Pilot plant evaluation for hydrogen sulphide biological treatment: Determination of optimal conditions linking experimental and mathematical modelling.

The paper presents results of the development of a biological treatment pro cess conducted in a pilot plant for a gas containing hydrogen sulphide. Exp erimental results in this system were modelled by dividing the process in t o an absorption of H2S followed by a biological oxidation of sulphide. This integrated model was used also to find the best operational conditions whi ch optimise the overall process performance. The H2S removal efficiency is limited by the absorption capacity of the packed column to about 35 percent for any high H2S input concentration at constant gas and liquid flow rates of 3.0 and 0.3 m(3) per hour. Biomass purges are reduced to a minimum. The economic analysis shows a significant reduction in annual costs compared w ith physical-chemical methods.