water pollution

Water pollution

Water is undoubtedly the most widespread and common substance diffused in the environment and is one of the most important. In addition to being used as a source of life for plants and animals, it is used in factories and industries .Water can perform its functions only if it flows continuously. This performance is called “the water cycle”. Water can reach the sea not only through rivers but also flowing from the ground, after being infiltrated and having reached a shallow aquifer. One can easily guess that water can be contaminated not only through rivers but also through soil pollutants. An important cause of water pollution derives from the discharges of the organic material. The decomposition of organic substances consumes the oxygen in the water , sometimes up to slay the river fish. The main sources of organic pollution are: the city sewers , farms , industries and agriculture.

The city sewers: the sewages which are found in the sewers contain large amounts of human excrements , so they should go through treatment plants before being discharged into rivers. Unfortunately in Italy less than half of the discharges are purified. The sewage can contain microorganisms which cause some diseases such as cholera, salmonellosis etc. People are likely to get sick if they ingest these organisms (it can happen while taking a bath in the river or eat contaminated shellfish). Farms wash away the excrements, the sewage are partially used as fertilizers and partially discharged into rivers. Some types of industries, for example food industries, download organic materials directly into rivers. As far it regards agricolture fertilizers, both chemical and natural, they can pollute rivers.

Sources of pollution:Direct land based sources: urban-domestic-industrial waste waters, rain water that have collected on the ground polluting materialsIndirect land based sources: they are represented by the pollutants carried by rivers and during the transport have undergone a certain dilution.Atmospheric sources: for the fallout of radioactive substances due to land-based activities such as thermal and nuclear power plants.

But there aren’t only the negative aspects…. The state has created laws for the protection of the sea and also the reserves

The end

Simona , Giorgia, Maria Grazia,Beatrice e Paola!