An online-monitored thermophilic hydrogen production UASB reactor for long-term stable operation

摘要

In this study, the H_2 production and chemical oxygen demand (COD) removal performances of a thermophilic upflow anaerobic sludge blanket (UASB) reactor with online monitoring system were investigated. The online monitoring system enabled a rapid monitoring and timely control of the process. As a consequence, high operating stability was achieved despite of the varied hydraulic retention time (HRT) during 310-day operation. The COD efficiency remained at above 98%, and the hydrogen yield fluctuated slightly within the range of 2.42-3.06 mol H_2 mol~(-1) sucrose. Thermophilic H_2-producing granules were successfully cultivated in this reactor, which showed better physical and microbial properties than floe sludge and higher H_2 production rate than mesophilic granules. An analysis of the microbial growth kinetics further demonstrated a possibly higher synthesis and metabolism activity of microbes in the thermophilic granule state.