微通道光生物反应器内光合细菌的成膜及产氢特性

For the understanding of photosynthetic bacteria (PSB) behavior and mass transfer in an immobilized granule, a visualized microchannels photobioreactor was designed to observe the adsorption and biofilm formation of PSB named as Rhodopseudomonas palustris CQK 01 in the microchannels. And then the effects of substrate concentration and flow rate of the influent solution were investigated on hydrogen production and substrate degradation of the microchannels photobioreactor. The results showed that the PSB behavior in the microchannels can be divided into four stages, including diffusion and absorption, bacteria reproduction, morphological transformation and biofilm formation. As the substrate concentration and flow rate of the influent solution increased, the hydrogen production rate and hydrogen yield of the photobioreactor increased first and then decreased, while the substrate conversion rate monotonically increased with decreasing slope. The substrate degradation efficiency increased first and then decreased with increasing influent substrate concentration, while reduced with increasing solution flow rate. Substrate inhibition and the loss of biofilm were the main reasons for the lower hydrogen production rate and hydrogen yield under higher substrate concentration and flow rates of the influent solution. In the present experiments, the optimum substrate concentration was 50 mmol / L, the optimum flow rate was 2.1 mL/h, the maximum hydrogen production rate was 2.4 mmol/g cell dry weight/h and the maximum hydrogen yield was 0.48 mol H2/mol sub.