Removal of hydrogen sulfide gas using coal fly ash – blast furnace cement composite

The number of complaints regarding offensive odors from service industries, such as restaurants and garages, has recently increased. In this study, we aimed to develop an adsorbent for hydrogen sulfide gas derived from domestic wastewater and reveal the mechanisms of its removal. The adsorbent used for hydrogen sulfide gas removal was prepared by mixing coal fly ash and blast furnace cement with a mixing ratio of 87:13 by mass percentage. The optimum calcination temperature of the adsorbent was 700 °C to achieve a high removal performance for both dry and humid hydrogen sulfide gas. The X-ray absorption fine structure analysis revealed that hydrogen sulfide was removed on the adsorbent by oxidizing to sulfate. A pilot-scale experiment was conducted to evaluate the removal performance of hydrogen sulfide gas derived from domestic wastewater using the developed adsorbent. For a week, the average removal percentage of hydrogen sulfide gas derived from domestic wastewater remained at 99.1%. Therefore, the developed adsorbent for hydrogen sulfide gas is promising and cost-effective for promoting the recycling of coal fly ash. HIGHLIGHTS Adsorbent for H2S gas was prepared by mixing coal fly ash and blast furnace cement.; Adsorbent could remove both dry and humid H2S gas.; H2S was oxidized to sulfate and removed from the adsorbent.; Average removal percentage of H2S gas remained at 99.1%.; This study contributes to sustainable development goals in terms of coal fly ash recycling.