1. Samantha Miller
Dr. Lynguidst
ENVE 405-01
December 9, 2016
ENVE 405 Fall Quarter WESTT Final Report: Sample Preservation and pH/Alkalinity
Introduction:
This quarter I worked with John Coyne and Aydee Melgar on the Denitrification
project. I preformed sample preservation and pH/alkalinity tests for three hours every
Friday from 11am to 2pm on these tasks. When I arrived, I would start by labeling all
samples and sample tubes. I performed the appropriate preparation for each pond and
test. It is important to filter and acidify the correct samples so that the appropriate tests
can be performed. For example, the TAN samples must be acidified before filtering,
which is unlike the other samples being acidified, because the filtering process could
volatilize some of the ammonia gas in the sample and acidifying fixes the gas and keeps
it from bubbling out. If another researcher uses a sample that was not properly prepared,
it would flaw the tests results with no suitable explanation no matter how many times it
was rerun. After I finished sample preservation, I carried out the pH/alkalinity tests on a
set of samples, using the Alkalinity Bench Method last updated January 15. The pH and
alkalinity need to be monitored because there is an optimal pH range that nitrifying
bacteria perform at and algae grow in. Alkalinity needs to be monitored to ensure the
ponds have adequate buffering capability. Performing this test is important because the
ponds have any significant change, this data will be essential to help determine the cause.
Reduced nitrifying and loss of productivity could be due to high pH, or drastic variations
in the pond’s pH over a day could be caused by low alkalinity.

2. Results:
pH Data
AlkalinityData
Table 1
Date Influent Pond 1 Pond 2 Pond 3
10/7/16 450 116.667 146.667 120
10/10/16 400 126.6667 146.666 166.667
10/12/16 340 126.6667 153.33 146.667
10/14/16 376.667 100 103.333 96.667
10/17/16 326.6667 120 146.6667 126.667
10/19/16 360 100 100 100
10/21/16 406.66667 110 136.6667 110.6667
10/24/16 360 86.66666667 146.6666667 86.66666667
10/26/16 413.3333333 86.66666667 86.66666667 80
10/28/16 316.6666667 80 103.3333333 83.33333333
10/31/16 320 73.33333333 106.6666667 73.33333333
11/2/16 353.3333333 60 86.66666667 93.33333333
11/4/16 346.6666667 73.33333333 96.66666667 90
11/7/16 333.3333333 60 86.66666667 66.66666667
11/9/16 340 53.33333333 80 60
11/11/16 393.3333333 53.33333333 80 73.33333333
11/14/16 340 60 86.66666667 60
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
pH
Date
pH Over Time
Influent Pond 1 Pond 2 Pond 3

3. 11/15/16
11/16/16 366.6666667 80 80 80
11/18/16 410 73.33333333 80 80
11/28/16 326.6666667 300 286.6666667 280
NO3 Data
Table 1
Date Influent Pond 1 Pond 2 Pond 3
10/7/16 0.367082606 24.2 18.7 19.1
10/10/16 0.411197328 24.1 17.6 19.4
10/12/16 0.331790829 22.9 17.4 19.3
10/14/16 0.331790829 28.4 27.9 23.7
10/17/16 0.340613773 22 18.7 20.4
10/19/16 0.375905551 27.2 26.1 26.2
10/21/16 0.367082606 26.4 23.9 30.3
10/23/16 0.31 29 22.1 32.7
10/26/16 0.420020273 35.1 31.1 35.1
10/28/16 1.628763654 28.6 24.8 29.3
10/31/16 0.296499051 31.9 23.8 31.3
11/4/16 0.278853163 30.6 25 34.2
11/7/16 0.45531205 35.1 29.2 35.9
11/9/16 0.164154886 37.2 30.8 33.9
11/11/16 1.937566707 34.9 32.8 35.4
11/14/16 0.270030218 39.2 34.3 40.7
5
55
105
155
205
255
305
355
405
455
505
9/28/16
9/30/16
10/2/16
10/4/16
10/6/16
10/8/16
10/10/16
10/12/16
10/14/16
10/16/16
10/18/16
10/20/16
10/22/16
10/24/16
10/26/16
10/28/16
10/30/16
11/1/16
11/3/16
11/5/16
11/7/16
11/9/16
11/11/16
11/13/16
11/15/16
11/17/16
mgCaCO3/L
Date
Alkalinity Over Time
Influent Pond 1 Pond 2 Pond 3

