1. science
2. ecology
3. pollution

•Water is a ubiquitous chemical substance that is composed of hydrogen and oxygen and
is vital for all known forms of life.
•In typical usage, water refers only to its liquid form or state, but the substance also has a
solid state, ice, and a gaseous state, water vapor or steam. Water covers 71% of the Earth's
surface. On Earth, it is found mostly in oceans and other large water bodies, with 1.6% of
water below ground in aquifers and 0.001% in the air as vapor, clouds (formed of solid and
liquid water particles suspended in air), and precipitation.Oceans hold 97% of surface
water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers, lakes
and ponds 0.6%.
•Water on Earth moves continually through a cycle of evaporation or transpiration
(evapotranspiration), precipitation, and runoff, usually reaching the sea. Over land,
evaporation and transpiration contribute to the precipitation over land.
•Clean, fresh drinking water is essential to human and other lifeforms. Access to safe
drinking water has improved steadily and substantially over the last decades in almost
every part of the world. However, some observers have estimated that by 2025 more than
half of the world population will be facing water-based vulnerability. A recent report
(November 2009) suggests that by 2030, in some developing regions of the world, water
demand will exceed supply by 50%.
 Water is the chemical substance with chemical formula H2O: one molecule of
water has two hydrogen atoms covalently bonded to a single oxygen atom.
Water appears in nature in all three common states of matter and may take many
different forms on Earth: water vapor and clouds in the sky; seawater and icebergs
in the polar oceans; glaciers and rivers in the mountains; and the liquid in aquifers
in the ground.
 The major chemical and physical properties of water are:
 Water is a tasteless, odorless liquid at standard temperature and pressure. The
color of water and ice is, intrinsically, a very light blue hue, although water appears
colorless in small quantities. Ice also appears colorless, and water vapor is
essentially invisible as a gas.
 Water is transparent, and thus aquatic plants can live within the water because
sunlight can reach them. Only strong UV light is slightly absorbed.
Water can dissolve many different substances,
giving it varying tastes and odors. Humans and
other animals have developed senses which (more
or less) enable them to evaluate the potability of
water by avoiding water that is too salty or putrid.
Humans also tend to prefer cold water to lukewarm
water since cold water is likely to contain fewer
microbes. The taste advertised in spring water or
mineral water derives from the minerals dissolved
in it: Pure H2O is tasteless and odorless. The
advertised purity of spring and mineral water refers
to absence of toxins, pollutants and microbes.
•Main articles: Hydrology and Water distribution on Earth
•A graphical distribution of the locations of water on Earth.
•Water covers 71% of the Earth's surface; the oceans contain 97.2% of the
Earth's water.
•The Antarctic ice sheet, which contains 90% of all fresh water on Earth, is
visible at the bottom. Condensed atmospheric water can be seen as
clouds, contributing to the Earth's albedo.
•Hydrology is the study of the movement, distribution, and quality of water
throughout the Earth. The study of the distribution of water is
hydrography. The study of the distribution and movement of groundwater
is hydrogeology, of glaciers is glaciology, of inland waters is limnology
and distribution of oceans is oceanography. Ecological processes with
hydrology are in focus of ecohydrology.

The sun, which drives the water cycle, heats water in the oceans. Some of it
evaporates as vapor into the air. Ice and snow can sublimate directly into water
vapor.

Rising air currents take the vapor up into the atmosphere, along with water from
evapotranspiration, which is water transpired from plants and evaporated from the
soil. The vapor rises into the air where cooler temperatures cause it to condense into
clouds.
.



Air currents move clouds around the globe, cloud particles collide, grow, and fall out
of the sky as precipitation. Some precipitation falls as snow and can accumulate as
ice caps and glaciers, which can store frozen water for thousands of years.
Snowpacks in warmer climates often thaw and melt when spring arrives, and the
melted water flows overland as snowmelt. Most precipitation falls back into the
oceans or onto land, where, due to gravity, the precipitation flows over the ground as
surface runoff.
A portion of runoff enters rivers in valleys in the landscape, with streamflow moving
water towards the oceans. Runoff, and ground-water seepage, accumulate and are
stored as freshwater in lakes.
WATER POLLUTION
 Water pollution is the contamination of water
bodies (e.g. lakes, rivers, oceans, groundwater).
 Water pollution affects plants and organisms living
in these bodies of water; and, in almost all cases
the effect is damaging either to individual species
and populations, but also to the natural biological
communities.
 Water pollution occurs when pollutants are
discharged directly or indirectly into water bodies
without adequate treatment to remove harmful
compounds.
SOURCES OF WATER POLLUTION.

1) INDUSTRY

Industry is a huge source of water pollution, it produces pollutants that are
extremely harmful to people and the environment.

Many industrial facilities use freshwater to carry away waste from the plant and
into rivers, lakes and oceans.

