Wastewater - Solids Management: Digestion Process


Michigan Environmental Education Curriculum
Wastewater Treatment

Anaerobic digestion is a two-step process. In the first step, bacteria and sludge are mixed together in a heated tank called a digester. This is where the biological activity takes place and biodegradable organic matter is broken down producing gases and inert organic matter. The sludge is then delivered to the second step. This digester is not mixed and the sludge separates with gases at the top of the digester, liquid in the middle and solids on the bottom. Gases that have risen to the top are collected and burned. The liquid is returned to the beginning of the plant to be treated again. Solids are sent to the next step for dewatering.

Alt | Win

Start > Title > Site Map > Credits > Glossary > Help
Michigan Tech > Tech Alive > Series Index > Michigan Environmental Education Curriculum > Module Index > Water