903979003
     U.S. ENVIRONMENTAL  PROTECTION  AGENCY
r
L

r
L
     MIDDLE ATLANTIC REGION- III  6th and Walnut Streets, Philadelphia, Pennsylvania 19106

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EPA 903/9-79-003
                                      CARBONACEOUS AND NITROGENOUS
                                          DEMAND STUDIES OF THE
                                             POTOMAC ESTUARY
                                               (Summer 1977)
                                    Annapolis Field Office, Region  III
                                      Environmental Protection Agency
                        Joseph Lee Slayton
                        E. R. Trovato

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                              DISCLAIMER






     The mention of trade names or commercial products in this




report is for illustration purposes and does not constitute endorsement




or recommendation by the U.S.  Environmental Protection Agency.

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                          TABLE  OF CONTENTS


                                                                 Page

      Tabulation of Tables                                        iii

                                  |
      Tabulation of Figures                                       iv


  I.   Introduction                                                 1


 II.   Conclusions                                                  4


III.   Procedure                                                    6


 IV.   Oxygen Demand in The Potomac River  Samples


         A.   Biochemical  Oxygen  Demand -  Carbonaceous


             1.   General  Discussion                                7


             2.   Standard BODs Test                                7


             3.   CBOD/First Order Kinetics                          8


             4.   Thomas Graphical Determination of
                   BOD Constants                                  10


             5.   Temperature Effect Upon  Reaction Rates            14


             6.   Nature and Distribution  of  CBOD                   19


         B.   Biochemical  Oxygen  Demand -  Nitrogenous


             1.   General  Discussion                               27


             2.   Bacterial Growth Requirements                     28


             3.   Lag Phase and Growth Characteristics              29


             4.   Stoichiometry of Nitrification                   30


             5.   Nitrification Kinetics                           43


             6.   Nature and Distribution  of  NOD                   43


  V.   Oxygen Demand in the Potomac STP Effluent Samples


         A.   CBOD                                                 51


         B.   NOD                                                  51


         C.   Loadings Characteristics                             54

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              TABLE OF CONTENTS (con't)






                                                           Page




References                                                  67




Appendix:




A.  N-Serve/NOD Determinations                              69




B.  Alternative Methods                                     70



C.  Study Data                                            72-84
                          11

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                                TABLES


No.                                                               Page

 1.  Station Locations                                              3
 2.  Thomas Graphical Determinations of k^g, and Lo,
       for river CBOD's                                            12
 3.  Thomas Graphical Determinations of k^Q, and Lo,
       for river BOD's                                             15

 4.  Chlorophyll a_  vs  CBOD                                       26

 5.  NOD2Q  vs  (TKN-N x 4.57)                                     32
 6.  Thomas Graphical Determinations of k^Q, Lo, and r
       for river NOD's                                             44

 7.  Ratios of NODs/BODs and NOD20/BOD2Q                           48

 8.  Thomas Graphical Determinations of kio> Lo, and r
       for STP CBOD's                                              52
 9.  Thomas Graphical Determinations of k^g, L0, and r
       for STP NOD's                                               55

10.  Summary sheet of % [NOD2o/NOD Ultimate] for STP's             60

11.  STP Loadings of CBOD20> NOD Ultimate, and BODs                61

12.  Proportion of Total STP Demand Expressed as NOD               63

13.  N02-N Concentration and the Resulting NOD Error               65

14.  Potomac River Long-Term BOD Survey Data                     72-84
                                   111

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                                       FIGURES





       No.                                                                Page




        1.         Study Area                                               2




        2.         Depletion Curve for BOD and CBOD                        17




      3-8.         BOD2Q. CBOD2Q and NOD20  vs  River Mile Index (RMI)    20-25




        9.         Plot of NOD2Q  vs  (TKN-N x 4.57)                        35




10,  12-16.         Plot of NOD20 and (TKN-N x 4.57)                     36, 38-42




       11.         NH3-N, N02-N, N03-N and TKN-N  vs   RMI                   37




       17.         NOD Depletion Curves                                    46




    18-20.         BOD, NOD, and CBOD Oxygen Depletion Curves            57-59
                                           IV

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 I.   Introduction




     During the summer of 1977 an intensive survey of the middle reach




of the Potomac River (Figure #1)  was undertaken by the A.P.O.   All




samples were collected under slack tide conditions.  As part of this




work, 20-day B.O.D. analyses were performed on selected stations




(Table #1) to help define the major oxygen demand inputs and establish




their effect upon the river.  The fraction of the B.O.D. associated




with nitrogenous oxygen demand was determined using an inhibitor to




nitrification.  To afford a more  meaningful intrepretation of the




results, a discussion is included on the B.O.D. test; nitrification;




and the nature and action of the  inhibitor employed.

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Figure 1.  Study Area
                                                 Potomac Estuary

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Table #1

Station
Number
P-8
P-4
1
1-A
2
3
4
5
5 -A
6
7
8
8-A
9
10
10-B
11
12
13
14
15
15-A
16


Station
Number
S-l
S-2
S-3
S-4
S-5
S-6
S-7
S-8
Stations
for
Long Term
BOD/NOD
X

X


X
X
X

X
X

X

X

X






Stations
for
Long Term
BOD/ NOD
X
X
X
X
X
X
X
X


Station Name
Chain Bridge
Windy Run
Key Bridge
Memorial Bridge
14th Street Bridge
Hains Point
Bellevue
Woodrow Wilson Bridge
Rosier Bluff
Broad Creek
Ft. Washington
Dogue Creek
Guns ton Cove
Chapman Point
Indian Head
Deep Point
Possum Point
Sandy Point
Smith Point
Maryland Point
Nanjemoy Creek
Mathias Point
Rt. 301 Bridge



Treatment Plant Name
Piscataway STP
Arlington STP
Blue Plains STP
Alexandria STP
Westgate STP
Hunting Creek STP
Dogue Creek STP
Pohick Creek STP


RMI
0.0
1.9
3.4
4.9
5.9
7.6
10.0
12.1
13.6
15.2
18.4
22.3
24.3
26.9
30.6
34.0
38.0
42.5
45.8
52.4
58.6
62.8
67.4



a, RMI*
18.4
5.9
11.1
12.4
12.8
20.0
22.3
24.5


Buoy Reference





C "1"
FLR-23' Bell

C "87"
N "86"
FL "77"
FL "67"
R "64"
FL "59"
N "54"

R "44"
N "40"
N "30"
G "21"
N "10"
C "3"













The RMI's are approximate since the STP's are often located on ewbayments

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II.  Conclusions






1.  CBOD of the Potomac River samples followed first order kinetics




    with an average ke=0.14 day~l.




2.  In August, a significant increase in CBOD, between Gunston Cove




    and Possum Pt., correlated (r=.94)  with an algae bloom of




    Oscillatoria.




3.  NOD of Potomac River samples between Hains Point and Ft.  Washington,




    (peak NOD area) followed first  order kinetics with an average




    ke=0.14 day"1.  The exceptional samples had significant lag times




    resulting in S-shaped or consecutive S-shaped D.O. depletion




    curves.  These samples were limited to the algal bloom area and to




    samples from the Chain Bridge area which had low NOD2Q (2.0 ppm average).




4.  In general, the NODj- represented about one-third of the BOD5 of the




    river samples and therefore, estimates of CBODs from 8005 values




    are prone to error unless a nitrification inhibitor is employed.




5.  The CBOD2Q represented 68% of the river demand2Q-




6.  The CBOD of the STP effluents followed first order kinetics with




    an average ke=0.17 day~l.




7.  The CBOD2Q represented 31% of the STP effluent demand20-




8.  The NOD for the STP effluents had a significant lag time resulting




    in S-shaped or consecutive S-shaped depletion curves.  This lag time




    was probably an artifact, since nitrification in the receiving




    waters was immediate.




9.  The NOD20 observed for river samples did not significantly differ




    from (TKN-N x 4.57) which suggests:

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II.  Conclusions (con't)




         a.   Nitrification was essentially complete after 20 days




             of incubation.



         b.   The nitrification inhibitor 2-chloro-6 (trichloromethyl)




             pyridine (common name nitrapyrin),  gave accurate NOD results.




         c.   The NOD observed was due to autotrophic bacteria since




             the inhibitor was specific for Nitrosomonas spp.




10.  The relation CBOD2o  =1.85 CBOD5 held consistently for the Potomac




     River samples and, with the use of nitrapyrin, short term experiments




     may yield adequate estimates of ultimate demand via the relation:




     UBOD =1.85 CBOD5 +4.57 (TKN-N).

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III.Procedure




BOD:  The BOD test employed was that outlined in Standard Methods




      APHA 14th edition*.  Dilutions were made for the S.T.P.




      samples using BOD bottles, that were within ± 1% of 300 ml,



      as volumetric flasks.  S.T.P. samples were diluted with APHA




      dilution water; seeded using 1 ml per bottle of stale raw-




      settled S.T.P. influent; and dechlorinated.  All samples were




      purged for 15 seconds using purified oxygen and a Fisher gas




      dispersion tube to obtain an initial DO of 10-15 ppm.



DO:   All dissolved oxygen measurements were made using a YSI BOD




      probe #5750 and a YSI model #57 meter.  These were calibrated




      against the Winkler (azide modified) method*.








Nitrification:  The nitrification inhibitor (Hach Chemical Co. #2533)




      was dispensed, using a powder dispenser, directly into the BOD




      bottles.  This allowed quick and uniform additions of the




      inhibitor.  Two bottles were filled with each sample; one



      received the inhibitor and represented CBOD and the uninhibited



      bottle expressed total BOD.  The NOD was determined by difference.



Nitrogen-Series:  TKN-N was analyzed by the automated phenate method-'-.



      The N02~N + NO^-N was analyzed by the automated cadmium




      reduction method*.

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 IV.  Oxygen Demand in the Potomac River Samples




  A.  Biochemical Oxygen Demand-Carbonaceous




    1.  General Discussion
     Biochemical oxygen demand is a bioassay procedure concerned with




the utilization of oxygen in the biochemical oxidation (respiration)




of organic material.  This test is one of the most widely used




measures of organic pollution, applied both to surface and waste




waters.  The BOD test has been relied upon in the design of waste




treatment plants and to establish standards for effluent discharges.




One of the primary disadvantages of this test is that as a bioassay




it reflects biological variability.  The test is not a relatively




simple assay whereby  pure strains of bacteria interact with a well-




defined media, but involves monitoring a complex and changing




population of microorganisms (bacteria, protozoa, fungi, algae, etc.),




as they respire in a changing mixture of organic matter.  Interlaboratory




studies have established its precision on synthetic samples to be




± 20% at 2i 200 ppm BOD .  The accuracy of the test is difficult to




assess since the results obtained for "standard solutions" vary




markedly with the seed employed .




    2.  Standard BODg Test
     The standard method of BOD measurements, adopted by APHA1,




is a five-day test at 20°C in the dark.  The five-day incubation period




was selected to maximize that portion of the oxygen demand associated




with heterotrophic respiration (oxidation of carbon compounds)




and, at the same time,  minimize the oxygen demand of autotrophic




organisms, primarily nitrifying bacteria.  The basis for this method

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IV-  Oxygen Demand in the Potomac River Samples (con't)








selection rests upon the generally observed 10-15  day lag in oxygen




uptake associated with the growth of nitrifying bacteria in sewage




samples.  This assumption was found to be erroneous for Potomac




River samples.




     The standard BODr test was designed to provide the biota with




the macronutrients and oxygen necessary for growth, such that the




rate of utilization of organic material will be limited only by the




amount and nature of the organic material present.   In comparison




to a long-term test of 20 or 30 days, the short-term test is more




severly dependent upon the number and type of biota introduced (seed)




and the temperature of incubation.  These factors  will affect the




kinetics of respiration.  In essence the standard  8005 test ^or




sewage effluents was not designed to give accurate rate estimates,




but its use as a best estimate remains because of  the absence of an




alternative.  BOD tests of river water involved no dilution nor seeding




and may have the best correlation with actual river rates, since the




least manipulation of the sample is involved.  Because the kinetics




of the process are largely avoided when measuring  plateau values,




which are not measureably affected by seed conditions or temperature




value between 4 and 20°C , the ultimate oxygen demand has been cited




as a more practical parameter for judging the potential pollution load .




    5.  CBOD/First Order Kinetics




     The kinetics of the carbonaceous BOD observed during this study




were first order.  The observed oxygen utilization fell off exponentially




with time, and approached an ultimate asymptote.  The first order

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characteristic is thought to be the summation of many different

reaction rates of the gamut of material expected in waste and river

samples.

     The expression relating the remaining oxygen demand L, at time

t is given by:

                  -dL = k Lo       equation #1
                   dt

such that the rate at any instant is proportional to the amount of

BOD yet to be expressed.  Lo is the intial remaining oxygen demand (at t=o)

or ultimate demand and k is the deoxygenation rate constant, day

Rearranging and integrating equation #1

                    L
                           =  k /  dt
where  tQ = 0,

   = -(In L-ln Lo) = kt

   or In L = In Lo - kt            equation #2

The - kt term can be expressed as In e~kt, since In ex = X, and equation #2

becomes

                   In L = In Lo + In e"kt

or the familar expression

                   L = Lo e~       equation #3

However, the BOD test actually involves the measurement of oxygen

consumption rather than the amount left to be depleted, so a new variable

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                                                                    10
y (oxygen depletion) is introducted such that


           y = Lo -L


and substitution into equation #3 yields


           y = Lo (l-e~kt)                equation #4


The average ke value reported 5 for the Thames River STP effluent


samples was 0.234 day"1 which results in



           y/    - (1.eC-234)(S))

            /Lo



     or    Lo = 1.45 y


     or    BOD ultimate = 1.45 x BOD5


It should be cautioned that the equivalent expression


           y = Lo (l-10"klt)              equation #5


is often employed with k=k'x2.303


The observed Potomac River samples' CBOD^ and CBOD2Q data, included


in Table #2, gave the following best fit function:


                      CBOD2Q = 1-85 CBOD5


with a correlation coefficient of 0.945 based upon 53 data pairs.


