ORAL O1 – Paisley Thomson Consequences of a - Langlois-Lab

ORAL
O1 – Paisley Thomson
Consequences of a feed additive (melengestrol acetate) exposure in frogs
Gestagens, which include endogenous and synthetic progesterone receptor ligands used in
human and veterinarian drugs, are an emerging class of contaminants that have been recently
measured in surface water in North America. Endogenous progestogens are essential in the
regulation of reproduction in mammalian species and recent studies have demonstrated that
environmental gestagens have the ability to also interfere with the reproduction in aquatic
vertebrates. This project aims to understand the roles and the regulation mechanisms of
progesterone in amphibians and to assess the consequences of exposures to environmental
gestagens on the progesterone receptor signaling pathways in frogs. This study 1) will establish
the developmental profile of the progesterone receptors in Silurana tropicalis embryos using in
situ hybridization and real-time RT-PCR techniques and 2) will assess the effects of progesterone
and melengestrol acetate in amphibian early development and at metamorphosis in order to
analyze change in the expression change of a suite of gene targets of interest (including, pgr,
pgrmc1, 3β-hsd, ar, er, fshβ, prl, and srd5α). Developmental gene expression profiles for pgr and
pgrmc1 will be presented.
O2 – Shawna Corcoran
Detecting anti-estrogens and anti-androgens in surface waters impacted by municipal
wastewater discharge and agricultural run-off
Few studies have been done to evaluate whether chemicals with anti-estrogenic and antiandrogenic activity are released into surface waters from both wastewater discharge and
agricultural run-off. These chemicals have the potential to adversely affect the development of
aquatic organisms, therefore the presence and the fate of anti-androgenic and anti-estrogenic
compounds in watershed areas requires further investigation. This project investigated whether
a variety of chemicals with known anti-androgenic and anti-estrogenic activity are present in
surface waters as a result of agricultural run-off and municipal wastewater discharges. The
project focuses on monitoring surface waters in southern Ontario and in Argentina that are
impacted by both sources. Analytical methods were developed to detect a variety of antiandrogenic and anti-estrogenic compounds of pharmaceutical and pesticide origin in surface
waters and wastewater. The concentrations of these chemicals were monitored in composite
samples collected throughout the Guelph WWTP and grab samples of surface water in the Speed
River, as well as by deploying Polar Organic Chemical Integrative Samples (POCIS) in the
watersheds. Quantification and identification of the compounds from the collected samples were
conducted using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS).
Preliminary data with POCIS monitoring indicate that a variety of fungicides with anti-androgenic
activity were detected in the watersheds in Argentina. In addition to other pesticides of
agricultural origin. Analysis of POCIS deployed in the Speed River, ON indicated that the antiandrogen used for cancer therapy, cyproterone acetate, respectively, was present in surface
waters. The project will contribute to an understanding of whether anti-estrogens and antiandrogens are a hazard to aquatic organisms in watersheds.
O3 – Prettiny Ma
Modeling the formation and aging of secondary organic aerosols in polluted urban regions
According to the most recent report published by the Intergovernmental Panel on Climate
Change (IPCC), atmospheric aerosols (i.e. particulate matter or PM) represent a major source of
uncertainty in climate models. In addition, elevated concentrations of PM, which is one of the
most important air pollutants, are linked to reduced life expectancies. Secondary organic aerosols
(SOA) are formed in the atmosphere from gaseous precursors through oxidation reactions, and
they represent a major component of the total PM mass globally. To better understand the
chemical pathways responsible for SOA formation, a box model is designed to simulate
dynamically the evolution of organic species in an air parcel as it undergoes photochemical
oxidation, therefore producing SOA. The model incorporates recently published
parameterizations for the formation of SOA from volatile organic compounds, as well as from
semi-volatile and intermediate-volatility organic compounds. The model is constrained by
measurements of precursors and the predications are compared against measurements of SOA
taken in Southern California during that CalNex campaign. Predictions of the SOA mass were
biased low at shorter photochemical ages when compared to field measurements, but at longer
ages model/measurements agreement is observed. The results of this study also indicate that
some recently proposed literature parameterizations for the production of SOA may overpredict
concentrations due to poorly constrained concentrations of intermediate-volatility organic
compounds, which are an important class of precursors. Also it was shown that cooking emissions
might be a potential SOA precursor.
O4 – Nicholas Maya
Assessing the effectiveness of ozonation technologies for reducing the toxicity to fish of
contaminants of emerging concern in wastewater
Pharmaceutical and personal care products (PCPPs) are biologically active compounds which are
of concern fir their potential to induce toxic effects in aquatic organisms at environmentally
relevant concentrations. Conventional treatment technologies are not designed to remove these
contaminants of emerging concern (CECs) from wastewater and thus, do no necessarily reduce
impacts on aquatic organisms. Working with colleagues from McGill University and an industrial
partner, Air Liquide, we investigated the lethal and sub-lethal toxicity to fish of PCPPs commonly
found in municipal wastewaters in order to evaluate the effectiveness of ozonation technologies
in reducing the toxicity of CECs to fish. Early life stages of Japanese medaka (Oryzias latipes) were
exposed to five model PCPP compounds, and to extracts prepared from ozonated and nonozonated wastewater spiked with the model compounds. Toxicity to medaka was assessed in
terms of mortality, hatching success and developmental responses. Juvenile rainbow trout
(Oncorhynchus mykiss) were intraperitoneally injected with positive control compounds, a PCPP
mixture, and ozonated and non-ozonated wastewater extracts spiked with the five model
compounds. At 72 hours post-exposure, the liver, kidney, brain and blood were collected from
the trout to assess sub-lethal toxicity in terms of biomarker responses including lipid
peroxidation, total glutathione, cytochrome P4501A and cytochrome P4503A activity,
modulation of plasma steroids, induction of vitellogenin, and alterations in the level of
bioenergetics molecules and neuroactive amines. Study results will be discussed in relation to
the potential for ozonation to be used as a treatment method for reducing the toxicity of CECs in
municipal wastewater.
O5 – Mija Azdajic
Cycling of mercury in the area surrounding giant mine
Mercury (Hg) is a global pollutant that bioaccumulates in the food webs of aquatic and terrestrial
ecosystems in form of monomethylmercury (MMHg). Microbial activity is the main source of
MMHg production, with sulfate reducing bacteria (SRB) being the main contributors. MMHg is
then available to other organisms in the foodweb. MMHg is a potent neurotoxin, and as such
predicting its fate in the environment is important for addressing ecosystem and human health
concerns. Residents of Canada's northern regions are vulnerable to the impacts of MMHg
exposure due to their dependence on local food sources, their main route of exposure. Further
increasing the risk of Hg exposure is the presence of mining operations such as Yellowknife's
Giant Mine. This mine is associated with considerable pollution in the surrounding area namely
due to the roasting of arsenopyrite. The roasting has created strong environmental gradients
with respect to sulfate concentrations in lakes which decrease with distance from the mine.
Although total Hg levels remain constant with increasing distance from the mine, MMHg levels
were greater closer to the mine. To identify drivers of MMHg production, we are planning on
using stable Hg isotope tracers during incubation experiment following an orthogonal sampling
design with varying sulfate, DOC, and phosphate concentrations; we also characterized microbial
community structure of the affected sites using 16S rRNA gene amplicons high throughput
sequencing.
O6 – Gwyneth MacMillan
Influence of permafrost thaw and ice-wedge polygon formation on the mercury cycle within
artic lakes and ponds
Thermokarst ponds are ubiquitous in the Canadian Arctic and may proliferate in some regions
with climate change. Previous research has shown that thaw ponds can be hotspots of microbial
activity, with elevated levels of methylmercury (MeHg). However their potential as sources of
MeHg to downstream water bodies is unknown. Permafrost thaw can lead to greater hydrological
connectivity, increasing potential transport of thaw pond MeHg to other ecosystems. To
investigate whether thaw polygon formation in lake catchments affects the transport of inorganic
mercury (Hg) and MeHg, 9 lakes were sampled near Inuvik in the Northwest Territories. These
lakes are located adjacent to the Mackenzie River Basin, an area currently undergoing rapid
climate warming. Thermokarst lakes were sampled for water chemistry (nutrients, ions and trace
metals) and sediment cores were taken for paleolimnological analyses of Hg. Preliminary results
show that thaw polygons in lake catchments from this region have conditions highly conducive
for microbial Hg(II) methylation (high DOC, low pH, low O2), and show very high levels of total
and %MeHg (0.5 – 3.6 ng/L, 7.0- 42.8%). In comparison to a nearby reference lake (with no
polygon influence), the lakes with ice-wedge polygons in their catchments show significantly
higher levels of Hg and MeHg in surface waters (p<0.01) and higher concentrations of sediment
Hg. Further, the sediment Hg profiles indicate a marked increase in the surface layers, suggesting
greater Hg inputs to the lake in recent years. Sediment profiles of MeHg concentrations will also
be presented. Overall, our preliminary findings suggest that thaw ponds may be a significant
source of mercury to downstream lakes.
O7 – Sean Winland-Gaetz
A closer look at the biogeochemical controls of mercury methylation in contaminated systems
The complex biogeochemical cycling of mercury, and particularly its microbial conversion to the
highly toxic form methylmercury, is still imperfectly understood, impeding management of
contaminated systems. Many microbes involved in mercury methylation rely on sulfate and iron
reduction in their metabolic strategies, tightly linking iron-sulfur cycling and sediment organic
carbon to the net production of methylmercury. Much of the literature to date is relatively
narrow in scope, concerning trends in individual geochemical cycles or pure-culture mercurymethylating processes. This project aims to relate interactions of iron/sulfur biogeochemical
cycling and microbial community structure to methylmercury production in contaminated
freshwaster and estuarine sediments. To obtain a representative profile of spatially-stratified
processes occurring in natural systems, microcosms containing mercury-contaminated sediment
were fitted with pore water samplers that can be refilled and resampled non-invasively. Pore
water and sediment cores were extracted weekly over the course of five weeks, with a sulfate
spike added following the second week to assess the impacts of SRB stimulation. Pore water was
analyzed for major iron (FE2+, Fe3+) and sulfur (SO4, ΣH2S, S0/SO3/S2O3) redox species and
intermediates, to follow changes in microbial iron and sulfur reduction. Sediment cores were
assessed for solid mercury phase (MeHg/THg) and metagenomics profiling of the microbial
community through shotgun sequencing and analysis (pending). I will be presenting our key initial
findings from this study. This work was conducted in collaboration with the Amyot lab at the
Université de Montréal, and Geosyntec Consultants through the NSERC CREATE Mine of
Knowledge program.
