WATER POLLUTION CONTROL RESEARCH SERIES 16010 DXV 11/71
The Carbon Dioxide System
and Eutrophication
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U.S. ENVIRONMENTAL PROTECTION AGENCY
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WATER POLLUTION CONTROL RESEARCH SERIES
The Water Pollution Control Research Series describes the
results and progress in the control and abatement of pollution
in our Nation's waters. They provide a- central source of
information on the research, development and demonstration
activities in the Environmental Protection Agency, through
inhouse research and grants and contracts with Federal, State,
and local agencies, research institutions, and industrial
organizations.
Inquiries pertaining to Water Pollution Control Research
Reports should be directed to the Chief, Publications Branch
(Water), Research Information Division, R&M, Environmental
Protection Agency, Washington, B.C. 20^60.
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The Carbon Dioxide System and Eutrophication
Stephen D. Morton
Philip H. Derse
Russell C. Sernau
WARF Institute, Inc.
P.O. Box 2599
Madison, Wisconsin 53701
For the
Office of Research and Monitoring
Environmental Protection Agency
Grant 16010 DXV
November, 1971
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price 75 cents
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EPA Review Notice
This report has been reviewed by the Environmental Pro-
tection Agency and approved for publication. Approval
does not signify that the contents necessarily reflect the
views and policies of the Environmental Protection Agency,
nor does mention of trade names or commercial products
constitute endorsement or recommendation for use.
11
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ABSTRACT
The objective of this research was to determine the feasibility
of eutrophication control in natural bodies of water by the control
of carbon.
Growth rates of the algae Chlorella, Microcystis, and Anabaena
were studied with respect to carbon availability. Algae can utilize
dissolved concentrations of CC>2 much lower than those from at-
mospheric equilibria. Control of algal growth by sweeping the CC>2
out by aeration with air containing very low concentrations of CO?
is difficult because of atmospheric replenishment of CC^. Bicar-
bonate is at least 50% utilized at growth rates as high as 7 mg/I/day.
Atmospheric replenishment of CO?, without any wind mixing, can
sustain growth rates of 1. 5 - 2 mg/l/day for depths of at least
1. 7 meters.
This report was submitted in fulfillment of Grant 16010 DXV under
the sponsorship of the Water Quality Office, Environmental Pro-
tection Agency.
in
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CONTENTS
Section Page
I Conclusions 1
II Recommendations ^
III Introduction 5
IV Methods 7
V Results and Discussion 9
VI Acknowledgements 21
VII References 23
VIII Publications 25
IX Appendix 27
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FIGURES
Number Page
1 Growth of Chlorella and Anabaena versus
air aeration rate 11
2 Growth of Chlorella versus aeration rate
at various CC>2 concentrations in aeration air 12
vr
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TABLES
Number Page
1 Rate of growth of Chlorella versus air
aeration rate 13
2 Growth rate of Chlorella versus CO2
concentration at aeration rate of 15
13
3 Growth rate of Anabaena versus CC>2
concentration at aeration rate of 15 14
4 Growth rate of Microcystis versus CO2
concentration at aeration rate of 15 14
5 Rate of growth of Anabaena versus air
aeration rate 15
6 Growth of Chlorella with sodium bicar-
bonate as sole carbon source 16
7 Growth of Anabaena and Microcystis in
ASM Medium with sodium bicarbonate
as sole carbon source 16
8 Rate of growth of Chlorella in vessels
open to the atmosphere 18
Vll
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SECTION I
CONCLUSIONS
1) Algae can efficiently utilize carbon dioxide at concentrations
much lower than those present from atmospheric equilibria. It
is very difficult to control growth by carbon dioxide control in
systems open to the atmosphere, even when the carbon dioxide
is swept out by aeration with air containing very low concentra-
tions of carbon dioxide.
2) Bicarbonate is a good source of carbon and is at least 50%
utilized at growth rates of at least 5 mg/l/d. Many lakes can
have massive algal blooms using naturally present bicarbonate
as the sole carbon source.
3) The atmosphere, without any vigorous wind mixing, is an
adequate source of carbon dioxide for depths of at least 1. 7
meters, permitting algal growth rates of up to 2 mg/l/d.
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SECTION II
RECOMMENDATIONS
Much research is presently being done on nutrient limitation, such
as with phosphorus and nitrogen, to limit algal growth. In addition
to this, research is needed on ways to control the type of predom-
inating algal species so that the troublesome blue-greens would be
replaced by the less troublesome green algae. Though carbon is
not likely to be limiting in most bodies of water, there is evidence
that factors such as the ratios of various essential nutrients, in-
cluding carbon, and physical conditions, can regulate the type of
predominating algae, even though the total algal biomass may re-
main the same.
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SECTION in
INTRODUCTION
The role of carbon in eutrophication has been mentioned numerous
times over the years (Birge and Juday, 1911; King, 1970). Although
it is probably generally agreed that carbon may be limiting for very
high algal concentrations, such as in sewage lagoons (Bartsch and
Allum, 1957), much controversy exists as to whether carbon may
be limiting in eutrophic lakes where the algae concentrations, and
therefore carbon needs, are much less. Kerr, Paris and Brockway,
1970; Lange, 1967; and Kuentzel, 1969, claim that bacterial oxida-
tion of organics is necessary to provide the carbon necessary for
algal blooms. Wright and Mills, 1967, found carbon to be some-
what limiting in their productivity studies on the Madison River.
This research was originally undertaken to determine whether
eutrophication in small areas could be controlled by sweeping
the carbon dioxide out of the water with low carbon dioxide air
aeration. This would only be a slight modification of aeration
methods that are currently being used to improve water quality
in lakes and reservoirs (Symons, 1969; Wirth and Dunst, 1966).
A related question arises, namely, is carbon ever limiting in
natural bodies of water? Since an algal bloom.is of the order of
8 mg/1 of algae (dry weight), and grows at most perhaps 2 mg/I/day,
about 1 mg/I/day of carbon or about 4 mg/1/day of carbon dioxide
are needed. This is the crux of the phosphorus versus carbon limit-
ing nutrient question, that is whether atmospheric replenishment
of carbon dioxide is rapid enough to permit algal blooms to occur
or whether some other carbon source is needed.
Three major areas were studied. The first was the steady state,
in which the growth rates of algae at various constant, maintained
dissolved carbon dioxide concentrations were determined. These
concentrations were those in equilibrium with atmospheric carbon
dioxide concentrations and below, in contrast to much algae growth
studies which use 1-5% enriched carbon dioxide air. The second
was the non-equilibrium case where natural atmospheric replenishment
was the sole carbon source. The third was the growth of algae with
inorganic bicarbonate as the sole carbon source.
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SECTION IV
METHODS
The algae used were Chlorella pyrenoidosa, Microcystis aeruginosa,
and Anabaena circinalis. Allen's medium (Allen, 1952) was used
for Chlorella, and ASM medium (McLachlan and Gorham, 1961)
for Microcystis and Anabaena, and some of the Chlorella experi-
ments as noted. Neither of these media contain any inorganic or
organic carbon. Allen's medium contains 178 ppm nitrogen and
45 ppm phosphorus, while the corresponding values for ASM are
14 ppm and 3. 1 ppm.
Growth was followed by spectrophotometric measurements at
600 mp. using a Bausch and Lomb Spectronic 20 with 12 mm diam-
eter sample tubes. Dry weight measurements using 0.45 micron
membrane filters were also made as a check on the absorbance
measurements. An absorbance of 0. 010 was equivalent to 6 mg/1
dry weight for all three algae, and was linear over the concen-
tration range of 3-20 mg/1 reported here. A Beckman Model G
pH Meter was used for pH measurements. All experiments were
conducted indoors under continual fluorescent lighting of 90-120
foot candles and repeated three to five times, except as noted.
In the steady state experiments, air containing known quantities
of carbon dioxide (15-340 ppm range) was bubbled through the al-
gal suspensions at various flow rates, and the rate of growth de-
termined. In this type of experiment the dissolved carbon dioxide
concentration is governed by Henry's Law. This method has the
advantage of not being dependent on inadequate and inaccurate
methods for measuring the aqueous carbon dioxide at low concen-
trations. Various carbon dioxide concentrations were obtained
by mixing air (340 ppm) and low carbon dioxide (15 ppm) air to-
gether in various ratios using flowmeters. Carbon dioxide was re-
moved from air by bubbling through 2 N-NaOH. The air was lab-
oratory air pumped with small aquarium air pumps. The usual
supplies of compressed air were not used because of the possi-
bility of contamination with dirt, metal oxide flakes and oil and
grease. A Beckman GC-2 gas chromatograph with a thermal con-
ductivity detector was used for measuring the carbon dioxide
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concentrations in the various air streams. The column was packed
with 80-100 mesh silica gel. The column and detector temperatures
were 170ฐ C. Helium was the carrier gas. The instrument was
standardized using analytical quality gases of known carbon di-
oxide concentrations. Most experiments were carried out in one-
liter flasks containing 600 ml of algal suspension. The flasks
were stoppered; a small tube in the stopper permitted the aera-
tion air to escape and minimized the contact of atmospheric air
with the algal suspension which would have upset the dissolved
carbon dioxide equilibrium.
In the bicarbonate work, sodium bicarbonate was the sole carbon
source. The carbon dioxide was first swept out of the suspension
for at least two days by aeration with low carbon dioxide air, the
bicarbonate added and the flask stoppered, and the growth as a
function of time and the final equilibrium total growth were measured.
In the non-equilibrium experiments, though some smaller vessels
were used, most of the work used 6 foot (1. 8 m) high by 1 foot
(0.31 m) in diameter plexiglas cylinders that were open to the
atmosphere. A fluorescent light parallel to the side provided
constant illumination of 250 foot-candles along the entire length
of the cylinder.
The work was done in a laboratory which was originally designed
for animal studies. The ventilation system brings in three-quarters
outside air and recirculates one-quarter of the inside air. The air
is changed a minimum of every twenty minutes. Gas chromato-
graphic measurements showed the carbon dioxide concentration of
the laboratory air was the same as the outside air.
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SECTION V
RESULTS AND DISCUSSION
Most of the experiments, where possible, were carried through
an algal concentration of at least 100 mg/1. Occasionally in the
later growth stages of an experiment, some, apparently inor-
ganic, precipitation occurred. No data taken when precipitation
was occurring are included. Various unseeded control experi-
ments were run using Allen's and ASM media in which the pH
and bicarbonate concentrations were varied. No precipitation
occurred in the pH ranges of interest in this work.
