300629 VO Introduction to chemistry of natural fresh waters (2007S)

The lecture focuses on three principles of aquatic chemistry:
1)Chemistry of aquatic fresh water systems is to an high extent dependent on external (geographical situation, geology of catchment area or aquifer, shape of water body, climate etc.) as well as on internal parameters (availability of light, convections, exposition to winds, turbidity, productivity etc.).
2)Physical, chemical and biological parameters of natural aqueous systems are strongly interlacing and variable to time and local coordinates.
3)Every chemical feature of natural waters cannot be understood except within the context of interaction between water and adjacent solid phase (soil, sediment, aquifer, suspended matter).
Some topics of lecture:
electric conductivity:
dependence on concentration and diversity of ions, dependence on temperature
chemical mechanisms of weathering:
weathering by oxidation/reduction processes
significance of humic acid content for chelate induced weathering
proton induced weathering of carbonate rocks
differentiation of magma melt, crystal structure of primary silicates
acid weathering of alkaline silicate rocks
alkaline weathering of acid silicate rocks
secondary silicates:
smectites and further clay minerals
ion exchange capacity of clay minerals, isoelectic point, clay minerals and fertility of soil
natural buffer systems in soils, ground water and surface water systems
alkaline soils in arid and acidic soils in humid climate
acidification of soils by fertilisation
loss of organic soil components by cultivation soils
redox processes in natural waters:
concept of pE
oxic, suboxic and anoxic soil conditions
sequence of reduction reactions in neutral soils
nitrification and denitrification
sulphate reduction
fermentation
the nitrate problem in quaternary aquifers