O8 – Maeve Moriarty
Arsenic sorption to bacteriogenic iron oxide (BIOS)
Bacteriogenic iron oxides (BIOS) contain up to 35% organic matter which is rich in
polysaccharides. BIOS form in water-rock interfaces and are important sorbants for cationic
metal ions. BIOS form wherever anoxic water rich in iron surface, such as in mine seep
environments where arsenic concentrations may be elevated. Arsenic is naturally sorbed by iron
in sediments but there is evidence that arsenic also interacts and immobilized by organic matter
in BIOS. We are interested in how arsenic behaves within these biogenic iron systems and how
the organic matter affects arsenic binding and immobilization through both direct interaction
with arsenic and through modification of the iron surface. We are looking at arsenic sorption to
an iron/polysaccharides precipitate (to model BIOS) using the commercially available alginic acid
at a range of Fe:organic matter ratios. This sorption profile will then be compared with arsenic
sorption to an iron/polysaccharides precipitate using polysaccharides extracted from fieldcollected BIOS from both a mining-impacted source and a background source. Two field sources
of polysaccharides were chosen to account for variability in organic matter in BIOS at different
sites. We will determine whether alginic acid is a good model for the organic matter in BIOS, as
well as see how much the adsorption capability of the exopolysaccharides varies between
naturally occurring BIOS.
O9 – Martin Pothier
Development of a quantitative lab and field based microbial tool to determine arsenic
speciation
Arsenic pollution raises serious public health concerns worldwide. Whether arsenic is released in
the environment by geogenic or anthropogenic sources, it remains an unstable, redox sensitive
molecule that can be modified by microbes, generating several organic and inorganic arsenic
species. Determining the speciation of arsenic is crucial in predicting its mobility, bioavailability
and toxicity.
The tools available for risk management include chemical field kits and several analytical
techniques such as AAS or ICP-MS. Although these are well established methods, analytical
techniques are limited by their portability and field kits lack the ability to determine the
speciation of arsenic.
Over the past 30 years, whole-cell biosensor assays have been designed to detect the presence
and quantify a variety of chemicals and toxic metals. Bacterial reporters are customizable and
reliable for the measurement of the biologically relevant fraction of contaminants. Here we have
designed a novel arsenic biosensor that is portable and able to determine Arsenic speciation at
concentrations below the World Health Organization's guidelines for arsenic in drinking water.
O10 – Kirsten Maitland
Arsenic in soil in the Yellowknife region
Legacy mining activities within and around the City of Yellowknife have resulted in significant
land and water contamination. The roasting of gold-bearing arsenopyrite (FeAsS) ore at Giant
Mine resulted in the release of approximately 20,000 tonnes of arsenic trioxide (As 2O3) into the
surrounding environment. To assist in characterizing the extent of contamination caused by
mining activities, regional scale data representative of potentially unimpacted and impacted
areas has been collected to compare their differences in soil geochemistry.
Over a period of six weeks, 175 soil samples were collected from four terrain units found within
a 30 km radius of Yellowknife; outcrop soils, forested canopy soils, wetland soils, and peat. Target
areas for soil sampling were selected based on distance from the former Giant roaster, direction
from the roaster with respect to prevailing wind direction, and location with respect to past or
on-going research.
Total element analyses by ICP-MS and ICP-OES will be completed on the upper 5cm of soil
collected from each sample site. Select cores, chosen for SEM-MLA analysis, will be used to
identify the species of arsenic present within the soil units. Anthropogenic sources of arsenic will
be characterized by a presence of As2O3 and As-bearing iron (Fe)-oxides derived from roaster
stack emissions.
A regional-scale soil sampling initiative complements previous geochemical surveys undertaken
throughout the area. This research will work towards understanding the connections between
terrestrial and aquatic systems in the region by filling knowledge gaps in soil geochemistry and
mineralogy.
O11 – Elise Morel
Should CeO2 nanoparticles be considered differently than ionic Ce in risk evaluations?
With the growing number of applications that use rare earth elements (REE), it is expected that
manufactured forms of these elements will be rejected into the natural environment. Cerium
(Ce) is a REE that is used in several forms including ionic (e.g. Ce3+) or nanoparticulate forms (e.g.
CeO2 NPs). Unfortunately, even now it is not clear whether the biological responses of organisms
exposed to nanoparticles are induced by the nanoparticles themselves or by the ionic fraction of
Ce that can co-occur in the nanoparticle suspensions. Biological responses at a molecular and
organism levels were measured for the unicellular freshwater alga, Chlamydomonas reinhardtii
following an exposition to Ce(NO3)3 or different types of CeO2 NPs (size, coating) using RNASequencing and flow cytometry. Biological effects observed in the algae were related to
bioaccumulation and speciation of the Ce. For a same total concentration of Ce (0.5 µM), the
three types of CeO2 NPs that were used (uncoated, citrate or poly-acrylic acid coated) induced a
Ce internalisation rate by algae similar or higher compared to Ce(NO3)3. Nonetheless, the NPs did
not induce the same alteration of the gene transcription, intracellular oxidative stress or
membrane permeability decreases that were observed in algae exposed to Ce(NO3)3 at the same
total concentration. The influence of the physicochemical properties of the NPs on the Ce
speciation and the importance of the free Ce as the major bioavailable fraction for C. reinhardtii
will be discussed.
O12 – Agil Azimzada
Characterization of silver nanoparticles in wastewater effluents and their interaction with
Chlamydomonas reinhardtii
As a result of the burgeoning nanotechnology industry, the number of uses of engineered silver
nanoparticles (Ag NPs) in consumer products has risen significantly in recent years. Despite their
utility as anti-bacterial agents, the ‘nano-scale’ properties of these nanoparticles also raise
potential exo-toxicological implications when they end up in the environment. Wastewater
effluents represent one of the main routes through which Ag NPs can reach an aquatic
environment, such as lakes and rivers, where they may potentially interact with the aquatic life.
In wastewaters, Ag NPs may undergo different chemical and physical transformations, which may
alter the potential toxicity of these NPs towards aquatic organisms. The main objectives of our
study are to characterize the Ag NPs in wastewater effluents and then assess their interactions
with a model organism, the green alga Chlamydomonas reinhardtii. In this presentation, results
will be shown which address our mass balances for the Ag NPs; characterize the dissolution and
aggregation behavior of the NPs for different types of media and assess the bioavailability and
uptake of Ag NPs by C. reinhardtii.
O13 – Trevor Théoret
Fate of silver nanoparticles in wastewater and biosolids using enhanced darkfield microscopy
and hyperspectral analysis
Nanomaterials are a class of emerging and increasingly produced contaminants that are present
in increasing concentrations. In complex environmental media, their detection is often
complicated by interferences from environmental matrices. The objective of this work was to
follow the fate of silver nanoparticles in the wastewaters using enhanced darkfield microscopy
(EDM) and single particle inductively coupled plasma-mass spectrometry (SP-ICP-MS). When
coupled with a pixel by pixel analysis, EDM can be used to screen for the presence of
nanoparticles, and to locate, identify, and follow their fate in situ. Transformation kinetics of
several different silver nanoparticles (40, 80 and 100 nm) with different coatings (citrate and
polyvinylpyrrolidone) were analysed in complex media (waste water, biosolids). Results
demonstrated that when spiked into complex systems containing natural organic matter, the
nanoparticles were rapidly transformed (over a period of 2 hours), as shown by a shift in the
wavelength attributed to their plasmonic resonance (450 to 570 nm) leading to a decrease in
signal intensity of 95%. Based upon complementary results obtained by dynamic light scattering
(DLS) and SP-ICP-MS, it was possible to attribute the changes not to particle aggregation or
dissolution as much as a change in the nature of the particles due to the adsorption of organic
matter on their surface. This presentation will show that the properties of the nanoparticles in
complex systems are very different from those in simple systems.
O14 – Jonathan Martin
Biomarker induction and silver accumulation in fish chronically exposed to silver nanoparticles
in a lake ecosystem
Nanomaterials are becoming increasingly popular in consumer products due to their unique
physico-chemical properties. Silver nanoparticles are found in a wide range of food packaging
materials, textiles, household appliances, cosmetics, and medical devices for its antibacterial
properties. As a consequence of increased use, there are concerns that silver nanoparticles are
entering waterways from municipal sewage systems in low (ppb) concentrations. The risks of low
concentrations of silver nanoparticles to aquatic ecosystems and the actual mechanisms of
toxicity in fish are largely unknown. The goal of this research was to determine in low
concentrations of silver nanoparticles added to Lake 222 at the Experimental Lakes Area induced
biomarker responses in natural populations of yellow perch (Perca flavescens) and northern pike
(Esox lucius). Silver nanoparticles were added to Lake 222 continuously for 30 weeks over two
consecutive summers from an onshore point source. Concentrations of silver in the lake were,
on average, <10 ppb by the end of the dosing regime each year. Fish were sacrificed during dosing
and gill, liver, and muscle tissue were collected for measurements of biomarkers and oxidative
stress responses, including glutathione, lipid peroxidation, metallothionein, and heat shock
proteins (biochemical responses and mRNA expression). Silver accumulation increased in the
liver, gill, and kidney of fish and concentrations in E. lucius were significantly higher than in P.
flavescens, which may be evidence of biomagnification. Overall, the results of this research help
elucidate the long-term effects on natural fish populations of low concentrations of silver
nanoparticles added to freshwater systems.
O15 – Louise-Emmanuelle Paris
Metal contamination assessment in rivers improved by biomonitoring using biofilms
Our study has been carried out in the Nunavik-Nickel mining area, in northern Ontario, Canada.
Nunavik’s bedrock is very rich in metals, namely nickel and copper, and the mining industry is
rapidly developing in this area. Despite governmental regulations for environmental protection,
metallic contamination is likely to occur and aquatic ecosystems are particularly at risk.