The original raw data are given in the Appendix while the calcu-
lated, summary data are given in this section. In some areas
where limited experimental work was done, a few general con-
clusions are given only. Some other data are not included as they are
very similar to other data in the tables.
All growth rates given are average growth rates over their re-
spective algal concentration ranges. In all tables and figures, the
aeration rate is the ratio of the volume of air per hour to the
volume of algal suspension.
Equilibrium or steady state -- The goals were to, one, obtain
basic data that other experiments could be compared with, and
two, obtain preliminary data to show whether eutrophication
could be controlled by low carbon dioxide aeration. The raw
data are shown in Tables 9 through 30 in the Appendix. The cal-
culated, summary data are shown in Figures 1 and 2 and Tables 1
through 5 in this part of the report.
Figure 1 shows the rate of growth for Chlorella and Anabaena
as a function of the amount of air aeration. The rates level out
after a certain aeration rate is reached. These growth rates,
15 mg/l/d for Chlorella and 7 mg/l/day for Anabaena, can be
looked at as the rates of growth for maximum wind mixing under
these conditions. Microcystis data, not shown, gave a maximum
growth rate of 11 mg/l/day. Notice that Tables 1 through 5 have
Cav/Cused ratios, the theoretically available carbon provided by
the carbon dioxide in the aeration air to the carbon that the algae
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actually used in their growth. The tables also have higher algal con-
centration data while the figures show only the lower 3-20 mg/1 range
applicable to lake situations. For Chlorella, C /C , decreased
from 8. 3 at the highest aeration rate to one at the steep part of the
curve. For Anabaena, it did not decrease to one due to the slower
growth which needed a smaller rate of carbon supply.
Figure 2 shows the growth rate of Chlorella as a function of the aer-
ation rate and of the carbon dioxide concentration in the aeration
air. As expected it is dependent on both. The C /C _, ratios,
not shown in the tables but readily calculated from the figure,
were about 1. 5 throughout the aeration range where the curves
are not flat. This shows the algae are very adept at utilizing
very low concentrations of carbon dioxide, that is, no "minimum"
concentration of carbon dioxide is necessary for algal uptake.
The practical implications of this are apparent. To control eutro-
phication in a small area of s. lake by aeration with low carbon
dioxide air would necessitate using a low aeration rate. But a
high aeration rate is needed to keep atmospheric replenishment of
carbon dioxide from taking place. This will provide enough carbon
dioxide for algal growth, unless the carbon dioxide concentration
in the aeration air is actually zero, a difficult task on a large scale.
This is what was found in swimming pool and other experiments
that were open to the atmosphere. We have had no significant
success in controlling algal growth with aeration with low carbon
dioxide air, unless the atmosphere over the algae was also controlled.
Bicarbonate -- The raw data are shown in Tables 31 through 45 in
the Appendix, while the calculated, summary data are shown in
Tables 6 and 7 in this section. As the amount of bicarbonate
increases, the fraction utilized decreases. This is reasonable since
as bicarbonate is converted to carbon dioxide the pH rises; 50% conver-
sion corresponds to conversion to carbonate and a pH of near 11,
which we observed. Full conversion to carbon dioxide would pro-
duce sodium hydroxide, causing a very high pH that the algae could
not tolerate. Jolliffe and Tregunna, 1970, working with marine
algae, sea water, and low bicarbonate concentrations, found that
the slow down in the growth rate as growth proceeds is more due
to bicarbonate limitation than to the high pH. Tables 6 gives Chlorella
results for both Allen's and ASM media. The difference in buffering
capacities of these media may explain the different final pH's.
Though we generally observed a higher growth rate in the middle
stages than in the earlier stages of growth, it is clear that as bi-
carbonate is converted to carbonate, the growth slows. Table 7
indicates Microcystis to be somewhat better than Anabaena in
10
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30Mg/L CONCENTRATION RANGE
CHLORELLA
5 10 15
AERATION RATE
20
Figure 1. Growth of Chlprella and Anabaena versus air
aeration rate -- volume air per hour to volume algal suspension.
11
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O)
O
DC
O
20 r CHLORELLA
10-30 Mg/L CONCENTRATION RANGE
X
O
P 15
10
340 PPM CO.
180
80
20
5 10 15
AERATION RATE
20
Figure 2. Growth of Chlorella versus aeration rate
at various CO? concentrations in aeration air. Aeration rat'
is volume air per hour to volume algal suspension.
12
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Table 1. Rate of growth of Chlorella versus air aeration rate
Concentration range
10 - 30 mg/1 60 - 150 mg/1
Aeration Rate C /C (?) Rate C 1C (
rated) mg/l/d aV used mg/l/d av Used
20.0 -- -- 42 4.0
15.0 15 8.3 42 3.0
12.0 15 6.7 30 3.3
10.0 -- -- 36 2.3
9.0 15 5.0 34 2.2
6.0 16 3.2 24 2.1
5.0 -- -- 18 2.3
3.0 16 1.5 10 2.6
3.0 18 1.4 12 2.1
2.5 15 1.4 15 1.4
2.25 12 1.5 16 1.2
1.5 15 0.87
1.5 12 1.1 8 1.6
0.75 9 0.70
0.375 4 0.76
(1) Volume air per hour/volume algal suspension.
(2) Carbon in aeration air/carbon used by algal growth
Table 2. Growth rate of Chlorella versus CCK concentration
at aeration rate of 15
Concentration range
10 - 30 mg/1 60 - 150 mg/1
CC>2 concentration
ppm
344
180
111
81
56
45
31
Rate
mg/l/d
15
13
--
9
9
6
2
C 1C ,
av used
8.3
5.3
--
2.8
2.2
2.7
Rate
mg/l/d
42
30
19
21
9
--
a-V used
3.0
2. 1
2. 1
1.4
2.2
13
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Table 3. Growth rate of Anabaena versus CO? concentration
at aeration rate of
15
tj
Concentration range
10
CCK concentration Rate
ppm mg/l/d
344
180
111
81
56
45
31
Table 4.
6
7
8
5
5
6
5
- 30 mg/1
Cav/Cused
21
8.9
5.3
5.6
4. 1
2. 7
2.3
Growth rate of Microcystis versus
60 -
Rate
mg/l/d
22
18
18
9
9
8
150 mg/1
C /C
av' used
5.6
3.5
2.3
3.3
2.2
1.9
CO-, concentration
at aeration rate of 15
Concentration range
10 -
COo concentration Rate
ppm mg/l/d
344
180
111
81
56
45
31
10
>6
>6
>6
>6
7
5
30 mg/1
C 1C
av used
11
--
--
2.3
2. 3
60 -
Rate
mg/l/d
33
30
27
19
12
10
__
150 mg/1
Cav/Cused
3.8
2. 1
1.5
1.5
1.7
1.6
--
14
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Table 5. Rate of growth of Anabaena versus air aeration rate
Concentration range
_ 10 - 30 mg/1 _ 60 - 150 mg/1
Aeration Rate Cav/Cused Rate Cav/
rate mg/l/d _ mg/l/d
20.0 7 23 8 19
10.0 7 12 8 11
5.0 5 8 11 4
2.5 549 2.4
utilizing bicarbonate. In another experiment, successive additions of
various amounts of bicarbonate, all to total 100 ppm of bicarbonate
carbon after two weeks, were added to Allen's medium that had been
seeded with Chlorella. The total growth was the same in all cases.
For example, 100 ppm added initially had the same final effect as
ten daily 10 ppm additions.
Many lakes with calcium carbonate containing sediments, have 10-40
ppm bicarbonate carbon. Since an algal bloom is about 8 mg/1, only
about 8 mg/1 of bicarbonate carbon is needed if 50% is utilized. The
rates of growth we obtained are quite high, averaging around 4 mg/l/d,
certainly higher than usually seen in eutrophic lakes.
This is in direct and startling disagreement with Kuentzel who claimed
that algae cannot use bicarbonate at any appreciable rate, and is in
general agreement with Guyomarch and Villeret, 1965, who found
bicarbonate to stimulate growth when carbon dioxide concentrations
were low.
Non-equilibrium -- Except under conditions of extreme wind mixing
in shallow lakes, lakes are not necessarily in equilibrium with re-
spect to the sediments, water, and atmosphere (Morton and Lee,
1968). Two questions are apparent. One, what is the rate of at-
mospheric carbon dioxide replenishment, with no stirring or mixing,
for depths greater than the typical laboratory glassware? The
second is, how well is bicarbonate utilized when the water is open
to the atmosphere containing 0. 034% carbon dioxide, in comparison
to a closed atmosphere over a bicarbonate solution which can theo-
retically permit a higher gaseous carbon dioxide concentration?
15
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Table 6. Growth of Chlorella with sodium bicarbonate as sole
carbon source
Bicarbonate-C Total growth Growth rate^1) %C Final
mg/1 mg/1 mg/l/d used pH
A
B
A
B
A
B
A
B
A - Allen
B - ASM
* \Aver aง
Table 7.
10
10
25
25
50
50
100
100
's Medium
Medium
;e rate over 3
23
16
42
24
48
42
60
72
-20 mg/1 algal
4
3
6
3
7
4
10
8
100
80
84
48
48
42
30
36
i
8.5
10. 1
8.7
10.4
8.7
10.6
8.9
10. 7
concentration range.
Growth of Anabaena and Micro cystis in ASM
with sodium
Bicarbonate-C
mg/1
An
M
An
M
An
M
An
M
An
M
5
5
10
10
25
25
50
50
100
100
bicarbonate as
Total growth
mg/1
9
9
11
15
27
36
48
60
72
126
Medium
sole carbon source
Growth rate
mg/l/d
1
2
2
3
4
5
6
7
6
7
% C
used
90
90
55
75
54
72
48
60
36
62
Final
_TT
10.5
10.6
10.4
10.8
10.7
10.8
10. 8
10. 9
10.5
10. 8
An - Anabaena
M - Microcystis
(1) Average rate over 3-20 mg/1 algal concentration range
16
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The 6 ft (1.8 m) high by 1 ft (0. 31 m) in diameter open plexiglass
cylinders were used in this phase of the research.
Algal growth experiments were conducted to determine whether
bacterial degradation of the plexiglass could provide significant
amounts of carbon dioxide. No differences between the experi-
ments with and without plexiglass were seen.
The Allen's medium in the cylinders was initially equilibrated by
bubbling air through overnight before being seeded with Chlorella.