    4.  Thomas Graphical Determination of BOD Constants


     All data points (6 or 7 readings per sample over the 20 day


incubation period) were also used to give the best available estimate


of k^g and L by using the Thomas Graphical Determination^'?.  This


method relies upon the observation that the relation (l-10~kt) is

                                     _T
very similar to 2.3 kt [l +  C^-3-) kt]
                              6

such that by using equation #5


                      y = 1^2.3 kt [l + (^) kt]"°

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                                                                     11
or
                      1         (2.3k)2/3 t    equation #6
                  (2.3L0k)    * (6LQ)1/3

A plot of f ^/\^"   vs t yields a linear relation with slope
m = (2.3k)2/3 and intercept b =
        ,1/3
                                C2.3kL0)
BOD k^Q and L values can be determined from equation #6 as follows

                           (2.3k)2/5    slope
                            C6L0)1/3
                  m  =
                  b
                  m
                  b
           (2.3kL )*/3     intercept

           (2.3)2/3 x (2.3)1/3 x k2/3 x
or
          k = 2.61m
                b

Also since b = (  1  ^ 1/3 it follows that Lo= 	1
I 2.3klJ
                                               2.3b3k

The end result is that the two variables L0and k^g are related to

a close approximation to y and t by two simple equations which

allow their solution.

     To facilitate the calculation of Thomas constants, a computer

program was written to compute the k^Q and LQ.
     The results are compiled in Table #2.  The average  (n=43) k-^Q

value observed for river CBOD's was k^g = 0.062 days'-'- or ke = 0.14 days"*,

The correlation coefficients (.30-. 99):

                    y = L0 (l-10-kt) * 2.3kt (1+ 2^3l!) "
                                                   6
suggests first order kinetics.  The value predicted by the
                     Q
Dynamic Estuary Model  (DEM) for the deoxygenation rate constant,

kp, of CBOD's at 20°C was 0.17 days"1.

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TABLE # 2
CBOD RIVER
                                                                    12
 DATE - STA
                THOMAS GRAPHICAL DETERMINATION
July 27 -
Aug.  3 -
Aug. 24 -
P8
1
3
4
5
6
7
8-A
10
11
P8
1
3
4
5
6
7
8-A
10
11
1
3
4
5
6
7
8-A
10
11
P8
1
3
4
5
6
7
8-A
10
11
0.070
0.049
0.057*
0.065
0.062
0.035*
0.053
0.073
0.069
0.051

0.058
0.067
0.056
-
0.041
-
0.001*
0.065
0.020*
.071
.018*
.066
.066
.083
.055
.060
.055
.057
.059
.078
.067
.075
.066
.065
.052
.032*
.032*
.012*
5.41
6.76
8.67
6.51
8.40
11.78
8.80
6.85
6.69
7.99

3.85
5.62
4.67
_
10.18
_
15.60
5.61
7.91
4.39
10.51
7.04
5.93
5.98
7.31
8.26
7.02
6.43
6.15
4.68
4.46
6.19
9.28
8.66
10.40
20.93
23.78 -
22.38J~


1 lag phase


1 lag phase











1 lag phase


1 lag phase














8/24 bloom
300 ppb chloi
CBOD 5
3.0
3.0
5.2
2.6
4.4
5.3
4.2
4.0
3.8
3.8
1.8
3.0
2.3
3.0
4.0
3.1
3.0
1.9
2.3
3.0
3.7
3.2
3.5
3.6
3.9
3.2
2.9
3.1
2.6
2.2
3.6
5.2
4.3
4.6
7.6
6.6
2.8
CBOD2Q
5.0
6.0
8.2
5.9
7.6
9.7
7.9
6.2
6.2
6.9
3.5
5.1
4.1
5.1
8.9
6.4
5.1
4.6
4.1
5.1
6.6
5.2
5.3
6.5
7.8
6.4
6.2
5.8
4.3
4.2
5.7
8.6
8.0
9.4
15.4
17.3**
9.0**
                                                     _
                                   Algae  major  contributor

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TABLE # 2  (con't)            CBOD RIVER                            13
                THOMAS GRAPHICAL DETERMINATION
 DATE - STA        k10         Lo                       CBODs   CBODzO
Aug. 31 - P8       .058       4.17                       2.1      3.8
           1       .061       4.65                       2.4      4.3
           3       .014*      13.80      1 lag phase       3.2      5.7
           4                                             3.8      6.5
           5       .053       7.59                       3.7      6.7
           6       .091       8.17                       5.2      7.2**
           7       .062       10.00                       5.1      9.2
         8-A       .050       12.54                       5.2     11.1
          10       .055       12.98                       6.3     11.9
          11       .059       9.48                       4.6      8.7

Sept. 8 - P8       .043       5.25                       2.0      4.5
           1       .069       4.91                       2.6      4.5
           3       .056       5.31                       2.5      5.0
           4       .081       8.01                       4.8      7.4
           5       .056       9.76                       4.8      8.8
           7       .071       4.80                       2.6      4.5
         8-A       .065       6.35                       3.2      6.1
          10       .018*      14.66      1 lag phase       3.9      7.3
          11       .035*      8.72           *            3.1      6.9
 * Not included  in  calculation of average kjQ due to their exceptionally
   low correlation  coefficients  and lag  periods  in  growth

** Deleted from  calculation of CBOD5/CBOD2Q


            k!0  :

                n = 43
          average = .062
             s.d. = .010

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                                                                      14



     The total BOD for the river samples (Table #3) also followed



first order kinetics with correlation coefficients over the range



of (1.000 to .156) with an average (n=50) kjo of 0.054 day"1.



This rate corresponds to an expression of 47% of the ultimate BOD



after 5 days such that:          BOD2Q = 2.1 x BOD5


An oxygen depletion curve is included in Figure #2.



     5.  Temperature Effects Upon Reaction Rates



     Any statement concerning the observed B.O.D. reaction rates



should take into consideration the potential error due to fluctuation



in the incubation temperature.  If it is assumed that over a narrow



range biochemical reaction rates tend to increase, as do strictly



chemical reactions (endothermic), with increasing temperature,



then the effect of temperature upon the rate of these reactions may



be approximated by the Arrhenius equation^:        k = Ae"  '



were A is the frequency factor or pre-exponential factor (time  );



Ea is the activation energy,  (energy/mole); T is temperature in



°Kelvin and R is the ideal gas constant  (energy x temp x mol  ).
Taking the natural log:
                                 -Ea
                          In k = 	+ In A

                                  RT
and differentiating with respect to temperature:


                    d In k   =   d In A   -   d Ea_

                     d T          d T           RT


                                               d T



but A, Ea and R are all constant with respect to T.



or:                 d In K   =   -Ea  d T'1   =    Ea_

                     d T          R    d T         RT2

-------
TABLE # 3
BOD RIVER
                                                                    15
 DATE - STA
July 20
July 27 -
Aug. 3  -
Aug. 24 -
TA
P8
1
3
4
5
6
7
8-A
10
11
P8
1
3
4
5
6
7
8-A
10
11
• P8
1
3
4
5
6
7
8-A
10
11
• P8
1
3
4
5
6
7
8-A
10
11


kio
.037
.032
.058
.027
.049
.. 036*-
.040
.058
.048
.051
-.023*
.047
.060
.057
.047
.059
.041
• 003*
.053
.023
.105
.081
.063-
.079
.080
.045
.030
.049
.039
.042
.045
.047
.072
.081
.063
.059
.049
.011*
.010*
-.004*


9.10
10.95
13.27
18.31
21.14
24.5-
14.71
10.74
10.59
10.53
-2.99
5.73
8.50
10.60
11.87
16.45
14.08
100.0-
7.95
12.75
2.38
5.85
13.99
12.14
11.08
9.45
11.50
13.12
12.50
9.17
9.52
7.83
9.01
10.99
12.99
13.00
14.45
62.48
68.80
-63.35







1 lag phase



2 lag phases





1 lag phase

















1 lag phas"e~)
1 lag phase h al§a^
, linear^ J chloro
1
r=.999
m=.673
b=-.232
                                                                 300 ppb

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                                                                     16
TABLE # 3  (con't)             BOD RIVER
 DATE - STA           k10             L0
Aug. 31 - P8          .063           5.73
           1          .056           5.97
           3          -054*          14-76     1 lag phase
           4
           5          .073           12.77
           6          .075           12.96
           7          .071           14.80
         8-A          .059           17.89
          10          .045           19.62
          11          .044           15.66

Sept. 8 - P8          .016           13.04
           1          .039           8.11
           3          .066           10.39
           4          .060           18.65
           5          .060           22.81
           6          .066           12.60
         8-A          .062           9.84
          10          .026*          15.10     1 lag phase
          11          .023           16.12
* Not included in calculation of average k due to their exceptionally
  low correlation coefficients and lag periods in growth
          k!0:

               n = 50
         average = .054
            s.d. = .017

-------
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          ro-
          00'
       1-3



       I
           ro
           o
                    Oxygen Depletion mg/1
                    ro
                    •

                    o
                            o
                           -t—
                                  —i
 CO
 •

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—I—
 p

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~T—
                                                        M
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                                                        H-
        CO
        •


        M

        t-<
                                                            a>
                                                            00
                                                                                              Oxygen Depletion mg/1
° £—V-
                                                                                    ro -
                                                                                    00 -
                                                                                (O
                                                                                    tu'
                                                                                    00
                                           ro
                                           o
                                     K>
                                                                                                         o
                                                                                                         o
                                                                                                                                        ro
                                                                                                                                        5?
                                                                                                                                        (B
                                                                                                                                        8
                                                                                       03



                                                                                       is
                                                                                           M
                                                                                       O <
-------
                                                                    18
Integrating over temperature and rate
                                   /T2
                     d In k  =     /     §i_  d T

                                Tl'     RT2
                                       \ 2.    "7
              In k2 - In kj_   =   Ea   \    T"^ d T


                                  R   TV



              In
                   11      R    \T1    T2J




              In /k2\  =   Ea   /T2 - TL\              equation #7
     Because the original assumption is that only a limited temperature



range be considered, T]_ x T2 (in K ) is essentially constant.   Let



Ea     =  9, which has been termed the temperature coefficient.

RTXT2



Substitution of 6 into equation #7.



                        In ACT /  \  ^   €
Experimentally determined 6 values have been found to be reasonably



constant over narrow temperature ranges with the average value for



temperature coefficient over the range 5-25°C being reported '   as



0.056 "C"1 and 0.047  "C"1.  The observed difference between experimental


                                                 1 5>1:L
(ke = 0.143 day'1) and classical (ke = 0.234 day"1)     rates cannot



be explained based soley on fluctuation in incubation temperature.  This



can be shown by substituting these values into equation #7



                       In f"234\  =  0.056  (20-T1°C)         Equation #8

                            -143/

-------
                                                                    19
and solving for T^
                     !]_ = 11°C.

A  9°C variation in temperature is necessary to explain the difference

in rates.  The observed fluctuation of the Jordon Model #818 BOD

incubator was 20 +_ 1°C (measured with an NBS certified thermometer)

during the course of the Potomac Survey.  Therefore it may be

concluded that the observed rate cannot be explained by temperature

fluctyation.

     6.  Nature and Distribution of CBOD

     The distribution of the CBOD20 vs RMI and STP locations are

compiled in figures 3-8.  The peak(s) CBOD area extended from the

Memorial Bridge to Gunston Cove, which corresponds to the locations

of the major STP's:  Arlington; Blue Plains; Alexandria; Westgate;

Piscataway; Hunting Creek; Dogue and Pohick.

     A second CBOD peak area was observed on August 24 (figure 6)

which corresponded to an algal bloom with a chlorophyll a concentration

of ^ 300ppb.  The chlorophyll a_ and CBOD data for stations 8-A, 10, and 11

are compiled in Table #4.  The high correlation obtained (r=.94 and

n=18) suggested this second peak demand area was largely attributable

to algal decomposition and/or respiration.  The kinetics of the CBOD

process for stations 8-A, 10, and 11 were first-order exponential but

were abnormally slow (Table #2).  These data points were not included

in the calculated ke of 0.143 day"-'-.

     The average CBOD2Q entering the study area at Chain Bridge was

4.6 ppm while the average NOD2Q was 2.0 ppm.  Figures 3 thru 8 reveal

-------
                                                July  20,  1977
                                                                          BOD2Q 0

                                                                         CBOn20 X

                                                                          NOD20 Q
?   *   I
1   I   1   i  I
   Miles Below Chain Bridge


1   I   I   *   I    *   1    '
                                                                                                                T)
                                                                       H
                                                                       a>

-------
t  i   l   i   i  I   I  i   I  *   !   1
!   I   I  j   1
                                                   July 27, 1977
                                                                                    BOD20 0

                                                                                   CBOD20 X
                                                                                    NOD
                                                                                       2Q
                                                             18
                  20
22
24
26
28
30
32
34
                                                                                                                     -n
                                                                                                                     H-
                                                                                                                     oq
36
38
                                                            RMI

-------
                                               August 3, 1977
                                                                                                                 1
                                                                                                                 (0
                    BOD
                                                                                    20
                                                                                       0
4-
2-
                                                                                CBOD20 X

                                                                                 NOD2Q -
                                                        RMI
     ?  1   «•  I   f  t   f  1   f  I   I  I   I   I   I   I
*  1

-------
i  i   i   i   i   }    f
i   r   i   i  i   i  t   f  i   r   i
                  August  24, 1977
i  i   f  )   i   i   i   i   i   i   f  i   i   i
                                                                                                      32    34    36     38

-------
               August 31,  1977
                                     BOD2o 0
                                    CBOD2Q X
                                     NOD20
10
                                                                                      38
                       RMI
!   ft
fl      1   ?
rill   fi   fi   ||   fi   ft   if
                                                                      fi

-------
  i  I   f  j   f  1   !
f   i   f  i   f  i   i   s   r   ]   t   i  '  i   i    i
                                                                                          1   t   i
                                                   September 8,  1977
                                                                              BOD20 0
                                                                             CBOD20 X
                                                                              NOD
                                                                                 20
                                                                                    •n
                                                                                                                         00
                                                                           22     24    26    28
                                                                                        38
K)
01
                                                            RMI

-------
                                                                    26
TABLE # 4
Date
July 20


July 27


Aug. 3


Aug . 24


Aug. 31


Sept. 8






Station #
8 -A
10
11
8-A
10
11
8-A
10
11
8-A
10
11
8-A
10
11
8-A
10
11
n=18
r=.942
m= . 046
b=1.907
                              Name
                          Gunston Cove
                          Indian Head
                          Possum Point

                          Gunston Cove
                          Indian Head
                          Possum Point

                          Gunston Cove
                          Indian Head
                          Possum Point

                          Gunston Cove
                          Indian Head
                          Possum Point

                          Gunston Cove
                          Indian Head
                          Possum Point

                          Gunston Cove
                          Indian Head
                          Possum Point
Chlorophyll a'
ppb
86.2
81.0
90.0
123.0
129.0
112.5
103.5
76.5
85.5
306.0
312.0
168.0
187.5
195.0
148.5
85.5
100.5
120.0
CBOD20
ppm
6.2
6.2
7.2
6.4
5.1
4.6
7.8
6.4
6.2
15.4
17.3
9.0
11.1
11.9
8.7
6.1
7.3
6.9

-------
                                                                    27




that CBOD is in general more significant than the NOD for the river




samples.  This may be attributed to the greater masses of carbon




in the system8.  The average NOD2o/BOD20 (Table #7) was 0.38, (n=58).




