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>> Tom Zinnen:
Welcome, everybody,
to Wednesday Nite @ the Lab.
I'm Tom Zinnen and I work here
at the University of
Wisconsin-Madison
and for UW Biotechnology Center
and for UW Extension.
Welcome to Wednesday Nite
@ the Lab.
Tonight we have
Joanna Skluzacek, the new
state specialist in STEM,
which is Science, Technology,
Engineering, and Math,
at the University of Wisconsin
Extension.
She's a 4H state specialist and
I'm very much looking forward to
getting to work with her over
the next few months, next few
years, because it's going to be
great to have more science and
technology, engineering, and
math opportunities for 4H youth
across Wisconsin.
Joanna was born in Lonsdale,
Minnesota and went to Mankato
State.
She got her PhD at the
University of Wisconsin-Madison
in 2005 in Environmental
Chemistry and Technology.
Then she went to Penn State as a
post-doc during which time she
spent a couple of years in Ghana
as a National Science Foundation
Discovery Corps member.
She came back to UW-Madison,
excuse me, UW Extension here in
Madison on May 14 of 2010, and
like I say, it's really great to
have this and this greater
capacity to serve young people
and give them opportunities in
science through 4H in Wisconsin.
Joanna will be talking about
water quality concerns and
remediation strategies for rural
Ghana in Africa, connecting
science and society.
Please join me in welcoming
Joanna to Wednesday Nite
@ the Lab.
( applause )
Oh, wait a minute now,
I have to test it.
( taps microphone )
>> Joanna Skluzacek: Okay,
I turned on my microphone so
hopefully everyone can hear me.
Thanks, Tom, and thanks,
everyone, for coming this
evening to hear about my talk.
Again, I just started and it's
really great to be back here in
Madison as a 4H STEM specialist.
I've been away for about five
years at Penn State, so it's
nice to be back.
Today I am going to talk to you
about some research that I did
in Ghana, Africa, as Tom said.
I did this as part of a National
Science Foundation grant in
collaboration with Penn State
and the Center for Nanoscale
Science at Penn State, so I just
want to make sure I give credit
where credit is due.
That's where the funding came
from.
Today I'm going to talk a little
bit about my experiences in
Ghana and some of the water
quality research that I had done
and some of the things I
encountered while traveling in
Ghana.
It was definitely a new
experience for me and I learned
a lot, and I'm happy to share
that with you tonight.
First I just want to sort of
talk just a little bit about
environmental research.
I think everyone in this room
probably has a pretty good idea
that environmental research
doesn't occur in a black box.
There's a lot of other things
you have to consider when you're
doing environmental research,
and definitely when you're doing
environmental research in a
totally new environment, as I
was, coming from Pennsylvania
and being trained in the United
States and going to a developing
country like Ghana.
And so there were a lot of
things that I tried to prepare
very well for, some things I was
really naive about, and I'm
happy to say that this project
was successful, but sometimes
fairly stressful.
And things you need to consider
are sort of the cultural, the
socioeconomic, which is a very
large difference between here
and Ghana, and then other types
of rules and regulations that I
wasn't quite aware of when I
first got there.
Luckily my time there was fairly
long so I got to sort of work
those things out.
And what I did was, I did water
quality research on water bore
holes.
And you can see those in these
pictures right here.
This is a very typical bore
hole.
You can see a cement structure
and a pump, and here I am
pumping the pump, and we collect
water samples.
And these are found in a lot of
different rural villages in
Ghana.
For instance, here's another
picture of that.
So what am I going to talk about
today?
I am going to focus specifically
on some environmental concerns
in this certain region of Ghana
called Tarkwa.
I want to make it very clear
that I am not an expert on
Ghanaian government or Ghanaian
culture in any way, shape, or
form.
I was trained as a scientist,
but I can share with you some of
the things I learned while
traveling there.
Primarily, I went there, and
what was important as far as
finding funding for this project
was the significant gold mining
operations that occur in the
western region of Ghana.
