2. What is recycling of water ?
Treatment of wastewater is actually a
remarkably simple process that utilizes
very basic physical, biological, and chemical
principles to remove contaminants from
water. Use of mechanical or physical
systems to treat wastewater is generally
referred to as primary treatment, and use
of biological processes to provide further
treatment is referred to as secondary
treatment. Advanced secondary treatment
usually involves applying chemical systems
in addition to biological ones, such as
injecting chlorine to disinfect the water
3. How is it done…?
recycling graywater can also be doncostbenefit analysis of a free, more laborintensive system versus an installed, more
expensive system is going to be a no-brainer:
a free or cheaper system is usually the way
to go. Many people who recycle their
graywater bootleg it anyway (especially in
California, where the legalities are so
complex that it makes it almost impossible
to recycle water for less than $5,000 or
$7,000).e at home
4. How is it utilised..?
Recycled water can be used for almost any use, as long
as it is treated to a level to make it fit for that
intended purpose (i.e. fit-for-purpose) from a health
and environmental perspective . However, the cost of
treatment may make reclamation uneconomical for
some uses. Australia now has more than 600 different
recycled water schemes operating. The bulk of these
schemes involve:
Urban and municipal environments
Households, golf courses and recreational parks.
Industry
Washing and cooling in power stations and mills.
6. What is energy…?
Energy is the capacity to do work and transfer heat. Work is performed
when an object or substance is moved over some distance. Energy is
needed to carry out processes, such as boiling water or burning candles.
Energy is also the heat that flows from a hot object or substance to a
cold one, when they come in contact. A clear example of this is the fact
that water heats up when you put in a water boiler device.
Energy has many forms, such as light, heat, electricity, chemical energy
(stored in chemical bonds) and mechanical energy (moving matter, such as
flowing water).
All energy forms are divided up between two main kinds of energy. The
first main kind of energy is kinetic energy, the energy of motion and
action. Heat is a total of kinetic energy of atoms, ions or molecules.
When these chemical compounds are in motion due to kinetic energy they
will warm up. You cannot always detect heat that originates from kinetic
energy, because sometimes the heat of a substance can rise without an
additional rise in temperature. The second main kind of energy is
potential energy, energy that is stored and potentially available for use.
Before potential energy can be used it is transferred into kinetic energy
7. Hydro energy
Hydroelectric power is electricity that is supplied by generating energy
from falling or streaming water. Hydroelectric power is a so-called
renewable energy source. This means that the source, which provides
the energy, can be renewed. This is because, unlike non-renewable
energy sources such as crude oil, we will not run out of water fully. It
can be renewed after we have used it for energy generation.
Water, like many substances, contains two kinds of energy. The first
kind of energy is called kinetic energy. This is energy that is used
during the execution of processes, such as movement. Because of
kinetic energy water can flow and waves can exist.
But water can also contain potential energy. This is energy that is
stored in the water. Stored, but not used. This energy can become
useful when water starts to flow. It will be transferred to kinetic
energy and this will cause movement.
8. Tides and Waves
Production of electricity from waves and tides is an option today. About
twice a day in high as well as low tides, water flows in and out of coasts and
estuaries. This water can spin turbines, in order to produce electricity. But
analysts have been taking a closer look at this form of energy supply and
they believe that tidal power can only make a tiny contribution to the
world's energy supply, because of the few suitable sites, the high
construction costs and the risk of equipment destruction by saltwater
corrosion. However, there are a few areas with the right conditions to
produce tidal power. France and Canada own the largest tidal energy
facilities right now.
There are two types of energy systems that can be used to extracted
energy: kinetic energy, the moving water of rivers, tides and open ocean
currents; and potential energy from the difference in height (or head)
between high and low tides. The first method - generating energy from
tidal currents - is becoming more and more popular because people believe
that it does not harm the environment as much as barrages or dams. Many
coastal sites worldwide are being examined for their suitability to produce
tidal (current) energy
10. Hard water
Hard drinking water is generally not harmful to one's health, but can
pose serious problems in industrial settings, where water hardness is
monitored to avoid costly breakdowns in boilers, cooling towers, and
other equipment that handles water. In domestic settings, hard water
is often indicated by a lack of suds formation when soap is agitated in
water, and by the formation of lime scale in kettles and water
heaters. Wherever water hardness is a concern, water softening is
commonly used to reduce hard water's adverse effects. Water's
hardness is determined by the concentration of multivalent cations in
the water. Multivalent cations are cations (positively charged metal
complexes) with a charge greater than 1+. Usually, the cations have
the charge of 2+. Common cations found in hard water include Ca2+ and
Mg2+. These ions enter a water supply by leaching from minerals within
an aquifer. Common calcium-containing minerals are calcite and gypsum.
