Dark fermentative hydrogen gas production from molasses using hot spring microflora

This study reports hydrogen gas (H-2) production from molasses by hot spring microflora in three stages. During the first two stages most convenient temperature, inoculation percentage (INP) ensuring the highest H-2 yield and rate were determined using suspended culture. Then, H-2 was produced by the same culture immobilized on porous ceramic rings at three different hydraulic retention times. For the suspended culture experiments, the most effective H-2 production resulting 202.32 mL H-2/g COD was obtained at 37 & DEG;C with 10 INP. The highest H-2 formation of 534.35 mLH(2)/d was realized for the biofilm culture at 0.53 day hydraulic retention time and H-2 production using hot spring microflora in biofilm form was found to be promising. The pH of the experiments remained stable around 5.5-6.5 without a requirement for pH adjustment during the fermentation.& nbsp;(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.