NYA PERSPEKTIV PÅ FÖREKOMST OCH URSPRUNG AV ADSORBERBAR ORGANISKT BUNDEN HALOGEN (AOX) I MARK OCH VATTEN / New Perspectives on the Presence and Origin of Adsorbable Organic Halogens (AOX) in Soil and Water
The present study has shown that surface water, groundwater and soil, even in areas far from industrial emissions, contain large pools of adsorbable, organic halogens (AOX). Gel chromatographic fractionations and studies of adsorption of AOX on activated carbon at different pH values indicated that a considerable fraction of the organohalogens are associated with high molecular weight organic acids. In surface water, the ratio between AOX and total organic carbon (TOC) varied between 730 and 8600 ìg/g. In soil, the AOX content ranged from 210 to 1400 ìg AOX per g organic matter. The fact that AOX (230-370 ìg /g) could be detected in fulvic acids isolated from old groundwaters (> 1000 yrs) indicates a large natural production of organohalogens. This hypothesis was further strengthened by mass balance calculations. In a raised bog (Komosse), the pool of AOX was estimated to be at least 300 times larger than the present annual deposition onto the bog. Potential artefacts in the analytical procedures used are discussed.