Nowadays the main method to monitor this contamination is done by measuring the surface
water metal concentration. This method will mainly reveal the current metal concentrations, but
may not reflect the chronic exposure of living organisms, especially in the case of small streams
where there are large variations in run-off inputs and flow regime. This is why we considered
using the metal content in biofilms as an indicator of metal exposure. Biofilms consist of the
natural communities (algae, bacteria and fungi) living on river bed substrates. In this context, we
are looking for a relationship between biofilm metal content and the free metal concentration in
surface water. A previous study already investigated this relationship in a region of southern
Québec. A significant correlation was observed for copper, zinc, cadmium, and lead. The goal of
this project is to compare the relationship between free metal concentration and biofilm metal
concentrations obtained in a northern environment with these existing data to evaluate the
consistency and reliability of biofilm metal content as a proxy for metal bioavailability. Ultimately,
we want to use biofilms to develop a multimetric index of metallic contamination.
O16 – Melissa Khadra
Effects of glyphosate on periphytic biofilms: a microcosm study
Glyphosate, the active ingredient in Roundup®, is currently the most widely used herbicide in the
world. Glyphosate is a broad-spectrum, non-selective systemic herbicide. The principal mode of
action of glyphosate is the inhibition of the synthesis of the 5-enolpyruvylshikimate-3-phosphate
synthase (EPSPS), an enzyme involved in the biosynthesis of essential aromatic amino acids
phenylalanine, tyrosine and tryptophan. Due to its short half-life, glyphosate is rapidly degraded
to aminomethylphosphonic acid (AMPA), which can alter the biosynthesis of chlorophyll.
Glyphosate and AMPA can therefore alter freshwater foodwebs and fish stocks by affecting
periphytic biofilms when leached into lakes and rivers. Microcosm experiments were conducted
to assess the impact of glyphosate on periphytic biofilms. Articifial substrates colonized by
periphyton were exposed to 4 different initial concentrations of glyphosate (0 ug/L, 6 ug/L, 65
ug/L and 600 ug/L) over a period of 7 days. The degradation of glyphosate to AMPA over time
was assessed. Temporal changes in the concentrations of essential aromatic amino acids were
also monitored. The concentration of chlorophyll a was determined at 0, 3 and 7 days after the
addition of glyphosate. Our results show that AMPA was only detected in the microcosms where
the initial concentration of glyphosate was 600 ug/L. An increase in phenylalanine, tyrosine and
tryptophan concentrations was observed after 7 days for all treatments. Chlorophyll a content
varied considerably between microcosms and did not show an unequivocal decline over time.
Based on these preliminary results, we cannot detect any substantially adverse effect of
glyphosate on the metabolism of periphytic biofilms.
O17 – Elizabeth Ashby
Accumulation of rare earth elements onto naturally occurring biofilms downstream of acid
mine drainage field sites.
Rare earth elements (REEs) are an integral component within an increasing number of advanced
materials, including superconductors, fuel cells and solar panels. Historically, REEs were thought
to pose little environmental hazard as a result of their low natural abundance and solubility.
Recently, REE exposure levels in acid mine drainage environments downstream of metal and coal
mines have been identified as 5-1,500 times background water levels (31 ug/L to 3,091 ug/L sum
of REEs). Within acidic mine drainage, REE are initially released as free ions or as soluble sulphate
complexes, but precipitate readily as the pH increases, resulting in solid phase enrichment of
REEs in organic and inorganic secondary minerals and colloids. This study compares co existing
water chemistry, biofilm chemistry and microbial 16sDNA samples from four different sites
affected by acidic mine drainage to better understand REE interactions with minerals and organic
matter under different pH conditions.
Samples were collected downstream from four sites affected by acidic mine drainage. The pH of
samples ranges from 2.63 to 7.31. Lower pH values are associated with greater aqueous REE
concentrations; higher pH values are associated with greater biofilm REE concentrations. The
total dry weight of biofilm REEs measured two to five orders of magnitudes higher than dissolved
co-existing water. At pH < 5, preliminary results indicate sorption to iron oxides is not observed,
rather abiotic precipitation and sorption to manganese oxides are the primary sorption
mechanisms. Results from microbial 16sDNA indicate that REE adsorption is not species specific.
O18 – Weibin Chen
Effect of natural organic matter properties on Pb, Cd, and Zn binding
Natural Organic Matter (NOM)is a complex molecule with diverse ligands that regulates metal
speciation and toxicity. This study aims to determine whether and how Pb, Cd, and Zn binding
property (i.e. affinity and capacity) is affected by NOM properties. NOM samples were collected
from autochthonous to allochthonous sources. The NOM properties were characterized by
different types of measurement, including fluorescence, absorbance, acidity and thiol. Pb, Cd,
and Zn binding experiements were performed over a wide analytical window (i.e. p[MT] = -8.5 to
-4) under controlled conditions (i.e. pH = 8.0, l = 0.1M KNO3, dissolved organic carbon = 10 mg L1). The concentration of free Pb2+, Cd2+ an Zn2+ ion was determined by Absence of Gradient and
Nernstian Equilibrium Stripping (AGNES) for constructing binding isotherm. The Fully Optimized
Continuous Spectrum (FOCUS) method was employed to derive metal binding affinity spectrum
(i.e. affinity vs. capacity).
Generally, allochthonous NOM with more aromatic structures and color moieties, and higher
molecular weight showed higher metal binding capacity than autochthonous NOM. This trend is
more pronounced for PB than for Cd and Zn. The PB2+ concentration varied by up to about 3 log
unit between NOM samples, whereas the Cd2+ and Zn2+ concentrations varied by only 1-2 log
unit. Therefore, environmental models used to predict metal speciation and toxicity should
consider NOM properties, such as aromatic structure.
O19 – Caroline Doose
Thorium uptake and effects on primary producers: from the laboratory to the field
The development of new technologies has significantly increased the demand for rare earth
elements. Canada has a strong mining potential notably in rare elements and uranium, for which
the country is the second largest producer. Thorium is a natural radioactive metal often
associated with the waste of both of these mining activities. It is also found in phosphate
fertilizers. These activities cause the release of thorium in the environment and potential
freshwater contamination. However, environmental risks associated to thorium are still relatively
unknown especially in aquatic ecosystems. Unlike many other elements, the links between its
speciation in freshwater and its bioaccumulation by aquatic organisms remain unknown. The first
objective of this work is to determine the impact of natural ligands on thorium uptake by primary
producers. A series of short term uptake experiments (<1h) will be conducted with the alga
Chlamydomonas reinhardtii to determine the thorium internalisation fluxes. Environmentally
relevant ligands will be added to exposure media to verify the applicability of the Biotic Ligand
Model (BLM). A second objective will be to determine the subcellular distribution of thorium in
the same alga. Because certain fractions are more easily assimilated by predators, thorium
repartition inside the cells allows estimating its trophic transfer potential. Third we will examine
benthic microorganisms’ community (periphyton) responses to thorium. Recent work on biofilms
has shown its potential use as a bioindicator of freshwater contamination. This work will
contribute to improve risk assessment of mining activities that release thorium in aquatic
ecosystems.
O20 – Biance Pereira
Nickel speciation in marine samples using ion exchange technique: relation to toxicity in
embryonic life
Nickel (Ni) is important in marine environments due to increased prevalence of industrial
effluents. However, the potential protective role of dissolved organic carbon (DOC) against
Ni2+toxicity is not yet well established. Various DOC samples have been collected from multiple
sites along the eastern coast of the United States (Connecticut and Rhode Island). Nickel toxicity
has been assessed in these samples using sensitive early life stage (embryo) testing. Using these
tests the total dissolved nickel concentrations effecting 50% of the organisms (EC 50) will be
determined. Speciation using ion exchange techniques (IET) will be used for a link between Ni
chemistry and toxicity. IET consists of an equilibrated cation-exchange resin with the water
samples where the concentration of adsorbed free metal ion is proportional to the Ni free ion
solution. Variable including reaction time and minimum detectable Ni will be optimized to
develop a salt water specific batch method. IET will be used to measure metal free ion at the
measured EC50 level. The hypothesis is that the concentration of free Ni should be constant at
the EC50 even though based on total Ni effects concentrations vary. Results regarding method
development ant its applications to marine samples will be presented and compared to metal
toxicology in DOC samples.
O21 – Jonathan Ford
Impact of cation competition and temperature on aquatic toxicity of thulium to Hyalella Azteca
Rare Earth Elements (REEs) are a group pf metals with unique physical and chemical properties.
There is an increase in demand for REEs, but very little research has been completed regarding
the environmental effects of these metals. A preliminary study on the aquatic toxicity of 63
elements and compounds including REEs. Borgmann et al. (2005) showed that thulium (Tm) was
the most toxic REE, with a measured LC50 of 0.01 μg/L. the objective of my research is to develop
an improved understanding of aquatic toxicity of temperature and cation competition (Ca2+,
Mg2+, and Na+). Acute toxicity tests will be conducted following the standard method provided
by Environment Canada (EPS 1/RM/33). The medium will be a standard of reconstituted water
with a hardness of 62 mg CaCO3/L and the endpoint will be mortality after 96 hours. Tests will be
conducted using a range of temperatures (e.g. 21, 15, 9), and increased amounts of Ca, Mg, Na.
It is hypothesized that lower temperatures will result in a lower toxicity (Chapman 2015), while
cations will provide a protective effect on the organisms. This study will improve our
understanding of Rare Earth Elements and the potential impact on aquatic environments. This
research is supported by Environment Canada and NSERC with contributions of Avalon Rare
Metals Inc.
O22 – Giselle Cameron
Natural organic matter characterization and lead speciation as indicators of potential lead
bioavailability in aquatic environments
Trace metals play an important role in aquatic systems. While some trace metals are essential
for aquatic life, other metals may cause toxicity to biota if present in high enough concentrations.
Lead is one such non-essential metal, and can be found in a variety of different forms in aquatic
environments. These different forms, or species, potentially display different mechanisms and
levels of toxicity. This makes speciation, and the factors that influence it, important to consider
when addressing toxicity, as water chemistry varies greatly with location. Organic content is one
parameter affecting speciation and therefore toxicity, making it an important factor to address.
This project aims to characterize various sources of natural organic matter (NOM) and define lead
speciation in aquatic environments, using both artificial and natural ligands. NOM from different
locations will be analysed to determine if lead binding characteristics are source-dependent.
Flow-through and static analysis have been employed with a commercially available solid-state
ion-selective electrode (ISE) and constructed liquid-membrane ISE respectively in order to
determine lead speciation. Fluorescence Spectroscopy, absorbance spectroscopy, total carbon
(TOC), dissolved carbon (DOC), organic nitrogen, chromium-reducible sulfide, thiol assays and
acid-base titrations will be utilized to describe various NOM sources and to explain any sourcedependent lead binding. NOM sources include Suwannee River, Nordic Reservoir, Amazon Rio
Negro, Luther Marsh and Bannister Lake. This project aims to provide valuable information to
help improve existing predictive models, such as the biotic ligand model (BLM), which allow for
site-specific water quality guidelines.