Pollutants from industrial sources include:
– Asbestos – This pollutant is a serious health hazard . Asbestos fibres can
be inhaled and cause illnesses such as asbestosis, lung cancer, intestinal
cancer and liver cancer.
– Lead – This is a metallic element and can cause health and environmental
problems. It is a non-biodegradable substance so is hard to clean up once
the environment is contaminated. Lead is harmful to the health of many
animals, including humans, as it can inhibit the action of bodily enzymes.
2) OIL POLLUTION IN WATER
 Oceans are polluted by oil on a daily basis from oil spills, routine
shipping, run-offs and dumping.
 Oil spills make up about 12% of the oil that enters the ocean. The rest
come from shipping travel, drains and dumping.
 An oil spill from a tanker is a severe problem because there is such a
huge quantity of oil being spilt into one place.
 Oil spills cause a very localised problem but can be catastrophic to
local marine wildlife such as fish, birds and sea otters.
 Oil cannot dissolve in water and forms a thick sludge in the water. This
suffocates fish, gets caught in the feathers of marine birds stopping
them from flying and blocks light from photosynthetic aquatic plants.
3) RADIO ACTIVE WASTE
 Nuclear waste is produced from industrial, medical and
scientific processes that use radioactive material. Nuclear
waste can have detrimental effects on marine habitats.
Nuclear waste comes from a number of sources:
 Operations conducted by nuclear power stations produce
radioactive waste. Nuclear-fuel reprocessing plants in
northern Europe are the biggest sources of man-made
nuclear waste in the surrounding ocean. Radioactive traces
from these plants have been found as far away as
Greenland.
 Mining and refining of uranium and thorium are also
causes of marine nuclear waste.
HARMS OF WATER POLLUTION
 Virtually all types of water pollution are harmful to the health of humans
and animals. Water pollution may not damage our health immediately but
can be harmful after long term exposure. Different forms of pollutants
affect the health of animals in different ways:
 Heavy metals from industrial processes can accumulate in nearby lakes
and rivers. These are toxic to marine life such as fish and shellfish, and
subsequently to the humans who eat them.
 Industrial waste often contains many toxic compounds that damage the
health of aquatic animals and those who eat them. Some of the toxins in
industrial waste may only have a mild effect whereas other can be fatal.
They can cause immune suppression, acute poisoning.
 Microbial pollutants from sewage often result in infectious diseases that
infect aquatic life and terrestrial life through drinking water. Microbial
water pollution is a major problem in the developing world, with diseases
such as cholera and typhoid fever being the primary cause of infant
mortality.
HARMS OF WATER POLLUTION
 Organic matter and nutrients causes an increase in aerobic
algae and depletes oxygen from the water column. This
causes the suffocation of fish and other aquatic organisms.
 Sulfate particles from acid rain can cause harm the health
of marine life in the rivers and lakes it contaminates, and
can result in mortality.
 Suspended particles in freshwater reduces the quality of
drinking water for humans and the aquatic environment for
marine life. Suspended particles can often reduce the
amount of sunlight penetrating the water, disrupting the
growth of photosynthetic plants and micro-organisms.
PREVENTIONS
 If you want to help keep our waters clean, there are many
things you can do to help. You can prevent water pollution
of nearby rivers and lakes as well as groundwater and
drinking water by following some simple guidelines in your
everyday life.
 Conserve water by turning off the tap when running water
is not necessary. This helps prevent water shortages and
reduces the amount f contaminated water that needs
treatment.
 Be careful about what you throw down your sink or toilet.
Don't throw paints, oils or other forms of litter down the
drain.
 Use environmentally household products, such as washing
powder, household cleaning agents and toiletries.
PREVENTIONS
 Take great care not to overuse pesticides and fertilisers.
This will prevent runoffs of the material into nearby water
sources.
 By having more plants in your garden you are preventing
fertiliser, pesticides and contaminated water from running
off into nearby water sources.
 Don't throw litter into rivers, lakes or oceans. Help clean up
any litter you see on beaches or in rivers and lakes, make
sure it is safe to collect the litter and put it in a nearby
dustbin.
MAKING OURSELVES SAFE
Water fit for human consumption is called drinking water or potable
water. Water that is not potable can be made potable by filtration or
distillation (heating it until it becomes water vapor, and then
capturing the vapor without any of the impurities it leaves behind),
or by other methods (chemical or heat treatment that kills bacteria).
Sometimes the term safe water is applied to potable water of a lower
quality threshold . Water that is not fit for drinking but is not harmful
for 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).
SCARCE OF DRINKING WATER
•This natural resource is becoming scarcer in certain places, and its
availability is a major social and economic concern. Currently, about a
billion people around the world routinely drink unhealthy water.
• Most countries accepted the goal of halving by 2015 the number of
people worldwide who do not have access to safe water and sanitation
during the 2003 G8 Evian summit. Even if this difficult goal is met, it will
still leave more than an estimated half a billion people without access to
safe drinking water and over a billion without access to adequate
sanitation.
• Poor water quality and bad sanitation are deadly; some five million
deaths a year are caused by polluted drinking water. The World Health
Organization estimates that safe water could prevent 1.4 million child
deaths from diarrhea each year.
•It is, rather, the distribution of potable and irrigation water which is
scarce, rather than the actual amount of it that exists on the earth.
 Sewage treatment, or domestic
wastewater treatment, is the process of
removing contaminants from wastewater
and household sewage, both runoff and
domestic. It includes physical, chemical,
and biological processes to remove
physical, chemical and biological
contaminants.
 Its objective is to produce a waste
stream (or treated effluent) and a solid
waste or sludge suitable for discharge
or reuse back into the environment. This
material is often inadvertently
contaminated with many toxic organic
and inorganic compounds.
•Sewage is created by residences, institutions, and commercial and
industrial establishments. Raw influent (sewage) includes household
waste liquid from toilets, baths, showers, kitchens, sinks, and so forth
that is disposed of via sewers.
• In many areas, sewage also includes liquid waste from industry and
commerce. A lot of sewage also includes some surface water from roofs
or hard-standing areas.
• Municipal wastewater therefore includes residential, commercial, and
industrial liquid waste discharges, and may include storm water runoff.
•Examples of treatment processes used for storm water include
sedimentation basins, wetlands, buried concrete vaults with various
kinds of filters, and vortex separators (to remove coarse solids
 Pre-treatment removes materials that
can be easily collected from the raw
wastewater before they damage or clog
the pumps and skimmers of primary
treatment clarifiers.
 In the primary sedimentation stage, sewage
flows through large tanks, commonly called
"primary clarifiers" or "primary sedimentation
tanks".

