Since potable water is essential for life, efforts to improve and preserve its quality are of paramount importance. However, both surface and groundwater are contaminated in much of the world and unfit for drinking. This critical problem will only get worse as the world’s population increases from its current level of 7.7 billion to 9.7 billion in 2050.[1]
The World Bank estimated the cost of providing worldwide clean water as $150 billion.[2] Hard water is a global, natural problem that either results in billions of dollars of damages due to the deposit of scales in water systems and the subsequent economic waste, or if treated with conventional water softening techniques pose danger on both human health and the environment.[3,4]
This urgent need for ‘greener' and economically feasible means to address the issue of water hardness has stimulated extensive scientific research and development in the last decade. Science has brought the EAF (electronic anti-fouing) Technology from industrial fields to maturity for domestic application: An environment and human friendly treatment that dramatically prevents and reduces scale deposits.[4]
The purpose of this initiative is to capitalize on these scientific efforts to demonstrate EAF as a potent, proven alternative to avoid or minimize the use of conventional water softeners and descaling systems – for the sake of our planet.
1. United Nations Department of Economic and Social Affairs. World Population Prospects 2019: Highlights. (2019).
2. Hares, S. The cost of clean water: $150 billion a year, says World Bank. Thomson Reuters Foundation. (2017) >>
3. C.B. Panchal, J.G. Knudsen, Mitigation of water fouling: technology status andchallenges, Adv. Heat Transfer, 1998 4. H. Muller-Steinhagen (Ed.), Handbook of Heat Exchanger Fouling-Mitigation andCleaning Technologies, Publico Publications, Germany, 2000.
5. Georgiou, Dimitri & Bendos, Dimitris & Kalis, Manolis & Koutis, Charilaos. Removal and/or prevention of limescale in plumbing tubes by a radio-frequency alternating electric field inductance device. Journal of Water Process Engineering, 2018, >>
Hard water is a global phenomenon, curse and blessing: On one hand scale deposits cause billions of dollars of economic damage by blocking water piping systems and deterioration of heat transfer equipment performance due to the much lower thermal conductivity of scale compared to that of pipe materials. On the other hand, hard water has a high concentration in vital minerals such as Magnesium and Calcium, that are essential for human health and should not be eliminated.
Water hardness is a natural phenomenon of global scope caused by ground water. Water hardness can be measured and classified in different unit measures, all based on the concentration of minerals.
Water Hardness matters
In contrast to “soft water”, “hard water” is water that contains a high concentration of minerals, usually calcium (CaCO3) or magnesium (MgCO3) carbonates, chlorides (CaCl2 or MgCl) or sulphates (CaSO4 or MgSO4). The hardness of water depends on its source: Hard groundwater is formed when water percolates through porous rocks, usually limestone (which introduces calcium into the water) and dolomite (which introduces magnesium).[1]
In the US alone, 41% of America’s population regularly depends upon groundwater for its drinking water supply[2] whilst the UNESCO estimates that globally, more than 2.5 billion people depend solely on groundwater.[3] In addition to domestic needs, groundwater is also key for irrigated agriculture and indirectly for food security, as well as for industrial purposes.
Given the severe economic, environmental and health consequences of hard or artificially “softened” water, the topic is globally highly relevant.
Determination of water hardness
The hardness of water can be quantified as the sum of the molar concentrations of calcium and magnesium in mol/L or mmol/L. Other more commonly used units for measuring water hardness are dGH (degree of general hardness), dH (German degrees), ppm (parts per million), gpg (grains per gallon) or fH (French degrees).
The United States Geological Survey Office’s classification[4] of water hardness can be generalized and converted to other units:
Hardness classification and unit conversions
Classification | mg-CACO3/L | mmol/L | dGH | fH |
---|---|---|---|---|
Soft | 0–60 | 0–0.60 | 0–3.37 | 0-6 |
Moderately hard | 61–120 | 0.61–1.20 | 3.38–6.74 | 6.1–12.0 |
Hard | 121–180 | 1.21–1.80 | 6.75–10.11 | 12.1–18.0 |
Very hard | ≥ 181 | ≥ 1.81 | ≥ 10.12 | ≥ 18.1 |
Information regarding the local hardness of water is usually provided by national or regional water utilities.
