Magnetic water treatment
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Magnetic water treatment is a proposed method of reducing the effects of hard water, as an alternative to water softening.[1] Vendors of water treatment devices have claimed that powerful magnetic 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.[2] Only the effective hardness is claimed to be altered; no solutes (such as calcium or magnesium) are removed from the water by the process.[1][2] Scientific studies do not support these claims and suggest magnetic water treatment may be ineffective and pseudoscientific.
Contents
* 1 Hypothesis of operation
* 2 Studies of effectiveness
* 3 Other claimed effects of magnetically treated water
* 4 See also
* 5 References
Hypothesis of operation
Magnetic water treatment proponent Klaus Kronenberg hypothesised[3] that the shapes of molecules in hard water are sufficiently modified by strong magnetic fields to precipitate dissolved calcium (also known as lime) as spherical or round crystals in suspension rather than as the familiar sheets or platelets of hard crystals known as limescale.
John Donaldson, professor of chemistry at Brunel University, has proposed that the magnetic field interacts with charged species in fluids such as ion pairs, free radicals and highly surface-charged particles in dispersions and emulsions. His hypothesis is that this interaction stabilises certain clusters before they can accumulate as crystals, and that this delays the rate of crystallisation and the formation of scale. His laboratory has shown that calcium carbonate solution takes twice as long to form limescale in a magnetic field.[4]
Simon Parsons of the School of Water Sciences at Cranfield University supports the theory that the magnetic treatment is an interfacial effect: "It is affecting the interface of the particles rather than how they nucleate." Parsons says that results indicate that magnetic treatment increases the coagulating tendency of the suspension by reducing surface charge. This means that larger particles form in solution and don't stick to the wall, so scale doesn't build up.[4]
Studies of effectiveness
Vendors frequently use pictures and testimonials to support their claims, but scientific studies are few, and generally refute the effectiveness of the method.[2][5] Consumer Reports carried out a two-year experiment with two water heaters; the end result showed no evidence of any benefit.[6]
A 2003 study published in Water SA reports suppression of scale formation and calcium precipitation in hot water tanks with permanent magnets clamped to the feed line. The reported reduction compared with a control tank was an average of 34% (17%—70% study extrema).[7]
Other claimed effects of magnetically treated water
One study has reported a statistically significant reduction in calculus formation on the teeth when exposed to magnetically treated water.[8][9] The same study reported that reduction in plaque and gingival index was not statistically significant.
