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Abstract

The study was to determine the effect of water activity (0.850; 0.900; 0.950; 0.995; and 0.999 aw) on the growth of T. lanuginosus on solid media containing different cellulose substrates (crystalline cellulose, carboxymethyl cellulose - CMC, fi lter paper, and sawdust) and xylan. The growth of isolates from coffee beans and garden composts were compared. All isolates did not grow on media with aw < 0.950. On media with aw > 0.950, the hydrolysis zones were only observed on xylan and CMC. The highest daily growth and hydrolysis zone rates were mostly obtained at 0.995 aw and the lowest values were observed at 0.950 aw. The coffee beans isolates at 0.950 aw had the CMC hydrolysis coeffi cient 1.7-times higher than that for xylan. The fungal growth (FG) coeffi cient data indicate that the coffee beans isolates were able to utilize CMC and crystalline cellulose for growth and the highest growth rate was obtained at 0.999 aw. Subsequently, the compost isolates were able to grow on all substrates but the highest growth rate was obtained on CMC at 0.950 and 0.999 aw. Thus, coffee beans and composts provide T. lanuginosus isolates with various growth and hydrolytic zone rates in the range of 0.950−0.999 aw.
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Authors and Affiliations

Agata Markowska-Szczupak
Krzysztof Ulfig
Katarzyna Janda
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Abstract

Environmental contamination is an urgent topic to be solved for sustainable society. Among various pollutants, microorganisms are believed to be the most dangerous and difficult to be completely inactivated. In this research, a new hybrid photoreactor assisted with rotating magnetic field (RMF) has been proposed for the efficient removal of two types of bacteria, i.e., gram-negative Escherichia coli and gram-positive Staphylococcus epidermidis. Three selfsynthesized photocatalysts were used, based on commercial titanium(IV) oxide - P25, homogenized and then modified with copper by photodeposition, as follows: 0.5Cu@HomoP25, 2.0Cu@HomoP25 and 5.0Cu@HomoP25 containg 0.5, 2.0 and 5.0 wt% of deposited copper, respectively. The response surface methodology (RSM) was employed to design the experiments and to deteremine the optimal conditions. The effects of various parameters such as copper concentration [% w/w], time [h] and frequency of RMF [Hz] were studied. Results: Analysis of variance (ANOVA), revealed a good agreement between experimental data and proposed quadratic polynomial model ((R2=0.86 for E. coli and R2=0.69 for S. epidermidis). Experimental results showed that with increasing copper concentration, time and decreasing of frequency of RMF removal efficiency was increased. Accordingly, the water disinfection efficiency of 100% in terms of the independent variables was optimized, including cooper concentration c =5 % and 2.5% w/w, time t = 3 h and 1.3 h and frequency of rotating magnetic field f = 50 Hz and 26.6 for E.coli and S. epidermidis, respectively. This study showed that response surface methodology is a useful tool for optimizing the operating parameters for photocatalytic disinfection process.
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Authors and Affiliations

Oliwia Paszkiewicz
1
ORCID: ORCID
Kunlei Wang
2
ORCID: ORCID
Marian Kordas
1
ORCID: ORCID
Rafał Rakoczy
1
ORCID: ORCID
Ewa Kowalska
2 3
ORCID: ORCID
Agata Markowska-Szczupak
1
ORCID: ORCID

  1. West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technologyand Engineering, Department of Chemical and Process Engineering, Piastow 42, 71-065Szczecin, Poland
  2. Hokkaido University, Institute for Catalysis (ICAT), N21, W9, 001-0021 Sapporo, Japan
  3. Jagiellonian University, Faculty of Chemistry, Gronostajowa 2, 30-387 Krakow, Poland
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Abstract

We demonstrate in this study that a rotating magnetic field (RMF) and spinning magnetic particles using this kind of magnetic field give rise to a motion mechanism capable of triggering mixing effect in liquids. In this experimental work two mixing mechanisms were used, magnetohydrodynamics due to the Lorentz force and mixing due to magnetic particles under the action of RMF, acted upon by the Kelvin force. To evidence these mechanisms,we report mixing time measured during the neutralization process (weak acid-strong base) under the action of RMF with and without magnetic particles. The efficiency of the mixing process was enhanced by a maximum of 6.5% and 12.8% owing to the application of RMF and the synergistic effect of magnetic field and magnetic particles, respectively.
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Bibliography

Baldyga J., Bourne J.R., 1988. Calculation of micromixing in inhomogenous stirred tank reactors. Chem. Eng. Res. Des., 66(1), 33–38.

