The following three stages are known to occur in the the biological action involved in the process of sludge digestion:

1. Acid fermentation

2. Alkaline fermentation

3. Acid regression

The correct sequence of theese stages is

- 1
  
  1, 2, 3
- 2
  
  2, 3, 1
- 3
  
  3, 1, 2
- 4
  
  1, 3, 2

Display Comments

Leave a comment

Login at first then you can submit comment. Click here to login.