Studies on kinetics of substrate utilization of hydrogen production from wastewater with immobilized cells of photosynthetic bacteria.

The kinetic characteristics of substrate utilization by immobilized cells of Rhodopseudomonas capsulata 386 and Rhodopseudomonas sp. D for H2 production was investigated. The results showed that substrate utilization did not proceed simultaneously with H2 evolution, H2 producing capacity of immobilized cells with agar was higher than that of alginate immobilized cells, but the appearance of maximum H2 producing activity was later than the last one. The kinetics of substrate utilization (glucose) by immobilized cells of strain D followed the first-order reaction, rate constant k value was 1.2 x 10(-2) L/h, analysis of macrokinetics indicated that substrate utilization by immobilized cells in H2 evolution process was governed by biochemical reaction other than diffusion transfer limitation, because of the Thiele modulus were 0.125 and 0.154 for immobilized cells with D = 3.6 mm and 4.4 mm particles, the corresponding effective factor were determined as 0.998 and 0.988, respectively. An immobilized cell bioreactor, fed by glucose and lactate, was employed for continuous H2 evolving system. It was found that hydrogen production were 0.659 L/d and 0.477 L/d in immobilized cells system of strain 386 and D when lactate used as H2 evolving substrate, while the volumetric H2 rate were all up to 1.0 L/L.d.