Baldyga J., Bourne J.R., 1992. Interactions between mixing on various scales in stirred tank reactors. Chem. Eng. Sci., 47, 1839–1848. DOI: 10.1016/0009-2509(92)80302-S.

Bałdyga J., Pohorecki R., 2013. Editorial. 14th European Conference on Mixing. Chem. Eng. Res. Des., 91(11), 2071–2072). DOI: 10.1016/j.cherd.2013.10.021.

Bao S.R., Zhang R.P., Rong Y., Zhi X.Q., Qiu L.M., 2019. Interferometric study of the heat and mass transfer during the mixing and evaporation of liquid oxygen and nitrogen under non-uniform magnetic field. Int. J. Heat Mass Transfer, 136, 10–19. DOI: 10.1016/j.ijheatmasstransfer.2019.02.044.

Boroun S., Larachi F., 2016. Role of magnetic nanoparticles in mixing, transport phenomena and reaction engineering – challenges and opportunities. Curr. Opin. Chem. Eng., 13, 91–99. DOI: 10.1016/j.coche.2016.08.011.

Boulware J.C., Ban H., Jensen, S., Wassom S., 2010. Influence of geometry on liquid oxygen magnetohydrodynamics. Exp. Therm Fluid Sci., 34, 1182–1193. DOI: 10.1016/j.expthermflusci.2010.04.007.

Chen X., Zhang L., 2019. A review on micromicers acuated with magnetic nanomaterials. Microchim Acta, 184, 3639–3649. DOI: 10.1007/s00604-017-2462-2.

Davidson P.A., 1999. Magnetohydrodynamics in materials processing. Annu. Rev. Fluid Mech., 31, 273–300. DOI: 10.1146/annurev.fluid.31.1.273.

Davidson P.A., 2001. An introduction to magnetohydrodynamics. Cambridge Uniwversity Press. DOI: 10.1017/CBO9780511626333.

Ergin F.G.,Watz B.B., Erglis K., Cebers A., 2015. Time-resolved velocity measurements in a magnetic micromixer. Exp. Therm Fluid Sci., 67. DOI: 10.1016/j.expthermflusci.2015.02.019.

Gao Y., 2013. Active mixing and catching using magnetic particles. Phd Thesis. Technische Universiteit Eindhoven. DOI: 10.6100/IR759475.

Gopalakrishnan S., Thess A., 2010. Chaotic mixing in electromagnetically controlled thermal convection of glass melt. Chem. Eng. Sci., 65, 5309–5319. DOI: 10.1016/j.ces.2010.07.008.

Hajiani P., Larachi F., 2014. Magnetic-field assisted mixing of liquids using magnetic nanoparticles. Chem. Eng. Process., 84, 31–37. DOI: 10.1016/j.cep.2014.03.012.

Hajiani P, Larachi F., 2013. Remotely excited magnetic nanoparticles and gas–liquid mass transfer in Taylor flow regime. Chem. Eng. Sci., 93, 257–265. DOI: 10.1016/j.ces.2013.01.052.

Hao Z., Zhu Q., Jiang Z., Li H., 2008. Fluidization characteristics of aerogel Co/Al2O3 catalyst in a magnetic fluidized bed and its application to CH4-CO2 reforming. Powder Technol., 183, 46–52. DOI: 10.1016/j.powtec.2007.11.015.

Harnby N., Edwards M.F., Nienow A.W., 1985. Mixing in the process industries. Butterworth-Heinemann. DOI: 10.1016/b978-0-7506-3760-2.x5020-3.

Hausmann R., Reichert C., Franzreb M., HöllW.H., 2004. Liquid-phase mass transfer of magnetic ion exchangers in magnetically influenced fluidized beds: II. AC fields. React. Funct. Polym., 60, 17–26. DOI: 10.1016/j.reactfunct polym.2004.02.007.

