PRESERVATION OF WASTEWATER EFFLUENT SAMPLES
FOR
FORMS OF NITROGEN AND PHOSPHORUS
By
Daniel F. Krawczyk
Pacific Northwest Environmental Research Laboratory
National Environmental Research Center
Con/all is, Oregon
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CORVALLIS, OREGON 97330
Water Quality Parameters
ASTM STP573
ASTM 1975 pg 152-163
-------
i
-------
Title: Preservation of Wastewater Effluent Samples
for
Forms of Nitrogen and Phosphorus
Abstract:
Samples of water containing concentrations of total organic carbon
at levels greater than 20 mg/1 when preserved with 40 mg/1 of mercuric
chloride did not provide a complete inhibition of microbiological growth.
A complete inhibition was noted at a preservation level of 400 mg/1
of mercuric chloride.
A study was conducted on chemical changes of forms of nitrogen and
phosphorus in wastewater effluents preserved with 400 mg/1 of mercuric
chloride.
A variety of wastewater treatment plant effluent samples was combined into
one composite. The composite was then divided into ten equal samples.
Each sample was analyzed separately for Kjeldahl nitrogen, ammonia
nitrogen, nitrite nitrogen, nitrate nitrogen, orthophosphate
phosphorus and total phosphate phosphorus after 10, 30, 60, 80 and
100 days. Due to a logistical handling problem, the samples were
usually processed in order in batches. An analysis for total organic
carbon, total inorganic carbon and dissolved inorganic mercury was
conducted after 100 days.
Small but measurable differences were observed for all constituents
from one period to another. The ammonia, nitrite, nitrate nitrogen
system was most susceptible to change. The Kjeldahl nitrogen analysis
showed the greatest variation among replicates and sets.
-------
The study indicated that wastewater samples can be stored at room
temperature after preservation with 400 mg/1 of mercuric chloride
for periods of up to TOO days with only minimal changes in the form
of nitrogen and phosphorus.
IV
-------
INTRODUCTION
In conducting reruns (reanalysis) on samples preserved for analysis
with 40 mg/1 of mercuric chloride there were indications that the
40 mg/1 level was not always adequate to inhibit biological activity.
The preliminary evidence indicated that when the level of organic
material was at a 20 mg/1 organic carbon concentration, neither sulfuric
acid (.2 ml cone/liter) nor mercuric chloride (40 mg HgCl^/l) would inhibit
microbial growth. A study was conducted using samples from a local
wastewater treatment plant, a nearby creek and an effluent from a fish
hatchery. The study indicated that microbial growth (total plate
count growth at 37° and 25°C in a tryptone-glucose-yeast agar) would
occur when 0.2 ml of concentrated sulfuric acid per liter of sample
or 40 mg/1 of mercuric chloride was used as a preservative. Since no
growth was observed for 31 days (length of study) when 400 mg/1
of mercuric chloride was used, this information was not made part of
Table I. The results of the study are shown in Table J. Samples
collected were kept at room temperature during the period of this study.
Hellwig reported that 60 to 80 mg/1 of HgCl2 preserved polluted
river water for 18 days (Ref. 1). In a later study on preservation
of wastewater samples Hellwig used 890 mg/1 of mercuric chloride
to preserve the samples for 43 days (Ref. 2).
Jenkins reported that in an estuarine environment 40 mg/1 and storage
at 4°C for a maximum of eight days was a suitable preservation technique
for forms of nitrogen (Ref. 3). However, for forms of phosphorus,
Jenkins recommended use of 40 mg/1 mercuric chloride and storage
at -10°C with no observable changes in 31 days, again in an estuarine
environment (Ref. 4). Brezonik and Lee, and Howe and Holley, reported
on the preservation of forms of nitrogen using mercuric chloride
(Ref. 5 and 6). The studies by the latter investigators pointed out
-------
problems that one encounters with use of sulfuric acid as a preserving
agent. A number of studies on a variety of wastewater samples indicated
that 400 mg/1 will preserve a sample for forms of nitrogen and phosphorus
from time of collection to time of analysis. The time limit between
collection and analysis was arbitrarily chosen as seven days. Studies
at the Laboratory Services Branch and data reported by Hellwig indicated
that the time frame could be extended to 43 days (Ref. 2).
