water tests again (1 Viewer)

[mr EaZy]

do we need to know all that stuff on sechi disks and wrinkler methods of tsting dissolved O2??
thats about the only things i dont get.

Also, how does one treat a low BOD in a river system?

 

[bubble_tea]

yep,
you don't need to treat the bod? its just an indication of how much oxygen is needed by the organisms in the water i think

 

[tina_goes_doo]

Actually i think treating BOD was one of the questions we got in our trial. Or something like that. And i think you should rephrase that question.

Low BOD is good. It means there IS a high concentration of dissolved oxygen.

Clear water may have a BOD less than 2.
Raw sewerage may have a reading in the hundreds.
Food processing wastes may be in the thousands.

So if you meant high BOD...i dunno. Aerate the water? Get rid of wastes? Kill bacteria and algae? Add more aquatic plants? Please don't lynch me over those answers. I really don't have an actual answer.

Hehe...and it "Winkler" not Wrinkler

I don't think you need to know about sechi disks but you should know something about the winkler method. Namely how they do it (back titration) but possibly not detailed steps. It is a lot to remember after all and the examiners arn't THAT bad.

 

[mr EaZy]

Actually i think treating BOD was one of the questions we got in our trial. Or something like that.

Thats why i asked!
i must have read it wrong, it was in one of the trails: yeah i would also aerate the water and filter out the organic matter

for wrinkler its a long procedure: adding mg2+ OH-
2I- etc. ill keep that in mind, or i can say that DO is measured with an O2 probe.

the point is that u need to know how to "know" if these problems are occuring in a riverway right?

like i think we had to do a prac to measure all these things right?

for the sechi disks, for turbidity. ill just fill two long tubes with turbid water and measure how long it takes for the X to dissapear

i think thats all
later days