Magnetic water treatment

Physical devices (catalytic devices) for the nonchemical treatment of water and, more specifically, devices for scale prevention that employ magnetic fields have been part of the water treatment marketplace around the world since its earliest days. These devices include electronic, catalytic, electrostatic, and magnetic water treatments. There are also various other types of more recent alternative technologies (to chemical treatments) now available in the marketplace. These are being promoted for use in treating all types of MU water, FW, and BW. 

Despite the rhetoric surrounding the subject of magnetic water treatment, some useful information can be gleaned from technical papers and supplier s literature (extracts of which are reported below), which may help the reader form an informed opinion on the benefits or otherwise of this form of pretreatment. 

Darvill, Mike (Hydrotec, Ltd. UK). Magnetic Water Treatment. W WT Journal, UK, July 1993. 

Duffy, E.A., 1977, Investigation of magnetic water treatment devices. PhD Thesis, Clemson University. 

The magnetic water treatment has similar effects as a removal of Ca and Mg from water. 

Kotsinaris, A., van Rosmalen, G.M. and Hounslow, M.J. (1999) Magnetic water treatment. Paper 228 in Industrial Crystallization (14th S5mposium, Cambridge), IChemE, Rugby. 

CSIRO, Magnetic Water Treatment, International News, Water Waste Treatment, September, 4 (1980)... 

For more than 50 years, magnetic devices and other devices have been regularly tested and compared with other water treatment methods, notably chemicals. Although irrefutable, documented evidence of their beneficial effect in industrial water systems still seems sadly lacking, they have enjoyed a profitable share of the water treatment market. 

Whether magnetic devices and related technologies really do work under any or some limited circumstances is still debatable. It is clear, however, that, in general, the chemical-based water treatment companies remain extremely skeptical, although the market has perhaps... 

The LKC eliminates many problems that are presented by the utilization of permanent magnetic or electrostatic water treatment devices of which you may have heard. ... 

The stability of iron oxide suspensions is relevant to fields as varied as the paint industry, extraction of iron from its ores, the structure of soils, hydrometallurgy and waste water treatment. The ease of homogensisation of paint, for example, is controlled by proper adjustment of the stability of the pigment suspensions. In ground waters, the settling behaviour of small iron oxide particles influences transportation of trace elements and radio-nuclides. The stability of a dispersion of magnetic particles can determine the quality of ferrofluids and magnetic tapes. 

Electro- magnetic Liquids only 1.5 (See Volume 1, Section 6.3.9) Additives in pharmaceuticals, paint, pulp and paper, water treatment using chlorine Good chemical resistance. Hygenic and intrinsically safe. Wide range. Requires some conductivity... 

It is useful to be able to compare the relative costs of a typical magnetic device system with a water treatment chemical program (scale, corrosion, and dispersion of sludges only). Although selling prices may vary considerably across the competitive market spectrum and will also tend to rise over the years, a very basic exercise, as discussed below and shown in Table 3.3, will serve to provide some comparison. 

Although the design is not normally used, Lombrana et al. (1989) demonstrated the use of a magnetically stirred cylindrical bubble column for the experimental study of agricultural reclamation of residuals from waste-water treatment plants. The magnetic stirrer provided gentle additional mixing in the bubble column, which is needed for the uniform suspension of residual material. 

The membrane developed in this work and a cottunercial activated carbon F-400 (Calgon), which is widely used in various water treatments, were used for adsorption experiments. The adsorption isotherms of phenol were measured according to the following batch adsorption method. The sealed vial was placed in a constant-temperature water bath kept at 25 T . The samples were well stirred, using a magnetic stirrer overnight (Sakoda et al, 1991). 

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