-------
EXPERIMENTAL
When wastewater treatment plant samples which have been preserved
with 400 mg/1 of mercuric chloride arrive in the laboratory they are
assigned a laboratory number designating the week of collection
and are computer scheduled for analysis. Each sample is then mixed in a
blender to provide uniform particle size for analysis of Kjeldahl nitrogen
and total phosphate. After blending, the samples are passed through
a glass fiber filter (free from organic binder) and the filtrate
is stored in borosilicate-stoppered tubes (stopper contains a teflon
coated cap) at room temperature. Ammonia nitrogen, nitrite nitrogen,
nitrate nitrogen and orthophosphate phosphorus analyses are performed
on the filtrate using automated techniques. The ammonia analysis
is performed using the indophenol blue reaction, (Ref. 7). Nitrate
is reduced to nitrite in a cadmium reduction column. This nitrite and
the nitrite in the original sample are determined using the classical
"Griess" reaction (Ref. 8). The single reagent phosphomolybdate
complex reduced by ascorbic acid and catalyzed by antimony salt
with elimination of arsenic interference is the procedure used for
orthophosphate analysis (Ref. 9 and 10).
Total phosphate phosphorus and Kjeldahl nitrogen analyses were performed
on the unfiltered sample stored at room temperature. Samples for total
phosphate were diluted 10 to 1 using a programmed diTutor and were
dispensed into 11.5 ml calibrated glass test tubes. Sulfuric acid
containing ammonium persulfate is added to the diluted sample.
The test tube is capped snugly with a teflon lined closure. The
samples are autoclaved at 132°C for 30 minutes. After cooling,
the autoclaved samples are placed into the sampling cycle and analyzed using
the orthophosphate phosphorus procedure noted above (Ref. 9 and
10). For the Kjeldahl analysis a 5 ml sample is digested with sulfuric
acid, potassium sulfate and mercuric oxide as catalysts. After
digestion the final volume is adjusted to 50 ml and the sample is
analyzed for ammonia nitrogen using the indophenol blue reaction
(Ref. 7).
3
-------
The question was asked concerning the length of time the forms of
nitrogen and phosphorus would remain unchanged after preservation with
400 mg/1 of mercuric chloride and laboratory handling procedures.
Samples of wastewater treatment plant effluents which had been preserved
with 400 mg/1 of mercuric chloride at time of collection for this study were
obtained from the Eutrophication Survey Branch and were mixed together.
The information on the samples is shown in Table II. The mixed samples
were then distributed into ten containers and were provided with
ten different laboratory numbers for run one. For each subsequent
run a different set of lab numbers was used. The samples were treated
as if they had been received as legitimate and individual samples.
The treatment of samples was so designated to remove any bias in
handling samples. Thus for each peri.od ten individual samples were
catalogued and analyzed as ten separate entities. Although the
samples all originated from one composite, the variation in the
number of replicate analyses was a function of scheduled replication
as part of the Analytical Quality Control Program.
At the end of the last group of analyses the samples were analyzed
for suspended solids, inorganic carbon, organic carbon and dissolved
mercury. The results of the analyses for these constituents are
indicated in Table III. The level of suspended solids is not typical
for wastewater effluents. The concentration of dissolved mercury in
the sample is an indication of the source of the suspended solids
assumed to be mercurous chloride and other precipitated mercurials
which precipitated either on initial mixing or through reaction as a
function of storage time.
-------
RESULTS
The data for the individual analyses are presented in Tables IV-IX. In
Table X a summary of the student T-test is presented, (Ref. 12).
Each possible combination was examined.
In the Kjeldahl determination at the 95% confidence level, differences
were observed between all runs except the first and last (Table X).
The differences could be due to changes within the samples or errors i_n_
measurement. In the judgment of the writer more credence is assigned
to the errors in measurement theory since the relative standard
deviation for the all runs category is .089 (Table IV). The value for
relative standard deviation and range compares favorably with data
reported by Winter, and Midgett, for Kjeldahl nitrogen at 4.1 and
4.61 mg/1 levels (Ref. 11). Thus, even though the T-test indicates
differences, application of judgment on complexities of the test
will permit the assessment that there has been no significant change
in the samples from the time of first analysis to the time of last
analysis. Furthermore, our normal procedure for quality control chart
production requires the use of duplicate analysis which would provide for
a greater latitude in differences. The use of ten to eleven replicates
provides an excellent means to identify errors in measurement due to
sampling techniques of analysis as well as chemical changes in samples.
