Conquering Chemistry-eutrophication (1 Viewer)

[ay_caramba]

is that the textbook which gives the wrong definition of it??

 

[Tommy_Lamp]

There have been about 6 threads on Eutrophication. Refer to them to see if the definition you have learnt is correct.

 

[xeriphic]

eutrophication is the presence of nutrients enriches waterways which allow aquatic plants to grow abundantly, that's the definition I know

 

[Tommy_Lamp]

xeriphic: Thats only half.
Eutrophication occurs when excess nutrients are pumped into a waterway, this stimulates the growth of organisms above the normal levels. When the nutrient supply ceases, there is not enough food to maintain the level of organisms, hence the waterway, effectively, die.

 

[slip]

yes thats text book has the wrong definition

 

[Paroissien]

xeriphic is technically right. The death of the waterway is a cause of eutrophication

 

[jumb]

which results in oxygen being consumed by the rotting crap.

 

[lucyinthehole]

isn't it the bacteria that eats the rotting crap that consumes the oxygen?

 

[Paroissien]

No the algae consumes the oxygen, causing it to die. It is the dead algae that provides the right conditions for bacteria which release toxins into the water, killing everything

 

[lucyinthehole]

so basically:

excess nutrients --> growth of algae --> all oxygen consumed --> algae dies --> increased numbers of bacteria --> toxins --> everything generally bad

???

 

[Paroissien]

Yep, that's the process as I understand it

 

[meyero]

How does the algae consume the oxygen? they are plants which should create oxygen through photosynthesis or am i just confused?

 

[lucyinthehole]

How does the algae consume the oxygen? they are plants which should create oxygen through photosynthesis or am i just confused?

algae are cyanobacteria... i'm not sure what that means though... good point

 

[meyero]

just looked it up in "atish's" notes and it gives the following explanation for eutrophication

Increase of algae in waterways --> algae grow at the surface reducing light for normal water-plants below – these die --> Increased number of bacteria of decay which consume oxygen --> Water becomes oxygen depleted --> End with a smelly pond covered with green scum.

 

[LSP]

How does the algae consume the oxygen? they are plants which should create oxygen through photosynthesis or am i just confused?

increase number in Cyanobacteria (blue-green algae) undergoes respiration which consumes dissolved oxygen in the night. Probably algae also undergoes respiration

 

[LSP]

algae are cyanobacteria... i'm not sure what that means though... good point

Green algae do not release toxic gas. However, in algal blooms blue-green algae is present which releases toxic gas, or poisons. This blue-green algae is called a cyanobacteria. Not algae

 

[eth]

Algae consume oxygen thru photosynthesis

 

[lucyinthehole]

Algae consume oxygen thru photosynthesis

you don't so biology do you? cos then you're screwed. photosynthesis takes water, carbon dioxide and sunlight and turns it into nutrients/energy for the plant and oxygen as a waste product

 

[meyero]

yes, but the algal bloom blocks sunlight which prohibits the formation of o2 by photosynthesis