Biological sludges generated ...
Published by Tom Mathews, Engineering Manager
Biological sludges generated by activated sludge treatment of human wastes may be land applied. Generally this material has limited value as a fertilizer because the nutrient concentrations are low. The sludge may be burned as fuel, but the resulting fuel value is also low. Sludge may also be composted although this process involves a higher processing cost. There are some newer technologies that are able to remove the nitrogen and phosphorus from sludge.