Abstract
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 the strong variations in the BOD5/NO3-N ratios and the unexpected abnormal accumulation of dissolved oxygen during denitrification when the BOD5 load is low. These phenomena cause inhibitory effects and BOD5 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.
Highlights
The influence of variations in sewage quality on the wastewater treatment plants (WWTPs) performance of biological processes has been studied since the 70s
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
Large variations in the quality of raw sewage, which are typical of small communities, make high biological denitrification efficiencies (η ≥ 90%) hard to achieve
Summary
The influence of variations in sewage quality on the WWTP performance of biological processes has been studied since the 70s. The raw sewage of small communities is characterized by great variations in flow rates and quality, which affect the entire treatment. This is significant for biological denitrification, where the typical removal efficiency achieved in medium-large activated sludge plants without primary sedimentation (about 90%) is very difficult to obtain. This paper deals with the influence of the great diurnal variation in sewage quality on the denitrification performance of a WWTP serving a community of 15,000 inhabitants in the Po river basin. An experimental study on a pilot plant was carried out, monitoring both influent and effluent main parameters through both daytime single and continuous samplings
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
