Inhibitory Effect of Copper Precipitates on Anaerobic Biological Sulfate Reduction

189 Pages·2017·7 MB·English

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Electronic Theses and Dissertations Theses, Dissertations, and Major Papers
2017
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Shahrokh Shahsavari
University of Windsor
Follow this and additional works at: https://scholar.uwindsor.ca/etd
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Shahsavari, Shahrokh, "Inhibitory Effect of Copper Precipitates on Anaerobic Biological Sulfate Reduction"
(2017). Electronic Theses and Dissertations. 6016.
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Inhibitory Effect of Copper Precipitates on Anaerobic Biological Sulfate Reduction
by
Shahrokh Shahsavari
A Thesis
Submitted to the Faculty of Graduate Studies
Through Civil and Environmental Engineering
in Partial Fulfillment of the Requirements for
the Degree of Doctor of Philosophy at the
University of Windsor
Windsor, Ontario, Canada
2017
© 2017 Shahrokh Shahsavari
Inhibitory Effect of Copper Precipitates on Anaerobic Biological
Sulfate Reduction
by

Shahrokh Shahsavari

APPROVED BY:

______________________________________________
G. Achari, External Examiner
University of Calgary

______________________________________________
I. Al-Aasm
Department of Earth and Environmental Science

______________________________________________
P. Henshaw
Department of Civil and Environmental Engineering

______________________________________________
E. Tam
Department of Civil and Environmental Engineering

______________________________________________
R. Seth, Co-advisor
Department of Civil and Environmental Engineering

___________________________________________
N. Biswas, Co-advisor
Department of Civil and Environmental Engineering

March 2nd, 2017
DECLARATION OF ORIGINALITY
I hereby certify that I am the sole author of this thesis and that no part of this thesis has
been published or submitted for publication.
I certify that, to the best of my knowledge, my thesis does not infringe upon anyone’s
copyright nor violate any proprietary rights and that any ideas, techniques, quotations, or
any other material from the work of other people included in my thesis, published or
otherwise, are fully acknowledged in accordance with the standard referencing practices.
Furthermore, to the extent that I have included copyrighted material that surpasses the
bounds of fair dealing within the meaning of the Canada Copyright Act, I certify that I
have obtained a written permission from the copyright owner(s) to include such
material(s) in my thesis and have included copies of such copyright clearances to my
appendix.
I declare that this is a true copy of my thesis, including any final revisions, as approved
by my thesis committee and the Graduate Studies office, and that this thesis has not been
submitted for a higher degree to any other University or Institution.

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ABSTRACT
Biological anaerobic sulfate reduction to sulfide by sulfate reducing bacteria (SRB) can
be performed in a single-stage reactor in which the biological sulfate reduction to sulfide
and metal precipitation occur simultaneously, or in two-stage reactors where the two
follow sequentially.
The single stage process may be more cost-effective and simpler to operate. However,
some factors, such as acidic nature of acid mine drainage (AMD) and the presence of the
residual heavy metals in the system may pose an inhibitory and toxic effect on SRB and
limit the application of the process. In addition, some studies suggest that beyond a
certain level of metal loading, the process of sulfate reduction and the corresponding
metal precipitation by the sulfide generated is adversely affected.
In the first part of this study, the effect of different concentrations of copper on anaerobic
sulfate reduction in semi continuous stirred tank reactors (SCSTRs) at 35±2ºC was
investigated. Four parallel SCSTRs received synthetic wastewater containing copper at
various concentrations. They were optimized for pH and were operated at a
predetermined COD/SO42-. Reactors receiving lower concentration (< 200 mg/L) of
copper showed a very little negative effect in their performance. However, at higher
concentrations (> 400 mg/L), performance was inhibited, which could be attributed to the
presence of metal precipitates in these reactors. Batch kinetic experiments confirmed this
inhibition of the sulfate reduction process in the presence of high concentration of metal
precipitates. The cultures withdrawn at various process conditions were analyzed for their
respective microbial pattern. It showed that certain concentrations of copper precipitates
adversely affected the population of sulfate reducers. Reactors receiving 0 mg/L and 200
mg/L of copper showed more similarity in terms of their respective sulfate reducers’
population. The presence of thiosulfate reducers in microbial community may be an
evidence for the existence of an alternate pathway in dissimilatory anaerobic sulfate
reduction that generates thiosulfate as the intermediate byproducts during the reduction of
sulfite to sulfide.