If chemical changes due to storage were the cause, then a pattern would
be observed in Figure 1 showing changes in Kjeldahl similar to that
reported by Hellwig (Ref. 1). Since such changes were not observed,
the cause of difference seen in the T-test is attributed to sampling and
measurement error.
The data for ammonia analysis in Table V again require application
of judgment since the initial run data are significantly different
from any of the other runs. However, with the exception of run 2 versus
-------
run 3, there are no significant differences between the other runs.
An assumption is made that errors in measurement caused the discrepancy
in comparing run one with all others and run two with run three. In Table
V when comparing data from this study with data reported by Winter and
Midgett, using relative standard deviation, the judgment is made that
there was no change in the sample during the time period of analysis.
The nitrite nitrogen analyses have changed over time as indicated
in Table VI, but the changes have been small although statistically
significant. The pattern of change does not appear to bear relationship
to other forms of nitrogen either in magnitude or direction. The
fact that even after 101 days the change in concentration was only
from 0.75 mg/1 to 0.70 mg/1 indicates that nothing very drastic
occurred in oxidation, biological utilization or biological conversion.
Here again Hellwig reported significant changes where biolgical activity
took place. Unpublished studies of the Lake Huron Program Office also
confirmed the scope of change where biological activity proceeds unimpeded
(Ref. 13).
Examination of Table VII points out that the nitrate nitrogen analyses
have been variable. In some cases (2 vs. 3, 2 vs. 5 and 3 vs. 5 in
Table X) the T-test indicates that no significant differences are
observed in the data. If judgment is applied, the decision could be
made to assign the difference as a function of the sample handling
employed rather than to a true change in the sample. The same comments
apply here in examining magnitude of change as were made in the Kjeldahl
and nitrite section.
The precision of the orthophosphate analysis is worthy of note as
shown in Table VIII. Although the precision is the best of all the
analyses conducted, only in the case of run 2 versus 4 did the T-test
indicate that no significant difference was observable. The relative
standard deviation appears to be much better in a difficult matrix
-------
than that reported by Winter, and Midgett, (Ref. 11).The reliance on
judgment would lead to the conclusion that an error in measurement
caused the differences between runs and no significant changes in
sample composition were evidenced.
With the exception of the ammonia analysis the total phosphate analysis
compared most favorably in run contrasts using the T-test. Thus,
run 3 vs. 4, 3 vs. 5, and 4 vs. 5 as shown in Table X when the
T-test was applied to the data indicated that there was no significant
difference in the samples. Inspection of Table IX points out a problem
in run one. This run provided the only two outliers (using the
Dixon criteria in Ref. 14) in seven sets of data.
-------
CONCLUSIONS
Samples of wastewater effluents can be preserved with 400 mg/1 of
mercuric chloride for periods of up to 100 days when stored at room
temperature. Although the statistical T-test indicated observable
differences in the majority of the comparisons, judgment in examining
the total picture provides basis that there was no major change
in the samples. An illustrative example is provided in Figure 1
where, graphically, the forms of nitrogen are presented. The mean
values are plotted as a function of time. The magnitude of the
differences in the Kjeldahl analysis cannot be explained by the
differences observed in the other forms. In fact, the Kjeldahl
differences wipe out any meaning to the nitrite determination. However,
the ammonia, nitrite and nitrate data provide credence to the fact
that nothing really changed in the sample over the hundred-day period.
The phosphate determinations, both orthophosphate and total phosphate,
are more precise than the nitrogen analyses. The relative standard
deviation expressed as a percentage for the orthophosphate analysis
at the 4.6 mg/1 level was 2.2%. Using the criteria of relative
standard deviation the orthophosphate analysis had the best precision on
a comparative basis of any of the 6 analyses performed. The total
phosphate which is the orthophosphate determination preceded by
a digestion step was superior to all nitrogen forms except the nitrite
test, again using the relative standard deviation as the criteria.
