Abstract
The oligochaete worm Nais elinguis was counted during a year and a half in a full-scale, completely mixed, municipal activated sludge plant consisting of four aeration tanks connected in parallel. Simultaneously the operating variables, i.e. effluent quality, energy costs in kWh for oxygen supply in the aeration tanks, and sludge-disposal were measured. The number of worms varied both seasonally and among the aeration tanks. A major worm bloom resulted in a low sludge volume-index, lower energy consumption for oxygen supply expressed in kWh and, depending on the temperature, less sludge-disposal. The worms had no influence on the effluent quality.
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Ratsak, C.H. Effects of Nais elinguis on the performance of an activated sludge plant. Hydrobiologia 463, 217–222 (2001). https://doi.org/10.1023/A:1013124212793
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DOI: https://doi.org/10.1023/A:1013124212793