A common magnesium mineral is dolomite(which also contains calcium)
11. Types of hardness
Temporary hardness
Temporary hardness is a type
of water hardness caused by
the presence
of dissolved bicarbonate
mineral (calcium
bicarbonate and magnesium
bicarbonate). When dissolved
these minerals yield calcium
and magnesium cations(Ca2+,
Mg2+) and carbonate and
bicarbonate anions (CO32-,
HCO3-). The presence of the
metal cations makes the
water hard. However, this
"temporary" hardness can be
reduced either by boiling the
water, or by the addition of
lime (calcium hydroxide)
through the softening
process of lime softening.
Permanent hardness
Permanent hardness is hardness (mineral
content) that cannot be removed by boiling.
When this is the case, it is usually caused by
the presence of calcium sulfate
and/or magnesium sulfates in the water,
which do not precipitate out as
the temperature increases. Ions causing
permanent hardness of water can be
removed using a water softener, or ion
exchange column.
Total Permanent Hardness = Calcium
Hardness + Magnesium Hardness
The calcium and magnesium hardness is the
concentration of calcium and magnesium ions
expressed as equivalent of calcium
carbonate.
Total permanent water hardness expressed
as equivalent of CaCO3 can be calculated with
the following formula: Total Permanent
Hardness (CaCO3) = 2.5(Ca2+) + 4.1(Mg2+)
12. EFFECTS OF HARD WATER..!
With hard water, soap solutions form a white precipitate (soap scum)
instead of producing lather, because the 2+ ions destroy the
surfactant properties of the soap by forming a solid precipitate (the
soap scum). A major component of such scum is calcium stearate, which
arises from sodium stearate, the main component of soap:
2 C17H35COO- + Ca2+ → (C17H35COO)2Ca
Hard water also forms deposits that clog plumbing. These deposits,
called "scale", are composed mainly of calcium
carbonate(CaCO3), magnesium hydroxide(Mg(OH)2), and calcium
sulfate(CaSO4). Calcium and magnesium carbonates tend to be
deposited as off-white solids on the inside surfaces of pipes and heat
exchangers
The presence of ions in an electrolyte, in this case, hard water, can
also lead to galvanic corrosion, in which one metal will
preferentially corrode when in contact with another type of metal,
when both are in contact with an electrolyte
13. HOW TO REMOVE HARDNESS OF
WATER..?
Base exchange process' is a chemical method by which, softening of
permanent hardness in water can be done on a large scale or for
household purposes. It is the most popular and effective means of
softening hard water. It was discovered by Dr. Robert Gans, who
found out the natural minerals called ‘Zeolites’, which is very
effective in softening water,
Soft water
The water that lathers readily with soaps are called soft water. It
describes type of water that contain few or no minerals like
calcium(Ca) or magnesium(Mg) ions. The term is usually relative to hard
water, which does contain significant amounts of such ions.
Soft Water mostly comes from peat or igneous rock sources, such as
granite but may also come from sandstone sources, since such
sedimentary rocks are usually low in calcium and magnesium.
However, soft water does have negative side effects and can be bad
for the heart. Thus it should be drunk in moderation if at all.
15. What is rain water harvesting…?
Rainwater harvesting is the accumulation
and deposition of rainwater for reuse before
it reaches the aquifer. Uses include water for
garden, water for livestock, water for
irrigation, and indoor heating for houses etc..
In many places the water collected is just
redirected to a deep pit with percolation. The
harvested water can be used as drinking
water as well as for storage and other
purpose like irrigation
16. Benefits of rainwater harvesting..!
•To harness good quality water resource now
being wasted
•To prevent groundwater depletion
•To augment the expensive piped water
supply
•To save expenditure on water
•To prevent soil erosion and urban flooding
•Inexpensive and simple technology
•Aids ecological conservation
17. Harvesting in India..!
In the state of Tamil Nadu, rainwater harvesting was made
compulsory for every building to avoid ground water depletion
Chennai saw a 50 percent rise in water level in five years and the
water quality significantly improved.
In Rajasthan, rainwater harvesting has traditionally been practiced
by the people of the Thar Desert.
At present, in Pune rainwater harvesting is compulsory for any new
society to be registered.
An attempt has been made at Dept. of Chemical Engineering, IISc,
Bangalore to harvest rainwater using upper surface of a solar still,
which was used for water distillation
There are good opportunities for Rainwater harvesting in
Kerala because Kerala is located in a geographical area with
two rainy seasons
19. History to
In the United States, the first
sustainability policy for
establishment of a national
environmental sustainability came in 1969
with the passage of the National
Environmental Policy Act (NEPA) whose
purpose was to "foster and promote the
general welfare, to create and maintain
conditions under which man and nature
can exist in productive harmony and fulfill
the social, economic and other
requirements of present and future
generations
20. Sustainability of water
in AUSTRALIA
Australia faces special challenges in
achieving sustainability. As the driest
inhabited continent on earth, water
resources are scarce and must be carefully
managed. It ranks 40 out of 188 countries
for water availability. The prevailing
drought conditions aggravated by global
warming demonstrate that levels of water
use are completely unsustainable in
Australia
21. Future of water
One of the biggest concerns for our water-based
resources..!is the sustainability of the
resources in the future
current and even future water resource
allocation. As water becomes more scarce the
importance of how it is managed grows vastly.
