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Brackish Water Treatment Becoming more Affordable…

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Brackish Water Treatment Becoming more Affordable with New Membrane Technology from Toray, Hydranautics, and FilmTec.

Brackish water treatment using new reverse osmosis membranes is quickly becoming a go to method for purifying water for human consumption. With new membrane technology being developed by Toray, Hydranautics and FilmTec, it has never been more affordable or viable to generate pure water using brackish water reverse osmosis (BWRO) systems. This has global implications for creating clean drinking water in both a cost effective and sustainable way. Municipal water treatment facilities all over the U.S. are now using or considering implementing brackish water treatment systems that use the latest technology in reverse osmosis membranes developed by Toray, Hydranautics, and FilmTec. It is likely that BWRO systems will supply a significant portion of their water requirements as access to fresh water becomes more difficult. As this technology becomes more efficient and more cost effective expect more municipal water treatment facilities and countries around the world will implement customized BWRO systems.

Brackish water is water that contains more dissolved salt than fresh water but less than salt water; usually measured in the .5-30 g/l of salt range. Most forms of brackish groundwater are easily handled by brackish water treatment methods using the latest reverse osmosis membrane technology. Brackish water is also found in estuaries and caused by human activities such as: dikes, coastal flooding, and waste from salinity gradient power processes. It is important that industry properly utilizes brackish water treatment protocols as it can be damaging to the environment. The new BWRO systems can effectively rehabilitate this water for human consumption or responsible use in industry.

The recent technological advances in reverse osmosis membranes have made brackish water treatment more favorable for municipal water treatment facilities. The advances have rendered the BWRO process more efficient, while lowering capital costs and reducing energy usage. Where fresh water used to cost 50 cents per thousand gallons, it is now closer to $3-4 per thousand gallons due to demand (having to ship it from up to 100 miles away) and rising energy costs. Saline or brackish water treatment is now as low as $2-3 per thousand gallons for oceanside municipalities or $4-6 per thousand gallons for the inland organizations. A combination of rising fresh water costs and technological advances in reverse osmosis membrane technology has made BWRO an economically viable option that many municipal water treatment facilities are embracing.

Not only are brackish water treatment systems more cost effective from a capital standpoint but also from a working efficiency point of view. The new reverse osmosis membranes developed by Toray, Hydranautics, and FilmTec, are more durable, have a higher rejection of total dissolved solids (TDS), and higher flow rates. These improvements have increased the longevity of the reverse osmosis membrane at the same time as increasing the purity and speed of the overall BWRO system. Although it is unlikely to be the primary source of most municipal water treatment facilities, brackish water treatment is a cost effective way to supplement the growing demand for clean water.

Energy costs will continue to rise and the use of BWRO systems will become even more cost effective. A resource as finite as fresh water demands that innovation in water filtration and purification techniques improve and companies such as Toray, Hydranautics, and FilmTec, will be leading the way. Brackish water treatment is a great way to harness the advancement in reverse osmosis membranes to provide clean pure water for both drinking and industrial use.

ro pumps

RO Pumps and Motors…

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Reverse Osmosis System Efficiency: Pumps and Motors.

The global requirement for fresh pure water is driving innovation in the water filtration industry as a whole, but especially with the reverse osmosis (RO) process. Being one of the most efficient and cost effective ways to desalinate and create clean drinking water, innovation of the components of reverse osmosis systems are helping to make the process even more efficient and cost effective. The components that are making the most impact in driving the costs down and efficiency up, aside from the reverse osmosis membrane are the RO motors and RO pumps. The reverse osmosis process is a cross-flow technology and requires higher pressure, produced by RO pumps such as Procon Pumps, to ensure the highest efficiencies.

With the recent advancements in reverse osmosis technology specifically pertaining to energy recovery devices, the reverse osmosis systems are able to utilize the pressure and the flow of the rejected water to facilitate better efficiency. This allows assembles of the RO motors and RO pumps to be smaller and decreases the overall energy requirement for the plant. Using high efficiency motors, such as Marathon motors, and high quality pumps such as Procon pumps, allows there to be less strain on the reverse osmosis membrane.

Improvements in reverse osmosis membranes have allowed the RO systems to use smaller and more efficient RO pumps and RO motors to achieve the same output. The flow rate is an important aspect of the overall efficiency of the reverse osmosis system and it can be properly regulated with quality RO pumps, like Procon pumps. There are several factors that influence the recovery of the purified water consisting of: membrane size, membrane surface area, membrane pore size, temperature, and operating pressure.