The algal bloom area exhibited the same trend which reflects the algae




C/N ratio of 4.6 found by elemental analysis.  The few exceptions




to the dominant CBOD pattern were restricted to river locations




adjacent to the sewage plants in the reach from the 14th Street




Bridge to Broad Creek.  Nitrification was largely completed above




the algal bloom area.




  B.  Biochemical Oxygen Demand - Nitrogenous




    1.  General Discussion




     Nitrification is the conversion of NH3 to N03 by biological




respiration.  This type of respiration is employed by seven genera




of autotrophic nitrifyers  as listed in Bergey's manual12.  However,




only Nitrosomonas stvp and Nitrobacter spp are regularly reported by




in situ nitrification studies13.  In general, the treatment of




nitrifying river samples with inhibitors specific to Nitrosomonas




and Nitrobacter can be expected to stop all appreciable nitrification




It should be noted that heterotrophic nitrification can also occur




whereby N02 and N03 are formed by reactions that do not involve




oxidation.  The contribution due to these organisms was not found to




be significant in the Potomac River, since a close correlation was




observed between the expected NOD  (associated with TKN-N) and the




measured NOD which was specifically limited to autotrophic bacteria.

-------
                                                                     28
    2.  Bacterial Growth Requirements

     Nitrifying bacteria prefer temperatures of 35-40°C but can

survive well over the range of 4-45°C^-^.  The rate of nitrification

increases with increasing temperature throughout the range of 5-35°C

Nitrifying bacteria are more temperature sensitive than heterotrophic

bacteria and their contribution to B.O.D. will vary more markedly

with temperature.  BOD samples assayed during winter months should

incorporate a nitrification inhibitor to yield results more relevant

to river conditions.  The temperature ranges observed during this

summer's Potomac survey were very narrow:

                    Date          Temperature Range °C
                  July 20                31-29
                  July 27                28-25
                  Aug. 3                 28-27
                  Aug. 24                26-27
                  Aug. 31                30-28
                  Sept. 8                28-27
                                                    14
Nitrifyers can generally tolerate a pH range of 6-10   .  The "ideal"

values seems to vary with the particular environmental conditions

from which the tested bacteria were selected but in general a
slightly basic pH seems ideal  O8.0).  At pH  levels below  7,

                                                               Dissolv
                                                                      5,13,14
                                                         14
the rate of maximum growth was decreased by more than 50%  .  Dissolved
oxygen does not  seem  to affect the rate  of their  growth above  O.Sppm.'

The average temperature and pH measured  over  the  course of this  study

were  27.0°C and  7.6 respectively.

      The reactions involved in nitrification  are  as  follows:

m                      +  j.  TL ri NitrOSOfflOnaS. 714+ ,  vin  ~ + H n  prmatinn #Q
                     .   -r  1.^5 U^j             i L,\\  "t"  i\Uo  • novj  cv-^LAdL.j.\jii ~ y
                    42                      ^     ^

                  N02"  +  h 02 Nitrobacter?  N03~              equation #10

-------
                                                                    29
An average pH of 7.6 was found in the Potomac River long term BOD



samples.  The pka of ammonia at 25°C is 9.26  .   These factors



combined with the Henderson-Hasselbach equation:




                     pH = pka + log   base

                                      acid



establish that Nffy  should be used in the preceeding equations and



that ammonium (NH^) represents 98% of all ammonia species present.



    5.  Lag Phase and Growth Characteristics



     Nitrosomonas have a maximum growth rate less than that of



Nitrobacter and heterotrophic bacteria in general have a maximum


                         14
growth rate nearly double   that of autotrophic  bacteria (doubling time



of 30/hr)13.  For STP effluent samples an NOD lag time of 10-15



days often occurs due to the slow growth of nitrifying bacteria and



the small population initially present.   For this reason, nitrogenous



oxygen demand is often termed second stage BOD.



     Nitrifiers not only have a slower growth rate but also are more



fragile than heterotrophic bacteria, resulting in more sporadic



results from an NOD experiment than from CBOD tests  .   The growth



of nitrifiers are inhibited by a wide variety of substances as  :



     halogens; thiourea and thiourea derivatives; halogenated solvents;



     heavy metals;  cyanide; phenol;  and  cresol.



A study of 52 such compounds known to inhibit nitrification revealed



that the inhibition of Nitrobacter is less severe than that of



Nitrosomonas; Nitrosomonas representing  the weak link in nitrification  .



     Nitrification is a surface phenomenon with much of nitrification



occurring in clear,  shallow rivers on the surfaces of mud (aerobic).

-------
                                                                    30





plants, slime, etc  .   Laboratory experiments involving the incubation



of clear-shallow stream samples would not be expected to reflect



the extent of in situ nitrification.   However in a turbid estuary,



such as the Potomac, the surface area of the suspended material is



expected to exceed that of the river bed, such that nitrification



would be expected to be more significant in the water column.   Tests



of such water samples should estimate the extent of nitrification



actually occurring in the estuary.



    4.  Stoichiometry of Nitrification



     The Stoichiometry of the nitrification reactions , equations #9 $ #10



dictate that the conversion of 1  gram of nitrogen from- ammonia to



nitrite utilizes 3.43 gx'ams of oxygen and the conversion of 1 gram of



nitrite-nitrogen to nitrate involves the utilization of 1.14 grams of



oxygen.  However, nitrifying bacteria are autotrophic and as such



utilize a portion of the energy derived from nitrogen oxidation to



reduce 003, their primary source  of carbon.  The net result is a



reduction in the amount of oxygen actually consumed.  Short term



(0-5 day) experiments,18'19'20 employing cultures of Nitrosomonas



and Nitrobacter have related the  depletion of oxygen to the production



of nitrite and nitrate with the corresponding 0/N ratios of 3.22 and



1.11 determined.  However in long term experiments, the decay of



these  organisms would be expected to exert an oxygen demand approximately



equivalent to the oxygen originally  generated, resulting in an overall


                                              21
relation  not  significantly different from 4.57

-------
                                                                    31
     In Table #5, NC^g derived from long term incubation of river

samples was compared to a predicted value based upon 4.57 x TKN-N

initially assayed in the sample.  A paired t-test established, at

a 95% confidence level, that no significant difference existed

between these methods of prediction with t=.7' at 57 degrees of freedom.

A plot of the predicted NOD (4.57 x TKN-N) vs that observed with

laboratory incubation is included in figure #9.  The comparison of

NOD and TKN x 4.57 vs RMI is included in figures #10 and #12 - #16.

The close correlation suggests that:

          1.  Nitrification was essentially completed after 20 days
              of laboratory incubation.

          2.  The inhibitor to nitrification employed, N-serve,
              gave accurate NOD results.

          3.  The NOD observed was due to autotrophic bacteria since
              the inhibitor was specific for Nitrosomonas.

     Figures #3-8 include the found NOD vs River Mile Index and

indicate that nitrification occurs within a short span of the river,

between Mains Point and Fort Washington.

     A second peak NOD area occurred, as with CBOD, at stations 8-A;

10 and 11 on August 3, 24, and 31.  This was thought to reflect the

nitrogen contribution associated with the decay of the algae present

at these stations.  A significant NOD lag time was observed in samples

obtained in the algal bloom area.

     The changes in N02, N03, and NH3 concentration with  RMI

for samples obtained on July 20 are included in figure #11.  They

illustrate the classical relation expected during the course of

-------
                                                                     32
TABLE # 5               NOD20 vs  (TKN-N  x  4.57)
Date Station
July 20 P-8
1
3
4
5
6
7
8-A
10
11
July 27 P-8
1
3
4
5
6
7
8-A
10
11
Aug. 3 P-8
1
3
4
5
RMI
0.0
3.4
7.6
10.0
12.1
15.2
18.4
24.3
30.6
38.0
0.0
3.4
7.6
10.0
12.1
15.2
18.4
24.3
30.6
38.0
0.0
3.4
7.6
10.0
12.1
NOD 20
2.2
2.3
4.4
6.2
11.0
11.1
4.0
3.6
3.0
2.6
1.4
1.5
2.6
5.3
5.6
6.8
5.5
3.8
2.4
3.6
LA
1.4
7.3
4.8
5.0
TKN
.741
.705
.821
2.05
2.495
2.20
1.358
1.074
.853
.621
.461
.380
.582
.986
1.212
1.301
.897
.727
.606
.509
.438
.358
1.477
1.262
1.298
NOD
(4. 57) (TKN)
3.4
3.2
3.8
9.4
11.4
10.1
6.2
4.9
3.9
2.8
2.1
1.7
2.7
4.5
5.5
5.9
4.1
3.3
2.8
2.3
2.00
1.6
6.7
5.8
5.9

-------
                                                                     33

TABLE # 5   (con't)       NOD20  vs  (TKN-N x 4.57)
 Date        S
Aug. 3 (con't)
Aug. 24
Aug. 31
:ation
6
7
8-A
10
11
P-8
1
3
4
5
6
7
8-A
10
11
P-8
1
3
4
5
6
7
RMI
15.2
18.4
24.3
30.6
38.0
0.0
3.4
7.6
10.0
12.1
15.2
18.4
24.3
30.6
38.0
0.0
3.4
7.6
10.0
12.1
15.2
18.4
NOD20
(TCMP)
3.3
4.4
4.0
3.8
1.8
3.0
2.7
4.0
4.4
3.4
4.1
3.5
6.6
6.8
4.2
1.6
1.2
7.1
4.7
5.1
4.9
4.3
TKN
1.083
.877
.734
.684
.546
.484
.484
.894
1.378
1.161
1.094
1.119
1.269
1.328
.802
.472
.400
1.760
1.392
1.264
1.092
.968
NOD
(4. 57) (TKN)
4.9
4.0
3.4
3.1
2.5
2.2
2.2
4.1
6.3
5.3
5.0
5.1
5.8
6.1
3.7
2.2
1.8
8.0
6.4
5.8
5.0
4.4

-------
                                                                     34

TABLE # 5  (con't)       NOD2Q  vs  (TKN-N x 4.57)
Date
Aug. 31 (con1


Sept. 8









3 = .0965
Sd = 1.1207
S3 = .1471
df = 57.00
t = 0.6560
Station
t)8-A
10
11
P-8
1
3
4
5
6
7
8 -A
10
11
RMI
24.3
30
38
0
3
7
10
12
15
18
24
30
38
.6
.0
.0
.4
.6
.0
.1
.2
.4
.3
.6
.0
NOD 20
(TCMP)
5.2
4
5
2
2
4
8
11
-
3
3
2
3
.9
.6
.0
.2
.5
.9
.0
-
.6
.0
.5
.0
TKN
1.224
1.28
.816
.460
.406
1.056
1.43 *
1.83 *
--
.721
.451
.288
.388
NOD
(4. 57) (TKN)
5.6
5
3
2
1
4
6
8

3
2
1
1
.5
.7
.1
.9
.8
.5
.4

.3
.1
.3
.8
n = 58




r = .
m = .
b = .

876
844
774





















* Not included in calculation of r or t
LA = lab accident

-------
        Figure #9
                                                                             35
             NOD2Q  (Inhibitor)  vs   NOD  (TKNx4.57) for River Water Samples
NOD
 (TKN x  4.57)
mg/1
  13 —
  12  -
  11  -
  10  _
   9  -
   7 -
   6 -
   5 -
   4 -
   3 -
   2 -
   1 -
n = 58
r = .876
m = .849
b = .774
           -i      i	1	1—-—i	1	r
            1     2     3     4     5      6      7
                                 -|	i	r
                                  10    11     12
                                 NOD  (Inhibitor)   mg/1

-------
                                                   STATION
                                                6        7
July 20, 1977
    8-A
                                                                       TKN-N  x  4.57
                                                                         NOD2o
                          10
                                                                    22    24    26    28    30    32    34    36    38
I   f   1   f   1   f   1
I   '   !
            I      1       1    »   1       1

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-------
                                                STATION
                                                                                July 27,  1977
P-8
I         I
                                     8-A
                                                                                              10



                                                                                              I
                                                                               11
                                                                           Tkn-N x 4.57   •
                                                                           NOD
                                                                              20
                                                                                          O
                                                                                                               •n
                                                                                                               ft
     l   f   l   I  I

-------
I   1    I   !   f   i    I    1   f   !   f   !   f   1   f   1    I   I   I   1   t   I    I   1   I   1    I   i
111!
                                                                                             August 3,  1977


                                                                                       8-A                 10
                                                                                  TKN-N  x 4.57
                                                                                                  O
                                                                                                                                   -n
                                                                                                                                   H-


                                                                                                                                  •s
                                                                                                                                   4
                                                                                                                                   CD

                                                                                                                                   =tt:
                                                                                                                                   t—'
                                                                                                                                   0-1
             2     4
  ID
                                                                RMI

-------
                                                    STATION
                                                                             August 24, 1977
P-8
                                                                           8-A
                                                                                              10
11
                                                                    TKN-N x 4.57    •

                                                                    NOD20           O
                                                                                                                   -n
                                                                                                                   p-
                                                                                                                   OP
       246
                                                      RMI
I   (   1   :   1   -   \
                                   i   i   i   1  i   '   i    r   i

-------
I  I   I

      P-8
                     1   ?
f  1


 3
f  1


  4
f  1   f
1   fill
     STATION

 6         7

 I          I
r  i
                                                                                  I    i   s
                                           August 31, 1977

                                        8-A                10
                                                                       TKN-N x 4.57
                                                                       NOD20
                                                                                                                              11
                                                                                             T)
                                                                                             H-



                                                                                             0)

                                                                                             =tt=

                                                                                             tn
                                                              RMI

-------
     P-8
   12 „
mg/1
   11 _

   10 -

    9 -

    8 -

    7 -

    6 _

    5 -

    4 -

    3 -
   1 -
     STATION
6         7
I         I
  September 8,  1977
8-A                10
 I                   t
                      TKN-N x 4.57
                      NOD
                         20
                       -1-
                        6
	1—
   18
   RMI
 1   I   1
                           "T~
                           24
                ~T
                30
 11
                                                                 -rt
~r
 36
10    12     14     16
20    22
                                                                                    26     28
                                                                  32    34
   1   I   1   f  1   »   1   I  I   I  1   I   I   i  I

-------
                                                                    43



nitrification.  The NOD pattern for this slack run (figure #11) is


directly associated with a decrease in NH3 and a corresponding


increase in N02~ and NC>3~.

