THE ROLE OF ALGAE IN DISINFECTION PROCESSES IN WASTEWATER STABILIZATION ...

289 Pages·2017·17.97 MB·English

THE ROLE OF ALGAE IN DISINFECTION PROCESSES IN
WASTEWATER STABILIZATION PONDS

by

Lei Liu

A thesis submitted to the Department of Civil Engineering
in conformity with the requirements for
the Degree of Doctor of Philosophy

Queen’s University
Kingston, Ontario, Canada
January 2018

Copyright © Lei Liu, 2018
Abstract

This thesis is an investigation of pathogen removal in wastewater stabilization ponds
(WSPs). WSPs are sustainable alternatives to conventional wastewater treatment,
requiring minimal energy input and low costs. They have the capability to effectively
attenuate nutrients as well as pathogenic microorganisms. Disinfection in WSPs is a
complex process, which can be influenced by a number of mechanisms and
environmental factors, such as pH, dissolved oxygen (DO) and temperature. Due to long
retention time in these systems, algal activities are often expected during warm seasons.
Their presence may have effects on the complex interaction between biological
communities and water chemistry. This thesis aimed to assess the role of algae in
disinfection in WSP systems.

Two algae (Mougeotia sp. and Hydrodicty sp.) that were collected from the Amherstview
WSP were noted to increase both pH and DO when cultivated under laboratory
conditions. This finding was corroborated by the multivariate statistical analysis where
the correlation relationships between a wide range of water quality parameters (pH, DO,
temperature, chlorophyll, phycocyanin, Escherichia coli (E. coli), total coliforms (TC),
Enterococci, Clostridium perfringens (C. perfringens), ammonium, nitrate, total nitrogen,
phosphate total phosphorus and COD) were investigated. As such, the presence of algae
is believed to contribute to the high pH and DO levels in the WSP system.

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The inactivation of E. coli and total coliforms were found to increase with increasing pH.
Intermediate DO level (8.6 mg/L) appeared to support the survival of both E. coli and
total coliforms, while both high and low DO levels (20 mg/L and 1 mg/L, respectively)
could facilitate their removal and inactivation. This would suggest that the presence of
algae leading to high pH and DO could potentially promote the removal of E. coli, total
coliforms and Enterococci. Two additional indicator organisms (Enterococci and C.
perfringens) showed different inactivation trends compared to traditional indicator
organisms (E. coli, fecal coliforms or TC). C. perfringens were tolerant to the pH, DO
and temperature ranges investigated. They exhibited weaker correlations with both E. coli
and TC. This finding suggested that Enterococci and C. perfringens can be proposed as
potential indicator organisms.

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Co-Authorship

The work presented in this thesis was conducted by Lei Liu, with the assistance of co-authors
who provided technical support and guidance, and offered valuable comments and revisions to
the chapters. Chapters 2-6 are intended for publication in peer-reviewed journals. Appendix A
was published as a book chapter. Authorship and publication details are provided as follows:

• Chapter 2: Geof Hall and Pascale Champagne
o Manuscript to be submitted, in full, for publication in the Journal of
Environmental Reviews.

• Chapter 3: Geof Hall and Pascale Champagne
o Manuscript submitted in full, for publication in the Journal of Water.

• Chapter 4: Alan MacDougall, Geof Hall and Pascale Champagne
o Manuscript submitted in full, for publication in the Journal of Environments.

• Chapter 5: Geof Hall and Pascale Champagne
o Manuscript to be submitted, in full, for publication in the Journal of
Biotechnology.

• Chapter 6: Shuang Liang, Geof Hall and Pascale Champagne
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o Manuscript to be submitted, in full, for publication in the Journal of Water
Research.

• Appendix A: Pascale Champagne and Madeline Howell
o Appendix A was published as Chapter 7 in Part 1 Aerobic Treatment in the Book
of “Current Developments in Biotechnology and Bioengineering – Biological
Treatment of Industrial Effluents”.

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Acknowledgements

I would like to express my deepest gratitude and appreciation to my supervisors, Dr. Pascale
Champagne and Dr. Geof Hall. You have been tremendous mentors for me. Thank you for your
ongoing guidance, encouragement and support during my Ph.D. study at Queen’s University.

I would also like to acknowledge the financial support of the Natural Sciences and Engineering
Research Council (NSERC) and the STEWARD program, Loyalist Township and the Northern
Scientific Training Program.

For the Amherstview WPCP study, I would like to acknowledge the following people and
organizations for their assistance: MJ Merritt and Lori McFarland at Loyalist Township for their
assistance with sampling, site information and data collection; Dr. Steven Brown and Lynne
O’Donnell at the School of Environmental Studies and the Department of chemistry, Queen’s
University for providing assistance with sample analysis; Dr. Anna Majury and Kevin
McDermott at Public Health Laboratories in Kingston, Ontario for providing a laboratory space
and training.
I’m also thankful to my colleagues, in particular, Shijian Ge, Meng Jin, Rudy Schueder, Rami
Maassarani, Christine Gan, Alan MacDougall, Shuang Liang, Alxander Ray, Madeline Howell,
Max Madill, Rachel McConnell, Marlee Sauder, David Blair, Megan McKellar, Zoe
Zimmerman, Yumna Haseed for their help and support on this project.

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Lastly, I am indebted to my family, my parents, grandparents and my aunt and uncle for their
unconditional love and support. Their love, support and encouragement are always the strength
for me to overcome any obstacles in my life.

