CHAPTER ONE

1.1 INTRODUCTION

Potable water is water that is safe to be used in drink or food preparation. The amount of
drinking water required to maintain good health varies, and depends on physical activity
level, age, health-related issues, and environmental conditions (Ann, 2022; NCEA,
2022). Recent work showed that the most important driver of water turnover which is
closely linked to water requirements is energy expenditure. For those who work in a hot
climate, up to 16 litres a day may be required (Ann, 2022).

Typically in developed countries, tap water meets drinking water quality standards, even
though only a small proportion is actually consumed or used in food preparation. Other
typical uses for tap water include will behing, toilets, and irrigation. Greywater may also
be used for toilets or irrigation. Its use for irrigation however may be associated with
risks. Water may also be unacceptable due to levels of toxins or suspended solids
(Yamadaet al., 2022).

Globally, by 2015, 89% of people had access to water from a source that is suitable for
drinking called improved water source. In sub-Saharan Africa, access to potable water
ranged from 40% to 80% of the population. Nearly 4.2 billion people worldwide had
access to tap water, while another 2.4 billion had access to wells or public
taps. The World Health Organization considers access to safe drinking-water a basic
human right (WHO, 2021).

Water is a basic human need, and access to safe drinking water is a fundamental human
right and an index of living standards (Dinka, 2018). Water is important for drinking,
food security, nutrition supply, industrial development, the economy, ecosystem services,
and the overall health of all species (Kılıç, 2020; Young et al., 2021).
Chemical reactions in human cells must first dissolve in water, which is why water is
referred to as the ‘’universal solvent’’ (Sargen, 2019). Water’s dissolving strength is
comparable to that of other substances, but they lack its chemical stability and capacity to
neutralize concentrated acids and bases (Sargen, 2019). Life would simply not exist
without water.
Although water covers at least 70% of the earth’s surface, only 2.5% of it is freshwater,
with almost all of it trapped in ice and the ground (United States Geological Survey,
2021).

1
Surface water accounts for just over 1.2% of total freshwater, with rivers accounting for
only 0.49% (United States Geological Survey, 2021). However, rivers are the primary
sources of public water and irrigation (National Groundwater Association, 2021).
Riverbanks are also used for recreational and sporting events, as well as tourism (Yahaya
et al., 2021). Some enterprises are also located near rivers because they require water to
operate (Yahaya et al., 2021).
The United Nations describes free access to clean water as a basic human right and one of
the indices of good living (CDC, 2020).Clean water is necessary for social development,
justice and welfare; so important it will be tagged as the earth'smilk (Sharad and Vijay,
2020).On average, an individual needs between 20 and 50 liters of cleanand safe water
daily for drinking and domestic activities (CDC, 2020). Unfortunately, waterquality and
availability are declining worldwide (Sharad and Vijay, 2020).
At least one in six people, particularly in developing nations, lack adequate access to
clean and safe water (NAS, 2017). This phenomenon has contributed significantly to the
rising incidence of many diseases worldwide. Liu et al. (2022) reported that about 1.8
million people, mostly children and women die every year from waterborne diseases like
cholera, diarrhea and dysentery. Increasing environmental pollution due to urbanization
and industrialization had been linked to declining water quality worldwide (Sharad and
Vijay, 2020).
Water is one of the most essential compounds to life on Earth. It forms about 50 to 60%
of body weight and plays a substantial role in all the vital processes of our body (Kawther
and Alwakeel, 2017). Hygienic water is essential for social development, justice and
welfare; so essential that it has been as the earth's milk (Sharad and Vijay, 2020; Yahaya
et al., 2019). Accessibility of clean potable water does not only play a crucial role in
economic development and social welfare, but it is an essential element in health, food
production and poverty reduction (Ashbolt et al., 2019).
Despite its importance, water is the most poorly managed resource in the world. The
public health significance of water cannot be over emphasized. Many infectious diseases
are transmitted by water through the fecal oral route. Diseases contacted through drinking
water kills about five million people annually (WHO, 2021). Therefore, the current study
assess microbial quality of portable drinking water in Anguwar Jeji village, kalgo, Kebbi
state.

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1.2 Statement of the problem

According to the world health organization, about 80% of all illness in developing
countries is related to water and sanitation and 15% of all child mortality below the age
of five years in developing countries is attributed to diarrheal diseases (Yahaya et al.,
2019). Contaminated water is estimated to result in more than half a million deaths per
year. Contaminated water with the lack of sanitation will be estimated to cause about one
percent of disability adjusted life years worldwide. As contaminated water takes its toll
on the health of those exposed, the duration of exposure plays a part in the effects of
certain diseases.
Equally, microbiological parameters include coliform bacteria, E. coli, and specific
pathogenic species of bacteria (such as cholera-causing Vibrio cholerae), viruses,
and protozoan parasites. Originally, fecal contamination will be determined with the
presence of coliform bacteria, a convenient marker for a class of harmful fecal pathogens.
The presence of fecal coliforms (like E. Coli) serves as an indication of contamination
by sewage. Additional contaminants include protozoan oocysts such
as Cryptosporidium sp., Giardia lamblia, Legionella, and viruses (enteric). Microbial
pathogenic parameters are typically of greatest concern because of their immediate health
risk. Therefore, it is imperative to assess the microbial quality of portable drinking water
in Unguwar Jeji, Kalgo, Kebbi state.
1.3 Justification of the study
Water is essential for the survival of all forms of life, and so ensuring access to good
quality water is necessary to prevent diseases and improve the quality of human life.
Water is used domestically, industrially and in agricultural activities. Therefore, it is
susceptible to microbial contamination. Given the importance of water, monitoring and
detection of microbial contamination in water is a major part of public health concern.
Equally, water is essential for survival, therefore there is need to be concern in other to
obtained pure and clean water for consumption by determining the different kind of
microorganisms present to avoid disease causing pathogens.
According to the World Health Organization (WHO), "access to safe drinking-water is
essential to health, a basic human right and a component of effective policy for health
protection." In 1990, only 76 percent of the global population had access to drinking
water. By 2015 that number had increased to 91 percent. The amount of drinking water

3
required to maintain good health varies, and depends on physical activity level, age,
health-related issues, and environmental conditions.
1.4 Aim and Objectives of the Study
1.4.1 Aim
The aim of the study is to assess microbial quality of portable drinking water in Unguwar
Jeji village, kalgo, Kebbi state.
1.4.2 Specific objectives
The specific objectives were to;
i. To enumerate the bacteria and fungi associated with portable water.
ii. To isolate and identify bacteria and fungi associated with portable water.
iii. To determine the prevalence of bacteria and fungi associated with portable
water.

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 CHAPTER TWO

LITERATURE REVIEW

2.1 Potable Water Overview

potable water is water that is used in drink or food preparation Drinking water is water
that is safe to be used as potable water(Davenport et al., 2019).The amount of drinking
water required to maintain good health varies, and depends on physical activity level,
age, health-related issues, and environmental conditions. Recent work showed that the
most important driver of water turnover which is closely linked to water requirements is
energy expenditure. For those who work in a hot climate, up to 16 litres (4.2 US gal) a
day may be required (Ann, 2022).

Typically in developed countries, tap water meets drinking water quality standards, even
though only a small proportion is actually consumed or used in food preparation. Other
typical uses for tap water include will behind, toilets, and irrigation. Grey water may also
be used for toilets or irrigation. Its use for irrigation however may be associated with
risks. Water may also be unacceptable due to levels of toxins or suspended solids
(NCEA, 2022).

Figure 2.1: Tap water (Source: NCEA, 2022).

5
Globally, by 2015, 89% of people had access to water from a source that is suitable for
drinking – called improved water source. In sub-Saharan Africa, access to potable water
ranged from 40% to 80% of the population. Nearly 4.2 billion people worldwide had
access to tap water, while another 2.4 billion had access to wells or public
taps. The World Health Organization considers access to safe drinking-water a basic
human right (Clasen, 2020).

About 1 to 2 billion people lack safe drinking water. Water can carry vectors of disease.
More people die from unsafe water than from war, then-U.N. secretary-general Ban Ki-
moon said in 2010. Third world countries are most affected by lack of water, flooding,
and water quality. Up to 80 percent of illnesses in developing countries are the direct
result of inadequate water and sanitation. According to a report
by UNICEF and UNESCO, Finland has the best drinking water quality in the world
(Clasen, 2020).

Water is an inorganic compound with the chemical formula H2O. It is a transparent,

tasteless, odorless, and nearly colorless chemical substance, and it is the main constituent
of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as
a solvent). It is vital for all known forms of life, despite not providing food energy, or
organic micronutrients. Its chemical formula, H2O, indicates that each of
its molecules contains one oxygen and two hydrogen atoms, connected by covalent
bonds. The hydrogen atoms are attached to the oxygen atom at an angle of
104.45°. "Water" is also the name of the liquid state of H2O at standard temperature and
pressure (Bainet al., 2019).

Because Earth's environment is relatively close to water's triple point, water exists on
Earth as a solid, liquid, and gas. It forms precipitation in the form of rain and aerosols in
the form of fog. Clouds consist of suspended droplets of water and ice, its solid state.
When finely divided, crystalline ice may precipitate in the form of snow. The gaseous
state of water is steam or water vapor (Bainet al., 2019).

Water covers about 71% of the Earth's surface, with seas and oceans making up most of
the water volume (about 96.5%). Small portions of water occur as groundwater (1.7%), in
the glaciers and the ice caps of Antarctica and Greenland (1.7%), and in the air as vapor,
clouds (consisting of ice and liquid water suspended in air), and precipitation
(0.001%). Water moves continually through the water

6
 cycle of evaporation, transpiration (evapotranspiration), condensation, precipitation,
and runoff, usually reaching the sea (Bainet al., 2019).

Water plays an important role in the world economy. Approximately 70% of

the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies
has been, and continues to be, a major source of food for many parts of the world,
providing 6.5% of global protein. Much of the long-distance trade of commodities (such
as oil, natural gas, and manufactured products) is transported by boats through seas,
rivers, lakes, and canals. Large quantities of water, ice, and steam are used for cooling
and heating in industry and homes (Yamadaet al., 2022).

Water is an excellent solvent for a wide variety of substances, both mineral and organic;
as such, it is widely used in industrial processes and in cooking and will behing. Water,
ice, and snow are also central to many sports and other forms of entertainment, such as
swimming, pleasure boating, boat racing, surfing, sport fishing, diving, ice skating, and
skiing (Bainet al., 2019).

2.2 Etymology of water

The word water comes from Older English language wæter, from Proto-
Germanic *watar (source also of Old Saxon watar, Old Frisian language wetir, Dutch
language water, Old High German language wazzar, German language will
beser, vatn, Gothic language (wato), from Proto-Indo-European *wod-or, suffixed form
of root *wed- ('water'; 'wet'). Also cognate, through the Indo-European root,
with Greek ύδωρ (ýdor; from Ancient Greek ὕδωρ (hýdōr), whence
English 'hydro-'), Russian вода́ (vodá), Irish uisce, and Albanian ujë. Hausa “ruwa”
(USEPA, 2023).

