Introduction
In this edition of the Vibes Newsletter, explore how VSEP® membrane technology is driving breakthroughs across multiple industries. The issue begins with advances in acid purification, highlighting single-step recovery even in challenging chemistries. It then shifts to the urgent topic of drinking water contaminants such as PFAS and parabens, and how new treatment strategies are evolving to meet these challenges. Readers will also find insights into water scarcity and reuse, including how industrial and municipal systems are adopting higher-yield filtration to counter shrinking water supplies. Another feature covers how a major engineering firm selected VSEP for brine management and zero liquid discharge (ZLD) at a municipal water reuse site. The newsletter concludes with a look at how VSEP is gaining traction in mining applications, providing effective solutions for difficult effluents and tailings water.
Purifying Dirty or Spent Acid with VSEP
The use of Polymeric membranes has been studied for many years for purifying acid. Nanofiltration membranes are desirable because they can allow clean acid to pass and can reject multivalent ions and contaminants. With Nanofiltration (NF), the passage of most acids is nearly 100%, while the rejection of contaminant metals and organics is high. The problem with using conventional spiral membrane elements is that they cannot handle suspended solids and are limited by the solubility of sparingly soluble salts such as Calcium Sulfate. VSEP does not have these limits and can filter the acid in a single step producing clean acid that can be recycled instead of discharging it to the leach pond.
NF membranes typical are sized to have rejection capabilities of between 150 and 800 Daltons. Ionic charge is also a factor in the rejection. So NF membranes will have good rejection for Divalent and Trivalent ions, especially metals and hardness. Organics and TOC tend to be larger as well and so humic and other organic materials can be removed with NF.
During membrane filtration, materials dissolved in the feed water are convectively driven to the membrane surface where the concentration of these materials increases to very high levels compared to the level in the liquid away from the membrane. This is known as concentration polarization and a boundary layer of highly concentrated dissolved solids forms near the membrane surface. Because the formation of the concentration polarization boundary layer results in increasing concentration of dissolved solids near the membrane surface, the osmotic pressure or pressure needed to be applied to for liquid passage increases. In addition, this region that has higher than normal levels of sparingly soluble salts may be subject to crystallization and scaling in very close proximity to the membrane surface. Therefore, the use of static or crossflow style spiral membranes will suffer from reduce flux rates and increased fouling with time. The shear generated with VSEP eliminates this concentration polarization and improves the flux rate and scaling resistance.
New Logic has done acid purification using NF membranes for Boric Acid, Phosphoric Acid, Sulfuric Acid, and Hydrochloric Acid. When the acid strength is high, we use our special acid resistant NF membranes that can even handle 30% acid. New Logic has deployed its VSEP technology many times to study the performance during filtration of Phosphoric Acid. Each case has had different objectives. In one case, the desire was to remove organics (TOC) as an alternative to calcination. In other cases, the desire was to remove heavy metals and toxins to improve the quality of fertilizer products. Another possible use is to remove Uranium and concentrate it to the point where recovery using selective ion exchange can be a method of Uranium recovery and production.
Multiple passes through the same NF membrane may results in additional reductions. However, the use of membranes cannot reach the purity level required for food grade. NF membranes can be used though to increase the purity of lower grade acids and can make the mining of poor phosphate deposits more economical. Some ore deposits may not even be suitable for processing as the lowest grade Phosphoric Acid due to impurities. However, with NF filtration, these deposits can be processed. Phosphoric Acid is typically produced at a concentration of 54%. Very high pressure is needed to get filtration to occur at that concentration. This acid can be diluted to between 18% and 30% where a more reasonable feed pressure of 500 psi (34 Bar) can be used. The lower the Phosphoric Acid concentration, the lower the osmotic pressure and the higher the flux rate will be. The dilute acid can then be sent to an evaporator to increase the concentration as desired.
What is in the water we drink?
Testing of drinking water includes a few dozen natural inorganic chemicals as well as some man-made chemicals and organic materials. But there are potentially many thousands of chemicals that can end up in our drinking water. Only recently, it was observed that fluorinated chemicals known as a group as PFAS are found in 7000 municipal drinking water systems in the United States. These chemicals are suspected of causing cancer and other health issues. New regulations are currently being formulated. But, even with the discovery of these chemicals in our water, it is only the tip of the iceberg.
