초록
<P><B>Abstract</B></P> <P>The aim of this study was to evaluate the influence of C/P and C/N ratios on the production of hydrogen and ethanol in four anaerobic fluidized bed reactors: R1 (C/N = 100), R2 (C/N = 150), R3 (C/N = 200), and R4 (C/N = 250). The hydraulic retention time (HRT) was maintained at 2 h, and the C/P ratios varied from 300 to 1100. Reactors were filled with grounded tire and fed with synthetic substrate containing glucose (5000 mg L<SUP>−1</SUP>). The effluent pH was around 3.7. The highest values for hydrogen yield (HY) and hydrogen production rate (HPR) were obtained at a C/P = 700 ratio in all reactors. The best performance was achieved at R3 (C/N = 200): HY of 0.76 mol H<SUB>2</SUB> mol<SUP>−1</SUP> glucose and HPR of 0.70 L h<SUP>−1</SUP> L<SUP>−1</SUP>. The highest value for ethanol yield was obtained at C/P = 700 in R1 (1.5 mol EtOH mol<SUP>−1</SUP> glucose). Ethanol- and hydrogen-producing fermenters, such as <I>Ethanoligenens</I> sp. and <I>Clostridium</I> sp. were identified by molecular analysis. <I>Lactobacillus</I> sp. was also identified in this study.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The C/P and C/N ratios influenced the production of H<SUB>2</SUB> and ethanol in anaerobic fluidized bed reactors. </LI> <LI> An optimum hydrogen yield was 0.76 mol H<SUB>2</SUB> mol<SUP>−1</SUP> glucose at C/N = 200 and C/P = 700. </LI> <LI> The C/P ratios caused significant changes in the bacterial communities in three of the reactors. </LI> <LI> Ethanol was the primary product in almost all the ratios of C/P. </LI> <LI> <I>Ethanoligenens</I> sp. and <I>Clostridium</I> sp. were the dominant bacteria. </LI> </UL> </P>