The potential for growth of organisms was present in the plastic
bottles. The storage of the bottles in the laboratory at room temperature,
mixing-aerating and the availability of nutrients for growth would have
provided changes in orthophosphate and forms of nitrogen unless
the samples had been adequately preserved. Inspection of Table
I would indicate that the seeding of organisms from the variety
-------
of wastewater effluents was a distinct possibility especially since
aseptic techniques were not used in sample handling. Despite all
the favorable factors for biological changes no major changes in
nutrient chemistry of the samples were observed. The only conclusion
one can draw from the lack of change is the effectiveness of the
preservation technique over the hundred-day period.
Why does Table X appear to indicate that that there are differences
between runs? The T-test measures random variables. Thus, sampling
errors, errors in measurement that are truly random and errors due to
sample deterioration must be considered random. If a sample deteriorating
(chemically changing through oxidation or reduction), then these changes
could be plotted as a function of time. In examining Figure 1 no indication
is provided that chemical changes in samples were the source of the random
variable. Then where did the random variable come from to indicate that
mean and variance were not normally distributed? My conclusion is that
the random variables were those of sampling and measurement (instrumental
measurement). In Table XI the wobble of the method is presented in the
form of what is acceptable from round robin studies and what was observed
in the present study. In my judgment assessment can be made with the acceptable
wobble. In all cases the observed wobble was significantly better than
what was acceptable which is another indication that the changes were not
significant from a standpoint of practicality.
-------
REFERENCES
1. Hellwig, D. H. R. "Preservation of water samples." Air and Hater
Pollution Int. Journal, Volume 8 pp 215-228. 1964.
2. Hellwig, D. H. R. Preservation of wastewater samples. Water
Research. Volume 1, pp 79-91. 1967.
3. Jenkins, D. "A study of methods suitable for the analysis and
preservation of nitrogen forms in an estuarine environment."
Report to the USPHS, Region IX. WSPC Division SERL No. 65-13.
College of Engineering and School of Public Health, University
of California. August 1965.
4. Jenkins, D. "A study of methods suitable for the analysis and
preservation of phosphorus forms in an estuarine environment."
Report to the USPHS, Region IX. WSPC Division SERL No. 65-18.
College of Engineering and School of Public Health, University
of California. November 1965.
5. Brezonik, P. L. and G. F. Lee. "Preservation of water samples
for inorganic nitrogen analyses with mercuric chloride." Air
and Water Pollution Int. Journal, Volume 10, pp 549-553. 1966.
6. Howe, L. H. and C. W. Holley. "Comparisons of mercury (II) chloride
and sulfuric acid as preservatives for nitrogen forms in water
samples." Environmental Science and Technology, Volume 3,
pp 478-481. 1969.
7. Solo'rzano, L. "Determination of ammonia in natural waters by the
phenol hypochlorite method." Limnology and Oceanography, Volume 1,
pp 799-801. 1969.
8. Anon. Methods for chemical analysis of water and wastes.
Environmental Protection Agency AQCL Cincinnati, Ohio, pp 175-183,
pp 195-197. 1971.
9. Murphy, J. and J. Riley. "A modified single solution method for
the determination of phosphate in natural waters." Analytica
Chi mica Acta, Volume 27, pp 31-36. 1962.
10. Johnson, D. L. "Simultaneous determination of arsenate and
phosphate in natural waters." Environmental Science and Technology,
Volume 5, pp 411-414. 1971.
10
-------
11. Winter, 0. A. and M. R. Midgett. Method Study 2. Nutrient
Analyses, Manual Methods. Environmental Protection Agency;
AQCL; Cincinnati, Ohio. 1970.
12. Natrella, M. G. "Experimental Statistics." National Bureau of
Standards Handbook 91, Chapter 21. The Relation between Confidence
Intervals and Tests of Significance, pp 21-1 to 21-6. U.S.
Government Printing Office, Washington, D.C. 1963.
13. Buckley, R. M. Private Communication - Program to Compute Long Term
Oxygen Demand and Nitrogen Balance from Laboratory Data Sheets and
Data Runs on a Variety of Stations from Lake Huron Program Study.
1966.
14. Natrella, M. G. "Experimental Statistics." National Bureau of
Standards Handbook 91, Chapter 17. Treatment of others, pp 17-1
to 17-6. U.S. Government Printing Office, Washington, D.C. 1963.
