초록
<P>Methanogenesis inhibition is essential for the improvement of hydrogen (H<SUB>2</SUB>) yield and energy recovery in the microbial electrolysis cell (MEC). In this study, ultraviolet (UV) irradiation was proposed as an efficient method for methanogenesis control in a single chamber MEC. With 30 cycles of operation with UV irradiation in the MEC, high H<SUB>2</SUB> concentrations (>91%) were maintained, while without UV irradiation, CH<SUB>4</SUB> concentrations increased significantly and reached up to 94%. In the MEC, H<SUB>2</SUB> yields ranged from 2.87 ± 0.03 to 3.70 ± 0.11 mol H<SUB>2</SUB>/mol acetate with UV irradiation and from 3.78 ± 0.12 to 0.03 ± 0.004 mol H<SUB>2</SUB>/mol acetate without UV irradiation. Average energy efficiencies from the UV-irradiated MEC were 1.5 times of those without UV irradiation. Energy production from the MEC without UV irradiation was a negative energy yield process because of large amount of CH<SUB>4</SUB> produced over time, which was mainly attributable to cathodic hydrogenotrophic methanogenesis. Our results clearly showed that UV irradiation could effectively inhibit methanogenesis and improve MEC performance to produce H<SUB>2</SUB>.</P><P><B>Graphic Abstract</B><BR><IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/esthag/2014/esthag.2014.48.issue-17/es501202e/production/images/medium/es-2014-01202e_0005.gif'></P>