Dissolved methane oxidation and competition for oxygen in down-flow hanging sponge reactor for post-treatment of anaerobic wastewater treatment

► The DHS reactor prevents dissolved methane emission from anaerobic treatment. ► The maximum oxidation capacity of the DHS is approximately 2.5 kg-O2 m−3 day−1. ► Organic matter and sulfide oxidation occurred prior to methane oxidation. ► Ammonia oxidation occurred finally if residual oxygen was present.