Test of Magnetic Treatment of Swimming Pool Water for Enhanced Chemical
Oxidation and Disinfecting
Equipment: Kulish Mark 1 Patented Monopole Magnetic Pool Technology under
the Magnetizer Brand
Joanna Elizabeth Starmer, Cranfield University
SCHOOL OF WATER SCIENCES
Supervisor: Dr. Simon A. Parsons, September 1996
ABSTRACT Magnetic water treatment is potentially of
great benefit to pool water treatment in terms of the reduction in use of
oxidizing chemicals in water treatment. Magnetic treatment has been variously
shown to stabilize solution pH, eliminate corrosion of materials and reduce
system downtime. In addition to the reduction in running costs, physical water
treatment is generally viewed as being more environmentally acceptable; reducing
the use of the strong oxidizing chemicals conventionally employed for
study determines the efficacy of a magnetic treatment device on the inactivation
of a model micro-organism (Escherichia coli), chlorine consumption concomitant
disinfecting by product formation in a swimming pool water analogue. Effects of
magnetic water treatment on physical parameters such as scale deposition;
conductivity and pH are reported, as well as the key performance determining
chlorine consumption, micro-organism inactivation rate and trihalomethane (THM)
formation. A commercially available magnetic treatment device (Magnetizer) was
Note: The original Kulish Mark 1 Monopolar (Magnetizer) system was the
most powerful magnetic water conditioning system in that it delivered the
greatest amount of mV (millivoltage) into the water. The millivoltage is the
physical working mechanism that creates the following pool water conditioning
behavior. All other systems in the marketplace at the time of the test were only
able to provide 7-50% of the power of the Mark 1 system.
Kulish’s New Mark 3 EnviroMagnetics Pool/Spa Conditioning systems are
more powerful than his former Mark1 Magnetizer Systems.
It was found that in all cases chlorine loss was more rapid in the control than
in the magnetically treated water. The bactericidal efficiency of the free
chlorine was unaffected by magnetic treatment, such that the E. coli kill rate
for a given disinfectant dose was increased by an average of 25% by this
physical conditioning. In addition, it was found that generation of THMs was
reduced by magnetic treatment at any one free chlorine level.
would like to thank the representatives of Magnetizer in the UK for the
sponsorship of this project. I would also like to thank my supervisor, Dr. Simon
Parsons, and Dr. Simon Judd for their assistance. MAGNETIC TREATMENT OF SWIMMING
POOL WATER FOR ENHANCED CHEMICAL OXIDATION AND DISINFECTING.
Many industries, including the swimming pool industry, are being
urged by regulatory bodies such as PWTAG and pressure groups to use non-chemical
treatment processes wherever possible (Gosling, 1996). PWTAG also places
pressure on operators of swimming pools in the UK to employ the "least hazardous
option" in terms of health and safety and environmental concerns (Gosling,
The contaminants of swimming pool water are mainly urine, sweat and
micro-organisms introduced by the swimmers. The major disinfectant used in
swimming pool water treatment is sodium hypochlorite which has a bactericidal
action that can be suppressed to some extent by interaction with other chemical
contaminants (Black, 1996). Reaction with these organic contaminants result in
the generation of disinfecting by products (DBPs), the simplest of which are the
trihalomethanes (THMs). The nature of these products and the extent to which
they are generated depends upon the prevailing physical and chemical conditions
(PWTAG, 1995). However, they are generally undesirable as they are all at least
suspected carcinogens, teratogens and mutagens (Gosling, 1996).
water treatment (MWT)
1.2.1 Chemical effects The application of magnetic
treatment to water has a long history, and has been used mostly to remove and
control scale deposition (Donaldson, 1988; Baker and Judd, 1995). Calcium
carbonate scale is estimated to cost industry around £ 1 billion per year
(Darvill, 1993). The benefits of magnetic water treatment are claimed to include
energy and water savings along with a range of benefits which prolong the life
of the system's component parts and hence the life of the system itself.
