keywords ACTIVATED-SLUDGE SYSTEMS AMMONIA-OXIDIZING BACTERIA BIOLOGICAL PHOSPHORUS REMOVAL BULKING DOMINANT POPULATIONS Environmental Sciences Environmental Sciences & Ecology IN-SITU HYBRIDIZATION Life Sciences & Biomedicine MICROTHRIX-PARVICELLA Meteorology & Atmospheric Sciences NITRIFYING BACTERIA PHOSPHATE REMOVAL Physical Sciences SUBSTRATE UPTAKE Science & Technology Water Resources biological nutrient removal ecological engineering filamentous bulking glycogen accumulating organisms nitrifying bacteria phosphorus accumulating organisms