Effect of thermal pretreated organic wastes on the dark fermentative hydrogen production using mixed microbial consortia

The present study investigates the effect of thermal pretreated organic waste as a feedstock for the dark fermentative hydrogen (H-2) production. Acidogenic mixed consortia was used for H-2 production from starchy wastewater supplemented with groundnut de-oiled cake (GDOC). Physicochemical changes in GDOC after pretreatment were analyzed by using SEM, XRD and FTIR spectra. Maximum cumulative H-2 production and H-2 yield of 3.24 L L-1 and 12.05 mol H-2 kg(-1) CODremoved, respectively were achieved using the pretreated feedstock, which is 20% higher than that of the untreated one. Several kinetic models such as Logistic model, first order reaction kinetics, Pirt model, modified Gompertz model and Luedeking-Piret model were used to find out the effect of pretreatment on the kinetic parameters. Material analysis indicated that the fermentation was dominated by butyric acid pathway. Gaseous energy recovery was improved by two folds after the pretreatment. This is the first attempt to analyze the effect of thermal pretreatment of feedstock on different kinetic parameters associated with dark fermentation.

Automated summary

This study found that thermal pretreated organic waste can be used as an effective feedstock for dark fermentative hydrogen production, achieving higher H-2 production and yield. Various kinetic models were used to analyze the effect of pretreatment, and it was shown that gaseous energy recovery was improved by two folds.