Modelling shock loadings and starvation in the biofiltration of toluene and xylene

Metris, A V; Gerrard, A. M.; Cumming, R. H.; Weigner, Pavel; Páca, Jan

doi:10.1002/jctb.422

Cited by 42 publications

(27 citation statements)

References 25 publications

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“…Response of conventional ͑unidirectional͒ flow biofilters to step increases in toluene concentration has been documented previously ͑Tang et al 1995;Marek et al 2000;Al-Rayes et al 2001;Irvine and Moe 2001;Métris et al 2001;Moe and Irvine 2001͒ and published data on FDS biofilter response to step increases in contaminant concentration appear to be limited to four studies by Kinney and Table 1. curves from this study are plotted together with data obtained from the other published studies in Fig. 4͑b͒.…”

Section: Resultsmentioning

confidence: 70%

Transient Response of Flow-Direction-Switching Vapor-Phase Biofilters

2005

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Transient loading of vapor-phase biofilters may result in exceedence of the local reaction or mass transfer capacity of the inlet region. In such cases, higher concentrations of contaminants are carried deeper into the bed where there is less active biomass and, in some cases, breakthrough of contaminants may occur. Previous studies have demonstrated that periodic reversal of the flow direction results in improved transient-loading response. However, quantitative information on the extent of the benefit is lacking.Step function increases in toluene concentration were applied to unidirectional-flow and flow-direction-switching laboratory reactors operated in parallel. Contaminant concentration was monitored at several points along the packed beds. Relative to unidirectional mode of operation, periodic flow reversal produced a more uniform distribution of microbial reaction capacity along the length of the packed bed. Directional switching at a 12-h interval did not result in a loss of activity or removal capacity. Mass-removal rates under transient-loading conditions were similar in the first-half of both biofilters but, in the second-half of the units, significant removals were observed only in the flow-direction-switching biofilter. As a result, maximum mass-removal rates under transient-loading conditions were approximately twice as great for the flow-direction-switching biofilter relative to the conventional unidirectional-flow biofilter receiving similar mass loading.

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Section: Resultsmentioning

confidence: 70%

Transient Response of Flow-Direction-Switching Vapor-Phase Biofilters

2005

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“…This knowledge regarding inorganic nutrient requirements will help lead to more effective formulation of media to meet specific operating objectives without wasteful oversupply. Furthermore, this information could be used to help develop a preemptive nutrient supplementation strategy of the types routinely practiced in biofilter applications [27][28][29].…”

Section: Discussionmentioning

confidence: 99%

Benzene vapor treatment using a two-phase partitioning bioscrubber: an improved steady-state protocol to enhance long-term operation

Nielsen

Sask

McLellan

2006

Bioprocess Biosyst Eng

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The performance and stability of a two-phase partitioning bioscrubber (TPPB) containing 33% (vol.) n-hexadecane as an immiscible phase was investigated during 30 days of continuous gaseous benzene treatment. Elimination capacities of 141 +/- 12 g/m(3) h were achieved by Achromobacter xylosoxidans Y234 while maintaining >99% removal throughout. A new steady-state operating strategy that limits excessive biomass production by directing substrate consumption to maintenance energy has eliminated the requirement for frequent exchange of liquid contents. Simplifying the operating protocols in this manner has dramatically reduced material costs and rendered the TPPB operational requirements as more comparable (in terms of frequency of required operator inputs) with other vapor-phase bioreactors. The practicality of the proposed simplification to the operating protocol was confirmed by demonstrating that intermediate metabolites were not accumulating in the TPPB, inorganic nutrient requirements were readily predictable, and that high culture viability could be sustained for prolonged cell retention times (30 days).

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“…Correspondingly, off-gas characteristics from manufacturing and commercial operations will typically vary with time due to changes in processes, shut downs, shift changes, and spills. The performance of biofilters subject to transient loadings have been studied by a number of researchers ͑Al- Rayes et al 2001;Campbell and Connor 1997;Damborsky et al 1999;Deshusses 1995;Deshusses et al 1995Deshusses et al , 1996Deshusses et al , 2001DirkFaitakis and Allen 1998;Ergas et al 1995a, b;Hodge and Divinney 1995;Irvine and Moe 2001;Kinney 1996;Kirchner et al 1994; Leson and Winer 1991;Marek et al 2000;Martin and Loehr 1996;Métris et al 2001;Moe and Irvine 2001;Mysliwiec et al 2001;Park and Kinney 2001;Parks and Loehr 1994;Schroeder et al 2000;Schroeder 2002;Seed and Corsi 1994;Shi et al 1995;Kinney 2000, 2001;South Coast Air Quality Management District 1994;Tang et al 1995;Tang and Hwang 1997;Tonga and Frisch 1993;Weber and Hartmans 1995;Woertz et al 2001;Wright 2004;Wright et al 1997. However, more information is needed because the relationship between transient loadings and biofilter response remains poorly understood ͑Deshusses 1995; Deshusses et al 1996;Irvine and Moe 2001;…”

Section: Introductionmentioning

confidence: 99%

Regular Transient Loading Response in a Vapor-Phase Flow-Direction-Switching Biofilter

2005

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Abstract:The principal objective of this study was determination of the response of a laboratory-scale vapor-phase flow-directionswitching biofilter to loading changes associated with normal operations such as lunch breaks, overnight shutdowns, and single-shift operation of commercial and industrial facilities. Three regular transient loading cases were considered: ͑a͒ variable flow-reversal interval lenghts, ͑b͒ variable feed-on/off interval lengths, and ͑c͒ variable inlet concentration during a repeating feed-on/off cycle. Toluene was used as the model contaminant compound. The most significant findings of the study were: ͑1͒ Relative to unidirectional mode of operation, periodic flow reversal produced a more uniform distribution of reaction capacity along the length of the packed bed; ͑2͒ a 12 h flow reversal interval was sufficiently short to maintain the toluene-degrading microbial community in a near-fully active state throughout the unit whereas a 2 day flow reversal interval resulted in diminished removal rates in the first half of the bed and ͑3͒ Increasing off-period length resulted in greater penetration of contaminant into the bed and more uniform removal rates along the length of the bed. Information developed in this study should provide a more complete basis for establishing operating protocols and monitoring regulations for vapor-phase biofiltration systems.

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Modelling shock loadings and starvation in the biofiltration of toluene and xylene

Cited by 42 publications

References 25 publications

Transient Response of Flow-Direction-Switching Vapor-Phase Biofilters

Transient Response of Flow-Direction-Switching Vapor-Phase Biofilters

Benzene vapor treatment using a two-phase partitioning bioscrubber: an improved steady-state protocol to enhance long-term operation

Regular Transient Loading Response in a Vapor-Phase Flow-Direction-Switching Biofilter

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