2.3 Water resources

Water covers approximately 70% of the Earth's surface, where approximately 97.2% of it
is saline, only 2.8% fresh. Potable water is available in almost all populated areas of the
Earth, although it may be expensive and the supply may not always be sustainable.
Sources where water may be obtained include springs, hyporheic zones and aquifers, and:

 Precipitation which includes rain, hail, snow, fog, etc.

 Surface water such as rivers, streams, glaciers
 Biological sources such as plants

7
 Desalinated seawater
 Water supply network
 Atmospheric water generators (Conroy et al., 2019).

Threats for the availability of water resources include: water scarcity, water
pollution, water conflict, insufficient well-depth, droughts and overpumping and
the effects of climate change (Rose et al., 2023).

2.4 Historical perspective of water

One factor in estimating when water appeared on Earth is that water is continually being
lost to space. H2O molecules in the atmosphere are broken up by photolysis, and the
resulting free hydrogen atoms can sometimes escape Earth's gravitational pull
(see: Atmospheric escape). When the Earth will be younger and less massive, water
would have been lost to space more easily. Lighter elements like hydrogen
and helium are expected to leak from the atmosphere continually, but isotopic ratios of
heavier noble gases in the modern atmosphere suggest that even the heavier elements in
the early atmosphere were subject to significant losses (UN, 2020).

In particular, xenon is useful for calculations of water loss over time. Not only is it a
noble gas (and therefore is not removed from the atmosphere through chemical reactions
with other elements), but comparisons between the abundances of its nine stable isotopes
in the modern atmosphere reveal that the Earth lost at least one ocean of water early in its
history, between the Hadean and Archean eons (Hobbins,2023).

Any water on Earth during the latter part of its accretion would have been disrupted by
the Moon-forming impact (~4.5 billion years ago), which likely vaporized much of
Earth's crust and upper mantle and created a rock-vapor atmosphere around the young
planet. The rock vapor would have condensed within two thousand years, leaving behind
hot volatiles which probably resulted in a majority carbon dioxide atmosphere with
hydrogen and water vapor (Hobbins, 2023).

Afterward, liquid water oceans may have existed despite the surface temperature of
230 °C (446 °F) due to the increased atmospheric pressure of the CO 2 atmosphere. As the
cooling continued, most CO2 will be removed from the atmosphere by subduction and
dissolution in ocean water, but levels oscillated wildly as new surface and mantle cycles
appeared (Conroy et al., 2019).

8
Geological evidence also helps constrain the time frame for liquid water existing on
Earth. A sample of pillow basalt (a type of rock formed during an underwater eruption)
will be recovered from the Isua Greenstone Belt and provides evidence that water existed
on Earth 3.8 billion years ago. In the Nuvvuagittuq Greenstone Belt, Quebec, Canada,
rocks dated at 3.8 billion years old by one study and 4.28 billion years old by
another show evidence of the presence of water at these ages (Conroy et al., 2019).

If oceans existed earlier than this, any geological evidence has yet to be discovered
(which may be because such potential evidence has been destroyed by geological
processes like crustal recycling). More recently, in August 2020, researchers reported that
sufficient water to fill the oceans may have always been on the Earth since the beginning
of the planet's formation (Yamada et al., 2022).

Unlike rocks, minerals called zircons are highly resistant to weathering and geological
processes and so are used to understand conditions on the very early Earth. Mineralogical
evidence from zircons has shown that liquid water and an atmosphere must have existed
4.404 ± 0.008 billion years ago, very soon after the formation of Earth. This presents
somewhat of a paradox, as the cool early Earth hypothesis suggests temperatures were
cold enough to freeze water between about 4.4 billion and 4.0 billion years ago (Yamada
et al., 2022).
Other studies of zircons found in Australian Hadean rock point to the existence of plate
tectonics as early as 4 billion years ago. If true, that implies that rather than a
hot, molten surface and an atmosphere full of carbon dioxide, early Earth's surface will
be much as it is today. The action of plate tectonics traps vast amounts of CO 2, thereby
reducing greenhouse effects, leading to a much cooler surface temperature and the
formation of solid rock and liquid water (Yamada et al., 2022).
2.5 Properties of water

Water (H2O) is a polar inorganic compound. At room temperature it is

a tasteless and odorless liquid, nearly colorless with a hint of blue. This
simplest hydrogen chalcogenide is by far the most studied chemical compound and is
described as the "universal solvent" for its ability to dissolve many substances. This
allows it to be the "solvent of life": indeed, water as found in nature almost always
includes various dissolved substances, and special steps are required to obtain
chemically pure water. Water is the only common substance to exist as a solid, liquid,
and gas in normal terrestrial conditions (Kostyla et al., 2019).

9
2.5.1 States of water

Along with oxidane, water is one of the two official names for the chemical
compound H2O, it is also the liquid phase of H2O. The other two common states of
matter of water are the solid phase, ice, and the gaseous phase, water vapor or steam. The
addition or removal of heat can cause phase transitions: freezing (water to
ice), melting (ice to water), vaporization (water to vapor), condensation (vapor to
water), sublimation (ice to vapor) and deposition (vapor to ice) (Fine and Millero, 2021).

2.5.2 Density of water

Water differs from most liquids in that it becomes less dense as it freezes. In 1 atm
pressure, it reaches its maximum density of 999.972 kg/m3 (62.4262 lb/cu ft) at 3.98 °C
(39.16 °F), or almost 1,000 kg/m3 (62.43 lb/cu ft) at almost 4 °C (39 °F). The density of
ice is 917 kg/m3 (57.25 lb/cu ft), an expansion of 9%. This expansion can exert enormous
pressure, bursting pipes and cracking rocks (Nave, 2017).

In a lake or ocean, water at 4 °C (39 °F) sinks to the bottom, and ice forms on the surface,
floating on the liquid water. This ice insulates the water below, preventing it from
freezing solid. Without this protection, most aquatic organisms residing in lakes would
perish during the winter (UKNPL, 2016).

2.5.3 Magnetism

Water is a diamagnetic material. Though interaction is weak, with superconducting

magnets it can attain a notable interaction (Gleick, 2019).

2.5.4 Phase transitions

At a pressure of one atmosphere (atm), ice melts or water freezes (solidifies) at 0 °C

(32 °F) and water boils or vapor condenses at 100 °C (212 °F). However, even below the
boiling point, water can change to vapor at its surface by evaporation (vaporization
throughout the liquid is known as boiling). Sublimation and deposition also occur on
surfaces. For example, frost is deposited on cold surfaces while snowflakes form by
deposition on an aerosol particle or ice nucleus. In the process of freeze-drying, a food is
frozen and then stored at low pressure so the ice on its surface sublimates (Ben-Naim.
and Ben-Naim, 2021).

The melting and boiling points depend on pressure. A good approximation for the rate of
change of the melting temperature with pressure is given by the Clausius–Clapeyron

10
relation:where and are the molar volumes of the liquid and solid phases, and is the
molar latent heat of melting. In most substances, the volume increases when melting
occurs, so the melting temperature increases with pressure. However, because ice is less
dense than water, the melting temperature decreases. In glaciers, pressure melting can
occur under sufficiently thick volumes of ice, resulting in subglacial lakes (Fine and
Millero, 2021).

The Clausius-Clapeyron relation also applies to the boiling point, but with the liquid/gas
transition the vapor phase has a much lower density than the liquid phase, so the boiling
point increases with pressure. Water can remain in a liquid state at high temperatures in
the deep ocean or underground. For example, temperatures exceed 205 °C (401 °F)
in Old Faithful, a geyser in Yellowstone National Park. In hydrothermal vents, the
temperature can exceed 400 °C (752 °F) (Nave, 2017).

At sea level, the boiling point of water is 100 °C (212 °F). As atmospheric pressure
decreases with altitude, the boiling point decreases by 1 °C every 274 meters. High-
altitude cooking takes longer than sea-level cooking. For example, at 1,524 metres
(5,000 ft), cooking time must be increased by a fourth to achieve the desired
result. (Conversely, a pressure cooker can be used to decrease cooking times by raising
the boiling temperature). In a vacuum, water will boil at room temperature (UKNPL,
2016).

2.5.5 Triple and critical points

On a pressure/temperature phase diagram (see figure), there are curves separating solid
from vapor, vapor from liquid, and liquid from solid. These meet at a single point called
the triple point, where all three phases can coexist. The triple point is at a temperature of
273.16 K (0.01 °C; 32.02 °F) and a pressure of 611.657 pascals (0.00604 atm;
0.0887 psi); it is the lowest pressure at which liquid water can exist. Until 2019, the triple
point will be used to define the Kelvin temperature scale (Gleick, 2019).

The water/vapor phase curve terminates at 647.096 K (373.946 °C; 705.103 °F) and
22.064 megapascals (3,200.1 psi; 217.75 atm). This is known as the critical point. At
higher temperatures and pressures the liquid and vapor phases form a continuous phase
called a supercritical fluid. It can be gradually compressed or expanded between gas-like
and liquid-like densities; its properties (which are quite different from those of ambient
water) are sensitive to density (Ben-Naim. and Ben-Naim, 2021).

11
For example, for suitable pressures and temperatures it can mix freely with nonpolar
compounds, including most organic compounds. This makes it useful in a variety of
applications including high-temperature electrochemistry and as an ecologically benign
solvent or catalyst in chemical reactions involving organic compounds. In Earth's mantle,
it acts as a solvent during mineral formation, dissolution and deposition (Fine and
Millero, 2021).

2.5.6 Phases of ice and water

The normal form of ice on the surface of Earth is Ice Ih, a phase that forms crystals
with hexagonal symmetry. Another with cubic crystalline symmetry, Ice Ic, can occur in
the upper atmosphere. As the pressure increases, ice forms other crystal structures. As of
2019, 17 have been experimentally confirmed and several more are predicted
theoretically (UKNPL, 2016).

The 18th form of ice, ice XVIII, a face-centred-cubic, superionic ice phase, will be
discovered when a droplet of water will be subject to a shock wave that raised the water's
pressure to millions of atmospheres and its temperature to thousands of degrees, resulting
in a structure of rigid oxygen atoms in which hydrogen atoms flowed freely. When
sandwiched between layers of graphene, ice forms a square lattice. The details of the
chemical nature of liquid water are not well understood; some theories suggest that its
unusual behaviour is due to the existence of 2 liquid states (Nave, 2017).

2.5.7 Taste and odor

Pure water is usually described as tasteless and odorless, although humans have specific
sensors that can feel the presence of water in their mouths, and frogs are known to be able
to smell it. However, water from ordinary sources (including bottled mineral water)
usually has many dissolved substances, that may give it varying tastes and odors.
Humans and other animals have developed senses that enable them to evaluate
the portability of water in order to avoid water that is too salty or putrid (Gleick, 2019).

2.5.8 Color and appearance

Pure water is visibly blue due to absorption of light in the region c. 600–800 nm. The
color can be easily observed in a glass of tap-water placed against a pure white
background, in daylight. The principal absorption bands responsible for the color
are overtones of the O–H stretching vibrations. The apparent intensity of the color
increases with the depth of the water column, following Beer's law. This also applies, for

12
example, with a swimming pool when the light source is sunlight reflected from the
pool's white tiles (Fine and Millero, 2021).

