Use of sealed end hollow fibers for bubbleless membrane aeration: experimental studies

Ahmed, Tariq; Semmens, Michael J.

doi:10.1016/0376-7388(92)80162-d

Cited by 153 publications

(61 citation statements)

References 7 publications

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“…The silicone membrane and tubing were operated in a dead-end mode. This mode of operation allowed for an elevated gas pressure in the system due to gas build up, which increased the concentration gradient and hence the mass transfer of CO (Ahmed and Semmens, 1992). The CO K L a for silicone membrane and tubing were estimated to be 0.63 ± 0.1 and 0.76 ± 0.2 h À1 , respectively.…”

Section: Estimation Of K L Amentioning

confidence: 95%

“…Dense polymer membranes, such as silicone membranes, offer an advantage over micro-porous membranes as they can be operated under high pressure conditions, which increase the concentration gradient and hence, the mass transfer rate (Côté et al, 1989). Silicone membranes have been reported to be ideal for membrane based bubble-less aeration without vigorous mixing where a conventional system is unable to meet the O 2 requirements of a higher rate system (Ahmed and Semmens, 1992;Côté et al, 1989). They also find wide applicability in modified atmosphere storage for fruits and vegetables because of efficient regulation of the gas levels in the storage chamber due to their selective gas permeation properties (Gariépy et al, 1994).…”

Section: Introductionmentioning

confidence: 99%

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Use of silicone membranes to enhance gas transfer during microbial fuel cell operation on carbon monoxide

Hussain

Tartakovsky

Guiot

et al. 2011

Bioresource Technology

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Use of silicone membranes to enhance gas transfer during microbial fuel cell operation on carbon monoxide Hussain, A.; Tartakovsky, B.; Guiot, S. R.; Raghavan, V.Use of silicone membranes to enhance gas transfer during microbial fuel cell operation on carbon monoxide Electricity generation in a microbial fuel cell (MFC) using carbon monoxide (CO) or synthesis gas (syngas) as a carbon source has been demonstrated recently. A major challenge associated with CO or syngas utilization is the mass transfer limitation of these sparingly soluble gases in the aqueous phase. This study evaluated the applicability of a dense polymer silicone membrane and thin wall silicone tubing for CO mass transfer in MFCs. Replacing the sparger used in our previous study with the membrane systems for CO delivery resulted in improved MFC performance and CO transformation efficiency. A power output and CO transformation efficiency of up to 18 mW L À1 R (normalized to anode compartment volume) and 98%, respectively, was obtained. The use of membrane systems offers the advantage of improved mass transfer and reduced reactor volume, thus increasing the volumetric power output of MFCs operating on a gaseous substrate such as CO.

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Section: Estimation Of K L Amentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Use of silicone membranes to enhance gas transfer during microbial fuel cell operation on carbon monoxide

Hussain

Tartakovsky

Guiot

et al. 2011

Bioresource Technology

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“…One technological alternative to conventional coarse and fine bubble diffusers is the use of microporous membranes that contain small (Ͻ0.1 m) hydrophobic pores for bubbleless oxygen transfer to the wastewater (1). Biofilms actively grow on these membranes, such that membrane-aerated biofilm (MAB) reactors can treat wastewater at rates comparable to conventional suspended-growth processes (6,33,37).…”

mentioning

confidence: 99%

Stratification of Activity and Bacterial Community Structure in Biofilms Grown on Membranes Transferring Oxygen

Cole

Semmens

LaPara

2004

Appl Environ Microbiol

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124

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Previous studies have shown that membrane-aerated biofilm (MAB) reactors can simultaneously remove carbonaceous and nitrogenous pollutants from wastewater in a single reactor. Oxygen is provided to MABs through gas-permeable membranes such that the region nearest the membrane is rich in oxygen but low in organic carbon, whereas the outer region of the biofilm is void of oxygen but rich in organic carbon. In this study, MABs were grown under similar conditions but at two different fluid velocities (2 and 14 cm s ؊1 ) across the biofilm. MABs were analyzed for changes in biomass density, respiratory activity, and bacterial community structure as functions of biofilm depth. Biomass density was generally highest near the membrane and declined with distance from the membrane. Respiratory activity exhibited a hump-shaped profile, with the highest activity occurring in the middle of the biofilm. Community analysis by PCR cloning and PCR-denaturing gradient gel electrophoresis of 16S rRNA genes demonstrated substantial stratification of the community structure across the biofilm. Population profiles were also generated by competitive quantitative PCR of gene fragments specific for ammonia-oxidizing bacteria (AOB) (amoA) and denitrifying bacteria (nirK and nirS). At a flow velocity of 14 cm s ؊1 , AOB were found only near the membrane, whereas denitrifying bacteria proliferated in the anoxic outer regions of the biofilm. In contrast, at a flow velocity of 2 cm s ؊1 , AOB were either not detected or detected at a concentration near the detection limit. This study suggests that, under the appropriate conditions, both AOB and denitrifying bacteria can coexist within an MAB.The aeration of bioreactors is one of the most significant operating costs incurred during the treatment of municipal and industrial wastewaters. One technological alternative to conventional coarse and fine bubble diffusers is the use of microporous membranes that contain small (Ͻ0.1 m) hydrophobic pores for bubbleless oxygen transfer to the wastewater (1). Biofilms actively grow on these membranes, such that membrane-aerated biofilm (MAB) reactors can treat wastewater at rates comparable to conventional suspended-growth processes (6,33,37). MAB reactors have lower operating costs, because oxygen transfer efficiency approaches 100% (5, 26) and because expensive air compression is no longer required (9). In addition, MAB reactors generate fewer odors, because volatile pollutants are not released into the atmosphere (5, 6).MABs are unique compared to biofilms grown on inert substrata. Nutrient concentrations in MABs are highest at the biofilm-liquid boundary and decrease with depth into the biofilm; in contrast, oxygen concentrations are highest at the membrane and decrease toward the outside of the biofilm (Fig. 1). In thick MABs, oxygen partially penetrates the biofilm, generating an anoxic zone at the biofilm-liquid boundary (6). In such biofilms, the region of greatest microbial activity is variable and depends on the relative availability of oxygen a...

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“…Using a membrane gas transfer device can resolve these concerns while meeting his suggestions (Semmens, 1991). Several studies (Ahmed and Semmens, 1992;Semmens andGantzer, 1993:-Pankhania et al, 1994) Bubble-less membrane gas diffusion was recently employed in the water/wastewater treatment process for bubble-free oxygenation in which pure oxygen was delivered without bubble formation (Cote, 1986). Bubble-less oxygenation can be accomplished by hollow fiber membranes with the oxygen phase on the lumen side and the wastewater on the shell side of the fibers.…”

Section: Reverse Osmosismentioning

confidence: 99%

Hydrogenotrophic Denitrification of Groundwater in a Membrane Bioreactor Assisted by Membrane Gas Diffusion

Mo¹,

Oleszkiewicz²,

Çiçek³

et al. 2004

proc water environ fed

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Use of sealed end hollow fibers for bubbleless membrane aeration: experimental studies

Cited by 153 publications

References 7 publications

Use of silicone membranes to enhance gas transfer during microbial fuel cell operation on carbon monoxide

Use of silicone membranes to enhance gas transfer during microbial fuel cell operation on carbon monoxide

Stratification of Activity and Bacterial Community Structure in Biofilms Grown on Membranes Transferring Oxygen

Hydrogenotrophic Denitrification of Groundwater in a Membrane Bioreactor Assisted by Membrane Gas Diffusion

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