Thanvir Ahmed
Biology / IDS 9A
11/08/12
The Breakdown of Urea
Problem Statement:
How will the amount of urea in the fish tank breakdown over time?
Hypothesis:
If urea is added to a system, then it will breakdown nitrate.
Materials:
Filter
Fish food
4-9 Fish
10 gallon Fish tank
4 Test Vials
150 mL beaker
10 gallons of water
pH Test Solution 37 mL
High Range pH Test Solution 37mL
Ammonia Test Solution Bottle #1 37mL
(NH3/NH4)
Ammonia Test Solution Bottle #2 37mL
(NH3/NH4)
Nitrite Test Solution 37 mL (NO2)
Nitrate Test Solution Bottle #1 30 mL
(NO3)
Nitrate Test Solution Bottle #2 30 mL
(NO3)
Freshwater master test kit color chart
Pencil
Paper
Marker
Procedures:
1. Get fish tank and clean it.
2. Draw line 5cm from top of fish tank with marker, and label it fill line.
3. Fill fish tank with water (the water should reach the fill line.)
4. Put filter on fish tank.
5. Place fish in fish tank.
6. Feed fish with fish food.
7. Do not contaminate water by putting hands or other materials in fish tank.
8. Use 150 mL beaker to scoop up 100 mL of water from fish tank.
Procedures continued:
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Thanvir Ahmed
Biology / IDS 9A
11/08/12
9. Rinse all 4 vials with water (make sure to rinse the caps of the vials)
10. Add 5 mL of fish tank water into one vial, and test pH. To test pH add 3 drops of
testing solution from pH test solution. Cap the vial and invert several times. Use
color chart to record pH level.
11. Add 5 mL of fish tank water into one vial, and test high range pH. To test high range
pH add 5 drops of testing solution from pH test solution. Cap the vial and invert
several times. Use color chart to record pH level.
12. To decide which measurement of pH to use high range pH or just pH; if the pH
makes a weird color not listed on the color chart use high range pH, if it does not
use the pH.
13. Add 5 mL of fish tank water into one vial, and test Ammonia. To test Ammonia add
8 drops of testing solution from Ammonia test solution bottle #1 to the vial; cap the
vial and invert several times. Then add 8 drops of Ammonia test solution from
Ammonia test solution bottle #2; cap the vial and invert several times. Wait 5
minutes for color to develop. Use color chart to record the Ammonia level.
14. Add 5mL of fish tank water into one vial, and test Nitrite. To test Nitrite add 5 drops
of test solution from Nitrite test solution. Cap the vial and invert several times. Wait
five minutes for color to develop. Use color chart to record Nitrite level.
15. Add 5mL of fish tank water into one vial, and test Nitrate. To test Nitrate add 10
drops of test solution from Nitrate test solution bottle #1. Cap the vial and invert
several times. Shake Nitrate test solution bottle #2 for 30 seconds (this is a very
important part.) Next add 10 drops of test solution from Nitrate test solution bottle
#2; cap the vial and invert several times. Wait five minutes for color to develop.
Use color chart to record Nitrate level.
16. Repeat steps 6 – 15 for the next month.
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Thanvir Ahmed
Biology / IDS 9A
11/08/12
Diagram:
Figure 1. Fish Tank
There is one fish inside the fish tank, and the filter is equipped to the fish tank. The fish
tank water level is filled to the fill level, and the livestock seems healthy.
