unusual question to do with water samples (1 Viewer)

[Tim035]

When water is collected from the field there should be no air bubbles in the sample. Explain why?

I can't really think of why air bubbles should not be present besides the fact they'd lead to an over estimate of the volume of the water sample and may some how effect dissolved oxygen concentration.

 

[pLuvia]

Air must be exluded because it may contain unwanted particles that may dissolve in the water and if any algae is present in the water it cannot photosynthesise to bring the dissolved oxygen levels up

 

[Riviet]

they'd lead to an over estimate of the volume of the water sample and may some how effect dissolved oxygen concentration.

That's correct, air contains oxygen and if there are air bubbles, then the extra oxygen will eventually dissolve and add to the DO levels of the water.

 

[AreYouAlright?]

And we all know that if your DO readings are inaccurate... unless you use a winkler titration... by evaluating BOD using standard methods you're setting yourself up to have an incorrect BOD reading...