And so this is definitely a
drinking water concern for the
villages and I'll explain a
little bit more about that as we
go along.
One of my project goals, or a
project goal I'm going to
discuss tonight, is, how can we
determine the impact of mining
on groundwater resources or
water resources that villages
are utilizing for drinking
water, for all of their daily
needs.
And then I'm going to talk about
some of the challenges that I
encountered along the way.
And I'm going to go into a lot
of the sort of chemistry and
analytical methods and talk a
little bit about how I actually
got some of the results, because
it's been very different than
maybe some of the talks you've
heard here at Wednesday Nite @
the Lab, where researchers are
doing work, say, at a UW
laboratory.
The facilities are quite
different, as you might imagine,
and so I can talk a little bit
about how the methodology is
different.
I'm going to discuss my results
and some of the remediation
strategies that we worked to
develop as we were going along.
There was just one more thing I
wanted to introduce before I get
into the main bulk of my talk.
This is mainly just to make sure
that we're all sort of on the
same page when I start talking
about different things that are
occurring in Ghana at this time.
The big difference is between
economic and physical water
scarcity.
As you might imagine, we have
some water scarcity issues right
here in the United States and
this red indicates a physical
water scarcity, and we see that
in the western United States.
Basically, there's not a lot of
surface water, it doesn't rain a
lot, it's a very arid
environment and so we have water
scarcity problems in the western
United States.
What's a little bit different
for areas in Africa would be,
it's an economic water scarcity.
Most people, when they think
about doing work in Africa as a
continent that it's a very arid
place, a lot of desert.
That's really not the case in
southern Ghana.
Southern Ghana has a tropical
climate, it rains all the time,
it's a very high water table, it
has a lot of rivers and lakes.
However, there's economic water
scarcity, meaning that there's
not the infrastructure in the
country to transport water, to
purify water, to distribute it
to the masses in a safe
and easy way.
So that's what we mean by
"economic" water scarcity
issues.
I was in Ghana.
This is the African continent,
of course.
Ghana is this little country
right here.
The equator actually runs right
along here just to the south
border.
This is a close-up view, and I
was in a town called Tarkwa, as
I said.
It's in the southwestern region.
As I said before, there's a lot
of water resources in Ghana.
You can see here, it has an
extensive river and lake system.
This is the Volta region.
Actually it gets quite a bit of
hydroelectric power in this area
because of the damming of the
Volta River.
In Tarkwa it's very close to the
equator and like I said it has a
tropical climate and it rains
quite a bit, lots of vegetation,
etc.
When I went to work there, I
actually got connected with a
university called the University
of Mines and Technology, or you
might hear me refer to it as
UMaT, which is actually
stationed in Tarkwa, Ghana.
It's basically a mining
university because of all the
gold and diamond mining that
occurs there.
But as we'll talk about, they're
starting to become a little bit
more aware of some environmental
concerns and when I decided to
write a proposal, I had some
colleagues who had worked in
Ghana before.
I got connected with the
professors and faculty at this
university and they were real
excited to have a US researcher
come and do some work.
Basically what I'm going to be
talking about is mining industry
impacts on water quality, or how
we were trying to assess that
with my project.
This is to give you a little bit
of idea of what is going on as
far as mining industry in Ghana.
So this is a graph that's taken
from Dr. Richard Amankwah in
2003.
He was actually one of my
collaborators at UMaT.
Here you can see production, and
this is either in gold ounces or
this could be diamond carats.
You can see diamonds that are
two lines here.
And the gold are the blue
circles or blue triangles here.
What we saw in Ghana, say,
pre-1990 or sort of the early to
mid '80s was, there wasn't a lot
of gold production in the
country.
Ghana was going through a lot of
transitions in the '50s and
'60s, gaining independence.
In the mid '80s, a very
significant thing happened.
The government implemented
something called the economic
recovery program.
Now, this economic recovery
program basically stated that
now manufacturing and mining
operations could be
foreign-owned, or foreign
investments would be taken to
supplement or increase the
mining and manufacturing
capacity in the country.
