Archive for the ‘Dealer Dynamics’ Category
ElectroSoft – softening without salt
Smart business owners and managers understand that innovation is essential to business longevity and prosperity. In a successful water treatment service company, it is imperative to understand, deploy and maintain cutting-edge technologies to help provide customers with better water.
As we continue to see more misguided attempts at softener bans and a continued emphasis on minimizing our net environmental impact, the need for more environmentally friendly water quality improvement technologies becomes glaringly apparent. Progressive manufacturers have deployed technologies like fractional brining, twin-tank sensor technologies and other innovations that dramatically reduce salt consumption for water softening use to effectively address these concerns. While our industry continues to document and prove that salt-based ion exchange softening has a positive environmental impact, our customers are clamoring progressively louder for salt-free solutions to their hard water problems.
Salt-free softening has been the ’holy grail’ of the water treatment industry for a number of years. The performance criteria for salt-free softening systems are twofold:
- The device must be capable of delivering an effluent hardness level <= 1gpg (17.4 ppm).
- The device must not use any salt (sodium or potassium) in the process of softening the water or when cleaning/regenerating itself.
Currently, the only practical and effective salt-free softening technologies are membrane separations and the electrolytic removal of hardness ions. The purpose of this article is to briefly introduce certain electrolysis technologies and their potential for use in residential applications.
Benefits of EDI
There are many benefits to using an electrolysis technology over traditional ion exchange:
- Simple and consistent operation
- No regeneration chemicals
- Few or no moving parts
- Uniform operation at varying water pressures and water chemistries
Electrodeionization (EDI) is a simply brilliant concept: Water containing ionic impurities is passed through a deionization chamber that contains anionic resin, cationic resin and two electrodes, each separated by semi-permeable membranes of alternating polarity. The electrodes attract ions unidirectionally through resins and out of the feed water stream, which then becomes purified. A concentrated stream of removed ions and water is continuously discharged to drain. Since the electrodes are continuously energized, electrolysis liberates hydrogen and hydroxyl ions from the purified water, donating regenerative ions to the resins and enabling the process to continue indefinitely.
EDI has been used successfully for many years as an effective alternative to acid/alkali deionization. IT is particularly sensitive to sediment, silica, chlorine and calcium carbonate hardness, all of which will interfere with the device’s ability to clean water. Traditional EDI technology is not therefore, generally suitable for use as a softening device. EDI is the technological springboard that has allowed inventors to develop other more appropriate technologies for residential salt-free softening.
Capacitive deionization (CDI) employs electrodes separated by the raw water stream. When the electrodes are charged with DC electricity, they attract inorganic ions from the water and hold onto them with varying degrees of effectiveness, depending on their molecular weight and ionic charge. The electrodes eventually reach their maximum capacity and then need to be cleaned by discharging and reversing electrical polarity. Reversing polarity causes the electrodes to actively repel the ions that they were previously attracted to. This intermittent or ‘batch’ regeneration saves water and energy while reducing capital outlay on equipment materials, as well as allowing for a smaller installation footprint. CDI typically recovers at least 80 percent of the water that it treats, compared to 50-70 percent for most membrane separation offerings.
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| CDI in Service | CDI in Regeneration |
The following should be considered when deploying CDI technology:
While feed water conductivity equivalents (FCE) do not usually need to be calculated for residential applications, influent water should still be tested for hardness, iron, silica, sulfates, conductivity, and alkalinity. Test data must be compared to manufacturer’s specifications to ensure compatibility and appropriate pretreatment.
- Low TDS output water can potentially create corrosion issues, so the product water needs to be TDS-controlled to ensure an output water quality that is compatible with household appliances, faucets and fixtures while still being soft or at a level of calcium hardness that is acceptable to the end-user.
- Any technology that employs electrolysis will produce gases as a byproduct, most notably oxygen, hydrogen and chlorine. These gases need to be safely vented or neutralized.
- A reliable, unswitched electrical supply must be located conveniently to meet the electrical requirements of the appliance. Unlike a traditional salt softener, CDI systems do not soften during power failures, so an uninterruptable power supply (UPS) might be considered in applications requiring a continuous supply of softened water.
- A code-compliant drain must be provided to allow discharge of drain water during a system cleaning cycle.
- A needs analysis should be performed to understand the flow demand in the home. Based on flow demand, the savvy dealer can deploy multiple processors or even utilize retention or blending tanks to provide the required amount of water.
