Biocatalytic membrane reactor

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Effect of operational parameters on the performance of a magnetic responsive biocatalytic membrane reactor

Effect of operational parameters on the performance of a magnetic responsive biocatalytic membrane reactor

Identification of an optimal operating condition laid the platform for continuous operation of the BMR SP over 200 h, without visible transmembrane pressure drift while maintaining constant flux. Product assay in the permeate gave constant value in the entire duration, i.e., no enzymatic activity decay owing to Abbreviations: Enz SP ,, enzyme functionalized superparamagnetic nanoparticles; M SP ,, superparamagnetic membrane; TMP,, transmembrane pressure; BMR SP ,, superparamagnetic biocatalytic membrane reactor; NP SP ,, superparamagnetic nanoparticles; DMF,, dimethylformamide; PVDF,, polyvinylidene fluoride; GalA,, galacturonic acid; APTMS,, 3-aminopropyl) trimethoxysilane; PEG,, polyethylene glycol; BCA,, bicinchoninic Acid; Pe,, Peclet number; J opt ,, optimum flux (L/m 2 h); SEM,, scanning electron microscopy.
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Pectinases immobilization on magnetic nanoparticles and their anti-fouling performance in a biocatalytic membrane reactor

Pectinases immobilization on magnetic nanoparticles and their anti-fouling performance in a biocatalytic membrane reactor

Enzyme immobilization on commercial superparamagnetic nanoparticles (NP SP ) was performed using covalent bonding. The biofunctionalized NP SP was then immobilized on the surface of the membrane using an external magnetic field to form a magneto-responsive biocatalytic membrane reactor (BMR SP ). The magnetically formed smart nanolayer can be easily re-dispersed and recovered from the membrane when the enzyme is deactivated or whenever cleaning is required due to substrate over-accumulation. The system was used to hydrolyze pectin contained in di fferent streams. Results are supported with complementary data from hydrodynamic, kinetic and morphological characterization in a flow-through reactive filtration. Wavelength-dispersive X-ray spectroscopy (WDS) elemental mapping revealed that the NP SP are uniformly dispersed on the surface of the membrane forming a thin biocatalytic layer. Both results of hydrodynamic studies and SEM micrographs of the membrane with the enzyme layer under various operating conditions, show that the immobilized enzyme e ffectively reduced membrane–foulant interaction. Comparison of filtration data using this commercial NP SP reveals good agreement with our previously used home-made NP SP . This implies that the scaling-up and commercialization of the developed BMR SP can be straightforward.
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Pectinases immobilization on magnetic nanoparticles and their anti-fouling performance in a biocatalytic membrane reactor

Pectinases immobilization on magnetic nanoparticles and their anti-fouling performance in a biocatalytic membrane reactor

On the other hand, biocatalyst immobilized on nano-sized particles e.g., titania, carbon nanotubes with maximum surface area and activity have been applied in biocatalysis. 6 –9 The key drawback of such stirred tank reactors (STR) with inert carrier particles is recovery of the nano-catalyst, enzyme- product inhibition and regeneration or disposal of spent materials. 10 An alternative is to coat the biocatalyst on poly- meric membranes in a biocatalytic membrane reactor (BMR). 11 This creates reactive surfaces for enhanced separa- tions while eliminating the complexity of biocatalyst recovery. However, this method mainly suffers from irreversible attachment of the biocatalyst on the membrane and loss in intrinsic permselectivity of the membrane. 12 In particular, enzyme deactivation during membrane cleaning is among the current bottle-necks that limit the speed-up of BMR at industrial level.
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Effect of operational parameters on the performance of a magnetic responsive biocatalytic membrane reactor

Effect of operational parameters on the performance of a magnetic responsive biocatalytic membrane reactor

Stimuli-responsive membrane a b s t r a c t In this work, the performance of an innovative magnetic responsive biocatalytic membrane reactor (BMR SP ) has been investigated under various operational parameters. In particular, feed concentrations, flow rates across the bed, temperature and amount of biocatalytic bead were varied to probe the flow- dependent transport and kinetic properties of the reaction and the subsequent hydrolytic performance of the BMR SP . The rate of fouling for the BMR SP was always lower than a corresponding control system. For a given enzymatic concentration, a constant foulant hydrolyzing capacity is identified. At 3 g/m 2 pectinase containing bionanocomposites, the BMR SP hydrolytic efficiency was 1.5 g/m 2 h. This efficiency was further increased by increasing the amount of bionanocomposites per membrane area. This further allowed the BMR SP to hydrolyze higher loads of foulants while keeping a low if not zero increase in TMP over time at constant flux.
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Evaluation of membrane characteristics and thermal polarization in membrane distillation

