Activated sludge.
D001673:Biodegradation, Environmental; D007220:Industrial Waste; D009584:Nitrogen / Q000378:metabolism; D010101:Oxygen Consumption; D010758:Phosphorus / Q000302:isolation & purification; D012722:Sewage; D014871:Water Microbiology
D007220:Industrial Waste; D012722:Sewage; D010758:Phosphorus; D009584:Nitrogen