1. Lime treatment and its effects on the chemistry and biota of hardwater eutrophic lakes; Freshwater Biology, 2001
2. National Groundwater Association; Groundwater Use in the United States of America, 2020, >>
3. UNESCO; World’s Groundwater Resources Are Suffering from Poor Governance, 2012.
4. U.S. Geological Survey Office of Water Quality; USGS Water-Quality Information: Water Hardness and Alkalinity, 2020, >>
Hard water produces devastating effects to both households and industries. Its scaling effects include pipe blockages, damage to desalination membranes and reduction in the efficiency of heat exchangers, such as boilers – fouling problems are widespread, causing billions of dollars of cleaning and maintenance costs, as well as high energy waste due to heating inefficiencies.
Scale deposits in water systems
Calcium carbonate is an inversely soluble salt,[1] i.e., its solubility decreases with increasing temperature. Scaling occurs when the concentration of a sparingly soluble salt exceeds its solubility in water. This usually results from changes in pH, temperature, outgassing or pressure that impact the solubility of the salts[2] and a concentration or evaporation process. For instance, when the water temperature increases, the solubility of CaCO3 decreases, which results in precipitation onto heated surfaces.
The resulting scale deposits in water systems of industrial plants, domestic facilities and appliances cause significant technical problems and economic losses by blocking the flow of water in pipes. [3][4]
The cost of cleaning and maintaining industrial production equipment alone due to scale is billions of dollars every year – with domestic damages estimated to be even higher. [5][6]
Heating inefficiencies: High energy waste and cost
Due to the decreasing solubility of Calcium with the increase in temperature, heated surfaces in industrial plants, domestic appliances and water systems are particularly affected: Calcium carbonate has a thermal conductivity of 2.9W/mK, which is less than 1% of that for metal copper (401W/mK). For example only a 1mm layer of Calcium carbonate on a heating surface can double the energy requirement.[7] Similarly a 5mm layer of Calcium carbonate can increase energy consumption up to 70%.[8] Thus scale depositions cause energy waste and significant economic losses. The problem is widespread, eg Steinhagen et al. [9] showed in a New Zealand survey that 90% of heat exchangers had fouling problems.
Wastefulness and the poor quality of detergents in soft water
Due to reduced chemical reaction, hard water requires a considerably larger amount of soap to produce a lather.[10] Cleaning agents that are used with hard water become less effective and are unable to completely remove dirt and grime.[11] This results in nuisance problems, such as clothes that become dingy and gray with prolonged washing and feel harsh or scratchy. Glassware may develop spots as it dries. Films may build up on shower doors or curtains, walls and tubs, and hair washed in hard water may look dull and not feel clean. The decreased effectiveness of nearly any cleaning task causes a large amount of waste of soap and cleaners, causing high costs and polluting the environment.
Quantifying the severe damage of hard water
Scaling problems caused by hard water lead to significantly decreased operating efficiency, shortened equipment life, higher maintenance cost and increased energy consumption.[12][13] The economic implication of scale formation to industries like the USA, UK and Japan are approximately $10 billion, $900 million and $3 billion respectively in a single year.[14] A cost estimate of fouling for the entire industrialized world is presented in Table 1.
Country | Cost due to fouling |
---|---|
UK | 700 – 930 |
USA | 8 000 – 10 000 |
Japan | 3 062 |
Total industrialized world | 26 850 |
1. Tijing, L.D.; Pak, B.C.; Lee, D.H.; Cho, Y.I.; Heat-treated titanium balls for the mitigation of mineral fouling in heat exchangers. Exp. Heat Transf. 2008.
2. Alabi, A., Chiesa, M., Garlisi, C. & Palmisano, G.; Advances in anti-scale magnetic water treatment. Environ. Sci.: Water Res, 2015.
3. Gabrielli, C., Jaouhari, R., Maurin, G. & Keddam, M.; Magnetic water treatment for scale prevention. Water Res., 2001.
4. Lin, L., Xu, X., Papelis, C. & Xu, P. Innovative use of drinking water treatment solids for heavy metals removal from desalination concentrate: Synergistic effect of salts and natural organic matter; Chem. Eng., 2017.