Finding a balance between what is needed by
humans and what is needed in the environment is
an important step in the sustainability of water
resources. Attempts to create sustainable
freshwater systems have been seen on a national
level in countries such as Australia, and such
commitment to the environment could set a
model for the rest of the world.
23. WAR OVER WATER (JORDAN RIVER)
The "War over Water" also the Battle over Water refers to a
series of confrontations between Israel and its Arab neighbors
from November 1964 to May 1967 over control of available water
sources in the Jordan River drainage basin. The 1949 Armistice
Agreements which followed the 1948 Arab–Israeli War, created
three Demilitarized zones on the Israel-Syria border. The
southernmost, and also the largest of stretched from the southeastern part of the Sea of Galilee eastwards to the Yarmuk River
where the borders of Israel, Jordan and Syria converged, The issue
of sharing the waters of the Jordan–Yarmuk system between
Israel, Syria and Jordan turned out to be a major problem.
In July 1953, Israel began construction of the intake of its National
Water Carrier at the Daughters of Jacob Jordan Bridge north of
the Sea of Galilee and in the demilitarized zone. Syrian artillery
units opened fire on the construction site. The United Nations
security council majority voted for resumption of work by Israel.
The Israelis then moved the intake to an economically inferior site
at the Sea of Galilee
24. Water politics in middle east
Issues relating to water supplies, then, affect international and interregional affairs, with disputes over countries’ rights and access to
water resources most often the cause of tensions in this arena. The
contended nature of some water provisions has tended to mean that
certain waters become more prone to political conflicts (those which
are primarily prone to this in the Middle East and northern Africa are
the Nile, Jordan and Tigris-Euphrates rivers. In order to secure
reliable levels of water access for their populations, states must either
have a large water supply in terms of economic availability, or their
rights to such supplies must be established.
Studies of water in the Middle East have also suggested that, in a
sensitive hydrological location, a country’s existing surface and groundwater access should be protected as a first priority if it is to begin to
address any water difficulties or shortages. Such measures as these
can be seen as being the primary responsibilities of national
governments or ruling authorities; and water is therefore closely tied
up with statehood and geographical territory in international relations,
and with the recognition and rights of nation states as the central
actors in this field
25. Objective:
The Narmada Dam Project, is a project
involving the construction of a series of
large hydroelectric dams on the Narmada
River in India. Sardar Sarovar Project
(SSP) is the largest multipurpose project
in it. The project was first conceived of in
the 1940s by the country's first prime
minister, Jawaharlal Nehru. The project
only took form in 1979 as part of a
development scheme to increase irrigation
and produce hydroelectricity. Of the 30
large dams planned on river Narmada,
Sardar Sarovar is the largest. With a
proposed height of 136.5 m, it's also high
on discord between the planners and the
Narmada Bachao Andolan. The multipurpose project will irrigate more than
18,000 square kilometers - most of it in
drought prone areas like - Kutch and
Saurashtra.
26. The Andolan
Narmada Bachao Andolan is the
voice of hundreds of thousands
of indigenous people and peasants
who are losing their land and
livelihoods to large dams on the
Narmada River. The nonviolent
satyagraha (insistence on truth)
of the displaced people for their
rehabilitation has spanned two
decades, challenging the
centralized development programs
and envisioning alternatives. The
movement has won policy changes
in World Bank and other multilateral funding agencies
27. The final verdict
The Supreme Court's decision is still pending, seeking
stoppage of construction of the Sardar Sarovar dam.
The court initially ruled the decision in the Andolan's
favor, thereby effecting an immediate stoppage of
work at the dam and directing the concerned states
to first complete the rehabilitation and replacement
process.
The Court deliberated on this issue further for
several years but finally upheld the Tribunal Award
and allowed the construction to proceed, subject to
conditions. The court introduced a mechanism to
monitor the progress of resettlement pari passu with
the raising of the height of the dam through the
Grievance Redressal Authorities (GRA) in each of the
party states. The court’s decision referred in this
document, given in the year 2000 after seven years
of deliberations, has paved the way for completing
the project to attain full envisaged benefits. The
court's final line of the order states, "Every
endeavour shall be made to see that the project is
completed as expeditiously as possible"