NAME: REETI BHATTACHARYYA
CLASS: X SECTION: ‘B’
ROLL NUMBER: 30
BOARD REGISTRATION NUMBER :
SCHOOL: ASHOK HALL GIRLS’
HIGHER SECONDARY SCHOOL
SCIENCE : Chemistry – Hardness of water
Biology – Recycling (water)
Physics – Water as a source of energy
SOCIAL SCIENCE : Geography – Water as a resource
Political Development – Movements (
Economic Development – Sustainability
HARDNESS OF WATER
WHAT IS HARD WATER?
Hard water is water that contains
SOME STRATEGIES TO
cations with a charge of +2,
‘SOFTEN’ HARD WATER
especially Ca2+ and Mg2+.
These ions do not pose any
For large-scale municipal
health threat, but they can
operations, a process known as
engage in reactions that leave
the "lime-soda process" is used
insoluble mineral deposits.
to remove Ca2+ and Mg2+ from
These deposits can make hard
the water supply. Ion-exchange
water unsuitable for many
reactions, similar to those you
uses, and so a variety of
performed in this experiment,
means have been developed to
which result in the formation of
"soften" hard water.
an insoluble precipitate, are the
basis of this process. The water
PROBLEMS WITH HARD
is treated with a combination of
slaked lime, Ca(OH)2, and soda
Mineral deposits are formed by
ash, Na2CO3. Calcium
ionic reactions resulting in the
precipitates as CaCO3, and
formation of an insoluble
magnesium precipitates as
ARTICLE ON HARD WATER (IN
Hard water a bane for Basaveshwaranagar
• BANGALORE: If you live in Basaveshwaranagar, boil and
purify water before you use it. A third of the households in
this locality are getting hard water.
• A random survey by the Karnataka State Pollution Control
Board (KSPCB) in Basaveshwaranagar, off Chord Road in
West Bangalore, found that 34% of households get bad
quality water. While water was of good quality in 66% of
the households, it was moderate in 31% households and
poor in 3%. The survey tested drinking water samples
TIMES OF INDIA
from 104 households in the area.
Determination of hardness in water
EQUIPMENT: hard water and soft water, tap waterkenzingen and denzlingen, soap
solution, graduated cylinder, 4 test tubes, 4
plugs, ruler and pipette.
• Pour 5 mL of reference sample ‘hard water’ into
a test tube, and 5 mL of reference sample ‘soft
water’ into another test tube.
• Using the pipette add soap solution to each of
the test tubes. Start with 0.5 mL portions. Then
go on to add soap solution drop by drop. Count
the drops! After each addition put the plug on
the test tube and shake it. Go on adding soap
solution until a 2 cm lasting9 foam layer is
HARDNESS IN ° HARDNESS
BIOLOGICAL SYSTEMS OF RECYCLING.
Biological processes remove most of the rest of the
contaminants. Water flows into aeration basins where oxygen is
mixed with the water. Microorganisms consume the organic
material as food, greatly reducing the BOD in the water. They
convert non-settleable solids to settleable solids and are later
themselves captured in final clarifiers, ending up in wastewater
biosolids. Many operators of WRC's consider themselves "bug
farmers", since they are in the business of growing and harvesting a
healthy population of microorganisms. Since the process is
biological, any chemical or substance harmfulAir is mixedinterfere
to life can with the
with the operation of a water recycling plant. This is why cities
prohibit discharges of untreated industrial wastes to sewers and
wastewater so that
promote education among citizens regarding the harmful effects
that dumping household chemicals. When the water recycling plant
survive to consume
cannot operate properly because chemicals are killing the
organic material in the
An aeration basin is a holding and/or treatment
pond provided with artificial aeration to promote
the biochemical oxidation of wastewaters.
• Injection of compressed air through submerged
• Motor-driven floating surface aerators.
• Motor-driven fixed-in-place surface aerators.
• Motor-driven submerged aerators.
Why is recycling of water
Landscape irrigation: People are recycling water irrigation
systems which are completely separated from the domestic
For industrial use: Processed waste water can be used in
industries in water sprinkling systems and in cooling towers.
Many industries use a great amount of water but the
purification is not much important in cleansing process.
For Farming :Where farming depends on the irrigation of
water, then depending on the extent of purification of water, it
can be used to irrigate many vegetables, vineyards, grain
crops and fruit trees.
Recreation :Recycled water can be used in outdoor fountain
displays, to water golf courses and for artificial snow. The
fountains give a very good luck to a park.
WATER AS A SOURCE OF
Hydroelectric Power- Hydropower makes use of the
kinetic energy water gains when it drops in elevation.
Typically, water dammed in a lake or reservoir is
released through turbines and generators to produce
electricity, Hydropower has been a staple of electricity
since the beginnings of the electric age. However, very
little of this potential is currently slated for
development. Significant legal and regulatory
impediments, such as land acquisition and
environmental protection, will be a part of any major
hydro project. Additionally, reservoirs are typically built
and managed as municipal water supply and flood
control systems and secondarily for power production.
Ocean Energy- Three distinct types of ocean
resource are commonly mentioned as possible
energy sources: tides, waves, and ocean
temperature differentials (ocean thermal energy
conversion, or OTEC).For example, tidal energy
schemes capture water at high tide and release
it at low tide. Wave energy generation devices
fall into two general classifications, fixed and
floating. In both cases, the oscillating motion of
an incoming and outgoing wave is used to drive
turbines that generate electricity. Tide energy
systems traps high tides in a reservoir. When the
tide drops, the water behind the reservoir flows
through a power turbine, generating electricity.