While CDI is a promising technology for water softening, it is not economically viable as an outright replacement for traditional salt-based softeners yet. As large manufacturers embrace the technology and manufacturing processes improve, economics of scale will drive prices downward. As solar-energy production and hydrogen fuel cell technologies become more efficient and cost-effective, it is not inconceivable that water dealers could be installing alternative-energy-powered, electrically regenerated ion exchange systems for their customers within the next 10 years. The concept of a net-zero environmental impact softener now becomes far more realistic than ever before.
One of the most promising CDI offerings that I’ve seen to date is Anil Jha’s Hydronovation system that leverages CDI along with a retention/mixing tank to make the system more affordable.
WQA Aquatech is a venue that certainly emphasizes the need for environmentally responsible water quality management. When you attend the annual show in Las Vegas, Nevada this year, look carefully at the innovative technologies that can sustain your business and take the opportunity to learn from those who are already deploying them.
Glossary:
Electrolysis - Using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction.
Mesoporous carbon – Carbon containing pores with diameters between 2 and 50 nm.
Chillin’ with Old Man Winter…
Old-man winter is nipping here in the northern hemisphere. Snow is already falling in some areas and a natural question extends to winter and its effect on water softeners and filtration systems. Water temperature has a significant effect on the capacity and functionality of many water treatment processes. A smart dealer must be aware of the influence of ambient temperature and water temperature on the effectiveness and longevity of the water quality improvement systems that they sell, install and maintain. As a covalently bonded hydrogen compound, water behaves quite uniquely when temperatures drop. As it cools, water’s density tends to increase (like most other compounds) until it reaches the anomalous expansion rangeof 4-0°C (39.2-32°F) at which point its density decreases. This unique property gives ice its ability to float which prevents lakes from freezing solid, and of course allows for water to burst plumbing pipes and potentially wreak havoc on water treatment devices.
Membrane separators
Since water increases in density before reaching the anomalous expansion range, membrane flux in reverse osmosis, nanofiltration and ultrafiltration systems will decrease significantly as water temperatures drop. Smart dealers will make the appropriate adjustments and compensations as recommended by the equipment manufacturer to deliver the maximum amount of permeate without causing premature equipment failure.
Backwashing filters
Increasing water density means that less backwash flow rate is required to lift the media in a tank. Consult with your OEM about designing equipment with sufficient freeboard and appropriately sized backwash flow controls to ensure that no media is lost from the system.
Water softeners
While resin manufacturers are usually concerned with excessively high water temperatures on ion exchange resin, cold water temperatures also present their own share of issues. Cold water decreases resin kinetics and increases salt dissolution times. Slow kinetics cause a dramatic decrease in ‘effective’ system capacities, which usually causes customers to end up with hard water bleed-through unless the dealer makes appropriate programming compensations. Naturally, systems with resin status sensors will automatically compensate for this phenomenon. Most dealers will derate the system by as much as 30 percent if it will be exposed to cold influent water in the range of 1.6 to 7.2 °C (35 to 45°F).
Winterization procedure for water softeners
There are many opinions on how to winterize water softeners. Some dealers believe that since most softeners installed in cold climates are located in basements that they require no winterization. I believed that until I witnessed ambient temperatures in Montana basements hovering at -10F (-23°C) during January in unoccupied vacation homes. These low ambient temperatures cause fiberglass resin tank to split as if they were opened by a zipper. Not a healthy situation when things finally thaw out in spring! Winterization is normally only performed when the home/business will be unoccupied and marginally heated during winter.
A simple and generally safe and effective single tank water softener winterization procedure is as follows:
- Initiate a manual regeneration cycle.
- Advance manually to the brine/rinse ion exchange cycle.
- Induce a saturated brine solution into the softener along with resin cleaner and disinfectant into the mineral tank. (five gallons of brine per cubic foot of resin)
- Bypass the system and terminate the regeneration cycle.
If the building will be unheated and piping blown-out or drained down, the following additional steps should be performed instead of bypassing the system:
- Inject compressed air through the brine port at a maximum of 20 psi until all brine has been purged from the resin tank down the drain.
- Advance through each remaining regeneration step to allow water to drain from the control head.
- Leave the system in service (Do not bypass).
- Disconnect and remove the float from the brine tank; drain and store in a safe place.
- Drain down or blow down the home as per normal winterization procedures.
