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purpose of this article is to convey to the bathing public a knowledge
of the latest processes involved in providing a constant supply
of sterile water at all times.
To minimise the risk of infection from participating in a
bathe in public swimming baths, most local authorities have
installed filtration systems. The system not only reduces risk of
infection to a minimum, but also proves economical in water supply
and heating costs; it also gives an inviting appearance to the water
in the pool at all times, which is so essential to reputation and an
inducement to bathe.
The purification of swimming bath water consists of three
phases:—filtration, aeration and sterilisation.
Filtration is, briefly stated, the removal of suspended matter,
colour and approximately 90 per cent, of bacteria.
Aeration is applied before filtration for the purpose of removal
of offensive and impure gases, and regulating the soluble mineral
contents such as iron, present in solution, being brought into
suspension by oxidisation and thereby easily removed by the filter
beds. Aeration is also applied after filtration to re-saturate the
water with oxygen before re-entering the bath, giving a bright and
sparkling appearance and assisting to maintain its purity and
tonic effects upon the bathers.
Sterilisation is a most important part of the purification
process, for although the water may possess a lovely clear and
sparkling appearance to the eye after filtration, it cannot be said
to be sterile unless it has been through the process of chlorination.
'Bacteria ' is a word that conjures up terrible ideas to the minds
of many people; although it may be safely said that there are many
kinds of organisms which are in no way harmful to the human
being, yet at the same time precautions must be taken to eliminate
as far as possible those organisms which are of a harmful nature.
It has been definitely proved for several years that if swimming
bath water is to be maintained in a bacteriologically safe condition,
it must be subjected to a process of continuous disinfection
by a re-agent such as chlorine gas.
Chlorination as the process is termed, should always be a
continuous process, not merely at night when bathing has ceased,
as such intermittent practice can only partly achieve its objective