1. Aquatic Chemistry 367 Civil and Environmental Engineering Meeting time: MWF 11:00-11:50am Meeting room: Abbott Auditorium in Pancoe Pavillion Instructor: Jean-Francois Gaillard, jf- gaillard@northwestern.edu Grader: Amy Dahl, a-dahl@northwestern.edu

2. Logistics Introductions http://www.civil.northwestern.edu/ehe/cour ses/ce-367/ce-367.htmhttp://www.civil.northwestern.edu/ehe/cour ses/ce-367/ce-367.htm Keep on top of the homework!

3. Why study Aquatic Chemistry?

4. Required for life Pollution transport almost always requires water Many environmentally relevant reactions occur in water Critical for controlling cycling of many elements –Nutrients –Toxins –Oxygen, nitrogen, carbon dioxide – atmosphere control

5. Applications of aquatic chemistry: Arsenic Chromium Mercury Acid mine drainage Global warming

6. What is water? Universal Solvent Required for life Molecular structure Hydrogen bonding: water clustering Anomalous behavior compared to other liquids

7. Sediments e.g.,amorphous or crystalline solids Soluble SpeciesSuspended Particles Small Complexes e.g.,Inorganic Metal Complex Me(CO 3 ) n y- Complexes with Macromolecules e.g., Fulvic Acid Particles Colloidal, aggregates Oxides (Al, Fe, Mn, Si) Adsorption: surface complexation Co-entrainment Living Organisms Intra/extra-cellular Oligoelements Toxicity Defense Mechanisms Hydrated Ion Me n+ (H 2 O) n Sediments! e.g.,amorphous or crystalline solids (precipitates and mineral formation) Soluble SpeciesSuspended Particles Small Complexes e.g.,Inorganic Metal Complex Me(CO 3 ) n y- Complexes with Macromolecules e.g., Fulvic Acid Particles Colloidal, aggregates Oxides (Al, Fe, Mn, Si) Adsorption: surface complexation Co-entrainment Living Organisms Intra/extra-cellular Oligoelements Toxicity Defense Mechanisms Hydrated Ion Me n+ (H 2 O) n Hydrated Ion Me n+ (H 2 O) n What is in water?

8. Dissolved ions: –Major Cations (Ca, Na, Mg, K, Fe) –Trace elements (Zn, Cr, Cu, Cd) –Anions (F, Cl, nitrate, sulfate) –Complexes (non-charged) –Organic molecules (humic substances) http://www.ar.wroc.pl/~weber/kwasy2.htm Particulate –Organic matter –Clays –Oxides

9. Chemical Reactions Acid-base chemistry Coordination chemistry Precipitation and dissolution Redox reactions

10. Kinetic approach Does not assume equilibrium has been reached Use a rate constant, k, to describe the rate of formation of products or consumption of reactants

11. Thermodynamic explanation Assumes equilibrium of a reaction is reached Simplifies solving mathematical expressions of chemical systems Use an equilibrium constant, K, to describe ratio of products to reactants