engleski

Organic matter concentrations and characteristics in bulk precipitations in Croatia

Organic matter, especially its reactivity and physico-chemical properties, play a crucial role in complex biogeochemical processes in aquatic environments. The interactions between the atmosphere and aquatic systems are of considerable importance for the fate, transport and cycling of organic matter and other microconstituents in the environment, having thus a decisive role in global changes and in environmental protection. Organic matter in atmosphere is a result of primary anthropogenic and biogenic emissions and/or of transformation processes of different precursors. The monitoring of chemical composition of rain has attracted attention of numerous investigators, but there is still lack of knowledge about chemistry of precipitation. The dissolved organic carbon (DOC) is the most relevant and most frequently used collective parameter for organic matter content. Surface active substances (SAS) contribute to the amount of organic compounds and play a role in the control of atmospheric processes, enhancing the potential of rain drops for washing out organic matter from the atmosphere and mobilizing micropollutants on the global level. In this work the dissolved organic carbon (DOC) and content of surface active compounds(SAS) have been measured in the samples collected in two cities in Croatia (1999 – 2009), one in continent and the other in coastal zone in the Middle Adriatic. The capacity of organic ligands to complex metal ions and the oxidation state of the organic carbon present were determined as additional parameters for qualititave and quantitative characterization of organic matter in precipitations, what is of special interest for understanding the pertaining physico-chemical processes. The results will be compared with those for water bodies (of marine and freshwater origin as well as seasurface microlayers) in the investigated area.

bulk concentration ; DOC ; surface active substances ; copper complexing capacity ; oxidation state

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