*
1) Hydrosphere (hidrosfera): all the water, in all the three physic states (solid, liquid
and gaseous), present in the Earth’s surface.
The Earth is the only planet in the Solar System that has liquid water, thanks to
its distance from the Sun and to its atmosphere. We have water in all the three
states:
❚ Solid water (snow and ice) is found in the poles, glaciers and permafrost.
❚ Liquid water is in the oceans, seas, rivers, lakes and underground water.
❚ Gaseous water (water vapour) is in the atmosphere.
*
Do you remember why atmosphere helps to have liquid water on Earth?
2) Salinity (salinidad): the concentration
of salts (the mass of salts by unit of volume)
in water. Its unit is grams per litre (g/L).
3) Salt water (agua salada): water in
seas and oceans has an average salinity of 35
g/L or more. This concentration of salts
makes it not drinking water (=not suitable for
cosumption).
4) Fresh water (agua dulce): water in
rivers, lakes, underground waters. Its salinity
is less than 5 g/L. Drinking water should be
less than 1 g/L.
By Peter Summerlin
*
*75 % of the Earth’s surface is covered with water, but very few is available
(=disponible) for living things. Why?
Total available water:
100 % ………………….2,5 %
0,4 % …………………. X
X= 0,01 % of the total water
of the planet is available for
living things.
This 0,01 % is not evenly
(uniformemente,
equitativamente) available around
the planet.
*
1) Water is a molecule (molécula =
combinación de átomos) composed by
two atoms of hydrogen and one atom of
oxygen (H2O).
2) Pure water is colourless, odourless and
tasteless (incolora, inodora e insípida). Water
is the only substance that is present in
nature in all three states (gaseous, liquid and
solid); liquid at room temperature (20 ºC).
Boiling point = 100 ºC. Melting point = 0 ºC.
*
Can you correctly place in the picture the following items?
Boiling point: 100 ºC Melting point: 0 ºC
3) The density of water in the solid state is lower
than in the liquid state (the contrary to all the other
substances). **Thanks to this property, ice floats
on liquid water and aquatic life can continue to
exist under the ice in frozen lagoons and rivers or
in the Arctic.
4) Water is the universal solvent (disolvente
universal), because it can dissolve (disolver) many
substances. ** Living things use water to transport
dissolved substances. Example: nutrients are
transported in blood (sangre) or sap (savia). **
Aquatic animals can breath underwater because
water is a good solvent of oxygen.
*Lower (más baja)
Higher (más alta)
Water has a high heat capacity (elevado
calor específico), it means that it heats up
or cools down very slowly (because the
energy needed to change its temperature
by 1 ºC is very high). This property makes
water a good temperature regulator
(buen regulador térmico). Regions in the
coasts have more moderate temperatures
than regions in the interior. ** Living
things use this property to regulate their
own temperature. Example: when our
body temperature rises we sweat
(sudamos). This sweat (sudor) on our skin
evaporates using body temperature, this
way we manage to cool down.
*
Water participates in a high number of
biochemical reactions (like our metabolism).
High capacity of adhesion (between water
molecules). In this property are based three
other properties: 1) Capilarity (capilaridad;
water can move against gravity inside thin
tubes) **water and mineral salts travel from
the roots to the leaves of the plants, 2)
Incompressibility (incompresibilidad)
**hydrostatic skeleton of some invertebrates
(jellyfish) and 3) superficial tension **some
insects can walk on water.
*
*
Hydrostatic skeleton: water can’t compress
Superficial tension
Jellyfish
*
*El ciclo del agua o ciclo hidrológico es el conjunto de procesos que permiten al agua cambiar de estado y circular
entre la atmósfera y la superficie terrestre describiendo un movimiento cíclico.
Las fuentes de energía que actúan como motor de este proceso cíclico son el Sol y la fuerza de la gravedad.
•El Sol hace posibles los cambios de estado al
suministrar calor al agua. Así se produce la
evaporación del agua de los mares, océanos y de las
aguas superficiales continentales, que pone en
marcha el ciclo del agua.
•La fuerza de la gravedad provoca las
precipitaciones, que devuelven el agua a la
superficie terrestre. Esta fuerza también es la
responsable del movimiento del agua desde los
continentes hasta los océanos.
*1) Consumptive use: (uso consuntivo) when the water
we use is not returned to the water cycle.
Some examples of consumptive use:
1st) Agricultural use: 79 % of the total consumptive
use. It includes agriculture (agricultura) and raising
livestock (cría de ganado).
