Hydrogen gas production from glucose and its microbial kinetics in anaerobic systems

The acidogenic phase of a continuous stirred tank reactor (CSTR) inoculated with well acclimated sludge will produce a substantial amount of hydrogen gas and steady state microbial biomass. Hydrogen production of more than 65% was observed at high dilution rate and 71% at low dilution rate. Gas production rate of more than 10 l/day was also observed from the chemostat reactors. The true yield (Yt) value was 0.625 g.VSS/g.COD-utilized and the kd value was 0.41 hr-1. Sample sludge (cell) from chemostat reactors was then collected at steady state and small amount was inoculated into small vials. Many sets of vials were prepared and all were filled up by different concentrations of glucose and growth medium with the same proportion. The vials were treated as batch culture of the mixed microorganisms, incubated at 30 degrees C and put on a rotating shaker with 130 osc.min.-1. The VSS values analyzed on the vials sample at predetermined time intervals will provide the data for the inhibitory constants determinations. From the available kinetics parameters and inhibitory model equation, graph fittings computations were done. The inhibitory model its to some degree on the experimental data. These findings confirmed the inhibitory effects of glucose concentrations and the ability to recover hydrogen gas from organic substances at certain predetermined concentrations. (C) 1997 IAWQ. Published by Elsevier Science Ltd.