A survey of filamentous organisms at the deer Island treatment plant
Abstract The Deer Island Treatment Plant (DITP) treating both domestic and industrial wastewater, has a peak flow capacity of up to 1270 million gallons per day (MGD) (3342 m3 min−1). The DITP contains a Pilot Plant, which consists of two identical pure oxygen activated sludge treatment trains, each with a maximum capacity of 1 MGD (2.63 m3 min−1) to simulate the maximum flow of the full size facility. This study documents the community of filamentous organisms living in the activated sludge under various operational conditions in the Pilot Plant. Sixteen types of filamentous organisms were identified. The major filamentous organisms present in the Pilot Plant were Type 1701, Type 0041, Sphaerotilus natans, Microthrix parvicella, and Nocardia sp. Nocardia sp. was quite dominant in the early stages of the experimental period during high ambient temperatures (summer), indicating that temperature is one determining factor in the distribution of Nocardia sp. Thiothrix sp. was very sensitive to the dissolved oxygen (DO) level, with low DO values favoring the growth of the organisms. Microbiological observations made during the start‐up and stable operation of the full‐scale secondary treatment plant (maximum capacity 780 MGD) are also reported. No dominant filamentous species existed during the start‐up period. Type 0803 and Type 1701, indicators of low oxygen level for the applied food to microorganism ratio, confirmed the low DO conditions of activated sludge tanks.
Manual on the causes and control of activated sludge bulking and foaming
Solids Separation Problems. Microscopic Examination of Activated Sludge with Special Reference to Floc Characteristics and Filamentous Organism Characterization. Control of Activated Sludge Bulking. Activated Sludge Foaming. Bibliography and References. Index.
Scum actinomycetes in sewage treatment plants. I. Growth kinetics of Nocardia amarae in chemostat culture.
Abstract The scum actinomycete Nocardia amarae was grown in batch culture and in chemostat culture on a fructose-peptone-yeast extract substrate. Chemostat growth is modeled with a two-substrate Monod equation incorporating 6 parameters which include maximum growth, kinetic constants for substrate and oxygen, cell yield and wall growth. These parameters were identified by numerically optimizing the fit. Among these parameters μ max = 0.087 ± 0.0075 h −1 and K s = 675 ± 124 mg l −1 , a value much higher than found for other activated sludge bacteria. The results are compared with findings of other researches for other sludge bacteria. Different growth strategies of these organisms are discussed.