Developing a statistical model to predict hydrogen production by a mixed anaerobic mesophilic culture

摘要

Optimizing the hydrogen (H_2) yield at several initial pH conditions in a mixed batch anaerobic mesophilic culture fed with glucose and linoleic acid (LA) was performed using a three factor three level Box-Benkhen design (BBD). Based on the BBD approach, a statistical model was developed to predict the H_2 yield. The variables considered for the experimental design were the LA concentration, the initial pH and the number of times glucose was added to the culture. The D-optimality method predicted a maximum H_2 yield of 3.49 molH_2 mol glucose~(-1) for cultures fed 1.9 gl~(-1) LA, maintained at an initial pH of 5.15 and received 1.79 glucose additions. The response outcome (H_2 yield of 3.38 ± 0.22 mol -mol glucose~(-1)) at the nearest setting of the experimental factors (2.0 gl~(-1) LA, an initial pH of 5.0 and two glucose additions) was 3.3% less than the predicted maximum value. The model provides a useful approach for predicting H_2 production when H_2 consumers are inhibited in mixed batch anaerobic cultures.