So what they started to see from
about the beginning of the 1980s
through current times is that
they had a significant increase
in the total production of gold.
And this is mainly because of
the foreign companies coming in
and being able to put money and
capacity into the mining
processes.
One thing I do want to mention
is, so this is total gold
production and this little line
here is what we call "small
scale" gold production.
So small scale is also called
"artisinal" gold production.
It's been occurring for
centuries in Ghana and a lot of
other places.
The difference between these two
lines then is large scale mining
operations.
I'm going to be talking a lot
about large scale mining
operations, so I just kind of
want to give you an idea of how
much production is happening
currently in Ghana.
This continues to increase,
definitely with the changes in
the global economy.
Gold is in high demand.
So this picture here is a
typical large scale gold mining
operation.
Tarkwa is a town about, I would
estimate, a quarter of the size
of Madison.
That's about the size of the
town.
The population has grown
dramatically because of these
new mining companies, but
currently there's about five or
six of these large scale mining
operations occurring in that
area.
The western region is where
about 85% to 90% of Ghanaian
gold is mined, and in the Tarkwa
region a significant portion is
mined.
So this is a pretty typical
mining operation.
You can see the sort of spent
ore slags, you can see the
mining equipment.
This is what it normally looks
like.
As I said, it's a very tropical
area.
This was just outside my house.
This is what I looked at every
day.
Lots of vegetation, high
rainfall.
The mining operations,
of course, you are changing
the environment.
They use slash-and-burn
technology quite a bit,
clear-cutting technology, to
remove the vegetation and then
really just start to dig.
As you can probably expect,
they're starting to see some
significant environmental
effects of these types of
practices.
Again, this is a large scale
mine.
You can see the ore coming here.
One thing to talk about, when we
talk about the difference
between large scale mining and
small scale mining, is the way
gold is extracted from the ore.
In large scale mining
operations, cyanide is used to
extract gold from ore.
As we probably know, or I can
refresh your memory, cyanide is
a pretty potent poison.
However, it's really good for
extracting gold.
These large silos, as you can
see here, maybe I can...
These silos as you see here
are filled with cyanide.
And you'll normally see about 20
of these large silos on any
typical large scale mining
operation.
They take the ore and put it in
these silos.
They mix it and they do their
processing, and then the sort of
spent liquid comes out these
pipes.
And I'm sorry I didn't get a
better picture, but they didn't
really like me to be where I was
standing.
They come out in sort of
receptor pools, where then it's
treated and released into the
environment.
In some cases it can be reused
several times, the same cyanide.
However, spills do occur and
quite often you'll hear about
large fish kills occurring
because cyanide accidentally
spilled into the environment.
And people are very concerned
because the spills are happening
more frequently as production is
increasing.
Small scale mining is a little
different process.
Small scale mining is something
we might think about when we
think about in the early days of
the United States when people
went out to California to pan
for gold.
That's basically the process
that these miners are utilizing.
They're usually on a riverbed or
streambed and they're panning
for gold.
However, gold is becoming harder
and harder to get out of these
deposits.
The main way small scale miners
extract the gold is to use
mercury.
Now mercury, again, is a
significant health hazard.
Some may say that it's more of a
health hazard than cyanide just
because of the way mercury can
continue to deposit in the
atmosphere.
The way they use it does
definitely lead to that.
This is a typical miner and he
has some mercury and some ore in
a bucket.
They don't use any protective
equipment, so they usually just
mix it with their hands.
In some cases they'll use
smaller receptacles with cloth
and they'll actually, by mouth,
they'll suck the excess mercury
out of the cloth because it's a
very important chemical for
them.
It's expensive and it's hard to
come by, and so they'll suck the
excess mercury out and actually
spit it into a container to be
used again.
Once this process is done they
actually fire it at a very high
temperature and then burn off
the excess mercury and end up
with something like gold
bullion.
