Groundwater in-situ generation of aquatic humic and fulvic acids and the mineralization of sedimentary organic carbon

Citation
G. Buckau et al., Groundwater in-situ generation of aquatic humic and fulvic acids and the mineralization of sedimentary organic carbon, APPL GEOCH, 15(6), 2000, pp. 819-832
Citations number
19
Categorie Soggetti
Earth Sciences
Journal title
APPLIED GEOCHEMISTRY
ISSN journal
08832927 → ACNP
Volume
15
Issue
6
Year of publication
2000
Pages
819 - 832
Database
ISI
SICI code
0883-2927(200007)15:6<819:GIGOAH>2.0.ZU;2-G
Abstract
In this paper the groundwater in-situ generation of dissolved organic carbo n (DOC) is discussed based on the origin of groundwaters, their physico-che mical and isotopic properties, chemical composition and the dissolved inorg anic carbon (DIC) concentration and its C-13 content. Three aquifer systems are investigated. Two of these have relatively well defined hydrological a nd geochemical conditions (Fuhrberg and Munich) and are used as reference s ystems. The third aquifer (Gorleben) is a complex system containing DOC con centrations up to 200 mg C/L in deep groundwaters. From this aquifer system 19 groundwaters from different hydrogeochemical conditions are analyzed. T he in-situ generation of DOC is found to occur in conjunction with the micr obiologically mediated mineralization of sedimentary organic carbon (SOC). Thereby, SO4 is reduced and phosphate is released into the groundwater. Whe re SO4 is depleted, the mineralization of SOC occurs via fermentation, resu lting in CH4 generation. (C) 200 Elsevier Science Ltd. All rights reserved.