There is a chemical that all of us use or consume every day and I’m sure you have never heard of it. A group of chemicals called “Parabens” are used to sanitize products and food. Parabens are found in a wide range of everyday products including shampoo, skin cleaners, moisturizers, shaving gels, toothpaste, makeup and even foods like fruit juices, dressings, sauces, soft drinks, pastries, and many others. Parabens are endocrine disruptors.
Endocrine disruptors are chemicals that interfere with your endocrine or hormonal system by altering the synthesis, secretion, transport, binding, or elimination of natural hormones such as estrogen and hormones produced by the thyroid. There is a controversy about the safety of these chemicals with some groups calling for removing these from the market while regulators and other scientists calling for studies to determine which chemicals are a risk and at what levels.
Parabens can affect the levels of the thyroid hormone called Thyroxine, the main hormone produced by the thyroid. Parabens can also affect the levels of the thyroid stimulating hormone (TSH) that is produced in the pituitary gland to stimulate production of thyroxine. Abnormal levels of these hormones can influence weight, mood, body temperature, and metabolism.
Parabens are produced by the esterification of para-hydroxybenzoic acid with an appropriate alcohol such as ethanol or methanol. Parabens are active against a wide range of microorganisms. The mechanism for their antibacterial properties is not well understood. They are thought to act by disrupting membrane transport and by inhibiting synthesis of DNA and RNA. Consumer safety organizations have determined that Parabens are safe, but controversy exists as to their potential health impact.
Because these chemicals are consumed and used for body wash, they are eventually discharged to the environment. A study in New York found that wastewater can contain 176 mg/day/1000 people. When using a population of 8.5 million for the study area, this calculates to discharge of 546 kgs or 1,204 lbs of Parabens per year. Conventional wastewater treatment plants are able to break down the chemical and can remove 92-98% of parabens and paraben derivatives prior to discharge. The EPA has studied these paraben breakdown derivatives and found that they have the ability to adhere to organic portions of sediment and can bioaccumulate and persist in the environment.
Chlorinated parabens have a removal rate of only 40% during standard wastewater treatment. Multiple studies have shown that chlorinated parabens are endocrine disruptors and mimic the effects of estrogen. Chlorinated parabens will continue to impair microorganisms such as daphnia and various algae when released to the environment. Parabens and its derivatives will be in small concentrations when discharged compared to what we all consume every day. But these will bioaccumulate and if it later found that they are not safe to consume, they will be hard to get rid of. Because wastewater treatment plants discharge to surface waters, this will come back around as drinking water. There is currently no testing done for these chemicals in drinking water.
Water Scarcity Continues
California has not built a new reservoir to store drinking water in decades. One of the largest water projects ever undertaken in California is the California Aqueduct that travels North to South along the eastern edge of the San Joaquin valley. Massive amounts of water are pumped out of the Sacramento delta from the Clifton forebay into a 400 mile long aqueduct reminiscent of Roman times. There have been a few problems with this water diversion. First, removing that much water changes the habitat of the wetlands in the delta. Also, the freshwater/saltwater gradient has moved inland as More water is needed for Southern California because of the growing population and also because of new water allocation reductions of water coming from the Colorado River. There are other surface water sources possible, but no work has been done to create new reservoirs.
One proposal that has been talked about for a long time is to build two massive tunnels 40 feet in diameter to carry water from the Sacramento River near the town of Hood, just south of Sacramento and then bypass the delta and deliver this water to the Clifton Forebay for introduction into the California aqueduct system. The project is estimated to cost $20 billion dollars. But as with other projects like this high speed train project in the central valley, the actual cost could be double that amount. The two tunnels would be 30 miles in length and would pass under the delta at 150 feet below ground. The project would be paid for by revenue bonds and the bond payments would be made by farmers and those who would benefit from the project. So voter approval is not required. This project would be larger than the English Channel Tunnel or the Boston Big Dig. The English channel project was originally estimated to cost about $5 billion dollars, but when complete was 80% over budget. The Boston highway project was originally estimated to cost $2.8 billion dollars and when finished actually cost over $14.6 billion. The population in California is now nearly 40 million and has increased by 5 million since 2000. But the water infrastructure has not kept pace with this increase. California has also been removing dams with storage capacity to improve fish habitat. It can take decades to build new infrastructure since any project will face almost unlimited lawsuits from environmental organizations. One simple solution that has not been addressed that much is water reuse. Instead of using water once and then throwing it away, recycling water and recovering it from effluent could help a great deal
New Logic has installed many projects in California and elsewhere to treat industrial effluent to make clean water for reuse. One category of this includes treating the brine blowdown for cooling towers used at power plant. Another category is with bottled water plants that filter town water or ground water using conventional spiral RO membranes. Because of solubility limits, these system can only recover about 75-85% of the water they consume. This leaves a huge volume of brine concentrate that is wasted. New Logic has installed its VSEP system at one Southern California bottling plant where the brine is filtered using VSEP RO resulting in an overall recovery of 98%.
