Fluorescence-based monitoring of tracer and substrate distribution in an UASB reactor

Lou, S.J.; Tartakovsky, B.; Zeng, Yingzhi; Wu, Ping; Guiot, Serge R.

doi:10.1016/j.chemosphere.2006.03.045

Cited by 15 publications

(15 citation statements)

References 13 publications

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“…The experimental results reported by Lou et al 30 are used to validate this model. Their experiments were carried out with a 10.4-l UASB reactor.…”

Section: Mixing Characteristics Of a Uasb Reactormentioning

confidence: 97%

Hydrodynamics of upflow anaerobic sludge blanket reactors

Ren

et al. 2008

AIChE Journal

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in Wiley InterScience (www.interscience.wiley.com).The hydrodynamic characteristics of upflow anaerobic sludge blanket (UASB) reactors were investigated in this study. A UASB reactor was visualized as being set-up of a number of continuously stirred tank reactors (CSTRs) in series. An increasing-sized CSTRs (ISC) model was developed to describe the hydrodynamics of such a bioreactor. The gradually increasing tank size in the ISC model implies that the dispersion coefficient decreased along the axial of the UASB reactor and that its hydrodynamic behavior was basically dispersion-controlled. Experimental results from both laboratoryscale H 2 -producing and full-scale CH 4 -producing UASB reactors were used to validate this model. Simulation results demonstrate that the ISC model was better than the other models in describing the hydrodynamics of the UASB reactors. Moreover, a three-dimensional computational fluid dynamics (CFD) simulation was performed with an Eulerian-Eulerian three-phase-fluid approach to visualize the phase holdup and to explore the flow patterns in UASB reactors. The results from the CFD simulation were comparable with those of the ISC model predictions in terms of the flow patterns and dead zone fractions. The simulation results about the flow field further confirm the discontinuity in the mixing behaviors throughout a UASB reactor. American Institute of Chemical Engineers AIChE J, 55: 516-528, 2009

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“…The experimental results reported by Lou et al 30 are used to validate this model. Their experiments were carried out with a 10.4-l UASB reactor.…”

Section: Mixing Characteristics Of a Uasb Reactormentioning

confidence: 97%

Hydrodynamics of upflow anaerobic sludge blanket reactors

Ren

et al. 2008

AIChE Journal

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“…Model verification was carried out by comparing model outputs with the values of soluble COD and total VFAs measured on-line by the multi-wavelength fluorometric system (Lou et al, 2006). The on-line measurements used for the comparison were obtained between days 4 and 9 and included a transition between phases #1 and #2 due to the change in upflow velocity.…”

Section: Model Verification and Analysis Of Model Predictionsmentioning

confidence: 99%

Anaerobic digestion model No. 1-based distributed parameter model of an anaerobic reactor: II. Model validation

Tartakovsky

Zeng

et al. 2008

Bioresource Technology

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In this study, an ADM1-based distributed parameter model was validated using experimental results obtained in a laboratory-scale 10 L UASB reactor. Sensitivity analysis of the model parameters was used to select four parameters for estimation by a numerical procedure while other parameters were accepted from ADM1 benchmark simulations. The parameter estimation procedure used measurements of liquid phase components obtained at different sampling points in the reactor and under different operating conditions. Model verification used real time fluorescence-based measurements of chemical oxygen demand and volatile fatty acids at four sampling locations in the reactor. Overall, the distributed parameter model was able to describe the distribution of liquid phase components in the reactor and adequately simulated the effect of external recirculation on degradation efficiency. The model can be used in the design, analysis and optimization of UASB reactors.

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“…Una gran contradicción se observó en los resultados de un estudio realizado a escala piloto por de Carvalho (2008), cuando se usaron las ecuaciones propuestas por Levesnpiel en 1999 y se obtuvieron valores mayores para el modelo de gran dispersión y recipiente abierto (GDra) comparados con el de pequeña dispersión (PD). También se encontraron valores de dispersión diferentes con los mismos datos experimentales (reactor escala de laboratorio), los cuales fueron menores cuando se usó la ecuación de GDra (Lou et al 2006) y mayores al definir condiciones de borde adecuadas (Zeng et al 2005), del mismo modo que se observó en un estudio a escala real (Avella 2001, Peña et al 2006. Lo anterior permite afirmar que se pueden obtener resultados contradictorios si no se consideran las condiciones de borde reales.…”

Section: Resultados Y Discusiónunclassified

Evaluación Hidráulica De Un Reactor Anaerobio De Flujo Ascendente (Rafa) Usando Un Modelo De Dispersión Axial

Montiel

Villasmil

Alvarado

2016

Rev. Int. Contam. Ambie.

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Palabras clave: trazador, tiempo de retención hidráulico, flujo disperso, mezcla completa, zona muerta RESUMEN La hidráulica, junto con los procesos bioquímicos tiene una importancia esencial en la eficiencia de los sistemas de tratamiento biológico, tales como los reactores anaerobios de flujo ascendente (RAFA). En esta investigación se evaluó el desempeño hidráulico en un RAFA de 518 L utilizando un modelo de dispersión axial. El reactor fue inoculado con 105 L de lodo (20 % v/v) y se alimentó con agua residual municipal del colector C de la ciudad de Maracaibo, Venezuela. Los ensayos fueron realizados al agregar una solución de LiCl de forma puntual en el efluente. El Li + fue cuantificado como trazador. Las muestras fueron recolectadas en el efluente y en un punto intermedio del reactor a tiempos de retención hidráulica teóricos (t o ) de 10, 8, 5, 4 y 3 h con tres entradas alineadas en el fondo del reactor y a t o de 5 h incrementando las entradas de forma impar hasta llegar a 15. El número de dispersión obtenido en la zona de lecho y manto de lodo (punto intermedio) fue mayor que en el efluente, obteniendo valores de 1.1842 < d < 1.7550 y 0.2911 < d < 0.7285 respectivamente. El modelo de dispersión axial con inyección y recolección en flujo (IRF) e inyección en flujo y recolección en el fluido residente (IFRFR), presentó buenos ajustes a los datos experimentales de concentración del trazador. El reactor se comportó como mezcla completa en el lecho y manto de lodo y flujo disperso en el sedimentador.Key words: tracer, hydraulic retention time, dispersed flow, complete mix, dead zone ABSTRACT Hydraulics along with biogeochemical processes have a remarkable value in the efficiency of wastewater treatment systems as upflow anaerobic sludge reactors (UASB). In this study the hydraulic performance was evaluated on a UASB of 518L volume capacity using an axial dispersion model. The reactor was inoculated with 105 L of sludge (20 % v/v) and was fed with a local municipal wastewater flowing at the collector C of the city Maracaibo, Venezuela. Assays were carried out using a solution with LiCl (Li + measured as tracer) incorporated at the influent as instantaneous injection. Samples were collected at the effluent and at a midpoint of the reactor. Different theoretical hydraulic retention times (t o )

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Fluorescence-based monitoring of tracer and substrate distribution in an UASB reactor

Cited by 15 publications

References 13 publications

Hydrodynamics of upflow anaerobic sludge blanket reactors

Hydrodynamics of upflow anaerobic sludge blanket reactors

Anaerobic digestion model No. 1-based distributed parameter model of an anaerobic reactor: II. Model validation

Evaluación Hidráulica De Un Reactor Anaerobio De Flujo Ascendente (Rafa) Usando Un Modelo De Dispersión Axial

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