Evaluation of membrane characteristics and thermal polarization in membrane distillation

The scale formation at the membrane surface has been observed in the studies addressing the MD applied to solutions containing salts. Gryta [82] has investigated the membrane distillation performance in treating the spent solution from heparin production. The rapid flux declined was reported due to the fouling and scaling. The presence of salts deposits on distillate side confirms the occurrence of wetting as well. The removal of foulants by boiling the feed followed by the separation of the deposits was found to be an affective pretreatment to reduce the fouling during the membrane distillation process. The problem of scale formation at the distribution channel of the membrane modules and at the membrane surface was observed in a study conducted by Kullab and Martin [83] for production of water for cogeneration power plants. The permeate quality and the operation stability was dependent upon the nature of the feedstock. Ca and Mg were identified as the main scale forming salts. In another study, Gryta [84] has analyzed the performance of MD against several different types of feed solutions including brine, bilge water and water containing protein. The strength and nature of fouling was dependent upon the feed and operating conditions used. The formation of Ca and protein based deposits on the membrane surface was detected. The scale formation in MD was pointed out as one of the major responsible factors for wetting, flux reduction and damage to the membrane structure. The formation of porous deposits decreases the flux by lowering the heat transferred to the membrane surface while the non-porous deposits increase the resistance to the mass transfer. The scaling occurred at membrane surface and in distribution channels observed in various studies has been shown in Figure 2.8.
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The centrifugal partition reactor, a novel intensified continuous reactor for liquid–liquid enzymatic reactions

The centrifugal partition reactor, a novel intensified continuous reactor for liquid–liquid enzymatic reactions

For a typical configuration, the productivity of the CPR was eval- uated to be more favorable than the conventional batch reactor. In addition, the CPR has other benefits: a liquid–liquid separation for catalyst recycling is not necessary because this step is integrated in the system and also, compared to batch reactor, continuous operation eliminates a lot of manipulations in the process (vessel discharge, introduction of reactants. . .). This study has illustrated the advantage of the CPC equipment as an intensified reactor for two phase enzymatic reactions and the promising results obtained in this study are a good incentive to promote the CPR as a compet- itive innovative technology for industrial enzymology. Although centrifuge devices are usually known as high energy consuming devices [28] , in the CPC system, conversely to centrifuge contac- tors, there is no relative movement of the walls. So, maintaining the rotation only requires providing energy to overcome friction for moving metallic pieces, which can be very low for mechanically well designed systems. The main consumption is then the power for pumping which depends on the pressure drop of the mobile phase flow. Rough preliminary calculations (not presented here) enable us to estimate that energy consumption of the CPR is of the same order of magnitude than for a stirred tank reactor of the same vol- ume. Indeed, the CPR equipment does not aim at competing with the batch stirred tank reactor on the point of view of energy con- sumption. A possible advantage of the stirred tank reactor on this criterion would be largely balanced by the interest of operating a continuous steady production, which is not easily possible in a stirred biphasic batch reactor.
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Core design and reactor physics of a breed and burn gas-cooled fast reactor

Core design and reactor physics of a breed and burn gas-cooled fast reactor

Despite the large reactivity worth associated with control rod ejection at the EOEC (which could be corrected with a control rod design change) the advanced core has consiste[r]

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The centrifugal partition reactor, a novel intensified continuous reactor for liquid–liquid enzymatic reactions

The centrifugal partition reactor, a novel intensified continuous reactor for liquid–liquid enzymatic reactions

