Dr. Martin T. AuerMTU Department of Civil & Environmental Engineering

Units of Concentration(the lingua franca of the field)

Why concentration?Why concentration?driving force for -

• mass transport• chemical reactions• biotic effects

nutrients toxicity

Metric Metric prefixesprefixes … …

1012

106

terragram

metric ton (megagram)

Tg

MT

103 kilogram kg

100 gram g

10-3 milligram mg

10-6 microgram µg

10-9 nannogram ng

10-12 picogram pg

10-15 femtogram fg

And if that’s not enough … And if that’s not enough …

1024 yottagram Yg

10-24 yoctogram yg

Mass concentration units: mass per mass. Mass concentration units: mass per mass.

Onondaga LakeSyracuse, New York

Mass concentration units: mass per mass. Mass concentration units: mass per mass.

Mass concentration units: mass per mass. Mass concentration units: mass per mass.

Mass concentration units: mass per volume. Mass concentration units: mass per volume.

Bioaccumulation: Mass in Fish vs. Mass in WaterBioaccumulation: Mass in Fish vs. Mass in Water

Onondaga Lake, Syracuse, New York

Mass concentration units: mole per volume. Mass concentration units: mole per volume.

Units of moles (molarity, M) per liter are often used to report concentrations of materials dissolved in water.

Gram molecular weight is the mass of a substance, in grams, that numerically equals its molecular weight.

The mass of one mole of a substance is its gram molecular weight, e.g. for carbon, C, one mole weighs 12g.

Mass concentration units: mole per volume. Mass concentration units: mole per volume.

Mass concentration units: mole per volume. Mass concentration units: mole per volume.

Units of moles (molarity, M) per liter are often used to report concentrations of materials dissolved in water.

Gram molecular weight is the mass of a substance, in grams, that numerically equals its molecular weight.

The mass of one mole of a substance is its gram molecular weight, e.g. for carbon, C, one mole weighs 12g.

Mass concentration units: mass per volume. Mass concentration units: mass per volume.

Mass concentration units: mole per volume. Mass concentration units: mole per volume.

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

Other types of units: particle concentrations.Other types of units: particle concentrations.

Other types of units: representation by effect. Other types of units: representation by effect.

Other types of units: representation by effect. Other types of units: representation by effect.

Other types of units: representation by effect. Other types of units: representation by effect.

Organic Matter.Organic Matter.

2 2CO H

… what’s in here?

Organic Matter.Organic Matter.

2 2CO H

Carbohydrates(sugar and the polymers starch and cellulose)

Proteins(polymers of amino acids)

Fats ( Fats(formed from glycerol and fatty acids)

Organic Matter.Organic Matter.

2 2CO H

2 22 2 ( )C H OC H O OO

Photosynthesis

2 2 22( )C O HO COH O

Respiration

also …mineralizationoxidationstabilization

Representation by Effect - Organic Matter.Representation by Effect - Organic Matter.

2 2CO H

2 2 22( )C O HO COH O

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.

BOD - Representation by Effect. BOD - Representation by Effect.

… impacts on lakes and rivers?