Freshwater sediments, total sulfur concentration

Total sulfur concentrations in freshwater lacustrine sediments described in these studies may reach about 1 % (8), but are generally less than 0.4%. Marine sediments in California generally have average total sulfur concentrations of less than 1%, but are usually greater than 0.6% (6). Values for pyritic sulfur of 0.31 to 1.98% are given for coastal and marine sediments of Long Island Sound (7). 

The other major reactant in Equation 1 is sulfate (SO42 ). Sulfate concentrations are highly variable in lake waters, from 3 x 10 5 mol/L in soft-water lakes in crystalline-rock drainage basins to 1.6 mol/L in hypersaline lakes (2.). In productive, freshwater lakes, sulfate reduction typically goes nearly to completion (5.). As sulfate concentrations increase, amounts of organic matter eventually become insufficient for complete sulfate reduction to occur. This is the case in "normal" marine sediment where a linear relation between total reduced sulfur and organic-carbon concentrations is observed. Sea-water sulfate concentration is 0.028 mol/L and the ratio of total reduced sulfur to organic-carbon concentrations (often referred to as S/C) in marine sediment is 0.33 ( ). ... 

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