The present paper deals with a novel hydrogen sulphide abatement process applying a combined chemical-biological process. The authors already dealt with this subject in the paper ＇＇Biotechnological H2S gas treatment with Thiobacillus ferrooxidans＇＇ [1], previously published in Chemical Engineering and Technology. This study, in particular, deals with overall process test runs in a laboratory scale plant with a single-stage immobilised biomass reactor.