Peat biofiltration as an odour control technology for sulphur-based odours

Due to their low odour thresholds and common occurrence in sewage-treatment operations, volatile sulphur compounds are generally considered to be the most significant malodorants at sewage-treatment works. Biofiltration is an odour-control technology which has proven success in industrial and agricultural applications, and in more recent years has been applied in the water industry. Experiments were carried out using a test rig to measure the removal efficiencies of hydrogen sulphide and methyl mercaptan, when passed through peat-based materials, under a range of environmental conditions. Temperature, gas loading rate and inoculation with sulphur oxidizing bacteria were all found to significantly affect performance. Removal rates of over 99% of hydrogen sulphide, and 95% methyl mercaptan were achieved. Investigations of full-scale installations at sewage-treatment works supported the experimental results.