O23 – Gbatchin Kochoni
The role of trace elements in the uptake and toxicity of copper
The Biotic Ligand Model allows predicting metal uptake and toxicity based on metal speciation
and the presence of competitive ions. Many research studies are conducted in order to further
improve this model, and to apply it in aquatic ecosystems management. Despite its increasing
popularity, its applicability in some conditions remains unclear. For example, what is the role of
metal nutrition on trace metal toxicity? Our research works is based in this perspective; and aim
to better understand the mechanisms that govern the uptake and toxicity of copper by using a
freshwater alga, Chlamydomonas reinhardtii, as a biological model. Recent studies on trace
elements (Cu, Co, Zn, Mn, Fe) have revealed, under certain exposure conditions, an unexpected
toxic response of Cu2+ at concentrations as low as 10-11 M. We hypothesize that other
micronutrients (Zn, Fe, Co, Mn) play an important role in copper accumulation and toxicity.
Preliminary experiments indeed suggest that iron could strongly modulate the toxicity of copper.
In subsequent experiments, we plan to explore the intracellular fate of copper by using stable
isotopes to follow “new” incoming metal in different cell fractions. We hope that our approach
will allow us to better understand the importance of trace metal nutrition in copper cell
metabolism. The environmental implications of our results may imply including metal nutrition
in toxicity prediction models.
O24 – Matt Boag
The immobilization of metals in peatlands: characterizing the interactions between metals and
organic matter
Organic soils, especially peatlands, cover large areas of Canada's north and are vital to
geochemical cycling. Organic matter in these soils can be described as heterogenous mixtures of
chemical moieties that control the soil response to chemical inputs. In northern environments
impacted by mining, organic systems play an important role in complexing and buffering both
essential and potentially toxic metal species. There is also evidence that remobilization of metals
takes place after periods of freezing and thawing, which can be expected to cause seasonally
elevated concentrations of metals in water discharging from peatland environments.
Our project investigates the physical changes that occur in the pore water of peat soil after a
period of freezing and thawing. Our interests lie in studying how these physical changes attribute
to metal re-localization in different size fractions of our samples as well as characterizing the
chemical interactions between metals and organic matter. To fully understand these interactions,
it is vital to identify the relationships between different size classes of the organic matter, the
concentration distribution of dissolved organic matter, and the composition of functional groups
with respect to Cu complexation.
We are separating organic matter into size fractions using ultrafiltration, conducting acid-base
titrations to characterize the functional group composition of different size fractions, and
applying fluorescence spectroscopy. Fluorescence spectroscopy appears to offer the most
promising means for rapid assays of characteristic humic and fulvic-like chemical moieties in
dissolved organic matter. These analyses will also be performed on chemically extracted humic
and fulvic acids to compare the differences between contrasting approaches to studying organic
matter. We are also using Cu-ISE techniques to help assess the solution chemistry of Cu in the
presence of dissolved organic matter.
Our studies offer critical information that is currently lacking about factors controlling the
mobilization of metals from wetland soils to downstream environments, which is particularly
important given climate change impacts predicted for Canada's north.
O25 – Elissa Dow
The interaction of dissolved organic matter with nickel in marine waters
Nickel is a metal with many industrial applications, however Canadian marine regulations for this
metal are potentially under-protective, as not all water quality parameters are taken into
account. Over time, anthropogenic nickel is introduced into water systems where problems can
arise. Aquatic plants and animals are susceptible to toxic effects if concentrations of nickel are
too high. Toxicity levels are proportional to the concentration of the free metal ion, Ni 2+, bound
to the biotic ligand, a site of action on an organism.
In fresh water, dissolved organic matter (DOM) has been shown to form complexes with nickel
and to lower the concentration of Ni2+ ions in the water, thus reducing the bioavailability and
toxicity of the metal toward aquatic species. However, there is much less data on nickel
complexation for marine water. Water chemistry varies from site to site, meaning that one
location may have more protective effects than another. This project observes nickel’s
interactions with DOM from a variety of sources. The two major techniques used are
fluorescence spectrophotometry and a novel, in-house ion-selective electrode (ISE). Ultimately,
this research aims to contribute information toward establishing appropriate water quality
guidelines.
O26 – Sohidul Islam
Mineralization of dissolved organic matter in the Hudson Bay system (Canada)
Dissolved Organic Matter (DOM) largely influences the global carbon cycle. As one of the largest
inland sea in the world, Hudson Bay receives large amount of DOM from more than 42 rivers.
Discharge from the main rivers including the Nelson River emptying into Hudson Bay has been
regulated mainly for hydroelectric generation. The timing, duration, volume and location of
freshwater loading to Hudson Bay have a major influence on the properties and processes of the
marine waters and the dynamics of sea ice, which in turn strongly influence primary productivity,
carbon and contaminant cycling in the Bay. Variability of DOM concentration and composition
could be caused by sea ice melting, light penetration and different regional variation of river
influx into Hudson Bay. Few studies showed an important impact of transported DOM from the
surrounding river run off into the marine ecosystem. But, little is known about DOM degradation
process in freshwater-marine coupling in Hudson Bay. This project will investigate photo and
microbial degradation of DOM in Hudson Bay. Photochemical mineralization rates of DOM will
be estimated by using absorption and excitation emission spectroscopy. Microbial removal of
DOM will be quantified applying the river microbial communities to estuarine and Bay water. In
the large scale arctic and sub-arctic regions contain a big amount of organic carbon that might
effect in regional warming. The Hudson Bay is special since it receives larger amount of organic
matter relative to Arctic Ocean hat may not only effect in regional climate but also on the biota.
O27 – Vaughn Mangal
Dissolved organic matter (DOM) and the role of molecular weight influencing mercury
bioavailability
Dissolved organic matter (DOM) is classified as small (<0.45μm) hydrocarbon structures in
aquatic ecosystems deriving from a variety of sources such as terrestrial inputs and biological
activities. DOM functions as a nutrient source for many microbial communities, acts as an
ultraviolet (UV) blanket and serves as one of the main organic ligands to many divalent metals,
such as mercury (Hg). While it is understood that DOM binds to Hg, variables such as DOM
concentration, composition and molecular weights (MW) influence the overall bioavailability of
the resulting Hg-DOM complex. The proposed presentation emphasizes on the role that different
MW fractions of phytoplankton-derived DOM serves on Hg bioavailability. Using asymmetrical
flow field-flow fractionation (AF4) coupled to a UV-Visible Diode Array Detector, MW fractions of
DOM were separated and quantified while preserving the natural state of the DOM. To assess
the impact of DOM MW fractions on Hg uptake in aerobic environments, an Escherichia coli
bioreporter containing a lux plasmid was exposed to 250 pM of Hg at fixed carbon
concentrations. Results indicate bulk samples yielded an overall decrease relative to Hg with no
DOM present; however, phytoplankton-derived DOM between 350-1000 Da consistently
enhanced uptake of Hg. Furthermore, larger MW DOM (>1200Da) reduced the uptake of Hg
relative to both bulk solutions and lower MW DOM fractions. The present findings suggest that
MWs of DOM ligands bound to Hg impact the overall speciation, and ultimately the bioavailability
of Hg-DOM complexes under aerobic settings.
O28 – Justine-Anne Rowell
Role of natural organic matter on rare earth elements speciation and bioavailability with
Chlamydomonas reinhardtii
As technological interest for rare earth elements (REE) is growing, it is becoming more important
to assess their potential environmental impact. Indeed, specific knowledge is required about the
behaviour of these metals in rivers and soils, more precisely with respect to the factors that
influence their speciation and bioavailability. Based upon models such as the Biotic Ligand Model
(BLM) that have been successful for predicting the effects of divalent metals, the complexation
of metal ions by natural organic matter is predicted to reduce the free ion concentration and
simultaneously decrease metal bioavailability for aquatic organisms. Nonetheless, recent studies
using simple organic ligands have shown that REE biouptake is higher than predicted. Thus, it
becomes extremely relevant to determine REE speciation in natural waters, especially in the
presence of natural organic matter, in order to predict their bioavailability. In this study, a
dynamic ion-exchange technique was used to determine free ion concentrations and in parallel,
biouptake experiments were performed to measure the internalization flux of REE in algae.
Samarium (Sm), an intermediate lanthanide, and the unicellular green alga Chlamydomonas
reinhardtii were employed, and results were compared with modelling efforts in order to better
understand the important factors leading to REE bioavailability.
O29 – Benjamin Stenzler
The role of dissolved organic matter molecular weight and chloride complexation on anaerobic
mercury bioavailabilty
Dissolved organic matter (DOM) and chloride are the dominant complexing agents influencing
mercury (Hg) speciation in the environment. However signal production for current Hg
bioreporters requires oxygen, namely for lux and gfp genes, resulting in a paucity of data in
anaerobic bioavailability of Hg species where it is methylated to toxic CH3Hg+. We developed and
optimized an anaerobic whole-cell mercury bioreporter using Escherichia coli 5α by transforming
a vector containing the gene fusion between the regulatory circuitry of the mer-operon and a
flavin mononucleotide-based fluorescent protein. The lower detection limits of the developed
bioreporter were 250 pM Hg(II) with an optimal sensitive range for speciation detection at 5nM
Hg(II). The proposed presentation emphasizes on the role that different molecular weight
fractions of phytoplankton-derived DOM and chloride complexes serves on Hg bioavailability
using the developed bioreporter. The DOM fractions were separated and quantified using
asymmetrical flow field-flow fractionation (AF4) coupled to a UV-Visible Diode Array Detector.
Preliminary results for anaerobic bioavailability of Hg complexed to algal extract fractions showed
decreased bioavailability with increasing molecular weights; this observation was dependent on
the algal species. Bioavailability of the HgCl42- species was higher than other inorganic Hg species
contrasting with aerobic exposures and providing a possible mechanism for greater Hg
methylation rates in saline environments. Indicating that anaerobic Hg bioavailability may have
dependency on present phytoplankton species while HgCl42- uptake.