5. Tijing, L.D.; Lee, D.H.; Kim, D.W.; Cho, Y.I.; Kim, C.S: Effect of high-frequency electric fields on calcium carbonate scaling; Desalination, 2011.
6. Xing, X.: Research on the electromagnetic anti-fouling technology for heat transfer enhancement; Appl. Therm. Eng.; 2008.
7. Tijing, L.D.; Lee, D.H.; Kim, D.W.; Cho, Y.I.; Kim, C.S: Effect of high-frequency electric fields on calciumcarbonate scaling. Desalination, 2011.
8. Chen, C. & Zhou, K.: Magnetic treatment water corrosion. Magn. Energy Appl. Technol. (2), 7–11.
9. R. Steinhagen, H. Muller-Steinhagen, K. Maani, Problems and costs due to heatexchanger fouling in New Zealand industries, Heat Transfer Eng. 14 (1) (1993)19–30.
10. World Health Organization (WHO), Hardness in Drinking-water, 2011
11. S. Skipton, B. Dvorak; Drinking water treatment: water softening (ion exchange), 2015
12. X. Xiaokai; Research on the electromagnetic anti-fouling technology for heat transfer enhancement, Appl. Therm. Eng. 28 (2008) 889–894
13. S.N. Kazi, G.G. Duffy, X.D. Chen; Mineral scale formation and mitigation on metals and a polymeric heat exchanger surface, Appl. Therm. Eng, 2010.
14. MacAdam and S. A. Parsons, Rev. Environ. Sci. Bio/Technol., 2004, 3, 159–169
Whilst hard water causes billions of dollars in damages, the World Health Organization (WHO) concludes from a range of peer reviewed scientific studies: Hard water that contains high concentrations of calcium and magnesium, possesses several health benefits. However an inadequate intake of either essential nutrient can impair health.[1] During the last decade, many epidemiologists found an inverse relationship between water hardness and cardiovascular mortality. This positive health effect is highly apparent in cooked foods, which heavily affects the levels of these minerals.
Calcium: Important structural component of the human body
Over 99% of the total calcium in the body is found in bones and teeth, where it functions as a key structural element. The remaining calcium in the body functions in metabolism, serving as a signal for vital physiological processes, including vascular contraction, blood clotting, muscle contraction and nerve transmission. Individuals with poor calcium intake may become prone to several life-threatening conditions, such as increased risks of osteoporosis, nephrolithiasis (kidney stones), colorectal cancer, hypertension and stroke, coronary artery disease, insulin resistance and obesity.[2]
Magnesium: An essential cofactor in more than 300 enzyme systems
Magnesium is a vital cofactor in more than 300 enzyme systems that regulate diverse biochemical reactions in the body, including protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation. Low intakes of magnesium induce changes in biochemical pathways that can increase the risk of illnesses, including hypertension and cardiovascular disease, type 2 diabetes, osteoporosis, and migraine headaches.[3]
Studies of Calcium and Magnesium in Drinking Water
More than 80 observational epidemiological studies that related water hardness and cardiovascular disease risks were analyzed by the WHO in 2009. Most of these studies were published in peer reviewed English-language scientific journals and found an inverse (protective) association between cardiovascular disease mortality and increased water hardness. [4]
Besides lower risk of cardiovascular disease mortality, there is also evidence that calcium and magnesium in drinking water can help protect against gastric, colon, rectal, and pancreatic cancers and that magnesium can help protect against esophageal and ovarian cancer.[5]
In a 2009 paper published by the WHO together with scientific experts on public health significance of calcium and magnesium in drinking-water by the WHO, the authors summarized the literature and found support for a link between a lack of magnesium and cardiovascular mortality. They also concluded that not removing magnesium from drinking water may be beneficial.[6]
Can water be too hard and cause health hazards?
