Bioresource Technology, Vol.159, 55-63, 2014
Organic loading rate impact on biohydrogen production and microbial communities at anaerobic fluidized thermophilic bed reactors treating sugarcane stillage
This study aimed to evaluate the effect of high organic loading rates (OLR) (60.0-480.00 kg COD m (3) d (1)) on biohydrogen production at 55 degrees C, from sugarcane stillage for 15,000 and 20,000 mg COD L (1), in two anaerobic fluidized bed reactors (AFBR(1) and AFBR(2)). It was obtained, for H-2 yield and content, a decreasing trend by increasing the OLR. The maximum H-2 yield was observed in AFBR(1) (2.23 mmol g CODadded1). The volumetric H-2 production was proportionally related to the applied hydraulic retention time (HRT) of 6, 4, 2 and 1 h and verified in AFBR1 the highest value (1.49 L H-2 h (1) L (1)). Among the organic acids obtained, there was a predominance of lactic acid (7.5-22.5%) and butyric acid (9.4-23.8%). The microbial population was set with hydrogen-producing fermenters (Megasphaera sp.) and other organisms (Lactobacillus sp.). (C) 2014 Elsevier Ltd. All rights reserved.