模拟微通道光生物反应器内光合细菌的成膜及产氢特性

引言 氢气由于具有清洁、热值高、来源广泛等优点被认为是未来理想的能量载体1-2].生物制氢可以在不消耗一次能源的同时产生氢气,是未来研究与开发清洁能源的一个重要途径3].光合细菌可以吸收光能、降解有机废水、产生氢气,能够将氢能开发和有机废物治理有机结合起来,具有广阔的发展前景4-5].

Film formation and hydrogen production performance of photosynthetic bacteria in simulating microchannels photo-bioreactor

In order to understand the micro-behavior and mass transfer of photosynthetic bacteria (PSB)in an immobilized granule, a visualized microchannels photo-bioreactor was designed to observe the adsorption and film forming of PSB named as Rhodopseudomonas palustris CQK 01. And the effects of substrate concentration and flow rate on hydrogen production and substrate degradation of microchannels photo-bioreactor were investigated. The results showed that the PSB behavior in the microchannels can be divided into four stages: initial diffusion and adsorption, diffusion-adsorption and initial splitting and reproducing of bacteria, dividing-increasing and morphological transformation, and gathering and biofilm forming. With the increase of substrate concentration and flow rate, the rate and yield of hydrogen producing rised first and then fell down, but the substrate conversion monotonically went up with its rate slowed down. The substrate degradation efficiency increased first and then decreased with increase of substrate concentration,and reduced with increase of solution flow rate. At higher substrate concentration and flow rate, substrate inhibition and the loss of biofilm were the main reasons for lower rate and yield of hydrogen production. In the range of present experiments, the optimum substrate concentration and flow rate were 50mmol·L^-1 and 2.1ml·h ^-1 respectively, the maximum rate and yield of hydrogen production were 2.4mmol·(g cell dry mass)^-1 ·h ^-1 and 0.78 mol H₂·(mol sub)^-1 respectively.