collaborations are becoming increasingly important for addressing system-level issues, as well as promoting the development and adoption of new technologies. Following opening remarks by Abdul Latif Jameel World Water and Food Security (J-WAFS) director John Lienhard, who introduced J-WAFS as MIT’s Institute-wide initiative to coordinate and lead research related to water and food, keynote speaker Ralph Jerome, vice president for innovation for Mars, Inc., noted the significant role that the agriculture sector plays in climate change and how “uncommon collaborations” can help address the system-level challenges we face. “Food and agriculture are not only a major contributor to climate change but probably also one of the areas that will be most hit by it,” he noted. “While innovation is important to sustain a business, it’s also crucial in a world facing the grand challenges of feeding a growing population, apportioning ample fresh water to all, bringing degraded lands back to production, decreasing food waste, and creating civilization that's resilient to climate change.” J-WAFS organized the day-and-a-half program, which highlighted innovative water, food, and agriculture technologies under development at MIT, including current research by MIT faculty as well as numerous startups with MIT affiliations. Professor Christopher Voigt of the Department of Biological Engineering, for instance, presented his J-WAFS-funded research on transferring the nitrogen-fixing capabilities of legumes to cereal grain crops. Currently, grain crops — particularly rice, wheat, and corn — require the addition of nitrogen to the soil, resulting in environmental impacts in places like North America, where over-fertilization can lead to problems such as algal blooms, as well as dramatically lower crop yields in places like Africa, where chemical fertilizer is beyond the economic reach of many farmers. Noting that this challenge was identified as far back as the late 1970s as “one of the two biggest problems for genetic engineering to solve,” he described recent advances in his lab that have addressed some of the most significant technical hurdles. Karen Gleason, associate provost and the Alexander and I. Michael Kasser Professor in the Department of Chemical Engineering, addressed the challenge of food- and water-borne pathogens, noting that the World Health Organization estimates that one in 10 people worldwide fall ill every year from eating contaminated food, and 420,000 deaths are attributed to these pathogens. Using chemiresistor technology that her lab has developed for a variety of applications, she is developing biosensors that can detect pathogens in food in real-time using quick and easy sample preparation. With a very low detection limit, this technology would represent a significant improvement over conventional methods. Two other keynote speakers addressed the need to connect appropriate technologies to markets. “How do you connect the technology to the market in order to get the innovation to the end user?” asked Kavita Prakash-Mani, who is leading Grow Asia, a new initiative of the World Economic Forum. She described the agriculture sector as the “largest economic driver globally, with the largest environmental impact from any sector, and also the biggest social impact given the number of people working in it.” Yet the majority of the world’s 550 million farmers are smallholder farmers, and many of them are chronically hungry themselves. Noting that farmers can be very averse to change, she emphasized the need to work collaboratively with them to design and implement new technologies. In addition to innovation and technology development, the conference also featured a panel addressing “Risk and Resilience in an Era of Globalization and Climate Change.” Moderated by Steve Polski, senior director and general manager for Cargill’s Responsible Supply Chains Joint Advisory Business, the panel featured professors and researchers from MIT who address various threats to the world’s agriculture and food supply chains. Colette Heald, the Mitsui Career Development Associate Professor in the Department of Civil and Environmental Engineering, who also holds an appointment in the Department of Earth, Atmospheric and Planetary Sciences, talked about the impact of both air pollution and climate change on future crop yields, and stressed the need for better environmental monitoring to understand the risks. Retsef Levi, a professor in the MIT Sloan School of Management, addressed food safety as a supply chain issue, and Alexis Bateman, director of MIT’s Responsible Supply Chain Lab, emphasized the importance of bringing more transparency and honesty to international supply chains in order to help companies control risk related to supply, reputation, and environmental impact. Addressing a question to the panel about how education and research can help reduce corporate and social risk, Levi stressed the role of MIT’s industry connections in taking research to the field, and all panelists agreed about the importance of interdisciplinary research and the need to pursue research related to real-world issues. The conference also featured a keynote by Tim Prewitt, executive director of International Development Enterprises (iDE). Kicking off a panel on agricultural technologies, he noted that the extremes in crop productivity across the world suggest huge opportunities to grow more food with improvements in technology and farming methods — particularly in places like Sub-Saharan Africa, where soils are depleted, there is only rain-fed irrigation, and crop yields are lowest. Addressing the need for innovation in business markets as well as technology, he noted that the “single biggest consideration is how to get products to market quickly and cheaply.” That is also the interest of the many startup companies that participated in the conference’s startup showcase. Conference attendees had the opportunity to talk with representatives of nearly two dozen companies. Some, such as the young agricultural drone company Raptor Maps, were only recently started by MIT students, and others, such as Desalitech, a company offering large-scale water purification and desalination technology, already have substantial capitalization and business volume. Desalitech is currently licensing several patents pertaining to desalination, low-energy deslination, and membrane technology from MIT. Commenting on J-WAFS’ role at MIT, director John Lienhard described one of its programs, J-WAFS Solutions, which supports the commercialization of MIT technologies and provides support and mentorship for MIT faculty and students around food and water innovation and entrepreneurship. “We heard over and over at the conference about the importance of not just innovating, but building successful companies, enterprises, and collaborations that enable those innovations to make a difference in the world,” he said. “The success of this conference signals the growing interest the MIT community has in applying MIT’s excellent track record in this regard to our food and water security challenges.”