Now, since they're on the
streams, this mercury can get
into the water system.
But what's also important is,
when they burn off excess
mercury, mercury will go into
the atmosphere and so it can be
transported to a very large
distribution area, which then is
a concern for almost everyone in
the country.
There are some significant
things that we have to keep in
mind.
We wanted to take a look at
maybe what are some of the
impacts of these things, at
least in the most recent times.
This is a typical sampling site.
Another thing, and this is not
specific to Ghana, you'll see
this in almost all developing
countries, that accessibility to
water is also problematic.
There might be one bore hole
well in the village and so
that's where everybody has to go
and they might trek some
distance to get there.
So people line up for basically
hours for their turn at the bore
hole pump to fill up their
container to take it home and to
use it for all of their uses
during the day.
Everything from drinking to
bathing to laundry to cooking.
Quite often, we sampled during
the week and weekdays, usually
about 9am to 6pm.
We always saw children at these
sites collecting water.
That just is another thing that
we need to keep in mind when we
start talking about the
relationship between access to
clean water and accessibility to
water, and also economic
development of a country.
We talk about children not being
able to go to school because
they have to do these chores and
things at home.
It's a big problem when we start
talking about children
developing and becoming literate
citizens.
These are some of the samples
that we would see.
It ranged anywhere from fairly
clear to very turbid and most of
the time people were drinking
this water directly without any
further purification.
As I said, we were focusing
mainly on the mining operations.
There were a lot of different
things we could have focused on,
but this is one of the areas
that we wanted to really look
into.
As I said, for large scale
mining, what we wanted to look
at is, we wanted to take a look
at some cyanide concentrations
and see if we could actually
find any cyanide in the
groundwater.
Probably we would find low
levels, if any.
Cyanide breaks down fairly
quickly, definitely in the
groundwater.
But we were also looking for
other indicators such as
sulfates from acid mine
drainage, and nitrate.
Nitrate initially wasn't one of
our sort of priorities.
However, we were starting to see
significant concentrations of
nitrate.
When we think about testing our
wells for nitrate in, say, the
rural United States, we're
normally looking for pollution
caused by fertilizers, human
waste, etc.
And we thought that would be a
concern here, but what we were
actually finding was that it
wasn't from waste or
fertilizers, it was actually
from blasting.
They used a lot of explosives,
of course, for the large scale
mining.
They would do a lot of blasting,
it would make your house shake.
It scared me almost every time
it happened.
So they use a lot of TNT and of
course the "N" in TNT
stands for "nitrogen."
They also use some other types
of explosives that have nitrate.
So that also gets into the
environment, so we were looking
for those markers as well.
The small scale mining, as I
mentioned, mercury was something
we wanted to take a look at.
Testing for mercury is really
difficult, so we sort of did the
best we could.
I can show you sort of our
results a little bit later.
We did look for other things
since we were out sampling, we
wanted to try to test for as
many things as we could with the
facilities that we had.
So we did test for lead and some
other transition metals, and
bacteria, etc.
I'm not going to discuss that in
detail, but if you have
questions at the end, feel free
to ask.
I'd be happy to talk a little
bit more about that testing.
Some of the challenges, as you
might suspect, first of all
would be analytical equipment to
do this sort of testing.
If you're living in rural Ghana,
you have some very significant
factors that you have to think
about when you're doing
analytical chemistry, one of
which is a lack of electricity.
Electricity would go out daily
and would be out anywhere from a
couple of hours to a couple of
days.
Not very good for
instrumentation if they had the
capacity to actually buy a
spectrophotometer or something
like that.
Actually, my grant supported the
purchasing of a lot of water
reagent kits and also things
like pH meters, dissolved oxygen
meters, etc.
Things that they didn't have
access to at all, which was
great, except it made budgeting
a big headache.
Because not only then are you
looking at the cost of supplies,
you have to purchase them from,
well, the US or from Europe.
They also had to be shipped to
Ghana, Africa, so that was
really difficult because we were
looking at shipping costs that
rivaled the cost of the
materials we were using.