In nature, the color may also be modified from blue to green due to the presence of
suspended solids or algae. In industry, near-infrared spectroscopy is used with aqueous
solutions as the greater intensity of the lower overtones of water means that
glass cuvettes with short path-length may be employed. To observe the fundamental
stretching absorption spectrum of water or of an aqueous solution in the region around
3,500 cm−1 (2.85 μm)a path length of about 25 μm is needed. Also, the cuvette must be
both transparent around 3500 cm−1 and insoluble in water; calcium fluoride is one
material that is in common use for the cuvette windows with aqueous solutions (Fine and
Millero, 2021).

The Raman-active fundamental vibrations may be observed with, for example, a 1 cm

sample cell. Aquatic plants, algae, and other photosynthetic organisms can live in water
up to hundreds of meters deep, because sunlight can reach them. Practically no sunlight
reaches the parts of the oceans below 1,000 meters (3,300 ft) of depth (Nave, 2017).

The refractive index of liquid water (1.333 at 20 °C (68 °F)) is much higher than that of
air (1.0), similar to those of alkanes and ethanol, but lower than those
of glycerol (1.473), benzene (1.501), carbon disulfide (1.627), and common types of
glass (1.4 to 1.6). The refraction index of ice (1.31) is lower than that of liquid water
(UKNPL, 2016).

2.5.9 Molecular polarity

In a water molecule, the hydrogen atoms form a 104.5° angle with the oxygen atom. The
hydrogen atoms are close to two corners of a tetrahedron centered on the oxygen. At the
other two corners are lone pairs of valence electrons that do not participate in the
bonding. In a perfect tetrahedron, the atoms would form a 109.5° angle, but the repulsion
between the lone pairs is greater than the repulsion between the hydrogen atoms. The O–
H bond length is about 0.096 nm (Gleick, 2019).

Other substances have a tetrahedral molecular structure, for example, methane (CH4)
and hydrogen sulfide (H2S). However, oxygen is more electronegative than most other
elements, so the oxygen atom retains a negative charge while the hydrogen atoms are
positively charged. Along with the bent structure, this gives the molecule an electrical
dipole moment and it is classified as a polar molecule(UKNPL, 2016).

13
Water is a good polar solvent, dissolving many salts and hydrophilic organic molecules
such as sugars and simple alcohols such as ethanol. Water also dissolves many gases,
such as oxygen and carbon dioxidethe latter giving the fizz
of carbonated beverages, sparkling wines and beers. In addition, many substances in
living organisms, such as proteins, DNA and polysaccharides, are dissolved in water. The
interactions between water and the subunits of these biomacromolecules shape protein
folding, DNA base pairing, and other phenomena crucial to life (hydrophobic effect)
(Ben-Naim. and Ben-Naim, 2021).

Many organic substances (such as fats and oils and alkanes) are hydrophobic, that is,
insoluble in water. Many inorganic substances are insoluble too, including most
metal oxides, sulfides, and silicates (Ben-Naim. and Ben-Naim, 2021).

2.5.10 Hydrogen bonding

Because of its polarity, a molecule of water in the liquid or solid state can form up to
four hydrogen bonds with neighboring molecules. Hydrogen bonds are about ten times as
strong as the Van der Waals force that attracts molecules to each other in most liquids.
This is the reason why the melting and boiling points of water are much higher than those
of other analogous compounds like hydrogen sulfide. They also explain its exceptionally
high specific heat capacity (about 4.2 J/g/K), heat of fusion (about 333 J/g), heat of
vaporization (2257 J/g), and thermal conductivity (between 0.561 and 0.679 W/m/K)
(Fine and Millero, 2021).

These properties make water more effective at moderating Earth's climate, by storing heat
and transporting it between the oceans and the atmosphere. The hydrogen bonds of water
are around 23 kJ/mol (compared to a covalent O-H bond at 492 kJ/mol). Of this, it is
estimated that 90% is attributable to electrostatics, while the remaining 10% is partially
covalent (Nave, 2017).

These bonds are the cause of water's high surface tension and capillary forces.
The capillary action refers to the tendency of water to move up a narrow tube against the
force of gravity. This property is relied upon by all vascular plants, such as trees
(UKNPL, 2016).

14
2.5.11 Self-ionization

Water is a weak solution of hydronium hydroxide – there is an

equilibrium 2H2O ⇔ H3O+ + OH−in combination with solvation of the
resulting hydronium ions (Gleick, 2019).

2.5.12 Electrical conductivity and electrolysis

Pure water has a low electrical conductivity, which increases with the dissolution of a
small amount of ionic material such as common salt.Liquid water can be split into
the elements hydrogen and oxygen by passing an electric current through it—a process
called electrolysis. The decomposition requires more energy input than the heat released
by the inverse process (285.8 kJ/mol, or 15.9 MJ/kg) (Nave, 2017).

2.5.13 Mechanical properties

Liquid water can be assumed to be incompressible for most purposes: its compressibility
ranges from 4.4 to 5.1×10−10 Pa−1 in ordinary conditions. Even in oceans at 4 km depth,
where the pressure is 400 atm, water suffers only a 1.8% decrease in
volume.The viscosity of water is about 10−3 Pa·s or 0.01 poise at 20 °C (68 °F), and
the speed of sound in liquid water ranges between 1,400 and 1,540 meters per second
(4,600 and 5,100 ft/s) depending on temperature. Sound travels long distances in water
with little attenuation, especially at low frequencies (roughly 0.03 dB/km for 1 kHz), a
property that is exploited by cetaceans and humans for communication and environment
sensing (sonar) (Ben-Naim. and Ben-Naim, 2021).

2.5.14 Reactivity

Metallic elements which are more electropositive than hydrogen, particularly

thealkalimetals and alkaline earth metals such
as lithium, sodium, calcium, potassium and cesium displace hydrogen from water,
forming hydroxides and releasing hydrogen. At high temperatures, carbon reacts with
steam to form carbon monoxide and hydrogen (Fine and Millero, 2021).

2.6 Water consumption

2.6.1 Daily consumption

The recommended amount of drinking water for human consumption per day is
variable. It depends on physical activity, age, health, and environmental conditions. In the
United States, the Adequate Intake for total water, based on median intakes, is 3.7 litres

15
(130 imp fl oz; 130 US fl oz) per day for human males older than 18, and 2.7 litres
(95 imp fl oz; 91 US fl oz) per day for human females older than 18 which includes about
80% from beverages and 20% from food. The European Food Safety
Authority recommends 2.0 litres (70 imp fl oz; 68 US fl oz) of total water per day for
adult women and 2.5 litres (88 imp fl oz; 85 US fl oz) per day for adult men (Conroy et
al., 2019).

The common advice to drink 8 glasses (1,900 mL or 64 US fl oz) of plain water per day
is not based on science, and an individual's thirst provides a better guide for how much
water they require rather than a specific, fixed quantity. Americans age 21 and older, on
average, drink 1,043 mL (36.7 imp fl oz; 35.3 US fl oz) of drinking water a day and 95%
drink less than 2,958 mL (104.1 imp fl oz; 100.0 US fl oz) per day. Physical exercise and
heat exposure cause loss of water and therefore may induce thirst and greater water
intake. Physically active individuals in hot climates may have total daily water needs of 6
litres (210 imp fl oz; 200 US fl oz) or more (Clasen, 2020).

The drinking water contribution to mineral nutrients intake is also

unclear. Inorganic minerals generally enter surface water and ground water via storm
water runoff or through the Earth's crust. Treatment processes also lead to the presence of
some minerals. Examples
include calcium, zinc, manganese, phosphate, fluoride and sodium compounds (Hobbins,
2023).

Water generated from the biochemical metabolism of nutrients provides a significant

proportion of the daily water requirements for some arthropods and desert animals, but
provides only a small fraction of a human's necessary intake. There are a variety of trace
elements present in virtually all potable water, some of which play a role in metabolism.
For example, sodium, potassium and chloride are common chemicals found in small
quantities in most waters, and these elements play a role in body metabolism. Other
elements such as fluoride, while beneficial in low concentrations, can cause dental
problems and other issues when present at high levels (Rose et al., 2023).

Fluid balance is key. Profuse sweating can increase the need for electrolyte (salt)
replacement. Water intoxication (which results in hyponatremia), the process of
consuming too much water too quickly, can be fatal. Water makes up about 60% of the
body weight in men and 55% of weight in women. A baby is composed of about 70% to
80% water while the elderly are composed of around 45% (Rose et al., 2023).

16
2.6.2 Household usage

In the United States, the typical water consumption per capita, at home, is 69.3 US
gallons (262 L; 57.7 imp gal) of water per day. Of this, only 1% of the water provided by
public water suppliers is for drinking and cooking. Uses include (in decreasing order)
toilets, will behing machines, showers, baths, faucets, and leaks (Ritchie and Roser,
2018).

2.6.3 Animals

The qualitative and quantitative aspects of drinking water requirements on domesticated

animals are studied and described within the context of animal husbandry. However,
relatively few studies have been focused on the drinking behavior of wild animals
(Conroy et al., 2019).

2.7 Water supply

The most efficient and convenient way to transport and deliver potable water is through
pipes. Plumbing can require significant capital investment. Some systems suffer high
operating costs. The cost to replace the deteriorating water and sanitation infrastructure of
industrialized countries may be as high as $200 billion a year. Leakage of untreated and
treated water from pipes reduces access to water. Leakage rates of 50% are not
uncommon in urban systems (Hobbins, 2023).

Springs are often used as sources for bottled waters. Tap water, delivered by
domestic water systems refers to water piped to homes and delivered to a tap or spigot.
For these water sources to be consumed safely, they must receive adequate treatment and
meet drinking water regulations (Ritchie and Roser, 2018).

Because of the high initial investments, many less wealthy nations cannot afford to
develop or sustain appropriate infrastructure, and as a consequence people in these areas
may spend a correspondingly higher fraction of their income on water. 2013 statistics
from El Salvador, for example, indicate that the poorest 20% of households spend more
than 10% of their total income on water. In the United Kingdom, authorities define
spending of more than 3% of one's income on water as a hardship (Rose et al., 2023).

17
2.8 Water quality

According to the World Health Organization's 2017 report, safe drinking-water is water
that "does not represent any significant risk to health over a lifetime of consumption,
including different sensitivities that may occur between life stages"(Conroy et al., 2019).

Parameters for drinking water quality typically fall within three categories: physical,
chemical, microbiological. Physical and chemical parameters include heavy metals,
trace organic compounds, total suspended solids, and turbidity. Chemical parameters tend
to pose more of a chronic health risk through buildup of heavy metals although some
components like nitrates/nitrites and arsenic can have a more immediate impact. Physical
parameters affect the aesthetics and taste of the drinking water and may complicate the
removal of microbial pathogens (Clasen, 2020).

Microbiological parameters include coliform bacteria, E. coli, and specific pathogenic

species of bacteria (such as cholera-causing Vibrio cholerae), viruses,
and protozoan parasites. Originally, fecal contamination will be determined with the
presence of coliform bacteria, a convenient marker for a class of harmful fecal pathogens.
The presence of fecal coliforms (like E. coli) serves as an indication of contamination
by sewage. Additional contaminants include protozoan oocysts such
as Cryptosporidium sp., Giardia lamblia, Legionella, and viruses (enteric). Microbial
pathogenic parameters are typically of greatest concern because of their immediate health
risk (Rose et al., 2023).