According to the WHO, it is fairly difficult for humans with healthy kidneys to experience hypercalcemia (too much calcium). The National Institute of Health (NIH) explains that too much magnesium from food or drinking does not pose a health risk in healthy individuals because the kidneys eliminate excess amounts in the urine.[7] However scale deposits in pipes can cause increased growth of bacteria in drinking water
1. World Health Organization (WHO) 2011, Hardness in Drinking-water, >>
2. World Health Organization (WHO) 2009, Calcium and Magnesium in Drinking-water: Public health significance, >>
3. National Institutes of Health NIH, Office of dietary supplements: Magnesium, >>
4. World Health Organization (WHO) 2009, Calcium and Magnesium in Drinking-water: Public health significance, >>
5. International Journal of Preventive Medicine 2013 Aug;Potential Health Impacts of Hard Water 4(8): 866–875. >>
6. World Health Organization (WHO) 2009, Calcium and Magnesium in Drinking-water: Public health significance, >>
7. National Institutes of Health NIH, Office of dietary supplements: Magnesium, >>
8. K.C. Makris, S.S. Andra, G. Botsaris, Pipe scales and biofilms in drinking-waterdistribution systems: undermining finished water quality, Crit. Rev. Environ. Sci.Technol., 2014
9. A.Mahapatra,N.Padhi,D.Mahapatra,M.B.D.Sahoo,S.Jena,D.Dash,N.Chayani,Study of biofilm in bacteria from water pipelines, J. Clin. Diagn. Res., 2015
The most commonly used method of controlling crystallization fouling is the addition of chemical inhibitors to potentially scaling waters[1]. Whilst being effective in removing minerals in hard water (“water softening”), chemical and ion-exchange methods generally have disadvantages, such as high cost and being harmful to the environment and human health.[2] [3] [4]
Water softeners with ion exchange technology replace natural minerals (eg Calcium and Magnesium) with sodium/salt. This chemical alteration of the water is invasive and requires a section of pipe to be removed and replaced with the device, running water through a side-stream. The consumable chemicals are expensive as well as the regular professional maintenance that is often prescribed by law.
Ion exchange process
Most water softeners are ion exchange devices: Ion exchange involves removing the hardness ions calcium and magnesium and replacing them with non-hardness ions, typically sodium supplied by dissolved sodium chloride salt, or brine. The softener device contains a microporous exchange resin, usually sulfonated polystyrene beads that are supersaturated with sodium to cover the bead surfaces. As water passes through this resin bed, calcium and magnesium ions attach to the resin beads, and the loosely held sodium is released from the resin to the water. The exchange reaction can be written as: 2 RNa + Ca++ R2Ca + 2 Na+ After a large quantity of hard water has been softened, the beads become saturated with calcium and magnesium ions. When this occurs, the exchange resin must be regenerated, or recharged. To regenerate, the ion exchange resin is flushed with a salt brine solution. The sodium ions in the salt brine solution are exchanged with the calcium and magnesium ions on the resin, and excess calcium and magnesium are flushed out with the wastewater.
High maintenance and operating costs
The amount of salt used for softening depends on the daily water usage, softener capacity and water hardness. Potassium chloride can be used as a regenerant instead of sodium chloride in certain circumstances. However, potassium chloride costs more than salt. In addition to the cost of the salt, the ion exchange resin required to remove ions from wastewater on a large scale can be highly expensive. Along with the high operating cost, the brine tank requires periodic checking and cleaning by a specialist, resulting in high maintenance costs.[5]
Furthermore, softened water is more corrosive than hard water and can cause damage to plumbing and fixtures, as well as the leaching of heavy metals, such as cadmium, copper, lead, and zinc, into drinking water.[6]
Traditional water softeners pollute the environment by discharging high amounts of sodium in water as well as wasting water with every regeneration process.