    5.  Nitrification Kinetics


     The kinetics of nitrification for river samples taken between


Hains Point and Ft. Washington, the peak area of nitrification


associated with the STP effluents, were found to be exclusively


first order.  The average ke of 0.14 day"1 was observed with a


correlation coefficient of 0.91 for n=25 (Table #6).  This k value is


consistent with the close correlation between NOD and TKN-N x 4.57,


since a ke of 0.14 day"1 predicts that 94% of the ultimate NOD will


be expressed after 20 days of incubation.  The value predicted by

                               o
the Dynamic Estuary Model (DEM)° for the deoxygenation constant of


NOD was 0.08 day"1.  The standard deviation of 0.02 for the NOD ke (Table #6)


was twice that  of  the CBOn rate constant and reflects the fragile and


sporadic nature of nitrification.

    6.  Nature and Distribution of NOD

     Bracketing the region of exponential NOD are the upper stations


at Chain and Key Bridges and lower stations from Gunston Cove to

Possum Point.  Occasionally these stations had poor correlation to

Thomas Plots.  The upper stations correspond to a region of low

NOD2f) levels with  an average of 2.0 ppm.  The lower stations correspond


to a region of  low NOD20 or algal blooms.  The data from these stations


was plotted as D.O. depletion vs time and two additional classes


of kinetics were observed (figure 17).  A two-stage or consecutive

-------
                                                                    44
TABLE # 6
           NOD RIVER
 DATE - STA
July 20 - P8
           1
           3
           4
           5
           6
           7
         8-A
          10
          11
July 27 -
Aug. 3
Aug. 24 -
  k!0
-.061
-.560
 .031
 .040
 .038
 .035

 .029
 .001
 .051
-0.178
 -.016
 5.19
 8.03
13.47
13.07

 4.71
65.45
 2.46
P8
1
3
4
5
6
7
8-A
10
11
1
3
4
5
6
7
8-A
10
11
P8
1
3
4
5
6
7
8-A
10
11
--
.107
.042
.058
--
.071
--
-.000
.102
.027
.103
.083
.094
.090
.024
.030
0.033
-.052
-.025
.015
-.022
0.076
0.089
0.053
0.045
0.030
0.023
0.009
0.002
--
1.49
3.47
5.93
—
7.36
._
-361.09
1.93
5.16
1.53
8.00
5.23
5.20
4.60
6.21
5.13
4.08
-1.02
5.56
-1.63
4.55
4.83
3.79
4.54
4.75
-4.08
-13.38
45.92
   r
 -.747
-2.39
  .83
  .784
  .966
  .942

  .875
  .048
  .871
                                                .897
                                                .700
                                                .992

                                                .991
CURVE (see figure #17)
 CODE
  S   Low NOD
  S
  E
  E
  E
  E
  E
  S
  E
                                        E
                                        E
                                        E
009
901
855
949
982
961
928
793
944
895
746
704
740
823
992
991
959
972
700
263
188
022
S
E
E
E
E
E
E
E
E
E
C
S
C
S
E
E
E
E
E
S
S
C
Low NOD
                                                                Low NOD
                                                                Low NOD
                                                                Algae  30Qppb

-------
                                                                    45
TABLE # 6  (con't)
                           NOD RIVER
 DATE - STA
Aug. 31 - P8
           1
           3
           4
           5
           6
           7
         8-A
          10
          11

Sept. 8-1
           3
           4
           5
           7
         8-A
          10
          11
                  k!0
                 .068

                 .077

                 .095
                 .043
                 .090
                 .073
                 .009
                 .014

                 .056
                 .077
                 .036
                 .063
                 .067
                 .054
                 .039
                 .011
 1.60

 7.81

 5.60
 5.41
 4.95
 5.63
15.59
 9.92

 -.22
 5.12
12.37
13.00
   79
   51
   73
-5.63
 r
.871

.964

.989
.900
.992
.935
.229
.487

.654
.997
.714
.925
.930
.981
.734
.305
CURVE (see figure #17)
 CODE
  E
  E
  E
  E
  E
  C
  c
  s
  E
  E
  E
  E
  E
  C
  S
Algae 200ppb
Low NOD
The average was limited to Mains Point to Fort Washington stations,
because these stations represented the primary area associated with
nitrification and the kinetics were limited to "E" Kinetics.

k1Q:  n = 25
      y = .059
      s.d. = .023

k  = .14
r:
n = 25
Y = .91
r = .09

-------
            Figure #17
NOD Depletion Curves
                                                                                46
 Oxygen
Depletion
  mg/1
                                    s-shaped
                                    (lag + exponential)
                                                              consecutive
                                                              (2 lags + exponential curves)
                                             time

-------
                                                                    47
pattern was observed in which exponential growth occurred after a lag




phase in each of two distinct processes.  This may involve the separation




of NH4+—»NC>2~ and NC>2~—^0?" ^^ a ^aS stage.  In the majority of



the "exceptional" NOD stations an S-shaped pattern was observed with




a lag time probably occurring for the Nitrosomonas conversion of NH^



to NC^".   Nitrosomonas is considered the weak link in nitrification.




All samples from the peak algal bloom period displayed a lag time




with a resultant poor correlation coefficient in Thomas Plots.  This




suggests that the action of heterotrophic bacteria was necessary




to liberate the required ammonia.




     A consequence of the lag-free first order NOD kinetics observed




for the majority of Potomac river samples is that the BODg contains a



significant NOD component.  The average NOD5/BOD5 observed during the




study (Table #7) was 0.33 (n=56).

-------
                                                                    48
TABLE # 7
NOD5/BOD5 and NOD2Q/BOD2Q
DATE - STA
July 20 - P8
1
3
4
5
6
7
8-A
10
11
July 27 - P8
1
3
4
5
6
7
8-A
10
11


NODs
0.2
0.4
1.4
2.2
4.6
4.6
0.8
1.2
0.7
1.4
	
1.0
1.1
3.1
2.8
4.6
	
1.6
1.4
1.7


TBOD5 NOD5/TBOD5
3.2 .063
3.4
6.6
4.8
9.0
9.9
5.0
5.2
4.5
5.2
	
2.8
4.1
5.4
5.8
8.6
	
4.7
4.4
3.6


.118
.212
.458
.511
.465
.160
.231
.156
.270
	
.357
.268
.574
.483
.535
	
.340
.318
.472
n = 56
y = .33
s = .18
NOD 20
2.2
2.3
4.4
6.2
11.0
11.1
4.0
3.6
3.0
2.3
1.4
1.5
2.6
5.3
5.6
6.8
5.5
6.8
2.4
3.6


TBOD2o *
7.2
8.3
12.6
12.1
18.6
20.8
11.9
9.8
9.2
9.5
5.4
5.0
7.7
9.4
10.7
14.9
14.4
10.2
7.5
8.2


IOD2o/TBOD;
.306
.278
.349
.512
.591
.534
.336
.367
.327
.242
.259
.30
.337
.564
.523
.456
.382
.666
.32
.439
n = 58
y = .38
s = .11

-------
                                                                    49
TABLE # 7  (con't)     NOD5/BOD5 and NOD20/BOD2o
 DATE - STA      NODs   TBODs NODs/TBODs    NOD2Q  TBOD2Q NOD20/TBOD20
Aug.  3 - P8
1
3
4
5
6
7
8 -A
10
11
Aug. 24 - P8
1
3
4
5
6
7
8-A
10
11
Aug. 31 - P8
1
3
4
0.9
5.6
3.7
3.1
0.9
1.6
1.3
1.1
0.3
0.9
0.4
2.9
3.4
1.8
2.1
0.9
0.4
0.0
0.5
0.7
0.9
6.0
4.7
3.2
8.6
7.4
6.3
4.4
5.2
5.2
4.3
3.2
4.0
3.0
5.1
7.0
7.0
6.4
5.5
8.0
6.6
3.3
2.8
3.3
9.2
8.5
.281
.651
.500
.492
.204
.308
.250
.256
.094
.225
.133
.569
.486
.257
.328
.164
.050
0
.152
.250
.273
.652
.553
1.4
7.3
4.8
5.0
3.3
4.4
4.0
3.8
1.8
3.0
2.7
4.0
4.4
3.4
4.1
3.5
6.6
6.8
4.2
1.6
1.2
7.1
4.7
5.5
12.4
11.4
10.2
8.6
10.9
11.8
10.2
8.0
8.8
7.0
8.2
10.1
12.0
12.1
12.9
22.0
24.1
13.2
5.4
5.5
12.8
11.2
.254
.589
.421
.490
.384
.404
.339
.372
.225
.341
.386
.488
.436
.283
.339
.271
.300
.282
.318
.296
.218
.555
.420

-------
                                                                    so




TABLE # 7  (con't]     NODs/BODs and NOD20/BOD20







 DATE - STA      NODs   TBOD5 NODs/TBODs    NOD20  TBOD2Q NOD20/TBOD20
Aug. 31 -
(con't)




Sept. 8 -









5
6
7
8 -A
10
11
P8
1
3
4
5
6
7
8 -A
10
11
3.
2.
3.
4.
2.
1.
0.
0.
2.
4.
7.
--
2.
1.
1.
0.
9
8
7
5
6
•7
0
1
8
6
0
-
0
8
0
5
-7
8
8
9
8
3
2
2
5
9
11
-
4
5
4
3
.6
.0
.8
.7
.9
.3
.0
.7
.3
.4
.8
--
.6
.0
.9
.6
.513
.350
.420
.464
.292
.515
0
.037
.528
.489
.593

.435
.360
.204
.139
5
4
4
5
4
5
2
2
4
8
11
-
3
3
2
3
.1
.9
.3
.2
.9
.6
.0
.2
.5
.9
.0
—
.6
.0
.5
.0
11
12
13
16
16
14
6
6
9
16
19
-
8
9
9
9
.8
.1
.5
.3
.8
.3
.5
.7
.5
. 3
.8
--
.1
.1
.8
.0
.432
.405
.318
.319
.292
.392
.308
.328
.474
.546
.556

.444
.330
.255
.333

-------
                                                                    51


V.    Oxygen Demand in the Potomac STP Effluent Samples


   A.  CBOD


    The CBOD kinetics observed for the sewage treatment plant effluents


were first order with an average ke = 0.17 (n=19, s=0.02)  and a average


correlation coefficient of 0.86 (Table #8).


   B.  NOD


    The NOD kinetics observed for the sewage treatment plant effluents


were all characterized by a lag period which generally lasted for the


first 10 to 15 days of incubation.  The NOD expressed within five days,


though relatively small compared to the NOD expressed after 10 to 12


days was significant and is included in Table #12.  The average (n=30)


NODs/BODs value was 0.26 with considerable noise in the data, s=0.21.


This relationship corresponded to an average CBODs/BODs ratio of 0.74.


The observed carbonaceous kinetics of ke = 0.17 dictated a CBOD ultimate


to CBODs ratio of 1.75 and together with the observed ratio suggests:


                     CBOD (ultimate) = BOD5 * 1-30


The relation CBOD ultimate = BODs x 1.45 is based upon the classical
kinetics, ke=.234  associated with sewage effluents and assumes an


insignificant nitrification contribution.  However, the factor 1.45


is not unsatisfactory for the Potomac STP effluents since it predicts


CBODuitimate values not significantly different from those predicted


by the 1.30 factor.  An STP effluent with a BODs of 30.0 rag/1 would


yield CBODult^mate values of 39.0 mg/1 based upon the 1.3 factor and


43.5 mg/1 based upon the 1.45 factor.  This is within the error

                            2
associated with the BOD test  and provides a conservative estimate of


the carbonaceous oxygen demand.

-------
TABLE # 8
CBOD - STP
                                                                   52
DATE - STA
July 20 - SI
S2
S3
S4
SB
S6
S7
S8
Aug. 24 - SI
S2
S3
S4
S5
S6
S7
S8
Aug. 31 - SI
S2
S3
S4
S5
S6
S7
S8
Name
Piscataway
Arlington
Blue Plains
Alexandria
West gate
Hunting Creek
Dogue Creek
Pohick Creek
Piscataway
Arlington
Blue Plains
Alexandria
Westgate
Hunting Creek
Dogue Creek
Pohick Creek
Piscataway
Arlington
Blue Plains
Alexandria
Westgate
Hunting Creek
Dogue Creek
Pohick Creek
kio
.105
.075
.076 *
.061
.074
.069
.050
.055
—
.101
.072
.092
*
.012
.064
.080
.037 *
--
.012*
.101
.101
--
--
.063
.076
LO
5.66
10.09
26.40
108.17
21.68
22.79
16.95
34.16
--
20.21
44.04
84.27
58.17
22.43
21.68
22.7
--
9.97
32.52
57.59
--
--
9.97
16.04
r
.997
.998
.844
.997
.991
.996
.983
.979
--
.998
.992
.992
.257
.998
.997
.621
--
.588
.997
.997
--
--
.976
.997
                                                                1 lag phase
                                                                 2  lag phases    —.
                                                                 2  lag  phases
                                                           588}  linear  r=.991
                                                                 m=.370  b=-.231,

-------
                                                                    53
TABLE # 8  (con't)
CBOD - STP
 DATE - STA
Sept. 8 - SI
A
SI
S2
S3
S4
S5
S6
S7
S8



Name
Piscataway
Arlington
Blue Plains
Alexandria
West gate
Hunting Creek
Dogue Creek
Pohick Creek



k10
.059*
—
--
.069
.047
.053
.034*
.007*

k:
n=19
k^.074
s=.020
L0
29.30
--
--
94.97
28.59
24.94
20.49
89.88


k~=.017
r
.019 1 lag phase
--
--
.985
.995
.989
.799 2 lags
.469} linear r=.991
m=1.294 b=.824
r :
n=26
f=.86
s=.26

-------
                                                                    54


    The Thomas correlation coefficients for NOD  are listed in Table #9.   The


negative correlation consistently observed resulted from the lag in


NOD.  The oxygen depletion plots (figures 18, 19 § 20) were restricted


to "S-shaped" and "consecutive S-shaped" patterns.


    The fraction of the potential NOD, TKN-N x 4.57, expressed after


20 days is included in Table #10.  The low recovery is related to


the long lag phase observed for the NOD.  Since the receiving waters


have lag-free, first order kinetics, it is likely that the consistent


NOD lag phase observed in STP samples is artifical and is perhaps


due to the lack of nitrifying bacteria.


