Water
Water
Water
Ground water is located below the surface of the earth in spaces between
rock and soil. Ground water is naturally filtered, which might remove some
germs and chemicals depending on the water’s depth and the area’s local
geology. Water that comes from a well is ground water and might receive
some level of treatmentbefore it reaches your tap.
But here in BAGCO, the water is gotten from BOREHOLE (ground water).. The borehole is about 320ft in
depth, there are 6 boreholes in use for BAGCO water treatment plant, each of these borehole is powered by
10Hp (7.5kw) submersible pump and with an average of 8.0L/S output to the surface
WATER TREATMENT PROCESS .
water treatment , process by which undesired chemical compounds,
organic and inorganic materials, and biological contaminants are removed
from water.
There are several methods used in the water purification process, which
include:
(1) physical processes, such as filtration, sedimentation, or distillation;
(2) biological processes, such as sand filters, active carbon;
(3) chemical processes, such as flocculation, chlorination, the use of
ultraviolet light.
Historical evidence suggests that water treatment was recognized and
practiced by ancient civilizations. Basic treatments for water purification
have been documented in Greek and Sanskritwritings,
and Egyptians used alum for precipitation as early as 1500 BCE.
In modern times, the quality to which water must be purified is typically set
by government agencies. Whether set locally, nationally, or internationally,
government standards typically set maximum concentrations of harmful
contaminants that can be allowed in safe water. Since it is nearly impossible
to examine water simply on the basis of appearance, multiple processes,
such as physical, chemical, or biological analyses, have been developed to
test contamination levels. Levels of organic and inorganic chemicals, such
as chloride, copper, manganese, sulfates, and zinc, microbial pathogens,
radioactive materials, and dissolved and suspended solids, as well as pH,
odour, colour, and taste, are some of the common parameters analyzed to
assess water quality and contamination levels.
Most water used in industrialized countries is treated at water treatment
plants. Although the methods those plants use in pretreatment depend on
their size and the severity of the contamination, those practices have been
standardized to ensure general compliance with national and international
regulations. The majority of water is purified after it has been pumped from
its natural source or directed via pipelines into holding tanks. After the
water has been transported to a central location, the process of purification
begins.
STAGES INVOLE IN WATER TREATMENT PROCESS
Screening
screening, which removes large debris such as sticks and trash from the
water such as that from lakes and rivers. Surface water presents a greater
Aeration
facilitate the removal of odour and the exposure of harmful micro-organisms to the
The kind of problem the raw water in BAGCO has, is a fundamental high iron content aside the general
acidic nature of rawest borehole water
Hence, the design of BAGCO water treatment and choice of chemicals engineered towards effective
removal of iron (Fe2+).
From the borehole, water goes into the aeration tower; the aeration tower creates enough surface area for
atmospheric air (oxygen) to come in contact with the raw water. The chemical process allows a mixture of
oxygen and water. The supply of oxygen to water aids the process of oxidation there by creating and
enabling environment for dissolved iron solute (Fe2+) to become oxidized to Fe3+ and been precipitated
out of the water as insoluble solutes of iron (iii) Fe3+.
Just at the base of the aeration tower, the chemicals are allowed to come in by means of dosing pump. The
addition of the chemicals with aeration makes the oxidation process very rapid and obvious as the water
changes color from its usual colorless nature and become brownish indicating that ferric iron (soluble iron)
in water is changing to ferrous iron (insoluble iron) which is brownish in color.
As the water flows into the various compartments of the treatment tank, there is thorough mixture of
chemicals and aerated water and the conversion process of iron (ii) to iron (iii) becomes more obvious and
distinct
From the treatment tank, the water is allowed to flow by gravity into retention tank where the water is
retained and allowed to sediment
Sedimentation is accomplished by decreasing the velocity of the water as its flows
into the retention tank to a point below which the particles will no longer remain in
suspension. When the velocity no longer supports the transport of the particles,
gravity will remove them from the flow.
FILTRATION
the water from retention tank is allowed to flow through filtration channels by means of surface pumps
(also referred to as transfer pumps). The filtration channels are also referred to as FILTER VESSELS.
A typical plant consists of two filter vessels with different filtration media,
the first vessel contains sharp fine sand
A sand filter, or sand water filter, makes use of sand to filter water. The water to be purified slowly sinks
through the sand of the sand filter(,typically 0.75 mm sand 750 mm deep.) leaving the dirt particles from
the water behind in the fine pores of the sand.
and the second contain a specialized material media for the removal of iron and manganese thereby
serving as a final polishing surface for the water, this medium is called by the acronym “BIRM” meaning
back washable iron and manganese removal media. The BIRM consist of hydrolyte and activated carbon.
acts as an insoluble catalyst to enhance the reaction between dissolved oxygen and the iron compounds to
form ferric hydroxide which is then removed through mechanical filtration in the media bed.
Having passed through these two filtration media, the water produced is portable water which could be
used directly for general human use.