Water pollution and waste
It is widely known that traditional salt-based water-softening systems are not environmentally friendly:
(1) The softened water has an artificially high concentration of sodium/chlorine that is discharged with other wastewater and contributes to the salinity problem in the municipal sewage-treatment plants. In general, higher salinity in the wastewater increases the treatment costs and reduces the potential for reuse of treated wastewater for irrigation and industrial purposes. The chlorine released can persist in the water for as long as 40-70 years.[7] The salinity from water softeners has caused such enormous problems that farmers in California’s San Joaquin Valley had to take land out of production.[8]
(2) The softener must be kept regenerated to avoid hard water flowing into pipes and appliances. Regeneration places an additional load on a septic system. Approximately 50 gallons of water is used to regenerate a water softener, resulting in a significant amount of liquid waste.[9]
First legal bans to protect the environment
Since softened water is not recommended for plants, lawns or gardens due to its sodium content[10], it obviously should also not be released into the nature but treated for reuse, worsening the global wastewater management problem[11]: The only way to deal with the excess salt is to build an expensive wastewater treatment plant that uses reverse osmosis and is expensive to build and operate. The World Bank estimated the cost of providing worldwide clean water as USD 150 billion[12]. A severe problem that is only going to get worse, given that surface and groundwater are contaminated in much of the world and unfit for drinking, with the world’s population increasing from its current level of 7 Billion to 9.7 billion in 2050.[13]
Despite the big business of water softening (e.g., $500-million annually in California alone) and a strong lobby[14], regulators were forced to act in order to meet toughening environmental standards: As one of the first states, in January 2014, the Californian governing board approved rules banning the new installation of water softeners that use sodium, or potassium and discharge the salt solution into sewer lines. As of August 2014, salt water softeners have been banned in 25 California communities. Texas, Massachusetts, Connecticut, Michigan and New Jersey are among the many other localities that have enacted regulations on the discharge of water from water softeners.
In general more stringent environmental laws regarding chemical water softening are expected, further increasing the costs associated with storage, handling and disposal.
The problem with chemically softened drinking water is three-fold. The World Health Organization (WHO) does not consider demineralised water to be ideal drinking water due to the lack of beneficial nutrients.[15] Furthermore, domestic water softeners can increase sodium levels in drinking water, resulting in serious health risks, and the attendant chloride levels have also been found to be unhealthy. Drinking and cooking with softened water is often avoided by having an extra cold water line to the kitchen tap that bypasses the water softener.[16]
Lack of essential minerals
The ion-exchange process eliminates essential minerals like calcium and magnesium. While only 10-20% of the total daily intake of calcium and magnesium is derived from drinking water, significant differences were found in food cooked with waters of different hardness. The concentration of these minerals usually increased in foods when they were cooked with hard water, while a decrease was noted when soft water was used for cooking.[17]
The National Institutes of Health (NIH) explain that habitually low intakes of magnesium induce changes in biochemical pathways that can increase the risk of illness, such as hypertension and cardiovascular disease, type 2 diabetes, osteoporosis, and migraine headaches over time. Groups at risk are type 2 diabetes patients, older adults and patients with gastrointestinal diseases.[18]
Research by Kousa et al. and Marque et al. strongly support the conclusion that demineralised water or low mineral water – in the light of the absence or substantial lack of essential minerals in it – does not have the characteristics of safe drinking water, and therefore, its regular consumption or consumption in larger quantities should be considered as a potential health risk. [19] [20]
Excessive sodium intake
Domestic water softeners can increase sodium levels to more than 300 mg/L in drinking water. The EPA guidance level for sodium in drinking water is 20 mg/L. An excess intake of sodium due to such large volumes in the water can cause acute and long-term health effects.[21]
A large body of evidence from the American Heart Association (AHA)[22], the National Institutes of Health (NIH)[23], National Research Council (NCR)[24] and the US Department of Agriculture (USDA)[25] suggests that an excessive intake of sodium contributes to age-related increases in blood pressure and may contribute to essential hypertension.
High blood pressure is associated with an increased risk of developing coronary heart disease, stroke, congestive heart failure, renal insufficiency, and peripheral vascular diseases.