O30 – Florent Risacher
Oil sands end pit lake redox biogeochemistry I: water cap physiochemical zonation
End-pit lakes (EPL) are being assessed as a wet reclamation strategy for fluid fine tailings (FFT) in
Alberta's oil sands. The first pilot EPL has been built to assess the viability of this strategy and its
study is therefore critical to future reclamation projects. This EPL contains ~ 30 m of FFT
deposited into a retired open-pit mine overlain by a ~ 10 m water cap. As FFT contains reduced
gaseous and aqueous chemical species such as CH4, Fe2+, H2S and NH4+, as well as organic carbon
and microbes, there is concern that their release may prevent the formation of a permanent oxic
water cap necessary for the establishment of macrofauna and algae. Furthermore, the
dewatering of FFT, more saline than the overlying water cap, releases heat. Thus, complex
physical and biogeochemical processes are likely to affect water cap oxygen status. As part of a
larger project that will characterize water cap redox biogeochemistry and oxygen consumption,
the objective of this field-based project is to characterize how water cap oxygen and other
physico-chemical parameters vary with depth and season. We surveyed the lake from early June
to mid-September at six sites on a weekly basis, characterizing water cap depth dependent
temperature, O2, pH, conductivity, salinity and redox (YSI 6820 V2-2). Physico-chemical profiles
for the first field season (June-September 2015) indicate thermal and O2 zonation within the
watercap and seasonal mixing of the water cap. These results and their implications for EPL
biogeochemical cycling will be presented.
O31 – Patrick Morris
Oil sands end pit lake redox biogeochemistry II: water cap geochemistry
Operators in the Alberta Oil Sands Region (AOSR) are pursuing development of wet reclamation
techniques for fluid line tailings (FFT) through the development of end pit lakes (EPL). As FFT
contain highly redox reactive compounds as well as viable microbial communities, there is a need
to establish the redox biogeochemical cycling within the water cap. The objective of my project
is to characterize the water cap geochemistry over depth dependant, seasonal and annual scales.
To date, physicochemical profiles and water samples for C, S, P, N, Fe redox species and
suspended solids were collected at three deep sites (>8m) and three shallow sites (<3m) weekly
from late May-August and once in October 2015 after fall turnover. Further sampling campaigns
are planned for winter 2016 under ice and for 2016-2017. Sampling depths were chosen based
on physicochemical profiles within the water cap to capture evident zonation and oxygen
gradients. Water cap oxygen zonation (approximate % saturation: 70% epilimnion, metalimnion,
step decreasing gradient from these preliminary geochemical results include lower
concentrations of sulfate and nitrate and correspondingly increased concentrations of sulfide and
ammonium in the matlimnion relative to the epilimnion and hypolimnion consistent with focused
microbial redox biogeochemical cycling within this interfacial region. DOC and methane
concentrations show contrasting trends with DOC higher at shallower depths while methane
decreases sharply from the hypolimnion to the epilimnion.
O32 – Daniel Arriaga
Oil sands end pit lake redox biogeochemistry III: water cap oxygen consumption
The first pilot scale end pit lake (EPL) is now being assessed in Canada’s oil sands region, using
water capped tailings technology (WCTT) for fluid fine tailings (FFT) management. The key to the
viability of EPL as a reclamation strategy will be the evolution of the water chemistry such that
the EPL is capable of supporting aquatic biota. The objectives of this field based study are to: 1)
determine in situ rates of oxygen consumption at multiple sites and depths over the ice free
season, and 2) identify the key redox biogeochemical processes involved. Oxygen consumption
rates (OCR) using a customized sealed bottle with an oxygen sensor directly embedded through
an air tight port, were determined in situ at 6 sites and multiple depths associated with
physicochemical zonation from June to September 2015. Samples were collected at the start of
the in situ experiments and at the end for all major redox couples (i.e., H2S, SO42-, Fe2+, Fe3+, NH4+,
NO2-, NO3-) and organic carbon (CH4, CH2O) to identify the processes driving oxygen consumption
within the water cap. Depth dependent OCR ranged between 1 and 18 μM/L/hr, which are an
order of magnitude higher those reported for unimpacted freshwater systems (e.g. 0.15 - 0.3
μM/L/hr, Shapiro, 1960; Townsend, 1999; Rippery and McSorley, 2009). While O2 saturation was
always highest in the epilimnion (65-70%), the highest OCR occurred in the metalimnion
associated with steep O2 gradients. These results and their implications for the development of
this EPL will be discussed.
O33 – Marie Sereneo
The sublethal effects of diluted bitumen in rainbow trout (Oncorhynchus mykiss)
An increased demand for Canadian diluted bitumen (dilbit) has resulted in new pipeline proposals
for transportation to coastal ports for shipment to foreign markets. Access Western Blend (AWB)
and Cold Lake Blend (CLB) were identified as the highest-volume dilbit products currently shipped
in Canada, each with varying physical properties and chemical compositions. In conventional
crude oils, toxicity has been attributed to 3 to 5 ringed alkylated polycyclic aromatic
hydrocarbons (PAHs). Though dilbit is similar to conventional crude oils in physical properties,
volatility of these PAHs in dilbit during oil spills scenarios causes changes to its environmental
fate and behaviour. This study characterizes a set of dilbit-responsive biomarkers in rainbow
trout (Oncorhynchus mykiss) embryos to establish salmonid sensitivity for populations at risk to
dilbit spills caused by transportation of pipeline failures. Embryos were exposed for 24 days to
varying concentrations of chemically-enhanced water accommodated fractions of AWB and CLB
dilbits. Toxicity was determined by measuring mortality rate as well as the development of blue
sac disease (BSD) in embryos at the end of the 24-day exposure. Furthermore, toxicity-related
biomarkers were assessed through relative mRNA levels of genes associated with phase I (cyp1a),
phase II (hsp70, gst, gpx, nfe2, gsr, sod, cat), xenobiotic metabolism (ahr2, arnt), and mutation
response (p53). This is the first study on the physiological effects of dilbit exposure in native
Canadian fish species that may provide a baseline for other economically important salmonids
with carrying life strategies and environmental sensitivities.
O34 – Kawina Robichaud
Large-scale engine oil contamination – could local organic materials be an answer?
The contamination of soils by petroleum-hydrocarbons (PHC) is a widespread concern across the
globe. In Québec, most soil clean-up facilities manage lighter hydrocarbons such as gasoline or
diesel. Heavier petroleum products like engine oil are more challenging and time-consuming to
degrade. Consequently, few facilities have the regulatory permits to accept such soils and many
are looking for effective field-scale techniques.
Nutrients like nitrogen are known to promote PHC-degradation by soil microbes. Hence, low-cost
inorganic fertilizers are commonly used amendments. Additionally, physicochemical
characteristics and organic matter can stimulate the soils’ microbial community. Therefore, we
hypothesized that the addition of organic amendments containing nutrients and alternative
carbon sources would yield superior degradation results than fertilizer alone.
From June to November 2015, a research project was conducted in collaboration with a soil
clean-up facility to assess the efficiency of three organic amendments plus their usual inorganic
fertilizer treatment. Twelve 0.76m3 concrete cylinders equipped with a pulled air system were
randomly divided to 4 treatments (control, horse manure, ramial-chipped-wood and brewer’s
spent grain). Temperature, O2, CO2, moisture, nutrients, organic matter and PHC were monitored
throughout. In November, soils were assessed for their microbial activity and functional diversity
with Ecoplates.
The best PHC-degradation was attained with manure (5000±100mg/kg = 77± 2.6% decrease).
Regulation-wise, all treatments but the spent grain reached the C criteria (industrial use: 3500
mg/kg). Although the spent grain performed the least in terms of degradation, it showed the
steadiest microbial activity into November. We are still investigating the mechanisms at play.
3MT
T1 - Carolina Dahmer
The role of hydroxypropyl-β-cyclodextrin in DDT remediation at Point Pelee National Park
Point Pelee National Park (PPNP) is heavily contaminated with dichlorodiphenyltrichloroethane
(DDT). This pesticide was widely used for mosquito and pest control in the Park from 1948 to
1967. Since the 1990’s when the presence of DDT was discovered in tissue samples from the
Park’s wildlife, DDT has become a major concern for Parks Canada personnel. The focus has been
on remediation techniques that will not interfere with the ecological integrity of the Park. These
techniques have included phytoextraction of DDT by crop species, Curcubita pepo, and native
plant species, including Panicum virgatum and Schizachyrium scoparim, as well as the use of
hydroxypropyl-β-cyclodextrin (HPβCD) to increase DDT solubility and microbial degradation.
HPβCD is not commonly used in remediation, however early experimentation by researchers
from McMaster University presented optimistic results. They reported removal of up to 90% DDT
from surface soils at the experimental site, and suggested that the decrease in DDT concentration
was due to enhance in-situ biological degradation. A re-examination of their data suggests that
HP􀈻CD could actually be mobilizing DDT into the groundwater, rather than enhancing its
degradation. Moreover, there is no solid evidence that microbial degradation of DDT increased
due to HPβCD application. Although both remediation methods have been tested at pilot-scale
in PPNP, a possible combined approach is yet to be investigated. The present study focuses on
understanding the true role of HPβCD in DDT remediation and the possibility of combining its use
with phytoextraction.
T2 – Elizabeth Ashby
Accumulation of rare earth elements onto naturally occurring biofilms downstream of acid
mine drainage field sites.
Rare earth elements (REEs) are an integral component within an increasing number of advanced
materials, including superconductors, fuel cells and solar panels. Historically, REEs were thought
to pose little environmental hazard as a result of their low natural abundance and solubility.
Recently, REE exposure levels in acid mine drainage environments downstream of metal and coal
mines have been identified as 5-1,500 times background water levels (31 ug/L to 3,091 ug/L sum
of REEs). Within acidic mine drainage, REE are initially released as free ions or as soluble sulphate
complexes, but precipitate readily as the pH increases, resulting in solid phase enrichment of
REEs in organic and inorganic secondary minerals and colloids. This study compares co existing
water chemistry, biofilm chemistry and microbial 16sDNA samples from four different sites
affected by acidic mine drainage to better understand REE interactions with minerals and organic
matter under different pH conditions.
Samples were collected downstream from four sites affected by acidic mine drainage. The pH of
samples ranges from 2.63 to 7.31. Lower pH values are associated with greater aqueous REE
concentrations; higher pH values are associated with greater biofilm REE concentrations. The
total dry weight of biofilm REEs measured two to five orders of magnitudes higher than dissolved
co-existing water. At pH < 5, preliminary results indicate sorption to iron oxides is not observed,
rather abiotic precipitation and sorption to manganese oxides are the primary sorption
mechanisms. Results from microbial 16sDNA indicate
that REE adsorption is not species specific.