The tanks are large enough that sludge can
settle and floating material such as grease and
oils can rise to the surface and be skimmed off.
 The main purpose of the primary sedimentation
stage is to produce both a generally
homogeneous liquid capable of being treated
biologically and a sludge that can be separately
treated or processed.
 Secondary treatment is designed to substantially degrade the
biological content of the sewage which are derived from
human waste, food waste, soaps and detergent.
 The majority of municipal plants treat the settled sewage
liquor using aerobic biological processes. For this to be
effective, the biota require both oxygen and a substrate on
which to live.
 There are a number of ways in which this is done. In all these
methods, the bacteria and protozoa consume biodegradable
soluble organic contaminants (e.g. sugars, fats, organic
short-chain carbon molecules, etc.) and bind much of the
less soluble fractions into floc.
 There are many methods through which
the wastewater undergoes in the
secondary treatment in order to get
purified.the process include:






Activated sludge
Surface-aerated basins
Filter beds (oxidizing beds)
Biological aerated filters
Membrane bioreactors
Secondary sedimentation
Rotating biological contactors
Here is a video on sewage treatment
plant
There are lots of uses of
water. They are listed
below :
 Water is used for
drinking, washing ,
bathing , etc.
 Its also used for
irrigation purpose.
 A lot of water is used
to make food. Almost
every food contains
water
o Water is also used in
industry
o Water is used in dams
to manufacture hydroelectricity
o Its also used in vehicles
to make the
temperature of the
engine to cool down.
o Its also used in
construction work.
 Water can dissolve almost
everything in the world.
 The only things which water
can’t dissolve is desert
sand, oil, ghee and butter.
 Water can dissolve tea
leaves, coffee. Salt, sugar,
soil, mud, lemon, turmeric
powder, red chili powder,
etc,
There are lots of
river action plans
taken by the
government taken
to make the rivers
pollution less.
In the few slides
after this you will
see about the few
two India's river
action plans.
 An plan was setup to save
river Ganga.
 The plan was launched in
1985.
 It was aimed to reduce the
pollution levels in the
ganga.
 But, the increasing
population and
 industrialization have
already damaged
 this mighty river beyond
repair.
 This plan was setup
to save river
Yamuna.
 It was launched in
1993.
 It had a plan to
restore the river
yamuna to its past
glory.
 There were two
plans setup named
as YAP-I and YAP-II.
 Reuse of water whenever
possible, Kitchen water
can be used for watering
the plant.
 Plan your kitchen activity
to avoid wastage of fuel
and water.
 Plastic materials can be a
murder weapons for
wildlife, minimise their use.
Blown from land and
roadsides, they often end
up in the water, where they
can entangle and kill birds
and fishes.
• Take showers instead of baths.
Showers use less water - if you
limit them to five minutes. Install
low-flow shower-heads
• Use sprinkler for irrigation.
• Use scientific method of
application fertilizers. .
• Run your dishwasher, washing
machine, and dryer only when
you have full loads. · When
possible, use an outdoor
clothesline instead of a clothes
dryer.
• Fix leaks promptly. A dripping
joint can waste more than 76
liters of water a day. .
 Don't keep on the tap
running while having,
bath, brushing teeth, or
washing dishes it wastes
about 2 liters of water
every minute.
 Don’t hose down your
lawn or corridor to clean
it. Sweep it off.
 Don’t wash the clothes
and kitchen utensils in
the water bodies
 Don’t litter. When
camping, keep the areas
clean.
 Avoid throwing flowers,
sweets, puja materials
into a river. It will degrade
the quality of water. The
river wont be happy with
this.
 Avoid throwing dead
bodies in a river. This will
ultimately landing in the
mouth of dogs, vultures &
other animals.
 Never dump anything into
the water bodies.
 Avoid use of weedicides