1. AUTHORS: THE STUDENTS IX-a E - MARTIN ADRIAN, X-a A – RADU IOANA, PASCU FLORINA, ZINCĂ CRISTINA, MAZILU COSMIN, XI-a H – GHIŢĂ LILIANA This project has been funded with support from the European Commission. This publication [communication] reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein. Water pollution

2. Introduction Water conducts all biological processes in nature and ensures the existence of life on Earth. Our planet has huge reserves of water represented by water from seas and oceans which contain approx. 1.4 billion km3 of water, that is 97.3% of all water on Earth. Only 2.7% of the Earth's water is freshwater, but humans actually have only 0.002% respectively 30 000 km3 of water from the water drained on the surface of the continents, the rest being stored as ice in the polar caps.

3. Water pollution Pollution occurs when, following the introduction of some substances - solid, liquid, gaseous, radioactive - waters suffer significant physical, chemical or biological modifications making them unfit or dangerous to public health, aquatic life, industrial fishing, industry and tourism. Water pollution can be: biological, chemical and physical.

4. SUR WATER POLLUTION

5. Biological water pollution due to biological agents (microorganisms and fermentable organic matter) leads to a strong bacteriological contamination of water, which results in the spread of diseases such as hepatitis or typhoid.

6. Chemical pollution includes: Synthetic organic substances pollution - detergents, pesticides, phenols Toxic pollution - nitrites, nitrates, cyanides, heavy metals - lead, mercury, cadmium, copper, zinc, chromium, nickel Oil and petroleum products pollution

7. Physical pollution waste and insoluble mineral residue resulting from quarries or mines. thermal pollution of water used as coolant in various processes in power plants and chemical industry. deposition of radioactive water used in nuclear power plants, radioactive waste.

8. The effects of pollution on water and the environment Modification of water qualities by changes in the physical qualities: color, temperature, electrical conductivity, radioactivity, through the formation of bottom deposits, floating foam or film; modifying the organoleptic qualities; changing chemical qualities by changing the pH, hardness, reducing the amount of oxygen due to organic matter content ; the increase of toxic substances; destruction of flora, fauna algae flourishing due to fertilizers (nitrogen and phosphorus)

10. The effects of water pollution on health Infectious Diseases: · Microbial diseases: typhoid, dysentery, cholera; · Virus diseases: polio, hepatitis epidemic; · Parasitic diseases: dysentery, giardiasis. Noninfectious diseases: caused by water contamination with potentially toxic chemicals: lead, mercury, zinc, cadmium poisoning Poisoning with nitrates, phosphates, pesticides

11. Mercury is a dangerous and volatile heavy metal. Nitrite and nitrate poisoning is very dangerous, and can lead to death.

12. Water situation in Romania-from the point of view of pollution Over 28% of rivers in our country fall into the lower categories of water quality below the limits set in Europe. The main pollution factors remain the lack of water treatment plants in cities, practicing solid waste discharges into surface waters, the use of coal in power plants.

13. Ways of protecting water - Prohibition of random evacuation of residues that may contaminate water - Construction of wastewater treatment plants - Destruction of pathogens through disinfection of wastewater - Restraint and collecting systems for radioactive substances from wastewater - Control of solid waste disposal

14. The planet needs us!