Wyniki wyszukiwania - BazTech

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Efektywność reaktorów wielofazowych z osadem czynnym w świetle doświadczeń eksploatacyjnych

Mucha Z.

Logistyka

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2015

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nr 3

3381--3386, CD 1

PL

W artykule przedstawiono wyniki analiz i badań eksploatacyjnych oraz warunki pracy wybudowanych w ostatnich latach gminnych oczyszczalni ścieków z wielofazowymi reaktorami osadu czynnego w układzie przepływowym. Oczyszczalnie te zapewniają wysoką efektywność usuwania zarówno związków organicznych jak i biogennych i przy prawidłowej eksploatacji spełniają zaostrzone wymagania dyrektywy dotyczącej oczyszczania ścieków komunalnych. Analiza pracy przedstawiona została na przykładzie trzech obiektów o porównywalnych rozwiązaniach technologicznych i różnym obciążeniu ładunkiem zanieczyszczeń. We wnioskach przedstawiono również doświadczenia eksploatacyjne z innych oczyszczalni z reaktorami wielofazowymi.

EN

The article presents operation parameters and conditions as well as treatment results of communal wastewater treatment plants. The plants have been built in recent years and they all have multi-phase activated sludge reactors (BNR reactors) working in a continuous flow mode. The plants provide a very good removal of both organic compounds and nutrients and meet the stringent requirements of the Directive on Urban Wastewater Treatment, if properly operated. The analysis covers three case studies of comparable technological systems and different pollution loads. In the conclusions the authors included also operational experiences from other treatment plants with multi-phase reactors.

2

Continuous mathematical models of airlift bioreactors: Families, affinity, diversity and modelling for single-substrate kinetics

Grzywacz R.

Chemical and Process Engineering

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2012

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Vol. 33, nr 2

291-309

EN

This paper presents a method of describing an airlift bioreactor, in which biodegradation of a carbonaceous substrate described by single-substrate kinetics takes place. Eight mathematical models based on the assumption of liquid plug flow and axial dispersion flow through the riser and the downcomer in the reactor were proposed. Additionally, the impact of degassing zone with assumed complete mixing on the obtained results was analyzed. Calculations were performed for two representative hydrodynamic regimes of reactor operation, i.e. with the presence of gas bubbles only within the riser and for complete gas circulation. The conclusions related to the apparatus design and process performance under sufficient aeration of the reaction mixture were drawn on the basis of the obtained results.

3

Prediction of gas holdup in the three-phase fluidized bed: air/Newtonian and non-Newtonian liquid systems

Sivakumar V., Senthilkumar K., Kannadasan T.

Polish Journal of Chemical Technology

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2010

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Vol. 12, nr 4

64-71

EN

The application of the three-phase fluidization technology in wastewater treatment and other biochemical processes has been regularly addressed in the past decades. For the design and development of the threephase fluidized bed reactors, knowledge of the hydrodynamic parameter such as gas holdup is essential and hence in this paper an attempt has been made to study the effect of fundamental and operating variables on gas holdup. On the basis of the experimental results, a unified correlation has been developed to predict gas holdup in the fluidized bed using the Newtonian and the non-Newtonian liquids. The experimental results showed good agreement with those predicted according to the developed correlation.

4

Catalytic semipermeable membrane - challenge and possibilities

Noworyta A.

Biocybernetics and Biomedical Engineering

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2008

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Vol. 28, no. 2

35-47

EN

Equations describing a multi-phase bioreactor with a catalytic membrane located on the boundary of phases, of which one is a substrate reservoir, are formulated. A model analysis of the process was carried out and the effect of main operating parameters of such a reactor, i.e. the catalytic layer thickness and the coefficients of diffusion mass transport in both phases, was determined. Two periods with different methods of supplying the catalytic layer can be distinguished in the process. There is also a characteristic thickness of the catalyst layer and when it is exceeded the process duration is no longer shortened although not always full substrate conversion from the supply stream has a place. It is recommended to apply thin layers, because then the catalyst activity is fully used. The analyse of the influence of mass transfer showed that substrate mass transfer in acceptor phase to the catalyst layer has a slight effect on the process rate when the intensification of its transfer in donor phase could have a significance influence on process rate.