Question

How is activated sludge dried?

Answer 1

1. Sludge is human waste (such as faeces) that is left over after sewage treatment. It is utilized to make biogas and manure because it's organic waste.
2. Sludge settles to the bottom of the sedimentation tank and is collected by a scraper. It is moved to a digester, which is a separate tank where anaerobic bacteria degrade it.
3. The biogas generated during the process can be utilized as a fuel or to generate energy.
4. The clarified water from the sedimentation tank is passed into the aeration tank.
5. The suspended microorganisms settle to the bottom of the aeration tank as activated sludge. Water makes up to 97 percent of activated sludge.
6. Sand drying beds or machines are used to remove the water. Dried sludge is utilized as manure.