Possible Sources and Impacts of Biochar Water Extractable Organic Compounds on Aquatic ...

172 Pages·2016·17.61 MB·English

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Chemistry & Biochemistry Theses &
Chemistry & Biochemistry
Dissertations
Summer 2016
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Cameron Russell Smith
Old Dominion University, [email protected]
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Smith, Cameron R.. "Possible Sources and Impacts of Biochar Water Extractable Organic Compounds on
Aquatic Microorganisms" (2016). Doctor of Philosophy (PhD), Dissertation, Chemistry & Biochemistry, Old
Dominion University, DOI: 10.25777/61vn-qx48
https://digitalcommons.odu.edu/chemistry_etds/10
This Dissertation is brought to you for free and open access by the Chemistry & Biochemistry at ODU Digital
Commons. It has been accepted for inclusion in Chemistry & Biochemistry Theses & Dissertations by an authorized
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POSSIBLE SOURCES AND IMPACTS OF BIOCHAR WATER EXTRACTABLE
ORGANIC COMPOUNDS ON AQUATIC MICROORGANISMS
by

Cameron Russell Smith
B.S. May 2011, Lynchburg College

A Dissertation Submitted to the Faculty of
Old Dominion University in Partial Fulfillment of the
Requirements for the Degree of

DOCTOR OF PHILOSOPHY

CHEMISTRY

OLD DOMINION UNIVERSITY
August 2016

Approved by:
James W. Lee (Director)
Patrick G. Hatcher (Member)
Lesley H. Greene (Member)
Sandeep Kumar (Member)
ABSTRACT

POSSIBLE SOURCES AND IMPACTS OF BIOCHAR WATER EXTRACTABLE
ORGANIC COMPOUNDS ON AQUATIC MICROORGANISMS

Cameron Russell Smith
Old Dominion University, 2016
Director: Dr. James W. Lee

Smokeless biomass pyrolysis with application of biochar as a soil
amendment could be a significant approach for carbon sequestration to possibly control
climate change for energy and environmental sustainability. If biochar were to be utilized
as a soil amendment and a carbon sequestration agent at Gt C scales, the release of
potentially toxic compounds into soils and associated hydrological systems, through soil
rainwater runoff and leaching, might have negative consequences, in both agro-
ecosystems and aquatic environmental systems. Therefore, the main focus of this
dissertation was to study the sources and chemical composition of biochar water
extractable (soluble) organic compounds and their effects on aquatic microorganisms.
To evaluate the effects of biochar water extractable substances on the
growth of aquatic microorganisms, rapid phytotoxicity assays were performed and
showed that pinewood derived biochar water extracts inhibited the growth of both
cyanobacteria, Synechococcus sp., and eukaryotic green algae, Desmodesmus sp., while
peanut shell and chicken litter derived biochar water extracts did not inhibit growth.
Because of its ultrahigh resolution, mass precision and effectiveness for analyzing water
soluble compounds, electrospray ionization (ESI) coupled to Fourier transform ion
cyclotron resonance mass spectrometry (FTICR-MS) was utilized to analyze biochar
water extracts at a molecular level to enhance our initial understanding of the toxic nature
of pinewood-derived biochar water extracts as compared to benign peanut shell-derived
biochar water extracts. The molecular composition of pinewood-derived biochar water
extracts showed unique carbohydrate ligneous components and sulfur containing
condensed ligneous components which were both absent from peanut shell-derived
biochar water extracts.
Finally, sources of biochar water soluble organic compounds (WSOC)
were investigated as a function of biomass materials including cellulose and lignin and
pyrolysis temperature from 300°C to 500°C in relation to their potential toxicity to
freshwater blue-green algae, Synechococcus. The amount of WSOC extracted from
biochar, irrespective of biomass starting material, decreased significantly as a function of
pyrolysis temperature. Algal bioassays and advanced 2D GC×GC mass spectrometry
analyses revealed that toxic WSOC extracted from pinewood-derived biochar was most
likely due to mono-, di- and tri-substituted phenolic compounds derived from lignin,
while toxic WSOC extracted from cellulose-derived biochar was acidic and bio-oil like in
nature.
iv