So that was a significant
expenditure and I could have
utilized that money a lot
differently if I wouldn't have
had to spend it on the shipping.
Also the timeline for materials
to get there.
Some chemicals that we used,
some extraction acids and bases
cannot be air shipped to Ghana
or certain areas in Africa
because of regulations, so they
have to go by boat, which, of
course, will take several months
to however long it may take for
the ship to come into port and
then for the ship to be
unloaded.
Ghana still relies
on the chieftaincy -
( flubs pronunciation )
Chief system!
There, I got it out finally.
And so every region will have
sort of their own way of doing
things.
This process to ask permission
from the chiefs can be very
elaborate to very easy, but you
don't really know that until you
actually get there and you want
to try to sample their bore
holes.
Community information and
language.
English is actually the national
language and that was one of the
reasons why I wanted to travel
there.
But as you can see from the last
point, English isn't necessarily
the best language for me either,
but I wanted to gather some
community information.
Most people in the rural areas
will speak their local language,
which is Twi, which is not
intelligible for me.
So I also had to always have
people accompany me when I went
sampling for other reasons as
well, but also the language
barrier was fairly significant.
Also, cultural stigma.
For good reason they asked me a
lot of questions about whether I
was with the mining company and
why anyone from the United
States would come to rural Ghana
to do water sampling.
I can understand definitely
their stigma.
The mining companies have taken
a lot from them in the last 20
years and significantly before
that.
So it was also a matter of
trying to get folks to trust me,
to talk to me a little bit, and
that of course took time as
well.
This is a pretty typical house.
Thatched roofs, clay sides, so
that's normally the dwellings
that we were living in.
Again there's some kids.
The kids really thought it was
pretty cool to watch me sample.
In almost every picture I have,
the kids are there.
Sometimes I couldn't even get a
picture because the kids were
crowding all over.
But it was cool, I loved it.
The methods I used were not
necessarily what you might think
of as the most expensive or...
high-end sort of equipment.
I used something called the
LaMotte test kit.
These are basically surface and
groundwater testing kits and the
unit, as you can see here,
is fairly simple.
It's a fairly simple what we
call spectrophotometer, which
means that it detects color
changes.
So what we do is, we have our
water sample and we put those in
the little vials and we add some
reagents.
If that pollutant is present,
the reagents will change the
water a certain color and our
instruments will be able to
detect that color change.
So if it's used very carefully,
and we would always use
standards to make sure that we
were calibrating things
correctly, we always tried to
use check samples.
If they're used carefully, you
can actually get very good
readings from low-cost
instrumentation like this.
As long as the levels of
pollutant that you're looking at
are fairly high.
They don't have very good limits
of detection, is what we call it
in sort of the scientific
community.
So if the pollutant is in really
low levels, this isn't really
the best way to analyze.
However, we were looking at some
health effects for some very
significant chemicals and we
were finding those in fairly
high concentrations.
That part wasn't too much of an
issue.
We had sample bottles that we
shipped in that were sterile and
acid washed.
Another sort of problem that
occurred is, I had to do all the
analyses within 24 hours.
Usually water samples, you can
preserve them, but since we
didn't really have any
refrigeration, that became a big
issue.
So we tried to keep the samples
as cool as possible.
That just meant that we had to
have multiple sampling trips,
and so we were going out quite
frequently to collect a small
amount of samples, so then I
could go back to the laboratory
and analyze them within 24 hours
for all the analytes.
This made things a little bit
more difficult and we probably
could have done much more
sampling if we wouldn't have had
the problem of trying to get
transportation to the sites as
often.
Let's start talking about some
of the results.
As I said, for large scale
mining operations, we were
looking for some key pollutants.
First of all, I'm going to talk
a little bit about sulfate,
sulfur, and nitrates, which is
this right here.
And so here on this axis is
concentration in milligrams per
liter, you can say "parts per
million" if you'd like.