   C.  Loading Characteristics


    The average flows and loadings based on:  CBOD2Q; TKN-N x 4.57 (NOD)


and BOD5 are presented in Table #11.  The ratio of NOD20 to BOD2o


for the STP effluents is compiled in Table #12 with an average value


of 0.69 (n=27; s=0.11).  The effluent loadings were therefore


predominantly NOD, and as pointed out previously, the river samples


were dominated by the CBOD.  The predominant nitrogen form, in the


STP effluents,  (nearly to the exclusion of all other oxidation states)


was ammonium  (Table #13).  This suggested that a portion of the


discharged ammonium was being lost  from the  system, since nitrification


would be expected to be very efficient  for ammonia.  A mechanism


for this loss  may be sorption of ammonia onto clays and organic

        22
colloids   in  sediments  and loss to the bottom by  sedimentation.   On


the bottom denitrification would be expected to predominate

-------
TABLE # 9  (con't)
NOD - STP
                                                                    55
 DATE - STA
July 20 - SI
Aug. 24 -
Aug. 31 - SI
DA
SI
S2
S3
S4
S5
S6
S7
S8
SI
S2
S3
S4
S5
S6
S7
SB
SI
S2
S3
S4
S5
S6
S7
S8
Name
Piscataway
Arlington
Blue Plains
Alexandria
Westgate
Hunting Creek
Dogue Creek
Pohick Creek
Piscataway
Arlington
Blue Plains
Alexandria
Westgate
Hunting Creek
Dogue Creek
Pohick Creek
Piscataway
Arlington
Blue Plains
Alexandria
Westgate
Hunting Creek
Dogue Creek
Pohick Creek
kio
-.005
- . 0464
-.089
-.024
-.034
-.064
-.014
-.063
-.025
-.089
-.098
-.098
-.076
-.050
-.082
-.066
	
	
-.004
-.063
-.051
-.012
.008
-.011
LO
-77.76
-5.68
-1.85
-30.13
-5.240
-3.35
-25.8
-2.59
-10.70
-.89
-.606
-.739
-1.43
-6.61
-.989
-2.09
	
	
-176.6
-3.98
-3.91
-4.46
109.17
-81.8
r
-.098
-.758
-.743
-.428
-.627
-.811
-.220
-.912
-.437
-.927
-.825
-.863
-.986
-.895
-.797
-.894
_ _ _
	
-.083
-.730
-.547
-.1058
.117
-.388
                                 Curve
                                 Type (see fig.20)
                              1 lag stage
                                                             1 lag stage
                                                             2 lag stages
                                                             2 lag stages
                                                             1 lag stage
                                                             2 lag stages
                                                             2 lag stages
                                                             1 lag stage
                                                             2 lag stages
                                                             1  lag stage
                                                             2  lag  stages

-------
                                                                    56

                                                                                 H
TABLE #_9_ (con't)             NOD - STP

                                                                                rti

                                                                Curve
 DATE - STA         Name           k10       L0       r         Type  (see fig.20)
Sept. 8 - SI    Piscataway       -.021    -24.59    -.526                       ""

          S2    Arlington         —       —      —
                                                                                •
          S3    Blue Plains

          S4    Alexandria       -.044    -14.30    -.899    2 lag  stages

          S5    Westgate         -.026    -13.44    -.406

          S6    Hunting Creek    -.027    -17.4     -.591    2 lag  stages       «

          S7    Dogue Creek      -.074     -2.38    -.689
                                                                                *
          S8    Pohick Creek     -.057     -6.89    -.897    2 lag  stages

-------
f   1   f   I   {   1    I   I    f    !    f
                    f   1    f
                             f   !    f   i   f   ]    f
                                                               i   1
                  Oxygen Depletion mg/1
        o
     ro
     cr\ -
  t-3
  s-
     00 -
     ro
     00
               O
vo
o
4s-
o
VJ1
O
 o\
 o
-1—
                            CQ
                            o  Co
                            (0  (V
                                                                                           ro-
                                                                                           cr\-
                                                                                           oo-
                                                                                           o -
                                                                                           ro
                                                                                           ro
                                                                                           o
                                                                    Oxygen Depletion  mg/1
                                                                                                                                       00
                                                                                                   (0  •

                                                                                                   CO  VoO
                                                                                                   H  I-1
                                                                                                                                       §
                                                                                                                                       J?
                                                                                                                                       0)
                                                                                                   CO
                                                                                                   ^
                                                                                                                                   M  O
                                                                                                                                   vo  a
                                                                                                                                       0)
                                                                                                                                       CO

-------
            Oxygen Depletion mg/1
                                       Oxygen Depletion mg/1
o
                                                            o
                                                           oo
                                                         o.
                                                           o\
                                                           00
                                                           ro
                                                           o
                                                                   o
                                                                          ro
                                                                          o
                                                   VJl
                                                   o
00
o
      o
                                                                                                                           da
                                                                                                                                 (D
                                                                                                                              IX)
                                                                                                                              o
                                                                                                                              oo
                                                                                       I
                                                                                       s
                                                                                       s?
                                                                                                                                 n>
                                                                                                                                 cf
                                                                                                                                 H-

                                                                                                                                 B
1   I  I
f  I   I   i   I   I

-------
                                                                                 59
            Figure #20
 Oxygen
?"*pletion
STP Oxygen Depletion Curves
                                      CBOD
                                                                         NOD (consecutive)

                                                                         2 lag phases
                                                                         NOD (exponential)

                                                                         1 lag phase
                                               time

-------
                                                                     60





TABLE* 10    Summary Sheet  of %  fNOD^n/NOD^ir\mate) for STP's


Station
Sl-Piscataway
S2-Arlington
S3-Blue Plains
S4-Alexandria
S5-Westgate
S6 -Hunting Creek
S7-Dogue Creek
S8-Pohick Creek


7/20
.747
.549
.873
.961
.24
.469
.214
.417


8/24
.85
.56
.78
.82
.61
.55
.41
.62


8/31
	
.52
.57
.68
	
	
.32
.53


9/8
.92
	
	
1.06
.40
.32
.42
.66

ave. ,
y
.84 ±
.54 ±
.74 ±
.88 ±
.42 ±
.45 ±
.34 ±
.56 ±
std.
dev.
s
.09
.02
.16
.17
.19
.12
.10
.11
                     NOD2Q = NOD determined with the inhibitor
                   *  NOn   .      - TK"M-M y 4 57
                     NUUultimate ~ 1KlN N x 4>;3/

-------
                                                                                61
        TABLE # 11
STP Loadings of CBOD2Q, NOD Ultimate, and BODs
       DATE - NAME
 July 20-Piscataway STP

        Arlington STP

        Blue Plains STP

        Alexandria STP

        Westgate STP

        Hunting Creek STP
aH
        Dogue Creek STP

        Pohick Creek STP

«n
 fuly 27-Piscataway STP
*rf
        Arlington STP
**

        Blue Plains STP

        Alexandria STP

"       Westgate STP

      •  Hunting Creek STP
Mb*
        Dogue Creek STP

        Pohick Creek STP


 oig.  3-Piscataway STP
M
        Arlington STP
i*%
„       Blue Plains STP

        Alexandria STP

"       Westgate STP

        Hunting Creek STP
wr
        Dogue Creek STP
•»
        Pohick Creek STP
Flow
(MGD)
12.48
21.00
280.00
19.40
11.63
3.90
2.28
14.26
16.00
19.90
251.00
19.73
11.51
3.75
2.28
13.79
7.50
20.20
261.00
19.09
11.15
4.17
2.16
14.18
20-day TKNx4.57=
CBOD Loading NOD
(mg/1) (Ib/day) (mg/1)
4.8 499.9 24.05
9.1 1,594.8 85.14
27.6 64,491.4 81.78
99.0 16,027.7 98.61
19.2 1,863.4 95.73
20.4 663.9 110.64
15.0 285.4 157.30
31.2 3,712.8 139.50
39.15
61.67
66.10
81.98
77.55
84.57
73.49
97.86
19.63
73.20
65.43
98.56
83.01
92.42
90.38
110.42
Loading
(Ib/day)
2,504.7
14,920.6
191,090.7
15,964.6
9,291.0
3,600.9
2,992.9
16,600.8
5,227.4
10,241.5
138,455.3
13,498.0
7,448.9
2,646.6
1,398.3
11,261.7
1,228.6
12,339.5
142,512.1
15,701.5
7,724.0
3,216.2
1,629.1
13,066.5
BOD 5
Loading
(Ib/day)
749.8
2,102.9
53,274.9
11,462.0
1,630.5
507.7
285.4
2,499.0
881.2
1,096.0
40,216.2
4,346.7
864.5
187.8
79.9
1,726.2
262.9
606.8
58,807.2
7,073.2
558.3
229.7
54.1
994.0

-------
        TABLE * 11  (con't)
       DATE - NAME
Aug. 24-Piscataway STP

        Arlington STP

        Blue Plains STP

        Alexandria STP

        Westgate STP

        Hunting Creek STP

        Dogue Cr-ek STP

        Pohick Creek STP


Aug. 31-Piscataway STP

        Arlington STP

        Blue Plains STP

        Alexandria STP

        Westgate STP

        Hunting Creek STP

        Dogue Creek STP

        Pohick Creek STP


Sept. 8-Piscataway STP

        Arlington STP

        Blue Plains STP

        Alexandria STP

        Westgate STP

        Hunting Creek STP

        Dogue Creek STP

        Pohick Creek STP

        * 18-dav BOD
                                            62
STP Loadings of CBOD2o> NOD Ultimate, and BODs
Flow
(MGD)
10.99
19.30
282.00
19.24
10.43
4.04
2.09
13.70
12.13
20.80
297.00
20.18
10.59
4.09
2.15
13.91
10.95
20.80
313.00
19.44
10.44
4.00
2.63
14.24
Loading
20 -day
CBOD'
Cmg/1)
0
17.4
39.6
75.6
23.4
20.0
19.5
16.2
--
7.2
28.2
49.8
15.6*
14.4*
9.0
14.4
12.0
15.6*
132.0*
84.6
25.4
21.0
18.0
27.9
(Ib/day)
Loading
(Ib/day)
0
2,802.5
93,192.0
12,138.4
2,036.7
674.3
340.1
1,852.1

1,249.7
69,892.7
8,386.4
1,378.6
491.5
161.5
1,671.5
1,096.6
2,707.8
344,781.9
13,724.6
2,212.9
701.0
595.1
3,315.5
TKNx4.57=
NOD
(mg/1)
22.52
97.31
76.71
99.99
90.44
94.64
95.41
48.46
20.84
55.20
67.64
85.92
77.51
87.74
79.34
100.90
33.36
37.07
77.44
82.58
102.15
107.92
103.80
115.74
= BOD (mg/1) x Flow
Loading
(Ib/day)
2,065.3
15,672.6
180,520.9
16,054.2
7,871.7
3,190.7
1,664.1
5,540.3
2,109.5
9,581.4
167,645.3
14,469.1
6,849.8
2,994.7
1,423.5
11,712.4
3,048.4
6,434.6
202,275.9
13,364.5
8,899.7
3,602.4
2,278.2
13,754.0
(MGD) x 2000
BOD5
Loading
(Ib/day)
27.5
2,415.9
57,890.9
8,959.1
1,357.8
505.7
230.2
1,714.9
0
208.3
69,892.7
6,971.8
1,537.7
512.0
495.2
2,577.0
1,069.1
2,707.8
344,781.9
11,193.6
1,672.7
560.8
322.6
1,853.8

                                                             239.66

-------
                                                                       63
TABLE # 12      Proportion of Total STP Demand Expressed as NOD
 DATE - STA
July 20 - SI
Aug. 24 -
Aug. 31 -
'A
SI
S2
S3
S4
S5
S6
S7
S8
SI
S2
S3
S4
S5
S6
S7
S8
SI
S2
S3
S4
S5
S6
S7
S8
NOD 5
3.0
6.0
1.8
14.4
3.6
2.4
7.2
3.6
0
1.2
0.6
2.4
1.8
3.6
0.6
1.8
-
0
6.0
1.8
2.4
0.6
22.8
12.4
BOD5 NOD5/BOD5
7.2 .42
12.0
22.8
70.8
16.8
15.6
15.0
21.0
0
15.0
24.6
55.8
15.6
15.0
13.2
15.0
-
1.2
28.2
41.4
17.4
15.0
27.6
22.2
.50
.079
.20
.21
.15
.48
.17
-
.080
.024
.043
.12
.24
.045
.12
-
0
.21
.044
.14
.040
.83
.56
NOD 20
18.0
46.7
71.4
94.8
28.8
51.9
33.6
58.2
19.2
54.6
60.0
82.2
55.8
52.2
39.0
30.0

31.2
38.4
58.8
-
-
27.6
55.8
BOD2Q I1
22.8
55.8
99.0
193.8
48.0
72.3
48.6
89.4
19.2
72.0
99.6
157.8
79.2
72.2
58.5
46.2

38.4
66.6
108.6
-
-
36.6
70.2
roD20/Bi
.789
.837
.721
.489
.600
.718
.691
.651
1
.758
.602
.521
.704
.723
.667
.649

.812
.576
.541


.754
.795

-------
                                                                         64
TABLE #12  (con't)     Proportion  of Total  STP  Demand  Expressed  as  NOD
DATE
Sept.










- STA
8 - SI
S2
S3
S4
S5
S6
S7
S8



NOD5
6.3
10.2
42.0
11.4
7.2
4.8
6.3
6.6



BOD5
11.7
15.6
132.0
69.0
19.2
16.8
14.7
15.6



NOD5/BOD5
.54
.65
.32
.17
.38
.29
.43
.42
n=30
x=.26
s=.21
NOD 20
42.0
-
-
87.6
41.2
34.8
44.0
76.5



BOD2Q r
54.0
-
-
172.2
66.6
55.8
62.4
104.4



TOD 2 Q/ BO
.778


.509
.619
.624
.705
.733
n=27
x=.69
s=.ll

-------
TABLE # 15     N02-N Concentration and the Resulting NOD Error         6S
""DATE/STA
•July 20
P-8
P-4
1
„, 1-A
**"* 2
- 3
4
5
*«. 5A
„»> 6
*"* 7
- 8
«w
8A
9
10
v~ 10B
^ 11
***=*
12
13
Vfetn*
14
w 15
»» ISA
*" 16
*" SI
S2
N03-N
Ong/D
N.D.
N.D.
N.D.
N.D.
N.D.
.174
.160
.162
.360
.535
.892
1.243
1.060
.893
.834
.618
.382
.164
.080
.144
.073
.046
N.D.
5.755
2.189
N02-N
(mg/D
N.D.
N.D.
N.D.
N.D.
N.D.
.107
.155
.222
.558
.606
.328
.126
.078
.055
.059
.063
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
.315
.241
1.14x
N02-N
N.D.
N.D.
N.D.
N.D.
N.D.
.1
.2
.2
.6
.7
.4
.1
.1
.1
.1
.1
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
.4
.3
NH3-N
Cmg/D
.087
N.D.
N.D.
N.D.
N.D.
.234
1.094
1.240
1.02
.800
.291
.186
.134
.071
.095
.092
.026
N.D.
N.D.
.128
.060
.094
.040
3.09
18.4
TKN-N
(mg/1)
.741
.621
.705
.632
.632
.821
2.052
2.495
2.429
2.200
1.358
1.179
1.074
.842
.853
.726
.621
.600
.453
.474
.863
.442
.621
5.263
18.631
4.57x
TKN-N
3.4
2.8
3.2
2.9
2.9
3.8
9.4
11.4
11.1
10.1
6.2
5.4
4.9
3.8
3.9
3.3
2.8
2.7
2.1
2.2
3.9
2.0
2.8
24.1
85.1
Error
N.D.
N.D.
N.D.
N.D.
N.D.
2.6
2.1
1.8
5.4
6.9
6.4
1.8
2.0
2.6
2.6
3.0
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
1.6
.4
STA
P-8
P-4
1
1-A
2
3
4
5
5A
6
7
8
8A
9
10
10B
11
12
13
14
15
ISA
16
SI
S2
RMI
0.0
1.9
3.4
4.9
5.9
7.6
10.0
12.1
13.6
15.2
18.4
22.3
24.3
26.9
30.6
34.0
38.0
42.5
45.8
52.4
58.6
62.8
67.4
STP
STP

-------
                                                                         66
TABLE # 13  (con't)     N02-N Concentration and the Resulting NOD Error
'E/STA
.y 20
S3
S4
S5

S6
S7
S8



N03-N
Cmg/1)
N.D.
N.D.
N.D.

