Utilities 2 Midterm M7 Flashcards
Water is composed of two elementary substances.
Hydrogen and Oxygen
3 states of water
Liquid - 840 times heavier than air
Solit - Ice
Gas - Vapor or steam 133 times heavier than air
Sources of water
Rainfall
Natural surface
Underground surface
adv and disav of rainfall
- Advantages: Obtained from roofs and
watersheds. It is soft pure and good on
places where there is an abundant
rainfall. - Disadvantages: Hard to store for a long
time as it will be a breeding place for
mosquitoes, requires big containers for
storing big quantities for long uses, roofs
may not be clean, bad for places that
receives a little amount of rainfall.
Adv and disadv of natural surface
- Advantages: Obtained from ponds, lakes,
rivers. Easy to procure and good for
locality near such bodies of water. - Disadvantages: Dangerous because it
contains large amounts of bacteria,
organic and inorganic substances of
varying quantities.
adv and disadv of underground surface
- Advantages: Obtained from below
ground surfaces by means of mechanical
equipment. More water ca be obtained
depending by equipment used and
locality. - Disadvantages: Because of various
organic matter and chemical elements
present, it requires treatment of various
nature, such as sedimentation, chemical,
filtration, aerations.
Methods of purification and treatment of water
Sedimentation
Chemical Treatments
Filtration
Aeration
articles that are suspended in the water are allowed to stay in a container so that they will settle in the bottom, then drawing the water out, leaving these sediments in the container.
Sedimentation
water are given chemical treatments to kill the harmful bacteria present and to cure the turbid taste or mud taste, remove clay, slats, iron, etc. Commonly used chemical is chlorine.
Chemical treatment
water is filtered on various processes, so as to remove the particles of vegetable matter, mud, and other particles of matter present in the water, most commonly used materials are sand and gravel.
Filtration
raw water is made to pass on pipes of tiny sieves and exposed to air of fine mist.
Aeration
When excavated by hand are called
____________ – for shallow water.
Dug wells
When sunk by machine are called
____________ and are classified as driven – when the water is obtained from
loose formation above solid rock such
as sand and gravel and drilled wells –
when the water is tapped from the
fissures.
Deep wells
Types of wells according to the method of construction
Dug wells
Bored well
Driven well
Drilled well
Truck mounted drilling machine
Drilled well by jetting
a well 0.90 to 6.00 meter in diameter dug through soft upper soil. The sides may be of masonry or concrete to prevent from caving-in. It is necessary that the well should be impervious to a depth of at least 3.00 meters.
Dug wells
it is constructed using either hand or power driven earth auger. A well casing is lowered to the bottom of the hole. Cement grout is poured into the gap between the hole and the casing to prevent
contamination.
Bored well
it is done by forcing into the earth a 60 to 90 cm long piece of perforated steel tube attached to a pointed screen called a “drive point”
Driven well
A drilling rig is used to drill the well hole and then casing pipe is forced down the hole to prevent it from caving in. When a
water bearing stratum of sufficient capacity is found, a well screen is set in place to permit the water to flow into the casing and to hold back the fine material.
Drilled well
The depth of drilled well is limited only by the distance one must dig to obtain an adequate supply of fresh water, even down to 450 meters (equivalent to a 130 storey building).
Truck mounted drilling machine
It used whenever the water supply at its
natural pressure cannot be directly piped to a building, tank, or reservoir.
Pump
Types of pump
Lift pump
Force pump
Reciprocating pump
consist of a piston travelling up and down within a cylinder which is connected with a pipe extending down into the source. The piston and the bottom of the cylinder are each provided with a valve opening upward. Upon the piston’s upstroke, valve a closes and valve b opens. Upon the piston’s down stroke valve a opens and b close.
Lift pump
used to deliver water at a point higher than the position of the pump itself, when the plunger descends, the valve a is closed and
the water in the cylinder is forced out through the valve b and up to the storage. When the plunger is raised valve b is closed and a open to admit water to the cylinder.
Force pump
include that class of pumps in which the piston moves to and from, either horizontally or vertically.
Reciprocating pump
