Activated sludge.
D001331:Automation; D004467:Economics; D007220:Industrial Waste / Q000032:analysis*; D008433:Mathematics; D008722:Methods; D008962:Models, Theoretical; D010100:Oxygen; D011871:Radiology; D012722:Sewage; D013696:Temperature; D014116:Toxicology; D014871:Water Microbiology; D014876:Water Pollution / Q000517:prevention & control*
D007220:Industrial Waste; D012722:Sewage; D010100:Oxygen