What AI says about FGD and Spiral RO
Coal fired power plants face strict air and wastewater emissions. Today most environment agencies require a power plant to fit a wet flue gas scrubber to clean emissions. These scrubbers can remove 80-90% of the SOx. This process is called flue gas desulfurization or FGD. As this is a wet process the pollutants are trapped in FGD purge wastewater. This wastewater contains mostly Gypsum with some market value, but also a wide variety of pollutants from heavy metals including Arsenic, Mercury, and Selenium
The New Logic Research VSEP RO membrane system can treat this effluent and reduce both capital and operation costs when used before evaporation. The VSEP can also be used to polish the condensate from the evaporator so that all treated water meets discharge requirement. The cost savings both in capital cost and operating costs are enormous. It takes 627 kWh of equivalent heat to evaporate 1 m3 of water. But, it takes only 7 kWh to remove 1 m3 of water using the VSEP RO as pretreatment. It makes sense to use VSEP to remove water as far as possible with the remaining concentrate going into an evaporator. While the EPA has designated the VSEP RO system as a Best Available Technology, there are some in the engineering community who are proposing to us conventional spiral RO membrane systems. The vibration and shear that comes with the VSEP filtration helps to avoid fouling and plugging. Recently, our founder, Brad Culkin submitted a question about this to the Grok AI program and got this simple non-partisan response:
“Testing of spiral-wound membrane modules for FGD wastewater treatment reveals significant challenges, including fouling and scaling, limited salt rejection at high TDS, pH and temperature sensitivity, organic and heavy metal fouling, high energy consumption, cleaning difficulties, and pretreatment dependency. While RO membranes like the SWC 2540 show promise with proper pretreatment, achieving >97% salt rejection and low conductivity permeate, their practical application is hindered by operational and economic constraints. Integrated systems combining RO with and evaporator are often necessary to approach ZLD and meet stringent discharge regulations.”
This graph shows the flux rate over time for a spiral RO membrane filtering FGD Effluent. It baselines at about 2 LMH (1.2 GFD) in less than 2 hours. Since 2009, New Logic has been working on the FGD solution. With the new rules on discharge taking place, New Logic has been very busy with power plant customers. New Logic has now pilot tested 14 different power plants to treat FGD effluent. In addition, we have provided 17 other system quotations. All of these projects are in various stage of development. Orders for some of these systems have already been received and are in fabrication at New Logic’s factory. New Logic installed its first VSEP RO FGD project more than 10 years ago.
Leachate – The Achilles Heel of Landfills
When people think of landfills, they mostly think about the smell, dust, and birds. Leachate management is a little mentioned problem. But landfill operators know well the difficulty. Most landfills currently haul the leachate using contractors who transport it to a municipal sewage treatment plant for disposal. There are rules for the amount of leachate that can accumulate at the bottom of a lined landfill. There are also rules for managing onsite leachate storage. All of this can be a big headache for the operators. The tiny State in New Hampshire is working on some of these issues after some local landfill leachate problems.
In New Hampshire, in the small town of Bethlehem, Casella Waste Systems was having trouble with compliance. In 2021, they had an accidental release of 154,000 gallons of leachate that overflowed but did not get past a surface water detention pond. The pond was designed for surface water, not for leachate. After this an environmental group thought that this polluted the Ammonoosuc River and this led to a settlement that was painful. Another New Hampshire landfill in Lebanon operated by the city was cited for leachate breakouts including 5 that went beyond the facility into the environment. A landfill operated by Waste Management in Rochester had 13 leachate discharges A landfill in Conway operated by the city was accepting liquid waste which was not allowed.