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Table of Contents

Abstract ........................................................................................................................................... ii!
Co-Authorship................................................................................................................................ iv!
Acknowledgements ........................................................................................................................ vi!
List of Figures .............................................................................................................................. xiii!
List of Tables ............................................................................................................................... xvi!
List of Nomenclature and Symbols ............................................................................................. xvii!
Chapter 1 Introduction .................................................................................................................... 1!
1.1 Background ........................................................................................................................... 1!
1.1.1 Wastewater stabilization ponds (WSPs) ........................................................................ 1!
1.1.2 Pathogens in Domestic Wastewater ............................................................................... 2!
1.1.3 Indicator Organisms ....................................................................................................... 4!
1.1.4 Algae photosynthesis, pH and dissolved oxygen (DO) ................................................. 6!
1.2 Research Scope and Objectives ............................................................................................ 7!
1.2.1 Study 1 - Selection of additional/alternative indicator organisms ................................. 8!
1.2.2 Study 2 – Correlations among algae growth, pH, DO, temperature and indicator
organisms ................................................................................................................................ 9!
1.2.3 Study 3 – Disinfection mechanisms and efficiencies of WSPs in temperate and Arctic
climates ................................................................................................................................. 11!
1.2.4 Study 4 - Effects of pH, DO and temperature on inactivation of bacterial, viral,
protozoan and helminthic indicator organisms (Bench study) ............................................. 12!
1.3 Organization of this thesis .................................................................................................. 13!
1.4 References ........................................................................................................................... 16!
Chapter 2 Disinfection Processes and Mechanisms in Wastewater Stabilization Ponds: A Review
....................................................................................................................................................... 23!
2.1 Abstract ............................................................................................................................... 23!
2.2 Introduction ......................................................................................................................... 24!
2.3 Wastewater Stabilization Ponds (WSPs) ............................................................................ 27!
2.4 Types of WSPs .................................................................................................................... 27!
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2.4.1 Anaerobic ponds .......................................................................................................... 28!
2.4.2 Facultative (Aerobic-anaerobic) ponds ........................................................................ 29!
2.4.3 Maturation ponds ......................................................................................................... 30!
2.5 Pathogen removal in WSPs ................................................................................................. 30!
2.6 Indicator organisms ............................................................................................................. 40!
2.6.1 Bacterial indicators ...................................................................................................... 40!
2.6.2 Viral indicators ............................................................................................................. 43!
2.6.3 Protozoan indicators ..................................................................................................... 44!
2.6.4 Helminthic indicators ................................................................................................... 45!
2.7 Factors affecting pathogen removal in WSPs ..................................................................... 46!
2.7.1 Sunlight ........................................................................................................................ 47!
2.7.1.1 Bacteria ................................................................................................................. 48!
2.7.1.2 Viruses .................................................................................................................. 49!
2.7.1.3 Protozoa ................................................................................................................ 51!
2.7.2 pH ................................................................................................................................. 53!
2.7.3 DO ................................................................................................................................ 55!
2.7.4 Temperature ................................................................................................................. 57!
2.7.5 Attachment & Sedimentation ....................................................................................... 59!
2.7.6 Retention time & Pond depth ....................................................................................... 60!
2.7.7 Predation & Presence of other microorganisms ........................................................... 62!
2.7.8 Nutrients and organic loading ...................................................................................... 64!
2.8 Conclusions ......................................................................................................................... 64!
2.9 References ........................................................................................................................... 67!
Chapter 3 Effects of Environmental Factors on the Disinfection Performance of a Wastewater
Stabilization Pond Operated in a Temperate Climate ................................................................... 93!
3.1 Abstract ............................................................................................................................... 93!
3.2 Introduction ......................................................................................................................... 93!
3.3 Material and Methods ......................................................................................................... 96!
3.3.1 System Overview ......................................................................................................... 96!
3.3.2 Field Monitoring and Sampling ................................................................................... 97!
3.3.3 Statistical Analysis ....................................................................................................... 98!
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3.4. Results and Discussion ...................................................................................................... 99!
3.5 Conclusion ........................................................................................................................ 108!
3.6 References ......................................................................................................................... 110!
Chapter 4 Disinfection performance in wastewater stabilization ponds in cold climate conditions:
a case study in Nunavut, Canada ................................................................................................ 115!
4.1 Abstract ............................................................................................................................. 115!
4.2 Introduction ....................................................................................................................... 116!
4.3 Materials and Methods ...................................................................................................... 119!
4.3.1 Study site .................................................................................................................... 119!
4.3.2 Assessment of water quality ...................................................................................... 120!
4.3.3 Detection of indicator organisms ............................................................................... 121!
4.3.4 Modelling disinfection ............................................................................................... 122!
4.4 Results ............................................................................................................................... 127!
4.4.1. WSP performance ..................................................................................................... 127!
4.4.2. Comparative analysis of disinfection models ........................................................... 129!
4.5. Discussion ........................................................................................................................ 131!
4.6. Conclusion ....................................................................................................................... 134!
4.7 References ......................................................................................................................... 135!
Chapter 5 The Role of Algae in the Removal and Inactivation of Pathogenic Indicator Organisms
in Wastewater Stabilization Pond Systems ................................................................................. 140!
5.1 Abstract ............................................................................................................................. 140!
5.2 Introduction ....................................................................................................................... 141!
5.3 Material and Methods ....................................................................................................... 144!
5.3.1. Source of wastewater samples .................................................................................. 144!
5.3.2. Algae cultivation experiments .................................................................................. 145!
5.3.3. pH experiments ......................................................................................................... 146!
5.3.4 DO experiments ......................................................................................................... 147!
5.3.5 Temperature experiments ........................................................................................... 148!
5.3.6 Statistical analysis ...................................................................................................... 148!
5.4 Results and Discussion ..................................................................................................... 149!
5.5 Conclusion ........................................................................................................................ 159!
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