These are the ten sites that we
focused our study on.
Initially we sampled about 50
different sites and then what we
did is, we tried to weed out
some of the sites and determine
what might be the most effective
and efficient way to utilize our
facilities and our funding.
We tried to focus on ten sites
around the city, fairly close to
large scale mining operations.
Also, accessibility to these
sites was a factor and also if
we were allowed to sample or
not.
Sometimes the chief said, "No,
you can't sample," and so then
we couldn't do that.
These are the ten sites that we
picked.
This first one here, UMaT,
that's a bore hole that's
actually on the college campus
that people use for drinking
quite often.
And then these other sites.
This is what we were sort of
seeing and this will become more
significant as I talk about some
of the other results.
In Akoon, Simpa, and Aboso, we
were seeing significantly higher
levels of sulfate and nitrate
than the other sites, which were
sort of what we were seeing as a
baseline.
Akoon, there was a lot of
nitrate and this, as we found
out by talking with some of the
villagers, they had been
actively blasting in that site
quite often for the months up to
when we were sampling.
Another thing we wanted to know
is if the nitrate was actually
because of sanitation problems
in the village versus the mining
operations.
That's very hard to determine
because sanitation is,
of course, an issue.
There's no indoor plumbing, so
normally latrines are used.
However, we didn't find any
bacterial contamination in this
particular sample, which tells
us that it's probably not fecal
coliform bacteria.
The nitrates might be coming a
little bit from sanitation, but
we think that it's mostly from
the blasting, or at least that's
what our assumptions came to.
If we move on to cyanide, this
graph looks really scary, but
it's not, because the
concentrations here on the axis
are very, very low.
Actually, pretty close to our
limit of detection.
The WHO guideline for cyanide
is 0.07 milligrams per liter.
As you can see with all of the
sites, we are well below that,
at least ten times, if not more,
below the WHO guideline.
Cyanide, very low levels, it was
really hard to detect, as you
can tell by some of the error
bars here, just because the
levels were so low and our
equipment wasn't really capable
of going much lower than this.
That was good to see that we
didn't see any spiking effects,
at least for cyanide, for
samples that we looked at.
Mercury again is, as I said
before, fairly hard to monitor
in the environment.
The WHO guideline for mercury,
0.006 milligrams per liter,
which is also
this black line here.
Our limit of detection for our
instrument was, I believe,
0.03 milligrams per liter.
So this data is very hard to
take and say anything about
significant differences in
sites, or about statistical
comparisons.
However, we did see something
that was sort of interesting
when we looked at it alongside
our other sites.
For example, Aboso, Akoon, and
Simpa, again we were seeing a
little bit higher levels than in
the other water samples.
We saw this pattern for a lot of
different things that we looked
at in these three particular
sites.
So research is still ongoing at
those sites, at least, and we
wanted to continue to see if
there were some changes here in
the mercury concentration
because of small scale gold
mining.
As I said, we did do some other
sampling, so this just gives you
a snapshot of some of the other
pollutants that we tested for.
We tested for molybdenum,
manganese, and lead.
We're probably most familiar
with lead.
Lead, of course, is fairly
harmful.
It's definitely harmful to
children as far as cognitive
development and it's also sort
of a neurotoxin.
So the WHO guideline
is listed here, 0.01.
All of the ten sites had levels
well above the WHO limit of
safety for drinking water,
which is very problematic.
Manganese, most of the sites,
again, had higher levels than
permitted by WHO.
We saw the same thing with
molybdenum.
This is really a problem and
although we cannot specifically
link this to the mining
operations, we can make a few
generalizations about why these
might be showing up in the
groundwater system.
As I said, because Ghana is sort
of a topical environment, its
water table is quite high.
Within about five to ten meters,
you'll actually find water if
you dig a hole, okay?
So these mining operations, of
course they're going far deeper
than that.
We're talking about hundreds and
hundreds of feet to do the
mining.
So we know that it's having some
sort of influence on the
groundwater system and we know
that as we change and expose
some of these minerals that
these elements are in,
we change the oxidation states.