News Article | September 16, 2016

Who wants to drink that dirty water? Some of New England's leading breweries will compete Oct. 1 to see who can turn the questionable water of Boston's Charles River into the tastiest suds. Six area breweries have signed on for the first ever "Brew the Charles" challenge, a highlight of HUBweek, a weeklong Boston-area festival celebrating innovation in art, science and technology. Nadav Efraty, CEO of Desalitech, a Massachusetts water treatment company that's sponsoring the competition, hopes it helps spotlight the importance of water conservation and water-saving technologies. "We're having fun here, but at the end of the day, we want to educate the public and decisionmakers," he said. "We're all efficient with our energy because we know it has environmental and financial costs. We need to think exactly the same way about water." The river, which winds through 23 Massachusetts communities before ending in Boston Harbor, has come a long way since it gained notoriety in "Dirty Water," the Standells' 1960s hit and one of Boston's adopted theme songs. Upgrades to wastewater treatment plants over the decades since, now prevent raw sewage from being dumped directly into the river, and environmental regulators have cracked down on improper sewer connections. The U.S. Environmental Protection Agency gave the Charles a B+ for meeting water quality standards for almost all boating and some swimming in its most recent annual report card. There's even a movement to build a permanent swimming facility in the river. A portion of the proceeds from "Brew the Charles" will go toward that effort. Desalitech pulled about 4,000 gallons of water from the river and treated it in one of its reverse osmosis systems. The water arrived last month at Boston Beer Co. (the makers of Samuel Adams), Cape Ann Brewing Co., Castle Island Brewing Co., Harpoon Brewery, Idle Hands Craft Ales and Ipswich Ale Brewery. Jennifer Glanville, the brewer at Sam Adams, said it is brewing a German "helles" lager that she believes will "showcase" the water's unique character. They're calling it "80 Miles of Helles," after the 80-mile length of the Charles River. Adam Romanow, founder of Castle Island Brewing, said his team went with a dry hopped cream ale in hopes that it will also "let the water shine through." The Norwood, Massachusetts brewery is calling their concoction "Chuck." "With this style, there's not much to hide behind," Romanow explained. "It's a traditionally lighter, lower-alcohol, classic American style that has been around for eons but generally gets a bad rep despite being absolutely amazing - kind of like the Charles itself." Alexandra Ash, a spokeswoman for the Charles River Watershed Association, which has worked for decades to improve the river's health, applauded the spirit of the competition but cautioned that it's still not always safe to swim in the Charles, let alone drink from it untreated. The association this month found high levels of cyanobacteria, a blue-green algae that can irritate the ears, nose and throat and sicken those who drink or swim in it. "We still have a bit more work to do until that's a possibility," Ash said of drinking river water. "But what's cool about this competition is that it shows off another great aspect of greater Boston — our local water innovation and expertise." Brewers at Sam Adams and Castle Island Brewing report the Desalitech-treated water was high quality. They used it as they would have any other water source — no additional steps or special treatments needed. "We've had tons of people ask us if it's safe to drink, if it will make them glow and so on," Romanow said. "But I enjoyed one and I'm not glowing. So I think it's safe to say that not only can you drink this beer, but you're going to want to." Follow Philip Marcelo at His work can be found at

