Anaerobic methanethiol degradation in upflow anaerobic sludge bed reactors at high salinity (> 0.5 M Na+)

Abstract

The feasibility of anaerobic methanethiol (MT) degradation at elevated sodium concentrations was investigated in a mesophilic (30°C) lab-scale upflow anaerobic sludge bed (UASB) reactor, inoculated with estuarine sediment originating from the Wadden Sea (The Netherlands). MT was almost completely degraded (>95%) to sulfide, methane and carbon dioxide at volumetric loading rates up to 37 mmol MT·L-1·day-1, 0.5 M sodium (NaCl or NaHCO3) and between pH 7.3 and 8.4. Batch experiments revealed that inhibition of MT degradation started at sodium (both NaCl and NaHCO3) concentrations exceeding 0.8 M. Sulfide inhibited MT degradation already around 3 mM (pH 8.3)