4. 11/16/16 0.358259662 37.83333333 34 36.66666667
11/18/16 0.261207274 39.83333333 35 37.83333333
Discussion:
The goal of the denitrification research is to prove that high-rate algae raceway
ponds can treat nitrogen levels even in the winter when not as much photosynthesis is
taking place, while also reaching high biomass productivity. Project Denitrification’s
ponds are a less costly and more environmentally friendly technique than what is
currently being used in conventional waste water treatment practices, which is why it is
so important to prove it can meet nitrogen effluent standards of less than 10mg/L. The
nitrifying process in the ponds consists of bacteria using oxygen created by the algae to
convert NH3/NH4-
+ into NO2
- and NO3
-. The NO2
- and NO3
- are then converted to N2 gas
by denitrifying bacteria in anoxic reactors. If the treatment works as it should, the total
nitrogen should be reduced to less than the standards to prevent damages to the
environment and human health. If this research can prove that this way of treating water
0
5
10
15
20
25
30
35
40
NO3(mg/L)
Date
NO3 Over Time (AM/JC era)
Influent Pond 1 Pond 2 Pond 3

5. is just as effective year-round, it would be beneficial to both the environment and
residents in California and the world.
Looking at “NO3: Table 1” carefully it is evident that on November 9, there was a
reduction in NO3. If we compare this to the “pH Over Time” graph, it is shown that there
is a very slight increase in pH around that time. The increase in pH could explain this
slight decrease in NO3 because the pH levels hindered the abilities of the bacteria and the
algae. On October 28, there was a big increase in NO3 and comparing that to the pH, it
seems that pH levels at that time were pretty constant which could have caused this.
When the pH levels are at an optimum point, NO3 should be at it’s highest levels.
Since algae grow in an optimal range of pH levels, CO2 sparging was recently
implemented into the project. On November 17, 2016, CO2 began in Pond 3. If the pH
hits 7.8, it will turn on and turn back off when the pH drops down to 7.5. Carbon dioxide
produces a weak acid when it is dissolved in water, which reacts immediately with alkalis
turning them into salts and forming carbonic acid. When carbonic acid is present in
water, it is highly reactive with ions that are responsibly for alkalinity. These ions will
react to neutralize the water. The process of CO2 sparging should increase the
productivity of the algae as well as the amount of nitrifying occurring because more algae
will be able to grow and bacteris will perform better when a proper pH range is
maintained. With the right amount of algae, the project will be successful.
On November 28, 2016, there was complete pond death and all the ponds are
acting similar to the pure influent. Since the CO2 sparging was only recently added to
Pond 3, there will be no data as to how that affects the alkalinity of the algae in the pond
until they start to grow again. As seen in “Alkalinity: Table 1” above, the alkalinity in the

6. all the ponds is almost the same as the influent pond’s alkalinity. Comparing the ponds’
alkalinity when the algae were alive to now when they’re dead shows that the biological
treatment of the bacteria and algae in the pond does use up the alkalinity, which makes
sense since the process of nitrification does create some acidic byproducts, which will
consume bicarbonate. It is unclear as to why exactly the ponds died at this time, but it
could be due to the weather change. It changed drastically around this time and there was
not as much sunlight as before.
WESTT was a really great experience for me. Being a CE major who switched
from ENVE, I knew I would miss chemistry so I’m glad I was exposed to that a bit this
quarter. Water treatment really interests me and it’s something I currently want to pursue
in a career. Although I do not intend to be doing research as my career, I appreciate the
knowledge this experience has given me. Research creates so many insights to processes
and reactions that we think to be true and it’s interesting to learn the day-to-day aspects
of these processes. I hope that my schedule will allow me to join WESTT again a
different quarter.