For a typical configuration, the productivity of the CPR was eval- uated to be more favorable than the conventional batch reactor. In addition, the CPR has other benefits: a liquid–liquid separation for catalyst recycling is not necessary because this step is integrated in the system and also, compared to batch reactor, continuous operation eliminates a lot of manipulations in the process (vessel discharge, introduction of reactants. . .). This study has illustrated the advantage of the CPC equipment as an intensified reactor for two phase enzymatic reactions and the promising results obtained in this study are a good incentive to promote the CPR as a compet- itive innovative technology for industrial enzymology. Although centrifuge devices are usually known as high energy consuming devices [28] , in the CPC system, conversely to centrifuge contac- tors, there is no relative movement of the walls. So, maintaining the rotation only requires providing energy to overcome friction for moving metallic pieces, which can be very low for mechanically well designed systems. The main consumption is then the power for pumping which depends on the pressure drop of the mobile phase flow. Rough preliminary calculations (not presented here) enable us to estimate that energy consumption of the CPR is of the same order of magnitude than for a stirred tank reactor of the same vol- ume. Indeed, the CPR equipment does not aim at competing with the batch stirred tank reactor on the point of view of energy con- sumption. A possible advantage of the stirred tank reactor on this criterion would be largely balanced by the interest of operating a continuous steady production, which is not easily possible in a stirred biphasic batch reactor.
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Cell Membrane Electropermeabilization

Cell Membrane Electropermeabilization

force contributes signi ficantly to the increase in “electroleaks” across the plasma membrane, that is, in P s . 53 The last term is re flecting the resealing. Fig. 1 Change in orientation and induction of permeabilization of rod shaped bacteria. (A) Before the pulse delivery, the orientation of each bacte- rium in the population is random. (B) During the pulse train, an orientation parallel to the field is induced with the same kinetic. Permeabilization is present only under the high field condition and affects all the surface of the bacteria (low grey). (C) After the pulse train, all bacteria are oriented parallel to the field. Permeabilization is present at a high level (dark grey) all over the surface under the high field condition, while only a cap is affected under the low field condition (low grey).
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Controllable Display of Sequential Enzymes on Yeast Surface with Enhanced Biocatalytic Activity toward Efficient Enzymatic Biofuel Cells

Controllable Display of Sequential Enzymes on Yeast Surface with Enhanced Biocatalytic Activity toward Efficient Enzymatic Biofuel Cells

Controllably Co-Displaying Sequential Enzyme GA and GOx via Bifunctional System and Their Biocatalytic Efficiencies. The sequential enzyme system in this work was further constructed by incubating yeast cells displaying the bifunctional scaffoldin with a saturating level of two enzymes (Figure 2). It is worthy of note that the overall reaction rate was sensitive to the assembling sequence of GA-DocC and GOx-DocT onto the chimeric scaffold (Table 1). Specifically, when the fusion protein GA-DocC was first bound onto the scaffoldin CohC-CohT, the complex showed considerable overall reaction rate and reached 13.16±0.81 nmol H 2 O 2 min -1
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Design of a percolation reactor

Design of a percolation reactor

flow analysis using porous media theory is described, the percolation reactor properties, the flow regime, the pressure drop, and the shear stress are defined.. Chapter 5 p[r]

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Compact ignition test reactor (CITR)

Compact ignition test reactor (CITR)

The CITR will be used to study thermal stability control. Thermal stability control is required in an ignited plasma to permit steady operation at whatever temperature[r]

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Roofing membrane design

Roofing membrane design

Architects, in the past, have not always been concerned with the design of roofing membranes, and it has been usual to accept the recommendations of manufacturers of roofing felts or of roofers. A successful roof was not always assured by this procedure, although when guarantee bonds were issued a reasonable standard existed for membrane specification and construction. Other considerations in the design of a roofing system were often ignored, however.

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Modulating biocatalytic activity towards sterically bulky substrates in CO2-expanded bio-based liquids by tuning physicochemical properties

Modulating biocatalytic activity towards sterically bulky substrates in CO2-expanded bio-based liquids by tuning physicochemical properties

ABSTRACT: The study of CO 2 -expanded liquids using a green component such as a biobased solvent has been recently raised as a new concept for an alternative solvent and yet been largely unexplored in the literature for neither fundamental nor application studies. On the other hand, structural bulkiness of substrates remains one of the main limitations to promote enzymes as an efficient versatile catalytic tool for organic synthesis, especially biocatalysis in nonconventional solvents. Herein, we report a detailed investigation of CO 2 -expanded biobased liquids as reaction media for improved biocatalysis of sterically hindered compounds. We found that CO 2 acts as a crucial trigger for various lipases to catalyze transesterification of challenging bulky alcohols in CO 2 -expanded 2-methyltetrahydrofuran (MeTHF). Furthermore, this study determines the physicochemical and transport properties of CO 2 -expanded MeTHF for the first time, which were then utilized for modulating biocatalytic activity. It was found that lipase activity increased with the accordingly decrease of the dipolarity of CO 2 -expanded MeTHF, which is tunable by altering the concentration of CO 2 in the solvent system.
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Protected-membrane roofs

