1. 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)

2. 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+)

3. 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

4. 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.

5. 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

6. 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.

7. How is energy generated in a hydroelectric power plant?
Read more: http://www.lenntech.com/water-energy-faq.htm#ixzz2m6UsLqWd
A hydroelectric power plant consists of a high dam that is built across a large river
to create a reservoir, and a station where the process of energy conversion to
electricity takes place.
The first step in the generation of energy in a hydropower plant is the collection of
run-off of seasonal rain and snow in lakes, streams and rivers, during
the hydrological cycle. The run-off flows to dams downstream. The water falls
through a dam, into the hydropower plant and turns a large wheel called a turbine.
The turbine converts the energy of falling water into mechanical energy to drive
the generator. It turns a shaft, which rotates a number of magnets in the
generator. When the magnets pass copper coils a magnetic field is created, which
aids the production of electricity. Step-up transformers will than increase the
voltage of the electricity, to levels needed for the journey to communities. After
this process has taken place electricity is transferred to the communities through
transmission lines and the water is released back into the lakes, streams or rivers.
This is entirely not harmful, because no pollutants are added to the water while it
flows through the hydropower plant.

8. 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.

9. Reclaimed water or recycled
water, is former waste
water (sewage) that is treated
to remove solids and certain
impurities, and used
in sustainable
landscaping irrigation or to
recharge groundwater aquifers.
The purpose of these processes
is sustainability and water
conservation, rather than
discharging the treated water
to surface waters such as rivers
and oceans. In some cases,
recycled water can be used for
stream flow augmentation to
benefit ecosystems and improve
aesthetics

10. Recycled water is filtered, treated and disinfected, and is suitable for a range of uses
All of our water reclamation plants produce Class C recycled water or better. This
water can be used for various purposes including irrigating sporting grounds, public
ovals, golf courses, crops and produce.
In the near future, Class A recycled water will be available for residential use.

11. 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
Raw sewage is 99.9% water. Large objects such
referred to as secondary treatment. Advanced as sticks and rags are removed from raw sewage
as it passes through bar screens.
secondary treatment usually involves applying
chemical systems in addition to biological ones,
such as injecting chlorine to disinfect the
water. In most of the United States,
wastewater receives both primary and
secondary treatment. Tertiary treatment
methods are sometimes used after primary and
secondary treatment to remove traces of
chemicals and dissolved solids. Tertiary
Next, wastewater is slowed so that settle able
treatment is expensive and not widely practiced organics settle to the bottom while fats, oils,
and greases float to the top.
except where necessary to remove industrial
contaminants.

12. IT IS USED FOR:
agriculture
landscape
public parks
golf course irrigation
cooling water for power plants and oil
refineries
processing water for mills, plants
toilet flushing
dust control,
construction activities
concrete mixing
artificial lakes