Throughout most of the world, the most common contamination of raw water sources is
from human sewage in particular human fecal pathogens and parasites. In
2006, waterborne diseases were estimated to cause 1.8 million deaths while about 1.1
billion people lacked proper drinking water. In parts of the world, the only sources of
water are from small streams that are often directly contaminated by sewage (Hobbins,
2023).

Pesticides, whether used in agriculture or domestically (e.g. homes, schools, businesses)

are potential drinking water contaminants. Pesticides may be present in drinking water in
low concentrations, but the toxicity of the chemical and the extent of human exposure are
factors that are used to determine the specific health risk (Ann, 2022).

Perfluorinated alkylated substances (PFAS) are a group of synthetic compounds used in a

large variety of consumer products, such as food packaging, waterproof fabrics, carpeting

18
and cookware. PFAS are known to persist in the environment and are commonly
described as persistent organic pollutants. PFAS chemicals have been detected in blood,
both humans and animals, worldwide, as well as in food products, water, air and soil
(Conroy et al., 2019).

Animal testing studies with PFAS have shown effects on growth and development, and
possibly effects on reproduction, thyroid, the immune system and liver. As of 2022 the
health impacts of many PFAS compounds are not understood. Scientists are conducting
research to determine the extent and severity of impacts from PFAS on human
health. PFAS have been widely detected in drinking water worldwide and regulations
have been developed, or are under development, in many countries (Rose et al., 2023).

2.9 Water treatment

Most water requires some treatment before use; even water from deep wells or springs.
The extent of treatment depends on the source of the water. Appropriate technology
options in water treatment include both community-scale and household-scale point-of-
use (POU) designs. Only a few large urban areas such as Christchurch, New
Zealand have access to sufficiently pure water of sufficient volume that no treatment of
the raw water is required (Ritchie and Roser, 2018).

In emergency situations when conventional treatment systems have been compromised,

waterborne pathogens may be killed or inactivated by boiling but this requires abundant
sources of fuel, and can be very onerous on consumers, especially where it is difficult to
store boiled water in sterile conditions. Other techniques, such as filtration, chemical
disinfection, and exposure to ultraviolet radiation (including solar UV) have been
demonstrated in an array of randomized control trials to significantly reduce levels of
water-borne disease among users in low-income countries, but these suffer from the same
problems as boiling methods. Another type of water treatment is called desalination and
is used mainly in dry areas with access to large bodies of saltwater (Hobbins, 2023).

2.9.1 Point of use methods

The ability of point of use (POU) options to reduce disease is a function of both their
ability to remove microbial pathogens if properly applied and such social factors as ease
of use and cultural appropriateness. Technologies may generate more (or less) health
benefit than their lab-based microbial removal performance would suggest (Clasen,
2020).

19
The current priority of the proponents of POU treatment is to reach large numbers of low-
income households on a sustainable basis. Few POU measures have reached significant
scale thus far, but efforts to promote and commercially distribute these products to the
world's poor have only been under way for a few years (Rose et al., 2023).

Solar water disinfection is a low-cost method of purifying water that can often be
implemented with locally available materials. Unlike methods that rely on firewood, it
has low impact on the environment (Conroy et al., 2019).

2.10 Global access

According to the World Health Organization (WHO), "access to safe drinking-water is

essential to health, a basic human right and a component of effective policy for health
protection." In 1990, only 76 percent of the global population had access to drinking
water. By 2015 that number had increased to 91 percent. In 1990, most countries in Latin
America, East and South Asia, and Sub-Saharan Africa were well below 90%. In Sub-
Saharan Africa, where the rates are lowest, household access ranges from 40 to 80
percent. Countries that experience violent conflict can have reductions in drinking water
access: One study found that a conflict with about 2,500 battle deaths deprives 1.8% of
the population of potable water (Ritchie and Roser, 2018).

By 2015, 5.2 billion people representing 71% of the global population used safely
managed drinking water services. As of 2017, 90% of people having access to water from
a source that is suitable for drinking – called improved water source – and 71% of the
world could access safely managed drinking water that is clean and available on-demand
(Davenport et al., 2019).

Estimates suggest that at least 25% of improved sources contain fecal contamination. 1.8
billion people still use an unsafe drinking water source which may be contaminated
by feces. This can result in infectious diseases, such as gastroenteritis, cholera,
and typhoid, among others. Reduction of waterborne diseases and development of safe
water resources is a major public health goal in developing countries. In 2017, almost 22
million Americans drank from water systems that were in violation of public health
standards, which could contribute to citizens developing water-borne illnesses. Safe
drinking water is an environmental health concern. Bottled water is sold for public
consumption in most parts of the world (Ann, 2022).

20
Improved sources are also monitored based on whether water is available when needed
(5.8 billion people), located on premises (5.4 billion), free from contamination (5.4
billion), and within a 30-minute round trip. While improved water sources such as
protected piped water are more likely to provide safe and adequate water as they may
prevent contact with human excreta, for example, this is not always the case. According
to a 2014 study, approximately 25% of improved sources contained fecal contamination
(Rose et al., 2023).

The population in Australia, New Zealand, North America and Europe have achieved
nearly universal basic drinking water services. As of 2015, American households use an
average of 300 gallons of water a day (Hobbins, 2023).

2.10.1 Monitoring

The WHO/UNICEF Joint Monitoring Program (JMP) for Water Supply and Sanitation is
the official United Nations mechanism tasked with monitoring progress towards
the Millennium Development Goal (MDG) relating to drinking-water and sanitation
(MDG 7, Target 7c), which is to: "Halve, by 2015, the proportion of people without
sustainable access to safe drinking-water and basic sanitation" (WHO, 2021).

Access to safe drinking water is indicated by safe water sources. These improved
drinking water sources include household connection,
public standpipe, borehole condition, protected dug well, protected spring, and rain water
collection. Sources that do not encourage improved drinking water to the same extent as
previously mentioned include: unprotected wells, unprotected springs, rivers or ponds,
vender-provided water, bottled water (consequential of limitations in quantity, not quality
of water), and tanker truck water. Access to sanitary water comes hand in hand with
access to improved sanitation facilities for excreta, such as connection to public sewer,
connection to septic system, or a pit latrine with a slab or water seal (Clasen, 2020).

According to this indicator on improved water sources, the MDG will be met in 2010,
five years ahead of schedule. Over 2 billion more people used improved drinking water
sources in 2010 than did in 1990. However, the job is far from finished. 780 million
people are still without improved sources of drinking water, and many more people still
lack safe drinking water (Davenportet al., 2019). Estimates suggest that at least 25% of
improved sources contain fecal contamination and an estimated 1.8 billion people

21
globally use a source of drinking water that suffers from fecal contamination (Conroy et
al., 2019).

The quality of these sources varies over time and often gets worse during the wet
season. Continued efforts are needed to reduce urban-rural disparities and inequities
associated with poverty; to dramatically increase safe drinking water coverage in
countries in sub-Saharan Africa and Oceania; to promote global monitoring of drinking
water quality; and to look beyond the MDG target towards universal coverage (Rose et
al., 2023).

2.10.2 Definitions

A "safely managed drinking water service" is "one located on premises, available when
needed and free from contamination". The terms 'improved water source' and
'unimproved water source' were coined in 2002 as a drinking water monitoring tool by
the JMP of UNICEF and WHO. The term, improved water source refers to "piped water
on premises (piped household water connection located inside the user's dwelling, plot or
yard), and other improved drinking water sources (public taps or standpipes, tube wells or
boreholes, protected dug wells, protected springs, and rainwater collection)" (UNICEF,
2018)

2.10.3 International development

Expanding will beH (Water, Sanitation and Hygiene) coverage and monitoring in non-
household settings such as schools, healthcare facilities, and work places, is included
in Sustainable Development Goal 6.WaterAid International is a non-governmental
organization (NGO) that works on improving the availability of safe drinking water in
some the world's poorest countries (Ann, 2022).

Sanitation and Water for All is a partnership that brings together national governments,
donors, UN agencies, NGOs and other development partners. They work to improve
sustainable access to sanitation and water supply to meet and go beyond the MDG
target. In 2014, 77 countries had already met the MDG sanitation target, 29 were on track
and, 79 were not on-track (Hobbins, 2023).

2.11 Health aspect of water

Contaminated water is estimated to result in more than half a million deaths per
year. Contaminated water with the lack of sanitation will be estimated to cause about one
percent of disability adjusted life years worldwide in 2010. As contaminated water takes

22
its toll on the health of those exposed, the duration of exposure plays a part in the effects
of certain diseases (Rose et al., 2023).

2.11.1 Diarrheal diseases

Over 90% of deaths from diarrheal diseases in the developing world today occur in
children under five years old. According to the WHO, the most common diseases linked
with poor water quality are cholera, diarrhoea, dysentery, hepatitis A, typhoid,
and polio. Malnutrition, especially protein-energy malnutrition, can decrease the
children's resistance to infections, including water-related diarrheal diseases. Between
2000 and 2003, 769,000 children under five years old in sub-Saharan Africa died each
year from diarrheal diseases. As a result from poor water quality and bad sanitation, an
estimated 829,000 people die each year from diarrhoea (WHO, 2021).

Only thirty-six percent of the population in the sub-Saharan region have access to proper
means of sanitation. More than 2,000 children's lives are lost every day. In South Asia,
683,000 children under five years old died each year from diarrheal disease from 2000 to
2003. During the same period, in developed countries, 700 children under five years old
died from diarrheal disease. Improved water supply reduces diarrhea morbidity by 25%
and improvements in drinking water through proper storage in the home and chlorination
reduces diarrhea episodes by 39% (WHO, 2021).

2.11.2 Groundwater pollution

Some efforts at increasing the availability of safe drinking water have been disastrous.
When the 1980s were declared the "International Decade of Water" by the United
Nations, the assumption will be made that groundwater is inherently safer than water
from rivers, ponds, and canals. While instances of cholera, typhoid and diarrhea were
reduced, other problems emerged due to polluted groundwater (Clasen, 2020).

Sixty million people are estimated to have been poisoned by well water contaminated by
excessive fluoride, which dissolved from granite rocks. The effects are particularly
evident in the bone deformations of children. Similar or larger problems are anticipated
in other countries including China, Uzbekistan, and Ethiopia. Although helpful for dental
health in low dosage, fluoride in large amounts interferes with bone formation(Ann,
2022).

Half of Bangladesh's 12 million tube wells contain unacceptable levels of arsenic due to
the wells not dug deep enough (past 100 meters). The Bangladeshi government had spent

23
less than US$7 million of the 34 million allocated for solving the problem by the World
Bank in 1998. Natural arsenic poisoning is a global threat with 140 million people
affected in 70 countries globally. These examples illustrate the need to examine each
location on a case-by-case basis and not assume what works in one area will work in
another (Conroy et al., 2019).

2.12Water regulations

Guidelines for the assessment and improvement of service activities relating to drinking
water have been published in the form of drinking water quality standards such as ISO
24510(Roseet al., 2023).

For example, the EU sets legislation on water quality. Directive 2000/60/EC of the
European Parliament and of the Council of 23 October 2000 establishing a framework for
Community action in the field of water policy, known as the water framework directive,
is the primary piece of legislation governing water (Davenport et al., 2019). This
drinking water directive relates specifically to water intended for human consumption.
Each member state is responsible for establishing the required policing measures to
ensure that the legislation is implemented. For example, in the UK the Water Quality
Regulations prescribe maximum values for substances that affect wholesomeness and
the Drinking Water Inspectorate polices the water companies (Hobbins, 2023).