Hristov J., 2002. Magnetic field assisted fluidization – a unified aproach Part 1. Fundamentals and relevant hydrodynamics of gas-fluidized beds (batch solids mode). Rev. Chem. Eng., 18, 295–512. DOI: 10.1515/REVCE.2002.18.4-5.295.

Hristov J., 2007. Magnetic field assisted fluidization-Dimensional analysis addressing the physical basis. China Particuology, 5, 103–110. DOI: 10.1016/j.cpart.2007.03.002.

Hristov J., 2010. Magnetic field assisted fluidization – A unified approach. Part 8. Mass transfer: Magnetically assisted bioprocesses. Rev. Chem. Eng., 26, 55–128. DOI: 10.1515/REVCE.2010.006.

Hristov J.Y., 1998. Fluidization of ferromagnetic particles in a magnetic field Part 2: Field effects on preliminarily gas fluidized bed. Powder Technol., 97, 35–44. DOI: 10.1016/S0032-5910(97)03392-5.

Krakov M.S., 2020. Mixing of miscible magnetic and non-magnetic fluids with a rotating magnetic field. J. Magn. Magn. Mater., 498. DOI: 10.1016/j.jmmm.2019.166186.

Lange A., 2002.Kelvin force in a layer of magnetic fluid. J. Magn. Magn. Mater., 241, 327–329. DOI: 10.1016/S0304 -8853(01)01368-3.

Lu X., Li H., 2000. Fluidization of CaCO3 and Fe2O3 particle mixtures in a transverse rotating magnetic field. Powder Technol., 107, 66–78. DOI: 10.1016/S0032-5910(99)00092-3.

Moffatt H.K., 1965. On fluid flow induced by a rotating magnetic field. J. Fluid Mech., 22, 521–528. DOI: 10.1017/S0022112065000940.

Moffatt H.K., 1990. On the behaviour of a suspension of conducting particles subjected to a time-periodic magnetic field. J. Fluid Mech., 218, 509–529. DOI: 10.1017/S0022112090001094.

Moffatt H.K., 1991. Electromagnetic stirring. Phys. Fluids A, 3, 1336–1343. DOI: 10.1063/1.858062.

Molokov S., Moreau R., Moffat H.K., 2007. Magnetohydrodynamics. Historical evolution and trends. Springer Science+Business Media B.V. DOI: 10.1007/978-1-4020-4833-3.

Nouri D., Zabihi-Hesari A., Passandideh-Fard M., 2017. Rapid mixing in micromixers using magnetic field. Sens. Actuators, A, 255, 79–86. DOI: 10.1016/j.sna.2017.01.005.

Olivier G., Pouya H., Fadçal L., 2014. Magnetically induced agitation in liquid–liquid–magnetic nanoparticle emulsions: Potential for process intensification. AIChE J., 60, 1176–1181. DOI: 10.1002/AIC.14331.

Penchev I.P., Hristov J.Y., 1990. Fluidization of beds of ferromagnetic particles in a transverse magnetic field. Powder Technol., 62, 1–11. DOI: 10.1016/0032-5910(90)80016-R.

Poulsen B.R., Iversen J.J.L., 1997. Mixing determinations in reactor vessels using linear buffers. Chem. Eng. Sci., 52, 979–984. DOI: 10.1016/S0009-2509(96)00466-6.
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Authors and Affiliations

Rafał Rakoczy
1
ORCID: ORCID
Marian Kordas
1
ORCID: ORCID
Agata Markowska-Szczupak
1
ORCID: ORCID
Maciej Konopacki
1
ORCID: ORCID
Adrian Augustyniak
1
ORCID: ORCID
Joanna Jabłońska
1
Oliwia Paszkiewicz
1
ORCID: ORCID
Kamila Dubrowska
1
Grzegorz Story
1
Anna Story
1
Katarzyna Ziętarska
1
Dawid Sołoducha
1
Tomasz Borowski
1
Marta Roszak
2
Bartłomiej Grygorcewicz
2
ORCID: ORCID
Barbara Dołęgowska
2
ORCID: ORCID

  1. West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, al. Piastów 42,71-065 Szczecin, Poland
  2. Pomeranian Medical University in Szczecin, Chair of Microbiology, Immunology and Laboratory Medicine, Department of Laboratory Medicine, al. Powstańców Wielkopolskich 72, 70-111 Szczecin, Poland

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