Introduction
Backyard pools can be a great source of entertainment
and relaxation for the whole family. Many real
estate developers give particular care to developing
backyard pools mainly for its recreational value
and the fact that the whole family benefits from
it. However, backyard pools need to be kept clean
to prevent many diseases that are transmitted
through water. Although the personal hygiene of
the people who use the pool is very important,
it is essential that the pool is also kept clean
and tidy. Since the water in the pool cannot be
changed at will, there are a host of chemicals
that are used to keep the pool clean and free
from disease causing bacteria and viruses that
can causes serious damage to the skin and the
respiratory canals of the human body. On the other
hand, the pollution caused by the residue of these
chemicals is also detrimental to human health.
For example, the residual chemicals that may remain
in the water after water treatment can pose skin
rashes and allergies especially to young children.
This paper will detail the various chemicals and
their harmful effects to humans.
Analysis
Since it is imperative to use chemicals in the pools to eliminate the hazards posed by water borne pathogens, it is very essential to use those chemicals that are not harmful to the body. Since there are no chemicals that are perfectly harmless to the body, it becomes important to choose those chemicals that are least harmful to the body but most effective against a range of water borne pathogens. Some of the chemicals that are used in treating back yard pools and their effect on the environment are detailed below.
Chlorine
Chlorine has been the universal chemical that
has been used to clean pools and water bodies
for human consumption and recreation. This is
perhaps because of the fact that chlorine can
contain bacterial growth and retards the growth
of many microorganisms, algae and even come unwanted
animals. Safe chlorine is measured in a scale
of 0.5 to 3.0 ppm. It is recommended that the
chlorine content of the water be maintained at
1.0 to 1.5 ppm in order to prevent the growth
of water plants and microbes and also to keep
the water clear and clean. Chlorine treatment
is recommended twice every month to ensure clean
water. Chlorine is best added in the night because
of two reasons. One, the added chlorine has the
chance to disinfect the pool for the whole night
and two, sunlight destroys chlorine and depletes
it rapidly [Author not known, 2004]. It is always
advisable to maintain the amount of chlorine in
cooler months to 1.0 ppm, while in the summer
months the adequate count could be 1.5 ppm. Cyanuric
acid may be added to maintain the level of free
chlorine in the water. Cyanuric acid is also called
as stabilizer and 25 to 40 ppm cyanuric acid may
be added to maintain adequate chlorine levels.
Cyanuric acid addition causes the pH in the water
to drop.
pH
pH gives the acidic content of the water. A pH count less than 7 is acidic while a pH count greater than 7 is alkaline. Although 7 represent neutral pH, it is always advisable to maintain the water at a slight alkaline range, which is above pH 7 in order to prevent staining and corrosion of the pool. An ideal pH range would be between 7.4 and 7.6. pH at this range is not corrosive to the body and also is not corrosive to the pool surface. Usually in pools, muriatic acid is added to lower the pH values and soda ash is used to raise the pH whenever needed. A constant monitoring of the pH values is required to maintain clear and healthy water. Lower pH will promote anaerobic decomposition, which may give rise to pungent smell and undesired color in the water. Similarly higher pH may encourage the growth of certain algae and also discolor the water. Acids that are used to maintain pH must be added in the morning and never in the evening since the sunlight action will attenuate their potential to irritate the skin. It is also required that no acid be added when chlorine is added to the water.
Maintaining the alkalinity and acidity of the
water is of paramount importance. Higher alkalinity
will cause scaling of the pool walls, while lower
alkalinity can cause corrosion of the pool plaster,
pumps and the pipes in the pool [Author not known,
2004]. According to standards, ideal alkalinity
is 19 to 20 ppm. Baking soda may be added to control
alkalinity in the water. The pH and alkalinity
of the water will change from season to season
and even on a daily basis according to the source
from which the water is taken. It is imperative
that the pH levels of the water are maintained
every day in order to keep the water clean and
safe for use.
Hardness
Water hardness is caused by salts of calcium and magnesium. In most cases, water that is sourced from taps or wells will have some amount of minerals in it. In water bodies which are not drained every day, the evaporation of water will cause the concentration of such salts, which can have adverse effects on the skin of the people who use the pools. Much research has pointed out that consumption of hard water can cause many diseases in the long run. Hence, hard water in the pool is always unsafe considering that the water may be consumed accidentally by those who use the pool. Hardness of the pool water has to be treated very carefully under supervision. An ideal level of calcium in the pools would be between 200 and 300 ppm. Ideal hardness may be attained by adding calcium if needed. It is advisable to drain off the water when the hardness reaches 600 ppm.
Environmental factors
The major environmental factors that vary in a pool are temperature, solids and oxygen content. Temperature variations can cause many chemical reactions in the pool. Excess temperatures can cause damage to the pool equipments while lower temperatures can promote algal growth. Solids accumulate after extensive use of the pool and may encourage bacterial and fungal growth. Similarly, depletion of oxygen content may cause anaerobic reactions that can create unwanted flavors and smell in the water.
Calcium Hypochloride Versus Lithium Hypochloride
Calcium hypochloride and lithium hypochloride are chemicals that are used as bleaching agents in the pools. They help to clean the pool water and releases chlorine in to the water. These chemicals release free chlorine into the water bodies, thereby rendering them clean. Hypochlorite crystals are available for chlorination of the water bodies [Author not known 1, 2004]. Calcium hypochlorite releases more free chlorine than lithium hypochlorite. The percentage of chlorine released by calcium hypochlorite is almost twice that of lithium hypochlorite. However, use of calcium hypochlorite can increase the hardness of water. Hence, extensive use of calcium hypochlorite will require other chemical treatments that will reduce the hardness of water [ Southwest Florida research and education center, 2004].
Chlorine based chemical versus a peroxide or bromine based chemical
Bromine based chemicals are not useful in outdoor pools since they are very susceptible to sunlight. Similarly they are also found to be cancer causing. Peroxide based chemicals use silver based chemicals that are not effective in sanitizing the pool and so other chemicals may be needed for optimum sanitization. In these circumstances chloride sanitizers are the best option. |