Role of Nitrogen in Activated Sludge Process

by Yeun C. Wu, Asst.Prof.; Dept. of Civ. and Environmental Engrg., Univ. of Pittsburgh, Pittsburgh, Pa.,

Serial Information: Journal of the Environmental Engineering Division, 1976, Vol. 102, Issue 5, Pg. 897-907

Document Type: Journal Paper


Study of the effect of nitrogen limitation on metabolic activities of activated sludge has been conducted by using a completely mixed continuous flow bench-scale activated sludge unit. The system was operated at various dilution rates with and without cellular recycle, and was maintained at a constant temperature 26—1°C and pH of 6.5. The results show that the concentration of nitrogen in the feed will significantly affect the contents of sludge phosphorus, sludge protein, and carbohydrate as well as the morphological configuration of sludge organisms. However, the results obtained from the system with cellular recycle show that the substrate utilization rate and sludge yield coefficient are independent of nitrogen concentration in the feed. The rate of oxygen utilization is higher in the nitrogen-rich activated sludge system than the nitrogen-deficient activated sludge system, but the endogenous respiration rate constant is identical in both systems.

Subject Headings: Nitrogen | Activated sludge | Recycling | Benchmark | Dilution | Temperature effects | pH | Phosphorus

Services: Buy this book/Buy this article


Return to search