EUTROFIZAREA EUTROPHICATION prof Wiland AnnaMaria Colegiul Tehnic Dr

EUTROFIZAREA (EUTROPHICATION) prof. Wiland Anna-Maria Colegiul Tehnic “Dr. Ioan Rațiu” Turda

EUTROFIZAREA (EUTROPHICATION) http: //absorblearning. com/chemistry/demo/unit s/LR 1105. html#Eutrophication

EUTROFIZAREA (EUTROPHICATION) • Farmers across the world spread millions of tonnes of fertilizer on their land each year. This provides plants with the essential elements they need to grow well, such as nitrogen from ammonium nitrate fertilizer. These fertilizers must be soluble in water so that plants can draw up the nutrients through their roots. However, because it is soluble, the fertilizer can be washed from the soil in heavy rain. We say that it is leached out of the soil. And that's when our pollution problems start.

EUTROFIZAREA (EUTROPHICATION) • The nitrate fertilizers drain from groundwater into rivers and streams. Once in a river, the fertilizer promotes rapid growth of algae (a tiny plant) on the surface of the water. This stops light reaching other water plants, and also reduces the amount of dissolved oxygen in the water. Fish rely on this dissolved oxygen: without it, they die.

EUTROFIZAREA (EUTROPHICATION) • Of course, plants produce oxygen when they photosynthesize. So why do the levels of dissolved oxygen decrease as the mass of plants increases? The algae thrive at first, but when they die, micro-organisms have a feast feeding on and decomposing the dead algae. The microorganisms multiply rapidly with so much food available, and their activity uses up the oxygen in the water – unfortunately for the fish.

EUTROFIZAREA (EUTROPHICATION)

EUTROFIZAREA (EUTROPHICATION)

EUTROFIZAREA (EUTROPHICATION)

EUTROFIZAREA (EUTROPHICATION)

EUTROFIZAREA (EUTROPHICATION)

EUTROFIZAREA (EUTROPHICATION)

EUTROFIZAREA (EUTROPHICATION)