Some dealers perform winterization by inducing antifreeze into the mineral tank with a pump. When using antifreeze, be careful to use only propylene glycol (food-grade) antifreeze. Ethylene glycol antifreeze is highly toxic and should never be used for winterization. Concentrated polyethylene glycol is acts an effective anti-bacterial in most cases.
Springtime startup procedures should include a rigid disinfection and rinsing protocol to provide for the health and safety of the establishment and its occupants. As with all things, be sensible, thoughtful and methodical in your approach to winter. Consult with your OEM and dealer network to ensure that you are employing the best industry practices to give your customers the very best water year-round.
Density of Liquid Water
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Values below 0 °C refer to super-cooled water.
The Never-ending Quest for Good Water
Dealer Dynamics: The Never-ending Quest for Good Water
Greg Reyneke, CWS-VI
Living in America is wonderful. Our massive consumer-centric culture, access to cheap technology, copious quantities of cheap food and a seemingly unlimited supply of potable water are taken for granted here and in many other first-world nations. As with the entire world though, there are haves and have-nots; when it comes to access to clean, delicious, life-sustaining water, there are many people who certainly ‘“have-not’”.
When we talk about a lack of clean water, first world arrogance casts its eyes to visions of starving, dehydrated people in exotic locales, but it is really much simpler than that. Our entire human race runs on water. Every function of our bodies and even our civilization relies on water of varying quality. Without potable water, humankind would certainly cease to exist!
Looking at 2011 so far, it has not been a very good year for water quality in the developed world; natural and man-made disasters have caused significant contamination to surface and groundwater supplies. Earthquakes and tsunami activity have wreaked havoc; northern Japan is still discovering how much damage has been done. Shale fracking procedures have possibly contaminated groundwater and even permanently changed the hydrodynamics of certain aquifers. Flooding in the American northeast has liquidized the last hundred years of ground-level soil toxicity, creating a groundwater contamination nightmare whose consequences will certainly haunt us for many years to come.
That (usually) clean glass of water that comes from your tap is a distinct luxury compared to many other parts of the world. Our municipalities and privately owned water utilities work extremely hard with the limited funds that they have at their disposal to provide us with working utility-grade water that meets minimum legislated safety standards. It is our responsibility to help our clients bring their water quality to a level that meets their own individual sense of quality, taste, feel and cleanliness. We have many tools at our disposal: sediment filters, iron filters, pH neutralizers, softeners, conditioners, ultrafilters, nanofilters, distillers, RO purifiers, and a host of other technological wonders unheard of and even unobtainable in many parts of the world.
In some areas of this planet, the lady of the house will walk over a mile in oppressive heat with a 20-liter (5.28-gallon) container with her infant on her back, to the nearest pumped safe water from a community supply. Once full, she will hoist that heavy burden onto her head and walk home with a smile on her face, grateful to have clean water for her family. It is humbling indeed to think of this scenario while sipping on a glass of iced purified water that required no more effort on my part than simply raising my carcass of the couch and depressing the lever on a faucet. Oh, how much we do take for granted!
In many parts of the world, normal people are paying the price for our insatiable appetite for cheap consumer goods. Villagers in China, India, Vietnam and the Philippines increasingly have to deal with PCBs, industrial solvents, heavy metals and other toxins in their water due to negligent environmental stewardship by local industry and governments who put profits ahead of people. Other areas face the ongoing threat of poor infrastructure, where drinking water supplies get contaminated with human and animal waste through ignorance and negligence.
Without clean water, life has very little value. Growing up in South Africa I frequently passed the retaining wall at Hartebeespoort dam, where the Latin phrase Sine Aqua Agricola est Misera was chiseled into the granite for all to see. Loosely translated it means without water the farmer is sad. Without clean water all humankind is sad indeed. Our vocation and duty as water quality improvement professionals is to improve the comfort, health and safety of our clients by improving the quality and aesthetics of their water.
Many excellent NGOs, like “Water for People” (waterforpeople.org) and Clean Water Fund (cleanwaterfund.org) exist to bring good clean water to those who need it in America and around the world. When deciding your personal and corporate philanthropy this year, please consider contributing to organizations like these to help others locally and globally come closer to the levels of clean water quality that we enjoy.
Keep helping your clients get the quality of water that they deserve. Never settle for minimum standards and remember to give to those who desperately need our help.