Data and Observations:
Table 1
Chemical Analysis
Date
10/1/12
10/2/12
10/4/12
10/5/12
10/8/12
10/10/12
10/13/12
10/18/12
10/19/12
10/22/12
10/24/12
10/26/12
10/29/12
10/31/12
11/2/12
pH
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.2
8.2
8.2
8.0
8.0
8.2
Temperature
°C
19
21
21
22
20
20
21
21
21
19
21
21
20
20
20
Ammonia
ppm
0.00
0.25
0.50
0.50
1.00
1.00
2.00
2.00
2.00
0.50
1.00
1.00
0.25
0.00
0.25
3
Nitrite
ppm
0.00
0.25
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.25
0.25
2.00
5.00
5.00
0.25
Nitrate
Breaths
ppm
per Minute
0
66
5
65
5
64
5
67
5
68
5
65
5
65
5
64
5
66
5
65
5
67
10
68
20
65
5
64
10
63
Thanvir Ahmed
Biology / IDS 9A
11/08/12
Data and Observations continued:
Between 10/1/12 – 10/2/12, the pH (acidity of the water) was 8.0 (which is a
pretty healthy level.) From 10/1/12 – 10/2/12 the ammonia (NH3/NH4) level went from
0.00ppm to 0.25ppm, which means the fish began producing urea (waste) which was
converted into ammonia (NH3/NH4) through bacterial activity. From days of 10/1/12 10/2/12 the level of nitrite (NO2) rose from 0ppm to 0.25ppm and that was because the
fish were producing urea (waste) which was being broken down into ammonia
(NH3/NH4) which then broke down into nitrite (NO2), and this happened through
bacterial activity. From the days of 10/1/12 – 10/2/12 the nitrate (NO3) level went from
0ppm to 5ppm, which means urea was being produced then was converted to nitrite
and then nitrate, all through bacterial activity. On the date of 10/3/12, 10/5/12, 10/6/12,
10/9/12, 10/11/12, 10/12/12, 10/14/12, 10/15/12, 10/16/12, 10/17/12, 10/20/12,
10/21/12, 10/23/12, 10/25/12, 10/27/12, 10/28/12, 10/30/12, and on 11/1/12 no
observations were made. From the dates of 10/4/12 – 10/22/12 the ammonia level rose
and fell from 0.5ppm to 2.0ppm then to 0.5ppm again. This was because there was not
as much urea being produce from 10/4/12 to 10/5/12, and then the fish died of which
added urea to the system from 10/8/12 – 10/19/12. More fish were added to the tank on
10/22/12. On 10/22/12 the ammonia was converted into nitrite through bacterial activity
that is why the nitrite level rose from 0.00ppm to 0.25ppm from 10/4/12 to 10/22/12.
The nitrate level stayed the same from 10/4/12 to 10/22/12. This happened because
not as much nitrite was being produced. On 10/22/12 the pH level rose from 8.0 to 8.2
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Thanvir Ahmed
Biology / IDS 9A
11/08/12
Data and Observations continued:
this mostly occurred because of the waste inside the fish tank. From the days of
10/24/12 – 11/2/12 the pH level went from 8.2 to 8.0 then 8.2 again. From the days of
10/24/12 – 11/2/12 the ammonia level went from 1ppm to 0.25ppm then 0ppm then
0.25ppm, this is because one fish died on 10/31/12. Another fish was added on
11/2/12. The nitrite level went from 0.25ppm to 2.00ppm, then 5.00ppm to 0.25ppm.
This was because not as much urea was being produced and because of the fish being
removed. The nitrate level went from 5ppm to 10ppm then to 20ppm, and then 5ppm to
10ppm. This was because of the fish dying and the decrease in urea production. The
fish were always healthy because the average healthy breaths per minute for a regular
gold fish are 66. The temperature on average was around 20°C.
Data Analysis and Interpretation:
2.5
Level (ppm)
2
1.5
1
Ammonia
0.5
Date
Figure 2. Ammonia (NH3/NH4)
5
11/2/2012
10/31/2012
10/29/2012
10/27/2012
10/25/2012
10/23/2012
10/21/2012
10/19/2012
10/17/2012
10/15/2012
10/13/2012
10/11/2012
10/9/2012
10/7/2012
10/5/2012
10/3/2012
10/1/2012
0
Thanvir Ahmed
Biology / IDS 9A
11/08/12
Data Analysis and Interpretation continued:
Figure 2 above shows that the ammonia level rose and then fell. This happened
because of the amount of urea being produced and broken down.
6
Level (ppm)
5
4
3
2
Nitrite
1
11/2/2012
10/31/2012
10/29/2012
10/27/2012
10/25/2012
10/23/2012
10/21/2012
10/19/2012
10/17/2012
10/15/2012
10/13/2012
10/11/2012
10/9/2012
10/7/2012
10/5/2012
10/3/2012
10/1/2012
0
Date
Figure 3. Nitrite (NO2)
Figure 3 above shows that the nitrite level rose and then fell. This occurred
because of the rise and decline of the ammonia.