Magnetic treatment has been shown to stabilize pH, eliminate corrosion, reduce
downtime, maintenance and cleaning costs and bacteria and remove the risks
associated with the handling of chemical detergents such as sodium hypochlorite
used in swimming pool water treatment (Ifill, 1994). Magnetic treatment has been
successful in a range of systems including industrial heat exchangers, cooling
towers, water treatment plants and household use (Baker and Judd, 1995), and may
prove useful to the leisure industry in reducing the heating and disinfecting
expenses involved in managing swimming pools. In addition to this physical water
treatment is more environmentally acceptable than the use of strong oxidizing
1.2.2 Biological effects
Water is the major component of bacterial
cells and the dissolved ion content in the intracellular water is the source of
nutrition for the cell. One report shows that magnetic treatment of water can
enhance the solubility of ions in the water, and proposes this the mechanism by
which magnetic fields affect biological systems (Lin and Yotvat, 1990). It has
also been proposed that magnetism may affect ion polarity, increasing membrane
permeability and hence the amount of chlorine which can enter a cell, thereby
enhancing its disinfecting properties (Ayrapetyan et al, 1994). A number of
reports exist investigating the mechanisms by which magnetically treated water
affects the cells and micro-organisms, the observed effects apparently varying
from stimulatory to inhibitory depending on field strength and frequency of the
magnetic field (Chizhov, 1975; Goodman et al, 1976; Moore, 1979; Berg, 1993).
Many reports are concerned with the nature of the medium in which the
micro-organisms exist (Berg, 1993; Okuno et al, 1993). Strong magnetic fields
have been seen to enhance the growth of the model bacterium Escherichia coli
cultured on a range of growth media (Okuno et al, 1993), but on the other hand,
low strength alternating and pulsed fields have been shown to inhibit growth
(Smith et al, 1993).
1.3 Magnetic treatment of swimming pool water
The last few
years have seen the development of magnetic treatment devices (MTDs) for,
amongst other applications, swimming pool water treatment. It is claimed by the
suppliers of these devices that such devices have a number of beneficial effects
§ The reduction of scale.
§ The suppression of chlorine
§ The inhibition of microbial growth.
Of special interest, and
as a direct consequence of the above, is filter surface loading or fouling.
Fouling of sand filters in swimming pool treatment can be largely attributed to
clogging of the surface of the filter by organic materials, such that
backflushing becomes necessary long before the full capacity of the filter has
been reached. The application of a magnetic field via the specified magnetic
treatment device might thus be expected to reduce the fouling of the filters by:
a) Inhibition of biological growth and/or
b) Enhanced breakdown of organic
materials due to the maintenance of higher chlorine levels in the water
these two key phenomena that form the basis of the study.
One of PWTAGs stated
main principles is that "the less disinfectant and other chemicals needed to
maintain good water quality, the better", and that "the only chemical you should
use is a lot of water" (Gosling, 1996). In addition to this basic premise,
enhanced disinfecting would be of great benefit in terms of cost. At the moment,
pools in the UK spend an average of £500 per annum on disinfectants. Should the
25% saving previously claimed be possible, the 1600 pools in this country would
save a total of £2 million on disinfecting costs per year (Ifill, 1994).
To assess the extent of the possible benefit MWT could have
for the treatment of swimming pool water, the literature survey covered the
1) The operation and standards of swimming pools
Disinfecting of swimming pools*
3) Chemical contamination of swimming pools
Biological contamination of swimming pools
5) Factors affecting disinfecting
Magnetic treatment of water
7) The effects of magnetic fields on biological
8) The effects of magnetic fields on chemical activity
"disinfecting" is defined as the conscious inactivation of pathogenic organisms
2.1 The operation and standards of swimming pools
The Pool Water
Treatment Advisory Groups (PWTAG’s) Pool Water Guide (1995) sets out guidelines
and outlines legislation which ensures water quality and therefore public
safety. The regulations control water temperature and chemical additions and
bather load in order to ensure bather safety and good water quality. The
treatment of swimming pool water is made compulsory by The Swimmers Pools
Regulations of September 1991 4 (1) in Britain, and on the continent by other
European legislation such as DIN standard 19 643 in Germany. PWTAG guidelines
give maximum bather load as 1 bather per 2.5 m² for safety, whereas the
Department of Environment (DOE) uses the formula below in order to maintain
water quality. PWTAG lay down strict guidelines for pool water quality in terms
of suspended and dissolved solids as well as physical properties (Table 1).
