Flux of Reduced Sulfur Gases

Seasonal field sulfur emission measurements (DeLaune et al., 2002b) were determined in a Spar-tina alterniflora salt marsh (10-12 ppt salinity), a Spartina patens brackish marsh (5-8 ppt), and a Sagittaria lancifolia freshwater marsh (0 ppt salinity), along a salinity gradient extending inland from the coast in the Mississippi River deltaic plain region of the coastal Lonisiana. Results 

Comparison of Potential Sulfate Reduction Rates for Louisiana Marsh Soil to Other Wetland Sites 

Belle Baruch, Goat Island, North Carolina King (1988) 

Hydrogen sulfide was the predominant sulfur gas emitted from the brackish marsh an average emission was 21.22 pg S m h (Table 18.13b). HjS emission ranged from 5.29 to 79.20 pg S 

TABLE 18.13a Spartina elterniflora Louisiana Salt Marsh  

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DeLaune R. D., Devai I., and Lindau C. W. (2002) Flux of reduced sulfur gases along a salinity gradient in Louisiana coastal marshes. Estuar. Coast. Shelf Sci. 54, 1003-1011. 

Many of the previous direct flux measurements have focused on two distinct ecosystems, intertidal mudflats and Spartina altemiflora salt marshes. These coastal systems have the potential for large emissions of volatile reduced sulfur gases due to the availability of sulfate and organic matter. Intertidal mudflats (3.4) have a tendency towards anoxia, with concomitant production of H S via sulfate reduction. . altemiflora marshes (4T5) release DMS through the... 

DMS Dimethyl sulfide, (CHsjzS a reduced sulfur gas produced by marine microbiota Dry deposition The flux of material from the atmosphere to the surface by processes other than precipitaHon. Examples are the gravitaHonal settling of large parHcles and absorpHon of gases such as CO2 and SO2 at the ocean surface... 

The majority of the work related to Pd-based membranes is on the highly permeable Pd-Ag alloy. The drawback is, however, that these alloys are prone to poisoning by CO and sulfur-containing gases " leading to reduced permeability, or even to complete deterioration of the membrane. " The extent to which this affects stability and flux depends on many parameters, and the reported literature appears only partly consistent in this respect. The latter is probably mainly due to the insufficient understanding of the reactions mechanisms and how the surface properties, which is usually not well described on the atomic level, varies with synthesis methods, thermal history, surface composition, morphology, etc. 

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