Protected-membrane roofs

Some plastic insulations otherwise suitable for protected membrane roofs are subject to deterioration if exposed to radiation. Paint coatings might be considered adequate protection against ultra-violet but they will not guard against damage from hail or traffic, and uplift and flotation resistance must be provided by the adhesive bond between the insulation and the membrane and between the membrane and the deck. The effectiveness of the adhesive will depend on the smoothness, cleanness and dryness of the deck and membrane and on the care of application. It may be wise to consider ballasting by gravel or concrete slabs for all protected membrane roofs. Corners and edges of buildings, which are particularly vulnerable to wind uplift, should be ballasted even where the remainder of a paint protected insulation surface is exposed.
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Modulating biocatalytic activity towards sterically bulky substrates in CO2-expanded bio-based liquids by tuning physicochemical properties

Modulating biocatalytic activity towards sterically bulky substrates in CO2-expanded bio-based liquids by tuning physicochemical properties

causing the lipase to be more tolerant to accept more bulky substrates, and (3) enhanced transport and physicochemical properties of the expanded MeTHF compared to neat solvent.. When st[r]

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Polycopie de cours Membrane et Bioénergétique

Polycopie de cours Membrane et Bioénergétique

 La mobilité des molécules de lipides La mobilité des molécules de lipides à l'intérieur de la membrane plasmique est hyper-rapide à l'intérieur d'une même couche (107 fois/seconde ).Ceci permet la diffusion latérale rapide des molécules insérées dans la membrane à l'intérieur de la même couche ( ex: une molécule de protéine peut parcourir 2 μ / seconde). De plus il existe une mobilité des molécules lipidiques autour de leur axe et des mouvements de flexion des acides gras. La bicouche se comporte comme un liquide bidimensionnel (modèle de la mosaïque fluide). Par contre la mobilité des lipides est hyperlente d'une couche à l'autre (1 bascule toutes les 2 semaines: flipflop) : il y a donc quasi absence de flip-flop des phospholipides . Ceci permet de conserver une asymétrie de composition phospholipidique dans les deux feuillets de la bicouche
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Assesment of potential swelling of Pressurized Water Reactor internals The GONDOLE experiment in Osiris reactor

Assesment of potential swelling of Pressurized Water Reactor internals The GONDOLE experiment in Osiris reactor

• To improve density measurements uncertainty (new measurements of the ‘before GONDOLE irradiation state’ - virgin specimens and some pre- irradiated archive specimens). • To perform T[r]

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Liquid membrane extraction lipopeptides

Liquid membrane extraction lipopeptides

[5] H.L. Chen, R.S. Juang, Biochem. Eng. J., 2008, 38, 39. [6] K. Schügerl, J. Hubbuch, Current Opinion in Microbiology, 2005, 8, 294. [7] T. Liu, L. Montastruc, F. Gancel, L. Zhao, I. Nikov, Biochem. Eng. J., 2007, 35, 333. [8] L. Montastruc, T. Liu, F. Gancel, L. Zhao, I. Nikov, Biochem. Eng. J., 2008, 38, 349. [9] L. Boyadzhiev, Z. Lazarova, Liquid membranes (liquid pertraction), in: Membrane

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Current-Induced Membrane Discharge

Current-Induced Membrane Discharge

In conclusion, we have theoretically demonstrated that OLC through aqueous ion-exchange membranes can result from CIMD, or loss of ion selectivity due to (de-) protonation coupled to ion transport and water self- ionization. The appearance of OLC carried partially by salt co-ions and water ions reduces separation efficiency in electrodialysis, but the associated large pH gradients and membrane discharge could be exploited for current- assisted ion exchange or pH control. In addition to the effect of the water ions, the loss of ion selectivity due to CIMD leads to a further suppression of the nonequilibrium space charge that is much larger than in any of the models M 1 , M 2 , and M 4 , see Fig. 4(a) . The nonequilibrium space charge is responsible for EOI and thus CIMD should be considered in both models and experiments on OLC with
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