Ocean thermal energy conversion uses the
Saline Water- Saline and brackish water is common normally it poses a problem for fresh water supplies.
Several technologies, however, can take advantage of
saline water for energy production. These include solar
ponds and algae production. Solar ponds use the salt
water in such a manner that heat from sunlight is
effectively locked in the pool and can be used for a
number of process heat applications or electricity
production. The ability of the pond to store solar thermal
energy is unique and overcomes the resource variability
that is a drawback of traditional solar development. Salt
water algaes grow prolifically under cultivated conditions
and can be pressed to extract biodiesel feedstocks or
dried and burned for power production. Although neither
technology has been demonstrated beyond pilot levels,
Texas is fortunate in that regions with saline water
resources also tend to be very sunny. If coupled with
WATER AS A RESOURCE
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.
ADVANTAGES OF RAINWATER
Rainwater harvesting provides an independent water
supply during regional water restrictions and in developed
countries is often used to supplement the main supply. It
provides water when there is a drought, prevents flooding
of low-lying areas, replenishes the ground water level, and
enables dug wells and bore wells to yield in a sustained
manner. It also helps in the availability of clean water by
reducing the salinity and the presence of iron salts.
• Makes use of a natural resource and reduces flooding,
storm water , erosion, and contamination of surface water
with pesticides, sediment, metals, and fertilizers.
• Excellent source of water for landscape irrigation, with
no chemicals such as fluoride and chlorine, and no
dissolved salts and minerals from the soil.
• Home systems can be relatively simple to install and
Water conservation refers to reducing
the usage of water and recycling of
waste water for different purposes
such as cleaning, manufacturing and
irrigation. Water conservation helps
save energy, protect wild animals,
and prevent people from using so
much water that it cannot be
replaced with rain. Water is the
source of life for every living thing.
WHAT IS SUSTAINABILITY?
The use of various strategies
for employing existing resources optimally so that that a
responsible and beneficial balance can be achieved over
the longer term. Within a business context, economic
sustainability involves using the assorted assets of
the company efficiently to allow it to continue
functioning profitability over time.
WATER AND SUSTAINABILITY
How does water play a role in sustainable communities?
In a sense, the concept of sustainability is quite simple. It refers
to whether or not some aspect of the community continues to
work over time at an acceptable level of service. For water
service, this would mean that water continues to be available
for the period for which it was designed, in the same quantity
and at the same quality and the same cost as designed. If a
person can turn the tap on over 15 or 20 years time and the
water comes out at the same rate and quality, and at the
same cost, as the day the system was commissioned, then it
is a sustainable supply .
• These attributes of sustainability for water supplies can be
divided into three main components:
• Water Quantity
• Water Quality
• The Cost of Water Treatment
MOVEMENTS ON WATER
NARMADA BACHAO ANDOLAN
is a social movement consisting of adivasis, farmers,
environmentalists, and human rights activists against a
number of large dams being built across the Narmada river.
The river flows through the states of Gujarat, Maharashtra,
and Madhya Pradesh in India. Sardar Sarovar Dam in Gujarat
is one of the biggest dams on the river and was one of the
first focal points of the movement. Friends of River
Narmada is the unofficial website of the NBA.
Their mode of campaign includes hunger strikes and garnering
support from film and art personalities. Narmada Bachao
Andolan, with its leading spokespersons Medha
Patkar and Baba Amte, received the Right Livelihood Award in
There were groups such as Gujarat-based Arch-Vahini
(Action Research in Community Health and
Development) and Narmada Asargrastha Samiti
(Committee for people affected by the Narmada
dam), Madhya Pradesh-based Narmada Ghati Nav
Nirman Samiti (Committee for a new life in the
Narmada Valley) and Maharashtra-based Narmada
Dharangrastha Samiti (Committee for Narmada damaffected people) who either believed in the need for
fair rehabilitation plans for the people or who
vehemently opposed dam construction despite a
While Medha Patkar established Narmada Bachao
Andolan in 1989, all these groups joined this national
coalition of environmental and human rights
SUPREME COURT’S VERDICT:----
"The Narmada Bachao Andolan has rendered a yeoman's
service to the country by creating a high-level of awareness
about the environmental and rehabilitation and relief aspects of
Sardar Sarovar and other projects on the Narmada. But, after
the court verdict it is incumbent on it to adopt a new role.
Instead of 'damning the dam' any longer, it could assume the
role of vigilant observer to see that the resettlement work is as
CRITICISM:-humane and painless as possible and that the environmental
The Narmada dam's benefits
aspects are taken due care of." include provision of drinking water,
power generation and irrigation facilities. However, the campaign
led by the NBA activists has held up the project's completion, and
the NBA supporters have attacked on local people who accepted
compensation for moving. Others have argued that the Narmada
Dam protesters are little more than environmental extremists who
use pseudoscientific agitprop to scuttle the development of the
region and that the dam will provide agricultural benefits to millions
of poor in India. There had also been instances when the NBA
activists turned violent and attacked rehabilitation officer from
Narmada Valley Development Authority (NVDA) and caused
damage to the contractor's machinery.