The Environmental Protection Agency (EPA) also reports that some studies suggest that sodium chloride may enhance the risk of cancer caused by other chemicals in the gastrointestinal tract.[21]
Infants and children are somewhat more susceptible than adults to the effects of acute overdoses of sodium chloride, because the kidneys of immature individuals are not as effective at controlling sodium levels as the kidneys of adults.[26]
1. MacAdam, J., Parsons, S.A. Calcium carbonate scale formation and control. Rev Environ Sci Biotechnol, 2004
2. Alimi, F. & Tlili, M. & Ben A.: Influence of magnetic field on calcium carbonate precipitation. Desalination, 2007
3. Tijing, L.D.; Lee, D.H.; Kim, D.W.; Cho, Y.I.; Kim, C.S. Effect of high-frequency electric fields on calciumcarbonate scaling. Desalination, 2011
4. Zhao, J.D.; Liu, Z.A.; Zhao, E.J. Combined effect of constant high voltage electrostatic field and variable frequency pulsed electromagnetic field on the morphology of calcium carbonate scale in circulating coolingwater systems. Water Sci. Technol., 2014
5. S.E. Manahan, Environmental Chemistry, (Fifth ed.), Lewis Publishers, 1991
6. Department of Public Health and Environment, Wathington County, >>
7. Strifling, D.. Reducing Chloride Discharges to Surface Water and Groundwater: A Menu of Options for Policymakers. Environmental Law, Marquette Law School Legal Studies Paper , 2017)
8. Soft water, hard problem: Los Angeles Times, 2009, >>
9. Waste from Water Softening Stations for Treatment Wastewater Containing Dyes, Materials Science Forum (Volume 931), 2018
10. S. Skipton, B. Dvorak, Drinking water treatment: water softening (ion exchange), 2015
11. L Valero, I Sanchez; Cost of Urban Wastewater Treatment and Ecotaxes: Evidence from Municipalities in Southern Europe, 2019
12. Hares, S. The cost of clean water: $150 billion a year, says World Bank. Thomson Reuters Foundation., 2017
13. United Nations Department of Economic and Social Affairs. World Population Prospects 2019: Highlights, 2019
14. Soft water, hard problem: Los Angeles Times, 2009, >>
15. World Health Organization (WHO), 2004: Nutrients in Drinking Water,
16. S. Skipton, B. Dvorak, Drinking water treatment: water softening (ion exchange), 2015, >>
17. Changes in the Mineral Composition of Food as a Result of Cooking in “Hard” and “Soft” Waters, Archives of Environmental Health An Intl Journal, 2013
18. National Institutes of Health NIH, Office of dietary supplements: Magnesium, >>
19. Kousa, A., Moltchanova, E., Viik-Kajander, M., Rytkonen, M., Tuomilehto, J., Tarvainen, T. and Karvonen, M.: Geochemistry of ground water and the incidence of acute myocardial infarction in Finland. J. Epidemiol. Community Health, 2004
20. Marque, S., Jacqmin-Gadda, H., Dartigues, J.F. and Commenges, D.: Cardiovascular mortality and calcium and magnesium in drinking water: An ecological study in elderly people. Eur. J. Epidemiol., 2003
21. US Environmental Protection Agency Office (EPA), Drinking Water Advisory: Consumer Acceptability Advice and Health Effects Analysis on Sodium, 2003.
22. American Heart Association (AHA). Sodium.. AHA Recommendation., 2000 >>
23. National Institutes of Health (NIH). Working group report on primary prevention of hypertension. NIH Publication No. 93-2669., 1993
24. National Research Council (NRC). Recommended dietary allowances. Washington, DC: National Academy of Sciences, National Academy Press, 1989a
25. U.S. Department of Agriculture (USDA). Nutrition and Your Health: Dietary Guidelines for Americans, 5th ed. Home and Garden Bulletin No. 232. U.S. Department of Health and Human Services, Washington, DC , 2000
26. Sax NI. 1975. Dangerous properties of industrial materials, 4th ed. New York: Van NostrandReinhold Company, p. 1101.
27. Tijing, Leonard & Kim, Hang & Lee, Dong-Hwan & Pant, Hem & Cho, Young. (2010). Physical water treatment using RF electric fields for the mitigation of CaCO3 fouling in cooling water. International Journal of Heat and Mass Transfer. 53. 1426-1437. 10.1016/j.ijheatmasstransfer.2009.12.009.
The economic and ecologic disadvantages of traditional water softeners has stimulated heavy scientific research and development activity in the last decade. The industry proven, non-chemical EAF technology becomes available for various applications. EAF devices impart electro-magnetic fields into the water, changing the way minerals in the water precipitate. Thus the minerals form suspended clusters that turn into stable crystals when temperature changes occur, avoiding hard-lime scale by producing instead a non-adherent mineral powder. On a broad research base, EAF technology proved very efficient in preventing limescale formation as well as removing existing scale whilst being environment-friendly, maintenance free and working at almost negligible energy consumption.
