What causes hydrogen sulfide?
Hydrogen sulfide is produced because of the microbial breakdown of organic materials in the absence of oxygen. H2S generation can occur in petroleum reservoirs, wastewater treatment plants, and sewers to name a few.
What are some of the hazards of H2S?
H2S is a colorless and deadly gas present in crude oil and many intermediate petroleum products. In recent years, industry and public concerns have heightened awareness of health and safety issues associated with H2S in petroleum products in refineries, terminals, shipping vehicles, and handling equipment. As a result, and in many cases, mandatory 10 ppm H2S vapor space specifications have been added to these products. The specifications must be met prior to product shipment from the refineries and terminals to ensure the health and safety of potentially impacted individuals.
What are the sources of H2S?
The direct introduction of hydrogen sulfide and other reduced sulfur compounds such as mercaptans generated from inorganic and organic reactions in petrochemical plants, paper mills, steel mills, and other industrial processes into process water and wastewater streams. In wastewater applications, a primary contributor to hydrogen sulfide is the biochemical reduction of inorganic sulfur compounds to sulfide by sulfate-reducing bacteria (SRB) under anaerobic or low dissolved oxygen conditions. The rate by which H2S is generated depends upon the concentration of organics, sulfate, and dissolved oxygen in the water and environmental factors such as pH and temperature.