Comparison of two-stage and single-stage biofiltration for H2S and toluene co-treatment

• Autores: Lawrence C. C. Koe, Juan Liang
• Localización: Biotechniques for air pollution control: proceedings of the international congress Biotechniques for Air Pollution Control : A Coruña, Spain, October 5-7, 2005 / Christian Kennes (dir. congr.), María C. Veiga (dir. congr.), 2005, ISBN 84-9749-163-7, págs. 95-102
• Idioma: inglés
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• Resumen

  • Odorous compounds such as hydrogen sulphide (H2S) and volatile organic compounds (VOCs) are difficult to remove together because odour oxidation product is acidic and this decreases the pH in the bioreactor causing poor removal of VOCs. Two types of bioreactors (single-stage and two-stage bioreactor) have been used for the co-treatment of gas mixtures. A study was carried out to investigate their comparative performances for the simultaneous removal of an airstream containing H2S and a VOC represented by toluene.

    Results demonstrated that a two-stage bioreactor performance was more effective than a singlestage bioreactor because a two-stage bioreactor allowed for separate media beds of different microorganisms. In a two-stage bioreactor, most H2S was degraded in the first stage and this protected the second stage from significant acidification. Toluene was removed chiefly during the second stage operated at a neutral pH. GRTs exceeding 3s for H2S or 12s for toluene were required to obtain high removal efficiency in the two-stage bioreactor. Experiments also revealed that in both single and two-stage reactors, toluene did not have significant influence on H2S removal. However, inlet H2S concentration had obvious influence on toluene removal.