Global water: water crisis

Hello everybody !

To begin this blog about water, here is the summary :

-Global water
– What is water?
-How can the tap water come in our house?
– Resources : water
-Water shortage
-Water pollution
-Deserfication
-Acidification of oceans

Have a nice visit 😉

What is water?

Water is a simple chemical compound that is liquid at ambient temperature and pressure. At ambient pressure, water vapor above 100 ° C and solid below 0 ° C. Its chemical formula is H2O, which is to say that each water molecule consists of one oxygen atom and two hydrogen atoms.

The origin of water on the Earth:
According to the Big Bang theory, Georges Lemaitre, Alexander Friedmann, Edwin Hubble and Albert Einstein ( investigators), the universe would be created approximately about 15 billion years. Initially, the density of the universe tends toward infinity, this ultra-dense state has been defined as the beginning of the universe age t = 0. The extreme conditions of temperature, pressure and density that were in the first moments did not allow the creation of atoms. The universe had to become cool. It was only after 300 000 years as elementary particles formed together to give birth to light bodies: mostly hydrogen and helium.

By continuing to cool, the Universe has seen the creation of many stars and planets. It was on one of them, the Earth, where we are. Indeed, this planet has had all the conditions for the development of life, and this is made possible by the presence of liquid water on its surface.

Source : wiki

How can the tap water come in our house?

Where does come from the water? The water come from a natural source, to get water, we use the underground who is full of water, it digs in the limestone and then the water appears.

Water comes from the sea, but the heat provides the evaporation and it forms a cloud, with the contact of the atmosphere layer, it becomes impure, so water has some impurities. Then it falls on the ground under form of rain, so it is going to be a little bit dirty. There is no problem because the water is going to cross through the ground, and filter by the rock, until a raincoat layer Over which it makes accumulate itself as a sponge.As it is regularly raining, the rainwater presses on the reserve, thus the water of the reserve just has to find a passage, and it sprung under pressure.It’s always the same water who is evaporate and who falls in rains since billion years.

All the the ressources in water are not the same in each country. For example Africa has not much water and if there is a drought, it becomes dramatic for the population who is very poor and need water. The water arrives rarely in the tap, to found water, the people have to walk until half a day sometimes. Even if in some place the water is abuntant, it is very dirty and can’t be used, but people drink that water, and they become ill : diarorea, cholera, dysenteria. 1 billions 400 millions people don’t have access to safe water.

So we come back with the cycle of tap water. A drop of chlore is add for 200 ml of water to kill the bacteria who can be found in the water. As water have to travel in the canalisation, the water can found others bacteria and the chlorine will protect it. In the context of a big city like Paris, the water goes in the aqueduct which is a kind of canalisation. When the water is in the tank (réservoir), we keep a little bit of chlorine and we put the water in a big reserve.
At each bath we use 150 L , each shower 60 L, when we go the the toilets 15 L , when we clean our teeth 1 L , and there is the water that we drink, all of this water go in the sewer. We let some chlorine to avoid the formation of bacteria. In the water we can found the nitrate and some herbicides, but there are controls very often. If there is a pollution, we isolate the tank from the distribution. Pure water doesn’t exist. When the water from rain goes throught the ground it is filtered, and it receives other element like calcium, limestone, iron. Rainwater runs off the fields where the agricultors put some fertilizer who contain nitrate. If there is too much nitrate, the plants can’t assimilate all the nitrate, so the nitrate goes in the water. It’s the same thing for the herbicides, but everything of that is under control. Water can be considered safe, when it has less than 50 ml gr of nitrate and 200 mgr of iron in one liter. Bevor this century we don’t know how to do this kind of test, so we put some trout, if there were sick, that meant that water wasn’t safe.
The water of the ”Seine” in France is filtred. In water of rivers it’s: not safe, it mixes with the ground, it contains rest of animals and plants. The Seine collects the water from the factories, cities, and even if it is traited, there is always organic waste. When it’s raining water runs off the roads. So this water can transport some gasoline, and it goes in the rivers.
In the station, after have keep the bigger waste, we keep the waste who is on the surface, for that we add a product who glue them to each other, it’s denser, so it sinks. Then we filter the water, by passing in layers of sand and some materials increasingly small. For each drop of water we need 12 hours to filter it. We eliminate the bad odors with charcoal. Even if the water is clear and odorless, it’s not finish. There is still some bacteria, we pass the water in two big pool who contains good bacteria, who will kill the bad ones. But there still some germs to disinfect water once and for all. Then water is tasted to verify is favour.

