Long Term Trend in the Aerosol Black Concentrations in the Arctic Region

Swedish fresh waters are often rich in aluminium depending on the underlying bedrock, water chemistry e.g. acidification status and TOC. Aluminium forms, present at circum neutral pH are not toxic to aquatic biota, but may however influence the bioavailability of other metals. This will occur due to competition of Al on organic carbon binding sites which will relese free metal ions affecting metal speciation (Fig.1) as well as toxicity. Measured free/labile Cu levels, using electro chemical detection - Anodic Stripping Voltammetry (ASV), combined with modeling (Visual minteq) showed that this occurs until a threshold level of Al in the water is reached. The concentration of free Cu increased and the organically complexed Cu (Cu-FA) decreased when Al was added (Fig. 1)