450003 SE Topics in environmental GeoScience III (2011W)

This semester the Topics in Environmental Geosciences Seminar will focus on humics and iron in their multiple roles as redox buffers, ligands and colloid forming substances in exogeneous geology and environmental geosciences. The lecture will address how humic substances and iron shape redox gradients and how the formation or dissolution of iron oxides, including colloids and nano-particles is determined by redox processes. The influence of the formation of humic and iron colloids on transport of contaminants and on element cycling will be discussed. Finally, interactions between humics and iron colloids will be elucidated. The lecture will discuss the fundamental geochemical mechanisms involved in these processes and show strategies of their quantitative treatment, e.g., in reactive transport models.