Civil Engineering - Waste Water Engineering - Discussion

In the second stage of digestion, known as the period of intensive digestion, stabilization and gasification, the more resistant nitrogenous materials, such as the proteins, amino-acids and others, are attacked. The pH value must be maintained from 6.8 to 7.4.

Large volumes of gases with a 65 or higher percentage of methane are produced. Methane is an odourless, highly inflammable gas which can be used as a fuel. The organisms which convert organic acids to methane and carbon dioxide gases are called methane formers. The solids remaining are relatively stable or only slowly putrescible, can be disposed of without creating objectionable conditions and have value in agriculture.

Methane emitted in sewers, not in sludge digestion.

So, it is CO2.

Shouldn't this be Methane? I'm confused. Someone please clarify.

Methane is the correct answer for this question.

Yes, the correct answer is methane up to 75%.

Methane with a percentage of 65-70.

Methane 75%, carbon dioxide 25%.

I think the answer is methane.

The correct answer is Methane.

METHANE is the correct answer.