In the United States, public water systems, defined as systems that serve more than 25
customers or 15 service connections, are regulated by the U.S. Environmental Protection
Agency (EPA) under the Safe Drinking Water Act (Davenport et al., 2019). As of 2019
the EPA has issued 88 standards for microorganisms, chemicals and
radionuclides. The Food and Drug Administration regulates bottled water as a food
product under the Federal Food, Drug, and Cosmetic Act. All public water suppliers in
the US must uphold a certain standard of water quality. If the requirements are met,
Americans can drink their local tap water (Clasen, 2020).

2.12.1 New Zealand

The Water Services Act 2021 brought Taumata Arowai' into existence as the new
regulator of drinking water and will bete water treatment in New Zealand. Initial
activities including the establishment of a national register of water suppliers and
establishing a network of accredited laboratories for drinking water and will be the water
analysis (Conroy et al., 2019).

24
2.12.2 Singapore

Singapore is a significant importer of water from neighbouring Malaysia but also has
made great efforts to reclaim as much used water as possible to ensure adequate provision
for the very crowded city-state. Their reclaimed water is marketed as NEWater.
Singapore updated its water quality regulation in 2019, setting standards consistent with
the WHO recommended standards. Monitoring is undertaken by the Environmental
Public Health Department of the Singaporean Government (WHO, 2021).

2.12.3 United Kingdom

In the United Kingdom regulation of water supplies is a devolved matter to

the Welsh and Scottish Parliaments and the Northern Ireland Assembly. In England and
Wales there are two water industry regulatory authorities (Rose et al., 2023).

Water Services Regulation Authority (Ofwat) is the economic regulator of the water
sector; it protects the interests of consumers by promoting effective competition and
ensuring that water companies carry out their statutory functions. Ofwat has a
management board comprising a Chairman, Chief Executive and Executive and Non-
Executive members. There is a staff of about 240 (Hobbins, 2023).

The Drinking Water Inspectorate (DWI) provides independent assurance that the
privatised water industry delivers safe, clean drinking water to consumers. The DWI will
be established in 1990 and comprises a Chief Inspector of Drinking Water and a team of
about 40 people. The current standards of water quality are defined in Statutory
Instrument 2016 No. 614 the Water Supply (Water Quality) Regulations 2016 (Ritchie
and Roser, 2018).

The functions and duties of the bodies are formally defined in the Water Industry Act
1991 (1991 c. 56) as amended by the Water Act 2003 (2003 c. 37) and the Water Act
2014 (2014 c. 21) (Davenport et al., 2019).

In Scotland water quality is the responsibility of independent Drinking Water Quality

Regulator (DWQR).In Northern Ireland the Drinking Water Inspectorate (DWI) regulates
drinking water quality of public and private supplies. The current standards of water
quality are defined in the Water Supply (Water Quality) Regulations (Northern Ireland)
2017(Rose et al., 2023).

25
2.12.4 United States

The Safe Drinking Water Act requires the U.S. Environmental Protection Agency (EPA)
to set standards for drinking water quality in public water systems (entities that provide
water for human consumption to at least 25 people for at least 60 days a
year). Enforcement of the standards is mostly carried out by state health agencies. States
may set standards that are more stringent than the federal standards (Conroy et al., 2019).

EPA has set standards for over 90 contaminants organized into six groups:
microorganisms, disinfectants, disinfection byproducts, inorganic chemicals, organic
chemicals and radionuclides (Clasen, 2020).

EPA also identifies and lists unregulated contaminants which may require regulation.
The Contaminant Candidate List is published every five years, and EPA is required to
decide whether to regulate at least five or more listed contaminants. Local drinking water
utilities may apply for low interest loans, to make facility improvements, through the
Drinking Water State Revolving Fund (Ann, 2022).

2.13 Effect of water on life

From a biological standpoint, water has many distinct properties that are critical for the
proliferation of life. It carries out this role by allowing organic compounds to react in
ways that ultimately allow replication. All known forms of life depend on water. Water is
vital both as a solvent in which many of the body's solutes dissolve and as an essential
part of many metabolic processes within the body (Gleick, 2021).

Metabolism is the sum total of anabolism and catabolism. In anabolism, water is removed
from molecules (through energy requiring enzymatic chemical reactions) in order to grow
larger molecules (e.g., starches, triglycerides, and proteins for storage of fuels and
information). In catabolism, water is used to break bonds in order to generate smaller
molecules (e.g., glucose, fatty acids, and amino acids to be used for fuels for energy use
or other purposes). Without water, these particular metabolic processes could not exist
(Gleick, 2021).

Water is fundamental to photosynthesis and respiration. Photosynthetic cells use the sun's
energy to split off water's hydrogen from oxygen. Hydrogen is combined
with CO2 (absorbed from air or water) to form glucose and release oxygen. All living
cells use such fuels and oxidize the hydrogen and carbon to capture the sun's energy and
reform water and CO2 in the process (cellular respiration)(Ann, 2022).

26
Water is also central to acid-base neutrality and enzyme function. An acid, a hydrogen
ion (H+ that is, a proton) donor, can be neutralized by a base, a proton acceptor such as a
hydroxide ion (OH−) to form water. Water is considered to be neutral, with a pH (the
negative log of the hydrogen ion concentration) of 7. Acids have pH values less than 7
while bases have values greater than 7 (Gleick, 2021).

2.13.1 Aquatic life forms

Earth surface waters are filled with life. The earliest life forms appeared in water; nearly
all fish live exclusively in water, and there are many types of marine mammals, such as
dolphins and whales. Some kinds of animals, such as amphibians, spend portions of their
lives in water and portions on land. Plants such as kelp and algae grow in the water and
are the basis for some underwater ecosystems. Plankton is generally the foundation of the
ocean food chain (Ann, 2022).

Aquatic vertebrates must obtain oxygen to survive, and they do so in various ways. Fish
have gills instead of lungs, although some species of fish, such as the lungfish, have
both. Marine mammals, such as dolphins, whales, otters, and seals need to surface
periodically to breathe air. Some amphibians are able to absorb oxygen through their
skin. Invertebrates exhibit a wide range of modifications to survive in poorly oxygenated
waters including breathing tubes (see insect and mollusc siphons) and gills (Carcinus).
However, as invertebrate life evolved in an aquatic habitat most have little or no
specialization for respiration in water (Gleick, 2021).

2.14 Effect of water on human civilization

Civilization has historically flourished around rivers and major waterways; Mesopotamia,
one of the so-called cradles of civilization, will be situated between the major
rivers Tigris and Euphrates; the ancient society of the Egyptians depended entirely upon
the Nile. The early Indus Valley civilization (c. 3300 BCE – c. 1300 BCE) developed
along the Indus River and tributaries that flowed out of the Himalayas. Rome will be also
founded on the banks of the Italian river Tiber (Sharad and Vijay, 2020).

Large metropolises like Rotterdam, London, Montreal, Paris, New York City, Buenos
Aires, Shanghai, Tokyo, Chicago, and Hong Kong owe their success in part to their easy
accessibility via water and the resultant expansion of trade. Islands with safe water ports,
like Singapore, have flourished for the same reason. In places such as North Africa and

27
the Middle East, where water is more scarce, access to clean drinking water will be and is
a major factor in human development (Gleick, 2021).

2.14.1 Health and pollution

Water fit for human consumption is called drinking water or potable water. Water that is
not potable may be made potable by filtration or distillation, or by a range of other
methods. More than 660 million people do not have access to safe drinking water
(Wadaet al., 2022).

Water that is not fit for drinking but is not harmful to humans when used for swimming
or bathing is called by various names other than potable or drinking water, and is
sometimes called safe water, or "safe for bathing". Chlorine is a skin and mucous
membrane irritant that is used to make water safe for bathing or drinking. Its use is highly
technical and is usually monitored by government regulations (typically 1 part per
million (ppm) for drinking water, and 1–2 ppm of chlorine not yet reacted with impurities
for bathing water). Water for bathing may be maintained in satisfactory microbiological
condition using chemical disinfectants such as chlorine or ozone or by the use
of ultraviolet light (Sharad and Vijay, 2020).

Water reclamation is the process of converting will betewater (most commonly sewage,
also called municipal will betewater) into water that can be reused for other purposes.
There are 2.3 billion people who reside in nations with water scarcities, which means that
each individual receives less than 1,700 cubic metres (60,000 cu ft) of water annually.
380 billion cubic metres (13×1012 cu ft) of municipal will betewater are produced
globally each year (Fine and Millero, 2021).

Freshwater is a renewable resource, recirculated by the natural hydrologic cycle, but

pressures over access to it result from the naturally uneven distribution in space and time,
growing economic demands by agriculture and industry, and rising populations.
Currently, nearly a billion people around the world lack access to safe, affordable water.
In 2000, the United Nations established the Millennium Development Goals for water to
halve by 2015 the proportion of people worldwide without access to safe water
and sanitation (Gleick, 2021).

Progress toward that goal will be uneven, and in 2015 the UN committed to
the Sustainable Development Goals of achieving universal access to safe and affordable
water and sanitation by 2030. Poor water quality and bad sanitation are deadly; some five

28
million deaths a year are caused by water-related diseases. The World Health
Organization estimates that safe water could prevent 1.4 million child deaths
from diarrhoea each year (Wada et al., 2022).

In developing countries, 90% of all municipal will betewater still goes untreated into
local rivers and streams. Some 50 countries, with roughly a third of the world's
population, also suffer from medium or high water scarcity and 17 of these extract more
water annually than is recharged through their natural water cycles.[96] The strain not
only affects surface freshwater bodies like rivers and lakes, but it also degrades
groundwater resources (Jammi, 2018).

2.14.2 Human uses

2.14.2.1 Agriculture

The most substantial human use of water is for agriculture, including irrigated
agriculture, which accounts for as much as 80 to 90 percent of total human water
consumption. In the United States, 42% of freshwater withdrawn for use is for irrigation,
but the vast majority of water "consumed" (used and not returned to the environment)
goes to agriculture (Jammi, 2018).

Access to fresh water is often taken for granted, especially in developed countries that
have built sophisticated water systems for collecting, purifying, and delivering water, and
removing will betewater. But growing economic, demographic, and climatic pressures
are increasing concerns about water issues, leading to increasing competition for fixed
water resources, giving rise to the concept of peak water. As populations and economies
continue to grow, consumption of water-thirsty meat expands, and new demands rise for
biofuels or new water-intensive industries, new water challenges are likely (Sharad and
Vijay, 2020).

An assessment of water management in agriculture will be conducted in 2007 by

the International Water Management Institute in Sri Lanka to see if the world had
sufficient water to provide food for its growing population. It assessed the current
availability of water for agriculture on a global scale and mapped out locations suffering
from water scarcity. It found that a fifth of the world's people, more than 1.2 billion, live
in areas of physical water scarcity, where there is not enough water to meet all demands
(Gleick, 2021).

