NOVEMBER 1972
invironmental Protection Technology Series
Ammonia Removal in a
Physical-Chemical Wastewater
Treatment Process
I
55
UJ
Office of Research and Monitoring
U.S. Environmental Protection Agency
Washington, D.C. 20460
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Agency, have
been grouped into five series. These five broad
categories were'established to facilitate further
development and application of environmental
technology. Elimination of traditional grouping
was consciously planned to foster technology
transfer and a maximum interface in related
fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
H. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to"the ENVIRONMENTAL
PROTECTION TECHNOLOGY series. This series
describes research performed to develop and
demonstrate instrumentation, equipment and
methodology to repair or prevent environmental
degradation from point and non-point sources of
pollution. This work provider the new or improved
technology required for the control and treatment
of pollution sources to meet environmental quality
standards..
-------
EPA-R2-72-123
November 1972
AMMONIA REMOVAL IN A PHYSICAL-CHEMICAL
WASTEWATER TREATMENT PROCESS
By
Robert A. Barnes
Peter F. Atkins, Jr.
Dale A. Scherger
Contract No. 68-01-0049
Project 17010 HAM
Project Officer
Francis L. Evans III
Environmental Protection Agency
National Environmental Research Center
Cincinnati, Ohio 45268
Prepared for
OFFICE OF RESEARCH AND MONITORING
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price $1.25
-------
EPA Review Notice
This report has been reviewed by the Environmental
Protection Agency and approved for publication.
Approval does not signify that the contents necessarily
reflect the views and policies of the Environmental
Protection Agency, nor does mention of trade names or
commercial products constitute endorsement or recom-
mendation for use.
ii
-------
ABSTRACT
The pilot scale study at Owosso, Michigan, has demonstrated
the feasibility of using chlorination followed by dechlorination
with granular activated carbon for the removal of ammonia-
nitrogen in a physical-chemical treatment facility. The pilot
facility removed on the average 85 percent of the ammonia-
nitrogen applied to the chlorination-dechlorination system.
The study showed that ammonia-nitrogen removals as high as
98 percent can be obtained, if desired. The results from this
pilot operation indicate that there was complete removal of
free and combined chlorine in the dechlorination stage resulting
in a dechlorinated effluent. The following overall average
removal efficiencies were realized during the study: Ammonia-
nitrogen - 85 percent or better; organic-nitrogen - 90 percent;
biochemical oxygen demand - 94 to 96 percent; suspended solids -
90 percent; phosphorus - 80 percrnt or better.
This report was submitted by Ayres, Lewis, Norris, and May, Inc.,
Ann Arbor, Michigan, and Environmental Control Technology Corpor-
ation, Ann Arbor, Michigan, in fulfillment of Contract Number
68-01-0049 under the sponsorship of the Environmental Protection
Agency.
ill
-------
TABLE OF CONTENTS
Conclusions 1
Future Work 3
Introduction 5
Objectives 7
Methodology 9
Results 13
Discussion of Results 15
Acknowledgements 51
References 53
Appendix 55
-------
LIST OF FIGURES
Figure Title Page
1 Pilot Plant Flow Schematic 10
2 Daily Ammonia Removal During Test Period 18
3 Ammonia Levels Before and After Chlorination- 19
Dechlorination (3/3-3/4/71)
4 Ammonia Levels Before and After Chlorination- 20
Dechlorination 4/30-5/1/71)
5 Ammonia Levels Before and After Chlorination- 22
Dechlorination (5/13-5/14/71)
6 Ammonia Levels Before and After Chlorination- 23
Dechlorination (5/14-5/15/71)
7 Ammonia Levels Before and After Chlorination- 24
Dechlorination (5/15-5/16/71)
8 Per Cent Ammonia Removal Versus Chlorine 26
to Ammonia Feed Ratio
9 Ammonia Levels Before and After Chlorination- 28
Dechlorination (6/9-6/10/71)
10 Ammonia Levels Before and After Chlorination- 29
Dechlorination (6/12-6/13/71)
1L Ammonia Levels Before and After Chlorination- 30
