1. Dr. Martin T. Auer MTU Department of Civil & Environmental Engineering Units of Concentration (the lingua franca of the field)

2. Why concentration? driving force for - mass transport chemical reactions biotic effects  nutrients  toxicity

3. Metric prefixes … 10 12 10 6 terragram metric ton (megagram) Tg MT 10 3 kilogramkg 10 0 gramg 10 -3 milligrammg 10 -6 microgramµg 10 -9 nannogramng 10 -12 picogrampg 10 -15 femtogramfg

4. And if that’s not enough … 10 24 yottagramYg 10 -24 yoctogramyg

5. Mass concentration units: mass per mass. Onondaga Lake Syracuse, New York

6. Mass concentration units: mass per mass.

8. Mass concentration units: mass per volume.

9. Bioaccumulation: Mass in Fish vs. Mass in Water Onondaga Lake, Syracuse, New York

10. Mass concentration units: mole per volume.

12. A mole is one gram molecular weight of a substance. A gram molecular weight is the mass of a substance, in grams, that is numerically equal to its molecular weight. Thus one mole of carbon, C, weighs 12g, one mole of oxygen, O 2, weighs 32 grams and 1 mole of CO 2 weighs 44g. A 1 molar solution of CO 2 would contain 44g per liter. In environmental applications, we more typically encounter millimoles (mM) and micromoles (µM), i.e. based on mg/L and µg/L, respectively. Molarity (M, moles per liter) is often used to report concentrations in water. The advantage here is that the units are consistent with the stoichiometry of the reaction.

13. Mass concentration units: mass per volume.

14. Mass concentration units: mole per volume.

15. Other types of units: concentration as a common constituent.

16. Other types of units: particle concentrations.

17. Other types of units: representation by effect.

20. Organic Matter. … what’s in here?

21. Organic Matter. Carbohydrates (sugar and the polymers starch and cellulose) Proteins (polymers of amino acids) Fats ( Fats (formed from glycerol and fatty acids)

22. Organic Matter. Photosynthesis Respiration also …mineralization oxidation stabilization

23. Representation by Effect - Organic Matter. Respiration When organic matter is used as a substrate for respiration, … when it is oxidized … when it is mineralized … when it is stabilized it exerts a “biochemical oxygen demand” or BOD.

24. BOD - Representation by Effect. … impacts on lakes and rivers?