The algal suspensions were stirred for 2 minutes once a day before
sampling. To determine whether this stirring may have caused a
significant amount of carbon dioxide to go into solution two checks
were made. One cylinder was stirred the usual way and another
let grow for a week without disturbance. Both grew at the same
rate. Another check was that no change in pH could be detected
before and after stirring. In some experiments air was blown
across the top ("top air ventilation") of the algal suspensions.
There was not enough wind to cause any noticeable water move-
ment or waves. Data in this section for "no mixing" should be
interpreted as for no air movement or just very gentle air move-
ment over the surface of the algal suspension. A few of the bottom,
bubble aeration experiments were not quantitative regarding aer-
ation rates. This is noted in the tables by the absence of any
given aeration rate.
The raw data are given in Tables 46 through 53 in the Appendix
while the calculated summary data are shown in Table 8 in this
section. The algae grew at a surprisingly rapid rate of about
1.5-2 mg/l/d in the 3-15 mg/1 algal concentration range. Much of
the time the growth was unsteady. This growth rate is an aver-
age value of all experiments and is also quite conservative, as we
often observed faster rates. With 20 ppm bicarbonate carbon, also
open to the atmosphere, the rate increased to about 7 mg/l/d. The
pH's during growth were 7. 9 with no bicarbonate, and 8. 3-8. 8 with
bicarbonate. One of the cylinders had a stopcock at the bottom
which facilitated bottom sampling. The pH's at the top and bot-
tom were the same in all phases of the various experiments. The
pH's of the bottom aeration cylinders were lower, as expected,
because of the atmospheric carbon dioxide in the aeration air. Con-
siderable amounts of data, not given, for Chlorella, Microcystis,
and Anabaena, in shallower vessels of 0. 15-0.31 m depth, open to
the atmosphere, showed growth rates of 3-7 mg/I/day with no bi-
17
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carbonate and 4-9 mg/l/d with bicarbonate present. For any given ex-
periment, the bicarbonate growth rate was always higher.
It is not realistic with experiments that are open to the atmosphere
to concern ourselves with the percent utilization of bicarbonate
carbon, since it will re-equilibrate with the atmospheric or respir-
atory carbon dioxide and revert to bicarbonate. Thus it becomes a
kinetic question of bicarbonate utilization versus atmospheric or
respiratory replenishment.
The rates observed for depths up to 5.5 ft (1.7m), about 1.5-2 mg/l/d
without bicarbonate and 7 mg/l/d with, are all greater than seen
in eutrophic lakes. King, 1970, feels that bicarbonate and respira-
tory carbon dioxide are the major sources of photo synthetic carbon,
and that atmospheric carbon dioxide is minor. Our data shows that
atmospheric replenishment of carbon dioxide provides a sufficient
supply for algal blooms, for at least 5. 5 ft (1. 7 m) of depth and
no mixing. No mixing does not mean that the rate of carbon di-
oxide supply is controlled by true molecular diffusion. The algae
themselves cause some mixing by their occasional up and down
movements that we observed at numerous times, and furthermore,
small scale eddy currents are undoubtedly present.
Table 8. Rate of growth of Chlorella in vessels open to the
atmosphere
Depth No bicarbonate 20 ppm bicarbonate-C
meters mg/l/d mg/l/d
0.31 3 6
0.93 2
1.5 1.5-2 7
1.7 1.5-2 7
Average rate over 3-15 mg/1 algal concentration range
No mixing or stirring except when sampled
These experiments were conducted under rather ideal growth condi-
tions, with the idea that if atmospheric replenishment is sufficient
to permit a high growth rate, it is even more likely to be sufficient
under lake conditions where the algae grow slower needing a lower
rate of carbon dioxide supply, and where there is usually some
wind mixing.
18
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Other areas of study -- A few experiments using 16 liter jugs were
conducted to determine whether air blown over the top of an algal
suspension would speed up growth compared to the algal suspension
being open to a calm atmosphere. No differences were seen, even
with Cav/Cuge(j ratios as high as ten. This gives evidence that
calm air provides as much useable carbon dioxide as does a gentle
wind that does not cause waves or mixing. Growth rates for Chlorella
were about 4 mg/l/d for one-foot of depth.
Bottom bubble aeration or mixing will, of course, speed up growth
in deep vessels; for shallow vessels such as typical laboratory glass-
ware, it makes little difference. In our 16-liter jug experiments
(Tables 54, 55 in the Appendix), the rates of growth in the low (5-
20 mg/1) algal concentration range were similar for bubbled and
non-aerated open vessels. In the high concentration range (>60 mg/1),
the bubbled grew about twice as fast as the non-mixed.
Some data for bottom aeration, top air ventilation, and cotton stop-
pered flasks are shown in Tables 56 through 61 in the Appendix.
These data, though not relevant in lake situations, are useful in
interpreting laboratory work. The bottom aeration flow rates are
not quantitative, but are in great excess regarding the carbon dioxide
needs of the growing algae. Growth rates were similar for top
aeration and for the cotton stoppered flasks, and were often similar
for bottom aeration in half or less full 250 ml, 500 ml, and 1000 ml
erlenmeyer flasks in the lower algal concentration ranges.
Other experiments, also using laboratory sized glassware, were
done using intermittent aeration. Here the algae were aerated for
a specified time and then the flask was stoppered until the next
aeration. These data are shown in Tables 62 through 65 in the Ap-
pendix. Generally, for 20 minute aeration periods once a day
and once every 3 days, Cav/Cuse(j was approximately equal to one.
For 14, 21, and 40 day intervals, C-av/^used was somewhat less
than one, reflecting a small amount of leakage of air into the flasks,
probably during sampling. Another group of experiments (Tables
66 and 67) used 1, 4, and 8 hour aeration daily. The rates of growth
and total amounts of growth were often similar for all three cases.
Also, for the blue-green algae, continuous aeration and one hour
daily aeration often gave similar growth. It is interesting to spec-
ulate from these data, whether continual wind mixing in a lake would
permit more algal growth than just occasional wind mixing.
19
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The fraction of dissolved bicarbonate that can be used by algae is de-
pendent on the buffer capacity of the media or lake. This is because
as the buffer capacity increases, more hydroxide ion can be accepted
by the solution without the pH becoming too high for algal growth.
This will permit a greater conversion of bicarbonate and carbonate
to carbon dioxide. Some experiments were conducted using Chlorella
in ASM medium with the phosphate replaced by a phosphate buffer.
For varying amounts of buffer, 7-65 ppm or 5-45 ppm as phosphate,
the percent bicarbonate carbon utilized was 60-100% for 10 ppm car-
bon, 40-80% for 20 ppm carboi, and 40-60% for 40 ppm carbon. The
final pH's were all between 10. 1 and 10. 5. Since lake waters gen-
erally have low buffer capacities, we think that in most lakes, the
utilization of bicarbonate is about 50%, corresponding to conversion
to carbonate with a final pH of 10-11.
20
-------
SECTION VI
ACKNOWLEDGEMENTS
We thank Dr. George Fitzgerald of the University of Wisconsin,
a consultant on this project, for helpful discussions and for pro-
viding the algae samples.
The support by the Water Quality Office, Environmental Protection
Agency, and the interest and cooperation of Dr. Charles Powers,
the Grant Project Officer, and other personnel at the Corvallis,
Oregon laboratory are hereby acknowledged.
21
-------
SECTION VII
REFERENCES
1. Allen, M. B. 1952. The cultivation of Myxophyceae. Arch.
Mikrobiol. 17: 34-53.
2. Bartsch, A. F. andM.O. Allum. 1957. Biological factors
in treatment of raw sewage in artificial ponds. Limnol.
Oceanog. 2: 77-84.
3. Birge, E. A. and C. Juday. 1911. The Inland Lakes of Wiscon-
sin. The dissolved gases of water and their biological signifi-
cance. Wis. Geol. Nat. Hist. Surv. Bull. 22: 259 p.
4. Guyomarch, C. and S. Villeret. 1965. Effects of dissolved
carbon dioxide and of bicarbonate solutions on the growth of
Chlorella vulgaris. Bull. Soc. Sci. Bretagne 40: 193-206.
5. Jolliffe, E.A. and E. B. Tregunna. 1970. Studies on bicar-
bonate ion uptake during photosynthesis in benthic marine
algae. Phycologia 9: 293-303.
6. Kerr, P. C. , D. F. Paris, and D. L. Brockway. 1970. The
interrelation of carbon and phosphorus in regulating hetero-
phic and autotrophic populations in aquatic ecosystems. U. S.
Dept. Interior, FWQA Series 16050 FGS 07/70. 53 p.
7. King, D. L. 1970. The role of carbon in eutrophication. J.
Water PoHut. C0nt. Fed. 42:2035-2051.
8. Kuentzel, L. E. 1969. Bacteria, carbon dioxide, and algal
blooms. J. Water Pollut. Cont. Fed. 41: 1737-1747.
9. Lange, W. 1967. Effect of carbohydrates on the symbiotic
growth of planktonic blue-green algae with bacteria. Nature
215: 1277-1278.
10. McLachlan, J. and P. R. Gorham. 1961. Growth of Microcystis
aeruginosa in a precipitate free medium buffered with tris. Can.
J. Microbiol. 7: 869-882.
23
-------
11. Morton, S. D. and G. F. Lee. 1968. Calcium carbonate equil-
ibria in lakes. J. Chem. Ed. 45:511-513.
12. Morton, S. D. and G. F. Lee. 1968. Calcium carbonate equl-
ibria in the oceans - ion pair formation. J. Chem. Ed. 45:
513-515.
13. Symons, J. M. (Editor). 1969. Water quality behavior in
reservoirs. Part III. U. S. Dept. Health, Education, and
Welfare, Public Health Service publication 1930. 587 p.
14. Wirth, T. L. and R. C. Dunst. 1966. Limnological changes
resulting from artificial destratification and aeration of an im-
poundment. 28th Midwest Fish and Wildlife Conference,
Chicago, Illinois. 22 p.
15. Wright, J. C. and I. K. Mills. 1967. Productivity studies on
the Madison River, Yellowstone National Park. Limnol.
Oceanog. 12: 568-577.
24
-------
SECTION VIII
PUBLICATIONS
1) Morton, S. D. , Sernau, R. C. , and Derse, P. H. "Carbon and
Eutrophication". Presented at the Water Pollution Control
Federation Conference in Boston, Massachusetts, October
5, 1971.
2) Morton, S. D. , Sernau, R. C. , and Derse, P. H. "Natural Car-
bon Sources and Rate of Replenishment in Lakes". Presented
at the American Society of Limnology and Oceanography Sym-
posium on "The Limiting Nutrient Controversy", W. K. Kellogg
Biological Station, Michigan State University, Feb. 12, 1971.
