Effect of chemical composition of coal ash used to prepare granulated coal ash on the removal of hydrogen sulfide from water

Abstract

AbstractGranulated coal ash was prepared by mixing coal ash derived from a coal electric power plant and blast furnace cement, to remove hydrogen sulfide from aquatic environment. In this study, we investigate the effects of the composition of the coal ash used to prepare the granulated coal ash on its hydrogen sulfide removal performance. Manganese, magnesium, and calcium contents in the granulated coal ash were found to be the major factors in controlling the rate of hydrogen sulfide removal. The kinetics of hydrogen sulfide removal by the granulated coal ash were expressed as a first‐order equation with a rate constant of 0.0081–0.080 h−1. The rate constant for hydrogen sulfide removal obtained in this study correlated well with the manganese content in the granulated coal ash. The increasing surface pH attributed to the hydrolysis of calcium and magnesium on the surface of the granulated coal ash slightly increased the hydrogen sulfide removal rate.Practitioner Points Adsorbents for H2S are prepared by coal ash from different coal blend and coal electric power generation processes. Adsorbents tested in this study could remove hydrogen sulfide effectively. Manganese oxide in the adsorbents enhanced the removal rate of hydrogen sulfide. Adsorbents tested in this study contribute to sustainable development goals in terms of coal fly ash recycling.