Dissolved Oxygen

By Brigitte Aftandilian

Why is this test done?

• This test is done to measure the total amount of oxygen in the water. In other words, it is measuring how many oxygen molecules are stuck in between the water molecules. The water molecule is a type of shape that does not fit in exactly. That is why sometimes the oxygen molecules get stuck in between.

What does the test measure?

• This test is measuring how many molecules of oxygen are stuck in between the water molecules. In a way it is also measuring the health of the river. If the river has a dissolved oxygen reading of below 15, that means that there maybe won’t be enough oxygen to go around.

What units is it measured in?

• Dissolved oxygen is measured in parts per million or ppm. In other words, it is measuring how many oxygen molecules are stuck for every million.

What factors effect the test?

• There are many things that can effect the reading of a dO. test. One of the most common is when the waves are high and there is a lot of splashing, or maybe a waterfall. One other common factor is when you accidentally don’t follow one or more of the directions correctly.

ResultsJan

23/09

Weather

clear

Rain

no

Waves

ripples

Air temp.

0 C

Water temp.

0% C

D.O

no answer

Feb

2/09

Weather

Clear

Rain

no

Waves

ripples

temp.

2 C

Water temp.

8% C

D.O

14 ppm

Jan

14/09

Weather

Clear

Rain

no

Waves

waves

Air temp.

0 C

Water temp.

-5% C

D.O.

no answer

Jan

6/09

Weather

cloudy

Rain

yes

Waves

waves

Air temp.

5 C

Water temp.

0% C

D.O.

no answer

Feb

6/09

Weather Clean

Rain

no

Waves

no

Air temp.

0 C

Water temp.

2% C

D.O.

14.9 ppm

Feb

12/09

Weather Clear

Rain

no

Waves

ripples

Air temp.

10 C

Water temp.

4% C

D.O.

14.9 ppm

Jan

15/09

Weather Clear

Rain

no

Waves

ripples

Air temp.

0 C

Water temp.

5% C

` D.O.

no answer

Feb

23/09

Weather Clear

Rain

yes

Waves

ripples

Air temp.

4 C

Water temp.

7% C

D.O.

14.9 ppm

Conclusion

• Right now, with these results, it means that the river is fairly healthy. All the results came up to 14 to 15 ppm. Although, we might have measured the chemicals wrong or in the bucket the water might have shook. This reading is good because, it means that there is 14 to 15 parts of oxygen in every million. Like this, there will be enough oxygen for the fish, plants, bacteria, and everything else that lives under the Charles river.