29
A further 1.6 billion people live in areas experiencing economic water scarcity, where the
lack of investment in water or insufficient human capacity make it impossible for
authorities to satisfy the demand for water. The report found that it would be possible to
produce the food required in the future, but that continuation of today's food production
and environmental trends would lead to crises in many parts of the world. To avoid a
global water crisis, farmers will have to strive to increase productivity to meet growing
demands for food, while industries and cities find ways to use water more efficiently
(Wada et al., 2022).

Water scarcity is also caused by production of water intensive products. For

example, cotton: 1 kg of cotton—equivalent of a pair of jeans—requires 10.9 cubic
meters (380 cu ft) water to produce. While cotton accounts for 2.4% of world water use,
the water is consumed in regions that are already at a risk of water shortage. Significant
environmental damage has been caused: for example, the diversion of water by the
former Soviet Union from the Amu Darya and Syr Darya rivers to produce cotton will be
largely responsible for the disappearance of the Aral Sea (Fine and Millero, 2021).

2.14.2.2 As a scientific standard

On 7 April 1795, the gram will be defined in France to be equal to "the absolute weight
of a volume of pure water equal to a cube of one-hundredth of a meter, and at the
temperature of melting ice". For practical purposes though, a metallic reference standard
will be required, one thousand times more massive, the kilogram. Work will be therefore
commissioned to determine precisely the mass of one liter of water. In spite of the fact
that the decreed definition of the gram specified water at 0 °C (32 °F)—a highly
reproducible temperature—the scientists chose to redefine the standard and to perform
their measurements at the temperature of highest water density, which will be measured
at the time as 4 °C (39 °F) (Jammi, 2018).

The Kelvin temperature scale of the SI system will be based on the triple point of water,
defined as exactly 273.16 K (0.01 °C; 32.02 °F), but as of May 2019 is based on
the Boltzmann constant instead. The scale is an absolute temperature scale with the same
increment as the Celsius temperature scale, which will be originally defined according to
the boiling point (set to 100 °C (212 °F)) and melting point (set to 0 °C (32 °F)) of water
(Hobbins, 2023).

30
Natural water consists mainly of the isotopes hydrogen-1 and oxygen-16, but there is also
a small quantity of heavier isotopes oxygen-18, oxygen-17, and hydrogen-2 (deuterium).
The percentage of the heavier isotopes is very small, but it still affects the properties of
water. Water from rivers and lakes tends to contain less heavy isotopes than seawater.
Therefore, standard water is defined in the Vienna Standard Mean Ocean
Water specification (Sharad and Vijay, 2020).

2.14.2.3 For drinking

The human body contains from 55% to 78% water, depending on body size. To function
properly, the body requires between one and seven liters (0.22 and 1.54 imp gal; 0.26 and
1.85 U.S. gal) of water per day to avoid dehydration; the precise amount depends on the
level of activity, temperature, humidity, and other factors (Wada et al., 2022).

Most of this is ingested through foods or beverages other than drinking straight water. It
is not clear how much water intake is needed by healthy people, though the British
Dietetic Association advises that 2.5 liters of total water daily is the minimum to maintain
proper hydration, including 1.8 liters (6 to 7 glasses) obtained directly from beverages.
Medical literature favors a lower consumption, typically 1 liter of water for an average
male, excluding extra requirements due to fluid loss from exercise or warm weather
(Gleick, 2021).

Healthy kidneys can excrete 0.8 to 1 liter of water per hour, but stress such as exercise
can reduce this amount. People can drink far more water than necessary while exercising,
putting them at risk of water intoxication (hyperhydration), which can be fatal. The
popular claim that "a person should consume eight glasses of water per day" seems to
have no real basis in science. Studies have shown that extra water intake, especially up to
500 milliliters (18 imp fl oz; 17 U.S. fl oz) at mealtime, will be associated with weight
loss. Adequate fluid intake is helpful in preventing constipation (Fine and Millero, 2021).

An original recommendation for water intake in 1945 by the Food and Nutrition Board of
the U.S. National Research Council read: "An ordinary standard for diverse persons is 1
milliliter for each calorie of food. Most of this quantity is contained in prepared
foods." The latest dietary reference intake report by the U.S. National Research Council
in general recommended, based on the median total water intake from US survey data
(including food sources): 3.7 liters (0.81 imp gal; 0.98 U.S. gal) for men and 2.7 liters

31
(0.59 imp gal; 0.71 U.S. gal) of water total for women, noting that water contained in
food provided approximately 19% of total water intake in the survey (Jammi, 2018).

Specifically, pregnant and breastfeeding women need additional fluids to stay hydrated.
The US Institute of Medicine recommends that, on average, men consume 3 liters
(0.66 imp gal; 0.79 U.S. gal) and women 2.2 liters (0.48 imp gal; 0.58 U.S. gal); pregnant
women should increase intake to 2.4 liters (0.53 imp gal; 0.63 U.S. gal) and breastfeeding
women should get 3 liters (12 cups), since an especially large amount of fluid is lost
during nursing (Hobbins, 2023).

Also noted is that normally, about 20% of water intake comes from food, while the rest
comes from drinking water and beverages (caffeinated included). Water is excreted from
the body in multiple forms; through urine and feces, through sweating, and by exhalation
of water vapor in the breath. With physical exertion and heat exposure, water loss will
increase and daily fluid needs may increase as well (Sharad and Vijay, 2020).

Humans require water with few impurities. Common impurities include metal salts and
oxides, including copper, iron, calcium and lead and harmful bacteria, such as Vibrio.
Some solutes are acceptable and even desirable for taste enhancement and to provide
needed electrolytes.The single largest (by volume) freshwater resource suitable for
drinking is Lake Baikal in Siberia (Gleick, 2021).

2.14.2.4 Will behing

Will behing is a method of cleaning, usually with water and soap or detergent. will
behing and then rinsing both body and clothing is an essential part of good hygiene and
health. Often people use soaps and detergents to assist in the emulsification of oils and
dirt particles so they can be will behed away. The soap can be applied directly, or with
the aid of a will behcloth (Wada et al., 2022).

People will be themselves, or bathe periodically for religious ritual or therapeutic

purposes or as a recreational activity. In Europe, some people use a bidet to will beh their
external genitalia and the anal region after using the toilet, instead of using toilet
paper. The bidet is common in predominantly Catholic countries where water is
considered essential for anal cleansing (Jammi, 2018).

More frequent is will behing of just the hands, e.g. before and after preparing food and
eating, after using the toilet, after handling something dirty, etc. Hand will behing is
important in reducing the spread of germs. Also common is will behing the face, which is

32
done after waking up, or to keep oneself cool during the day. Brushing one's teeth is also
essential for hygiene and is a part of will behing (Fine and Millero, 2021).

'will behing' can also refer to the will behing of clothing or other cloth items, like
bedsheets, whether by hand or with a will behing machine. It can also refer to will behing
one's car, by lathering the exterior with car soap, then rinsing it off with a hose, or will
behing cookware. will behing may damage the hair, causing dandruff, or cause rough
skin/skin lesions (Hobbins,2023).

2.14.2.5 Transportation

Maritime transport (or ocean transport) or more generally waterborne transport, is

the transport of people (passengers) or goods (cargo) via waterways. Freight transport by
sea has been widely used throughout recorded history. The advent of aviation has
diminished the importance of sea travel for passengers, though it is still popular for short
trips and pleasure cruises. Transport by water is cheaper than transport by air or
ground but significantly slower for longer distances. Maritime transport accounts for
roughly 80% of international trade, according to UNCTAD in 2020 (Sharad and Vijay,
2020).

Maritime transport can be realized over any distance by boat, ship, sailboat or barge, over
oceans and lakes, through canals or along rivers. Shipping may be
for commerce, recreation, or military purposes. While extensive inland shipping is less
critical today, the major waterways of the world including many canals are still very
important and are integral parts of worldwide economies (Gleick, 2021).

Particularly, especially any material can be moved by water; however, water transport
becomes impractical when material delivery is time-critical such as various types of
perishable produce. Still, water transport is highly cost effective with regular schedulable
cargoes, such as trans-oceanic shipping of consumer products – and especially for heavy
loads or bulk cargos, such as coal, coke, ores, or grains. Arguably, the industrial
revolution had its first impacts where cheap water transport by canal, navigations,
or shipping by all types of watercraft on natural waterways supported cost-effective bulk
transport (Wada et al., 2022).

Containerization revolutionized maritime transport starting in the 1970s. "General cargo"

includes goods packaged in boxes, cases, pallets, and barrels. When a cargo is carried in
more than one mode, it is intermodal or co-modal(Fine and Millero, 2021).

33
2.14.2.6 Chemical uses

Water is widely used in chemical reactions as a solvent or reactant and less commonly as
a solute or catalyst. In inorganic reactions, water is a common solvent, dissolving many
ionic compounds, as well as other polar compounds such as ammonia and compounds
closely related to water. In organic reactions, it is not usually used as a reaction solvent,
because it does not dissolve the reactants well and is amphoteric (acidic and basic)
and nucleophilic. Nevertheless, these properties are sometimes desirable. Also,
acceleration of Diels-Alder reactions by water has been observed. Supercritical water has
recently been a topic of research. Oxygen-saturated supercritical water combusts organic
pollutants efficiently (Jammi, 2018).

2.14.2.7 Heat exchange

Water and steam are a common fluid used for heat exchange, due to its availability and
high heat capacity, both for cooling and heating. Cool water may even be naturally
available from a lake or the sea. It is especially effective to transport heat
through vaporization and condensation of water because of its large latent heat of
vaporization (Sharad and Vijay, 2020).

A disadvantage is that metals commonly found in industries such as steel and copper
are oxidized faster by untreated water and steam. In almost all thermal power stations,
water is used as the working fluid (used in a closed-loop between boiler, steam turbine,
and condenser), and the coolant (used to exchange the will bete heat to a water body or
carry it away by evaporation in a cooling tower). In the United States, cooling power
plants is the largest use of water (Hobbins, 2023).

In the nuclear power industry, water can also be used as a neutron moderator. In
most nuclear reactors, water is both a coolant and a moderator. This provides something
of a passive safety measure, as removing the water from the reactor also slows the
nuclear reaction down. However other methods are favored for stopping a reaction and it
is preferred to keep the nuclear core covered with water so as to ensure adequate cooling
(Wada et al., 2022).

2.14.2.8 Fire considerations

Water has a high heat of vaporization and is relatively inert, which makes it a good fire
extinguishing fluid. The evaporation of water carries heat away from the fire. It is

34
dangerous to use water on fires involving oils and organic solvents because many organic
materials float on water and the water tends to spread the burning liquid (Clasen, 2020).

Use of water in fire fighting should also take into account the hazards of a steam
explosion, which may occur when water is used on very hot fires in confined spaces, and
of a hydrogen explosion, when substances which react with water, such as certain metals
or hot carbon such as coal, charcoal, or coke graphite, decompose the water,
producing water gas (Clasen, 2020).

The power of such explosions will be seen in the Chernobyl disaster, although the water
involved in this case did not come from fire-fighting but from the reactor's own water
cooling system. A steam explosion occurred when the extreme overheating of the core
caused water to flash into steam. A hydrogen explosion may have occurred as a result of
a reaction between steam and hot zirconium (Gleick, 2021).