3) Morton, S. D. , Sernau, R. C. , and Derse, P. H. "Natural Car-
bon Sources and Algal Growth". Presented at the American
Chemical Society Meeting, Washington, D. C. , September 14,
1971.
4) Morton, S. D. , Sernau, R. C., and Derse, P.H. "Natural Car-
bon Sources, Rates of Replenishment, and Algal Growth".
Accepted for publication, Limnology and Oceanography,
Symposium Issue, late 1971 or early 1972.
25
-------
SECTION IX
APPENDIX
Page
Growth of Chlorella versus CO concentration,
Tables 9-17 28-33
Growth of Chlorella versus aeration rate, Tables 18-21 34-35
Growth of Microcystis versus CC>2 concentration,
Tables 22-25 36-39
Growth of Anabaena versus CO concentration,
Tables 26-29 40-43
Growth of Anabaena versus aeration rate, Table 30 44
Growth with NaHCOg as sole carbon source,
Tables 31-45 45-58
Growth of Chlorella in six by one foot open cylinders,
Tables 46-53 59-62
Growth versus bottom, top, and cotton plug aeration,
Tables 54-61 63-69
Growth with intermittent aeration, Tables 62-67 70-72
27
-------
Table 9. Growth of Chlorella under steady state CO? concentrations
Aeration
Growth time
0 days
6
7
8
9
12
13
14
16
19
0
5
6
7
10
11
Table 10. Growth
rate of 15
Concentration of
Air -344 ppm
0. 0010
0. 125
0. 170
0.230
0.260
0.365
0.380
0.420
0.460
0.500
0.0013
0.010
0.012
0. 026
0. 130
0.200
u
CO2 in aeration air
180 ppm
Optical density
0.0010
0. 080
0. 130
0. 175
0. 195
0.320
0.350
0.390
0.450
0.520
0.0013
0.010
0.012
0.032
0. 115
0. 175
of Chlorella under steady state CO 2
15 ppm
0.0010
0.015
0.015
0.018
0.015
0.050
0.040
0.055
0.060
0.075
0.0013
0.002
0.002
0.002
0.005
0.008
concentrations
Aeration rate of 15
Concentration of CO2 in aeration
Growth time
0 days
6
7
8
9
1Z
13
14
16
19
Air -344 ppm
0.0010
0. 115
0. 180
0.250
0.300
0.500
0.550
0.600
0. 700
0. 800
111 ppm
Optical density
0.0010
0.080
0. 115
0. 155
0. 180
0.270
0.305
0.330
0.360
0.430
air
15 ppm
0.0010
0.005
0.020
0.025
0.020
0.045
0.050
0.050
--
--
28
-------
Table 11. Growth of Chlorella under steady state CO^ concentrations.
Aeration
Growth time
0 days
5
6
7
8
9
12
13
14
15
16
19
20
21
rate of 15.
Concentration of
Air -344 ppm
t
CCK in aeration
81 ppm
r^
air
15 ppm
Optical density
0.0008
0.025
0.035
0.075
0. 132
0.240
0.375
0.410
0.510
0.570
0.630
0. 720
0. 750
0.800
Table 12. Growth of Chlorella tinder
Aeration
Growth time
0 days
4
7
9
11
12
13
14
15
16
17
18
22
23
rate of 15.
Concentration of
Air-344 ppm
0.0008
0.019
0.019
0.040
0.055
0. 080
0. 152
0.200
0.225
0.225
0.290
0.350
0.375
0.390
0. 0008
0.009
0.009
0.010
0.009
0. 010
0. 020
0.030
0.035
0. 050
0. 060
0.075
0.085
0.090
steady state CO? concentrations
CCK in aeration
56 ppm
air
15 ppm
Optical density
0.0027
0.045
0. 190
0.330
0.410
0.440
0.46
0.47
0.48
0.48
0.48
0.48
0.46
0.48
0.0027
0.020
0. 068
0. 090
0. 120
0. 120
0. 140
0. 160
0. 18
0. 19
0.20
0.23
0.27
0.30
0.0027
0. 005
0.015
0.018
0.019
0.022
0.035
0.030
0.030
0.040
0.040
0.050
0.060
29
-------
Table 13. Growth of Chlorella under steady state CO? concentrations
Aeration rate of 15.
Concentration of CO2
Air -344 ppm
Growth time Optical
0 days
5
6
7
8
12
13
14
15
18
Table 14.
0.0010
0.070
0. 125
0. 180
0.220
0.355
0.385
0.400
0.430
0.490
in aeration
45 ppm
density
0.0010
0.020
0. 030
0.050
0. 050
0.075
0.095
0.095
0. 105
0. 130
Growth of Chlorella under steady state CO
Aeration rate of 15.
Concentration of CO2
Air -344 ppm
Growth time Optical
0 days
4
7
9
11
12
13
14
15
16
17
18
22
23
0.0027
0.040
0.220
0.350
0.43
0.44
0.43
0.48
0.49
0.49
0.49
0.50
0.50
0.50
ฃ
air
15 ppm
0.0010
0.005
0.010
0.015
0.015
0.015
0.025
0. 020
0.020
0.023
2 concentrations
in aeration air
31 ppm
density
0.0027
0.010
0. 020
0.021
0. 034
0.038
0.040
0. 048
0.050
0.050
0. 065
0. 070
0. 100
0. 105
15 ppm
0.0027
0.010
0.015
0.015
0.023
0.025
0.021
0.025
0.025
0.035
0.030
0.030
0.045
0.045
30
-------
Table 15. Growth of Chlorella under steady state CCK concentrations.
Aeration rate of 5.
Concentration of CC>2 in aeration air
Air-344 ppm 180 ppm 111 ppm 81 ppm 56 ppm
Average of
4 experiments
Growth time
OptJo-al density
0 days
3
4
7
8
0.007
0.070
0. 15
0.29
0.30
0.007
0.045
0.070
0. 14
0. 16
0.007
0.050
0.070
0. 12
0. 15
0.007
0.040
0.060
0. 11
0. 13
0.007
0.040
0.050
0.080
0. 10
Air-344 ppm
Average of
2 experiments
0 days
4
5
6
7
8
11
12
0.001
0.037
0.090
0. 15
0. 19
--
--
_ _
45 ppm 35 ppm 15 ppm
0. 001
0.030
0.040
0.040
0.055
0.060
0.085
0.095
0.001
0.020
0.030
0.030
0.040
0.040
0.060
0.060
0. 001
0.010
0. 012
0.010
0.015
0.015
0.020
0.020
31
-------
Table 16. Growth of Chlorella under steady state CO? concentrations.
Aeration rate of 3.
Concentration of CC>2 in aeration air
Air-344 ppm 180 ppm 111 ppm 81 ppm 56 ppm 15 ppm
Average of
4 experiments
Growth time Optical density
0 days
4
6
7
8
11
0.001
0.015
0.090
0. 17
0.25
0.001
0.015
0.055
0.070
0.090
0. 12
0.001
0.010
0.045
0.060
0.060
0.070
0.001
0.005
0.020
0. 030
0.040
0.055
0.001
0.005
0.030
0.040
0.045
0.060
0.001
0.005
0.007
0.009
0.017
0.015
Air-344 ppm
Average of
2 experiments
0 days
4
5
6
7
8
11
0.001
0. 075
0. 14
0. 18
0.23
0.26
--
45 ppm 35 ppm 15 ppm
0.001
0.040
0.001 0.001
0.025
0. 025
0.030
0.035
0. 020
0. 025
0.025
0.030
0.030
0.015
0.015
0:015
0.015
0.020
0.040 0.025
32
-------
Table 17. Growth of Chlorella under steady state
Aeration rate of 0. 75.
concentrations.
Growth time
. .
Concentration of CO? in aeration air
Air-344 ppm 180 ppm 111 ppm 81 ppm 56 ppm 15 ppm
Average of
4 experiments
Optical density
0-1 days
3
4
6
7
11
14
17
0.010
0.050
0.080
0. 14
0. 17
0.27
--
0.010
0.030
0.045
0.060
0.065
0.070
0.085
0. 10
0.010
0.035
0.035
0.045
0.045
--
0. 050
0.065
0.010
0.025
0.035
0.040
0.045
0.045
0.060
0.070
0.010
0.030
0.035
0.040
0.040
--
0.010
0.015
0.020
0.020
0.020
--
--
Air-344 ppm
Average of
2 experiments
45 ppm 35 ppm 15 ppm
0 days
2
5
6
7
8
9
12
0.001
0.010
0.035
0.050
0.080
0. 11
0. 15
0.21
0.001
0.005
0.010
0.015
0.020
--
0.020
0.020
0.001
0.001
--
0.015
--
0.015
0.015
0.020
0.001
0.005
0.015
--
--
--
--
--
33
-------
Table 18. Growth of Chlorella versus air aeration rate
Optical Density
Aeration rate
Growth time 3.0 1.5 0.75 0.375
0 days
4
7
8
9
10
11
14
15
16
17
0.001
0. 010
0.030
0. 060
0.080
0. 115
0. 140
0.210
0.240
--
0.001
0.010
0.035
0.055
0. 075
0.090
0. 110
0. 140
--
0.001
0.010
0.030
0. 045
0. 060
0. 060
0.080
0. 100
0. 105
0. 11
0. 001
0. 010
0. 030
0.035
0.050
0.050
0.055
0.065
0. 065
0.070
0.075
Table 19. Growth of Chlorella versus air aeration rate
Optical Density
Aeration rate
Growth time 12.0 6.0 3.0 1.5
0 days
4
5
6
7
8
11
12
13
0.001
0.015
0. 030
0. 060
0. 11
0. 18
0.30
0.31
0.35
0. 001
0.015
0.030
0. 070
0. 11
0. 16
0.25
0.29
0.32
0.001
0.015
0. 040
0.070
0.090
0. 12
0. 17
0. 19
0.20
0.001
0.015
0.030
0.060
0.065
0. 080
0. 11
0. 12
0. 13
34
-------
Table 20. Growth of Chlorella versus air aeration rate
Optical Density
Aeration rate
Growth time
0 days
6
7
8
9
12
20.0
0.001
0. 13
0.21
0.27
0.37
10.0
0.001
0.08
0. 15
0.21
0.28
0.36
Table 21. Growth of Chlorella versus air
Growth time
0 days
2
3
4
7
8
9
10
20. 0
0.003
0.012
0.030
0.090
0.23
0.27
0.29
0.31
Optical Density
Aeration rate
10.0
0. 003
0. 008
0.018
0. 070
0.22
0.27
0.31
0.34
5.0
0.001
0.06
0. 11
0. 15
0.20
0.29
aeration
5.0
0. 003
0.010
0.023
0.075
0.20
0.24
0.28
0.31
2.5
0.001
0. 045
0.07
0. 09
0. 13
0. 19
rate
2.5
0.003
0. 008
0.019
0.060
0. 14
0. 16
0.20
0.21
35
-------
Table 22. Growth of Microcystis under steady state CO-, concentra-
tions. Aeration rate of 15.