11
-------
LIST OF TABLES AND CAPTIONS
Table I
Changes in Total Plate Count Growth as a Function of Time
Table II
Characteristics of Samples Composited for Preservation Study
Table III
Characteristics of Sample After Compositing for Preservation
Table IV
Summary of Data for Kjeldahl Nitrogen Measurement
Table V
Summary of Data for Ammonia Nitrogen Measurement
Table VI
Summary of Data for Nitrite Nitrogen Measurement
Table VII
Summary of Data for Nitrate Nitrogen Measurement
Table VIII
Summary of Data for Orthophosphate Phosphorus Measurement
Table IX
Total Phosphate Phosphorus
Table X
T-test* Significant Difference Between Samples at 95% Confidence
Table XI
Estimated Differences in Replicates
12
-------
n
CM
r- 0
+-> O O
C 0>i
o
CJ r dl
D> C
^ E 0
>.
r- CJ £- 0) i 0)
O (!) to CX-r
C 4J 0) £ C
3 O CJ <1»
_d 4-> ) cn tn O
K? § s_
O a.
CJ
01
1 <
rt)
SI
o
i 0)
tO > r
4-> CJ <*5- «-»
o o o
s-
O <1J r-
O to ««.
h- O) 0)
Q. ^
C
O)
4J
, 0) w
IO 4-> O
O <4- Q.
10 E
O
U
-o
o>
U
0)
1^ o
O !-
o e -P
O 03
0) $- O
r- 4- 0
D. 1
CO
O C3 O O
i « r r
X X X X
rv. un o «*
csi «d- co CM
o o o o
X X X X
«^- in ro CM
cn ro co ui
tn i
o o o o
r r r" r^
X X X X
O O C3 CM
O CD LO
IjO VO t^ r '
A " "
IO CO
^O ^ O
cn cn oo co
1 r r- r
d-
cn vo co vo
r-" i ^^ t-~
CO VO "^ CM
co co r^* to
- - " "
O r- CM CO
13
Ol
QJ
O O O O
" * *~~* *
X X X X
o un co i
n- ro o o
v
cn tn 10
o o
CM CO O
t O
t*» r» to
co cn cn "d*
r-
IO |^ »J- CM
i CO
-------
1'
CM
r O
4-> CJ O
c cnr
33:--^
O to
O r- CD
cu en C
+J E o
ns i
i O O
O- ^}- c_>
=te
+J O
C CO O
3 C\O
o a: i
0 ^»
QJ ^. CU
10 E c
c O
O- CM t
o
0 <_J
CU
l
£ "i
O +J O
c -a o
C 3 CU i
o o >
.- cj i. cu in
+J 0) r CU
o cu in o.-r-
C 4J CU E C
3 iU S- fO O
U_ i Q- to i
--N (X C O
a ro 3 o
+-> in
c en
O) C3 CJ r S- E
r- O C_> CU
ja 4-> l en co o
iu c a: cu «a-
h- 3 t-
0 Q.
CJ
CU
1 »
i
+-> CO «*4- »x.
O O CD CO en
I 1 co in E
cvnj
C 2C 4-
r- Q.
in
cu_
c'
(0 T3
J=. CU
CJ >
e
O CU i
O to ~^
l cu en
i- E
Q.
C
3
CU
tO S_ -r-
>> cu co
ID 4J O
Q<4- 0.