Since first reported on October 2010 (EuroMed 2010, "Desalination for clean water and energy", 3-7 October, Tel Aviv, Israel), the large volume of diverse experimental results recently published on closed circuit desalination (CCD) technology reveal new state-of-theart technology of high recovery; low reverse osmosis (RO) energy in the absence of energy recovery; reduced scaling and fouling with a wide range of operational flux without exceeding membranes' test condition specifications and flexible online control of all principle parameters in desalination processes independent of each other; of unmatched performance characteristics compared with the widely practised conventional plug flow desalination methods. In order to realize the scope and prospects of the new CCD technology on the basis of its performance characteristics which appears to presently meet most, if not all, long-term (20 years) targets of the growing worldwide desalination industry with high cost effectiveness, the present document provides an updated summary of all available results together with a critical evaluation in comparison with conventional Plug Flow technology. The results of this critical comparative study reported herein provide the desalination industry with a new technology ready for immediate application, which addresses essentially all beneficial aspects of RO. © 2012 Desalination Publications. All rights reserved.

A new method for continuous Brackish Water desalinated by a two-mode consecutive sequential process which incorporates closed circuit and plug flow desalination (PFD) techniques is exemplified with a commercial apparatus (named REIM-II) comprising 10 modules (8″), each of four elements (ESPA2+), with their inlets and outlets connected in parallel, and with recycled concentrate mixed with fresh pressurized feed admitted at inlet to modules. When the salinity of the recycled concentrate inside the closed circuit manifests the desired system recovery level, the apparatus switches from closed circuit to PFD by valve means until the entire brine in the closed circuit replaced by fresh feed, and thereafter, closed circuit desalination (CCD) resumed. CCD in said apparatus experienced most of the time with the same fixed flow rate of feed and permeate under variable pressure conditions; whereas, PFD takes place briefly only after the system attains its desired recovery level at a predefined pressure in order to enable replacement of brine by fresh feed without stopping desalination. Replacement of brine by fresh feed takes place with enhanced feed flow under reduced pressure with a lower momentary recovery in order to expedite the process and minimize brine energy losses. The new method is exemplified by the commercial operation of the REIM-II unit with feed of 6800 μS cm-1 according to conditions as followed: CCD Mode: 35 m3 h-1 flow rate of feed and permeate (≈19 lmh); 36 m3 h-1 flow rate of recycled concentrate; 1.1 bar of module pressure difference (Δp); and 17-25 bar of an effective variable pressure range. Plug Flow Desalination Mode: 45 m3 h-1 flow rate of feed; 16 m3 h-1 flow rate of permeate (≈10 lmh); 29 m3 h-1 flow rate of rejected brine; 0.5 bar of module pressure difference (Δp); and 9 bar average pressure. Overall Performance: 30.7 m3 h-1 average flow rate of permeate; 37.04 m3 h-1 average flow rate of feed; 82.9% recovery; 28.83 kW power consumption; 0.94 kWh m-3 specific energy with 61.5% efficiency of the high pressure pump; 20 min total sequence duration with 65% of the time experienced with CCD, 20% experienced with PFD, and 15% experienced during transitions between cited modes. The commercial REIM-II unit has been operated continuously over the past 20 mo and produced some 400,000 m3 permeates with 88-80% recovery in the respective feed salinity range 5800-8900 μS cm-1. © 2012 Desalination Publications. All rights reserved.

