On Earth there are about a billion and a half cubic meters of water, 97% of which consists of salt water seas and the remaining 3% are in the form of freshwater lakes, rivers , glaciers and groundwater. To pollute the cqua means modify the characteristics so as to render it unfit for the purpose to which it is intended .
There are different types of pollution:
· CIVIL : results from the discharges of the city à , when the acqu to spills of untreated sewage treatment ration into rivers or directly into the sea ;
· INDUSTRIAL : composed of different substances ch and depend on the industrial production;
· AGRICULTURAL : tied to ' overuse and misuse of fertilizers and pesticides, which is largely water-soluble, penetrate the soil and has undermine the aquifers.
A ome chemicals present in polluted air are particularly dangerous for the s EALTH man and for the survival of many species, such as chromium and mercury, which make it toxic and all hazardous wastes that contain them.
The industrial effluents contain a large amount à of pollutants and their composition varies depending on the type of production process. Their impact on the environment is complex: often toxic substances contained in these discharges reciprocame nte reinforce their harmful effects and thus the total loss is greater than the sum of individual effects. The chemical fertilizers used in agriculture and sewage produced by the farms are rich in organic substances, dilavat and rain, they go to pour into aquifers or surface water bodies . These substances are added often debris, more or less coarse you, which is deposited on the bottom of the basins. The phenomenon of acid rain which consists of a count lighting storm water by toxic substances atmosphere (carbon dioxide, sulfur dioxide, nitrogen dioxide, etc. ..), has devastating effects on forests, which may show a reduction in photosynthesis , and building structures, which deteriorate more rapidly.
There are two types of solutions to the problem of pollu tion :
· NATURAL For example I know that the rivers not always been able to purify themselves because contain bacteria that decompose organic matter from the remnants of tory living and dead.
· HUMAN : eg modern purifiers, where slurry pa SSAN through three distinct phases of treatment. The first, called primary treatment, consists of a series of physical or mechanical removal of debris coarse sediment particles in suspension and separation of oily substances. In the second stage, called secondary treatment, which oxidizes the organic matter dispersed in the slurry. The third is whether called tertiary treatment, is designed to remove fertilizzan you through chemical and physical processes. C the are other solutions such as reducing the concentration of pollutants by subjecting the material to a preventive treatment before discharge into the drainage system and the use of ponds or tanks to depurazion and sewage.
Stop polluted water!
On the Earth there are about one and a half billion cubic meters of water, 97% of which are salt water and 3% fresh water, divided into lakes, rivers, glaciers and water-bearing stratum.
There are different kind of water pollution:
· CIVIL POLLUTION: coming fro m the dumping of the cities, when water goes into the rivers or into the sea without being purified first;
· INDUSTRIAL POLLUTION: that depends on industrial production;
· AGRICULTURAL POLLUTION: that depends on excessive use of fertilizers and pesticides, which are water-soluble, so they can enter into the ground and pollute the water-bearing stratum.
Some of the chemical substances contained in polluted w ater are very dangerous for our health and for the survival of many animal and vegetable species; for example mercury and chrome are highly toxic waste substances.
Industrial dumping contain a lot of polluting substances and their composition depends on the process of production. Their impact on the environment is very complex: often toxic substances contained in industrial waste reinforce each other in their damaging effects, so the total damage is superior than the sum of the single effects. Chemical fertilizers used for agricultural and slurry coming from farming are full of organic substances which, carried by the rain, goes into the water-bearing stratum. Moreover the phenomenon of acid rain, which consists of the contamination of the rain by toxic substances present in the atmosphere (carbon dioxide, sulphur dioxide, nitrogen dioxide), has devastating consequences on forests, in which the activity of photosynthesis is reduced, and on buildings, that are damaged easily.
There are two kind of solutions to this problem:
· NATURAL SOLUTION: for examples, rivers have always been able to purify themselves because of bacteria that decompose organic substances coming from bones of dead animals;
· HUMAN SOLUTION: for example with modern purifiers, in which sewage goes through three steps of processing. The first one, also called first processing, includes a series of mechanic and physical processes for the removal of rough rubble, of sedimentation of the particle in suspension and of separation of oily substances. In the second step, also called secondary processing, organic material contained in the sewage is oxidized. The third phase, also called tertiary step, has the aim of removing fertilizers with chemical and physical process. There are other solutions, such as the reduction of the concentration of polluting substances by treating the material with a preventive process before sending it in the sewage, the use of fields of settling or Areas for the use of the purification of sewage.
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