ABSTRACT

H₂S and NH₃ gases are toxic, corrosive, and malodorous air pollutants. Although there are numerous well-established physicochemical techniques presently available for the treatment of the gases, the growing demand for the more economical and improved process has prompted investigations into biological alternatives. In biological methods, H₂S was oxidized to SO₄ ^2- by sulfur-oxidizing bacteria, and then NH₃ was removed by the chemical neutralization with SO₄ ^2- to (NH₄)₂SO₄. Since the accumulated (NH₄)₂SO₄ could deteriorate microbial activity, it is important to screen an effective sulfur-oxidizing bacterium that has tolerance to high strength of (NH₄)₂SO₄ for the simultaneous removal of H₂S and NH₃. In this paper, a sulfur oxidizing bacterium showing the tolerance to high strength of (NH₄)₂SO₄, had been isolated, and identified as Acidithiobacillus thiooxidans TAS. When single H₂S was supplied to the ceramic biofilter inoculated with A. thiooxidans TAS, H₂S removal was maintained at almost 100% until inlet H₂S concentration was increased up to 970 ppmv and space velocity up to 500 h^-1, at which the elimination capacity of H₂S was 810 g-S · m^-3 · h^-1. However, when NH₃ was simultaneously supplied to the biofilter with H₂S, the maximum H₂S elimination capacity decreased to 650 g-S · m^-3 · h^-1. The critical points of inlet H₂S load that guaranteed over 99% H₂S removal was determined as 400 g-S · m^-3 · h^-1 under the coexistence of NH₃.

	SIMULTANEOUS REMOVAL OF HYDROGEN SULFIDE AND AMMONIA GASES IN A BIOFILTER [.pdf, 513.7Kb]
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