2004 U.S. SJWP Winners' Abstracts
Brandon Fimple
Oklahoma
2004 U.S. Stockholm Junior Water Prize Winner
Project Title: The Environmental Impact of Aluminum Sulfate and Salicylic
Acid Treated Poultry Litters on Forage Production and Watersheds
Abstract
Eutrophication resulting
from phosphate pollution is one of the most costly water quality problems in
North America today. Algae overgrowth not only affects drinking water quality,
but biologists recently discovered that chemicals released by some algae
stimulate the reproduction of zebra mussels. Agricultural practices contribute
much of the non-point sources of nitrate and phosphate pollution in surface and
ground waters. Research to develop ways of reducing phosphate pollution in
watersheds is vital due to the increasing number of confined animal feeding
operations as market animal production is fast becoming a corporate farm
venture. Large concentrations of animals produce large quantities of animal
waste that must be disposed of properly to prevent nutrient pollution in
surrounding watersheds.
This experiment combined
three years of research on allelochemicals with last year’s study of alum
treated poultry litter in an effort to find an environmentally protective
litter treatment with effective algaecide properties. Salicylic acid (SA), an
allelochemical found in the roots of birch trees, has been shown to be a very
effective algaecide when added directly to poultry litter run-off water. The
purpose of this experiment was to evaluate the effects of poultry litter
fertilizer treated with salicylic acid on forage production and run-off water
phosphate levels and to determine if Closterium algae growth in the run-off
water was adversely affected. Aluminum sulfate (alum) has been used
successfully as a litter treatment, but its effects on forage production in
phosphorus deficient soil has not been evaluated. Therefore, alum was tested in
this experiment also.
Five poultry litter
treatments – 10% and 5% salicylic acid, 10% and 5% alum, and plain litter -
were tested in each phase of the experiment. It was hypothesized that the
salicylic acid and alum litters would not adversely affect forage production
and would reduce phosphorus run-off thereby limiting algae growth.
Twenty-four test plots
were established in a phosphorus deficient fescue pasture. Fertilizers were
mixed and applied to the corresponding plots. The Control plots were not
fertilized. Forage samples were taken every 45 days, dried, and weighed. Next,
fescue sod boxes with metal spouts were constructed, and treated litter was
applied. The sod fertilized with plain litter served as a control. Eight
run-off water samples per treatment were collected and analyzed for soluble
phosphates. Five samples of run-off water from each treatment were inoculated
with Closterium algae culture. Live and dead algae cell counts were performed
on Day 1 and 7 post inoculation.
The two salicylic acid
treatments did not adversely affect fescue production as both salicylic acid
litter treatments had significantly higher yields than the control plots.
Neither salicylic acid treatment significantly lowered phosphate levels in the
run-off water; however, they did adversely affect algae growth. The data
indicated that the salicylic acid may have had a direct effect on the algae
cells rather than chemically tying up the phosphates in the litter. Overall,
the data indicated that the 10% alum treated litter was the most
effective litter treatment as it did not adversely affect forage production,
significantly reduced run-off phosphate levels and adversely affected algae
growth.
Balaji Sridhar
Colorado
2004 U.S. Stockholm Junior Water Prize Finalist
Project Title: Optimization of a Novel Process of Removing Arsenic
From Drinking Water Treatment Sludge
Abstract
The source water in many
public drinking water systems contains Arsenic (As) at levels above the U.S.
EPA regulatory limit of 10 parts per billion (ppb). The most common method to
reduce As concentration is co-precipitation in ferric hydroxide sludge. The
high As levels present in the sludge make it a toxic waste requiring special
disposal methods in toxic waste landfills. Any process that will decrease the
volume of sludge will save money and benefit the environment. Furthermore, the
upcoming 2006 regulations on As make innovation in this area vital and urgent.
The experimental
approach has been:
Removal of As from the
sludge by anion exchange (using phosphate), or by direct nitric acid elution,
which is preferred.
Commonly available
denitrifying bacteria have been used to remove nitric acid from the eluate by
converting the nitric acid into harmless nitrogen gas.