The Bethlehem landfill is required to keep the leachate level at the liner at or below 12”. In one recent incident, the level was measured at 116”. Over a 2 year period from 2021 to 2023, they had pumped out and hauled 2.8 million gallons. But during the second half of 2023, the volume increased to 5.2 million gallons for only 6 months. Managing all these problems can be a real headache. 5M gallons is about 1000 trucks of hauling in 6 months, or about 5-1/2 trucks per day. The installation of an onsite VSEP treatment system would not only save money on hauling costs, but it would reduce the risk of accidental releases.
As a result of some of these problems in the State, the New Hampshire House is working on a new law, House Bill 566, which will put tighter restrictions on landfills. Part of this new rule might require operators to submit a 20 year plan for leachate management to show how they will maintain leachate levels to below 12. Also mentioned in the discussions leading up to legislation is the problem of PFAS contamination and simply moving this to a sewage treatment plant is not a good idea.
Water Is Limited, The Population Is Not
The world population has doubled in the last 50 years and has tripled in the last 75 years. But the amount of fresh water available hasn’t changed in millennia. Water covers 71% of the planet’s surface, but 97% of the water is seawater with high salinity. 2.5% of the water is frozen. Only 0.5% of the earth’ water is available as fresh water, but not all of that is drinkable. Water stress is growing in many areas. There have been drought conditions in some places where people are told they can’t wash their car or water their lawn. This is true even though only 8% of water consumed is for domestic use, 33% of water used is for agriculture and 59% is used by industry. 80% of water consumed is used for cooling power plants and agriculture.
Populations are also shifting to warm dry climates getting away from cold damp winters. But, these areas are often natural deserts and water is scarce to begin with. The southwestern United States and Northern Mexico is a good example. The two main rivers that supply water to 40 million people are the Colorado river and the Rio Grande (Big River). The mighty Colorado River starts in the mountains of Wyoming and traverses the landscape south through Utah, Nevada, California, and Arizona. Then is crosses the border and exits to the sea in Mexico. Recently, the Federal Government announced a tier 2 water shortage condition. This would require Nevada, Arizona, and Mexico to implement mandatory water cuts. Arizona is required to cut 21% of its allocation from the Colorado River.
In the early 1900s, there were no controls on water use from the Rio Grande and the Colorado and overuse became a problem on both sides of the border. So, in 1944 a treaty was established between Mexico and the United States that set boundaries for water use. From reservoirs feeding the Rio Grande, Mexico would supply 1.75 million acre feet of water every five years to farmland in Texas. In return, the US would supply 1.5 million acre feet of water to northern Mexico including Tijuana. While the Rio Grande start in Colorado, several tributaries feed into it from Northern Mexico. These tributaries have reservoirs to store water and this is where the water deliveries are supposed to be made to Texas. But the water deliveries have fallen way short of the 1.75 million acre feet. The reason is that the water is just not there. The two main reservoirs are the Amistad and Falcon and both are only 7% full.
Allocations from Mexico to Texas are being cut and allocations to Northern Mexico and Tijuana are begin cut from the Colorado River. New Logic has been contacted by several companies in the Southwest who are facing water allocation cutbacks as a result of the new government order. This has included a Coca Cola facility in Tijuana Mexico. They currently use a RO spiral system to treat the water that is used for bottling. But, they throw away a significant amount of the water that the spiral system rejects. A VSEP system can help them to get a higher yield from the water they receive. So they can cut their water intake by 20%, but still produce the same amount of treated water for use in the bottling process. New Logic has installed several systems in the Southwest for companies who recycle their effluent. This includes a truck wash in the central valley, a wafer fabrication plant, a power plant, a winery, a casino, a refinery, and a large bottled water facility in Rialto. Much more of this will be needed in the future as water restrictions will increase.
CH2M Hill Selects VSEP as best Brine Management
Big Bear Valley is a ski resort area in the mountains 100 miles east of Los Angeles. This area sources drinking water from groundwater wells. During periods of drought and high activity, the demand for water can surpass the supply. CH2M Hill, led by Jim Lozier, was hired to evaluate options for boosting water supplies. The method selected was to treat the local municipal effluent using advanced technologies to recharge the groundwater aquifer. The local wastewater agency processed about 2.2 MGD and this would be the source for the study.