T3 – Justin Whitaker
Investigating the overexpression of urease apoprotein in Sporosarcina ureae for increased
ureolytic activity
During an earthquake, soil bases undergo dynamic shaking. This can lead to a process known as
liquefaction. Liquefied-induced events are detrimental and result in indescribable costs in
building damages, losses of human life and massive changes in geographic stability. Some studies
postulate that the earth is in the middle of a magnitude 8 or greater earthquake cycle, with the
greatest event may yet to occur. Current grouting techniques to help mitigate the potential
damages are often costly, permanent and toxic. The goal of the project is to remedy the need for
an environmentally sound and economically viable application for improving the strength
parameters of sandy soils; most especially in earthquake and
landslide prone zones.
A urease positive bacterium, Sporosarinca ureae in the presence of urea, a calcium salt and a
saturated environment is proposed to work effectively under alkaline conditions (pH > 8) and
room temperature to produce a binding matrix of calcium carbonate in treated (175.8 +/25.4kPa) versus untreated (19.4 +/-0.8kPa) soils. Efforts are currently being applied to optimize
microbial cementation via recombinant methodology (i.e. urease overexpression, thiol
substitutions, etc).
This multidisciplinary study seeks to engage the general public with an earth-friendly solution, as
one of the broad spectrum of techniques being developed around the world, to combat a
devastating, worldwide phenomenon soil liquefaction. In discussing the project, it is hoped that
an increased appreciation will be garnered among communities of the need for alternative, ecofocused pathways which look to solve the vast array of global concerns facing the world today.
T4 – Tash-Lynn Colson
Toxicity of PCBs and PANA to juvenile snapping turtles
Polychlorinated biphenyls (PCBs) as well as substituted phenylamines antioxidant (SPAs) are two
groups of chemicals, which have been used in multiple industrial processes. PCBs were primarily
used in the 20th century in electrical transformers due to their stability, and dielectric and fire
resistant properties. Despite the PCB production ban in North America in 1977, they are
ubiquitously found in the environment and in wildlife as they are highly lipophilic and recalcitrant.
Previous studies have shown PCBs to be neurotoxic, genotoxic, developmentally toxic, and they
have been classified as endocrine disruptors. In contrast, SPAs, specifically N-phenyl-1naphthylamine (PANA), has received very little attention despite their current use in lubricating
oil and rubber manufacturing as an antioxidant. There is a research gap regarding the effects of
PANA and PCBs in reptiles; therefore, juvenile snapping turtle (Chelydra serpentina) was studied
due to its importance as an environmental indicator.
Three chronic exposures were performed in C. serpentina: 1) Used food spiked with 500 ng/g
A1254 to model bioaccumulation and depuration of PCBs in the liver. Turtles were fed spiked
food for 30 days followed by clean food for 51 days; 2 and 3) used A1254 and PANA spiked food
to determine liver toxicity and accumulation in C. serpentina. Toxicity was assessed by comparing
the expression of oxidative stress and metabolic genes. Results have shown a dose dependant
increase of PCB concentrations in turtle livers. Gene expression analysis shows an increase in
cyp1a expression in liver from turtles exposed to either A1254 or PANA, indicating its
involvement in metabolism.
POSTER
P1 - Isaiah Farahbakhsh
Background environmental assessment in Webequie First Nation, Northern Ontario
The peat soils of the James Bay Lowlands are situated atop glacial tills, which overlie the bedrock
of the Canadian Shield, including the metal-rich formations of the area dubbed the “Ring of Fire”.
The recent discovery of chromite and other valuable metals has made this area highly sought
after and the resource development to follow will likely cause significant environmental
consequences. The Webequie First Nation (WFN) is situated on Eastwood Island in Winisk Lake
and is the closest community to the proposed Ring of Fire mining developments. As there has not
been any previous baseline testing in this area, a collaboration between researchers from the
University of Guelph and WFN was initiated to establish baseline values. Standard field and
laboratory methods were used to test the pH, alkalinity, dissolved oxygen, conductivity, and
inorganic elements; lignin and stable isotopes of N and C were also assessed. The importance of
sediment monitoring can be viewed in light of the dissolution, precipitation and adsorption
reactions. Laboratory analysis shows the water in the Winisk River near Webequie was low in
dissolved solids and alkalinity. Some metals of concern were detected (chromium, lead, nickel
and zinc), but their concentration was below the recommended limits. The water was found to
be soft and poorly buffered which could imply a fragility to changes in water chemistry. Analyses
of the organic geochemistry (lignin, stable isotopes of N and C) revealed linkages between
terrestrial and riverine organic matter, with an anomaly at the southern boundary of the territory
indicating a potential disturbance.
P2 - Mitchell Brown, Trevor Reid, Gordon Wong
Design of a portable desulphurization unit for the disaster assistance response team (DART)
The Disaster Assistance Response Team (DART) is Canada’s multidisciplinary organization
designed to deploy on short notice, anywhere in the world, in response to situations ranging from
natural disasters to complex humanitarian emergencies. DART relies on a truck fleet
manufactured in North America and designed to run on ultra-low sulfur diesel (<15ppm) in
accordance with Environment Canada that regulates the sulphur content in diesel fuels in an
attempt to diminish its negative impact on the environment. Unfortunately, where DART deploys,
there are large fluctuations in the sulphur levels (15-5000 ppm) of diesel fuel supplies. While the
DART truck engines are able to run oh high sulphur diesel it has been shown that detrimental
effects occur, to the engine and related duel supply and emission systems, threatening operation
capability and longevity of the DART truck fleet. As a possible solution to this problem, while
reducing environmental pollution, the design of a portable diesel desulphurization unit is being
developed that can be utilized by DART during deployment overseas, the design achieves a
decrease of the overall sulphur content in the diesel to acceptable Canadian standards while
implementing proven technologies for reliability and strategies fro reducing waste.
P3 - Kevin Panthinather, Clarize Virtusio, Jaden Rook
Activated carbon treatment process for the remediation of perfluorinated alkyl substances
from contaminated groundwater
Perfluorinated alkyl substances (PFAS) were used widely since the mid-2th century for a variety
of commercial and industrial purposes. The use of PFAS in aqueous film forming foam (AFFF), a
firefighting agent used commercially and militarily, has resulted in PFAS contamination of the
aquifer at one particular Canadian airport. The two primary PFAS that will be examined in this
project will be perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). These two
PFAS are the most commonly found PFAS in the environment and will therefore be the focus of
this project. PFAS has particularly difficult to remove from the environment as a result of the
strong carbon-fluorine bond and for PFOS and PFOA, the long carbon chains. This project
examined the existing remediation techniques and a decision matrix process was used to predict
the most effective technique for the removal of PFAS at this site. Among the many remediation
techniques are: carepture by activated carbon, reverse osmosis filtration followed by UV
activated perfulfate oxidation, and sonochemical degradation. The decision matrix was used to
determine that capture by activated carbon would be the most viable option. Upon selection of
activated carbon as the method of choice, a process design was developed for the various
components of the remediation technique.
P4 - Daniel Grégoire, Danielle Prapavessis
A physiological role for Hg(II) during phototrophic growth
The bioaccumulation of toxic monomethylmercury is influenced by the redox reactions that
determine the mercury (Hg) substrate available for methylation. Hg(II) and Hg(0) are substrates
for monomethylmercury formation. Phototrophic microorganisms can reduce Hg(II) to Hg(0).
This reduction has been linked to a mixotrophic lifestyle, in which microbes gain energy
photosynthetically but acquire diverse carbon compounds for biosynthesis from the
environment. Photomixotrophs must maintain redox homeostasis to disperse excess reducing
power due to the accumulation of reduced enzyme cofactors. Here we exposed purple bacteria
growing in a bioreactor to Hg(II) and monitored Hg(0) concentrations. We show that phototrophs
use Hg(II) as an electron sink to maintain redox homeostasis. Hg(0) concentrations increased only
when bacteria grew phototrophically, and when bacterial enzyme cofactor ratios indicated the
presence of an intracellular redox imbalance. Under such conditions, bacterial growth rates
increased with increasing Hg(II) concentrations; when alternative electron sinks were added,
Hg(0) production decreased. We conclude that Hg can fulfil a physiological function in bacteria,
and that photomixotrophs can modify the availability of Hg to methylation sites. Given the
promising results obtained with purple bacteria, we have begun testing whether other
phototomixotrophs, namely the green alga Euglena gracilis, can reduce Hg(II) through similar
mechanisms and whether or not this support a detoxification strategy when cells are exposed to
sublehtal levels of Hg.
P5 - Galen Guo
Human gut microbiome transformation of mercury
Fish and fish predatory consumption provides nutrients, some of which are essential for brain
growth and development. Fishing and hunting are essential to First Nations communities not only
as food sources, but also in their traditional and holistic practices. However, methylmercury
(MeHg) bioaccumulation in fishes and fish predators; MeHg results from the activity of anaerobic
microbes. MeHg is an environmental toxicant that leads to long-lasting neurological and
developmental deficits in humans. Due to increasing anthropogenic activities, mercury (Hg) has
ben remobilized in the environment leading to increases in fish Hg concentration. As a result,
governmental agencies have strict regulation on daily intake, impacting fishing and hunting in
those communities. Epidemiological studies show great variation between different aboriginal
communities but also between individual within a community. Although, genotyping plays a role
in this variation, the gut microbiota of those individuals is likely to play an essential role in the
transformation of Hg. Mouse studies have suggested a possible link between the activity of gut
microbes and the excretion of mercury from the body. The objectives of this project are i) to test
whether gut microbiota can transform mercury in-situ and ii) whether diet can affect this activity.
P6 – Ria Saha
Role of diet in shaping up the human gut microflora and how it affects mercury metabolism
Recent research showing how dietary interventions substantially influences the potential
presence of widespread and stable bacterial core phylogroups in human colon has promoted
considerable attention. Because human gut can play a major role in host health, there is currently
some interest to observe how diet influences human gut microbial composition and how that
changes in diet affect the potential of the gut microflora to transform mercury. Mercury is toxic
to human life and one of the maor pathways f its exposure to humans is via food. Here we
investigate the response of gut microbes to changes in metalloid(s) availability and toxicity by
monitoring potential genes mer A (mer-operon) and HgcA and HgcB responsible mercury
methylation.