1.557
.734
.048

N.D.
< .04
N02-N
Cmg/1)
N.D.
N.D.
N.D.

.213
.236
.044

N.D.
< .04
1.14x
N02-N
N.D.
N.D.
N.D.

.2
.3
.1



NH3-N
Cmg/1)
16.4
17.0
36.6

23.1
29.4
22.6

N.D.
< .02
TKN-N
Cmg/1)
17.894
21.578
20.941

24.210
34.420
30.525



4.57x
TKN-N
81.8
98.6
95.7

110.6
157.3
139.5



Error
N.D.
N.D.
N.D.

.2
.2
.1



STA
S3
S4
S5

S6
S7
S8



RMI
STP
STP
STP
t
STP ,
STP „„
STP '"
m
Vn


-------
                                                                    67


                              References

1.   "Standard Methods for the Examination of Water and Wastewater,"
    14th ed., APHA, 1975.

2.   Ballinger, D.  G.  and Lishka,  R.  J.,  "Reliability and Precision of
    BOD and COD Determinations."   J.W.P.C.F., p.  470-474,  (May 1962).

3.   Wang, L. K. and Wang, M.  H.,  "Computer Aided  Analysis  of Environmental
    Data Part II:   Biochemical Oxygen Demand Model," 22nd  Annual Proceedings
    Institute of Envir.  Science 1976.

4.   Benedict, A. H. "Temperature  Effects on BOD Stoichiometry,"
    J.W.P.C.F., 48, p. 864-5, 1976.

5.   Effects of Polluting Discharges  on the Thames Estuary, p.  202-225,
    Reports of the Thames Survey  Committee and of the Water Pollution
    Research Laboratory, Crown Copyright, 1964.

6.   Thomas, H. A., "Grophical Determination of B.O.D. Curve Constants,"
    Water and Sewage Works, p. 123-124,  (March 1950).

7.   Moore, W. E. and Thomas,  H. A.,  "Simplified Methods for Analysis
    of B.O.D. Data," Sewage and Industrial Works, 22, p. 1343-1355, 1950.

8.   Clark, L. J. and Jaworski, N. A., "Nutrient Transport  and Dissolved
    Oxygen Budget Studies in the  Potomac Estuary," Technical Report 37,
    AFO Region III, Environmental Protection Agency, 1972.

9.   Daniels, F. and Alberty,  R. A.,  Physical Chemistry, 4  ed., John
    Wiley and Sons, Inc., 1975.

10. Streeter, H. W. and Pheips, E. B., Public Health Bull., Wash..,
    No. 146, 1925.

11. Sawyer, C. N.  and McCarty, P. L., Chemistry for Sanitary Engineers,
    2nd ed., McGraw-Hill, 1967.

12. Breed, R. S.,  Murry E. G. D., and Hitchens, A. P., Sergey's
    Manual of Determinative Bacteriology, 6th ed., The Williams and
    Wilkens.

13. Srinath, E. G., Raymond,  L. C.,  Loehr, M. and Prakasam, T.B.S.,
    "Nitrifying Organism Concentration and Activity."  J.  of Env.
    Engineering, p. 449-463,  1976.

14. Mattern, E. K., Jr., "Growth  Kinetics of Nitrifying Microorganisms,"
    CE 756A6 prepared for Office  of Water Research and Technology.

15. Segel, I. H. Biochemical Calculations, John Wiley § Sons, Inc.,
    New York, 1968.

16. Finstein, M. S. et al, "Distribution of Autotrophic Nitrifying
    Bacteria in a  Polluted Stream;" The State Univ., New Brunswick,
    N. J. Water Resources, Res.  Inst. W7406834,  Feb.  74.

-------
                                                                    68

                .   '   "       References

17.  Hockenbury,  M.  R. , and Grady,  C.  R.  Jr.  "Inhibition of Nitrification
    Effects of Selected Organic Compounds,"  JWPCF,  p.  768-777,  (May 1977).

18.  Wezernak,  C. T. and Gannon J.  J., "Evaluation of Nitrification
    in Streams," J. Sanitary Engineering Div.,  Proc.  of .American
    Soc.  of Civil  Engineers, p. 883-895, (Oct.  1968).

19.  Wezernak,  C. T. and Gannon, J. J.,  "Oxygen-Nitrogen Relationships
    in Autotrophic Nitrification," Applied Microbiology, 15,  p.  1211-1215,       t
    (Sept.  1967).

20.  Montgomery,  H.  A.  C. and Borne, B.  J., "The Inhibition of
    Nitrification  in the BOD Test," J.  Proc. Inst.  Sew. Purif.,                  '
    p. 357-368,  1966.

21.  Young,  J.  C.,  "Chemical Methods for Nitrification Control,"  24th            t
    Industrial Waste Conference, Part II. Purdue University,
    pp. 1090-1102,  1967.

22.  Allen,  H.  E. and Kramer, J. R., Nutrients in Natural Waters,                *"
    Wiley-Interscience Publication, New York, 1972.                             i

23.  Van Kessel,  J.  F.  "Factors Affecting the  Denitrification Rate                **
    in Two  Water-Sediment Systems,"Water Research,  11, pp. 259-267,
    CJuly 1976).

24.  Goring, C. A., "Control of Nitrification by 2-Chloro-6-(Trichloro-          **
    methyl) Pyridine Soil Science, 93, p. 211-218,  (Jan. 1962).

25.  Mullison, W. R. and Norris, M. G., "A Review of Toxicological,              m>
    Residual and Environmental Effects of Nitrapyrin and Its                    w
    Metabolite, 6-Chloropicolinic Acid," Down to Earth, 32, p.  22-27,           ""
    (Summer 1976).                                                              m

26.  Redemann, C. T., Meikle, R. W. and Widofsky, J. G.," The Loss of             -
    2-Chloro-6(Trichloromethyl) Pyridine from Soil," J. Agriculture
    and Food Chemistry, 12, p. 207-209,  (May-June  1964).                         "*

27.  Young,  J. C.,   "Chemical Methods  for Nitrification Control," JWPCF,
    45, 4, p. 637-646,  (April  1973).                                             ~

28. Laskowski,  D.   A., O'Melia  E.  C., Griffith, J.  D. et al, "Effect of           *
    2-Chloro-6(Trichloromethyl) Pyridine and Its Hydrolysis Product
    6-Chloropicolinic Acid  on  Soil Microorganisms," J.  of Env.                   **
    Quality, 4, p. 412-417,  (July-Sept.  1975).                                   «.

29. Bundy, L. G.,  "Control  of  Nitrogen  Transformations,"  Ph.D.                   m
    Dissertation,  Iowa  State University,  1973.

-------
                                                                    69


                              Appendix

 A.  N-Serve/NOD Determinations

     The inhibitor incorporated was formula 2533 Nitrification

Inhibitor, a product of the Hach Chemical Company.  The product

consists of 2-chloro-6(trichloromethyl) pyridine known as TCMP or

N-Serve.  This compound is plated on a simple inorganic salt which

serves as a carrier and is soluble in water.  The Dow Chemical Company,

Midland, Michigan, markets this chemical under the name N-Serve as a
                             23,24,25,26
fertilizer additive.  Studies using N-Serve suggest that it acts as a

"biostat" at moderate concentrations to delay nitrification and aids

the retention of ammonia or urea fertilizers on crops by retarding the

conversion to the more highly leachable N03~.  Ideally TCMP is slowly

biodegraded to 6-chloropicolinic acid which leaves the fields in

their original state, with no further inhibition to nitrification.

This allows long term (20-30 day) NOD assays without significant
                                                 21,27               28
inhibitor contribution to the carbonaceous demand.  Extensive studies

were performed on the toxicity of this material, because of concern

for the environment.  These have revealed it to be very selective
                                                 21,27
and effective at stopping nitrification at 10 ppm.

     Although the mechanism of its action is still unclear, it is

restricted to Nitrosomonas.   This selectivity is an advantage in that

it stops the process of nitrification at ammonia with little or no
                         29
effect on urea hydrolysis, assuring an adequate nitrogen source for

the heterotrophic bacteria contributing to the CBOD.  The disadvantage

of this selectivity is that Nitrobacter are not inhibited and NC>2~ will

be oxidized to N03~.  This limitation generally represents a small error

-------
                                                                    70


since  NC>2~  is generally much smaller than  TKN  in river water and


the demand associated with the N02 initially present is    .  or one-
                                                        T" • ^ /

quarter that associated with the TKN initially in the sample.


     The Potomac intensive survey did not include the separate


determination of NC^ and NO,, but incorporated cadmium reduction


technique whereby the sum concentration of N02 plue NOj was determined.         ,


The initial run, however, was assayed for N02 separately to determine


the significance of the potential error associated with TCMP.  This             '
                                                                                *
data is compiled in Table #13 with a maximum potential error of 5 to 7%
                                                                                *
associated with the NOD determination of 3 out of a total of 23 river
                                                                                t

stations and 9 waste treatment effluents.  This error was not considered
                                                                                ft!

significant enough to justify the added time and cost involved in the           *


analysis of N02 throughout the course of this study.                            «*

                                                                                Mm
 B. Alternative Methods

                                                                                «K
     Several other alternate approaches to determining NOD were
                                                                                w&>*

considered.  In situ tests, where a segment of water is followed


and assayed for D.O. and states of nitrogen would give actual "river            ^


rates" for NOD and CBOD.  However; the flows of a large, complex, tidal         m


estuary are not adequately defined.  Even if the segment of water               *™


could be followed it is altered by diffusion and by the input of                **


effluents, resulting in a faulty estimate of the NOD rate.


     Laboratory studies involving the incubation of samples with
                                                                                 M**

analysis of sub-samples at timed intervals for all nitrogen  states,              ^


coupled with the determination of NOD based upon the stoichiometric              *»


relation between oxygen utilization and nitrogen oxidation  is a                  <•


second method  for NOD determinations.

-------
                                                                    71



     A second approach to laboratory studies involves only D.O. analyses,


not the extensive laboratory committment associated with frequent


N-series determination.  One such method involves killing all of the


bacteria present by pasteurization, chlorination, or acidification and


reseeding with populations containing few nitrifyers.  However, these


methods involve the disadvantages associated with extensive sample


modification.  A second D.O. method involves killing or inhibiting


the nitrifyers by addition of:   methylene blue;  thiourea; allylthiourea


ATU; and TCMP.  Methylene blue  interferes with Winkler D.O. determinations


as does thiourea.  Further,  only Temp has been found effective for


long term experiments, because  the others were either degraded thus


contributing to the CBOD or  Nitrosomonas quickly acclimated to their

                              21
effect and nitrification began.

-------
                                                                    72
TABLE #14
C.  Study Data
          Potomac River Long-Term BOD Survey Data-Summer 1977
Date:  7/20/77
Days of Incubation
STA #
P-8


P-4
1


1-A
2
3


4


5



T*
C*
N*
T
T
C
N
T
T
T
C
N
T
C
N
T
C
N
5
3.2
3.0
0.2
3.6
3.4
3.0
0.4
3.7
4.0
6.6
5.2
1.4
4.8
2.6
2.2
9.0
4.4
4.6
8
4.2
4.0
.2

4.9
4.0
0.9


7.7
5.2
2.5
9.7
4.4
5.3
12.8
5.5
7.3
11
5.6
4.3
1.3

6.1
4.6
1.5


8.3
5.2
3.1
11.0
5.1
5.9
14.1
6.5
7.6
15
6.8
4.6
2.2

7.4
5.2
2.2


10.8
7.6
3.2
11.7
5.5
6.2
17.1
7.0
10.1
18
7.0
4.8
2.2

8.0
5.8
2.2


11.2
8.0
3.2
12.0
.58
6.2
17.5
7.4
10.1
20
7.2
5.0
2.2

8.3
6.0
2.3


12.6
8.2
4.4
12.1
5.9
6.2
18.6
7.6
11.0
5-A T
6


7


T
C
N
T
C
N
8
9
5
4
5
4
0
.1
.9
. 3
.6
.0
.2
.8

11.4
5.0
6.4
8.0
5.5
2.5

11
5
6
9
6
3

.8
.0
.8
.8
.0
.8

17
8
8
11
7
3

.0
.6
.4
.1
. 3
.8

19
9
9
11
7
3

.3
.4
.9
.5
.7
.8

20.8
9.7
11.1
11.9
7.9
4.0
  5-A T
     C
     N
4.6

5.2
4.0
1.2
7.3
5.0
2.3
8.1
5.7
2.4
9.0
6.0
3.0
9.2
6.2
3.0
9.8
6.2
3.6
     *T  -  BOD  (mg/1)
     *C  -  CBOD  (mg/1)
     *N  -  NOD  (mg/1)

-------
                                                                     73
TABLE # 14   (con't)
Date:  7/20/77
10-B T
3.9
                             Days  of Incubation
STA #
9 T
10 T*
C*
N*
5
4.9
4.5
3.8
0.7
8

6.2
4.7
1.5
11

7.8
5.4
2.4
15

8.2
5.6
2.6
18

8.9
5.9
3.0
20

9.2
6.2
3.0
11


12
13
14
15
15-A
16
S-l


S-2


S-3


S-4


S-5


T
C
N
T
T
T
T
T
T
T
C
N
T
C
N
T
C
N
T
C
N
T
C
N
5
3
1
4
4
2
13
4
7
7
4
3
12
6
6
22
21
1
70
56
14
16
13
3
.2
.8
.4
.6
.5
.5
.2
.0
.8
.2
.2
.0
.0
.0
.0
.8
.0
.8
.8
.4
.4
.8
.2
.6
6
4
1






18
4
13
13
7
6
28
19
9
88
73
15
18
14
3
.1
.7
.4






.0
.6
.4
.8
.4
.4
.6
.0
.6
.0
.0
.0
.0
.4
.6
7.
5.
1.