Some metallic oxides, most notably those of alkali metals and alkaline earth metals,
produce so much heat on reaction with water that a fire hazard can develop. The alkaline
earth oxide quicklime is a mass-produced substance that is often transported in paper
bags. If these are soaked through, they may ignite as their contents react with water
(Sharad and Vijay, 2020).

2.14.2.9 Recreation

Humans use water for many recreational purposes, as well as for exercising and for
sports. Some of these include swimming, waterskiing, boating, surfing and diving. In
addition, some sports, like ice hockey and ice skating, are played on ice. Lakesides,
beaches and water parks are popular places for people to go to relax and enjoy recreation
(Fine and Millero, 2021).

Many find the sound and appearance of flowing water to be calming, and fountains and
other flowing water structures are popular decorations. Some keep fish and other flora
and fauna inside aquariums or ponds for show, fun, and companionship. Humans also use
water for snow sports such as skiing, sledding, snowmobiling or snowboarding, which
the require the water to be at a low temperature either as ice or crystallized into snow
(Jammi, 2018).

35
2.14.2.10 Water industry

The water industry provides drinking water and will betewater services
(including sewage treatment) to households and industry. Water supply facilities
include water wells, cisterns for rainwater harvesting, water supply networks, and water
purification facilities, water tanks, water towers, water pipes including
old aqueducts. Atmospheric water generators are in development (Wada et al., 2022).

Drinking water is often collected at springs, extracted from artificial borings (wells) in
the ground, or pumped from lakes and rivers. Building more wells in adequate places is
thus a possible way to produce more water, assuming the aquifers can supply an adequate
flow. Other water sources include rainwater collection. Water may require purification
for human consumption. This may involve the removal of undissolved substances,
dissolved substances and harmful microbes. Popular methods are filtering with sand
which only removes undissolved material, while chlorination and boiling kill harmful
microbes. Distillation does all three functions. More advanced techniques exist, such
as reverse osmosis. Desalination of abundant seawater is a more expensive solution used
in coastal arid climates (Hobbins, 2023).

The distribution of drinking water is done through municipal water systems, tanker
delivery or as bottled water. Governments in many countries have programs to distribute
water to the needy at no charge (Fine and Millero, 2021).

Reducing usage by using drinking (potable) water only for human consumption is
another option. In some cities such as Hong Kong, seawater is extensively used for
flushing toilets citywide in order to conserve freshwater resources (Wada et al., 2022).

Polluting water may be the biggest single misuse of water; to the extent that a pollutant
limits other uses of the water, it becomes a will bete of the resource, regardless of
benefits to the polluter. Like other types of pollution, this does not enter standard
accounting of market costs, being conceived as externalities for which the market cannot
account (Jammi, 2018).

Thus other people pay the price of water pollution, while the private firms' profits are not
redistributed to the local population, victims of this pollution. Pharmaceuticals consumed
by humans often end up in the waterways and can have detrimental effects on aquatic life
if they bioaccumulate and if they are not biodegradable (Gleick, 2021).

36
 CHAPTER THREE

MATERIALS AND METHODS

3.1 Study Area

The present study was conducted in Unguwar Jeji village, Kalgo Local Government,
Kebbi State. It has an area of 1,173 km2 and a population of 85,403 at the 2006 census,
the postal code of the area is 862, Latitude / Longitude : 12° 17' 1" N / 4° 6' 3" E
(NIPOST, 2009). The area is characterized by high temperature and it has an annual
rainfall which begins between April and September. The soils of these areas are sandy,
welled drained and formed in sandy loam.
3.2 Source of Water Sample
A total of five potable water samples from the randomly selected place at Unguwar Jeji
village were collected in plastic containers which have been sterilized with 10% methanol
solution. The samples were assigned codes; A1to A5. The samples were carried into the
laboratory and stored in a refrigerator at 4ºC prior to analysis.
3.3 Materials and Reagents
Materials to be used for this analysis were standard microbiological materials and were
gotten from the microbiology laboratory except the water samples. Using; Nutrient agar,
Sabroud dextrose agar, incubator, microscope, weighing balance, autoclave, biosafety
cabinet, distilled water, Wire loop, cotton wool, normal saline, Aluminum foil, Swab
stick, masking tape, test-tubes, test-tube rack, disposable petri-dishes, conical flask,
measuring cylinder, pipette tips, micropipette, Spirit lamp, permanent marker, glass slide.
Crystal violet, Lugos Iodine, Acetone, Safranin Red, Hydrogen Peroxide, Plasma,
Ethanol, Antiseptics and Lactophenol cotton blue solution.
3.4 Media preparation
3.4.1 Nutrient Agar
This was prepared according to the illustration of the manufacturer. The nutrient agar
powder 28g was weighed and dissolved in 1000ml of distilled water in a conical flask.
The mouth of the flask was plugged with cotton wool and wrapped with aluminum foil
and the mixture was sterilized at 121 0C for 15 minutes in an autoclave. After autoclaving,
the mixture was allowed to cool to a temperature of 47 0C and aseptically dispense in to a
petridish (Oyeleke and Manga, 2008).

37
3.4.2 Sabouraud Dextrose Agar
Suspend 65 g of the medium in one liter of distilled water. Then heat with frequent
agitation and boil for one minute to completely dissolve the medium. This is autoclaved
at 121° C for 15 minutes. It was then cool to 45 to 50°C and pour into petri dishes or
tubes for slants preparation (Muños et al., 2011).
3.5 Serial Dilution
Five series (10-1 – 10-5) sterile test tube containing 9ml of distilled water was used to
reduce microbial load for easy isolation of the sample. 1ml from stock solution will be
withdrawn and dispense into test tube labeled 10-1 shake and withdraw 1ml from 10-1 and
dispensed into test tube labeled 10 -2, this continued up to the last tube labeled 10 -5 in
series. The serial dilution of 10 different samples will be carried out accordingly, by
which five (5) tests tube used for each sample containing 9ml of distilled water to reduce
the load of bacteria for easy isolation. Samples were independently poured onto a set of
culture media namely nutrient agar. Plates were incubated for 24hrs at 37 oC in the
presence or not of an atmosphere of 5% CO2.
3.6 Bacteria culture
An aliquot of 0.1ml from each dilution (tubes 10 -2 and 10-4) was aseptically transferred to
the center of sterile Petri-dishes in duplicates. Then sterile molten nutrient agar at about
450C were poured on sterile petridish for bacteria. These was mixed by a combination of
rotational movement: To and fro, clockwise and anticlockwise direction for 5-10 seconds.
The plates were allowed on the bench to solidify, inverted and properly labeled. These
were incubated at 300C at 24 days.
3.7 Subculture of Bacterial Isolates
Colonies from the primary plates were aseptically picked with a sterile wire loop and
transferred onto freshly prepared sterile nutrient agar plate, with a streaking technique
such that discrete colonies appear at the ends of streaked lines after incubation. The
subculture plates were incubated at 37°C for 24 hours to 48 hours.
3.8 Subculture of Fungal Isolates
Colonies from the primary plates were aseptically picked with a sterile inoculation needle
and transferred onto a freshly prepared sterile Sabouraud Dextrose Agar (SDA) plate
with a streaking method and incubated for 3- 5 days at room temperature. Pure colonies
were stored in the refrigerator at 10°C-15°C until needed for characterization and
identification.

38
3.9 Characterization and Identification of Bacterial Isolates
All bacterial isolates was characterized and identified based on their cultural,
morphological, microscopic examination and biochemical characteristics following the
methods prescribed by (Cheesbrough, 2005). Biochemical test conducted include the
following: Gram stain, Catalase test, Oxidase test, Citrate, Triple Sugar Iron (TSI),
Eosine Methylene Blue (EMB) Test, Mannitol Salt Agar (MSA), Motility, Indole and
Urease test (MIU).
Eosine Methylene Blue (EMB)
Eosin-methylene blue (EMB) agar is selective for gram-negative bacteria against gram-
positive bacteria. In addition, EMB agar is useful in isolation and differentiation of the
various gram-negative bacilli and enteric bacilli, generally known as coliforms and fecal
coliforms respectively.
About 35.96 grams was suspend in 1000 ml distilled water. Mix until the suspension is
uniform. Heat to boiling to dissolve the medium completely. Then it was Sterilize by
autoclaving at 15 lbs pressure (121°C) for 15 minutes. Cool to 45-50°C and shake the
medium in order to oxidize the methylene blue (i.e. to restore its blue color) and to
suspend the flocculent precipitate. Then it was Pour into sterile Petri plates. Allow plates
to warm to room temperature. The agar surface should be dry before inoculating. Then it
will be Inoculate and streak the specimen as soon as possible after collection. If the
specimen to be cultured is on a swab, roll the swab over a small area of the agar surface
and streak for isolation with a sterile loop. Incubate plates aerobically at 35-37°C for 18-
24 hours and protect from light. Examine plates for colonial morphology. If negative
after 24 hours, reincubate an additional 24 hours.
Mannitol Salt Agar (MSA)
Mannitol salt agar or MSA is a commonly used selective and differential growth
medium in microbiology. It encourages the growth of a group of certain bacteria while
inhibiting the growth of others. It contains a high concentration (about 7.5–10%)
of salt (NaCl) which is inhibitory to most bacteria - making MSA selective against most
Gram-negative and selective for some Gram-positive bacteria
(Staphylococcus, Enterococcus and Micrococcaceae) that tolerate high salt
concentrations.
About 111 grams of Mannitol Salt Agar was suspended in 1000 ml of distilled water.
Then it will be boil to dissolve the medium completely. Sterilize by autoclaving at 15 lbs.

39
pressure (121°C) for 15 minutes. If desired, sterile Egg Yolk Emulsion (E7899) can be
added to a final concentration of 5% v/v after autoclaving. Then it was pour cooled
Mannitol Salt Agar into sterile petri dishes and allow to cool to room temperature.
3.9.1 Gram Staining
Gram stain or gram staining, also called Gram’s Method, is a method of staining used to
distinguish and classify bacterial species into two large groups; gram positive bacteria
and gram negative bacteria. The smear was covered with crystal violet stain for 30 to 60
seconds. It was then rinse with clean water. The smear was covered with Lugo’s Iodine
for 30 to 60 seconds. It was rinse with clean water. Decolorizer (95% ethanol) was
applied rapidly (few seconds) and was clean immediately with clean water. Finally the
smear will be covered with safranin stain for 60 seconds and was behed with clean water
and allowed to air dry. The slide was mounted on the microscope and observed x100 oil
immersion objective lens (Quinn et al., 2003).
3.9.2 Biochemical Tests
3.9.2.1 Oxidase Test
Oxidase test is a test in used in microbiology to determine whether a bacterium
procedures certain cytochrome C oxidases. A small portion of isolate was picked by the
use of sterile wire loop and smeared on the wetted portion of filter paper with a few drop
of 1% oxidase reagent solution (tetra methyl-p-phenylenediamine dihydrochloride). Fresh
culture of the isolate was then emulsify on the filter paper and observed. The
development of an intense purple colour within 30 sec indicated negative test and oxidase
positive organism give blue colour within 5 – 10 seconds.
3.9.2.2 Catalase test
Catalase test is a biochemical test for aerobic organisms that detects the production of
catalase enzyme in the organism. A small amount of isolate was picked by the use of wire
loop and transferred into a clean glass slide and a drop of 3% hydrogen peroxide solution
H2O2 was placed on a clean, grease-free glass slide; the slide by using a dropper or
Pasteur pippete and it was mixed. A rapid evolution of oxygen within 10sec is evidenced
by bubbling indicates positive result and a negative result is no bubbles or only a few
scattered bubbles.
3.9.2.2 Indole Test
The test will be carried out as described by (Oyeleke and Manga, 2008). The organism
was grown in 5ml of 24hrs. After 24hrs of incubation, kovac’s indole reagent was added,
3-8 drop of reagent are usually sufficient. It will be then shake gentle. A positive reaction

