Effect of pH dynamic control on ethanol-lactic type fermentation (ELTF) performance of glucose

ABSTRACT

This study proposed a new ethanol-lactic type fermentation (ELTF) and explored the optimal control strategy. Using batch experiments, the effects of pH, temperature and organic loading (OL) on ELTF were investigated. The sum of ethanol and lactic acid yield was highest at whole-control pH value of 4.0, 35°C temperature and OL of 33 gCOD/L. To improve ELTF, the dynamic pH control in the long-term CSTR was adjusted at 4.0 (1–28 days), 5.0 (29–44 days) and 4.0 (46–62 days) successively. The high concentration of ethanol and lactic acid was 8190.5 mg/L at 16th day of pH 4.0. At pH of 5.0, the average acidogenesis rate and total concentration of fermentation products increased 111.0% and 128.0%, respectively. Organisms of Lactobacillus and Bifidobacterium were the predominant bacteria in reactor. It can achieve the directional regulation of ELTF and provides parameter support for the application of two-phase anaerobic digestion.

GRAPHICAL ABSTRACT

KEYWORDS:

• Anaerobic fermentation
• dynamic pH control mode
• ethanol-lactic type fermentation
• metabolic pathways
• microbiology community

Acknowledgements

This work was supported by Major Science and Technology Program for Water Pollution Control and Treatment of China (2018ZX07105003, 2017ZX07301004-001-03).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article. The raw data that support the findings of this study are available on request from the corresponding author.

Additional information

Funding

This work was supported by Major Science and Technology Program for Water Pollution Control and Treatment of China: [Grant Numbers (2018ZX07105003)].