RO pumps supply the necessary pressure to overcome the resistance of the salt that gets held back by the membrane and push water through the reverse osmosis membrane. Depending on how much salt that is being filtered the RO pumps and RO motors have to be adjusted to balance enough power to overcome the salt but not so much that it strains the membrane. Typical pressures required for brackish waters are 225 – 375 psi, whereas salt water reverse osmosis (SWRO) much higher pressures in the range of 800 – 1,180 psi. Using efficient RO pumps and RO motors can ensure that the total energy expended to purify even the densest salt water uses the minimal amount of energy.

In order to get the brackish groundwater to the surface for effective treatment with a reverse osmosis system, RO pumps and RO motor have to be able to draw the groundwater from hundreds of meters under the surface. The more efficiently that the brackish water can be extracted from the ground using the latest in pump/motor technology, the less energy the reverse osmosis system will consume.

The world requires pure clean water and reverse osmosis systems seem to be leading the way. By increasing the efficiency of all of the various components such as RO pumps and RO motors, the system designers can lower cost and improve the overall purification process. The latest innovations in pump and motor technology for the reverse osmosis systems are providing improved efficiency of the total reverse osmosis system, which provides better access to clean pure water for individuals and industry.

Boron Removal with SWRO…

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Water Contamination – Boron Removal with SWRO.

As the scarcity of fresh drinking water becomes a growing concern worldwide, new technologies involving seawater reverse osmosis (SWRO) systems, specifically innovation around their reverse osmosis membranes, are in focus with their ability to offer a solution. Although SWRO systems are already effective at removing over 99% of total dissolved solids (TDS) there has been growing concern in many locations over the effectiveness of removing one toxic element in particular: boron. With new guidelines for boron contamination levels in drinking water, traditional reverse osmosis membranes haven’t been a viable solution to this problem. New developments in SWRO membranes have been shown to increase the effectiveness raising it from 91% to 98% boron removal. In combination with a post-treatment process, SWRO has shown to be a cost effective way to reduce the boron and other TDS to acceptable levels for drinking water worldwide.

Boron is an element that is contained in a healthy body at a level of approximately 0.7 ppm. It is not considered an essential mineral for bodily functions but it is absorbed through consumption of plants or fluids. For the average person their daily intake is about 2 mg, which is well below toxic rates of 5g per day; where negative health effects begin. Amounts exceeding 20g per day are considered to be the fatal toxicity limit. Both the World Health Organization (WHO) and the European Union (EU) have set standards for Boron in drinking water at 0.5 mg/L and 1 mg/L respectively.

The boron contamination that is currently observed in seawater varies from about 4 to 5.5 mg/l, which is about ten times greater than the standards set by the WHO. Most of this toxicity can be attributed to agricultural fertilizers and coastal cities water treatment plants discharge; it is commonly added to soap and detergents. For years, most reverse osmosis membranes have only been able to reject 73-90% of the boron contamination, but with recent advancement from manufacturers, including Hydranautics, the newer high boron removal reverse osmosis membranes can achieve a 94-98% rejection rate. Coupled with this advancement in new membrane technology there has also been research that analyzed the various pre and post-treatment options to optimize the efficiency and cost effectiveness of the SWRO process.

To make the SWRO process most cost effective and still meet all of the boron contamination guidelines there are a few different methods that have been tested and implemented with great success. If the initial salt water is beyond the capabilities of the new reverse osmosis membranes, then a combinatory process of mixing brackish water reverse osmosis (BWRO) that is treated to increase the pH to a 10-11 level of alkalinity with the initial salt water is required to achieve the desired boron rejection rate. By mixing this alkaline-BWRO and high boron removal reverse osmosis membranes people can meet the boron contamination guidelines and remain cost effective. Often this is not necessary as the new high boron SWRO membranes, made by Hydranautics, can effectively remove enough boron contamination on its own, as long as the initial water conditions are within an acceptable range.

These advancements in reverse osmosis membranes, especially related to removing boron contamination by SWRO, have afforded many companies and municipalities access to affordable clean drinking water. As more people need access to clean pure water for personal consumption and industrial use the advancements made by Hydranautics, and other reverse osmosis membrane manufacturers, will allow the SWRO process to become an option for even more municipal water treatment facilities.