Removal of volatile organic compounds and hydrogen sulfide in biological wastewater treatment plant using the compact trickle-bed bioreactor

Odours emitted by biological wastewater treatment plants (WWTPs) may cause a nuisance and neg-atively impact people’s health. It is possible to tackle this issue using known deodorization technologies such as adsorption, absorption, combustion, catalytic oxidation, and biofiltration. However, applying some of these may lead to secondary pollution, high operating and investment costs, periodic replacing, utilising or regenerating reactor or filter bed, or using expensive catalysts. It is possible to avoid problems of this kind using the compact trickle-bed bioreactor (CTBB) technology to biodegrade odours emitted from WWTPs. A pilot-scale CTBB reactor, with a total volume of 1.07 m³, diameter of 0.8 m and height of 2.13 m, was installed on the premises of a municipal WWTP. At variable parameters of the biodegradation process, odour reduction was investigated using mobile measuring devices to detect hydrogen sulfide (H₂ S) and volatile organic compounds (VOCs). The factor of H₂ S conversion was 71%–97%, and that of VOC conversion was 82%–94% when the gaseous-phase flow rate ranged from 7–30 m³ h^–1, at pH = 7 in the liquid-phase. The research results confirm the significant potential of CTBB technology for application in the municipal sector.