Which type of water contains a significant amount of H2S?

Rich water contains a significant amount of hydrogen sulfide (H2S). In the context of refining and gas processing, rich water refers to the water that has been in contact with the gas stream and has absorbed various compounds, including H2S, due to its higher solubility in water. When natural gas is processed or treated, particularly in gas sweetening operations, H2S can be removed, but some amount may still remain in contact with water used in the process.

Rich water is typically the output after gas treatment and contains not only H2S but potentially other volatile and soluble compounds. This makes it important to handle and treat this type of water properly to mitigate environmental and safety risks.

The other types of water mentioned, such as stripped water, lean water, and purified water, generally have lower concentrations of H2S. Stripped water is usually treated to remove H2S, lean water is water that contains lower concentrations of gas emissions, and purified water has undergone processes to remove contaminants, making it unlikely to contain significant amounts of H2S.