Characteristics of a biofilm photobioreactor as applied to photo-hydrogen production

The application of a cell immobilization technique to a biofilm-based photobioreactor was developed to enhance its photo-hydrogen production rate and light conversion efficiency. Rhodopseudomonas palustris CQK 01 was initially attached to the surface of packed glass beads to form a biofilm in this experiment. Then, the biofilm photobioreactor (BPBR) was illuminated by light-emitting diodes with light wavelengths of 470, 590 and 630 nm and hydrogen was evolved with glucose being the sole carbon source. Under the illumination condition of 5000 lux illumination intensity and 590 nm wavelength, the BPBR showed good hydrogen production performance: the hydrogen production rate was 38.9 ml/l/h and light conversion efficiency was 56%, while the hydrogen yield was 0.2 mol H2/mol glucose. Furthermore, results show that the highest hydrogen production rate and glucose removal rate were obtained when the glucose concentration is 0.12 M, the optimal pH 7 and optimal temperature of influent liquid 25 °C.