We expose them to oxygen when
maybe they weren't exposed to
oxygen before.
Or we changed the pH of the
system because of acid mine
drainage.
So that will change some of the
solubility of these guys, and so
we might be able to see higher
levels of these sort of
contaminants in mining
operations.
However, that's sort of a leap
and there's no definite way to
really track this.
As far as lead, I can tell you
that about ten years ago they
stopped using leaded gasoline,
maybe a little bit more, ten or
fifteen years ago they stopped
using leaded gasoline, but it
still could be getting into the
environment, and for at least
the small scale and large scale
mining operations, they still
use lead batteries for lighting
in the mines.
The spent batteries are normally
just discarded in the mine when
they're finished and so that
could also be a factor with
lead.
However, like I said, we don't
really know.
A little bit of gloom and doom
there, sorry about that.
But in some sites we did find
that the water was actually
fairly good.
We did have some problems with
some metals, but in some cases
the water was close to safe for
drinking, that's what I can say.
We knew we had these problems,
we knew we had problems even
going in, though we couldn't
necessarily say what kind of
problems we had and what areas
we were looking at.
However, we really went into
this with a mindset of, well, if
we have these problems, how can
we find ways to help these
problems?
How can we make their drinking
water a little bit better?
How can we utilize local
resources and do some local
education to try to keep people
more safe?
Sand has been used, sand vats,
so basically, pouring your water
through a large container of
sand.
If it's very fine sand, it will
remove a lot of the particulate
matter, so the larger pieces of
junk that you might find in
there.
That can help purify your water.
But we also know clay has some
very interesting characteristics
that we might be able to utilize
for water purification.
Clay is, of course, the same
kind of clay you dig out of the
ground, and you can find it in
Ghana as well as clay soil.
Clays are sort of an interesting
thing, because clay's backbone,
or most clays, are aluminum,
silicon, and oxygen.
And these atoms come together
and they form the basic
structure of most clays.
Now, when these atoms come
together, what it does is, it
imparts a slight negative charge
on the surface of the clay
material.
So this means that the clays
then have a slight negative
charge to them.
The pollutants that I was
talking about, things like lead,
mercury, we talked about iron,
we talked about these transition
metals, many times when they're
dissolved in water they're
positively charged.
They become ions.
So plus one, plus two, plus
three, they have a slight
positive charge.
What we can start to think about
is, if we have some clay in a
flow-through water system and we
pour our polluted sample in,
maybe these ions will actually
be attracted to the clay because
they have a different charge.
Opposites attract in this case.
What we sort of started to play
with is different types of clays
that we found in the area.
We milled them a little bit
differently.
For example, we heated this clay
up in a kiln furnace to about
800 degrees to burn off all the
organic matter, and then we
crushed it down.
As you can see here, we just
used a simple water bottle that
can be found really anywhere in
Ghana.
This is actually a 1.5-liter
water bottle.
You can find these on the
markets for maybe about one cent
or so, if there's even a charge
at all.
I poked some holes in the bottom
and lined it with some cloth, a
few layers of regular cotton
cloth.
I put some sand in, then a layer
of clay, then another layer of
fine sand.
What we wanted to do is, we
tested a whole bunch of
different things.
We actually just sort of got to
the point where we were starting
to see some results, and so the
results I'm going to show you
are very preliminary.
I don't have any error bars on
them, however, they were
confirmed by another test method
of a laboratory in --.
So I'm fairly confident of the
results here.
However, we must keep in mind
that for the testing we were
using fairly high concentrations
of these different analytes.
It doesn't necessarily mirror
the real world, but we wanted to
sort of get an idea if this
would work at all.
In many cases, it did.
I was pleased to see that for
certain ions in solution,
cobalt, copper, etc.,
lead, we were seeing a
decrease in the amount.
We have more investigation to
figure out whether that's
actually absorbing tightly onto
the clay or whether it's a very
superficial sort of thing where
it will start to rinse off in a
few minutes.