Copyright, 2016, by Cameron Russell Smith, All Rights Reserved.
v

This dissertation is dedicated
to my wonderful family and friends.
vi

ACKNOWLEDGEMENTS
First, I want to thank Old Dominion University for providing me with the
opportunity to pursue higher education in the field of chemistry. Secondly, the growth of
the chemistry program, the university and the community at ODU would not be what it is
today without the liberties the United States provides, and for that I am grateful.
I would like to thank my advisor, Dr. Lee, for his continual guidance and
patience throughout my post graduate education. His positive attitude and encouragement
are qualities that not only made him a great mentor, but also a friend. I would also like to
thank Dr. Hatcher for his guidance and collaboration over the course of my research. I am
very grateful that he allowed me to work closely with his group and share his laboratory.
I would also like to thank Dr. Rachel Sleighter for her support and mentoring throughout
my education. She has been one of the most influential teachers in my life, and for that I
am grateful. I would also like to thank Dr. Sandeep Kumar and Dr. Lesley Greene for
allowing me to use their laboratories for my research, and without both of them my
research would not have been possible. I would like to thank my group members, Matt
Huff and Hathiem Saeed, for their help and support throughout my studies. I would also
like to thank the Hatcher group members, specifically Amanda Willoughby, Derek
Waggoner, Wassim Obeid and Blaine Hartman, for their help and support. I would also
like to thank Isaiah Ruhl. All of these individuals have made my experience and
education at ODU more beneficial and enjoyable.
Lastly, and most importantly, I would like to thank God for all that I have,
and without him none of this would be possible.
vii

TABLE OF CONTENTS
Page

LIST OF TABLES ............................................................................................................. ix

LIST OF FIGURES .............................................................................................................x

Chapter

1. INTRODUCTION ...................................................................................................1
1.1 OVERVIEW ....................................................................................1
1.2 MOTIVATION ................................................................................1
1.3 GENERAL HYPOTHESES ............................................................3
1.4 ORGANIZATION OF CHAPTERS ...............................................4

2. BACKGROUND .....................................................................................................6
2.1 GENERAL .......................................................................................6
2.2 STRUCTURAL COMPONENTS OF BIOMASS ..........................8
2.3 BIOMASS PYROLYSIS ..............................................................10
2.4 BIOCHAR FORMATION .............................................................12
2.5 BIO-OIL FORMATION ................................................................13
2.6 POTENTIAL ROLE OF BIO-OIL ASSOCIATED WITH
BIOCHAR IN THE ENVIRONMENT .........................................14

3. POTENTIAL IMPACT OF BIOCHAR WATER-EXTRACTABLE
SUBSTANCES ON ENVIRONMENTAL SUSTAINABILITY ..........................17
3.1 INTRODUCTION .........................................................................18
3.2 MATERIALS AND METHODS ...................................................20
3.3 RESULTS AND DISCUSSIONS ..................................................33
3.4 CONCLUSION ..............................................................................55

4. MOLECULAR CHARACTERIZATION OF INHIBITING BIOCHAR
WATER-EXTRACTABLE SUBSTANCES USING ELECTROSPRAY
IONIZATION FOURIER TRANSFORM ION CYCLOTRON
RESONANCE MASS SPECTROMETRY ...........................................................57
4.1 INTRODUCTION .........................................................................58
4.2 MATERIALS AND METHODS ...................................................60
4.3 RESULTS AND DISCUSSIONS ..................................................65
4.4 CONCLUSION ..............................................................................91

5. AN INVESTIGATION INTO THE SOURCES OF BIOCHAR WATER
SOLUBLE ORGANIC COMPOUNDS AND THEIR POTENTIAL
TOXICITY ON AQUATIC MICROORGANISMS .............................................93
5.1 INTRODUCTION .........................................................................94
5.2 MATERIALS AND METHODS ...................................................95
viii

Chapter Page

5.3 RESULTS AND DISCUSSIONS ................................................102
5.4 CONCLUSION ............................................................................130

6. CONCLUSIONS AND FUTURE WORK ..........................................................132
6.1 IMPORTANCE OF BIOCHAR WATER SOLUBLE
(EXTRACTABLE) ORGANIC COMPOUNDS .........................132
6.2 GENERAL CONCLUSIONS ......................................................132
6.3 FUTURE WORK .........................................................................133

REFERENCES ................................................................................................................137

APPENDICES .................................................................................................................153
A. COPYRIGHT PERMISSION ......................................................153
B. ABBREVIATIONS AND ACRONYMS ....................................156

VITA ................................................................................................................................158
ix

LIST OF TABLES

Table Page

1. Dissolved organic carbon (DOC) in biochar water extracts. ........................................30

2. Electrodialysis separation of pinewood biochar water-extractable substances
(BWES) containing about 23.8 mg of dissolved organic carbon (DOC). ........................31

3. Biochar elemental (%, oven-dry wt. basis) and proximate analysis from
Galbraith Laboratories, Knoxville, TN. .............................................................................67

4. Comparison of elemental and proximate results with other reported biochar
analysis (%, oven-dry wt. basis). .......................................................................................68

5. Biochar yield, elemental analysis (oven-dry wt. % basis) and water soluble
organic compounds (WSOC) characteristics. ..................................................................103

6. Raw data biochar yields, elemental analysis (oven-dry wt. % basis) and water
soluble organic carbon characteristics. ............................................................................104

7. Compounds corresponding to total ion and extracted ion chromatograms in
Figure 33. .........................................................................................................................118

8. Qualitative analysis of volatile fraction via GC×GC MS. ..........................................122