The use of sulfate
reducing bacteria (SRB) to precipitate As: the product from the denitrification
process or the selective anion elution (phosphate eluate) is fed to an SRB
reactor where sulfide anion is generated and reacts with the As and other
metals to produce an insoluble As or metal sulfide. This precipitate is removed
by filtration or centrifugation, thus greatly reducing the volume and mass of
material that requires toxic waste landfill disposal. Calculations show that
all the As from one (1) metric ton of sludge could be reduced to 200 grams of
arsenic sulfide with this process; the remaining sludge is less toxic and can
more easily be treated. The likelihood that the As will reenter the water
supply is low, even in the unfortunate event of a leak from a landfill.
Abigail
Hines
Indiana
2004 U.S. Stockholm Junior Water Prize Finalist
Project Title: A Comparison of Herbs and Bti as Larvicides on
Culex pipiens and Their Effect on Daphnia magna
Abstract
If the best way to
prevent a problem is to stop it before it starts, then the best way to control
mosquitoes would be to kill them in the larval stage. That’s exactly what a
larvicide does.
But, most of the
larvicides that are used today are not recommended for use in wetlands because
they are toxic to wildlife. There is one natural larvicide used called Bti or
Bacillus thuringiensis israelensis. Bti is a soil bacterium that the larvae
eat. It is environmentally safe for wetlands use and disintegrates in 48 hours.
Yet Bti is not without
problems. First, it’s not as effective as some of the chemicals. The Ottawa
Canada Health Dept. stated, "Bti is ineffective in mosquito breeding
grounds, such as storm sewers or sewage lagoons." Also it does not work
well in polluted waters. Since Bti is a food source, the larvae must eat it. If
there are too many other food sources as in polluted water, the mosquito larvae
may not eat it. Overdosing or high frequencies of applications of Bti has also
caused some problems and has had an impact on nontarget organisms. In addition,
a long term study done by Hershey over three years found that heavy Bti use did
cause effects on the food web in the wetlands.
The purpose of my study
was to find another natural oil or plant that would be as effective as or
better than Bti, but still be safe for the environment. I wanted it to be safe
for use in the wetlands, or if it was used in other areas and somehow leaked
into the wetlands, it wouldn’t be harmful to the wildlife. In addition, perhaps
these natural alternatives may be important in newly developing countries where
many can’t afford costly chemicals.
Four herbal oils: neem,
peppermint, marigold, and catnip were tested as larvicides. My hypothesis was
that the herbs and Bti would act as larvicides, the most effective being
peppermint, without being harmful to Daphnia magna. Daphnia are a major food
source and key link in the aquatic food chain. They are also good bioindicators
of an environment’s health.
I put thirty Culex
pipiens larvae into serial dilutions of the oils with an emulsifier, EZmulse
and they were tested at time intervals from 15min to 96hrs. Catnip and
Peppermint oil concentrations were 3.125-50ppm. Neem and Marigold
concentrations were 1ppm-8ppm. The LC50 was calculated at 24 & 48hrs.
Marigold was most toxic with LC50 at 24hrs of 3ppm and LC50 at 48hrs of 2ppm.
The order of toxicity of the oils for LC50 at 24-48hrs was
Marigold>Catnip>Peppermint. Neem oil’s LC50 was above 8ppm and was not
calculated. My hypothesis that peppermint would be most effective was wrong. In
comparison, Bti (.17gm) killed all the larvae in 24hrs.
Then I did bioassays
with thirty Daphnia in the same oil concentrations and Bti for 48hrs. The
higher the concentration of the oil, the survivorship of the Daphnia decreased.
LC50’s for each oil were lower at 24 & 48 hours than the mosquitoes. Bti
had no impact on the survivorship of the Daphnia.
The emulsifier alone had
no effect on the larvae, but in 50ppm all of the Daphnia died after 2hrs. Other
studies have reported this observation that organisms died because of the inert
substances in the larvicides. Further research should be done with this
emulsifier using aquatic species.
Even though my project
did not prove these herbal oils as effective as Bti, the need still exists for
the development of more environmentally safe larvicides .It is important to
protect our wetlands because they provide for everyone more than just a place
of recreation. The wetlands work to recharge our ground water, protect our
homes from floods and are home to one third of our threatened and endangered
species.
