Question

6 The sludge is treated in a waste water treatment plant by
a. Chlorination
b. Anaerobic bacteria
c. Filtration
d. Aeration​

Answer 1

$The \: Answer \: is \: Anaerobic \\ bacteria$

Answer 2

The answer is option b:

Explanation:

b. Anaerobic bacteria

• Mesophilic anaerobic digestion (MAD) is another popular method for processing sewage treatment plant sludge.
• The sludge is fed into enormous tanks and stored for at least 12 days to allow the digestion process to complete the four steps required for sludge digestion.
• Incineration can be used to dispose of biological sludge;
• the carbon, nitrogen, and sulphur are released as gaseous by-products,
• while the inorganic portion is left as ash.