REMOVAL OF HYDROGEN SULFIDE FROM SOUR GASES USING A LOW-COST REUSABLE ADSORBENT MEDIA

Virtually every wastewater treatment plant, and many industries, produce off-gas which is high in hydrogen sulfide (H2S) concentration. Because of its toxic, odorous, corrosive nature, reduction 2 of H2S concentration in such gases is desirable. The objective of the research described in this 2 paper was to develop an adsorptive media with a performance exceeding that of existing media, capable of repeated regeneration, and low in cost.A filter media was prepared, consisting of a natural mineral, calcined to increase hardness, porosity, and surface area, with an iron oxide coating applied. Bench-scale testing in miniature filter columns showed the media capable of treating gas with an H2S concentration as high as 30,000 ppm, reducing this to less than 1 ppm.. Optimum performance was obtained with a contact time of 60 seconds and a linear velocity of 5 ft/s through the filter.The media was regenerated by blowing air through the filter. Color change from orange/red to black as the media became saturated with H2S, and back to orange/red as it was regenerated, 2 provided a useful visual indicator of the status of the media. Through the course of 15 regenerations and re-uses, the media adsorbed over 50% of its weight in H2S.A demonstration-scale plant was installed at a waste water treatment facility for three months, treating over 350,000 litres (12,000 ft3) of gas with 60–100 ppm H2S, providing reduction to less than 1 ppm.