Continuous H2 production by anaerobic mixed microflora in membrane bioreactor

The characteristics of H2 production by anaerobic mixed microflora in a submerged membrane bioreactor (MBR) were investigated. For comparative purposes, a continuous stirred tank reactor (CSTR) was operated in parallel under the same conditions. The experimental results showed that 35-day stable and continuous H2 fermentation was successfully achieved, the MBR revealing an H2 content of 51% and the CSTR, 58%. No methane gas was detected during the experiments for the long solids retention time (SRT) of 90 days. The MBR’s H2 production rate was 2.43–2.56 l H2 l−1 d−1, which was about 2.6 times higher than that (0.95–0.97 l H2 l−1 d−1) of the CSTR, reflecting the MBR’s higher H2 productivity.