The big cities , the distribution of water are under control. For that water goes from the tap, the reserve must be higher than the tap. It’s the height of the columns who increase the pressure of water. More we go up the stages, more there is less pressure. We use pump to come up the water.
The wastewater, comes in the sewer and in the WWTP (station of epuration). We pass water in a big sieve and we allowed it stand, the sand falls down and oil, grease stay up and we keep the mud. The pollution is dissolved becaue of some bacteria. After the bactrie glue together, and sink, we just have to keep it, the water is not sage but just refine. So now the water can be rejected in a river.

Source

Resources : water

Resources can be defined as features of the environment which are needed and used by people. The world demand for resources is increasing because the people growth, so more people need ressources, the economique development, some countries try to develop themselves industrially and they try to raise their quality of life, the new technology needs energy, so more resource.
The Earth’s ressources may be protected with :
The conservation -> use something for a long time
Recycling-> use another time the same thing
Greater efficiency in existing resource use
Developing renewable resources-> Wind, waves
Controlling pollution-> reduce emissions from vehicules
Using appropriate technology
We have to portect the earth’s resources because if there isn’t any resource, we can’t live. We need to product energy or electricity, if there isn’t any energy – > No life

As we can see on the picture, there are different resources.

We will be concentrated in the water.

Source: geography lesson

Water shortage

According to forecasts, by 2025, for most inhabitants of the planet, water may be “inadequate ” or even “tragically inadequate” it is unlikely that the factors behind this situation are ready to disappear.

The consequence of the increase in population is because irrigation to feed the entire world population, agricultural productivity will increase significantly.

Irrigation already accounts for 70% of global withdrawals, this consumption( consommation) is excessive, it should still increase by 17% over the next 20 years. A improvement in the overall management of irrigation will actually control the growth of consumption.

Another challenge for the coming years is the satisfaction of all drinking water needs of humanity. Today, already one in five has no access to clean water. However, the UNO says the 33 megacities of more than 8 million people that will exist in 15 years, 27 will be located in less developed countries and therefore less able to respond to need. In addition, although small decreases in water consumption were observed for some years in the U.S. and Europe, are alarmist predictions, with 40% increase in municipal and domestic consumption in the next 20 years.
Solutions can reduce water consumption and limit losses: efficiency irrigation techniques and especially the widespread use of the most efficient, and reforming the structures of production and distribution of drinking water and build new, maintain reserves, fight against pollution, including cleaning up wastewater, recycled water … But all these measures will require huge investments and are therefore expensive.
This will therefore policy decisions at national and international, and investment priorities of countries and funding agencies, which play a role in the future management of the potential shortage of fresh water worldwide.

Source: translated and arranged by me

Water pollution

Pollution of water:

– Pollution of freshwaterAt first, what is a polluted water? It’s in 1967 (in Geneva) that this definition was chosen : ”
A watercourse is considered polluted when the composition or the state of its waters are, directly or indirectly altered because of human activity.”
For the rivers, lakes…. ( water area), we can distinguished two kind of pollution :
chemical and thermal
The chemical pollution is when organic or inorganic(mineral) matter or rejected in the rivers.

–The organic matter who are degratable, need for their transformation, a lot of oxygen. ( It’s essentialy sewage water or water who comes from industry.
–Organic matter nodegradable with the fermentations,. These substance non-biodegradable accumulate and stay in the river.
–The inorganic matter ( mineral matter) suspended , will fall on the ground of the river (because of the decantation); they come from the extraction of combustible minerals, Ores, building materials, firm of wash.
We have finally, dissolved or toxic mineral substances.

