Abstract
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INTRODUCTION
WATER DISTRIBUTION
Generally, water has numerous purposes: drinking; bathing; washing clothes
and dishes; cooking; flushing toilet, irrigation, just to name a few. Its significance
cannot be over stressed. This is on the grounds that every day each individual uses
water for one thing or the other.
As water flows throughout the distribution system, microorganisms can
contaminate the flow of water through the pipes, air valves, pump boosters, network
of piping system and sometimes through the plumbing system.
Inability to attain a water quality as high as feasible can open individuals to
the risk of getting diseases that can easily be avoided through percussive methods.
Drinking and domestic use
Household or domestic water is mainly the water used for drinking, washing
and cleaning purposes. Water quality hence is dependent on its micro-constituents
and whether or not it has adverse effects on consumption. Therefore, water
containing harmful or toxic microorganisms and elements is regarded as unfit for
household consumption. Basic examples of toxins found in household water
incorporate microorganisms, for example, protozoa viruses, and bacteria; inorganic
contaminants, for example, salts, metals, radioactive contaminants and small
amounts of organic contaminants.
However, industrial water includes water sources used mainly for industrial
purposes. The quality of water in this scenario is therefore slightly different than the
water meant for consumption purposes. For instance, hard water, which constitutes
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high concentrations of minerals, hampers the effectiveness of soaps or detergents
whereas drinking water should most preferably be hard water because of the
presence of ions such as calcium and magnesium.
On the other hand, environmental water describes water available to the
biosphere and which in some way affects the balance of the ecosystem. Lethal
constituents and high masses of specific microorganisms pose risks for non-drinking
purposes, for example, swimming and irrigation which inhabits the use of domestic
water. The measured quality of water bodies is called Ambient Water Quality.
Importance of good water supply
The quality of water is noted as important not only because it affects health,
but also because it has the tendency to improve it as well. The body is made up of
70% water and the amounts of magnesium and calcium present in any body of
consumable water has the ability to improve bone mass and density.
The elements present in water, depending on their quantities, have the ability
to hamper the effectiveness of industrial machines by causing rust, brittleness,
clogging, bursting, etc. Hence, to ensure the a good standard water quality, there
needs to be an understanding of what pollutants and contaminants upset the balance
of water constituents is necessary to ensure that balance is not tempered with.
Trace levels of ammonia, barium, lead, copper, nitrites, radium, selenium,
etc. have negative effects on humans if present in large amounts and can only be
curtailed via treatment. There is the point-of-use treatment which involves the
treatment of water at the point of consumption using methods such as reverse
osmosis, ultraviolet technologies and distillation. On the other hand, point-of-entry
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involves the treatment of water needed for household chores using methods such as
ion replacement and filtration. On the line of water distribution or supply, filtration
comes as it is a key process in ensuring good water quality.
Description of the purification methods
Physical Form of Water Purification: It is thus named because it is concerned with
filtration techniques. Filtration is used while purifying water because it effectively
rids the said portion of water of particles, silts or debris. Sometimes, for special
purposes, specific filters capable of filtering out bacterial form can be engaged. A
few examples of physical purification include:
1. Screen: Usually used to remove large contaminants like leaves and twigs.
2. Sand Filtration: It is a vigorous process used to remove suspended solids
from water. It consists mainly of a filter medium containing multiple sand
layers of different sizes and densities. These solids are precipitated as residue
when water is made to flow through the filter. Because smaller solids have
the ability to pass through sand filters, they are subjected to a secondary
filtration.
3. Cross Flow Filtration: This is a filtration concerned with using a permeable
membrane to remove both salts and dissolved organic matter that only
permeates the contaminants. The filtrate is removed as the process goes on.
The following are types of cross flow filtration: micro-filtration, ultrafiltration and reversed osmosis.
4. Cartridge Filtration: It generally operates effectively and economically on
applications having excessively high contamination levels. They consist of
fibers and are normally used as final processes as polishing filters.
