ASPECTS OF AQUATIC REDOX CHEMISTRY REDOX CONDITIONS IN NATURAL WATERS: PART II

Example Redox Impact on the Aquatic Cycling of Iron

Efficiency of Thermodynamic Predictions Measured Eh Vs Calculated Eh in Acid Mine Waters ACS, 1979

Limitations of Thermodynamic Predictions Measured Eh Vs Calculated Eh in Groundwaters From Lindberg and Runells, 1984 (Science)

pE-pH Diagram for Pb:

Profiles of dissolved “redox sensitive” chemical species in pore waters of a sediment core collected from an estuary in North Carolina Where do the ammonia and phosphate come from?

Profiles of dissolved nitrate, manganese and iron in interstitial waters of a marine sediment core Mn4+(s)Mn2+(aq) Fe3+(s)  Fe2+(aq) NO3- (aq) NO2-(aq)

Idealized distributions of temperature (T) and dissolved oxygen (DO) in “oligotrophic” and “eutrophic lakes” Spring turnover Summer stratification Fall turnover Winter stratification mg O2/L mg O2/L mg O2/L mg O2/L mg/L………………..mg/L………….mg/L…………..mg/L……

REDOX BUFFERS AND REMEDIATION pe Amount of organic matter reacted (arbitrary scale) Changes in pe of a water in contact with sediment as a function of the amount of organic matter decomposed