Isolation and Characterization of Aquatic Humic Substances from the Bog 'Kleiner Kranichsee'

Surface water has been studied from the mountain bog 'Kleiner Kranichsee'. This bog is situated in the Johanngeorgenstadt area (Saxony/Germany) close to an abandoned uranium mine and mine tailing piles. The bog water contains about 130 mg/L of organics (primarily humic and fulvic acid).
First, bog water colloids were determined for their particle size and size distribution using photon correlation spectroscopy (PCS) and scanning electron microscopy (SEM) in combination with size fractionation by filtration. Second, about 400 L of the bog water were processed in order to isolate aquatic humic substances. SupeliteTM DAX-8 (Supelco) was used as adsorption resin. The humic material was separated into humic and fulvic acids. A total of 14 g of humic acid and 10 g of fulvic acid were isolated. The humic substances were characterized in terms of their elemental composition, functional properties including proton exchange capacity, charge/size ratios and spectroscopic characteristics. The results were compared with data of a commercial humic acid from Aldrich.