Consumers don’t often think about the fact that their electric power, clothes and even the semiconductors that go into the chips for computers and cell phones are manufactured using massive amounts of water. In fact, in 2013, private industry was responsible for 65% of freshwater withdrawals. While increased concern about climate change has successfully led to declines in electricity use in the U.S., industry continues to be as inefficient with its water use today as it was 20 years ago.
“What little public awareness there’s been on water conservation has focused on steps families take in their homes: shorter showers, shrinking their lawns, flushing the toilet less frequently. Industry basically has been mirroring those steps: tightening valves and reducing the use of high pressure hoses in cleaning applications. These are certainly important, but are simply a first step in how we can minimize water waste,” says Nadav Efraty, CEO of Desalitech.
A UNIQUE PROJECT
That’s where a groundbreaking reverse osmosis water purification technique comes into the picture, and why the company embarked upon a unique project to make large-scale water purification more understandable: They extracted and purified 4,000 gallons of water from the Charles River in Boston. Less than two decades ago, this river saw such severe raw sewage pollution that it failed state swimming standards for 80% of the year.
That clean water went to six breweries around the Boston area. Each developed a unique beer to participate in the 2016 Brew the Charles contest at HUBweek, a weeklong celebration of creativity and innovation in Boston. The event was built on Harpoon Brewery’s 2015 signature beer made with Desalitech-treated Charles River water.
“We wanted to illustrate how our groundbreaking technology works, in a way that would be fun and memorable. So, we thought, why not see what some of our favorite local breweries come up with?” Efraty said.
This water transformation is accomplished using an innovative new reverse osmosis technology that is widely becoming adopted by industry. Unlike traditional reverse osmosis systems that use a “one and done” process, this new solution recirculates the water across the membrane array and increases the recovery with each concentration cycle. In traditional steady-state reverse osmosis configurations, recovery, crossflow and flux are coupled, which limits flexibility when trying to optimize system performance. As a result, traditional reverse osmosis is historically more expensive, inefficient and unreliable.
But in this CCD (closed circuit desalination) process, these operating conditions are independently controlled set-points at the control panel. The recovery is a function of the brine flush valve actuation trigger—a combination of maximum pressure, brine concentration and volumetric recovery. Flux is a function of the high-pressure pump, and crossflow is a function of the low-horsepower circulation pump.
VALVES PLAY A ROLE
system where the valves are located.The process uses a variety of valves in many sizes, which depend on the application of a particular solution and the places within the
To prevent a potential catastrophic backflow—such as backflow that would occur immediately downstream from a pump—the system uses 3- and 4-inch check valves with pressure ratings of 150psi and 300psi.
Reduced port ball valves in small sizes (one-half, three-quarters and 1 inch) are used to enable water sample collection by system operators.
Ball (3-piece) and butterfly valves are regularly paired with pneumatic actuators for automated control throughout this system. For example, these are valves that control the feed, recirculation and brine outlet flows. The automated control of these valves drives the CCD technology that enables these systems to recover as much as 98% of water from even the most challenging water sources—resulting in pure, potable water.
Participating breweries included regional leaders like Samuel Adams, Harpoon Brewery, Castle Island Brewing, Idle Hands Brewing, Cape Ann Brewing and Ipswich Ale Brewery. Over 1,000 people attended the closing party for HUBweek, where they had the opportunity to taste all the beers made from Charles River water, which was tested and proven to be purer than Boston tap water.
For Boston beer lovers, the proof was in the tasting. For the Brew the Charles contest, Ipswich Ale’s beer won the judge’s blind taste test, but Norwood, MA-based Castle Island Brewing Company developed a dry hopped cream ale that founder Adam Romanow said he hoped would “let the water shine through.” It did, and Castle Island’s ale was selected to win the People’s Choice Award at HUBweek in 2016.
“We live in a world where water is increasingly scarce,” noted Efraty. “The public needs to understand how innovative reverse osmosis technology will transform the future of water.”