Sludge treatment

摘要

Municipal sludge is converted from an environmental problem into soil amendment and electricity. Methane, produced in an anaerobic digester (2), is used partially to generate electricity and partially to dry the concentrated sludge in a rotary dryer (7). Excess heat from the dryer is used to maintain the temperature in the digester at approximately 105 DEG to 130 DEG F. Heavy metals are removed so that the dried sludge can be safely used as a soil amendment.