40
indicated by development of red colour in the reagent layer above the broth within 1
minute, and in a negative reaction, the reagent retains its yellow colour.
3.9.2.5 Citrate Test
The test was carried out as described by (Oyeleke and Manga, 2008). A speak of each
isolate will be inoculated into simmons citrate medium and incubated at 37°C for 24-
72hrs. A positive citrate test indicates the formation of blue colour while the initial
yellow colour indicate negative.
3.9.2.6 Urease Test
The test was carried out as described by (Oyeleke and Manga, 2008). A speak of each
isolate was inoculated into indole motility and urea agar and incubated at 37°C for 24-
72hrs. The liberation of red colour indicate urease positive test while initial yellow colour
indicate negative.
3.9.2.7 Motility Test
This was done as described by Vermeiren et al. (2004). A little portion of each isolate was
stabbed onto indole motility and urea agar and incubated at 370C for 24 hours. Motility
was observed by spread of the organism outwards from the stabled area.
3.9.3.9 Triple Sugar Iron Agar (TSI)
The test was done by obtaining the materials to be cultured from the solid medium or a
broth culture with sterile needle. The surface of slant was streak and the butt was stabbed
2-3 times. The cap was loosely close and incubates at 35°C for 24hrs. It is important that
the cap is not screw tight and the reaction will be read after 24hrs of incubation. TSI
glucose fermenter indicated by the butt becoming yellow, if no sugar is fermented, the
culture was grown using peptone present in the medium but no yellow coloration of the
butt or slant would occur (Oyeleke and Manga, 2008).
3.9.3 Identification of Fungal Isolate
The complete identification of fungi isolate was done by comparing the result of their
morphological characteristics with those of known taxa.
3.9.3.1Slide Culture Technique
A fragment of the aerial mycelia was picked with a sterile inoculating needle and
inoculated on the slide containing prepared Sabouraud Dextrose Agar. The slide was
incubated at room temperature for twenty four hours after which it will be examined
under the microscope.
3.9.3.2 Microscopic Examination
Lactophenol cotton blue solution was used. Add a drop of the solution and place on a

41
clean grease-free slide. A fragment of the mould was emulsified in the solution after
which the slide is covered with a cover slip, avoiding bubbles. The slide was thereafter
viewed under the microscope.

42
 CHAPTER FOUR

4.0 RESULTS

From the research conducted, a total number of twenty bacterial belonging to six genera
were isolated and twelve isolate belonging to two (2) genera of fungi were isolated. This
were isolated from five (5) different samples of portable drinking water in Unguwar Jeji
village, kalgo, Kebbi state. Table 4.1 and 4.2 indicated biochemical test of the bacterial
isolate and fungi isolate respectively. The organism isolated involve bacteria such as
Corynebacterium renale, Lactobacillus delbruicii, Lactobacillus casei, Staphlococcus
aureus, C.Murium while the fungi isolated include Aspergillus flavus, Aspergillus niger,
Aspergillus fumigates, Neosa morua fischeri.

It was also discovered in table 4.2 that the fungi isolates were found to only belongs to
two genera and the species includes Aspergillus spp and Nosea morua fischeri,

43
 Table 4.1 Biochemical test of bacteria isolate

Organism

Reaction

Catalase

Motility

Oxidase
Glucose
Monitol

Lactose
Sample

Citrate
Urease
Indole
Gram

Slope
S/No

Butt

Gas
H 2S
1 PV10-21 +Rod + + + - Non Y Y - - - + + Corynebacterium
bacilli Motile renale
-2
PV10 2 +Bacilli + + + - Motile Y R - - - + - C. murium
PV10-41 +Bacilli + + + - Motile Y Y - - - + + Corynebacterium
renale
-4
PV10 2 +Rod - - + - - Motile Y R - - - + - ,
bacilli
-2
ADV10 1 +Bacilli - - + - + Motile Y Y - - - + + Lactobacillus casei
ADV10-22 +Rod + + + - Motile Y R - - - + - C. murium
ADV10-41 +Bacilli - + + - Motile Y R - - - + - Staphylococcus sp
-4
ADV10 2 +Bacilli + + + - Motile Y R - - - + - C. murium
HNF10-21 +Rod - + + + Non Y R - - - + - C. murium
Motile
-2
10. HNF10 2 +Cocci - + + - + Motile Y Y - - - + + Staphylococcus
cluster aureus
-4
11. HNF10 1 +Cocci - + + - Motile Y R - - - + - Staphylococcus
aureus
12. HNF10-42 +Cocci + - + - Motile Y R - - - + - Staphylococcus
aureus
13. JM10-21 +SR - - + - Non Y R - - - + - Lactobacillus
Motile delbruicii
-2
14. JM10 2 +Bacilli - - + - Motile Y R - - - + - Lactobacillus
delbruicii
-4
15. JM10 1 +Bacilli - - + - Non Y R - - - + - Lactobacillus
Motile delbruicii
16. JM10-42 +Cocci + - + - + Motile Y R - - - + - Staphylococcus
aureus
-2
17. AMH10 1 Cocci - + + - Motile Y R - - - + - Staphylococcus sp
18. AMH10-22 +Cocci - + + - + Non Y R - - - + - Staphlococcus
Motile aureus
-4
19. AMH10 1 +Bacilli + + + - Non Y R - - - + + C. murium
Motile
-4
20. AMH10 2 +Cocci - + + - - Motile Y R - - - + - Staphylococcus sp

44
 Table 4.2 Fungi isolates of portable drinking water

S/ Sample Fungi Isolation

No
1. ADV 10-2 Aspergillus flavus
2. ADV 10-4 Aspergillus flavus, Aspergillus niger, Aspwegillus fumigatus
3. AMH 10-2 Aspergillus niger
4. AMH 10-4 Aspergillus flavus
5. JM 10-2 Neosa morua fischeri
6. JM 10-4 Aspergillus niger
7. HNF 10-2 Aspergillus niger, Aspergillus fumigatus
8. HNF 10-4 Aspergillus flavus, Aspergillus niger
9. PV 10-2 Aspergillus niger
10. PV 10-4 Aspergillus niger

45
 CHAPTER FIVE

DISCUSSION, RECOMMENDATION AND CONCLUSION

5.1 DISCUSSION

This study determined the safety status of selected portable drinking water in Unguwar
Jeji village metropolis, Kalgo, Kebbi State, Nigeria with regard to some microbial loads.
Table 4.1 shows the biochemical test of the bacterial isolate from the water samples
where as it revealed a total number of six (6) species of bacteria which include
Corynebacterium renale, C. murium, Lactobacillus delbruicii, Lactobacillus casei,
Candida spp and Staphlococcus aureus. This is in agreement with the study of
Obunukwu et al. (2018). and Abhinaba Ghosh, (2019). Mohammed and Kuhiyep, (2020)
and Samuel, (2022).
Corynebacterium renale, C. cystitidis, and C. pilosum are sometimes referred to as the ‘C.
renale group.’ These are piliated and non-motile gram-positive rods and are distinguished
biochemically (Arkoet al., 2019). C. renale causes pyelonephritis in cattle, and C.
pilosum and C. cystitis cause posthitis, also known as pizzle rot or sheath rot, in sheep
and goats. The bacteria are ubiquitous in the environment and inhabit the vagina
and prepuce. High-protein diets, resulting in higher urea excretion, more basic urine, and
irritation of the preputial and vaginal mucous membranes are contributing factors (Arko
et al., 2019).
The current study revealed two probiotic bacteria found in the water sample which
include Lactobacillus delbrueckii and Lactobacillus casei. Lactobacillus delbrueckii is a
species of bacteria that is marketed as a probiotic. ("good" bacteria)."Good" bacteria such as
L. delbrueckii might help the body break down food, absorb nutrients, and fight off "bad"
organisms that might cause diseases. These bacteria are sometimes added to fermented foods
like yogurt and also found in dietary supplements (Patterson and Lima, 2015). Lactobacillus
casei (L. casei) is a type of probiotic ("good" bacteria) found in the infant digestive tract. It
produces lactic acid in the gut. It can help break down food, absorb nutrients, and fight off
"bad" organisms that might cause diseases. L. casei is sometimes added to fermented foods
like yogurt and is also found in probiotic supplements (Patterson and Lima, 2015)
Candida can cause infections if it grows out of control or if it enters deep into the body.
For example, it can cause infections in the bloodstream or internal organs like the kidney,
heart, or brain. Learn more about how Candida develops antimicrobial resistance and

46
causes illness. S. aureus has long been recognized as one of the most important bacteria
that cause disease in humans. It is the leading cause of skin and soft tissue infections such
as abscesses (boils), furuncles, and cellulitis (Raikwaret al., 2018).
Table 4.2 shows the results of fungal isolate found in the portable drinking water in
Unguwar Jeji village, the results reveal the presence of Aspagillus flavus, Aspagillus
niger, Aspagillus fumigatus, and Neosa morua fischeri and This study is in corolation
with the study of Obunukwu et al. (2018). Aspergillus infections have grown in
importance in the last years. However, most of the studies have focused on Aspergillus
fumigatus, the most prevalent species in the genus. In certain locales and hospitals,
Aspergillus flavus is more common in air than A. fumigatus, for unclear reasons
(Thompson and Khan, 2019).
After A. fumigatus, A. flavus is the second leading cause of invasive aspergillosis and it is
the most common cause of superficial infection. Experimental invasive infections in mice
show A. flavus to be 100-fold more virulent than A. fumigatus in terms of inoculum
required. Particularly common clinical syndromes associated with A. flavus include
chronic granulomatous sinusitis, keratitis, cutaneous aspergillosis, wound infections and
osteomyelitis following trauma and inoculation. Outbreaks associated with A. flavus
appear to be associated with single or closely related strains, in contrast to those
associated with A. fumigatus. In addition, A. flavus produces aflatoxins, the most toxic
and potent hepatocarcinogenic natural compounds ever characterized (Thompson and
Khan, 2019).

47
5.2 CONCLUSION

From the results of this study, it can be concluded that the portable drinking water supply
from the majority of the sampled areas were contaminated with bacteria and fungi.
Equally, Aspergillus species are the majority fungi found in the water samples while
Lactobacillus delbruicii bacteria found to be majority followed by Staphylococcus aureus
and C.murium. Therefore, awareness on the possible risks associated with consuming
water contaminated with microbes should be given to rural communities where such is
the drinking water in the area.

5.3 RECOMMENDATIONS
To prevent any outbreak of diseases, water containers especially the overhead tanks
should be thoroughly washed with clean water and disinfectant before use. However, the
Municipal Assembly (Town Council) should be educated on possible means of treating
of water such as boiling, use of chlorination tablets and use of water filters so as to
prevent possible adverse health effects.

48
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