Magnetic water treatment
Magnetic water treatment (also known as anti-scale magnetic treatment or AMT) is a controversial method of supposedly reducing the effects of hard water by passing it through a magnetic field, as a non-chemical alternative to water softening. Scientific studies into the efficacy the treatment have had mixed results, though several studies have produced significant effects and proposed possible mechanisms for the observed decrease in water scale. Some commentators regard the treatment as unproven and unscientific.
Magnetic treatments may be cheap and chemical-free, but there is little firm evidence of their effectiveness in domestic situations. The treatment only claims to alter the effective hardness of water; no solutes (such as calcium or magnesium) are removed from the water by the process.[clarification needed]
Vendors of magnetic water treatment devices frequently use pictures and testimonials to support their claims, but omit quantitative detail and well-controlled studies. Advertisements and promotions generally omit system variables, such as corrosion results or system mass balance analyticals, as well as measurements of post-treatment water such as concentration of hardness ions or the distribution, structure, and morphology of suspended particles.
Ultra pure water is an electrically inert chemical compound with the simple chemical formula H
2O which is not conductive of electricity nor affected by magnetism. Drinking water however may contain salts composed of cations (positively charged ions) and anions (negative ions) so that it may be electrically conductive, and so possibly susceptible to magnetic influences.
Duration of exposure and field strength, gradient, rate of change, and orientation along or perpendicular to flow are variously cited as important to the results. Magnetic water treatment proponent Klaus Kronenberg proposed that the shapes of solute lime molecules are modified by strong magnetic fields, leading them to precipitate as spherical or round crystals rather than deposit as sheets or platelets of hard crystals. John Donaldson, professor of chemistry at Brunel University, proposed that the crucial step is the interruption of agglomeration of particles carrying a surface charge after dissolved contaminants have nucleated as a colloidal suspension. Simon Parsons of the School of Water Sciences at Cranfield University proposed that the magnetic field reduces the surface charge on small particles, increasing the tendency to coagulate as large particles that stay with the flow rather than depositing as scale. Some[who?] proponents propose that formation of the polymorph aragonite over the more common calcite is favored in the presence of a magnetic field. However, an internal study in 1996 at Lawrence Livermore National Laboratory found no difference in preferred crystal structure of scale deposited in magnetic water treatment systems.
Liu et al. and Coey and Cass published research in 2010 and 2000 demonstrating that magnetic treatment causes water containing minerals to favor formation of a more soluble form of calcium carbonate (aragonite rather than calcite), and the resulting removal of calcium carbonate deposits from a steel substrate. Furthermore, in their 2010 publication, Liu et al. conclude that "The magnetic treatment of scaling waters was proved to be efficient. The efficiency obtained with this very simple magnetic device can be very much improved if the geometry is better devised." Kozic and Lipus concluded in their 2003 paper that the effects of magnetic treatment on water indeed results in reduced formation of limescale and that this effect lasts approximately 200 hours.
The effect of magnetic treatment depends on properties of the pipe. The magnititude of the effect depends on pipe conductivity and surface roughness.
There are related non-chemical devices based on a variety of physical phenomenon which have been marketed for over 50 years with similar claims of scale inhibition. Whilst some are effective, such as electrolytic devices, most do not work.
- Electrolysis: Electrolytic scale inhibitors - two metals such as copper and zinc are used
- Electrostatic: Electronic water conditioners
- Electromagnetic: fluctuating electromagnetic fields are created
- Other devices combine these different methods
Other uses of magnetic devices:
- Two studies have shown a statistically significant reduction in calculus formation on the teeth when exposed to magnetically treated water (as compared to normal water) with an oral irrigator.
- Magnetic fuel savers are similar magnetic devices marketed as saving fuel, but have no effect,as hydrocarbon fuels have no appreciable electrical resistivity and conductivity and are not susceptible to magnetic attraction.
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- Busch, KW; Busch, MA (1997). "Laboratory studies on magnetic water treatment and their relationship to a possible mechanism for scale reduction". Desalination 109 (2): 131–148. doi:10.1016/S0011-9164(97)00059-3. Retrieved 2011-10-03.
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- Smothers, KW; Curtiss, CD; Gard, BT; Strauss, RH; Hock, VF (15 June 2001). "Magnetic Water Treatment". Public Works Technical Bulletin 420-49-34. U.S. Army Corps of Engineers.
- Water Science School of the Geological Survey Office of the United States of America
- "Interview of Klaus Kronenberg, Ph. D". GMX International. Retrieved 2012-03-26.
- "A problem of scale. (water conditioning)". Entrepreneur.com. 1996-04-01. Retrieved 2009-11-07.
- Krauter, PW; Harrar, JE; Orloff, SP; Bahowick, SM (1996). "Test of a Magnetic Device for Amelioration of Scale Formation at Treatment Facility D". Internal Report (Lawrence Livermore National Laboratory). OSTI 567404. Retrieved 2009-12-11.
- Coey, JMD; Cass, S (2000). "Magnetic water treatment". Journal of Magnetism and Magnetic Materials 209: 71–74. Bibcode:2000JMMM..209...71C. doi:10.1016/S0304-8853(99)00648-4.
- Kozic, V; Lipus, LC (2003). "Magnetic water treatment for a less tenacious scale". Journal of Chemical Information and Computer Sciences 43 (6): 1815–9. doi:10.1021/ci0102719. PMID 14632427.
- Alimi, F.; Tlili, M. M.; Amor, M. B.; Maurin, G.; Gabrielli, C. (2009). "Effect of magnetic water treatment on calcium carbonate precipitation: Influence of the pipe material". Chemical Engineering and Processing: Process Intensification 48 (8): 1327. doi:10.1016/j.cep.2009.06.008.
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- Pernot B, Euvrard H, Remy F and Simon, P (1999) Influence of Zn(II) on the crystallisation of calcium carbonate application to scaling mechanisms. Journal of Water SRT-Aqua, 48(1): 16-23.
- MacAdam J PhD Thesis Cranfield University UK. Dept of Water Science and various studies
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- Johnson, KE; Sanders, JJ; Gellin, RG; Palesch, YY (1998). "The effectiveness of a magnetized water oral irrigator (Hydro Floss) on plaque, calculus and gingival health". Journal of Clinical Periodontology 25 (4): 316–21. doi:10.1111/j.1600-051X.1998.tb02447.x. PMID 9565283.
- Allen, M (25 August 2010). "Looking For A Miracle: We Test Automotive 'Fuel Savers'". Popular Mechanics. Retrieved 2012-03-26.