re E
0
CJ
-o
ai
. >
T^
o
01
i C
i O
o -
0 E 4J
o re
CU L. U
r-<*- 0
a. _i
re
CO
j- j *
000
xxx
CO VO CTl
LO r-. i^
in in j-
CD O O
XXX
in CM co
*
r«- CM vo
a> «o ffl
0 O 0
XXX
in
CM CO ' «3-
i CM CM
CO CO CO
r^ co co
CO O CM
*
CO CO CO
CM CM CM
CO CO CM
co co sr
O r CM
ai
en
re
2
01
co
14
re
cu
3
^f jf rt f>
o o> o o o
r
X W X X X
CO
O _£ * CO i
in *~ sr r-^ o
v
J- -t f in J-
O O O O CD
X X X X X
O «* CM CO CO
CO CO CO CM sf
p* t* r* u> in
O O O CD O
r r r4 r r
X X X X X
to in
O o co r-. co
Lf> CO r «* SI-
CM VO O
CO CO CM O CM
r- r- i CM CM
O CO CO
*
«d- CO co «d- sr
CM CM CO CO CO
CO CO CO O O
ID CO LO CO CO
i r r
co co r» * CM
r- CO
-------
^^
-a
^j
c
o
o
» 4
cu
_Q
ra
1
cu
E
ll
o
c
o
-t->
en
ra
o
li
CM
r CD
-MOO
C COr
o to
O r QJ
cu en c
-i-" E O
ra i '
r CD O
a. ^i- o
We
4-> 0
C CO O
3 CVO
O 3= r
i CO
CU \ QJ
+J r- -r-
ra E c
r O
Q_ CM i
0
0 <_>
S
+J 0
e -o o
^3 QJ r
o > -^
O S- CO to
CU i CU
QJ 01 CX-r-
!-> CU E C
ro S- ra O
i Q_ to i
Q- e o
3 O
a i
cu ~^
c\^> CTI
C_)r- i- E
o o cu
I en to o
n: cu «a-
s.
Q.
-o
QJ
> i
CJ ^«- .
O o Q) en
1 oo to E
_^5\uj
a.
a
cu
>
(_) CU i
O to \
1 cu en
s- E
o.
c
cu
+J
to S- -f-
>> QJ to
1C 4-> O
Q 4- CL
(O F"
0
o
o
cu
cu
r C
i O
0 -r-
CJ E 4J
O ra
cu u u
r <+- 0
a. _i
E
oo
OOOCDOOCDO
t~- r i r i r r r~~
xxxxxxxx
LDi i i I~I'~~IT'~~I
OOCDOOOOO
V VVVVVVV
oooooooo
r i i i r i
XXXXXXXX
LT> r~ r" ^~ r ^ r r
OOOOOOOCD
VVVVVVV
mminmf^r^inm
OOOCDOOOO
r~~ r~~ i r-~ i"" t"" r-" t~~
XXXXXXXX
^" O^ CO ^3 CJi O^ O ^3
*
r CO CO CO r r 00 ^
Lf> LT> vo uf> P^« r** p** o>
CMCMCMCMCMCMCMCM
CM r O CM CM
CMCMCMCMr CMi r-
r cr>
CMCMi CMr- rCMr-
V V
Or cMroior^«s-CM
r CO
s_
(D
0 -»->
4J C
rC a)
T" ^
r
-C *- 1 C
to <+_ | b
T" lt.-l
LL.
-------
1 I
» 1
01
!Z
(2
^
-o
3
i
C
O
1
ro
S-
01
CD
s-
Q-
S-
°
O)
+J
r-
0
J^
(_>
o>
a.
E
ro
IO
l|_
0
(/I
o
4.)
to
.,_
S-
a>
4->
l-
ro O i
ro .C -C ~-^
+J a. a. en
o in m E
1 o o
JZ -C
a. a.
c
cu +J E
r !
c
CO CU
4-* Cnr
r- O ~^
i. s- en
u +J E
r- *r-
C
E
2z
en
c
C -t-
«4- E 0 !->
O O !-!-
L. 4J tn
S- U_ CJ O
cu ai a.
-O « r E
E >> 0
3 ro O O
Z Q CJ
o
01^
O -i- -O
l/) O
CU O T-
O- D- S-
§Ci>
a.
4-J
H- C
O 01 4*^
E c
O) +-> ro
Q. ro r
Si CU Q-
r J.
00 CM
CO ^^
r*^ f^
** in
CM OO
O LO
O 0
CM IO
oo o
0 O
r*^» ^^*
r^ co
IO O
»
CM 00
r~ r
m CM
LO in
S- S-
3: n:
00 «*
CM
j_
CU
4J
r1"
*f~
Li-
en
c
i- 01
0 3
r r
L. OO
r
Ol Ol
fO ro
o: >
1 !
