Calculation of residence time distribution from tracer recycle experiments

Battaglia, A.; Fox, Peter; Pohland, Frederick G.

doi:10.1016/0043-1354(93)90093-w

Cited by 14 publications

(1 citation statement)

References 2 publications

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“…Although several chemical, optical and radioactive tracers have been employed to investigate RTD in wastewater treatment plants, properties like high detection sensitivity and high selectivity, which facilitate in-situ measurements and the online collection of data, make radiotracers a superior choice in terms of the RTD analysis of large-scale industrial systems. The advantages of using radiotracers in RTD studies of full-scale industrial processes have been discussed in detail by many researchers [10][11][12][13][14][15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Radiotracer investigation of a pulp and paper mill effluent treatment plant

et al. 2017

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The pulp and paper industry is highly dependent on water for most of its processes, producing a significant amount of wastewater that should be treated to comply with environmental standards before its discharge into surface-water reservoirs. The wastewater generated primarily consists of substantial amounts of organic, inorganic, toxic and pathogenic compounds in addition to nutrients, which are treated in an effluent treatment plant that often combines primary, secondary, tertiary and advanced treatments. However, the treatment methods vary from industry to industry according to the process utilized. The effective performance of effluent treatment plants is crucial from both environmental and economic points of view. Radiotracer techniques can be effectively used to optimize performance and detect anomalies like dead zones, bypassing, channelling, etc. in wastewater treatment plants. Experiments on the distribution of residence time were performed on the aeration tank and secondary clarifier of a full-scale pulp and paper mill to study the flow behaviour as well as locate system anomalies and hence evaluate the performance of the treatment plants using the radiotracer I-131. The convolution method was applied to model the system with an imperfect impulse radiotracer input. The aeration tank was working efficiently in the absence of any dead zones or bypassing. Various hydrodynamic models available in the literature were applied on the aeration tank and secondary clarifier to obtain the hydraulic representation of the systems.

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Section: Introductionmentioning

confidence: 99%

Radiotracer investigation of a pulp and paper mill effluent treatment plant

et al. 2017

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Application of residence time distribution technique to the study of the hydrodynamic behaviour of a full‐scale wastewater treatment plant plug‐flow bioreactor

Olivet

Valls

Gordillo

et al. 2005

J of Chemical Tech & Biotech

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The hydrodynamic behaviour of a full-scale wastewater treatment plant (WWTP) bioreactor treating municipal wastewater, situated in Granollers (Barcelona, Spain), has been studied by means of a residence time distribution (RTD) technique using lithium (chloride) as tracer. The bioreactor studied is designed to work as a plug-flow reactor and it is divided into two independent lanes (1 and 2), each one composed of four compartments in series resulting in a total volume of 3970 m 3 per lane. During the RTD experiments, working flow was 1000 m 3 h −1 per lane, which implied an ideal mean residence time of 3.97 h. When a lithium chloride tracer was injected in the bioreactor, both lanes showed a similar highly non-ideal hydrodynamic behaviour, which had an important effect on the reactor's performance. This global RTD was complemented by means of local RTDs in different locations of the bioreactor in order to determine qualitatively the reactor's mixing regime. Different non-ideal models (namely axial dispersion, tanks-in-series and some simple compartment models) have been tested for the modelling of the experimental RTD. The best model fitting RTD data for Lanes 1 and 2 was a configuration consisting of four mixed tanks in series. The RTD study proposed in this work will permit improvement of the reactor's mixing performance, which is of special interest in future projects including simultaneous removal of carbon, nitrogen and phosphorus.

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