La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Sulfide Inhibition of Nitrate Removal in Coastal Sediments
Auteurs :	C. Marjorie Aelion, Auteur ; Ulrich Warttinger, Auteur
Type de document :	Article
Dans :	Estuaries and Coasts (33(3) MAY 2010)
Article en page(s) :	798-803
Résumé :	Microbial nitrate (NO(3)(-)) removal via denitrification (DNF) at high sulfide (H(2)S) concentrations was compared in sediment from a coastal freshwater pond in a developed area that receives salt-water influx during storm events, and a saline pond proximal to an undeveloped estuary. Sediments were incubated with added SO(4)(2-) (1,000 mu g per gram dry weight basis (gdw)) to determine whether acid volatile sulfides (AVS) were formed. DNF in the sediments was measured with NO(3)-N (300 mu g gdw(-1)) alone, and with NO(3)-N and H(2)S (1,000 mu g S(2-) gdw(-1)). SO(4)(2-) addition to the freshwater sediments resulted in AVS formation (970 +/- 307 mu g S gdw(-1)) similar to the wetland with no added SO(4)(2-) (986 +/- 156 mu g S gdw(-1)). DNF rates measured with no added H(2)S were greater in the freshwater than the wetland site (10.6 +/- 0.6 vs. 6.4 +/- 0.1 mu g N(2)O-N gdw(-1) h(-1), respectively). High H(2)S concentrations retained NH(4)-N in the undeveloped wetland and retained NO(3)-N in the developed freshwater site, suggesting that potential salt-water influx may reduce the ability of the freshwater sediments to remove NO(3)-N.

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