High levels of hydrogen sulfide are sometimes observed in the pore water of eutrophic sediments. It is important to reduce the hydrogen sulfide concentration to maintain health ecosystems as well as aquaculture activities in enclosed water bodies. The purpose of this study is to reveal the removal mechanism of hydrogen sulfide using carbonated steel slag produced through carbonation processes to alleviate alkaline impacts. Batch adsorption experiments revealed that hydrogen sulfide was adsorbed onto carbonated steel slag based on a pseudo-first-order kinetic model; its adsorption maximum was 7.5 mg g(-1). The removal mechanisms of the hydrogen sulfide included (1) the formation of pyrite, and (2) oxidation to sulfur coupled with the reduction of manganese oxide on the carbonated steel slag. (C) 2013 Elsevier B.V. All rights reserved.