Insights into the removal of gaseous oxytetracycline by combined ozone and membrane biofilm reactor

Abstract

Gaseous emerging organic compounds (GEOCs) may harm human health and ecological environment. High temperature composting of livestock manure may produce oxytetracycline (OTC) waste gas. Here, we investigated treatment OTC in waste gas by combined ozone and membrane biofilm reactor (MBfR) with desulphurizing bacteria. The performance, the microbial community, gene function and the mechanism for OTC removal in the ozone-MBfR were evaluated. The ozone-MBfR system could achieve more degradation of OTC completely than MBfR. Desulfovibrio, Lentimicrobium, Aminivibrio, Thioalkalispira, Erysipelothrix, Mangroviflexus, Azoarcus, Thauera, Geobacter, Paracoccus, and Dethiosulfatibacter were the dominant genera. Pseudomonas, Escherichia, Bacteroides, Salmonella, Paracoccus, Stappia were contribution to OTC degradation. With the addition of ozone, the community diversity increased; some genera, such as Tenericutes- uncultured, and Desulfovibrio, increased in abundance, whereas others, such as Thauera, and Petrimonas, decreased. Ozone destroyed the enol structure in OTC molecular structure and produces biodegradable products, ozone oxidation was combined with biodegradation, to achieve thoroughly degrade OTC in waste gas. The novel hybrid ozone-MBfR is a cost-effective and robust alternative to GEOCs treatment.