Question

pH favourable for fermentation in biogas plant is

• A. $4-5$
• B. $5-6$
• C. $6.8-7.2$
• D. $7.6-8.4$

Answer 1

The correct option is C $6.8-7.2$

Fermentation in biogas plant is carried out by anaerobic bacteria known as methanogens. Optimum pH at which methanogenic bacteria are active is about 6.8 - 8.5. Methane production occurs properly at a pH range of 7.0- 8.0. The pH range at which a fermenter in biogas plant operates is about 6.8- 7.5. pH drops in the fermenter when there is accumulation of fatty acids that are not further broken down into carbon dioxide and water.

So, the correct answer is '6.8- 7.2'.