§4J
U
J r^ III II'
1 1 1 1 1 II
co ro i i CM i i i ii
CM (^>i CO ID
omrocMioLncMco oo
r~ *"" ^s^ o ^^ o o o o
Lf>mi r O CM r CM
r r"~ f~^ ^^ r*"^ OO CM r*~* i i f~i
OOOr~OO'~O OO
M3 VO f1** t^^ r ^3 f1^* f^ ^3 O^
OO"^1^ r^O^-rO r OJ
'^ r- i CM
o^j-ovomooi ff
**»«( !'f
r CSJ r i r I V *
i
co "^ oo co r^ CT) r>* r** !*» oo
f^>, LO r~~ r""* ^"~ f~~ r~- r"^ r""1 t~~
S-S-t-S-S-S-S-l- S- s_
3zacnin:3:z3:z 3:0:
i OOCMCMLOOOr^CM «1-CM
r CM
_ _ X
dJ en en *o en *o en en "CJ
c: c c cu >, c a> c c j-> cu
r- -r- -r- -(-> t, -i- 4J -r- -r- C -l->
i t t rd ro »~~ ro r*~ ^ O) ro
*S vy NX > g \X > ^/ NX 3 >
O O O - -r- U -I- O O r -r-
f- -I- -r- +J J_ -r- +J -t- -r- H- -M
S-S-S-UD-S-US- S- l»- U
I I h- < r- «t r- I UJ
0
CM
C3
O
CM
r
f^
^_
w
Z
^^
CM
o
CU
ro
>
i
4->
(J
«I
+
i-
O)
r
U.
en
C 01
^* O"
i T3
O r
r- OO
S.
1
16
-------
Table III
Characteristics of Sample After Compositing for Preservation Study
Mean
Value
mg/1
Standard
Deviation
mg/1
Relative
Standard
Deviation
xlOO
Range
mg/1
Number
of
Replicates
Suspended Solids
401.0 22.0
5.5
51.0
10
Total Inorganic Carbon
18.8 1.02
5.4
3.3
10
Total Organic Carbon
76.0 16.0
21.0
55.0
10
Dissolved Mercury
2.8 0.19
6.8
0.5
10
17
-------
Table IV
Summary of Data for Kjeldahl Nitrogen Measurement
Analysis
Performed
Days After
Compositing
Run
Number
Mean
Value
mg/1
Standard
Deviation
mg/1
Relati ve
Standard
Deviation
xlOO
Range
mg/1
Number
of
Replicates
4-10
17.77
0.583
3.3
1.9
11
27-33
21.26
1.23
5.6
3.3
11
51^58
19.52
0.905
4.6
3.0
12
81
18.54
0.885
4.8
2.2
10
103
17.43
1.03
5.7
2.9
10
ALL RUNS
18.95
1.67
8.9
6.9
54
4.14
1.06
25.5
3.97
31
4.53
1.42
26.3
4.71
31
* Data taken from Methods Study 2. Nutrient Analyses. Manual Methods. 1970 (Ref. 11),
18
-------
Table V
Summary of Data for Ammonia Nitrogen Measurement
Analysis
Performed
Days After
Compositing
Run
Number
Mean
Value
mg/1
Standard
Deviation
mg/1
Relative
Standard
Deviation
xlOO
Range
mg/1
Number
of
Replicates
4-10
3.68 0.075
2.2
0.2
11
27-33
3.15 0.113
3.5
0.4
11
51-58
2.96
0.178
6.0
0-6
14
76
3.08 0.181
5.8
0.6
10
101
3.13
0.206
6.8
0.7
10
ALL RUNS
3.19 0.297
9.4
1.2
56
1.75
0.24
14.0
1.01
24
1.96
0.28
14.0
1.17
24
* Data taken from Methods Study 2. Nutrient Analyses Manual Methods. 1970 (Ref. 11)
19
-------
Table VI
Summary of Data for Nitrite Nitrogen Measurement
Analysis
Performed
Days After
Compositing
Run
Number
Mean
Value
mg/1
Standard
Deviation
mg/1
Relative
Standard
Deviation
xlOO
Range
mg/1
Number
of
Replicates
4-10
0.751 0.0030
0.4
0.01
11
27-33
0.745 0.0069
0.9
0.02
11
51-58
0.666 0.0063
0.9
0.02
15
76
0.678 0.0092
1.3
0.03
10
101
0.698 0.0140
2.0
0.04
11
ALL RUNS
0.705 0.0362
5.1
0.11
58
20
-------
Table VII
Summary of Data for Nitrate Nitrogen Measurement
Analysis
Performed