Growth time
0 days
7
8
9
10
11
14
0
7
8
9
10
11
14
Concentration of CO7 in aeration air
L*
Air-344 ppm 180 ppm
Optical density
0.0080
0.075
0. 105
0. 145
0.215
0.325
0.450
Air-344 ppm
0.0080
0. 080
0. 115
0. 155
0.245
0.310
0.450
0. 0080
0.075
0. 115
0. 150
0.210
0.280
0.460
111 ppm
0.0080
0. 080
0. 120
0. 160
0.215
0.260
0.350
15 ppm
0.0080
0.015
0. 035
0.020
0.030
0.040
15 ppm
0.0080
0.015
0.030
0.030
0.030
0.030
36
-------
Table 23. Growth of Microcystis under steady state CO? concen-
trations. Aeration rate of 15.
Concentration of CCK in aeration air
15 ppm
Growth time
0 days
7
8
9
10
11
14
15
16
17
0
7
8
9
10
11
14
15
16
17
Air-344 ppm 81 ppm
Optical density
0.0080
0.075
0. 100
0. 120
0. 190
0.250
0.400
0.440
0.500
0.550
Air -344 ppm
0.0080
0. 110
0. 155
0.210
0.260
0.335
0.500
0.525
0.560
0.600
0.0080
0.090
0. 125
0. 160
0.200
0.230
0.310
0.330
0.350
0.380
56 ppm
0. 0080
0. 085
0. 110
0. 125
0. 160
0. 180
0.230
0.240
0.280
0.300
0.0080
0. 030
0. 030
0. 035
0.050
0.060
0. 060
0.060
0.070
0.070
15 ppm
0.0080
0.010
0.020
0.015
0.020
0.020
0. 020
0.030
0. 040
37
-------
Table 24. Growth of Microcystis under steady state CC>2 concen-
trations. Aeration rate of 15.
Concentration of CC>2 in aeration air
Air-344 ppm 45 ppm 15 ppm
Optical density
Growth time
0 days
4
5
6
8
10
11
12
13
14
0
4
5
6
8
10
11
12
13
14
0. 0080
0.020
0.040
0.050
0. 13
0.27
0.34
0.44
0.45
0.50
Air -344 ppm
0.0080
0.030
0.050
0.070
0. 18
0.34
0.42
0.49
0.54
0.59
0.0080
0.035
0. 050
0.060
0.088
0.11
0. 12
0. 14
0. 17
0. 18
3 1 ppm
0.0080
0. 030
0. 040
0. 045
0.065
0.085
0. 100
0. 100
0. 12
0. 14
0.0080
0.020
0.023
0.020
0.030
0. 035
0.045
0.040
0.045
0.045
15 ppm
0.0080
0.030
0.040
0.045
0.060
0.075
0. 070
0.075
0.090
0.090
38
-------
Table 25. Growth of Microcystis under steady state CO? concen-
trations. Aeration rate of 0. 75.
Concentration of CO? in aeration air
Air-344 ppm 56 ppm 35 ppm 15 ppm
Growth time Optical density
0 days
7
8
9
10
13
14
15
16
17
20
0.005
0. 015
0.019
0. 022
0. 035
0.065
0. 075
0.080
0.085
0.090
0. 12
0.005
0. 015
0. 015
0.015
0.015
0.023
0.023
0.027
--
0.028
0.030
0. 005
0.015
0.015
0.018
0.018
0.020
0.020
0. 022
--
0.024
0.005
0.015
0. 015
0.015
0.015
0.015
0.015
0.015
0.015
0.015
0.020
39
-------
Table 26. Growth of Anabaena under steady state CO2 concentrations.
Aeration rate of 15.
Growth time
0 days
3
4
5
6
7
10
11
12
13
14
0
3
4
5
6
7
10
11
12
13
14
Concentration of CO? in aeration air
Air-344 ppm 180 ppm 15 ppm
Optical density
0.0070
0.015
0.015
0.015
0.015
0. 025
0. 030
0. 030
0. 030
0.030
0.030
15 ppm
0.0070
0.010
0. 020
0.020
0.025
0.040
0.060
0.060
0. 060
0. 060
0. 0070
0.025
0. 025
0.050
0.045
0.060
0. 130
0. 160
0. 190
0.210
0.250
Air -344 ppm
0.0070
0.010
0.030
0. 055
0.075
0. 120
0.260
0.320
0.350
0.380
0.430
0.0070
0. 020
0. 030
0.035
0. 055
0.085
0. 175
0.220
0.240
0.250
0.300
111 ppm
0.0070
0.010
0.025
0.030
0.050
0. 080
0. 180
0.200
0.220
0.250
0.260
40
-------
Table 27. Growth of Anabaena under steady state CO-, concentrations.
Aeration rate of 15.
Growth time
0 days
4
7
10
11
14
17
18
19
20
21
0
7
9
10
11
15
16
18
21
22
25
Concentration of
in aeration air
Air-344 ppm 81 ppm
Optical density
0.0070
0. 030
0.055
0.085
0. 110
0.200
0.305
0.320
0.350
0.370
0.390
0.0070
0.030
0. 055
0.055
0.070
0. 110
0. 155
0.220
0.365
0.410
0.450
0. 0070
0. 030
0.050
0.088
0. 120
0. 175
0.220
0.230
0.240
0.280
0.270
0.0070
0.030
0.055
0.060
0.075
0. 140
0. 160
0. 195
0.220
0.240
0.260
15 ppm
0.0070
0. 020
0.025
0.028
0. 030
0.040
0.040
0. 045
0.050
0.0070
0. 020
0.030
0.030
0.030
0.035
0.045
0.050
0.055
0.070
41
-------
Table 28. Growth of Anabaena -under steady state CC>2 concentrations.
Aeration rate of 15.
Growth time
0 days
4
7
10
11
14
17
18
19
20
21
Concentration of CC>2 in aeration air
Air-344 ppm 56 ppm
Optical density
15 ppm
0.0070
0. 030
0. 048
0. 072
0.095
0. 190
0.310
0.320
0.350
0. 0070
0.030
0.048
0.072
0. 090
0. 120
0. 155
0. 160
0. 160
0. 185
0. 185
0. 0070
0. 020
0.020
0.022
0.025
0. 025
0. 025
0. 025
0.030
0.030
--
0
7
9
10
11
15
16
18
21
22
25
0.0070
0.030
0.040
0.060
0.070
0. 080
0. 120
0.225
0.310
0.370
0.450
0.0070
0.040
0.055
0.080
0. 090
0. 140
0. 160
0.200
0.240
0.240
0.250
42
-------
Table 29. Growth of Anabaena under steady state CC>2 concentrations.
Aeration rate of 15.
Concentratian of CC>2 in aeration air
Air-344 ppm 45 ppm
Growth time Optical Density
15 ppm
0 days
7
9
10
11
15
16
18
21
22
25
0. 0070
0.035
0. 040
0. 060
0. 060
0. 080
0. 100
0. 160
0.265
0.320
0.370
0. 007D
0. 030
0.050
0.070
0. 080
0. 125
0. 145
0. 180
0.210
0.220
0.225
0. 0070
0. 020
0. 025
0.040
0. 040
0.040
0.045
0. 055
0. 065
--
Air-344 ppm
31 ppm
15 ppm
0
7
9
10
1]
15
16
18
21
0.0070
0. 025
0. 050
0.050
0. 050
0. 100
0. 130
0.220
0.320
0. 0070
0.030
0. 050
0. 050
0. 060
0. 080
0. 100
0. 110
0. 115
0.0070
0.015
0.020
0.025
0. 030
0. 025
0. 030
0.035
43
-------
Table 30. Growth of Anabaena versus air aeration rate.
Optical density
Aeration rate
Growth time 20.0 10.0 5-0 2.5
0 days
4
5
6
7
8
11
12
13
15
18
19
0.003
0. 015
0. 025
0.030
0.040
0.060
0. 11
0. 13
0. 16
0. 18
0. 19
0.22
0.003
0.015
0.025
0. 030
0. 045
0. 060
0. 10
0. 10
0. 11
0. 11
0. 15
0. 19
0. 003
0.015
0.025
0.030
0. 035
0. 050
0. 080
0.090
0. 11
0. 11
0. 18
0.21
0.003
0.020
0.025
0.035
0.045
0.050
0. 070
0.080
0. 080
0. 10
0. 13
0. 16
44
-------
Table 31. Growth of Chlorella in Allen's medium with NaHCO3
as sole carbon source. 600 cc algal suspension in
one-liter flask
ppm NaHCO,-C
0 (control) 50 100
Growth time Optical density
0 days
3
7
9
13
17
0.015
0.015
0.015
0. 020
0.020
NaHCO3
0. 020
0.020
0. 020
0.020
0.020
0. 020
0.015
0.030
0.090
0. 105
0.090
added again
100 ppm
cumulative
0. 10
0. 10
0. 16
0. 16
0. 16
0. 16
0.015
0.030
0. 095
0. 105
0. 105
200 ppm
cumulative
0. 12
0. 13
0.20
0.22
0.23
0.23
17
20
27
31
34
36
37 50 ppm NaHCO -C added to control
41 0.07(7
42 0.080
44 0. 10
45
-------
Table 32. Growth of Chlorella in Allen's medium with NaHCC>3 as
sole carbon source. 600 cc algal suspension in one-liter
flask.
ppm NaHCO3-C
Cotton stoppered
0 (control) 25 50 100 control
Growth time Optical density
0 days
2
5
9
12
16
0. 001
0.005
0. 015
0. 015
0.020
0.020
0.001
0. 015
0. 080
0. 070
0. 10
0. 10
0.001
0.015
0.080
0.080
0. 12
0. 13
0.001
0. 020
0.080
0.090
0. 12
0. 13
0.001
0.010
0.040
0.045
0. 11
0. 10
Same but one-liter flasks full
0 days
2
5
9
12
16
20
0.001
0.005
0.020
0.015
0.020
0.020
0.015
0.001
0.010
0.050
0.065
0.065
0.001
0.010
0.050
0.050
0.075
0.090
0.090
0. 001
0.015
0.060
0.065
0.085
0. 090
0.095
46
-------
Table 33. Growth of Chlorella in Allen's medium with NaHCO3
as sole carbon source. 600 cc algal suspension in
one-liter flask.
