Hydrogen sulfide removal from small quantities of gas such as biogas or landfill gas is usually carried out via technologies based on its adsorption onto solid sorbents. Biogas or landfill gas has a high moisture content; thus, for H2S removal, nonpolar-activated carbon is the most suitable sorbent. However, the adsorption capacity of common activated carbon for H2S is small. Therefore, sorbents that have been properly impregnated are often used because they react with H2S to form various products. This leads to great differences among the different sorbents regarding the adsorption capacity and H2S removal efficiency. Various commercially available impregnated sorbents for H2S capture were tested at different reaction conditions (type of impregnation agent, gas moisture content, and oxygen presence in gas). The test results showed that the H2S adsorption capacity of the sorbents is strong depending on the reaction conditions. To properly select a suitable sorbent for a specific industrial application, it is necessary to know the gas composition, in particular, oxygen and water content.