Dissolved Oxygen-Stat Titration Respirometry: Principle of Operation and Validation

Rozzi, A.; Ficara, Elena; Rocco, A.

doi:10.1061/(asce)0733-9372(2003)129:7(602)

Cited by 5 publications

(2 citation statements)

References 21 publications

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“…The application of pH-stat titration to nitrification activity assessment was first proposed by Ramadori et al (1980). As for DO-stat titration, DO concentration is measured by a DO probe and is maintained constant by titrating a solution that contains oxygen (Rozzi et al 2003). Normally, a diluted hydrogen peroxide solution is used as titrant.…”

Section: The Automatic Ph/do-stat Titrator Prototypementioning

confidence: 99%

Automatic set-point titration for monitoring nitrification in SBRs

Fiocchi

Ficara

Bonelli

et al. 2008

Water Science and Technology

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Nitrification is usually the bottleneck of biological nitrogen removal processes. In SBRs systems, it is not often enough to monitor dissolved oxygen, pH and ORP to spot problems which may occur in nitrification processes. Therefore, automated supervision systems should be designed to include the possibility of monitoring the activity of nitrifying populations. Though the applicability of set-point titration for monitoring biological processes has been widely demonstrated in the literature, the possibility of an automated procedure is still at its early stage of industrial development. In this work, the use of an at-line automated titrator named TITAAN (TITrimetric Automated ANalyser) is presented. The completely automated sensor enables us to track nitrification rate trend with time in an SBR, detecting the causes leading to slower specific nitrification rates. It was also possible to perform early detection of toxic compounds in the influent by assessing their effect on the nitrifying biomass. Nitrifications rates were determined with average errors+/-10% (on 26 tests), never exceeding 20% as compared with UV-spectrophotometric determinations.

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Section: The Automatic Ph/do-stat Titrator Prototypementioning

confidence: 99%

Automatic set-point titration for monitoring nitrification in SBRs

Fiocchi

Ficara

Bonelli

et al. 2008

Water Science and Technology

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“…, dpH/dt = 0) to occur on the pH profile was calculated. To simplify calculation of the respiration rate of the activated sludge, the respirometic measurement was carried out under static gas conditions, which is referred to as a closed respirometer [20,24]. The feasibility of the strategy was first evaluated by performing experiments in a batch mode with toxic chemicals.…”

Section: Introductionmentioning

confidence: 99%

A DO- and pH-Based Early Warning System of Nitrification Inhibition for Biological Nitrogen Removal Processes

Hong

Choi

Lim

et al. 2012

Sensors

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In Korea, more than 80% of municipal wastewater treatment plants (WWTPs) with capacities of 500 m3·d−1 or more are capable of removing nitrogen from wastewater through biological nitrification and denitrification processes. Normally, these biological processes show excellent performance, but if a toxic chemical is present in the influent to a WWTP, the biological processes (especially, the nitrification process) may be affected and fail to function normally; nitrifying bacteria are known very vulnerable to toxic substances. Then, the toxic compound as well as the nitrogen in wastewater may be discharged into a receiving water body without any proper treatment. Moreover, it may take significant time for the process to return back its normal state. In this study, a DO- and pH-based strategy to identify potential nitrification inhibition was developed to detect early the inflow of toxic compounds to a biological nitrogen removal process. This strategy utilizes significant changes observed in the oxygen uptake rate and the pH profiles of the mixed liquor when the activity of nitrifying bacteria is inhibited. Using the strategy, the toxicity from test wastewater with 2.5 mg·L−1 Hg2+, 0.5 mg·L−1 allythiourea, or 0.25 mg·L−1 chloroform could be successfully detected.

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