EAF is an acronym for Electric Anti-Fouling. The technology was first applied in the late 1980s and early 1990s in the industrial field in order to prevent plant equipment and pipeline corrosion and scaling while avoiding the high cost of chemical (using salt) prevention.
Already in 1998 the U.S. Department of Energy alerted facility managers that advances in EAF technology have led to their becoming reliable energy savers that can be used as a replacement for most traditional water-softening equipment, including applications both to cooling water treatment and boiler water treatment in once-through and circulating systems.[0] Given the increasing awareness of corporate social responsibility and sustainability, the industry-proven EAF technology has been increasingly considered a potent alternative to traditional water.
Driven by the economic and ecological benefits, such as the reduced expenditure on scale remediation, improved water conditions for human use and a reduced release of harmful substances into the environment, EAF technology has attracted increased attention by scientists and practitioners: More than 2,000 papers were published in the last decade alone, offering a wealth of research proving the effectiveness of EAF and making the originally industrial technology available for residential and commercial application.[1]
How EAF works
The term describes an application that produces a pulsing current to create time-varying magnetic fields inside a pipe. Subsequently, the time-varying magnetic field creates an induced electric field inside the pipe, a phenomenon which can be described by the following Faraday’s law[2]:
Where E is an induced electric field vector; l is a line vector along the circumferential direction; B is a magnetic field strength vector, and A is the cross sectional area of pipe.
The induced electric field that oscillates with time provides necessary molecular agitation to charged mineral ions, so that calcium and bicarbonate ions collide and precipitate. Once the dissolved ions have been converted to insoluble mineral crystals, the level of supersaturation of the water significantly decreases. Thus, new scale deposits on the heat transfer surface are reduced or prevented.[1]
In layman's terms, without the EAF treatment, the ions are converted to the aragonite form of CaCO3 particles. This dendritic shaped form, with its “sharp needles,” easily adheres to the pipe and requires acidic cleaning (images 1 and 2). Under the EAF treatment, the calcium and bicarbonate ions are converted to the loosely-connected small hexagonal-shaped calcite form of CaCO3 particles, which are powdery and fluffy, and easily removed by turbulence and natural flow of water (images 3 and 4).[3]
This is an extremely efficient way to neutralize the dissolved mineral ions and prevent them from depositing on the pipe walls. Since the mineral crystals such as calcium carbonate are insoluble, they will not be redissolved to water unless there is a significant change in pH, temperature or pressure.[4]
EAF has proven to be effective in thousands of extensive scientific studies not only in terms of scale prevention, but also removal of existing scale deposits.
Broadly examined and proven effective
More than 4,000 studies have reported that EAF is associated with anti-scaling and anti-fouling, and the quantity of publications has increased exponentially during this century, indicating that EMF has become a critical technique for scaling control but also has applications beyond industrial applications.[5]
(Source: Google Scholar)
Some of the most high-profile peer reviewed studies show that fouling for the treated water decreases up to 88% from the values for no-treatment water. [2] Other studies show an effectiveness of the EAF technology of even 95%.[6]
Lin, Jiang et al (2020) selected and evaluated 48 peer-reviewed scientific studies and conducted an in-depth analysis of the findings. In 95% of the 48 studies discussed, EAF treatment has proven effective. As many as 97.56% of the EAF treatments were effective on bulk solution reactors and pipes.[6]
Removal of existing scale deposits
Georgiou and Bendos (2018) concluded from a scientific experiment that an EAF device proved very efficient in preventing limescale formation in a plumbing tube while utilizing hard water. Furthermore, the scientists tested the same EAF device with tubes that had been in use for over 20 years in a rural area. The EAF method proved also very efficient in removing existing scale from plumbing tubes, using not only hard but also soft water. [7]
EAF technology devices are in-line and non-invasive, the installation does not require an interruption of the water flow and pipes, does not require any maintenance or chemical consumables. Thees economic advantages are accompanied by the health benefits (essential minerals in drinking water) and environmental neutrality.