Brackish Water sources of 6800 and of 4000 μS cm-1 were desalinated in closed circuit by single stage consecutive sequential process with 80% and 88% recovery, respectively, using an apparatus comprising eight modules (8″), each of four elements (ESPA2+), with their inlets and outlets connected in parallel, wherein recycled concentrate mixed with fresh pressurized feed admitted at inlet to modules. The exemplified apparatus, named REIM-I, was operated with fixed permeate flow under variable pressure conditions and the brine in the closed circuit was occasionally replaced by fresh feed through the engagement a side conduit and this without stopping desalination and without any energy loss. The operation of the REIM-I unit is exemplified with 80% recovery of a high salinity (6,800 μS cm-1) feed source at fixed flux of 19 lmh; fixed permeate flow of 24.4 m3 h-1 (586 m3 d-1) of an average 625 μS cm-1 conductivity; a variable pressure range of 11-22 bar with an average of 17.7 bar, and an overall specific energy consumption of 0.82 kWh m-3 with high pressure pump efficiency of ≈55%. The operation of the REIM-I unit is also exemplified with 88% recovery of a medium salinity (4000 μS cm-1) feed source remove off at fixed flux of 27 lmh; fixed permeate flow of 35.0 m3 h-1 (840 m3 d-1) of an average 482 μS cm-1 conductivity; a variable pressure range of 12-21 bar with an average of 16.2 bar, and an overall specific energy consumption of 0.80 kWh m-3 with high pressure pump efficiency of ≈60%. The new technology under review, which enables the attainment of any desired recovery made possible by the constituents of the source in the presence of suitable anti-scaling agents without any loss of brine energy, has been operated commercially for the past two years continuously providing some 400,000 m3 of permeates under 1300 μS cm-1 for irrigation in the dry Negev district of Israel. The application of the new technology for Brackish Water desalination of high recovery and low energy, reported herein for the first time, was recently demonstrated to allow desalination of Mediterranean Water (4.1%) with a record low RO energy (1.85 kWh m-3, 13 lmh flux, and 85% efficiency of high pressure positive displacement pump) which manifests energy saving of ≈30% compared with the reported RO energy consumption of large desalination plants equipped with modern energy recovery means. © 2012 Desalination Publications. All rights reserved.

Stover R.L.,Desalitech
Desalination and Water Treatment | Year: 2013

Closed Circuit Desalination (CCDe) technology is an emerging platform for reverse osmosis (RO) water treatment and desalination. It lowers the feed pressure requirement, improves the membrane performance, increases the operational flexibility, and eliminates the need for energy recovery devices using only standard RO equipment. For industrial water treatment and brackish water desalination applications, CCD technology achieves maximum recovery in single-stage units while saving energy. Alternately, a CCD unit can be added to a conventional RO process to concentrate brine and raise recovery. Over 97% recovery has been demonstrated in a single-stage operation. The recovery rate of a CCD unit can be adjusted at the control panel without modification of system hardware, limited only by the scaling characteristics of the feedwater. Maximum recovery operation and high flexibility have significant cost-cutting implications for industrial water treatment and inland brackish desalination, where both feedwater supply costs and brine disposal fees can be significant. CCD systems also demonstrate excellent resistance to fouling and scaling. Cross-flow supplied by a circulation pump washes the membranes, and salinity cycling disrupts and greatly reduces the scaling and fouling. Short membrane arrays and high cross-flow allow the CCD process to operate at higher average fluxes than conventional RO processes, without exceeding the membrane manufacturer's flow or recovery specifications. This paper describes the design and modeling of high-recovery CCD processes and compares the measured and calculated specific energy consumption levels to validate modeling methods and tools. Two brackish water RO cases are considered: one using Desalitech's seawater reverse osmosis-CCD (SWRO-CCD) process and the other using its hybrid plug flow desalination-SWRO-CCD (PFD-SWRO-CCD) process. CCD systems are compared favorably to conventional RO trains modeled with the same feedwater, high-pressure pumps, and membranes operating at the same average flux and overall recovery percentage. © 2013 Desalination Publications.