Growth time
0 days
4
7
11
14
0 days
4
7
11
14
ppm NaHCO3-C
0 (control) 10
Optical density, pH
25
0.
0.
0.
0.
0.
0025
010,
020,
020,
020,
7.6
8.0
8. 1
8.0
0.
0.
0.
0.
0.
0.
0.
0.
0.
0025
010,
010
020,
030
060,
055,
060,
055,
7.
8.
8.
8.
8.
8.
9
5
6
5
5
5
0.
0.
0.
0.
0.
0.
0.
0.
0.
0025
010,
015
040,
050
090,
090,
090,
080,
8.
8.
8.
8.
8.
8.
0
6
7
8
7
7
50
100
0
0
0
0
0
0
0
0
.0025
.020,
.015
.070,
. 060
.070,
.080,
--
.080,
8.
8.
8.
8.
8.
2
6
7
7
7
0.
0.
0.
0.
0.
0.
0.
0.
0.
0025
020,
040
080,
095
11,
10
11,
11
8.4
8.8
8.9
8.9
47
-------
Table 34. Growth of Chlorella in Allen's medium with NaHCC>3
as sole carbon source. 600 cc algal suspension in
one-liter flask
ppm NaHCO3 -C
Cotton stoppered
0 (control) 25 50 100 control
Growth time Optical density
0 days
2
4
7
11
15
20
0. 001
0. 010
0.010
0. 010
0.010
0.010
0.020
0. 001
0. 010
0.045
0. 090
0.090
--
0.001
0. 020
0.050
0.090
0.095
--
0.001
0.020
0.050
0. 12
0. 13
0. 14
--
0.001
0.010
0.025
0.040
0.060
0.070
0. 10
Same, but one-liter flasks full
0 days
2
4
7
11
15
20
0. 001
0. 010
0. 010
0. 015
0.020
0. 015
0,015
0. 001
0.010
0.045
0. 060
0.080
0. 085
--
0.001
0.015
0.045
0.060
--
0.070
0.070
0. 001
0.020
0.060
0.070
0. 10
0. 10
0. 10
48
-------
Table 35. Growth of Chlorella in Allen's medium with 20 ppm
NaHCOo-C as sole carbon source.
One liter algal
suspension in
four liter-flask
Two liters algal Four
suspension in liter
four liter flask flask full
Control-two
liters.: algal
suspension in
four liter flask
Growth time
0 days
3
6
8
13
15
0.001
0.030
0. 080
0. 080
0.090
Optical density
0.001
0.020
0.075
0.090
0.090
0. 001
0.020
0.050
0.060
0. 090
0.090
0.001
0. 005
0.010
0.015
0.020
0.020
49
-------
Table 36. Growth of Chlorella in ASM medium with NaHCO3 as
sole carbon source. 600 cc algal suspension in one-
liter flask.
ppm NaHCO3-C
0 (control) 5 10
Growth time Optical density, pH
0.001
0.005, 8.7
0.013, 9.5
0.012, 9.2
0.015, 9.6
0.015, 9.4
0.015, 9.8
0. 020
0.020, 10.0
0.015, 9.8
0.025, 10.3
0.025, 10.3
0.025, 10.3
0.025, 10.3
0.025, 10.3
0.030, 10.3
0.030, 10.2
0.025, 10.1
0 days
7
8
9
10
11
15
18
21
23
28
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
001
003,
005,
005,
010,
005,
010
005,
010,
010,
010,
008,
010,
010,
012,
012,
010,
010,
010,
010,
7.
7.
7.
7.
7.
7.
7.
7.
8.
9.
8.
8.
8.
9.
8.
9.
8.
9.
0
2
3
2
4
4
6
9
3
0
7
8
8
1
9
3
7
2
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
001
008
010
010
015
010
015
010
015
010
018
020
020
020
020
020
020
020
^
9
9
9
9
9
9
9
9
i
9
9
9
9
9
020,
020
9
8.2
9.3
9.0
9.5
9.3
9.8
10,
10.
10.
10.
10.
10.
10.
10.
10.
10.
0
2
2
2
2
2
1
0
0
0
50
-------
Table 36 (continued).
Growth time
ppm NaHCO3-C
25 50
Optical density, pH
100
0 days
7
8
9
10
11
15
18
21
23
28
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
001
010,
005,
015,
015,
018,
015,
015,
020
020,
020,
030,
030,
038,
040,
042,
045,
040,
050,
040,
045,
8.9
8.8
9.2
9.1
9.3
9.2
9.3
9.5
9.5
9.8
10.
10.
10.
10.
10.
10.
10.
10.
10.
1
2
3
5
4
3
3
3
3
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
D.
001
012,
010,
020,
020,
025,
020,
025,
030
030,
025
047,
050,
065,
070,
075,
080,
090,
075,
--
075,
8.8
8.8
9. 1
9.0
9.2
9. 1
9.3
9.5
9.8
10.
10.
10.
10.
10.
10.
10.
--
10.
0
2
3
6
6
4
4
-
5
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
001
015,
015,
030,
025,
040,
030,
045,
040
055,
040,
085,
080,
11,
11,
13,
13,
14,
14,
14,
13,
8. 7
8.6
9.0
8.9
9.1
9.0
9.3
9.5
9.3
9.9
9.8
10.2
10.2
10.5
10. 5
10.4
10.4
10. 7
10. 7
51
-------
Table 37. Growth of Chlorella in ASM medium with NaHCO3 as
sole carbon source, 300 cc algal suspension in
500 cc flasks.
ppm NaHCO^-C
0 (control) 5 10
Growth time Optical density? pH
0 days 0.002 0.002 0. 002
6 0.010, 7.4 0.020, 9.4 0.020, 9.45
0.010 0.020 0.020
10 0.010, 8.0 0.025, 10.2 0.040, 10.2
0.012 0.030 0.045
13 0.020, 8.3 0.030, 10.2 0.040, 10.3
0.015 0.025 0.045
17 0.015, 8.8 0.030, 10.2 0..045, 10.4
0.015, 7.9 0.030 0.040, 10.3
20 0.015, 9.4 -- 0.045, 10.3
0.015, 8.6
25 50 100
0 0.002 0.002 0.002
6 0.030, 9.6 0.025, 9.4 0.055, 9.6
0.025 0.030 0.045
10 0.055, 10.3 0.050, 9.8 0.12, 10.0
0. 050 0. 070 0. 080
13 0.055, 10.4 0,070, 10.1 0.14, 10.3
0.050 0.085 0.14
17 0.055, 10.5 0.090, 10.8 0.17, 10.8
0.050 0.085, 10.5 0.14, 10.6
20 --- 0.090, 10. 8 0. 16, 10. 7
0.085, 10. 5 0. 16, 10. 7
52
-------
Table 38. Growth of Microcystis in ASM medium with
as sole carbon source. 600 cc algal suspension in
one-liter flasks
Growth time
ppm NaHCC>3-C
0 (control 10
Optical density
50
100
0 days
5
6
9
12
19
0. 0007
<0. 001
<0. 001
<0. 001
<0. 001
0. 010
0. 0007
0.025
0.040
0. 030
--
0. 040
0.0007
0.050
0.065
--
0. 12
0. 12
0. 0007
0.050
0.070
0. 16
0.23
0.24
Table 39. Growth of Microcystis in ASM medium with NaHCO,
as sole carbon source.
one-liter flasks
600 cc algal suspension in
Growth time
0 days
7
12
19
0. 001
0. 005
0.010
0. 010
ppm NaHCO3-C
0 (control 25
Optical density
50
100
0.001
0.025
0.045
0.040
0.001
0.030
0.095
0. 080*
0. 001
0.030
0. 125
0. 140*
0
7
12
19
Same, except flasks filled with algal suspension
0. 001
0. 010
0.010
0.001
0.005
0.045
0.040
0.001
0.010
0.075
0.085*
0. 001
0.015
0.080
0. 11*
*Algal suspension becoming cloudy and discolored.
53
-------
carbon source. 600 cc algal suspension in one liter fl
ppm NaHCO3-C
0 (control) 5 10
Growth time Optical density , pH
0 days
9
12
16
19
21
0.
0.
0.
0.
0.
0.
002
005,
010,
015,
020,
020,
7.0
7.5
9.0
10.5
10.2
25
0 days
9
12
16
19
? i
0.
0.
0.
0.
0.
0.
0.
0.
002
012,
015
030,
025
080,
095
070,
__*
8.2
9.1
10.3
10.8*
0.
0.
0.
0.
0.
0.
0.
0.
0.
-
002
008,
010
010,
010
020,
020
030,
040,
_*
7.4
7.8
9.4
10. 6
10. 7
5 0
0.
0.
0.
0.
0.
0.
0.
0.
0.
002
010,
015
020,
030
075,
12
16,
17
__*
8.2
8.8
9.7
11. 0
0.
0.
0.
0.
0.
0.
0.
0.
0.
002
010,
010
020,
010
045,
030
050,
045,
__*
7.
9.
10
10
10
9
1
.4
.8
. 7
100
0.
0.
0.
0.
0.
0.
0.
0.
0.
002
010,
010
015,
020
070,
070
20,
24,
=!<
8.
8.
9.
11.
10.
2
5
3
0
4.
rAlgal suspension becoming cloudy and discolored.
