A kinetic study of biohydrogen production from glucose, molasses and cheese whey by suspended and attached cells of Thermotoga neapolitana

摘要

Batch tests of H_2 production from glucose, molasses and cheese whey by suspended and immobilized cells of Thermotoga neapolitana were conducted to develop a kinetic model of the process. H_2 production was inhibited by neither H_2 (up to 0.7mgL~(-1)) nor O2 (up to 0.2mgL~(-1)). The H_2 specific rates obtained at different substrate concentrations were successfully interpolated with Andrew's inhibition model. With glucose and molasses, biofilms performed better than suspended cells. The suspended-cell process was successfully scaled-up to a 19-L bioreactor. Assays co-fed with molasses and cheese whey led to higher H_2 productivities and H_2/substrate yields than the single-substrate tests. The simulation of the suspended-cell continuous-flow process indicated the potential attainment of H_2 productivities higher than those of the batch tests (up to 3.6mmol_(H2)h~(-1)L~(-1) for molasses and 0.67mmol_(H2)h~(-1)L~(-1) for cheese whey) and allowed the identification of the optimal dilution rate.