Influence of Strong Diurnal Variations in Sewage Quality on the Performance of Biological Denitrification in Small Community Wastewater Treatment Plants (WWTPs)

Massimo Raboni, Vincenzo Torretta, Giordano Urbini
2013 Sustainability  
The great diurnal variation in the quality of wastewater of small communities is an obstacle to the efficient removal of high nitrogen with traditional activated sludge processes provided by pre-denitrification. To verify this problem, the authors developed a pilot plant, in which the domestic wastewater of community of 15,000 inhabitants was treated. The results demonstrate that average and peak nitrogen removal efficiencies of over 60% and 70%, respectively, are difficult to obtain because of
more » ... o obtain because of the strong variations in the BOD 5 /NO 3 -N ratios and the unexpected abnormal accumulation of dissolved oxygen during denitrification when the BOD 5 load is low. These phenomena cause inhibitory effects and BOD 5 deficiency in the denitrification process. The results demonstrate the need for a more complex approach to designing and managing small wastewater treatment plants (WWTPs) provided with denitrification than those usually adopted for medium-and large-size plants.
doi:10.3390/su5093679 fatcat:cusx3x7b2fcvtbsz6n672tfdmq