WATER POLLUTION

GROUP 3Julia Brzozowska – Poland

Anna Hermanowska – PolandAgata Panasiuk - Poland

Hiurma Martín Cejas - SpainAlejandro Martínez González - Spain

Marta Peña Díaz - SpainPablo Rodríguez Hernández - Spain

Jorge Victorian Gago - SpainPaula Acha Evora - Spain

Alejandro Acosta león - SpainKaan - Germany

Water pollution - disadvantageous changes of chemical, bacteriological and physical properties of water caused by the implementation of inorganic, organic, radioactive substances, or heat in excess which limit or make the usage of water for drinking and economic purposes impossible.

Water pollution is caused mainly by the chemical substances, bacteria and other microorganisms which are present in natural water in the increased amount. The chemical composition of pollutants is being shaped with natural factors, e.g. dissolution of the substances present in the soil and rocks, the development and dying of aquatic organisms, and anthropogenic factors as well.

Division of pollutants:By the origin:

Natural: salinity, iron compoundsArtificial: wastewater, agricultural wastewater, water originating in the rubbish dumps

By a degree of the harmfulness:direct harm: gasworks, coke plants, factories of artificial fertilizers, pulp mills, factories of synthetic fibresindirect harm: the pollutants that lead to the curtailment of oxygen in the water below the level essential to keep aquatic organisms alive.

According to the criteria of the permanence of pollutants:point sources - wastewater drained in the organized way with plumbingsurface or area pollutants - pollutants rinsed with precipitationspollutants from linear or zone sources - pollutants produced by the means of transport

Degree of water pollutionThe degree of waters pollution is determined with so-called gauges of pollution which shows the amount of the substance in milligrams per 1 cubic dm of water. A concentration of dissolved oxygen which can reach the maximum level of 8,9 mg/dm is one of the most important indicators of surface water pollution - lower level of the oxygen concentration proves that water is polluted with organic compounds that are biodegradable; the decrease in the oxygen level below 4 ³ mg/dm causes many aquatic organisms die. The other indicators of natural water pollution is a biochemical oxygen demand which is a measure of the biochemical biodegradation of the organic compounds; a chemical demand of the oxygen - the measure of the content of all organic compounds;a presence of a mineral and organic suspensions as well as inorganic and organic compounds of nitrogen and phosphorus.

How to prevent water pollution:- putting meters on;- limiting artificial fertilizers which penetrate groundwater;- building the sewage farms;- installing filters in factories which waste is drained out with running water- not pouring cleansers (like soap, shampoo, washing powder, abrasives) to water- use bio of environmentally friendly detergents- taking care of the purity of water (not throwing cans and rubbish into water)