The main part of the treatment process involved using Ultrafiltration (UF) to remove suspended solids and micro-organisms. Then the UF permeate would be filtered using a conventional spiral reverse osmosis (RO) system to make very clean water. To sanitize the water, it was passed through a UV system and then had hydrogen peroxide added. A carbon filter was used as the final step to remove trace contaminants and the residual hydrogen peroxide. This is all standard stuff. But, the problem was that when treating 1.17 MGD of reclaimed water with this process, there would be 160,000 gpd of brine reject that is left. This would need to have a home.
A pilot test was proposed and the technologies to be evaluated included Evaporation ponds, constructed wetlands, Electrodialysis reversal (EDR), VSEP RO, Hero RO, and Thermal Evaporation. The wastewater that is normally treated and discharged was piped to farm land lower in the valley to irrigate alfalfa fields. This would not be an option for the spiral reject because of the high TDS and chlorides, so some other treatment method was needed.
The final report concluded that to be able to use an evaporation pond the brine would need to be transported by a new pipeline to the lower Lucerne valley. This was deemed to be very expensive and permitting would be almost impossible. Constructed wetlands would have issues of Selenium and other bioaccumulating pollutants that would affect migratory birds. EDR was considered not suitable because it would not remove particulates, poorly ionized solutes, or pathogens. The Hero RO system is a very complex combination of several technologies to pretreat the water before standard spirals can be used again. The report concluded that this option was not viable because it requires a lot of chemical addition, is complex, requires a very skilled operator, and has relatively high capital and operating costs.
None of the above options were pilot tested. But, VSEP was pilot tested at Big Bear. The results of testing showed that the VSEP could volume reduce 160,000 gpd and would leave only 24,000 gpd of final concentrate. It was concluded that the VEP RO permeate could be blended with the spiral RO permeate, but until VSEP was approved by California for Title 22 groundwater recharge, the permeate would be blended with the excess treated municipal effluent that was sent for irrigation.
The report concluded that “VSEP combined with effluent mixing and evaporation is the best alternative for concentrate management.” By adding the VSEP RO to the Spiral RO. The overall recovery was 98% and this means that disposing the last 2% of brine becomes much easier.
VSEP has many uses for Mining
Because VSEP is not limited by solubility, pH, or suspended solids loading, it can tackle many mining applications where precise molecular separations are needed. VSEP is used for acid purification, solution mining, tailings water treatment for discharge or reuse, and many other applications. The online magazine, Inside Mining will be publishing are article about the Nolans Rare Earth mine in Australia where VSEP will be used to purify acid. New Logic has taken a full-page ad that will be placed near this article.
VSEP Pilot Testing Options
Pilot testing can be a very effective way to demonstrate the VSEP technology to the client and to confirm the actual performance that can be achieved. Many of our customers have read the literature about the vibration of the membrane, but seeing is believing. The LP VSEP is a small scale VSEP that has about 1.5 m2 of membrane area and can be used for collecting data that will scale up to much larger systems.
The LP VSEP is about the size of a small refrigerator and has wheels on the frame. The equipment can be set up in about an hour. New Logic ships these pilot machines all over the world and our engineers travel to each project to get the equipment running and to train the people using it. In addition, many of our international distributors have pilot machines and conduct pilot trials. While most of our onsite pilot tests are done using the LP VSEP, we do have five sizes available to rent including our largest i-84 VSEP. The LP Pilot machine has about 16 square feet of membrane. We also have a P-50 which has 50 square feet. For full-scale industrial sizes we have the i18 with 200 square feet and the i36 with 500 square feet. The largest VSEP is the i84 and this has 1400 square feet or membrane area. The LP VSEP is the least expensive to rent and is very easy to set up and start running. The larger VSEP rentals will require a bit more effort and larger tanks for processing.
We have recently installed a full-scale pilot at a large EV car company in their wastewater area. There are a few applications that will be tested. One of these is volume reducing the reject from a conventional spiral RO system. As with many inland locations, Sewer discharging brine is a problem because it can increase the salinity of rivers where the treated effluent is discharged. This large facility will be trying to reduce discharge and will be looking for ZLD. The reject from the VSEP will be hauled or evaporated. So minimizing this volume will be critical to reducing costs. An initial mass balance projection shows that we estimate a 95% reduction in the volume of spiral reject when using the VSEP. This is what the full scale pilot will be confirming during testing over the next several months.