Improving EGSB reactor performance for simultaneous bioenergy and organic acid production from cheese whey via continuous biological H production.

OBJECTIVES

To evaluate the influence of hydraulic retention time (HRT) and cheese whey (CW) substrate concentration (15 and 25 g lactose l) on the performance of EGSB reactors (R15 and R25, respectively) for H production.

RESULTS

A decrease in the HRT from 8 to 4 h favored the H yield and H production rate (HPR) in R15, with maximum values of 0.86 ± 0.11 mmol H g COD and 0.23 ± 0.024 l H h l, respectively. H production in R25 was also favored at a HRT of 4 h, with maximum yield and HPR values of 0.64 ± 0.023 mmol H g COD and 0.31 ± 0.032 l H h l, respectively. The main metabolites produced were butyric, acetic and lactic acids.

CONCLUSIONS

The EGSB reactor was evaluated as a viable acidogenic step in the two-stage anaerobic treatment of CW for the increase of COD removal efficiency and biomethane production.