BOD

Oxygen Demand and Organic Pollutants

Intro

BOD, (biological oxygen demand) is the measure of the amount of dissolved oxygen needed by decomposers to break down organic matter in water. Testing for BOD will give you a good estimate of water quality and tell you if you have any organic pollutants present. It is important to know the BOD of a body of water because some species can not survive in low oxygen environments, a very low or high change in the BOD could change the ecosystem dramatically. The BOD can be tested using methylene blue indicator, which detects changes in oxygen levels.

Question
How do nutrients and heat affect dissolved oxygen?

Hypothesis
I think that in the sample with more thermal pollution and increased nutrients will have a very high BOD

Materials

Water stirring rod
500ml beaker wax pencil
hot plate 11ml milk
thermometer 4 test tubes
yeast methylene blue indicator
10ml graduated cylinder
2 50 ml fl...