Change language Go to Italian Version


>List all the bibliography
Monitoring denitrification by means of pH and ORP in continuous-flow conventional activated sludge processes
Authors L. Luccarini · D. Pulcini · D. Sottara · R. Di Cosmo · R. Canziani  Year 2017
Pubblication type Paper International Journal with referee
Abstract Indirect signal analysis (pH, ORP and DO) are often used in monitoring and control of SBRs (Sequencing Batch Reactors), where operating conditions can be clearly identified during the various cyclic phases. Only few studies applied this methodology to control continuous flow plants, as it is much more difficult to identify operating conditions because of continually variable inflow characteristics.
This work applied indirect signal analysis to control pre-denitrification in continuous-flow activated sludge processes: (i) a laboratory-scale plant, fed with synthetic wastewater, simulating real municipal wastewater and (ii) a pilot-scale plant, fed with real sewage. Three different ranges of ORP values identify three operational conditions of the denitrification process. (1) ORP > 0 mV means that nitrates and/or nitrites are present, possibly due to a low C/N ratio. (2) -50 < ORP < -200 mV is typical of normal operating conditions, that is with a balanced C/N ratio. (3) ORP < -350 mV means that oxidized nitrogen load is too low or that C/N exceeds the stoichiometric ratio. The trend of pH, instead, points out if and how the process is evolving from one to another operating condition. The correlation between pH and ORP signals (as well as their derivatives) allows to restore normal operating conditions by acting on the internal recycle flow-rate. Improved denitrification process ensures lower effluent nitrate concentration, and reduce external carbon dosage to achieve stricter nitrogen limits.
Volume 61 January 2017
Repository reference DI212-012
Research unit X-LAB
Keywords Denitrification monitoring; ORP signal; pH signal; pre-denitrification systems
LastUpdate 21/05/2018
Related research topics
Code Topic Description
2.5.1 Trattamento reflui Civili
3.5 Decision support systems

impact factor Falso

back to Home page






logo rete alta tecnologia emilia romagna

Il Laboratorio ha realizzato progetti finanziati dai Fondi europei della Regione Emilia-Romagna e dal Fondo per lo sviluppo e la coesione
Termini di uso
Politica sulla Privacy

Share this page with

LinkedIN share Facebook share share
Dichiarazione di accessibilità 6d66ae69-c6fd-4cb9-b536-be3fdfb0144c