54
-------
Table 41. Growth of Microcystis in ASM medium with NaHCC>3 as
sole carbon source. One-liter flasks completely filled
with algal suspension
Growth time
0 (control
0 days
4
7
10
14
0. 008
0. 010
0. 020
0.020
0.020
ppm NaHCO -C
10
Optical density
50
100
0.008
0.045
0. 040
0.040
0.008
0. 060
0. 10
0. 13
0. 13
0.008
0. 050
0. 95
0. 14
0.21
Table 42. Growth of Anabaena in ASM medium with NaHCC>3 as
sole carbon source. 600 cc algal suspension in one-
liter flasks
0 (control)
Growth time
ppm NaHCC>3-C
10
Optical density
50
100
0 days
7
10
14
17
0.0005
0. 005
0. 010
0.010
0. 010
0.0005
0.010
0.035
0.035
0.030
0.0005
0.025
0. 070
0. 10
0. 090
0.0005
0.015
0.070
0. 12
0. 13
55
-------
Table 43. Growth of Anabaena in ASM medium with NaHCO, as
sole carbon source. 600 cc algal suspension in one-
liter flasks
ppm NaHCO3-C
0 (control) 10 25 50 100
Growth time Optical density
0 days
6
8
16
20
23
26
Same
0
6
8
16
20
23
26
0. 005
0. 015
0. 015
0. 015
0. 020
0.020
0. 020
except one -liter
0. 005
0. 015
0. 015
0.015
0.015
0.020
0.020
0.005
0. 020
0.040
0. 040
*
*
*
flasks filled with algal
0.005
0.015
0.020
--
0.020
0. 030
0.040
0.005
0.015
0.020
0.020
0. 050
0.055
0.055
0.005
0.015
0.020
0. 030
0.075
0. 11
0. 12
suspension
0.005
0.015
0.020
0.025
0.080
0. 10
0. 12
0.005
0. 020
0.040
Q. 060
0.085
0. 14
0. 18
0.005
0.015
0.020
0.040
0.090
0. 15
0, 17
Note: Discoloration developed after 26 days in all flasks
#Discolo ration
56
-------
Table 44. Growth of Anabaena in ASM medium with NaHCO^ as sole
carbon source
Growth time
0 days
3
7
9
15
17
Same
0 days
3
7
9
15
17
0 {control)
0.003
0.020
0.020
0.020
0. 020
-
600 cc algal suspension in one -liter flask;
ppm NaHCO3-C
10 25
Optical density
0.003 0.003
0.025 0.025
0.040 0.050
0.050 0.075
* *
* *
50
0.003
0. 025
0.050
0. 11
0. 11
0. 10*
100
0.003
0.025
0.045
0. 11
0. 14
0. 13*
except flasks filled with algal suspension
0.003
0. 020
0.025
0.025
--
0. 020
0.003 0.003
0. 030 *
0. 035 *
*
0. 050 *
0. 045* *
0. 003
0.015
0.030
0. 030
0.090
0. 090*
0.003
0.020
0.030
0.045
0.090
*
*Discolored and cloudy
57
-------
Table 45. Growth of Anabaena in ASM medium with NaHCCU as sole
carbon source. 600 cc algal suspension in one-liter flasks.
Growth time
0 days
9
12
16
19
21
22
23
26
0 days
9
12
16
19
21
22
23
26
ppm NaHCO3-C
0 (control 5
Optical density, pH
0.003
0. 003, 7. 1
0.010, 7.6
0.020, 10.0
0.020, 9.9
0.015, 10.0
0.018, 10.2
0.018, 10. 1
0. 020, 10. 1
0.003
0.005, 7.5
0.010, 9. 1
0.020, 10.2
0.035, 10.5
0.035, 10.4
0.040, 10.7
0.040, 10.5
0. 040, 10. 5
50
0.003
0.005, 8. 1
0.010, 8.6
0.010
0.035, 9.3
0.035
0.050, 9.9
0.070, 10.0
0.055, 10.0
0. 080, 10.4
0.075, 10.4
0. 10, 10.8
*
0. 11, 11. 0
*
*
25
0.003
0.005,
0.015,
0.040,
0.060,
*
*
-i*
*
100
0.003
0. 010,
0.025,
0.010
0.060,
0.030
0. 11,
0.050,
0. 14,
0. 070,
0. 16,
0. 10,
0. 16,
0. 11,
8.2
9.0
9.8
10. 7
8.4
8.8
9.4
10. 1
9.5
10.2
9. 7
10.7
10. 0
10.8
10. 0
*
*Discoloration and cloudiness
58
-------
Table 46. Growth of Chlorella in non-mixed six foot by one foot
cylinder open to the atmosphere. Algal suspension
three feet deep.
Growth time Optical density
0 days 0.001
3 0.005
4 0.010
5 0.020
6 0.020
8 0.025
9 0. 040
10 0.040
Table 47. Growth of Chlorella in six foot by one foot cylinders open
to the atmosphere. Algal suspension five feet deep.
Optical density > pH
Growth time
0 days
2
3
5
6
7
8
9
10
13
15
16
20
21
22
No mixing
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
001
003,
005,
009
015,
018
022,
030,
035,
045,
060,
060,
073,
071,
070,
7.
7.
7,
7.
7.
7.
7.
7.
7.
7.
7.
7.
5
4
35
6
6
5
6
6
5
5
5
5
Bottom air
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
001
003,
005,
009
010,
Oil
015,
020,
030,
030,
060
060,
070,
--
080,
7.
7.
7.
7.
7.
7.
7.
7.
7.
7.
mixed
5
3
3
3
3
4
4
4
2
2
59
-------
Table 48. Growth of Chlorella in six foot by one foot cylinders open
to the atmosphere. Algal suspension five feet deep.
Optical density, pH
Growth time
0 days
4
5
6
7
8
11
12
13
14
15
18
19
20
21
22
25
Table 49. Growth of Chlorella in six foot by one foot cylinders open
to the atmosphere. Algal suspension five feet deep. Com-
parison of frequent stirring and weekly stirring.
Optical density, pH
Growth time Frequent sampling' Weekly sampling*
0 days 0.001 0. 001
6 0.020, 7.6 0.018,7.6
7 0.025, 7.9
8 0.025, 7.9
9 0.028, 7.9
10 0.030, 7.9
13 0.030, 7.8 0.035, 7.8
15 0.035, 7.8
20 0. 050, 7.8 0.055, 7.8
No
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
mixing Bottom
001
012,
015,
025,
030,
035,
030,
032,
040,
045,
055,
055
058
060
070
7.
7.
7.
7.
7.
7.
7.
7.
7.
7.
2
4
6
6
7
8
8
8
7
7
0.
0.
0.
0.
0.
0.
0.
o:
0.
0.
0.
0.
0.
0.
0.
air mixed at 1. 5 I/minute
001
012,
015,
020,
020,
030,
032,
040,
045,
050,
055,
065,
068,
--
095,
105,
7.
7.
7.
7.
7.
7.
7.
7.
7.
7.
7.
7.
7.
7.
2
4
5
4
5
6
5
5
4
4
4
4
5
4
^'Stirred only at time of sampling.
60
-------
Table 50. Growth of Chlorella in six foot by one foot cylinders open
to the atmosphere. Algal suspension five feet deep.
Optical density, pH
Same, but 20 ppm
Growth time No mixing NaHCO^-C present
0 days 0.002 0. 002
3 0.005 0.005
4 0.010, 7.7 0.012, 7.8
5 0.020, 7.7 0.027, 8.0
6 0.027, 7.8 0.045, 8.2
7 0.027, 7.9 0.055, 8.5
8 0.032, 7.9
9 0.041, 7.9
11 0.048, 7.8
12 0.053, 7.8
Table 51. Growth of Chlorella in six foot by one foot cylinders
open to the atmosphere. Algal suspension five and
one-half feet deep.
Optical density, pH
Top air No mixing, 20 ppm
ventilation, NaHCO3-C added
Growth time No mixing 2 1/minute at 5 days
0 days 0.003 0.003 0. 003
5 0.012, 7.5 0.010, 7.5 0.009, 7.7
6 0.018, 7.7 0.020, 7.8 0.015, 8.1
7 0.022, 8.0 0.040, 8.2 0.029, 8.5
8 0.028, 8.2 0.053, 8.2 0.055, 8.7
61
-------
Table 52. Growth of Chlorella in six foot by one foot cylinders open
to the atmosphere. Algal suspension five and one-half
feet deep.
Optical density, pH
Top air ventilation,
Growth time No mixing 2 I/minute
0 days 0. 002 0. 002
3 0.008, 7.4 0. 008, 7.3
4 0.012, 7.6 0.018, 7.5
5 0.015, 7.8 0. 023, 7.8
6 0.018, 7.8 0.031, 7.8
7 0.020, 7.9 0.040, 7.9
8 0.022, 7.8 0.040, 7.9
10 0.025, 7.8 0.043, 7.8
Table 53. Growth of Chlorella in six foot by one foot cylinders open
to the atmosphere. Algal suspension five and one-half
feet deep.
Optical density, p_H
Same but 20 ppm NaHCC>3
Growth time No mixing added at 5 days
0 days 0. 002 0. 002
2 0.010 0.010
5 -- 0.021, 7.8
6 -- 0.043, 8.4
7 0.040, 7.8 0.065, 8.6
8 0.043, 7.8 0.075, 8.6
62
-------
Table 54. Comparison of growth of Chlorella for bottom (344 and
15 ppm CO2) and top aeration in full 16 liter jugs open
to atmosphere.
Bottom-344 ppm Bottom-15 ppm Top
Growth time Optical density
0 days 0.001 0. 001 0. 001
1 0.005 0.005 0.005
6 0.010 0.010 0.025
7 0.015 0.015 0.025
8 0.020 0.015 0.030
9 0.030 0.015 0.040
10 0.030 0.015 0.040
13 0.045 0.025 0.055
14 0.060 0.030 0.060
21 0.11 0.060 0.070
23 0.12 0.080 0.080
Table 55. Comparison of growth for bottom and top aeration in full 16
liter jugs open to atmosphere.
Bottom Top
Growth time Optical density
Chlorella
0 days 0.001 0.001
2 0.005 0.005
3 0.005 0.010
4 0.005 0.010
7 0.015 0.030
8 0.025 0.040
10 0.040 0.050
18 0. 13 0.070
21 0.17 0.085
25 0.17 0.10
Microcystis
0 days 0.001 0.001
4 0.005 0.005
21 0.010 0.005
28 0.020 0.015
38 0.100 0.080
63
-------
Table 55 (continued).
Bottom Top
Growth time Optical density
Anabaena
0 days 0.001 0.001
4 0.010 0.010
13 0.020 0.015
24 0.015 0.035
28 0.020 0.060
38 0.070 0.100
Table 56. Comparison of Chlorella growth for bottom (bubble)
aeration , top aeration, and cotton plug aeration for
different volumes of algal suspensions.
Bottom Top Cotton plug
250 cc in one-liter flask
Growth time Optical density
0 days 0. 007 0. 007 0.007
4 0.25 0.10 0.12
5 0.28 0.14 0.14
6 0.32 0.17 0.17
7 0.35 0.19 0.20
8 0.36 0.25 0.23
600 cc in one-liter flask
0 0.007 0.007 0.007
4 0.23 0.080 0.080
5 0.28 0.095 0.090
6 0.33 0.10 0.10
7 0.35 0.13 0.12
8 -- 0.13 0.12
One liter flask full
0 0.007 0.007 0.007
4 0.22 0.060 0.070
5
6
7 0.35 0.090 0.080
8 0.39 0.080
64
0.007
0.22
0.27
0.32
0.35
0.39
0. 007
0. 060
0.065
0.070
0.090
-------
Table 57. Comparison of Microcystis growth for bottom (bubble)
aeration, top aeration, and cotton plug aeration for
different volumes of algal suspensions.
