L. Lebideau et P. Dudoignon, EVIDENCE OF NATURAL DENITRIFICATION MECHA NISM AT BEUXES (VIENNE, FRANCE), Comptes rendus de l'Academie des sciences. Serie II. Sciences de la terre et des planetes, 322(7), 1996, pp. 555-562
The denitrification mechanism identified at Beuxes (Vienne, France) is
caused by the confinement of the Oxfordian limestone aquifer beneath
the clayey Cenomanian sediments. The measured increase of total iron a
nd SO42-, and the decrease of NO3-, dissolved O-2 and Eh are consisten
t with the petrographic observation of pyrite alteration. The denitrif
ication is established through 300 m of confinement (from 100 to 0 mg/
l NO3-). The denitrification rate of 0.9 to 1.7 mg NO3-/l/day suggests
the superimposition of the chemical and the microbial mechanisms (Thi
obacillus denitrificans).