The study was conducted on the laboratory scale. The device was tested
on simulated swimming pool water of known chemical and microbiological
composition using a water of specification within PWTAG recommended
concentration ranges (Table 8). Tests were restricted to relatively hard waters
where scaling is more visible, although effects on scale formation were not
rigorously quantified. Faecal coliform was used as the microbiological
contaminant throughout the course of study, and human urine and sweat analogues
were added (specified in Table A1, Appendix A). All tests were conducted using
Spectrosol grade sodium hypochlorite with 12% free available chlorine (w/v) as
the disinfectant and calcium bicarbonate to represent hardness of 200 ppm as
CaCO3, which would encourage scale formation while remaining within PWTAG’s
Limiting values of physiochemical parameters
- Component Low High
- Sodium Hypochlorite (mg/l) 0.42 1.40 1.05
- Free chlorine (mg/l) 0.50
- Sodium bicarbonate (mg/l) 168.00 336.00 336.00
- Calcium Chloride (mg/l)
55. 00 222.00 222.00
- Sodium Humate (mg/l) 0.00 0.02 0.01
- Sodium Chloride (mg/l)
0.00 2000.00 0.00
- Sodium Sulphate (mg/l) 0.00 1500.00 0.00
- PH 7.20 7.80 7.80
- Temperature (°C) 28.00 32.00 32.00
- *Body fluid simulant (ml/l) 0.00 0.05 0.05
Simple analogue of human urine and sweat: Table A1.
was focused on the suppression of chlorine desorption, and increased
bactericidal action. Previous work within the School of Water Sciences (Ifill,
1994) has revealed that magnetic treatment has a small but significant effect on
the retention of free chlorine, as well as on calcium carbonate scale formation.
It was intended that further work be carried out to verify trends observed in
the previous study, and determine the extent to which the observed chlorine
retention affects the formation of THM by-products. In addition, the direct
influence of magnetic forces on bacteria viability will be studied.
The aim of
the work was to test the efficacy of a magnetic treatment device (Magnetizer) in
conditioning simulant swimming pool water so as to enhance chemical
disinfecting. To this end, the effect of the magnetic treatment on both
microbiological and chemical activity was to be quantified.
It was intended that
quantitative or semi-quantitative assessment of the effect of MTD’s on free
chlorine level, combined chlorine level, disinfecting by-product formation, with
specific reference to trihalomethanes and disinfecting capability for faecal
coliform would be provided, and that the results would refer to chemical
conditions simulating those persisting in a normal swimming pool.
chloroform concentrations after an initial free chlorine dose of 0.4 ppm
of mean chloroform concentrations at 0.4 ppm initial dose
Source of Variation
Sum of Squares DF Mean Square F Sig of F
Covariates Combined CI (ppm)Free CI
(ppm) PH Temperature (°C)Time (hours) 1.0900.9760.1901.76975.514 11111
Main Effect Presence of MTD 20.429 1 20.429 5.660 0.000
Explained Residual Total
120.415283.651404.006 68086 20.0693.5464.698 19.000 0.000
Summary of effects of
- The pH of pool simulant solutions increased when organic compounds were
present and decreased when they were absent.
- No changes in solution
conductivity were found. Kulish comment: This is normal as there is no
additional water or chemicals and evaporation has been reduced due to the
- No scale was formed, so no conclusive results were obtained.
Kulish comment: With the constant magnetic conditioning and softening treatment,
no scale could form.
- The turbidity of the solutions increased by an
undetermined amount. Kulish comment: The Monopolar Magnetic Treatment provides
ultra cleaning which, if filtered normally, the turbidity disappears completely
resulting in crystal clear water. Users have reported the
clearest water they
have ever seen with extremely low maintenance.
- No direct biocidal effects
were observed. Kulish comment: See #6.
- The cell death rate of E coli was
significantly raised owing to increased aqueous chlorine. Kulish comment: Test
showed 86% reduction of bacteria by MWT before chlorine treatment. Usage of both
chlorine and MWT maintains bacteria-free water.
- Concentrations of free
chlorine in solution were significantly increased by MWT at 0.8 and 1.2 ppm free
chlorine doses. Kulish comment: Increased concentrations of free chlorine mean
that chlorine requirements can be reduced
- Concentrations of combined chlorine
in solution were significantly increased by MWT at and 1.2 ppm free chlorine
doses. Kulish comment: The Kulish Mark 1 Monopole Magnetic Pool Treatment Device
reduced costly sanitizer requirements. Further empirical testing indicates a
standard 30-50% reduction of chlorine is required to maintain proper sanitizer
The Mark 3 Enviromagnetics Pool/Spa Conditioners provide greater power
for better results.
- Cell kill was improved at 0.4, 0.8 and 1.2 ppm initial
free chlorine doses.
- Chloroform production was suppressed at 0.4 and 1.2 ppm
initial free chlorine doses; at 0.4 ppm this was significant.