Sewage sludge treatment
（重定向自Sludge treatment）
![Dried, anaerobically digested sludge.](/Images/godic/202502/11/Anaerobic_digestate0543.JPG")
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![Schematic of a belt filter press to dewater sewage sludge. Filtrate is extracted initially by gravity, then by squeezing the cloth through rollers.](/Images/godic/202502/11/BeltPress.svg0543.png")
![Sludge incineration process schematic (note the emphasis on air quality control).](/Images/godic/202502/11/Blackburn_Meadows_Incineration_Process0543.jpg")
Sewage sludge treatment describes the processes used to manage and dispose of sewage sludge produced during sewage treatment. Sludge is mostly water with lesser amounts of solid material removed from liquid sewage. Primary sludge includes settleable solids removed during primary treatment in primary clarifiers. Secondary sludge separated in secondary clarifiers includes treated sewage sludge from secondary treatment bioreactors.