20.
4.
15.
16.
8.
7.
55.
18.
37.
102.
83.
18.
25.
18.
7.
1
7
4






4
8
6
0
3
8
4
0
4
3
5
8
2
0
2
8.
6.
1.






22.
4.
18.
33.
8.
24.
66.
17.
49.
117.
94.
23.
26.
19.
7.
2
3
9






8
8
0
0
7
3
4
0
4
6
0
6
2
0
2
9.3
7.0
2.3






22.8
4.8
18.0
54.7
9.1
45.6
89.1
26.7
62.4
153.6
94.0
59.6
39.0
19.2
19.8
9.5
7.2
2.3






22.8
4.8
18.0
55.8
9.1
46.7
99.0
27.6
71.4
193.8
99.0
94.8
48.0
19.2
28.8
      *T - BOD  Qng/1)
      *C - CBOD  (mg/1)
      *N - NOD  (mg/1)

-------
TABLE # 14   (con't)                                                 74


Date:  7/20/77
Davs of Incubation
STA
S-6


S-7


S-8


#
T*
C*
N*
T
C
N
T
C
N
5
15.6
13.2
2.4
15.0
7.8
7.2
21.0
17.4
3.6
8
25.2
15.6
9.6
17.2
10.0
7.2
23.4
19.8
4.2
11
48.0
18.0
30.0
18.2
11.0
7.2
35.0
26.0
9.0
15
58.2
20.4
37.8
23.0
14.0
9.0
57.6
27.0
30.6
18
68.4
20.4
48.0
40.8
14.4
26.4
61.2
29.4
31.8
20
72.3
20.4
51.9
48.6
15.0
33.6
89.4
31.2
58.2
Date:  7/27'/77
STA #
P-8 T
C
N
2
.3
—
--
5
1.5
—
--
8
1.1
1.1
0
11
2.2
2.2
0
15
4.5
3.2
1.3
18
5.1
3.8
1.3
20
5.4
4.0
1.4
P-4  T        .7      2.2

  1  T       1.0      2.8      3.5      3.7      4.2      5.0       5.0
     C       1.0      1.8      2.5      2.7      3.2      3.5       3.5
     N       0.0      1.0      1.0      1.0      1.0      1.5       1.5

1-A  T       1.0      2.4

  2  T       1.2      2.2
T
C
N
T
C
N
T
C
N
2.1
1.6
0.5
2.4
1.0
1.4
2.1
1.5
0.6
4.1
3.0
1.1
5.4
2.3
3.1
5.8
3.0
2.8
5.6
3.8
1.8
6.8
3.2
3.6
6.8
3.8
3.0
6.6
4.4
2.2
7.8
3.5
4.3
7.7
--
--
7.3
4.8
2.5
8.8
3.8
5.0
8.9
4.7
4.2
7.7
5.1
2.6
9.4
4.1
5.3
9.8
4.9
4.9
7.7
5.1
2.6
9.4
4.1
5.3
10.7
5.1
5.6
5-A  T       3.3      7.5

  6  T       3.9      8.6     10.5     12.2     13.6      14.6      14.9
     C       1.7      4.0      5.5      6.5      7.2      8.0       8.9
     N       2.2      4.6      5.0      5.7      6.4      6.6       6.8

     *T - BOD Cmg/1)
     *C - CBOD (mg/1)
     *N - NOD (mg/1)

-------
TABLE #14  (con't)
                                                                     75
Date:  1121 111
Days of Incubation
STA #
7 T*
C*
N*
8 T
8-A T
C
N
9 T
10 T
C
N
10-B T
11 T
C
N
12 T
13 T
14 T
15 T
15-A T
16 T
S-l T
S-2 T
S-3 T
S-4 T
S-5 T
*T -
*C -
2
3.6
2.1
1.5
2.6
0.8
0.4
0.4
1.6
1.5
1.5
0.0
1.5
1.2
.6
.6
1.0
0.7
0.8
1.2
0.0
1.1
1.8
3.6
9.6
12.0
3.3
BOD (mg/1)
CBOn fmtJ/r
5
.51
--
—
5.6
4.7
3.1
1.6
4.2
4.4
3.0
1.4
3.7
3.6
1.9
1.7
2.7
2.2
1.9
3.4
1.2
2.6
6.6
6.6
19.2
26.4
9.0

)
8
5.7
3.0
2.7

7.6
3.8
3.8

5.0
3.6
1.4

4.0
2.3
1.7






10.8
11.2
22.8
32.4
15.6


11
7.5
4.2
3.3

8.7
4.9
3.8

6.0
4.6
1.4

5.6
3.2
2.4






16.2
11.2
25.8
32.4
15.6


15
9.6
5.6
4.0

9.0
5.2
3.8

6.1
4.7
1.4

7.2
3.8
3.4






27.0
12.0
45.6
32.4
15.6


18
11.8
6.3
5.5

9.8
6.0
3.8

6.4
5.0
1.4

8.0
4.4
3.6






28.2
13.2
57.6
32.4
17.4


20
14.4
8.9
5.5

10.2
6.4
3.8

7.5
5.1
2.4

8.2
4.6
3.6






28.8
13.2
72.0
32.4
18.6


     *N - NOD

-------
                                                                      76
TABLE #14  (con't)
Date:  7/27/77

STA #
S-6 T
S-7 T
S-8 T

2
5.4
2.4
7.8

5
6.0
4.2
15.0
Days of
8
12.0
12.0
21.6
Incubation
11
12.0
12.0
21.6
15
13.2
12.6
22.2
18
18.0
14.4
26.4
20
22.8
16.8
28.8
Date:  8/03/77
STA #
P-8  T

P-4  T
 2
1.3

1.4
 5
1.7

2.4
 8
1.7
 11
1.7
 15
1.7
 18
2.2
 20
2.4
1
1-A
2
3
4
5
5-A
6
7
T*
C*
N*
T
T
T
C
N
T
C
N
T
C
N
T
T
C
N
T
C
N
2.
1.
0.
2.
2.
3.
0.
2.
4.
1.
2.
4.
1.
2.
3.
2.
2.
0.
2.
1.
0.
2
3
9
6
9
2
5
7
1
9
2
2
5
7
8
6
0
6
3
5
8
3.2
2.3
0.9
4.2
4.0
8.6
3.0
5.6
7.4
3.7
3.7 '
6.3
3.2
3.1
6.4
4.4
3.5
0.9
5.2
3.6
1.6
4.4
3.3
1.1


9.4
3.8
5.6
8.5
4.8
3.7
7.5
4.1
3.4

6.2
4.6
1.6
8.0
5.0
3.0
4.6
3.5
1.1


10.4
4.5
5.9
9.4
5.7
3.7
8.3
4.9
3.4

6.9
5.0
1.9
9.0
5.5
3.5
4
3
1


11
4
7
10
5
4
10
5
4

7
5
2
9
5
4
.9
.6
.3


.9
.8
.1
.4
.8
.6
.0
.2
.8

.9
.3
.6
.9
.9
.0
5
3
1


12
5
7
10
6
4
10
5
4

8
5
2
10
6
4
.3
.9
.4


.4
.1
.3
.9
.1
.8
.0
.2
.8

.1
.3
.8
.8
.2
.4
5.5
4.1
1.4


12.4
5.1
7.3
11.4
6.6
4.8
10.2
5.2
5.0

8.6
5.3
3.3
10.9
6.5
4.4
      T - BOD (mg/1)
      C - CBOD (mg/1)
      N - NOD (mg/1)

-------
TABLE #14   (con't)
                                                                     77
Date:  8/03/77
                             Days of Incubation
STA
8
8-A


9
10


10-B
11


12
13
14
15
15-A
16
S-l
S-2
S-3
S-4
S-5
S-6
S-7
S-8
#
T
T*
C*
N*
T
T
C
N
T
T
C
N
T
T
T
T
T
T
T
T
T
T
T
T
T
T
2
2.9
3.0
2.2
0.8
3.2
2.0
1.6
0.4
1.7
1.8
1.7
0.1
1.6
0.5
1.2
1.3
1.0
1.4
4.2
3.6
18.6
31.8
6.0
0.6
3.0
8.4
5
5.3
5.2
3.9
1.3
5.4
4.3
3.2
1.1
3.8
3.2
2.9
0.3
2.9
1.3
1.3
1.9
0.8
1.6
4.2
3.6
27.0
44.4
6.0
6.6
3.0
8.4
8 11 15 18 20

7.4 8.8 10.6 11.1 11.8
5.4 6.3 6.8 7.1 7.8
2.0 2.5 3.8 4.0 4.0

7.0 7.8 9.1 9.7 10.2
4.5 5.3 5.6 6.0 6.4
2.5 2.5 3.5 3.7 3.8

4.8 5.9 6.6 7.2 8.0
4.0 4.7 5.3 5.4 6.2
0.8 1.2 1.3 1.8 1.8














*T - BOD (mg/1)
*C - CBOD (mg/1)
*N - NOD (mg/1)

-------
TABLE #14  (con't)
                                                                    78
Date:  8/24/77
STA #
P-8T*
     C*
     N*

P-4  T

  1  T
     C
     N

1-A  T

  2  T

  3  T
     C
     N

  4  T
     C
     N

  5  T
     C
     N

5-A  T

  6  T
     C
     N

  7  T
     C
     N

  8  T

8-A  T
     C
     N

  9  T
 2
2.0
1.6
0.4

1.3

1.8
1.6
0.2

1.7

1.5

2.6
1.4
1.2

3.6
2.0
1.6

3.3
2.6
0.7

3.6

3.4
2.6
0.8

3.1
2.3
0.8

1.5

2.3
2.3
 0

2.6
Days of Incubation
5
4.0
3.1
0.9
2.9
3.0
2.6
0.4
2.7
2.5
5.1
2.2
2.9
7.0
3.6
3.4
7.0
5.2
1.8
7.4
6.4
4.3
2.1
5.5
4.6
0.9
5.0
8.0
7.6
0.4
8
4.8
3.6
1.2

4.1
3.3
0.8


6.5
2.9
3.6
8.0
4.2
3.8
8.8
6.0
2.8

8.1
5.6
2.5
9.2
6.6
2.6

12.8
10.2
2.6
10
5.8
4.4
1.4

4.8
3.8
1.0


7.0
3.4
3.6
8.7
4.8
3.9
9.6
6.8
2.8

9.1
6.3
2.8
9.6
7.0
2.6

16.2
11.4
4.8
15
7.0
5.0
2.0

6.3
4.0
2.3


7.6
3.6
4.0
9.2
5.3
3.9
10.8
7.9
2.9

10.6
7.3
3.3
11.4
8.2
3.2

19.2
13.3
5.9
  18
 8.0
 5.4
 2.6
 6.6
 4.2
 2.4
 8.1
 4.1
 4.0

 9.9
 5.6
 4.3

11.4
 8.3
 3.1
11.6
 7.9
 3.7
12.4
 9.0
 3.4
                                                         21.4
                                                         15.1
                                                          6.3
                                                                    20
                                                                   8.8
                                                                   5.8
                                                                   3.0
                                                                   7.0
                                                                   4.3
                                                                   2.7
                                                                   8.2
                                                                   4.2
                                                                   4.0

                                                                  10.1
                                                                   5.7
                                                                   4.4

                                                                  12.0
                                                                   8.6
                                                                   3.4
                                                                  12.1
                                                                   8.0
                                                                   4.1

                                                                  12.9
                                                                   9.4
                                                                   3.5
          22.0
         15.4
          6.6
                      6.4
      *T - BOD  (mg/1)
      *C - CBOD  (mg/1)
      *N - NOD  (mg/1)

-------
TABLE # 14  (con't)
                                                                    79
Date:  8/24/77
STA #
 10  T*
     C*
     N*

10-B T

 11  T
     C
     N

 12  T

 13  T

 14  T

 15  T

15-A T

 16  T

S-l  T
     C
     N

S-2  T
     C
     N

S-3  T
     C
     N

S-4  T
     C
     N

S-5  T
     C
     N

S-6  T
     C
     N
  2
 3.0
 3.0
  0

 1.8

 1.2
 1.2
  0

 1.8

 0.9

 0.5

 0.8

 0.8

 1.1

  0
  0
  0

 8.1
 8.1
  0

13.8
13.8
  0

33.8
33.6
 0.2

 2.0
 2.0
  0

 7.8
 6.0
 1.8
5
6.6
6.6
0
3.0
3.3
2.8
0.5
3.0
1.6
1.4
1.0
1.2
1.3
0
0
0
15.0
13.8
1.2
24.6
24.0
0.6
55.8
53.4
2.4
15.6
13.8
1.8
15.0
11.4
3.6
Days of Incubation
8 10 15
13.6 17.3 20.9
12.2 14.1 15.7
1.4 3.2 5.2

4.7
3.8
0.9






4.2
0
4.2
19.6
16.0
3.6
35.4
29.4
6.0
71.4
61.2
10.2
18.0
13.8
4.2
27.6
15.0
12.6

6.5
5.6
0.9






13.2
0
13.2
26.6
17.0
9.6
47.2
34.0
13.2
80.2
70.0
10.2
22.2
13.8
8.4
33.8
17.0
16.8

10.2
7.7
2.5






18.6
0
18.6
66.0
17.4
48.6
88.8
39.6
49.2
106.2
72.6
33.6
45.6
22.2
23.4
57.0
19.2
37.8
   18
 23.1
 16.8
  6.3
 11.8
  8.6
  3.2
 19.2
   0
 19.2

 72.0
 17.4
 54.6

 94.8
 39.6
 55.2

138.6
 74.4
 64.2

 63.0
 22.8
 40.2

 64.4
 20.0
 44.4
   20
 24.1
 17.3
  6.8
 13.2
  9.0
  4.2
 19.2
   0
 19.2

 72.0
 17.4
 54.6

 99.6
 39.6
 60.0

157.8
 75.6
 82.2

 79.2
 23.4
 55.8

 72.2
 20.0
 52.2
     *T - BOD (mg/1)
     *C - CBOD (mg/1)
     *M - NOD (mg/1)