So that work is still ongoing.
Unfortunately, I'm not part of
the work anymore, but this was
at least something that we were
happy to see.
There were some other materials
that they're currently testing.
They mine a significant amount
of bauxite in that area and
bauxite can sometimes be used as
an absorbent.
They can also use charcoal.
If you think about activated
charcoal like with our Brita
filters, this is basically,
charcoal is charred vegetation.
It definitely would not have the
capacity of something like an
activated charcoal filter that
we have, but we know that
charcoal can absorb certain
pollutants and investigation is
sort of taking place with that
as well.
I just kind of wanted to finish
up here with a few different
things.
In this talk, it was sort of
just a snapshot of work that we
did over a couple of years, and
I was actually in Ghana for six
months in 2008 and six months in
2009 working on the project.
The faculty there, and I had a
couple of graduate students who
were part of the university,
were also helping me sample and
doing these analyses and are
hopefully still continuing to
utilize the equipment that I
left.
We know that mining is causing
some changes to the environment
in and around Tarkwa.
We at this point don't know the
extent.
the mining operations have
really only been exploding in
the last 20 years and as history
tells us, long-term
environmental damage can take
decades in order to understand.
But at least, even though Ghana
is sort of in its infancy when
starting to think about
environmental concerns, they are
making progress and they are
putting money and resources from
the mining companies into
looking at environmental
concerns.
Like I said, it's still very
slow and the socioeconomic
situation in Ghana is moving
along at a fairly slow rate, but
I'm hopeful and I'm expecting
that in a few years that we'll
have moved even further forward
in thinking about the
environment.
A few sites that we studied,
Akoon, Simpa, Aboso, had levels
of some chemical indicators that
we might be able to attribute to
large scale mining.
The mercury contamination was
also sort of fuzzy.
We don't have a really good
limit of detection for what we
were looking for with our
equipment.
However, we know that mercury is
used all the time by small scale
miners.
We do know that it's getting
into the environment.
Just because we can't stick a
number on it, I'm very confident
that there are environmental
concerns when we start talking
about the mercury contamination
in this area.
More work needs to be undertaken
not only to understand sort of
the chemicals and the pollutants
that are there, but also then,
now what do we do?
Rural Ghana is a developing
country and as I said, the
infrastructure is really
lacking.
So most people do not have
indoor plumbing.
They go to the bore hole for all
of their water needs.
There's a latrine, which is
sometimes sited fairly close to
the bore hole where everybody
uses and the population is
growing significantly because of
the mining operations, so I
believe the capacity of some of
these latrines and also the
water system is being taxed.
There really has to be a lot
more work done in the
remediation aspect, and of
course, it's not going to happen
overnight and there are a lot of
things we have to consider as
far as education on how to use
some of these remediation
technologies.
They have to be very low cost.
Most of the country lives below
the poverty line of $2 per day.
And they have to be local
because transportation
infrastructure is also a
problem.
In my opinion, that's really
where the work needs to be
moving and I'm happy to say that
the materials, the equipment and
materials that I used for my
project were then donated to
UMaT for the students to
continue to use.
They have students who are
interested in environmental
concerns with mining and so I
think that more data will be
coming through soon.
I want to make sure that I
acknowledge National Science
Foundation for the funding for
this project over two years, for
the Discovery Corps
post-doctoral fellowship, the
MRSEC Center for Nanoscale
Science, which was sort of my
home department while I was at
Penn State, and they were very
helpful as far as facilitating
the administration of this
grant, and definitely, sorry,
the University of Mines and
Technology.
Let's just get back to that
real quick.
Dr. Richard Amankwah
was kind of my faculty director
when I was there.
He's now the Dean of Students
at UMaT.
Fifi Quansah is a master's
student that I worked with
very closely.
He was actually helping with
the sampling and going out
to sampling sites and this work
has become part
of his master's thesis.
So thank you very much
and I will take any questions.
( applause )