Volatile sulfides and their toxicity in freshwater sediments

Abstract

Three forms of volatile sulfides (free hydrogen sulfide, acid‐volatile sulfides [AVS] and a new form, heat‐volatile sulfides [HVS]), were measured and their relationships discussed. Purging of some contaminated sediments with nitrogen at 22°C failed to remove all of the free H2S, even after 6 h. With freshly H2S‐spiked uncontaminated sediment, purging of H2S was complete after 2 h; however, if the spiked sediment was allowed to stand for 53 d, H2S continued to be purged, even after 43 h. The H2S likely originates from equilibrium reactions involving reduced sulfur species in the sediment. Uncontaminated sediment spiked with H2S was found to be highly toxic using a sediment‐contact bioassay employing Photobacterium phosphoreum. Addition of Fe3+, which sequesters the S2−, reduced the toxicity. Two other bioassays (ATP‐TOX and Toxi‐Chromotest), both involving a DMSO/methanol extract of the spiked sediment, showed greatest toxicity with spiked sediment that had been standing for 22 d. The results indicate that reduced sulfur species in sediment may be a cause of toxicity observed in contaminated anoxic sediments.

Metal Bioavailability and Toxicity in Sediments

“…Two other microbial based bioassays that have been used in sediment extract testing include the ATP-TOX and Toxi-Chromotest assays (Brouwer & Murphy, 1995). They were shown to be sensitive (as was the Microtox R assay) to the presence of reduced sulfur species in anoxic sediments.…”

Fatal Accidental Hydrogen Sulfide Poisoning: A Domestic Case

“…The sulfur‐reducing bacteria transform the sulfates to sulfides (S 2− ) and then to hydrogen sulfide. Poisonings occur when the pocket of H 2 S is released, which is usually what occurs in accidents in drains . In the present case, the pocket may have been released when the woman attempted to clear the sink pipe by using a plunger, causing massive and sudden release of H 2 S (it was noteworthy that no commercial chemical product for clearing pipes was found on the premises).…”

Storage of oil field-produced waters alters their chemical and microbiological characteristics

“…Furthermore, the persistence of sulfide between 8 and 20 days (Fig. 1d) in the microcosms containing RT oil field H water represents an equilibrium shift in the sulfur cycle between sulfidogenic microbes and sulfide-oxidizing NR-SOB [20], possibly due to toxigenic effects of increased sulfide concentrations on NR-SOB [4,22].…”