Bottom Top Cotton plug
250 cc in one-liter flask
Growth time Optical density
0 days
6
7
9
10
13
14
0
6
7
9
10
13
14
0
6
7
9
10
13
14
15
0.007
0. 10
0. 18
0.35
0.48
0.55
0.55
600
0.007
0.070
0. 11
0.24
0.35
0.53
0.58
0.007
0.040
0. 070
0. 14
0.23
0.42
0.48
0. 007
0. 070
0.095
0. 17
0.24
0.34
0.38
cc in one -liter flask
0.007
0.050
0.070
0. 14
0. 19
0.29
0.34
One- liter flask
0.007
0.080
0. 12
0.25
0.32
0.46
0.54
0.58
0.007
0. 030
0.030
0. 040
0.060
0. 070
--
0.085
0.007
0. 050
0. 070
0. 11
0. 16
0.21
0.25
full
0.007
0. 020
0.030
0.030
0.050
0. 050
0.060
0.060
65
-------
Table 58. Comparison of Anabaena growth for bottom (bubble)
aeration, top aeration, and cotton plug aeration for
different volumes of algal suspensions.
Bottom Top Cotton plug
250 cc in one liter flask
Growth time Optical density
0 days
8
9
13
15
19
20
0
8
9
13
15
19
20
0
8
9
13
15
19
20
0.0070
0. 10
0. 13
0. 13
0. 18
0.29
0.32
600
0.0070
0.080
0. 11
0.20
0.33
0.45
--
0.0070
0.060
0.085
0. 10
0. 11
0. 12
0. 13
cc in one -liter
0. 0070
0. 050
0.055
0.080
0. 11
0. 15
--
0. 0070
No good
ti
ii
n
n
n
flask
0.0070
0. 025
0.045
0. 055
0.075
0. 12
0. 13
One -liter flask full
0.0070
0.060
0.080
0. 11
0. 19
0.27
0.30
0.0070
0.030
0.035
0.040
0.050
0.060
0.065
0. 0070
0.020
0.025
0.030
0. 040
0.040
0.040
66
-------
Table 59. Comparison of growth for bottom (bubble) aeration, top
aeration, and cotton plug aeration. All 325 cc algal
suspension in 500 cc erlenmeyer flasks.
Growth time
0 days
7
10
13
14
16
21
0
7
10
13
14
16
21
0
7
10
13
14
16
21
Bottom
Top
Optical density
Cotton plug
Chlorella
0. 0040
0. 11
0. 16
0.26
0.28
0.32
0.54
0. 0040
0.075
0. 18
0.33
0.38
0.47
0. 78
0. 0040
0.040
0.085
0.25
0.28
0.38
0.53
0.0040
0.065
0.088
0. 12
0. 12
0. 14
0. 18
Microcystis
0.0040
0.065
0. 14
0.24
0.25
0.30
0.41
Anabaena
0. 0040
0.020
0. 052
0. 10
0. 11
0. 15
0.26
0.0040
0. 060
0.088
0. 11
0. 12
0. 14
0. 18
0. 0040
0.075
0. 15
0.26
0.28
0.33
0.48
0. 0040
0.020
0.038
0.070
0. 070
0.090
0. 16
67
-------
Table 60. Comparison of growth for bottom (bubble) aeration and
cotton plug aeration. 600 cc algal suspension in one liter flasks.
Chlorella - Allen's medium
Growth time
6 days
15
21
29
37
6
15
21
29
37
15
21
29
37
Bottom
Optic _al
0.060
0.32
0.33
0.35
0.39
Chlorella
0.095
0.33
0.43
0.49
0.54
Microcystis
Bottom Cotton plug
0.030 0.010
0.070 0.025
0.21 0.060
0.33 0.15
Cotton plug
density
0.030, 0.040
0.070, 0.060
0.070, 0. 10
0. 10, 0. 12
0. 10, 0. 13
- ASM medium
0.015
0.040
0.070
0.13
0. 18
Anabaena
Bottom Cotton plug
0.060
0.13
0.16
0.24
68
-------
Table 61. Comparison of growth for bottom (bubble) aeration, top
aeration, and cotton plug aeration. All 800 cc algal
suspension in one liter erlenmeyer flasks
Bottom Top Cotton plug
Growth time Optical density
0 days
5
7
8
12
15
16
19
20
21
0
5
7
8
12
14
15
16
19
20
0
5
7
8
12
14
15
16
19
20
0. 012
0.045
0. 12
0. 16
0.24
0.33
0.33
0.36
0.42
0.42
0. 12
0.027
0.030
0.045
0. 17
0.36
0.47
0.60
--
--
0.012
0.045
0. 075
0. 11
0.23
0.52
0.60
--
--
Chlorella
0. 012
0.030
0.060
0.060
0.060
0. 090
0.090
0. 12
0. 12
0. 12
Microcystis
0.012
0.027
0. 030
0. 045
0. 11
0.21
0.24
0.29
0.39
0.39
Anabaena
0.012
0. 030
0.045
0.045
0.075
0. 12
0. 14
0. 15
0. 18
0.012
0.030
0.060
--
0.060
0. 075
0.075
0.075
0.090
0.090
0.012
0.015
0.015
0.015
0. 015
0.054
0.060
0.075
0. 11
0.11
0.012
0.045
--
0.036
0.045
0.084
0.075
0. 10
0. 10
0. 10
69
-------
Table 62. Growth of Chlorella under intermittent aeration (344 ppm
Growth time
1 week
2
3
5
6
8
1 week
2
3
5
6
8
1 week
2
3
5
6
8
1 week
2
3
5
6
8
in various media. 600 cc algal suspension
lasks.
Allen's
2 ppm
N-NO3
Medium
Allen' s
15 ppm
N-N03
Allen1 s
178 ppm
N-NO3
4. JL
in one-
ASM
1 4 ppm
N-NO3
Optical density
0.045
0.080
0. 10
0. 15
0. 18
0.22
0.040
0. 070
0. 070
0.090
0.090
0. 11
0.040
0.045
0.050
0.070
0.070
0.080
0.040
0.050
0.060
0.070
0.070
0.070
20 minutes aeration
0.050
0.090
0. 11
0. 15
0. 18
0.20
20 minutes aeration
0.020
0.065
0.070
0.090
0. 10
0. 13
20 minutes aeration
0.035
0.055
0.060
0.070
0.075
0.085
20 minutes aeration
0.030
--
--
per day
0.050
0.080
0.085
0.13
0. 15
0. 19
every 3 days
0.035
0.055
0.050
0.070
0.085
0.090
every 7 days
0. 030
0.045
0.050
0. 060
0.070
0.080
every 14 days
0. 030
0.040
0.040
0.050
0.040
0.050
0. 030
0.053
0.070
0. 10
0. 12
0. 12
0.015
0.040
0.035
0.042
0.055
0.060
0.020
0.020
0.020
0.020
0. 025
0.040
0.020
0.020
0.020
0.020
0.020
0.020
70
-------
Table 63. Growth of Chlorella under intermittent aeration
(344 ppm CO2). One-liter flasks filled with algal
suspension.
Growth
time
20 minutes
aeration
every day
20 min/
4 days
20 min/
10 days
20 min/
20 days
20 min/
40 days
Optical density
10 days
4 weeks
7 weeks
Table 64.
Growth
time
0.030
0.070
0. 130
0. 025
0.040
0.060
Growth of Microcystis
(344 ppm CO
flasks.
20 minutes
aeration
every 2 days
0.015
0.030
0.050
0. 020
0.035
0.030
0.020
0.020
0.030
under intermittent aeration
.,). 600 cc algal suspension in one -liter
20 min/
4 days
20 min/
7 days
20 min/
14 days
20 min/
21 days
Optical density
2 weeks
3
4
6
Table 65.
0.020
0.050
0.052
--
0.020
0.040
0.042
0.060
0.010
0.025
0. 025
0.030
0.010
0.025
0.025
0.025
Growth of Anabaena under intermittent aeration
0.010
0.020
--
0.020
(344 ppm
CO2). 600 cc algal suspension in one-liter flasks.
Growth
time
20 minutes
aeration
every day
20 min/
3 days
20 min/
7 days
20 min/
14 days
20 min/
21 days
Optical density
2 weeks
3
5
0.035
0.035
0.080
0.025
0.020
0.035
0.020
0.020
0.020
0.010
0.012
0.020
0.010
0. 010
0.010
71
-------
Table 66. Growth of Chlorella under intermittent aeration (344 ppm
CO2). 600 cc algal suspension in one-liter flasks.
8 hr aeration/day 4 hr/day 1 hr/day
Growth time Optical density
6 days
15
21
29
37
6
15
21
29
37
Table 67.
aeration (344 ppm CC>2). 600 cc algal suspension in
one-liter flasks.
8 hr aeration/day 4 hr/day 1 hr/day
Growth time Optical density
Allen's
0.
0.
0.
0.
0.
060,
20, 0.
27, 0
35, 0
40, 0
0.095
23
.33
.44
.50
0
0
0
0
0
medium
.070,
.17,
.23,
.29,
.31,
0;090 0
0.20 0
0.27 0
0.30 0
0.36 0
.050,
.12,
.15,
.21,
.20,
0.060
0. 12
0.19
0.22
0.24
ASM medium
0.
0.
0.
0.
0.
035
11
19
25
31
: Microcystis
0
0
0
0
0
and
.035
.080
.14
.20
.27
0
0
0
0
0
Anabaena under
.025
.040
.085
. 12
.15
intermittent
15 days
21
29
37
15
21
29
37
0.020
0.045
0.19
0.43
0.037
0.025
0.25
0.34
Microcystis
0.030
0.075
0.25
0.50
Anabaena
0.050
0.070
0.18
0.27
0.020
0.060
0. 19
0.37
0.030
0.065
0. 13
0.20
72
-------
1
Accession Number
w
5
^ Subject Field & Group
O5C
SELECTED WATER RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
Ortfซ,i,.tian WARF Institute, Inc.
Madison, Wisconsin 53701
Title
"The Carbon Dioxide System and Eutrophication"
J Q Authors)
TUnrfrnn,
------- |