2nd) Domestic use: (uso doméstico) around 12 % of the
total consumptive use. Personal hygiene, drinking,
cooking, domestic and urban cleaning.
3rd) Industrial use: In Spain, it represents 9 % of the
total consumptive use. Industry uses water as raw
material (materia prima), as a machine refrigerant or for
cleaning.
*
2) Non-consumptive use: (uso no consuntivo)
when the water we use is returned to the water cycle
without significant alterations (sin alteraciones
significativas o importantes).
Examples of non-consumptive uses:
1) Recreational activities (aquatic sports that do
not pollute the water, pools, water parks).
2) Transport (by ship)
3) Production of hydroelectric energy
*Some actions for a sustainable use (uso sostenible) of water:
In agriculture: change to drip irrigation (riego por goteo), increase irrigation
taxes (impuestos), reuse of wastewater (aguas residuales) for irrigation and water
(regar) plants in the evening to avoid evaporation.
At home: install devices to save tap water (instalar aparatos para ahorrar agua
del grifo), adjust the cost of water to its value, in gardening use plant species
adapted to the climate, fill completely the washing machine and the dishwasher
and use short cycles, close the tap while brushing your teeth or washing your
hands, take a shower instead of a bath, repair water leaks (fugas de agua), etc.
In industry: recycle the water used as refrigerant, reuse water in close circuits.
*Water pollution (contaminación del agua): is the alteration in
the composition of water that makes it inadequate for its intended
use (inadecuada para el uso al que se destina).
Pollution in oceans and seas: polluted rivers are the main
source (son la fuente principal) of pollutants and plastic debris
(desechos plásticos). Also oil slicks (mareas negras) due to oil
spills from petroleum maritime transport.
* Pollution of surface water; the main sources come from its
consumptive use:
1) Pollution from agriculture and livestock farming. Soil (el suelo) is
polluted by herbicides, pesticides and fertilisers used in agriculture and
by the large quantity of organic waste from livestock (ganado).
Afterwards, runoffs (aguas de escorrentía) or the infiltration make this
pollution reach surface waters and aquifers.
*2) Domestic pollution.
Wastewater is the water
polluted by domestic use. It
contains a lot of organic matter
(materia orgánica) and
detergents. When they reach
surface waters eutrophication
(eutrofización) happens. Some
organisms grow very quickly
with the excess of organic
matter and consume all the
oxygen available in water (some
algae and microorganisms). This
causes the death of many other
living things in the area.
*
3) Industrial pollution. Surface and groundwater can also be polluted
by industrial and mining discharges (por vertidos industriales o
mineros). Many toxic metals end up polluting water. Besides, the hot
water coming from the refrigeration of machines can be returned to
rivers killing many living things.
*Many people in developing countries (países en vías de desarrollo)
don’t have access to good quality water; they often drink water from the
same places where wastewater is discharged. This is the cause of
serious diseases, such as cholera (cólera) and typhoid fever (fiebre
tifoidea).
Other diseases are
indirectly caused by unsafe
water, such as malaria.
The larvae of the Anopheles
mosquito (the one that
transmits the disease) grow
in stagnant water (agua
estancada).
*
Polluted water also
causes diseases in
developed countries
(países desarrollados).
The accumulation of
heavy metals (metales
pesados) and other
pollutants in rivers,
aquifers, seas and
oceans can cause brain
damage (daños
cerebrales), damage to
other organs or even
death.
Fresh water in nature
Water treatment plant
(= planta potabilizadora) Wastewater treatment plant
(= planta depuradora)
Water for human
consumption
*In developed countries, drinking water does not come directly from the natural environment.
First, it is cleaned up and processed in water treatment plants. Then, after human use, it is also
treated before returning it to nature (to avoid eutrophication and pollution with detergents and other
chemical products) in wastewater treatment plants.
Agua en el medio natural
Agua para consumo humano
Estación de tratamiento
de agua potable
(= planta potabilizadora)
Estación depuradora
de aguas residuales
(= planta depuradora)
*
*(Ampliación)
In the following slides you should only study the definitions of drinking
water treatment and wastewater treatment.
Notice that the last step in the water treatment plants is disinfection
(desinfección), this is when chlorine is normally added (en ese momento es
cuando se añade el cloro)
If you are curious you can read how these water treatment plants work,
you can find these slides translated to make it easier for you.
*
*
*
*
Top Related