This document summarizes an experiment that tested two methods for purifying water using solar disinfection. The researchers tested whether adding black tape (to accelerate heating) or aeration (to allow more oxygen absorption) was more effective at killing E. coli bacteria within 6 hours. They found that both the black tape and aeration methods reduced E. coli levels to under 100 in undiluted water and under 40 in a 1/10 dilution, demonstrating that solar disinfection through EPA Method 1604 can successfully purify water within a short time frame.

1. Authors: Kenneth Wong, Dehebie Elisee, Jasmine Lockhart
Department of Physical Sciences
EPA METHOD 1604 EXPERIMENT
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Abstract
Introduction
Materials & Methods Results
Conclusion
References
Barry University, Miami Shores, FL, 33161
In this experiment water was sterilized that was
not suitable for human consumption in less
than 6 hours. A rapid test was performed to see
how many E.coli were present in the water
before treatment through the SODIS method.
Two variables were then used to see which one
was more effective for treating the water. One
variable was black tape which was believed to
accelerate the temperature of the bottle causing
the detoxification process to speed up. The
other variable was aeration. Aeration is
believed to speed up the detoxification process
by trapping oxygen, allowing more heat to be
absorbed by the water killing the bacteria. The
water was then filtered in different
concentrations which consisted of: undiluted,
1/10 dilution and 1/100 dilution. These filters
were placed in agarose plates and incubated.
The data was recorded and observed.
In some parts of the world, the solar disinfection
of water is extremely important when it comes to
everyday life. Water is purified through EPA
METHOD 1604 AND SODIS . This method is
used in places like Kenya, Tanzania, Ethiopia,
Vietnam and some American states. Limitations
of solar heating are: a specific time, about ten
liters of water in each container and sun exposure.
More than 2 million people in 30 countries
around the world benefit from SODIS.
In conclusion, according to EPA METHOD 1604,
the appearance of blue spots also known as E.Coli
shows a positive reaction of the bacteria.
However, in this experiment, by using EPA
METHOD 1604 to purify the water through sun
exposure, it was observed that E.Coli was
completely was destroyed. Therefore, EPA
METHOD 1604 can be used as a beneficial
method to ensure the purification of water.
Niknam, A. (2012, February 2 ). Sodis: Solar Disinfection of
Water for Rural and Small Communities in Iran. Retrieved
from Solutions For Water :
http://www.solutionsforwater.org/solutions/sodis-solar-
disinfection-of-water-for-rural-and-small-communities-in-iran
Materials:
• Micro Tester Pro
• Small Glass Jar
• 100 mL Pyrex Jar
• 2100 Q Portable Turbidimeter (HACH)
• Water Metals Check (SenSafe TM
)
• 2 Bottles
• Thermometer
• 2 Plastic Containers
• 9 Agar Plates
• Water Sample
• Water Works TM- Nitrate and Nitrite Test Strips
Methods:
1.Pour water sample into a container (100mL).
2.Label the Micro Tester Pro.
3.Place Micro Tester Pro into the water sample. Rub the Micro
Tester Pro at the bottom of the container so that the tip breaks off.
Ensure that the Micro Tester Pro is filled with water.
4.Pour the water sample into a glass jar.
5.Place the Nitrate and Nitrite test strip into the water sample.
Remove the strip and let it sit for 2 minutes.
6.While waiting, place the water sample into the HACH 2100 Q
and measure the turbidity. Make sure that the lid is closed when
testing.
7.Remove the glass jar.
8.Place the water metals test strip into the glass jar.
9.Let it sit, then record the results.
10.Rinse the container that will be used.
11.Pour the water obtained from the lake and use a funnel to pour
the water into both bottles (aeration and black tape bottles). Do not
full the aeration bottle all the way to the top.
12.Label the bottles.
13.Place bottles on the grass in which direct sunlight can be
received.
14.At 30 minute intervals, check the temperature and shake well
for 4 hours.
15.Obtain 9 agar plates and label them: 3- Undiluted, 3- 1/10 and
3- 1/100.
16.Filter the undiluted water into a flask (100 mL).
17.Remove the container and take the filtered sheet out and place
it into the agar plates. Ensure that the forceps used to take the
filtered sheets out are heated as a sterilization process.
18.Incubate the agar plates and record the results after 24 hours.
Figure 1: Results from the E. Coli testing in the agar plates.
(Controls and two variables- Aeration and Black Tape)
For the undiluted samples of Aeration and the Black Tape, there were
less than100 E.Coli present. For the 1/10 Dilution for Aeration and Black
Tape there were less than 40 E.coli present. Lastly, for the 1/100 Dilution
for Aeration and Black Tape there were less than 8 E.coli present.
U.VEXPOSURE TIME
3.6 11:00
3.6 11:30
3.9 12:00
4.2 12:30
4.2 1:00
4.2 1:30
4.1 2:00
3.8 2:30
3.6 3:00
3.1 3:30