Magnetic water treatment
Encyclopedia
Magnetic Water treatment usually by the application of a changing Magnetic flux
is a proposed method of water softening
The flux change may be deliberately caused by an electromagnet
or the result of water flowing near a permanent magnet, usually in a pipe surrounded by the magnetic water treatment transducer
device.
Magnetic water treatment (also known as Anti-scale Magnetic Treatment or AMT) is a proposed method of reducing the effects of hard water
, as an alternative to water softening
. Vendors of magnetic water treatment devices have claimed that powerful magnet
ic fields can affect the structure of water molecules or the properties of solutes passing through the magnetic field
, thus eliminating the need for chemical softening agents. Only the effective hardness is claimed to be altered; no solutes (such as calcium or magnesium) are removed from the water by the process.
Most scientific studies do not support these claims and suggest that magnetic water treatment may be ineffective.
Certainly many, perhaps most claims for small domestic apparatus may be pseudoscientific
because the magnetic field, if it works at all, would have to be very powerful, and this high flux is not easily achieved in a small space.
However there is some evidence of some effect, for example K. W. Busch, M.A. Busch~Desalination 109 (1997) agree that many reports are "...generally negative [quoted:J.E. Alleman(1985)].Fluid flow in .. systems... [ẁhich are].. slow and intermittent. Other types of once-through testing should also produce negative results [quoted: G.J.C. Limpert and J.L. Raber (1985)]. On the other hand, it should not be surprising that two of the most recent field successes reported for these devices [quoted: J.F. Grutsch and J.W. McClintock (1982) & R.J. Szostak and D.A. Toy(1985)] involved constantly recirculating cooling towers where sufficient linear fluid flow velocity was maintained continually, the solution was repeatedly recirculated through the [Magnetic Treatment Device] MTV, and the solution conductivity was relatively high and increased with increasing cycles of concentration.".
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 proponents propose that formation of the softer polymorph aragonite
over the more common calcite
is favored in the presence of a magnetic field; 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 more soluble calcium aragonite over calcium carbonate, and the resulting removal of calcium carbonate deposits from a steel substrate. and . Furthermore, in their 2010 publication, Liu et all 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.
Some devices are passive magnets attached to a water pipe, but there is limited scientific explanation as to why these should have any effect. Other devices send a pulsating and reversing electric current through one or more coils located in close proximity around the water pipe, creating pulsating and reversing electro-magnetic fields in the water. Where two or more coils are used, the effect of this is said to be to cause the limescale particles to collide into each other and hence to change their crystal structure (i.e. from calcium carbonate to more soluble calcium aragonite). This effect would appear to depend on the particular properties of the water (e.g. the presence of other elements such as iron and magnesium) and, if it does occur, may be due to other, as yet unidentified, interactions in the water. There are mixed reports from consumers as to the effectiveness of these devices.
to support their claims, but omit quantitative detail and well-controlled studies. Advertisements and promotions generally omit such system variables as corrosion coupon 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.. Nevertheless, some studies do suggest that it may be effective under some conditions to reduce buildup of calcium carbonate deposits.
formation on the teeth when exposed to magnetically treated water. The same study reported that reduction in plaque and gingival index was not statistically significant.
If magnetic water treatment were to work, a health benefit, by comparison to conventional water softening treatment using sodium-based ion replacement, would be the avoidance of increasing dietary sodium intake.
Magnetic flux
Magnetic flux , is a measure of the amount of magnetic B field passing through a given surface . The SI unit of magnetic flux is the weber...
is a proposed method of water softening
Water softening
Water softening is the reduction of the concentration of calcium, magnesium, and certain other metal cations in hard water. These "hardness ions" can cause a variety of undesired effects including interfering with the action of soaps, the build up of limescale, which can foul plumbing, and...
The flux change may be deliberately caused by an electromagnet
Electromagnet
An electromagnet is a type of magnet in which the magnetic field is produced by the flow of electric current. The magnetic field disappears when the current is turned off...
or the result of water flowing near a permanent magnet, usually in a pipe surrounded by the magnetic water treatment transducer
Transducer
A transducer is a device that converts one type of energy to another. Energy types include electrical, mechanical, electromagnetic , chemical, acoustic or thermal energy. While the term transducer commonly implies the use of a sensor/detector, any device which converts energy can be considered a...
device.
Magnetic water treatment (also known as Anti-scale Magnetic Treatment or AMT) is a proposed method of reducing the effects of hard water
Hard water
Hard water is water that has high mineral content . Hard water has high concentrations of Ca2+ and Mg2+ ions. Hard water is generally not harmful to one's health but can pose serious problems in industrial settings, where water hardness is monitored to avoid costly breakdowns in boilers, cooling...
, as an alternative to water softening
Water softening
Water softening is the reduction of the concentration of calcium, magnesium, and certain other metal cations in hard water. These "hardness ions" can cause a variety of undesired effects including interfering with the action of soaps, the build up of limescale, which can foul plumbing, and...
. Vendors of magnetic water treatment devices have claimed that powerful magnet
Magnet
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, and attracts or repels other magnets.A permanent magnet is an object...
ic fields can affect the structure of water molecules or the properties of solutes passing through the magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
, thus eliminating the need for chemical softening agents. Only the effective hardness is claimed to be altered; no solutes (such as calcium or magnesium) are removed from the water by the process.