6
Thanvir Ahmed
Biology / IDS 9A
11/08/12
Data Analysis and Interpretation continued:
25
20
Level (ppm)
15
10
Nitrate
5
11/2/2012
10/31/2012
10/29/2012
10/27/2012
10/25/2012
10/23/2012
10/21/2012
10/19/2012
10/17/2012
10/15/2012
10/13/2012
10/11/2012
10/9/2012
10/7/2012
10/5/2012
10/3/2012
10/1/2012
0
Date
Figure 4. Nitrate (NO3)
Figure 4 above shows that the nitrate level rose, and then continued to rise
and never really fell. This occurred because of the urea production and the ammonia
production, and also the nitrite production.
7
Thanvir Ahmed
Biology / IDS 9A
11/08/12
Data Analysis and Interpretation continued:
20
Level (ppm)
15
10
Nitrite
5
Ammonia
Nitrate
11/2/2012
10/31/2012
10/29/2012
10/27/2012
10/25/2012
10/23/2012
10/21/2012
10/19/2012
10/17/2012
10/15/2012
10/13/2012
10/11/2012
10/9/2012
10/7/2012
10/5/2012
10/3/2012
10/1/2012
0
Date
Figure 5. Chemical Analysis
Figure 5 above shows the relationship between the day of observation and the
chemical level. From this relationship it can be inferred that as the ammonia level rose
it was broken down into nitrite. An example of this is on the date of 10/2/12 were the
ammonia was 0.25ppm and the nitrite level was 0.25ppm, but the nitrite level the day
before was 0ppm, and the ammonia level was also 0ppm. So, as the ammonia level
began to raise so did the nitrite. It can also be inferred that the nitrate level is
dependent on the nitrite level. An example of this is on 10/4/12 the nitrate level was
5ppm and the nitrite level was 0ppm, but on 10/2/12 the nitrite level was 0.25ppm and
the nitrate level was 0ppm. So the nitrite broke down into nitrate. All this occurred
through bacterial activity.
8
Thanvir Ahmed
Biology / IDS 9A
11/08/12
Data Analysis and Interpretation continued:
69
68
67
66
65
64
Breaths
per
Minute
63
62
11/2/2012
10/31/20…
10/29/20…
10/27/20…
10/25/20…
10/23/20…
10/21/20…
10/19/20…
10/17/20…
10/15/20…
10/13/20…
10/9/2012
10/7/2012
10/5/2012
10/3/2012
10/1/2012
60
10/11/20…
61
Figure 6. Breaths per Minute
Figure 6 above shows that the average breaths per minute were around
60. 60 is a pretty healthy number of breaths per minute for gold fish.
Conclusion:
The data that has been gathered supports the hypothesis, so the hypothesis can
be accepted. The original hypothesis was “If urea is added to a system, then it will
breakdown nitrate.” This hypothesis was correct because after the urea was added
from the fish waste, the amount of ammonia increased, amount of nitrite increased and
the amount of nitrate increased. This happened because ammonia broke down into
nitrite which broke down into nitrate.
9
Thanvir Ahmed
Biology / IDS 9A
11/08/12
Conclusion continued:
The ammonia level began with 0ppm but then increased to 0.25ppm on 10/2/12
this happened because the fish were producing a waste product known as urea, which
was being broken down by bacteria into ammonia. As the ammonia began to raise so
did the nitrite on 10/2/12 the nitrite level rose to 0.25ppm this is because the ammonia
was being broken down into nitrite through bacterial activity. As the nitrite level rose so
did the nitrate level on 10/4/12 the nitrate level was 5ppm and the nitrite level was
0ppm, but the day before the nitrite level was 0.25ppm so the nitrite broke down into
nitrate.
The urea broke down into ammonia, which broke down into nitrite, which then
broke down into nitrate. These chemicals broke down because of bacteria. Bacteria
broke down urea into ammonia, and then nitrite and then nitrate.
The flaw with the design of this experiment was that no observations were able to
be made every day. One way to improve this experiment would be to be able to make
observations every day. If the experiment were done again making observations
everyday would improve the experiment. From the data gathered it can be concluded
that urea breaks down into nitrate.
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