-------
TABLE #14  (con't)
                                                                     80
STA #
P-8 T
C
N
2
1.7
1.0
0.7
5
2.8
2.1
0.7
8
3.4
2.6
0.8
12
4.6
3.2
1.4
15
4.8
3.4
1.4
18
5.1
3.7
1.4
20
5.4
3.8
1.6
Date
STA
S-7


S-8


Date
STA
P-8


P-4
1


1-A
2
3


4


5


5-A
6


:
#
T*
C*
N*
T
C
N
:
#
T
C
N
T
T
C
N
T
T
T
C
N
T
C
N
T
C
N
T
T
C
N
8/24/77
2
7.6
7.0
0.6
2.6
2.0
0.6
8/31/77
2
1.7
1.0
0.7
2.1
1.2
1.2
0
2.7
1.9
2.4
0.5
1.9
4.7
1.9
2.8
3.8
1.6
2.2
3.8
3.8
3.0
0.8
                       5
                     13.2
                     12.6
                      0.6

                     15.0
                     13.2
                      1.8
Days of Incubation
    8       10       15
  22.6     29.0     44.4
  16.0     18.2     18.3
   6.6     10.8     26.1
  20.4
  13.2
   7.2
26.8
16.0
10.8
46.2
16.2
30.0
                      3.0

                      3.3
                      2.4
                      0.9

                      3.8

                      2.9
   3.8
   2.9
   0.9
 4.6
 3.7
 0.9
 4.9
 4.0
 0.9
                      6.7

                      8.0
                      5.2
                      2.8
   9.4
   6.3
   3.1
10.4
 6.9
 3.5
11.1
 7.2
 3.9
                   18
                  58
                  19
                  39.0
46.
16,
30.0
 4.9
 4.0
 0.9
11.4
 7.2
 4.2
                   20
                  58,
                  19,
                  39.0
46.
16.
30.0
 5.5
 4.3
 1.2
T
C
N
T
C
N
T
C
N
2.4
0.5
1.9
4.7
1.9
2.8
3.8
1.6
2.2
9.2
3.2
6.0
8.5
3.8
4.7
7.6
3.7
3.9
10.5
4.3
6.2
9.6
4.9
4.7
8.8
4.6
4.2
11.4
5.1
6.3
10.3
--
--
10.1
5.7
4.4
11.8
5.2
6.6
10.5
6.0
4.5
10.8
5.9
4.9
12.2
5.5
6.7
10.8
6.3
4.5
11.7
6.8
4.9
12.8
5.7
7.1
11.2
6.5
4.7
11.8
6.7
5.1
12.1
 7.2
 4.9
     *T - BOD  (mg/1)
     *C - CBOD  (mg/1)
     *N - NOD  (mg/1)

-------
                                                                    81
TABLE #14  (con't)
Date:  8/31/77

STA #         2        58        12       15       18       20
  7  T*      4.0      8.8     10.7     12.1     12.7     13.0     13.5
     C*      2.5      5.1      6.8      7.8      8.4      8.7      9.2
     N*      1.5      3.7      3.9      4.3      4.3      4.3      4.3

  8  T       3.7

8-A  T       4.0      9.7     11.7     13.6     14.9     15.5     16.3
     C       2.8      5.2      7.2      9.0     10.3     10.7     11.1
     N       1.2      4.5      4.5      4.6      4.6      4.8      5.2

  9  T       3.5

 10  T       3.3      8.9     11.2     13.7     15.0     16.0     16.8
     C       2.9      6.3      8.3     10.0     10.-     11.4     11.9
     N       0.4      2.6      2.9      3.7      4.3      4.6      4.9

10-B T       3.2

 11  T       3.3      6.3      7.5      9.9     11.7     13.3     14.3
     C       2.5      4.6      5.8      7.1      8.0      8.5      8.7
     N       0.8      1.7      1.7      2.8      3.7      4.8      5.6

 12  T       2.0

 13  T       1.4

 14  T       0.7

 15  T       0.9

15-A T       0.8

 16  T       1.3

S-l  T       0.6      1.2      3.0     30.6     32.2     36.6     38.4
     C       0.6      1.2      3.0      4.2      5.8      6.0      7.2
     N        0        0        0      26.4     26.4     30.6     31.

S-2  T      19.0     28.2     36.8     39.6     58.8     66.6     66.6
     C      13.0     22.2     26.0     27.0     28.2     28.2     28.2
     N       6.0      6.0     10.8     12.6     30.6     38.4     38.4
     *T - BOD (mg/1)
     *C - CBOD (mg/1)
     *N - NOD (mg/1)
Days of Incubation
5
8.8
5.1
3.7
9.4
9.7
5.2
4.5
9.1
8.9
6.3
2.6
7.9
6.3
4.6
1.7
4.2
2.8
1.7
1.6
1.8
2.6
1.2
1.2
0
28.2
22.2
6.0
8
10.7
6.8
3.9

11.7
7.2
4.5

11.2
8.3
2.9

7.5
5.8
1.7






3.0
3.0
0
36.8
26.0
10.8
12
12.1
7.8
4.3

13.6
9.0
4.6

13.7
10.0
3.7

9.9
7.1
2.8






30.6
4.2
26.4
39.6
27.0
12.6
15
12.7
8.4
4.3

14.9
10.3
4.6

15.0
10.-
4.3

11.7
8.0
3.7






32.2
5.8
26.4
58.8
28.2
30.6

-------
                                                                    82
TABLE #14  (con'tO
Date:  8/31/77
Days of Incubation
STA
S-3


S-4


S-5


S-6


S-7


S-8


#
T*
C*
N*
T
C
N
T
C
N
T
C
N
T
C
N
T
C
N
2
19.0
13.0
6.0
24.1
22.8
1.8
12.6,
10.2
2.4
1.2
0.6
0.6
4.8
3.0
1.8
4.8
4.8
0
5
28.2
22.2
6.0
41.4
39.6
1.8
17.4
15.0
2.4
15.0
14.4
0.6
27.6
4.8
22.8
22.2
9.8
12.4
8
36.8
26.0
10.8
67.0
46.6
20.4
18.8
15.6
2.4
15.0
14.4
0.6
28.8
6.0
22.8
32.2
11.2
21.0
12
39.6
27.0
12.6
67.2
48.0
19.2
31.6
15.6
16.0
15.0
14.4
0.6
31.2
7.8
23.4
34.9
13.5
21.4
15
58.8
28.2
30.6
91.2
49.8
41.4
45.0
15.6
29.4
19.2
14.4
4.8
36.6
9.0
27.6
60.0
14.0
46.0
18
66.6
28.2
38.4
107.6
49.8
57.8
52.8
15.6
37.2
19.2
14.4
4.8
36.6
9.0
27.6
69.6
14.4
55.2
20
66.6
28.2
38.4
108.6
49.8
58.8
55.8
__
--
19.2
—
--
36.6
9.0
27.6
70.2
14.4
55.8
Date:  9/08/77
STA #
P-8 T
C
N
3
1.4
1.4
0
5
2.0
2.0
0
7
3.0
2.6
0.4
10
4.0
'3.3
0.7
15
5.3
3.7
1.6
17
6.4
4.4
2.0
20
6.5
4.5
2.0
P-4  T       2.0      2.6

  1  T       2.2      2.7      3.5      5.0      5.8      6.5      6.7
     C       2.0      2.6      3.3      3.6      4.2      4.4      4.5
     N       0.2      0.1      0.2      1.4      1.6      2.1      2.2

1-A  T       1.2      1.8

  2  T       1.6      2.4

  3  T       3.9      5.3      7.0      8.0      8.7      9.1      9.5
     C       1.8      2.5      3.2      3.7      4.2      4.6      5.0
     N       2.1      2.8      3.8      4.3      4.5      4.5      4.5

     *T - BOD  (mg/1)
     *C - CBOD  (mg/1)
     *N - NOD  (mg/1)

-------
                                                                    83
TABLE #14  (con't)
Date:  9/08/77
                            Days of Incubation
STA #         3        5        7        10       15       17       20
  4  T*      5.5      9.4     13.5     14.6     15.4     16.1     16.3
     C*      3.7      4.8      5.8      6.2      6.8      7.1      7.4
     N*      1.8      4.6      7.7      8.4      8.6      9.0      8.9

  5  T       6.5     11.8     16.5     17.8     19.0     19.6     19.8
     C       3.1      4.8      5.9      6.8      8.0      8.4      8.8
     N       3.4      7.0     10.6     11.0     11.0     11.0     11.0

5-A  T       7.0     11.2

  6  T       4.9      6.6      8.2      9.4     10.3     11.4     11.6

  7  T       3.8      4.6      5.5      6.2      7.0      7.9      8.1
     C       1.9      2.6      3.4      3.8      3.8      4.3      4.5
     N       1.9      2.0      2.1      2.4      3.2      3.6      3.6

  8  T       3.5      4.7
8-A  T       3.6      5.0      6.2      6.9      8.0      8.8      9.1
     C       2.5      3.2      4.3      4.6      4.9      5.7      6.1
     N       1.1      1.8      1.9      2.3      3.1      3.1      3.0

  9  T       3.1      4.6

 10  T       1.8      4.9      5.8      7.2      8.6      9.6      9.8
     C       1.0      2.9      4.8      6.0      6.7      7.2      7.3
     N       0.8      1.0      1.0      1.2      1.9      2.4      2.5

10-B T       3.2      4.9
11


12
13
14
15
15-A
T
C
N
T
T
T
T
T
2.
1.
0.
2.
2.
1.
1.
0.
3
8
5
2
6
3
2
6
3
3
0
3
3
1
1
1
.6 4.7 7.2
.1 3.6 4.8
.5 1.1 2.4
.1
.4
.6
.8
.2
8.8 9.6 9.9
5.8 6.6 6.9
3.0 3.0 3.0





      T - BOD (mg/1)
      C - CBOD (mg/1)
      N - NOD (mg/1)

-------
                                                                    84
TABLE #14  (con't)
Date:  9/08/77
                            Davs of Incubation
STA
16
S-l


S-2


S-3


S-4


S-5


S-6


S-7


S-8


#
T
T*
C*
N*
T
C
N
T
C
N
T
C
N
T
C
N
T
C
N
T
C
N
T
C
N
3
1.3
1.0
1.0
0
9.6
5.4
4.2
102.0
102.0
0
31.0
31.0
0
8.2
8.2
0
7.0
7.0
0
5.1
4.5
0.6
4.2
4.2
0.0
5
1.7
11.7
5.4
6.3
15.6
5.4
10.2
132.0
90.0
42.0
69.0
57.6
11.4
19.2
12.0
7.2
16.8
12.0
4.8
14.7
8.4
6.3
15.6
9.0
6.6
7

17.1
6.0
11.1
15.6
5.4
10.2
132.0
90.0
42.0
79.6
67.2
12.4
22.2
15.0
7.2
24.0
15.0
9.0
16.2
8.4
7.8
17.4
9.6
7.8
10

26.6
9.9
16.7
41.4
6.0
35.4
183.0
111.0
72.0
98.6
76.4
22.2
25.2
18.0
7.2
43.2
17.4
25.8
37.8
8.4
29.4
40.2
13.2
27.0
15

26.6
9.9
16.7
69.0
--
--
220.0
--
--
131.0
80.0
51.0
33.6
22.2
11.4
47.8
21.4
26.4
51.0
12.6
38.4
65.4
18.7
46.7
17

53.4
11.1
42.3
72.0
--
--
264.
--
--
171.6
83.3
88.3
63.6
23.4
40.4
55.8
21.4
34.3
59.4
16.2
43.2
101.4
22.8
78.6
20

54.0
12.0
42.0
72.6
--
--
270.
--
--
172.2
84.6
87.6
66.6
25.4
41.2
55.8
21.0
34.8
62.4
18.0
44.0
104.4
27.9
76.5
      *T  -  BOD  (mg/1)
      *C  -  CBOD (mg/1)
      *N  -  NOD  9mg/l)

-------
                                     TECHNICAL REPORT DATA
                              (Please read Instructions on the reverse before completing)
  1. REPORT NO.
    EPA 903/9-79-003
                                                               :, RECIPIENTS ACCESSION NO.
1
4. TiTLE AND SUBTITLE
   CARBONACEOUS AND NITROGENOUS DEMAND STUDIES
   OF THE POTOMAC ESTUARY
5. REPORT DATE
   Summer  1977
6. PERFORMING ORGANIZATION CODE
   . AUTHOR(S)
    J.  L.  Slayton
    and E. R. Trovato
                                                               8. PERFORMING ORGANIZATION REPORT NO.
  9. PERFORMING ORGANIZATION NAME AIMO ADDRESS
 I  Annapolis Field Office,  Region III
"-"'  U.S.  Environmental  Protection Agency
    Annapolis Science Center
""j  Annapolis, Maryland  214.01	
                                                               10. PROGRAM ELEMENT NO.
                                                             11. CONTRACT/GRANT NO.
 |12. SPONSORING AGENCY NAME AND ADDRESS
    Same
                                                               13. TYPE OF REPORT AND PERIOD COVERED
                                                             14. SPONSORING AGENCY CODE

                                                                EPA/903/00
  ,15. SUPPLEMENTARY NOTES
  (16. ABSTRACT
  I
    The  biochemical oxygen  demand of Potomac  River and STP effluent samples was
    determined during the summer of 1977.  The fraction associated with N.O.D.
    was  measured using an inhibitor to nitrification and the  oxygen depletion
    v/as  monitored during long term incubation.  The average deoxygenation constants
    for  the river sample C.B.O.D. and N.O.D.  were 0.14 day"1  (kg).  The N.O.D. was
    found  to be a significant component of the B.O.D.c for STP  effluent and river
    samples.  The peak C.B.O.D. was associated with an algal  bloom of Oscillatcria.
  17.
                                   KEY WORDS AND DOCUMENT ANALYSIS
                     DESCRIPTORS
                                                  b.IDENTIFIERS/OPEN ENDED TERMS  C.  COSATI Field/Group
    Biochemical Oxygen Demand
    Nitrification
    Nitrification Inhibitor
    Respiration
                                                  Lag Tine
                                                  Depletion Curves
                                                  Deoxygenation
                                                    Kinetics
   18. DISTRIBUTION STATEMENT

    RELEASE TO  FJBLIC
                                                19. SECURITY CLASS (This Report)
                                                    UNCLASSIFIED	
               21. NO. OF PAGES
                   90
                                                20. SECURITY CLASS (This page}
                                                    UNCLASSIFIED
                                                                            22. PRICE
  EPA Form 2220-1 (C-73)

-------