Most scientific studies do not support these claims and suggest that magnetic water treatment may be ineffective.
Certainly many, perhaps most claims for small domestic apparatus may be pseudoscientific
Pseudoscience
Pseudoscience is a claim, belief, or practice which is presented as scientific, but which does not adhere to a valid scientific method, lacks supporting evidence or plausibility, cannot be reliably tested, or otherwise lacks scientific status...
because the magnetic field, if it works at all, would have to be very powerful, and this high flux is not easily achieved in a small space.
However there is some evidence of some effect, for example K. W. Busch, M.A. Busch~Desalination 109 (1997) agree that many reports are "...generally negative [quoted:J.E. Alleman(1985)].Fluid flow in .. systems... [ẁhich are].. slow and intermittent. Other types of once-through testing should also produce negative results [quoted: G.J.C. Limpert and J.L. Raber (1985)]. On the other hand, it should not be surprising that two of the most recent field successes reported for these devices [quoted: J.F. Grutsch and J.W. McClintock (1982) & R.J. Szostak and D.A. Toy(1985)] involved constantly recirculating cooling towers where sufficient linear fluid flow velocity was maintained continually, the solution was repeatedly recirculated through the [Magnetic Treatment Device] MTV, and the solution conductivity was relatively high and increased with increasing cycles of concentration.".
Mechanism
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 KronenbergKlaus Kronenberg
Klaus J. Kronenberg was a German-born and -educated physicist who specialised in magnetism. After immigrating to the United States, Kronenberg worked from 1953 to 1963 at the Indiana General Corporation, Magnetics Division, in Valparaiso, Indiana, then as an associate professor at California State...
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
Brunel University
Brunel University is a public research university located in Uxbridge, London, United Kingdom. The university is named after the Victorian engineer Isambard Kingdom Brunel....
, proposed that the crucial step is the interruption of agglomeration of particles carrying a surface charge
Surface charge
Surface charge is the electric charge present at an interface. There are many different processes which can lead to a surface being charged, including adsorption of ions, protonation/deprotonation, and the application of an external electric field...
after dissolved contaminants have nucleated as a colloidal suspension. Simon Parsons of the School of Water Sciences at Cranfield University
Cranfield University
Cranfield University is a British postgraduate university based on two campuses, with a research-oriented focus. The main campus is at Cranfield, Bedfordshire and the second is the Defence Academy of the United Kingdom based at Shrivenham, Oxfordshire. The main campus is unique in the United...
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 proponents propose that formation of the softer polymorph aragonite
Aragonite
Aragonite is a carbonate mineral, one of the two common, naturally occurring, crystal forms of calcium carbonate, CaCO3...
over the more common calcite
Calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...
is favored in the presence of a magnetic field; an internal study in 1996 at Lawrence Livermore National Laboratory
Lawrence Livermore National Laboratory
The Lawrence Livermore National Laboratory , just outside Livermore, California, is a Federally Funded Research and Development Center founded by the University of California in 1952...
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 more soluble calcium aragonite over calcium carbonate, and the resulting removal of calcium carbonate deposits from a steel substrate. and . Furthermore, in their 2010 publication, Liu et all 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.
Some devices are passive magnets attached to a water pipe, but there is limited scientific explanation as to why these should have any effect. Other devices send a pulsating and reversing electric current through one or more coils located in close proximity around the water pipe, creating pulsating and reversing electro-magnetic fields in the water. Where two or more coils are used, the effect of this is said to be to cause the limescale particles to collide into each other and hence to change their crystal structure (i.e. from calcium carbonate to more soluble calcium aragonite). This effect would appear to depend on the particular properties of the water (e.g. the presence of other elements such as iron and magnesium) and, if it does occur, may be due to other, as yet unidentified, interactions in the water. There are mixed reports from consumers as to the effectiveness of these devices.
Studies of effectiveness
Scientific and engineering studies generally refute the effectiveness of the method, finding no differences not attributable to other causes between systems with and without a magnetic water treatment device, and no theoretical basis to expect that there might be. Vendors frequently use pictures and testimonialsAnecdotal evidence
The expression anecdotal evidence refers to evidence from anecdotes. Because of the small sample, there is a larger chance that it may be true but unreliable due to cherry-picked or otherwise unrepresentative of typical cases....
to support their claims, but omit quantitative detail and well-controlled studies. Advertisements and promotions generally omit such system variables as corrosion coupon 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.. Nevertheless, some studies do suggest that it may be effective under some conditions to reduce buildup of calcium carbonate deposits.
Other claimed effects of magnetically treated water
One study has claimed statistically significant reduction in calculusCalculus (dental)
In dentistry, calculus or tartar is a form of hardened dental plaque. It is caused by the continual accumulation of minerals from saliva on plaque on the teeth...
formation on the teeth when exposed to magnetically treated water. The same study reported that reduction in plaque and gingival index was not statistically significant.
If magnetic water treatment were to work, a health benefit, by comparison to conventional water softening treatment using sodium-based ion replacement, would be the avoidance of increasing dietary sodium intake.