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1

Hydrolysis of Lactose from Cheese Whey Using a Reactor with β-Galactosidase Enzyme Immobilised on a Commercial UF Membrane

100%

Regenhardt S. A., Mammarella E. J., Rubiolo A. C.

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vol. 34

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issue 3

375-385

EN

In this study, β-galactosidase enzyme from Kluyveromyces fragilis was immobilised on a commercial polyethersulfone membrane surface, 10 kDa cut-off. An integrated process, concerning the simultaneous hydrolysis-ultrafiltration of whey lactose was studied and working conditions have been fixed at 55°C and pH 6.9, the same conditions that are used for the industrial process of protein concentration. For the immobilisation, best results were obtained using 5% (v/v) of glutaraldehyde solution and 0.03 M galactose; the total activity recovery coefficient (TARC) was 44.2%. The amount of immobilised enzyme was 12.49 mg with a total activity of 86.3 LAU at 37°C, using 5% (w/v) lactose solution in phosphate buffer (100 mM pH 6.9). The stability of the immobilised enzyme was approximately 585 fold higher in comparison with the stability of free enzyme. Multipoint covalent immobilisation improves the stability of the enzyme, thereby enhancing the decision to use the membrane as a filtering element and support for the enzyme immobilisation.

2

A kinetic study on drinking water denitrification using a membrane bioreactor

88%

Petrovič A., Goršek A., Simonič M.

Open Chemistry

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2015

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vol. 13

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issue 1

EN

This study determines the basic parameters of Monod kinetics for microbial growth within a membrane bioreactor using the Zenon ZeeWeed 10 MBR system. The influent nitrate concentration was kept at 70 ± 2 mg L-1 NO3ˉ. During the experiments a constant concentration of activated sludge was maintained at approximately 0.76 g L-1 under anoxic conditions. Sucrose was added to the activated sludge as a carbon source. The Monod kinetic parameters were calculated by numerical interpolation, by considering experimental data. The maximum specific growth rate of the biomass was determined to be 0.31 h-1, half-saturation constant 5.4 mg L-1, and yield coefficient 0.35 mg biomass mg-1 COD. Afterwards, a dynamic simulation was performed within the calculated parameters. The dynamic concentration profiles for substrate and biomass were determined at different dilution rates within the range of 0.8 to 5 d-1.

3

Hydrolysis of Lactose from Cheese Whey Using a Reactor with β-Galactosidase Enzyme Immobilised on a Commercial UF Membrane

88%

Regenhardt S. A., Mammarella E. J., Rubiolo A. C.

Chemical and Process Engineering

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2013

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issue 3

4

Biological Regeneration of Liquid Sorbents after Industrial Purification of Outlet Gases

88%

Trusek-Holownia A., Noworyta A.

Chemical and Process Engineering

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2012

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vol. 33

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issue 4

667-678

EN

Biological regeneration of water and organic sorbents used in the absorption of hydrophilic and hydrophobic pollutants, respectively, was studied. In both cases biodegradation takes place in a membrane bioreactor. In the case of organic sorbents regeneration of the biodegradation process is integrated with the extraction of a given pollutant to water phase. In experiments carried out in this work, the proposed systems were tested using a strain of Pseudomonas fluorescens. For hydrophilic compounds experiments were performed using alcohols (1-butanol and 2-propanol) as model substrates. Applying the mathematical model of a membrane bioreactor elaborated previously, the values of pollutant concentration were determined and positively verified in the experiments. This system of water sorbent regeneration is fully satisfying. The process of biodegradation integrated with extraction was analysed on the basis of model compounds such as benzene and toluene. The study confirmed a possibility of organic sorbent (silicone oil) regeneration. However, due to a very high partition coefficient of benzene or toluene between the organic and aqueous phases, the process could be considered only for the case of their high concentrations in the gas directed to absorption.

5

Biological Regeneration of Liquid Sorbents after Industrial Purification of Outlet Gases

75%

Trusek-Holownia A., Noworyta A.

Chemical and Process Engineering

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2012

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issue 4

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4 Chemical and Process Engineering

1 Open Chemistry

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2 Mammarella E. J.

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2 Regenhardt S. A.

2 Rubiolo A. C.

2 Trusek-Holownia A.

1 Goršek A.

1 Petrovič A.

1 Simonič M.

Hydrolysis of Lactose from Cheese Whey Using a Reactor with β-Galactosidase Enzyme Immobilised on a Commercial UF Membrane

A kinetic study on drinking water denitrification using a membrane bioreactor

Hydrolysis of Lactose from Cheese Whey Using a Reactor with β-Galactosidase Enzyme Immobilised on a Commercial UF Membrane

Biological Regeneration of Liquid Sorbents after Industrial Purification of Outlet Gases

Biological Regeneration of Liquid Sorbents after Industrial Purification of Outlet Gases