NAME: REETI BHATTACHARYYACLASS: X SECTION: ‘B’

ROLL NUMBER: 30BOARD REGISTRATION NUMBER :

B114084140086SCHOOL: ASHOK HALL GIRLS’ HIGHER SECONDARY SCHOOL

FA3

SCIENCE :- Chemistry – Hardness of water Biology – Recycling (water) Physics – Water as a source of energySOCIAL SCIENCE :- Geography – Water as a resource Political Development – Movements

( water ) Economic Development – Sustainability

HARDNESS OF WATERWHAT IS HARD WATER?Hard water is water that contains

cations with a charge of +2, especially Ca2+ and Mg2+. These ions do not pose any health threat, but they can engage in reactions that leave insoluble mineral deposits. These deposits can make hard water unsuitable for many uses, and so a variety of means have been developed to "soften" hard water.

PROBLEMS WITH HARD WATER.Mineral deposits are formed by

ionic reactions resulting in the formation of an insoluble precipitate. For example, when hard water is heated, Ca2+ ions react with bicarbonate(HCO3

-) ions to form insoluble calcium carbonate(CaCO3).

SOME STRATEGIES TO ‘SOFTEN’ HARD WATER

For large-scale municipal operations, a process known as the "lime-soda process" is used to remove Ca2+ and Mg2+ from the water supply. Ion-exchange reactions, similar to those you performed in this experiment, which result in the formation of an insoluble precipitate, are the basis of this process. The water is treated with a combination of slaked lime, Ca(OH)2, and soda ash, Na2CO3. Calcium precipitates as CaCO3, and magnesium precipitates as Mg(OH)2. These solids can be collected, thus removing the scale-forming cations from the water supply.

CHEMISTRY6.3% of hard water in India.

ARTICLE ON HARD WATER (IN INDIA)

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 from 104 households in the area.

TIMES OF INDIA2012

Determination of hardness in water samples (Boutron-Boudet)

EQUIPMENT: hard water and soft water, tap water- kenzingen and denzlingen, soap solution, graduated cylinder, 4 test tubes, 4 plugs, ruler and pipette.

PROCEDURE: • 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 formed.

• Repeat this procedure with the 2 water samples.

VOLUME(soap solution added)

HARDNESS IN ° dH

HARDNESS RANGE

0.5 ml 1.0 ml 1.5 ml

2.5° 5.0°

7.5°

SOFT

2.0 ml 2.5 ml 3.0 ml

10.0° 12.5° 15.0°

MODERATELY HARD

3.5 ml 4.0 ml 4.5 ml

17.5° 20.0°

22.5°

HARD

5.0 ml 5.5 ml 6.0 ml

25.0° 27.5°

30.0°

VERY HARD

OBSERVATIONS AND DATA

RECYCLING WATER

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 harmful to life can interfere with the operation of a water recycling plant.  This is why cities prohibit discharges of untreated industrial wastes to sewers and promote education among citizens regarding the harmful effects that dumping household chemicals.  When the water recycling plant cannot operate properly because chemicals are killing the microorganisms, water reuse programs are jeopardized and the quality of water discharged to receiving streams is lowered. 

BIOLOGY

Air is mixed with the partially treated

wastewater so that microorganisms can survive to consume organic material in

the water.

AERATION BASIN

An aeration basin is a holding and/or treatment pond provided with artificial aeration to promote the biochemical oxidation of wastewaters.

METHODS :• Injection of compressed air through

submerged diffusers.• Motor-driven floating surface aerators.• Motor-driven fixed-in-place surface aerators.• Motor-driven submerged aerators.SUBMERGE

D DIFFUSERS.

AERATIONBASIN.

Why is recycling of water important?

Landscape irrigation: People are recycling water irrigation systems which are completely separated from the domestic water supply.

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.

Construction :Recycled water can be used on a construction site for many purposes like concrete mixing and dust control. The concrete mixing is a fundamental process in building.

THE WATER RECYCLING PROCESS

WATER AS A SOURCE OF ENERGY

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. This fact lowers the potential impact of hydro development on the energy picture.

PHYSICS

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 difference in temperature between warm surface water and cold deep ocean water to make electricity.

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 ongoing fresh water chloride control efforts, exploitation of the saline water resource for energy production may be possible for modest additional investment.

SALINE WATER.

OCEAN ENERGY OR

MARINE ENERGY.

HYDROELECTRIC POWER

GENERATION.

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.

GEOGRAPHY

ADVANTAGES OF RAINWATER HARVESTING:---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 operate and it may reduce your water bill.• Promotes both water and energy conservation.• No filtration system required for landscape irrigation

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.

SUSTAINABILITY

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.

ECONOMICS

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 ANDOLANis 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 1991.

POLITICALDEVELOPMENT

FormationThere 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 dam-affected people) who either believed in the need for fair rehabilitation plans for the people or who vehemently opposed dam construction despite a resettlement policy.

While Medha Patkar established Narmada Bachao Andolan in 1989, all these groups joined this national coalition of environmental and human rights activists, scientists, academics and project-affected people with a non-violent approach.

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 humane and painless as possible and that the environmental aspects are taken due care of."

CRITICISM:--The Narmada dam's benefits 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.The NBA has been accused of lying under oath in court about land ownership in areas affected by the dam. The Supreme Court has mulled perjury charges against the group.

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