We have three categories, concerning the origin of these waste :

Industrial waste: acid, hycarbure, cleaners, …
Agricultural waste : excessive fertilizer, pesticides;
Urban waste : cleaners, etc.

What are the effects of this pollution?

Formation of mosses who prevent the reoxygenation of the river
Infiltration in the ground ( gasoline)
-Poisoning of the flora and the fauna by toxins
– Radioactivity of waters because of the development of the dangerous radioactive residues

thermal Pollution
Most of the time, it’s the factories who throw back some residues at 60-70 or sometimes 80 degrees.
In this case, there is pratically the destruction fauna and flora ( animals, plants who lives there).

An other thing is added : chemical reaction and the fermentation, who are faster in an high temperature, The fermentation keep all the oxygen, so the fishes don’t have oxygen to breathe.

The pollution of water is not only on the surface , it can affect the aquifer. Indeed the aquifers can have some pesticides. So they can’t be use as drinking water source.

Pollution of marine water
The oceans have long been considered as a big inexhaustible reserve. We had the image of something so vast, that the human pollution could disappear. But if we look now, the ”universal dustbin” can’t eat all the waste.
At first, the pollution goes to the river, then to the sea, to the ocean, where toxic substances continue their damage.

There were a lot of marine pollution , we will do a zoom on ”the oil spill” of Torrey Canyon ( april 1967).
The torry Canyon is a tanker ( boat countaining petrol) , this boat contained 170 000 ton of petrol and it wrecked … All the petrol was expanding on the britain coast and french coast.
So the petrol was crude, black, smelly and sticky. The consequence was disatrous.
Different method was used to control this oil pill. People used sawdust , shovels and wheelbarrows, pumps, but the worst was the use of precipitants and detergents. England used a lot of detergents (10 000 tons), so in addition to the initial dramatic effects of oil spills, there were some others effect , the destruction of flora and fauna was increase.

With this tragedy, we take intention on all the boat who throw petrol and their waste in the oceans.
The biological effect was for the birds. A lot of birds were trapped in the petrol.
The mortality was increasing with use of detergents in the sea. A lot of marine species were killed.
This oil spill happened in one moment, but we often forget that there is always pollution in the sea ( gasoline, thermal, chemical pollution).

We can compare this oil spill with the oil spill of the Gulf of Mexico.Snce the explosion, 20th April 2010, 800’000 liters of oil escaped each day from the pool underwater.
These leaks forms a big surface of 1500 square kilometers. The consequences of the spill were disastrous for the economy of the Louisiana, which lived a lot of people from fishing and tourism.To stop the spill, a lot aof method was used, without succes.
This U.S government classify this spill as a ”national disaster”.

Source:

Deserfication: relation with the water

Desertification is a phenomenon that causes such serious erosion of productive ground that the soil loses nutrients which remains essential for plant growth. The conditions are like in a desert.

Causes of deserfication:
Human activities may play a role in land degradation.

For many reasons, including poverty and overpopulation, people decides to destroy forest areas, practice poor irrigation and use of use of poor farming methods : Overcultivation, deforestation, overgrazing.

The natural process can be a cause of deserfication.
The climate change has an impact because since 1960 rainfall totals have been below the long term average for eight in every ten years. There is the loss of vegetation too because of the rainfall declines
there is a reduction a vegetation.

We can see a link between rainfall, drought and famine because there is too much rainfall, the plants don’t have time to absorb water, so they die. If there is some drought it means that plants don’t have water to feed themselves. If there is no plants , it means no food for animal or humans.
The rainfall have an impact on the deserts, when it rains, the desert stops moving, and when it stops raining the desert continues.

So we see the impact of water on the world, water is essential for life.

Source: Geography lesson

Acidification of oceans

Here an illustration of the acidification of oceans and a little video , to explain that.

Source:

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Source: http://www.google.ch
http://www.wikipedia.com
http://www.environnement.ecole.free.fr
http://www.20minutes.ch
http://www.youtube.com

I have translated or adapted each articles. I use these websites to have a global idea and I reformulate in my own words.