Environmental
Studies have shown that EAF technology is much better for the environment. A key factor is the lack of chemicals in the water. The findings of many researchers, such as Chibowski (2003)[8] and Alimi (2006)[9], have established the positive effects of magnetic fields against lime scale deposits in water pipes and appliances. This technique also promotes an increased germination rate and plant growth (Shabrangi, 2009; Hozayn et al., 2018; Hozayn and Ahmed, 2019; Hozayn et. al., 2019)[10].
In addition, this magnetism technology can be applied in the field of agriculture by the direct application of the magnetic field to plant organs, such as seeds. Florez (2007)[11] explained that this effect could be due to the magnetization of irrigation water or the presence of paramagnetic properties in the chloroplast (Hozayn and Amira, 2010)[12]. Alternatively, Taimourya et al. (2015)[13] proved that the treatment of water by a static magnetic field resulted in positive effects on the production of cabbage (Brassica oleracea) by an increase of 30%. Elaoud et al. (2016)[14] found that magnetized water has an effect on the yield of melons in culture. Waleed et al. (2013)[15] reported that a magnetic field of 0.5 Tesla resulted in an increase in root length and weight. In conclusion, the use of the electromagnetic field could be an effective solution to improve the germination rate of lettuce and possibly other plants.
Health
The use of water that has not been chemically altered has profound implications for human health, especially since sodium has not been added in contrast to softened water. Evidence suggests that water without sodium is much healthier for people who are prone to high blood pressure. Numerous studies have shown that reductions in the dietary intake of salt correlate with decreased morbidity from stroke and kidney disease among other causes. The essential minerals that contribute to human health, such as calcium, magnesium, and sulphate, remain in the water when it is treated with EAF. Finally, there are no negative effects on hygiene with EAF, which protects and preserves the minerals in the water.
Economic
The lack of damage to industrial equipment and domestic systems greatly reduces the need for maintenance and the replacement of equipment, adding up to substantial savings. EAF devices are non-invasive and directly attached around the main incoming water pipe, allowing a very simple installation without cutting the pipes or interrupting the water flow. Utilizing EAF technology, removal and/or prevention of limescale in plumbing tubes can be achieved at almost negligible energy consumption.[7] The US Department of Energy alerted Federal energy managers about the energy saving potential of EAF technology and pointed out additional areas for savings: The first is elimination or significant reduction in the need for scale and hardness control chemicals. In a typical plant, this savings could be on the order of thousands of dollars each year when the cost of chemicals, labor and equipment is factored in. Second, periodic descaling of the heat exchange equipment is virtually eliminated. Thus process downtime, chemical usage, and labor requirements are eliminated. A third potential savings is from reductions in heat exchanger tube replacement due to failure. Failure of tubes due to scale build-up, and the resultant temperature rise across the heat exchange surface, will be eliminated or greatly reduced in proportion to the reduction in scale formation.[0]
0. The U.S. Department of Energy, Non-Chemical Technologies for Scale andHardness Control, DOE/EE-0162, 1998. >>
1. Lin, L., Jiang, W., Xu, X. et al. A critical review of the application of electromagnetic fields for scaling control in water systems: mechanisms, characterization, and operation. npj Clean Water, 2020)
2. Cho, Y I, Fan, C, and Choi, B G. Theory of electronic anti-fouling technology to control precipitation fouling in heat exchangers. United States: N. p., 1997.
3. Tijing, Leonard & Kim, Hang & Lee, Dong-Hwan & Pant, Hem & Cho, Young. (2010). Physical water treatment using RF electric fields for the mitigation of CaCO3 fouling in cooling water. International Journal of Heat and Mass Transfer. 53. 1426-1437. 10.1016/j.ijheatmasstransfer.2009.12.009.
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Absent of commercial interests, the idealistic purpose of this initiative is to demonstrate EAF technology as a potent alternative to traditional water softening methods for the sake of our environment and humanity.
If you are looking for EAF product or supplier recommendation, send us a message and we might be able to assist and connect you with someone from our network.
Scientists and researchers wishing to contribute to our initiatives are invited to send us their studies for inclustion.