National Engineering Research Centre for Biochemistry, Nanjing University of Technology, Nanjing 210009, People's Republic of China.
Water Sci Technol. 2010;61(3):721-7. doi: 10.2166/wst.2010.900.
The single-chamber membrane-less MEC exerted much better hydrogen production performance while given higher applied voltages than it did at lower. High applied voltages that could shorten the reaction time and the exposure of anode to air for at least 30 min between cycles can significantly suppress methanogen and increase hydrogen production. At an applied voltage of 1.0 V, a hydrogen production rate of 1.02 m(3)/m(3)/day with a current density of 5.7 A/m(2) was achieved. Cathodic hydrogen recovery and coulombic efficiency were 63.4% and 69.3% respectively. The hydrogen concentration of mixture gas produced of 98.4% was obtained at 1.0 V, which was the best result of reports. The reasons that such a high hydrogen concentration can be achieved were probably the high electrochemical activity and hydrogen production capability of the active microorganisms. Increase in substrate concentrations could not improve MEC's performance, but increased the reaction times. Further, reactor configuration and operation factors optimisation should be considered to increase current density, hydrogen production rate and hydrogen recovery.
单室无膜 MEC 在施加较高电压时的产氢性能优于施加较低电压时，这是因为较高的施加电压可以缩短反应时间，并在每个周期之间至少将阳极暴露于空气中 30 分钟，从而显著抑制产甲烷菌并增加产氢量。在 1.0 V 的施加电压下，实现了 1.02 m³/m³/天的产氢速率和 5.7 A/m²的电流密度。阴极氢气回收和库仑效率分别为 63.4%和 69.3%。在 1.0 V 时获得了 98.4%的混合气中氢气浓度，这是报告中的最佳结果。能够达到如此高的氢气浓度的原因可能是活性微生物具有高电化学活性和产氢能力。增加底物浓度不能提高 MEC 的性能，但会增加反应时间。此外，应考虑优化反应器结构和操作因素，以提高电流密度、产氢速率和氢气回收。