Method: The response of human fecal microbial communities are studied here from human fecal
samples (collected from 5 human individuals and pooled together) in an anaerobic batch cultures
art pH5.5-6 supplied with 4 different diets (balanced, high carbohydrate, high protein, and high
fat). Alteration in diet composition results in quantitative changes in the supply of substrates.
Analysis of samples will be performed using high throughput sequencing of the 16S rRNA genes
and the QIIME pipeline.
Furthermore, stable Hg isotopes will be added as tracers to trach Hg transformations during these
batch incubations, especially Hg methylation and demethylation.
P7 – Antoine Hnain for
Hydroponic uptake and speciation of arsenic in Equisetum fluviatile (water horsetail) and
Equisetum hyemale (rough horsetail)
Arsenic is a toxic metalloid that is found in ground and surface waters in Canada as a result of
mining activities. Horsetail plants (equisetum spp.) have been known to grow in areas with
elevated arsenic levels in soils and sediments and have also shown a high capacity for arsenic
uptake. To date, there have been no controlled experimental studies looking at As uptake in
Equisetum spp. In a hydroponic (soil free) system. Using Hoagland’s nutrient solution in a
hydroponic system, water horsetail (equisetum fluviatile) and rough horsetail (Equisetum
hymale) were exposed to 1 mg/L and 10 mg/L As(V) for 17 days. Plants were then separated into
root and shoot tissues, oven dried and digested with concentrated nitric acid to determine total
As concentrations though ICP-MS. Additionally, to investigate in situ arsenic species in plant
tissues x-ray absorption spectroscopic (XAS) analysis was completed on fresh root and shoot
tissues. Results show that E. fluviatile exposed to 1mg/L and 10 mg/L As accumulated an average
wet weight concentration of 0.5±0.03 mg/kg and 8.7±6.6 mg/kg in their shorts and 1.3±0.07
mg/kg and 19.7±8.2 mg/kg in their roots, respectively. E. hyemale treated with 1mg/L and
10mg/L As accumulated and average wet weight concentration of 1.4±0.1 mg/kg and 8.0±0.3
mg/kg in their shoots and 2.6±0.5 mg/kg and 19.7±8.2 As in their roots, respectively. These
results will be used to determine the candidacy of horsetail for incorporation into constructed
wetland systems treating arsenic contaminated wastewaters.
P8 – Jessica Henry
Arsenic speciation in mushrooms subject to thermal treatments
Arsenic is an element found in the environment in many different chemical forms (referred to as
species), each having unique chemical, physical and biological properties. The different species
range in their toxicities, with among the most toxic arsenic species including inorganic forms,
such as arsenite (As(III)) and arsenate (As(V)). Generally, pentavalent organoarsenic compounds
are less toxic and aresenobetaine (AB) is the only species considered non-toxic. Where there are
no natural or anthropogenic sources of arsenic contamination, food is the main source of intake
for this metalloid. Higher levels of arsenic are generally found in foods such as seafood, rice, and
sometimes mushrooms. AB is the principal arsenic form in seafood and many mushrooms
species. Preparations of food, such as cooking treatments, have been found to alter the arsenic
speciation in seafood such as the degradation of AB to dimethylarsinic acid (DMA), and
tetramethylarsonium ion (TETRA), as well as less prevalent amounts of arsenocholine (AC) and
monomethylarsonic acid (MMA). In this study, several edible mushroom species were collected
and treated to simulate cooking scenarios (barbequed, baked and fried). The samples were
analyzed for total arsenic using ICP-MS and for arsenic species using HPLC-ICP-MS. A consistent
decrease in the total arsenic concentration was seen in all of the cooked samples, in comparison
to their raw (untreated) concentrations. AB was found to be transformed to more toxic forms in
several samples. Therefore, it may be necessary to consider the effect of thermal treatments on
arsenical species when determining risk associated with mushroom intake.
P9 – Logan Morris
Arsenic in beer
Arsenic (As) is a naturally occurring element typically perceived to be a poison, but its toxicity
depends on its chemical form. Arsenic exists in different species in the environment and in food,
in both inorganic (e.g., toxic arsenate (As(V)) and arsenite (As(III)) and organic (e.g., less toxic
monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA)) forms. Recently, As has been
detected at low concentrations in foods such as rice as well as different commercially available
wines and beers. From 2012-2015 the Environmental Sciences Group (ESG) at Royal Military
College of Canada (RMCC) has been studying As concentrations in different commercially
available wines with a survey of over 200 wines showing that most wines available in Canada
have concentrations lower that the Canadian drinking water standard of 10μg/L. There is little
scientific literature on As in beer but recent studies have suggested a link between beer
consumption and increased As in toenails. The objectives of this project are to analyze the As
concentrations in different beers available in Canada, as well as to create a beer brewing
experiment that will be used to determine the effect of fermentation on the content and
chemical form of the As. Beer As concentrations are predicted to be similar to wine
concentrations, and on the basis of the RMCC wine study, the As species are predicted to be
predominantly As(V) and As(III), as well as small amounts of MMA and DMA. Beer samples (30)
were collected for the beer survey. Beer was bfrewed from a kit and divided into 4 experiments:
2 with no added arsenic and 2 with 100 ppb As(V). total As in all samples is determined by acid
digestion with detection by inductively couples plasma – mass spectrometry (ICP-MS). Species of
As are determined by high performance liquid chromatography (HPLC)-ICP-MS.
P10 – Xining Chen
Iron (III) oxide nanoparticles: a green option for the removal of organic pollutants and
atmospheric aerosols
Iron (III) oxide nanoparticles have been demonstrated to be an effective adsorbent for gaseous
organic pollutants. Together with their magnetic properties, iron (III) oxide NPs have the
desirable characteristics for a portable and recyclable pollutant remover; however, their nanosized particles are difficult to contain, therefore limiting their usage. The first step of our work is
to anchor iron (III) oxide NPs onto an environmentally friendly substrate to prevent the scattering
of NPs. Our second step involves investigating the potential of iron (III) oxide nanoparticles in the
adsorption of various types of atmospheric aerosols, especially trace-metal containing aerosols
which are often released from mining related activities. Our final goal is to develop a portable,
recyclable iron (III) oxide based pollutant remover which targets both toxic organic gaseous
products and aerosol particles.
P11 – Zhenzhong Hu
Adsorption of mercury vapor using iron oxides nanoparticles and subsequent recovery via
electrochemistry
Trace metals including neurotoxic mercury are found amongst common component of
atmospheric aerosols releasing from mining related activities. Elemental mercury (Hg0) can easily
vaporize and be inhaled into human’s body. Also, elemental mercury vapor can easily form the
methylmercury which is the most toxic of the most toxic of the organic forms and can easily
spread into the ecosystem. It is thus of great importance and interest to develop an efficient and
recyclable system for the treatment and recycling of element mercury. In our studies, we aim to
develop a mercury remediation system using naturally occurring materials. Meanwhile, by
combination with an electrochemical regeneration method, the sorbents and mercury can be
highly recycled with energy efficient and low cost. Selected physical and chemical properties of
nano-sorbents are analyzed by using high-resolution transmission electron microscopy, X-ray
diffraction, X-ray photoelectron spectroscopy, NanoScan and Brunauer-Emmett-Teller. Gas
chromatography–mass spectrometry (GC-MS) and cold vapour atomic fluorescence spectroscopy
(CVAFS) are used to estimate the removal efficiency and electrochemical regeneration efficiency
of mercury vapor. The specific results will be presented in the conference and the impact will be
discussed. The implication of the results for removal and recycling of other metals from mining
related activities will also be discussed.
P12 – Ibrahim Jreije
Detection, characterization and quantification of engineered nanoparticles using single particle
inductively coupled plasma mass spectrometry
Due to their nanometric size, their high reactivity, and their interesting properties, the
engineered nanoparticles (ENPs) are becoming more widespread in industrial and consumer
products. Many ENP-enhanced products are directly exposed to the environment and ENPs can
be released from these products to aquatic systems. In the interest of fully assessing
environmental and public health risk, the specific objectives of our research are to detect,
characterize and quantify ENPs released from paint and paper products (Ag, TiO2, SiO2, etc.) in
environmental matrices using the inductively coupled plasma mass spectrometry (ICP-MS) in its
mode single particle (SP). With SP-ICP-MS it is possible to determine size distributions for ENPs
by using the transient intensity of MS signal to determine the size of the metal species (dissolved
vs nanoparticle). Our goal is to use SP-ICP-MS, in order to quantify the concentration and size of
a suite of target ENPs in complex matrices.
Results will be presented for initial experiments that have been designed to optimize the SP-ICPMS (measurement times, type of nebulizer, etc.). In a second step, the role of media composition
(e.g. pH, ionic strength, presence of dissolved organic matter, Ca, etc.) will be evaluated for
standard nanoparticles (such as Ag, Au, etc.). Initial experiments are designed to increase the
reproducibility and the validity of the technique when used for diverse weathered samples, later
in the project.
P13 – Geneviève Rioux
Influence of temperature on copper speciation in natural water
Copper is an essential element for plants and living organisms, but it can become toxic at high
concentrations. In natural water, copper speciation allows us to predict the bioavailability and
toxicity of this metal. Natural organic matter (NOM) is the main complexing agent of the free
copper ion. Until now, research on copper speciation in natural water has been carried out at
room temperature whereas the temperature of lakes and rivers is often well below 20°C. since
temperature can possible affect the speciation of metals and their bioavailability, we wanted to
investigate the effects of temperature on cupric speciation in presence of natural organic matter.
In the samples, the concentration of Cu2+ has been determined with a copper ion-selective
electrode (Cu-ISE). This method was chosen because it allows u to determine directly the
concentration of the free metal species. Samples were analysed at both 4 and 20°C with the CuISE. The ion strength was 0.01 M KNO3, pH was maintained at 7.0±0.1 and the initial copper
concentrations were respectively 10-6, 10-5 and 10-4 M Cutot. Three different concentrations of
humic acid were tested (10, 25 and 40 mg C/L). according to our experimental results, the
influence of temperature on free Cu2+ concentrations is only significant at humic acid
concentration of 40 mg C/L. In most common natural waters, the concentration of NOM is
approximately 5 mg C/L. we thus conclude that temperature will not significant affect the
speciation of copper ion in natural water.
