生物膜法光发酵制氢的研究现状与展望

Research status and prospect of photo⁃fermentative hydrogen production with biofilm formation

21世纪被誉为氢能世纪.光发酵制氢作为绿色可持续生物制氢方式的一种,可以利用独特的光合系统固定太阳能,并利用有机物产生清洁能源氢气,因而受到广泛关注.但光发酵细菌凝集力差、底物转化效率和光能利用率低导致产氢效能下降,从而阻碍了光发酵制氢的发展.光发酵细菌可以通过形成生物膜而被有效固定,进而增加反应器内光发酵细菌的生物持有量,提高光发酵细菌对不利环境的抵抗力;同时,光发酵细菌形成生物膜后可以调控产氢细菌新陈代谢和生理活性使其更利于产氢.其中,光发酵生物膜反应器的设计尤为重要,尤其是反应器内光源的均匀分配对于光发酵制氢是一项关键因素,需要对光源设计、空间摆放和遮光性进行综合分析和设计;其次,需要考虑载体性质和载体安装以充分吸附光发酵细菌并形成生物膜;同时,结合未来可持续绿色发展的需求,光发酵生物膜反应器设计需要逐步过渡到以室外环境作为常规环境和太阳作为光源.尽管光发酵生物膜制氢前景良好,但目前对于光发酵生物膜反应器和制氢机制的研究仍然不够充分,需要更加深入地探索和优化以突破光发酵制氢的瓶颈,推动氢能行业的发展.

Twenty⁃first century will be the century of hydrogen energy.Photo⁃fermentative hydrogen production is one green and sustainable alternative for biological hydrogen production.It can fix solar energy,degrade organic matters and generate hydrogen via the unique photosystem,thus it draws amounts of attention.However,development of photo⁃fermentative hydrogen production is facing the bottleneck because of the low hydrogen production and light utilization efficiency due to the poor flocculation and substrate utilization ability.Biofilm can stimulate the photo⁃fermentative hydrogen production through the increased biomass due to the fixation.Besides,biofilm could regulate photo⁃fermentative bacteria in reactor to possess better hydrogen production ability and higher resistance to unbenefited environment.At the same time,design of photo⁃fermentative biofilm reactor requires special consideration.Firstly,the uniform distribution of light in the reactor is a key factor for photo⁃fermentative hydrogen production.Therefore,light source,space distribution and shading need to be considered comprehensively.Then the carrier properties and the introduction of carrier should support absorption of bacteria and biofilm formation.Last,basing on the sustainable green development in the future,photo⁃fermentative biofilm reactors need to be designed for outdoor environment with sun as the light source.Although photo⁃fermentative biofilm expresses superior properties for hydrogen production,the referenced research on inner mechanism is still sparse.Further researches are needed to break through the bottleneck of photo⁃fermentative hydrogen production and promote the development of hydrogen energy industry in China.