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In the second part of the study, two upflow anaerobic hybrid reactors (UAHR) were
designed to overcome the inhibition of SRB by the metal precipitates. Two identical
UAHRs received simulated wastewater with COD/SO 2- of 1, where the sulfate
4
concentration was 3040 mg/L. One UAHR was used to represent the single-stage process,
and the influent contained metal (copper) in the feed. The other UAHR represented the
first stage of the two-stage process. The performance of the two processes was compared
over different hydraulic, organic, and sulfate loading rates by varying the HRT between
40 and 2.5 days at a temperature of 33±3°C. The results show that both sulfate reduction
and copper precipitation in the single stage process were similar to or better than the two-
stage process over the entire duration of the study. The rate of copper removal in the
single stage process was found to reach up to two times of that of the two stage process.
This suggests that the proposed UAHR configuration was successful in overcoming the
inhibition of SRB by the metal precipitates.
In the single stage reactor for which S/Cu was higher than 1, copper was precipitated in
the form of CuS. The same happened for the second stage of two stage process once S/Cu
was set to be higher than 1. This was confirmed with the equilibrium calculations using
MINTEQ speciation model. However, the results of the MINTEQ showed that at S/Cu of
less than 1, additional amount of copper is precipitated in the forms of Cu (PO ) and
3 4 2
CuO.

v
DEDICATION

This is dedicated to

my proud parents
Mohammad Hossein Shahsavari
and
Akram Azizmohammadi

and

my wife
Maryam Shahabi Far

For their unconditional love, encouragements and supports

vi
ACKNOWLEDGEMENTS
I would like to appreciate my advisors Dr. Nihar Biswas and Dr. Rajesh Seth for their
advices, supports and criticism throughout the entire of this research.
I would also like to extend my thanks to my dissertation committee members; Dr. Gopal
Achari, Dr. Ihsan Al-Aasm, Dr. Paul Henshaw and Dr. Edwin Tam for taking their
valuable times to review this work and making constructive suggestions.
Financial supports to this research was furnished via National Science and Engineering
Research Council (NSERC) discovery grants to Dr. Nihar Biswas and Dr. Rajesh Seth,
University of Windsor tuition scholarship, Queen Elizabeth II scholarship, Ontario
graduate scholarship and University of Windsor graduate student society award.
I would also like to thank Dr. Fereydoun Ghazban for taking his time to read this
dissertation. His constructive comments are greatly appreciated. Sharon Lackie is greatly
appreciated for SEM/EDS analysis of my samples at GLIER institute. I also thank
Melissa Price at the department of Earth Science and Dr. S. Holger Eichhorn and his
lab’s members at the department of Chemistry for sharing their knowledge on XRD
analysis and conducting XRD analysis of the samples. Many thanks to Dr. Subba Rao
Chaganti at GLIER institute for providing the microbial data of the samples and sharing
his valuable knowledge to interpret the data.
I am extremely grateful to the staff members of the department of Civil and
Environmental Engineering: Catherine Wilson, Diane Hibbert, Rosa Campeau, Sandra
Mehenka, Rosemarie Gignac and Ashley Holiga with the especial thanks to Bill
Middleton for all his helps, assistance and motivations during the long days in the lab and
Matt St. Louis for those nice fabrication works.
Throughout the years at the University of Windsor, I was blessed to have so many
amazing colleagues and peers. The list would be too long if I want to mention all but I
would like to name Sailesh Singh, Rajan Ray, Wei Feng, Andrew Schoof and Wudneh
Ayele Shewa. I thank you very much guys for all the moments that we shared together.
During my time at this university, I had the opportunity to work with and train many
undergraduate students at water and wastewater laboratory. Some of them helped me a lot

vii
during the loaded experimental plans and I would like to specifically thank Yasser
Hamadani and Christina Ure for all their efforts throughout my lab work.
My heartfelt thanks go out to my parents and my sisters, Nooshin and Shirin for always
believe in me and their supports and encourages.
When I started my PhD on May 2011, I would never imagine that it will take almost six
years. During this long time and its ups and downs, I was lucky enough to have a great
companion, my beloved wife Maryam. This would have not been possible without her
constant presence, unconditional love, supports and encouragements. Our son Rodin was
born during this time bringing us the most wonderful feeling. All the happy moments that
he created, eased the difficulties that I had throughout this research.

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TABLE OF CONTENTS
DECLARATION OF ORIGINALITY…………………………………………………..iii
ABSTRACT……………………………………………………………………………...iv
DEDICATION……………………………………………………………………….…..vi
ACKNOWLEDGEMENTS……………………………………………………………..vii
LIST OF TABLES………………………………………………….……………………xv
LIST OF FIGURES……………………………………………………...……………..xvii
LIST OF ELECTRONIC APPENDICES……………………………………………….xxi
LIST OF ABBREVIATIONS…………………………………...…….……………….xxii
CHAPTER ONE: INTRODUCTION
1.1 Introduction………………………………………………………..1
1.2 Removal of Heavy Metals by Biogenic Sulfate Reduction
Process…….………………………………………………………4
1.3 Objectives…………………………………………………………5
1.4 Scope of the Work………………………………………………...6

CHAPTER TWO: LITERATURE REVIEW
2.1 Sources of Heavy Metal Contamination……….………………….7
2.1.1 Natural Sources of Heavy Metals………………..…….………….7
2.1.2 Anthropogenic Sources of Heavy Metals………..………………..8
2.1.2.1 Agricultural Activities…………………..………………...………8
2.1.2.2 Industrial Wastes……………………….…………………………9
2.1.2.3 Domestic Waste Streams……………………..…………………...9
2.1.2.4 Mining Activities………….……………………………………...9
2.2 Treatment Options for Wastewater Containing Heavy Metals…..11
2.2.1 Adsorption……………………………...………………………...12
2.2.2 Membrane Filtration……………………...……………………...12
2.2.3 Coagulation-Flocculation………………...………………………14
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