Water rich in decaying organic material such as plants and waste is also typically rich with sulfate. In anaerobic environments, sulfate-reducing bacteria aid in the degradation of the organic matter by extracting energy from organic molecules. During this process, the sulfate is reduced to hydrogen sulfide, which remains in the water.
Amounts as low as .00047 parts per million can be detected in drinking water due to the infamous odor of rotten eggs given off by the gas. Hydrogen sulfide is corrosive, flammable, and poisonous in high concentrations.
While low concentrations of the gas are harmless, once the concentration rises above 10-20 ppm, it begins to become dangerous. Exposure can result in eye irritation, nausea, shortness of breath, fatigue, or loss of appetite, among other symptoms. Amounts above 320-530 ppm can be fatal.
Removal of hydrogen sulfide is a particularly complex issue due to the variety of possible causes and sources. In certain minor cases, a carbon filter may be sufficient. More likely, the solution involves transforming hydrogen sulfide into sulfur in a chemical process known as oxidation. This is often accomplished using aeration (pressurized air is injected into the filter tank), a catalytic agent such as manganese dioxide (MnO2), or some combination of the two. Each hydrogen sulfide problem is unique, requiring a unique solution that corrects the root cause of the issue rather than just the symptoms.
Homeowners should keep their eyes and nose open for signs of hydrogen sulfide, which can turn copper plumbing black. Anyone noticing the notorious rotten egg smell should have their water tested immediately. Follow the link below to learn more about the solutions available to commercial and residential property owners who have hydrogen sulfide problems.