Yukti

Biology

Water Recycling

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

How is it done…?recycling graywater can also be doncost-

benefit analysis of a free, more labor-intensive 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

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 environmentsHouseholds, golf courses and recreational parks.IndustryWashing and cooling in power stations and mills.

Physics:

water as an

energy resource

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

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.

Tides and WavesProduction 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

chemistryHardness of

water

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)

Types of hardnessTemporary hardnessTemporary 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 (CO3

2-, 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 hardnessPermanent 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 HardnessThe 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+)

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

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 waterThe 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.

Geography

Water Harvesting

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

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

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

Economics

History to sustainabilityIn the United States, the first

establishment of a national policy for

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

Sustainability of water in AUSTRALIAAustralia 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

Future of water resources..!One of the biggest concerns for our water-based

resources in the future is the sustainability of the

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.

PoliticalDEVELOPMENT

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 south-eastern 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

Water politics in middle eastIssues relating to water supplies, then, affect international and inter-regional 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 ground-water 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

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 multi-purpose project will irrigate more than 18,000 square kilometers - most of it in drought prone areas like - Kutch and Saurashtra.

The AndolanNarmada 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 multi-lateral funding agencies

The final verdictThe 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'sfavor, 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"