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Chemical Form of Water Purification
1. Chemical Addition: This process mainly consists of agents such as chelating,
oxidizing and reducing agents. They are necessary to add to the water to
prevent the negative effects of hardness, caused by the deposition of elements
2. Clarification: It consists of a series of processes that involves the addition of
coagulants to remove large. Suspended solids. Coagulants help to reduce the
charges of ions causing the particles to gather and form larger particles called
Flocs. These particles are removed as water flows. Further treatment may be
needed because the water may still contain some suspended solids.
3. Deionization and Softening: This is commonly processed through a system
called Ion Exchange. It consists of a tank of synthetic resin which is treated to
selectively absorb certain cations or anions and replace them with desirable
counter-ions until all the available spaces are filled up with ions.
4. Disinfection: Disinfection is one of the most important and widely known
steps in the purification of water for household use. Often referred to as
biocides, they serve the purpose of killing undesired microorganisms in the
water; ozone, chlorine and controlled UV-radiation disinfections are good
examples.
5. Distillation: Distillation is the collection of water vapor, after boiling.
Because most contaminants do not vaporize, with a properly designed
system, the remaining organic and inorganic contaminants and biological
impurities can be obtained.
6. Electro dialysis: Electro dialysis is a complex technique which employs the
use of electrical currents and special membranes – membranes which are
semi permeable to ions based on their charge. Those membranes that
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permeate cations and anions are placed alternately with electrodes on each
side and flow channels between them. The electrodes draw their counter ions
through the membranes, so that these are removed from the water.
Sometimes, the water in cities are pH adjusted to prevent corrosion from
pipes and to prevent the dissolution of lead into the water supplies.
Biological Water Purification
Biological water purification is a process undertaken to lower the load [The
Biological Oxygen Demand (BOD)] of dissolved organic compounds using
Microorganisms such as bacteria to decompose these compounds. There are two
main categories of biological treatment: aerobic treatment where the water is aerated
with oxygen and anaerobic treatment which runs under oxygen free conditions.
Water safety and quality
Water is one of the key fundamental supplements required by the body in
sufficient amount in other for authentic human functioning. It is not produced by the
body. It constitutes some amount of the body fluid, for example: sweat, urine, blood,
saliva, just to name a few. Then again, it can be acquired from the ingestion of food
and fruits.
The nature of water ought to be free from high concentrations of any
pathogenic microorganism that can result in an ailment on intake. Pathogenic
microorganisms can be evident but should not be present in concentrations that can
result in disruption of the body on intake. Throughout the years, there has been much
discussion over the satisfactory concentration of pathogenic microorganisms in
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water. Be that as it may, the United States Environmental Policy Agency (USEPA)
worked up an adequate concentration level that is renowned around the world.
Around the world, diverse health organizations have set principles for water
quality. Out of the different sorts of water sources, water taken into the body ought
not to contain microorganisms like bacteria, and should have a low concentration of
dangerous chemicals (that is, chemicals toxic to humans). The presence of these
microbes in water are evident in nature and testing for specific bacteria can be time
consuming. This is why it is better to use indicator organisms to check if coliforms
exist in water distribution systems.
Water quality is a term most adequately used to insinuate the substance,
physical, organic, and radiological characteristics of water. It should measure the
condition of water bodies in respect to the requirements of one or more life structures
and to any human need. Regularly, the most broadly perceived benchmarks used to
assess water quality relate to wellbeing and the security of human contact and
drinking water. Therefore, the nature of desired water quality fluctuates with
intended usage.
Faults in the system
The following is a list of reasons for water pollution:
• Untreated water from motorways and cleared surfaces when it rains runs-off
conveying sediments, lethal chemicals from the engine of vehicles, pesticides
and composts from gardens, pathogens and microscopic organisms like
bacteria from pet waste and broken septic tanks into nearby water bodies.
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• The increase of nutrients leads to large algal blooms which eventually leads
to reduced amounts of dissolved oxygen in the water after the death and
decomposition of these algae creating hypoxic or “dead zones,” in which
organisms cannot survive.
• Also wastes that are not appropriately discarded wash into drains or get
blown into waterways and turn into debris.