POLLUTION OF SWEET WATERS

• polluting drainages
• organic substances
• synthetic detergents

EFFECTS

The organic substances come biodegradate, that are demolished and transformed in mineral salts from the bacteria that find themselves in sweet waters.
But the biodegradation process demands a lot of oxygen.
If the organic substances amount exeed, the waters have less oxigen so bacterium work go slowly and fishes can die for asphixia.
The oxigen absensce, besides, support anaerobic bacterium development that make tossic substances to a lot of fish and water plant.

Refusals coming from industrial activities;
Polluting substances:

• Organic fermentable refusals
• Heavy metals like lead, mercury, branch, chromium, cadmium
• Trichloroethylene, benzene, formalin, acids and dissolvents
• Warm water

EFFECTS
The organic refusals come frome, beyond that from the city drains, also from paper’s industries, wood’s industries, distilleries, brewery, slaughter houses, sugar-refinery, and industries to cannery.
The polluted water from these refusals can contain virus, bacteria and protozoons pathogenic, that are able to cause diseases infectious like hepatitis, colera, and other infections in the digesting apparatus

The heavy metals poison waters and accumulate themselves progressively in all the the alimentary chains organism, from
placton to the larger fish.
They can catch up also the man through the water and foods ingested.
For how much can seem strange, the warm water, even if is pure, can be polluting: draft of a pollution thermal.
Some industries as the thermoelectrials, the oil refineries and nuclear, capture large amount of water from the rivers.

All these things contribute to increase the world global warming! Na mean?