Virus removal in ceramic depth filters [Elektronische Ressource] / vorgelegt von Benjamin Michen

Informations

• Publié par: technische_universitat_bergakademie_freiberg
• Publié le: 01 janvier 2010
• Nombre de lectures: 22
• Langue: English
• Poids de l'ouvrage: 3 Mo

Extrait

Virus removal in ceramic depth filters:
The electrostatic enhanced adsorption approach

der Fakultät für Maschinenbau, Verfahrens- und Energietechnik
der Technischen Universität Bergakademie Freiberg
genehmigte
DISSERTATION
zur Erlangung des akademischen Grades
Doktor-Ingenieur
(Dr.-Ing.)
vorgelegt


von Diplom Ingenieur (FH), Benjamin Michen
geboren am 29.07.1981 in Tübingen
Freiberg, den 1.12.2010






























...to all those who suffer from water contaminated with viruses.


Acknowledgements
This research was conducted in collaboration between the Laboratory for High Performance
Ceramics at the Swiss Federal Laboratories for Materials Science and Technology (EMPA) in
Switzerland, the Institute of Ceramic, Glass and Construction Materials at the Technical
University “Bergakademie” in Freiberg, Germany and the Technology and Management Faculty of
the University of Applied Sciences in Ravensburg-Weingarten, Germany. Financial support
provided by an industrial partner as well as by internal funding of the EMPA enabled this research,
for which I am exceptionally grateful.
I am especially indebted to Prof. Dr. Ing. C. G. Aneziris, Prof. Dr. rer. nat. T. J. Graule and
Prof. Dr. rer. nat. J. Firtsch for the opportunity provided. Additionally, I appreciate their critical
questions, important advice and valuable suggestions during this work.
Furthermore, I would like to acknowledge the contribution of Natasa Rittiner, as her
support in carrying out a tremendous amount of bacteriophage tests was priceless. My wife,
Marina, who patiently listened to various theories of mine, has also been very valuable in proof-
reading the manuscript. Next, thanks go to Brain Sinnet from Eawag for his steady support on the
DLS equipment.
In particular, I express my gratitude to the students who carried out their trainee, Diploma
or Master’s theses over the course of this project: Steffen Schnabel, Fabian Meder, Christian Weigelt
and Annegret Lies. Their work has always been very inspiring.
Additionally, I am grateful to those who supported me in the lab: Hans Jürgen Schindler,
Salvatore Fuso and Noemie van Garderen.
Last, but certainly not least, I am grateful for the continual encouragement and support of
my family.

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Contents
Chapter I Introduction.................................................................................................. 1
Chapter II Removal or inactivation of microorganisms, in particular viruses, for
drinking water purposes with focus on small-scale, decentralised
systems: A literature review ...................................................................... 7
II. I Physical and chemical treatments.......................................................................... 8
II. II Filtration processes.............................................................................................. 10
II. III Conclusions ......................................................................................................... 15
Chapter III Mechanisms of adsorption in depth filtration ......................................... 17
III.I Surface charge and the electrical double layer .................................................... 18
III.II van der Waals interactions................................................................................... 22
III.III DLVO theory ........................................................................................................ 23
III.IV Non-DLVO forces................................................................................................. 25
III.V Extended DLVO Theory....................................................................................... 27
Chapter IV Virus adsorption studies........................................................................... 29
IV.I A literature review ................................................................................................ 30
IV.I.I Virus concentration by adsorption-elution ...................................................................33
IV.I.II Improved virus adsorption in filtration .........................................................................35
IV.II The electrostatic enhanced adsorption approach ................................................ 37
Chapter V Viruses........................................................................................................ 39
V.I Literature review .................................................................................................. 40
V.I.I Structure and morphology...........................................................................................40
V.I.II The viral life cycle41
V.I.III Human pathogenic viruses in the aquatic environment ..............................................42
V.II Experimental........................................................................................................ 46
V.II.I The choice of viruses for adsorption studies...............................................................46
V.II.II Propagation and enumeration of the bacteriophages .................................................48
V.II.III Characterisation of bacteriophages ............................................................................51
V.III Results and discussion ........................................................................................ 54
V.III.I Production of high-titre and high-purity phage stocks54
V.III.II Characteristics of bacteriophages...............................................................................59
V.III.III Detection of a viral contaminant - the ‘Siphophage’....................................................64
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Chapter VI The diatomaceous earth-based depth filter............................................. 69
VI.I Literature review .................................................................................................. 70
VI.I.I Diatomaceous earth ................................................................................................... 70
VI.I.II Retention of microorganisms in the DE-based depth filter ......................................... 71
VI.II Experimental........................................................................................................ 73
VI.II.I Manufacturing the depth filter ..................................................................................... 73
VI.II.II Physical characterisation............................................................................................ 74
VI.II.III Performing filter retention tests................................................................................... 75
VI.II.IV Latex retention test ..................................................................................................... 76
VI.II.V Studying adsorption kinetics in a batch experiment ................................................... 79
VI.II.VI Applying (X-)DLVO theory .......................................................................................... 80
VI.III Results and discussion ........................................................................................ 83
VI.III.I Characterisation of the depth filter.............................................................................. 83
VI.III.II Latex removal in the depth filter ................................................................................. 86
VI.III.III Filter performance on virus removal ........................................................................... 94
VI.III.IV Batch-sorption experiments 99
VI.IV Summary and conclusions 102
Chapter VII The magnesium oxide modified depth filter.......................................... 103
VII.I Experimental...................................................................................................... 104
VII.I.I Choice of the adsorbent material.............................................................................. 104
VII.I.II Manufacturing the MgO-modified filter and characterisation methods ..................... 105
VII.II Results and discussion ...................................................................................... 106
VII.II.I The adsorbent: Magnesium oxide powder ............................................................... 106
VII.II.II Physical characterisation of modified depth filters.................................................... 108
VII.II.III Virus removal in depth filters containing MgO .......................................................... 113
VII.II.IV Ageing behaviour of MgO modified filters................................................................. 118
VII.II.V Discussion on the removal mechanisms .................................................................. 130
VII.III Summary and conclusions................................................................................. 134
Chapter VIII Summary, conclusions and outlook ...................................................... 135
VIII.I Summary and conclusions 136
VIII.II