Elizabeth
Welsh
Minnesota
2004 Stockholm Junior Water Prize Finalist
Project Title: The Use of Barley Straw to Control Algal and
Macrophyte Growth on Wild Rice Lake (Phase IV)
Abstract
This four-year-study,
which has extensively investigated the effect of barley straw on algae, was
taken into the field for the first time in Wild Rice Lake—a shallow, 2100-acre
lake north of Duluth, Minnesota. Common pondweed covers much of this lake by
mid-summer, making fishing and boating difficult. Shallow lakes tend to be more
fertile, and often weeds and algae pose a threat (Armstrong, 2003). Macrophytes
have not overtaken Wild Rice Lake until recently, and algal levels remain low.
With road construction and failing septic tanks, Wild Rice Lake is susceptible
to possible eutrophication (Duluth News Tribune, 2003). Macrophytes and
filamentous (blue-green) algae are difficult to manage (Newman, 1997). Barley
straw applications in the United States are in the early stages of testing. This
study, once again, looks at barley straws affect on algae with the addition of
Lemna minor a common biological indicator species and common pondweed, the
macrophyte causing problems in Wild Rice Lake (Welch, 1990). There are many
ideas on how barley straw liquor controls and inhibits algal growth. It is
thought that as barley straw rots, agents such as hydrogen peroxide, phenols
and oxidized phenolics are produced (Gibson, 1990; Everall and Lees, 1996;
McComas, 2001). These chemicals seem to limit the blue-green’s ability to
up-take phosphorus (Ridge, 1996). One of the more current theories is that a
diversion of phosphate occurs via the microbial loop (McComas, 2003). Past
studies have shown that barley straw can be used to treat algal problems in a
laboratory setting, but can barley straw be applied with the same results in a
lake setting (Welsh, 2000; Welsh 2001; Welsh 2002)? The purpose of this
experiment was to determine whether barley straw treatments could control
macrophyte and possible future algal problems in Wild Rice Lake. The hypothesis
is that barley straw application will control algal and macrophyte growth. To
make the leap from a laboratory study to a field setting required more
equipment and professional guidance. To begin the experiment, twenty 20-gallon
limnocorrals were placed along the shoreline of Wild Rice Lake filled with 24
liters of undisturbed lake water. Plastic mesh bags of 240 grams of barley
straw were added into two of the four trial buckets for each trial set—five
trial sets in all. Fertilizer (0.1%) was then added into two of each set of
four trial buckets, one with barley and one without. Thirty Lemna minor and
four 14-centimeter lengths of common pondweed were added to two sets of the
five, eight buckets in all. Chlorophyll a (Welsh et al), oxygen, pH and Lemna
minor frond number were measured once a week for ten-weeks. Before and after
the ten-weeks phosphate and nitrate levels were measured. The original
hypothesis that barley straw would control algal growth was supported. Results
show that barley treatment did significantly reduce algal growth when compared
to the lake and control buckets (ANOVA p<0.001). Barley straw treatments
also significantly decreased oxygen and pH in all trial containers (ANOVA
p<0.001). The second half of the hypothesis was not supported; in that
barley straw treatments significantly increased the frond number of Lemna minor
in the limnocorrals treated with barley straw and fertilizer (ANOVA
p<0.009). Barley straw treatments had no significant affect on the
temperature of the buckets, and there was no significant difference in algal
growth between the trial treatments with and without macrophytes. Phosphorus
levels in the form of phosphate were significantly increased in the
barley/fertilizer buckets when compared to the just fertilizer buckets, the
opposite was true when nitrates were measured. This supports the idea that
barley straw treatment diminishes algae’s ability to uptake phosphate. These
higher phosphate levels could also account for the significant increase of L.
minor in only the barley/fertilizer buckets. All common pondweeds added to
macrophyte trials died by the third trial week, indicating that a better
methodology is needed to measure their growth. Barley straw applications in the
nutrient limited buckets did not significantly affect algal growth. This
suggests that in nutrient limited situations (Wild Rice Lake), the application
of barley straw is not indicated. Therefore, apply barley straw only in
nutrient rich situations, and reapply after four weeks. This study also
suggests that barley straw is not a feasible floating-leaf macrophyte control
measure. In the future, barley straw application after a eutrophic situation
has already occurred in a lake will be investigated.