P14 – Cui Lei
The role of heavy rare elements in northern Canada environments
Over the past decade, the global demand for rare earth elements (REE) is increasing, and
numerous countries are looking to exploit REE deposits. Canada’s North holds abundant mineral
resources. The bioavailabilty of the REEs are influenced by geochemistry and the aquatic
environment in which they are found.
The proposed research is to understand the role of REE speciation in their toxicity and
bioavailability in a typical northern Canadian environment. Our research is focused on the heavy
REEs (Ytrium and Thylium). The ion exchange technique (IET) and equilibrium dialysis methods
will be used for determining the speciation of Y and Tm in the presence of natural organic matter
(Fluvic acids – IHSS Standards). Y and Tm bioaccumulation experiments will use the unicellular
freshwater alga (Chlamydomonas reinhardtii), and short-term metal exposures. Samples are
analysed using ICP-MS.
Preliminary results have shown that bioaccumulation of these REEs in the presence of natural
organic ligands do not follow the biotic ligand model (BLM). The next step will be to further verify
the results.
In addition, we would like to measure REE concentrations and speciation in sampling sites from
regions near to mining deposits which could have high REE contents. This project falls within the
context of performing ecological risk assessments on these emerging metals.
P15 – Matti Ruuskanen
Microbial community responses to toxic metal pollution during the Anthropocene
My thesis aims at providing new information on the impact of anthropogenic toxic metal
pollution on microbial communities, with a particular emphasis on their toxic metal resistance
evolution since the Industrial Revolution.
I am focusing on three research questions: (i) Can we track historical toxic metal deposition
through changes in microbial communities and/or their metal resistance genes; (ii) what are the
unknown novel toxic metal resistance strategies that exist in the environment, in particular in
anaerobic and cold conditions; (iii) who are the actors (bacterial and archaeal species) involved
in toxic metal cycling under geogenic and anthropogenic pressures? As initial proof of concept,
my work will focus on microbial Hg resistance.
The application of novel lab techniques, combined with both an original sampling strategy and
unique computational approaches, is expected to unravel the effects of historical toxic metal
loading on environmental microbial communities and their resistance genes. The identification
of amino acid sites involved in detoxification, and changing through time, can have a dual use: as
a biomarker of historical toxic metal deposition, and as a genetic construct that can be inserted
in bacteria for remediation of metallic contamination. Our remediation arsenal and strategies
will also be expanded by identifying novel genes involved in toxic metal cycling in cold and
anaerobic environments. Through charting the changes caused by historical toxic metal loading
in the bacterial communities harboring resistance genes, I will also uncover new phyla involved
in metal resistance.
P16 – Kelli Charbonneau
Morphological deformities indicate the chronic toxicity of chemically-dispersed dilbit to
rainbow trout embryos
This research responds to knowledge gaps and concern about potential spills of dilbit (diluted
bitumen) in freshwater. While pipelines carry dilbit from Alberta’s oil sands over 3300 kilometers
of terrestrial and aquatic systems in Canada, relatively few studies have measured its toxicity and
environmental fate in the event of a spill to freshwater ecosystems. This study demonstrated a
relationship between a gradient of dilbit concentrations and toxicological responses in
developing fish embryos. Chronic toxicity was measured by exposing rainbow trout embryos for
25 days to six nominal loadings of two different winter dilbit blends, Cold Lake Blend (CLB) and
Access Western Blend (AWB). Chemically enhanced water accommodated fractions (CEWAF) of
CLB and AWB dilbit were used to prepare exposure solutions. Endpoints to characterize the
toxicity of dilbit to rainbow trout embryos included mortality, impaired growth and development,
and onset of blue sac disease (BSD). The concentration of total petroleum hydrocarbons was
measured in exposure solutions by fluorescence intensity. While analyses are ongoing,
preliminary results indicate that mortality increased with higher nominal loadings of dilbit
CEWAF. Both dilbit blends caused similar toxic effects, and the prevalence of sub-lethal
morphological defects (i.e. onset of BSD) increased across a gradient of loadings of dilbit. Results
from this study facilitate comparisons of chronic toxicity between dilbit and conventional crude
oils, for which toxicity and environmental behavior have been described in detail in the literature.
P17 – Jason Colligan
Removing plastics from the environment
Plastic waste is everywhere in our environment. It enters our streams, lakes and oceans as well
as collecting at water treatment plants where it is sent to landfill. The majority of the waste in
the ocean garbage patches are plastics of various sizes. One group of plastics that are a cause of
concern are micro-plastics, polymer particles greater than 0.1 μm and less than 5 mm in
diameter. The government of Canada has purposed microbeads be considered toxic under
subsection 64(a) of the Environmental Protection Act, 1999 (Environment Canada, 2015).
Scientists have found micro-plastics in the Great Lakes at values exceeding 500,000 pieces per
km2 (Mason et al. 2013).
My thesis will be examining possible thermochemical techniques for removing plastics waste
from the environment and possibly converting the waste into fuel. For example, stream
gasification, pyrolysis techniques, and combustion will all be examined as viable alternatives to
landfilling of plastics (or throwing them in the water ways). As landfill space declines and tipping
fees become higher, economics will be examined on whether it is feasible to convert plastic
biomass to a transportation fuel with the addition of the tipping dee going to the plastic
conversion process. Also, some waste water facilities collect plastics and micro-plastics and this
waste will be examined. The work will be both computational and experimental.
P18 – Laura Ogilve
Characterizing the start up and development of aerated and non-aerated constructed wetland
mesocosms
Constructed wetlands are gaining attention as a viable alternative to current secondary and
tertiary wastewater treatment methods. Constructed wetlands aim to mimic naturally-occurring
wetlands and their processes for pollution removal such as sedimentation, filtration, chemical
precipitation, microbial interaction, plant assimilation and adsorption to soil particles.
Constructed wetlands have been used to polish many types of wastewater including those from
industrial, agricultural, residential and stormwater sources.
Twelve lab scale constructed wetlands were designed, built and inoculated with undiluted
activated sludge from a local wastewater treatment plant. Half of these constructed wetlands
were artificially aerated and all were planted with reed canary grass, Phalaris arundinacea. The
wetlands were allowed to naturally develop over a period of two months. Water quality,
wastewater treatment ability and microbial community characteristics were monitored over this
time. Daily measurements of water quality parameters were taken, such as dissolved oxygen,
ammonium nitrogen, nitrate, pH, oxidation-reduction potential, and temperature. Water
treatment ability of the wetlands was assessed via total organic carbon and total nitrogen
removal, as well as nitrogen cycling. Total microbial community activity of the wetland interstitial
water was characterized using fluorescein diacetate hydrolysis. Microbial community functional
diversity was measured with Community Level Physiological Profiling which characterizes the
ability of the wetland microbial community to utilize different carbon sources as food.
P19 – Rodrigo Rangel-Alvarado
Ice nucleation of nanosized particles of inorganic composition
Sustainable mining involves in-depth consideration of environmental impacts. In this research we
study to the role of particles in nucleation, which leads to not only formation of clouds but also
reduction of visibility and air pollution around the mining sites, which affects the quality of life of
the communities living nearby. It is known that ice in clouds can form spontaneously from pure
water, but the temperatures at which this happens are extremely low. The presence of particles
facilitates ice formation by providing a nucleus, on which ice can start growing at temperatures
closer to the melting point of water. Trace metals are found amongst common component of
atmospheric aerosols released from mining related activities that can affect ice formation.
Moreover the ice nucleation process exhibits dependency on chemical composition as well as the
size of participating particles, larger particles being more efficient. In summary, many models of
cloud formation don’t take into account the possible contributions of a fraction of aerosols. We
herein show the existence of aerosols from < 100 nm to ~ 1 μm in diameter of possible inorganic
composition within snow that could be responsible for the nucleation of ice clouds where the
snow formed. We will present our data on number density, size distribution and ice nucleation
to metals from mining related activities in the ice nucleation process will also be discussed.
P20 – Ahmed Khafhafera
Microalgae as a sustainable energy source for cement plants
Cement is the second most utilized material in the world, following only water. Based on recent
statics, the global cement consumption is increasing by 5% annually, which was 4060 MT in 2014.
Cement manufacturing is the largest source of industrial carbon dioxide (CO 2) emissions; the
large carbon footprint resulting from both combusting fossil fuels and decomposition of
limestone. In total, cement accounts for 9.5% of the global CO2 emissions. The current industry
trend is to substitute the fossil fuels with alternatives, often biological in origin. Microalgae is a
popular choice for capture the C02 emissions from cement plant due to the high capability of
carbon fixation (1 kg of microalgae captures approximately 1.8kg CO2) and co-benefits of SOx and
NOx reductions. The aim of the project is to establish a net zero carbon system within cement
manufacturing sector. The experimental procedure would be culturing microalgae using cement
flue gas, harvesting the algal biomass through electrocoagulation process, and then making algal
briquettes to be fed into the calciner. Electrocoagulation is an effective process to harvest
microalgae (99.5% TTS as highest yield at 0.8-1.5 kWh/m3). The process is based on ion
dissolution from the electrode acting as a coagulant. Interestingly, cement contains iron and
aluminum corresponding to a specific ratio (4AI:1 Fe), which can be achieved through the
dissolution of the sacrificial anodes. A mixture of algal biomass, AI/Fe, and CaCO3 will be used in
the briquettes to be suitable for storage and burning with desirable calorific value required by
the cement kiln.
P21 – Stevan Ostojic
Drying of brewer's spent grain for use as a biofuel
Brewer’s spent grain (BSG) is the major biological waste product from the beer brewing process.
Considered a waste product, it is typically disposed of either as feed for husbandry or simply to
landfill. The main challenge to BSG utilization is the high moisture content, anywhere from 77-
81% (w/w) (Mussatto, et al., 2004). Therefore, a cost and energy effective drying method would
increase its storage time and enable it to be used as a biofuel among other uses. There has been
some research in drying brewer’s spent grain, including using a fan, superheated steam, and a
membrane filter press. In this study we look closely at grain drying using forced, heated air
through a fixed bed of BSG. The BSG moisture content will be compared to air flow rate, air
temperature, exit air moisture and fixed bed pressure. All of this will be accomplished in a custom
laboratory apparatus that measures pressure drop across the bed, temperatures and humidity
of the exhaust gases. The dried BSG will then be compacted and its energy content determined.
This will enable an economic analysis of BSG. Concurrently, a pilot scale drying system will be
employed at the Gananoque Brewing Company to dry and pelletize BSG for use as a heat source.
Alternative end uses, such as flour substitute in breads, will also be investigated.