Inorganic Carbon

Inorganic Carbon Pools in Aquatic Systems

H20 + CO2

<-- --> (H2CO3) <-- --> HCO3-1 + H+ <-- --> CO3

-2 + H+ free  CO2     carbonic acid           bicarbonate          carbonate

Hardness and Alkalinity

Inorganic Carbon and Buffering

Low pH Waters

Travertine and High pH Waters

DIC in Rivers• Decomposition dominates over photosynthesis, so tend to

produce CO2 rather than consuming

- Respiration can be so high that CO2 is maintained above equilibrium

• Inflowing water high in CO2 from bacterial respiration

• High turbulence causes CO2 to be lost quickly, but can see high CO2 in non-turbulent areas and during low flows

• Rivers and streams also act to move alkalinity (i.e., HCO3- and

CO32-) to lakes or to the ocean

Inorganic Carbon Flux

Export of Alkalinity by the Mississippi River

DIC in headwater streams of different parent rock types (Shin et al. 2011)

Lake Nyos Before and After an Outgassing Event

Silent Death

A Solution

Standard Curve