Days After
Compositing
Run
Number
Mean
Value
mg/1
Standard
Deviation
mg/1
Relative
Standard
Deviation
xlOO
Range
mg/1
Number
of
Replicates
4-10
2.59
0.024
0.8
0.1
11
27-33
2.71
0.030
1.1
0.1
11
51-58
2.71
0.070
2.6
0.2
11
76
3.13
0.095
2.9
0.3
10
101
2.71
0.095
3.7
0.3
10
ALL RUNS
2.77
0.195
7.1
0.8
53
21
-------
Table VIII
Summary of Data for Orthophosphate Phosphorus Measurement
Analysis
Performed
Days After
Compos i ti ng
Run
Number
Mean
Value
mg/1
Standard
Deviation
mg/1
Relative
Standard
Deviation
xlOO
Range
mg/1
Number i
of
Replicates
4-10
4.60
0.045
0.9
0.2
11
27-33
4.67
0.047
1.1
0.1
11
51-58
4.56
0.051
1.1
0.1
14
81
4.65
0.053
1.1
0.1
10
102
4.79
0.070
1.5
0.2
11
ALL RUNS
4.65
0.097
2.2
0.4
57
0.374
0.02
6.2
0.13
26
0.326 0.02
5.4
0.07
26
* Data taken from Methods Study 2. Nutrient Analysis Manual Methods. 1970 (Ref. 11)
22
-------
Table IX
Total Phosphate Phosphorus
Analysis
Performed
Days After
Compositing
Run
Number
Mean
Value
mg/1
Standard
Deviation
mg/1
Relative
Standard
Deviation
xlOO
Range
mg/1
Number
of
Replicates
4-10
6.09
0.105
1.8
0.3
9*
27-33
6.58
0.125
2.0
0.4
11
51-58
6.97
0.179
2.6
0.5
11
81
6.92
0.114
1.6
0.3
10
115
6.98
0.147
2.1
0.4
11
ALL RUNS
6.73
0.321
5.4
1.3
52
**
0.89
0.13
14.4
0.76
33
**
0.81
0.13
16.0
0.78
33
*Two outliers were not considered. The "Dixon" outlier test used by Natrella was the
basis for rejection.
** Data taken from Methods Study 2. Nutrient Analysis Manual Methods. 1970 (Ref. 11)
23
-------
Table X
T-test*
Significant Difference between Samples at 95% Confidence
Run K-N NH3-N NOg-N N03-N Ortho P Total P
1 vs 2 yes yes yes** yes yes yes
1 vs 3 yes yes yes yes yes** yes
1 vs 4 yes** yes yes yes yes** yes
1 vs 5 no yes yes yes yes yes
2 vs 3 yes yes yes no yes yes
2 vs 4 yes no yes yes no yes
2 vs 5 yes no yes no yes yes
3 vs 4 yes** no yes yes yes no
3 vs 5 yes no yes no yes no
4 vs 5 yes** no yes yes yes no
* Ref. 12
** No difference at 99.5% confidence level.
24
-------
Table XI
Estimated Differences in Replicates
Measurement
Acceptable
Relative
Standard
Deviation
X 100
Observed
Relative
Standard
Deviation
X 100
Kjeldahl Nitrogen
25*
8.9
Ammonia Nitrogen
14*
9.4
Nitrite Nitrogen
10**
5.1
Nitrate Nitrogen
10**
7.1
Orthophosphate Phosphorus
6*
2.2
Total Phosphate Phosphorus 15V
5.4
*Ref. 11, Method Study 2.
**Estimate from Analytical Quality Control Charts.
25
-------
LIST OF FIGURES INCLUDING CAPTIONS AND LEGENDS
1. Figure 1
Forms of Nitrogen Levels as a Function of Time
Legend: O Kjeldahl Nitrogen, > Mean Kjeldahl Nitrogen,
£ Ammonia Nitrogen, O Nitrate Nitrogen,
O Nitrite Nitrogen
26
-------
<0
0
o
CD
OO
n
<0
<
Q
CD
CO
i i
CVJ
vO
CSJ
OO^O
27
Region V, Library
230 South Daarbonj Street
Chicago a Illinois
------- |