The retrofit technology utilizes pressurized brine of convention RO to feed a Closed Circuit Desalination (CCD) unit; wherein, further desalination takes place to a desired recovery level. The application exemplified in FIG. 4 is of a retrofit unit comprising a Booster Pump (BP2) for raising pressure of inlet feed; a Circulation Pump (CP) for creating cross flow over membranes (E) in the pressure vessel (M), thereby enable efficient RO desalination; an Actuated Valve (AV) in line with a partially open Manual Valve (MV) to enable periodic replacement of high salinity concentrates with fresh feed without stopping desalination; No Return (NR) valve means to control the direction of flow in the system; and monitoring means such as of electric conductivity (CM) and flow (FM). Periodic replacement of high salinity concentrates by fresh feed initiated at desired high system electric conductivity and terminated at a desired low system electric conductivity, while desalination continued.

An apparatus for continuous closed-circuit consecutive sequential desalination of a salt water solution by reverse osmosis that comprises a closed circuit system comprising one or more desalination modules having their respective inlets and outlets connected in parallel by conducing lines, each of desalination modules comprising of one or more membrane elements, a pressurizing device for creating counter pressure to enable reverse osmosis desalination and replacement of released permeate by fresh, a circulation system for recycling the desalinated solution through the desalination modules, a conducting line systems for permeate collection from the desalination modules, a conducting line system for removing brine effluent a valve system to enable periodic discharge of brine from the closed circuit without stopping desalination,; and monitoring and control systems to enable continuous closed circuit desalination of desired recovery proceed in consecutive sequential steps under variable or constant pressure conditions.

News Article | September 30, 2015

Just how dirty is the Charles River? Nadav Efraty, the chief executive of Newton-based water-purification company Desalitech, has definitely seen worse. “You wouldn’t want to go out and drink it,” Efraty said. “But you could bathe in it.” If you’ve got the right equipment, you can even turn it into beer. That’s what Desalitech did for Harpoon Brewery, which used 300 gallons of purified river water for its limited-edition Charles River Pale Ale. The two companies showed off the new brew Wednesday in advance of HUBweek, a new arts and ideas festival co-produced by The Boston Globe. Water quality in the Charles has improved considerably from the days when it inspired hit songs paying tribute to Boston’s infamous “Dirty Water.” In recent years, brave souls have even taken a dip in the river. But despite those advancements, using the Charles for human consumption required some heavy-duty technology. Desalitech uses industry-standard reverse-osmosis filters, which force out impurities by pushing polluted water past a series of membranes under very high pressure. In a typical industrial purification system, water is pumped past several sets of filters in one long pipeline, Efraty said. Desalitech’s system shrinks the entire operation down by running the water past one set of filters in a continuous loop, purging the briny leftovers once enough clean water has been extracted. That allows Desalitech’s system to be more efficient in its use of both electricity and water, Efraty said. Instead of gettting three clean gallons for every four run through a typical water-purification system, Desalitech said it can recover 19 of every 20 gallons. The company relocated its headquarters to the Boston area from Israel two years ago and has seen its customer base swell to include big names like Coca-Cola and Southern California Edison, according to Efraty. Many of the jobs Desalitech tackles, such as treating industrial wastewater, are a lot tougher than cleaning up the Charles, he noted. “It’s pretty easy,” Efraty said Wednesday. “We usually deal with much more problematic sources.” The water was drawn out of the Charles using pumps, put into tanker trucks, and driven to Chicago, where Desalitech runs a treatment system. Once purified, it was loaded up and trucked back to Boston, where it was pumped into the beer-making tanks. At Harpoon, the idea of using Charles River water – rather than the company’s typical municipal Boston source – raised a few eyebrows around Harpoon headquarters. “I was like, `Really? Well, that’ll be interesting,’” said Sean Cornelius, Harpoon’s head brewer. The whole idea amused Harpoon president Charlie Storey, who grew up around the Charles. “We were always advised that if you happened to fall in the river, you had to go to the emergency room immediately afterward,” Storey said. “So the idea of taking Charles River water and using it to make beer, there’s just a tremendous sense of humor and a sense of irony about it.”

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