Optimization and modelling of dark fermentative hydrogen production from cheese whey by Enterobacter aerogenes 2822 Raman Rao, Nitai Basak * Department of Biotechnology, Dr. B R Ambedkar National Institute of Technology Jalandhar, 144011, India highlights Box Behnken design matrix was used for setting up experimental conditions. Fermentation experiment in 2 L double walled cylindrical bioreactor. Response surface analysis was used to depict the results. Optimum total carbohydrate concentration in cheese whey ¼ 32.5 g L 1 , temp. ¼ 31 C and pH ¼ 6.5. Experimental and predicted bioH 2 production rate were 24.7 mL L 1 h 1 and 23.2 mL L 1 h 1 respectively. Mathematical models for H 2 production gave adequate simulation with experimental values. article info Article history: Received 7 August 2020 Received in revised form 13 October 2020 Accepted 17 October 2020 Available online xxx Keywords: Dark fermentation Bioreactor Cheese whey Box Behnken design Biohydrogen production rate abstract In India, annually about 3.3e5 million tons of cheese whey is produced which may causes serious problems for the environment if left untreated. In this study, pretreated cheese whey was utilized to produce hydrogen via dark fermentation by Enterobacter aerogenes 2822 cells in 2 L double walled cylindrical bioreactor having working volume of 1.5 L. Effect of change in total carbohydrate concentration in cheese whey (CW TC , 20e45 g L 1 ), tem- perature (T, 25e37 C) and pH (5.5e7.5) was investigated on volumetric hydrogen produc- tion rate (VHPR) using Box Behnken design (BBD). Experimental VHPR of 24.7 mL L 1 h 1 was attained at an optimum concentration of 32.5 g L 1 CW TC , 31 C T and 6.5 pH, which was in good correlation with predicted rate of 23.2 mL L 1 h 1 . Mathematical models based on Monod and logistic equations were developed to describe the kinetics of substrate consumption and growth profile of E. aerogenes 2822 under optimum conditions. While for the modelling of fermentative hydrogen production in batch mode, Modified Gompertz equation and Leudeking-Piret models were used which gave proper simulated fitting. These results will add significant values to cheese whey by converting it into a clean form of bioenergy. © 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. * Corresponding author. E-mail addresses: basakn@nitj.ac.in, basakn812@yahoo.com (N. Basak). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (xxxx) xxx https://doi.org/10.1016/j.ijhydene.2020.10.142 0360-3199/© 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article as: Rao R, Basak N, Optimization and modelling of dark fermentative hydrogen production from cheese whey by Enterobacter aerogenes 2822, International Journal of Hydrogen Energy, https://doi.org/10.1016/j.ijhydene.2020.10.142