Effect of Surface Properties of Iron Oxide Sorbents on Hydrogen Sulfide Removal from Odor

Hydrogen sulfide (H2S) removal is the key issue for the odor control of sewage treatment facilities. In this paper, the iron oxide sorbents with different surface acid-base properties were prepared by acid and base modification. Effect of surface properties of iron oxide sorbents on H2S removal was revealed by the characterization of surface pH, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and solid-state NMR spectroscopy. The results show that the activity loss of the iron oxide sorbent is mainly due to the gradual oxidation of H2S into elemental sulfur and further into the sulfuric acid and sulfurous acid with time on stream. Meanwhile, the surface basic environment of base-treated iron oxide sorbent significantly increases the H2S removal activity by suppression the formation of H2SO4 or H2SO3 during the desulfurization process. Our findings will help us to prepare novel sorbent for more effective H2S removal from, e.g., odor gas.