Dechlorination (6/13-6/14/71)
12 Ammonia Levels Before and After Chlorination- 31
Dechlorination (6/14-6/15/71)
13 Per Cent Ammonia Removal versus Chlorine to 32
Ammonia Feed Ratio During Start-Up Period
vi
-------
14 Effects of Chlorination & Dechlorination 35
on Chloride Concentrations of Plant Effluent
15 Daily BOD Removal During Test Periad - 39
Phases I & II
16 Daily BOD Removal During Test Period - 42
Phase III
17 Daily COD Removal During Test Period - 43
Phases I & II
18 Daily COD Removal During Test Period - 44
Phase III
19 Daily Suspended Solids Removal During Test 45
Period - Phases I & II
20 Daily Suspended Solids Removal During Test 46
Period - Phase III
21 Daily Phosphate Removal During Test Period - 47
Phases I & II
22 Daily Phosphate Removal During Test 48
Period - Phase III
vii
-------
LIST OF TABLES
Table Title Page
I Ammonia Nitrogen Data 16,17
II Effect of Chlorination - 34
Dechlorination on Chloride
Concentrations
III Bacterial Removal in a Physical- 37
Chemical System Utilizing
Chlorination - Dechlorination
IV Organic Nitrogen Data 49
viii
-------
SECTION I
CONCLUSIONS
1. Ammonia^nitrogen can be removed to any desired level by
the chlorination^dechlorination system.
2. Complete removal of ammonia-nitrogen from the wastewater
would require a chlorine to ammonia-nitrogen feed rate of
approximately 9 to 1.
3. The chlorination-dechlorination system can remove free
chlorine and all forms of chloramines applied to the system.
4. There is an initial ammonia-nitrogen breakthrough during
start up of the dechlorination process which stops after a
brief lag or acclimation period.
5. The ammonia removal process tends to depress the pH in
non-buffered systems and might necessitate pH adjustments in
the final effluent.
6. The chloride content of the wastewater was increased, on
the average, from 193 mg/1 to 293 mg/1 when employing the
ammonia-nitrogen removal process.
7. Bacterial reductions in the ammonia-nitrogen removal
process exceeded the normal effluent requirements as set
forth by the State of Michigan. The chlorination-dechlorination
process also provided a dechlorinated effluent.
8. The pilot facility has demonstrated that the physical-
chemical treatment process can produce a final wastewater
effluent with a BOD concentration of 7 mg/1 and suspended
solids levels less than 20 mg/1.
9. The dissolved oxygen level of the final effluent varied
between 1 and 2 mg/1. Reaeration facilities would have to be
provided if greater dissolved oxygen levels were required.
10. The carbon dosage required in the organic removal stage
is approximately 500 pounds per million gallons of wastewater
treated.
11. Low lime treatment (150 to 175 mg/1 as Ca(OH)2) - pH
ranging between 8.8 and 9.4 - will, with proper coagulation
and sedimentation, reduce the phosphorus level of the waste-
water by over 80 per cent.
-------
SECTION II
FUTURE WORK
Based on the experience gained in this study together with
the results obtained, the following areas deserve further
investigation.
1. The exact mechanism of chloramine removal should be
defined.
2. The phenomena of acclimation noticed in the dechlorination
system is worthy of further study as it most probably will
add insight into the chloramine removal mechanism.
3. The composition of the effluent gases released during
chlorination and also during dechlorination should be evaluated.
4. The minimum amount of carbon (pounds per gallon of waste-
water treated) required in the dechlorination stage should be
more adequately defined.
5. The ability to reverse the roles of the two carbon systems
before regeneration should be investigated. That is to say,
can the exhausted dechlorination carbon (before regeneration)
be used in the organic removal phase or can the exhausted carbon
from the organic removal stage prior to its being regenerated
be used in the dechlorination stage.
6. A study should be initiated to determine whether the use
of activated carbon as a dechlorinating agent precludes its
subsequent use or reduces its effectiveness as an adsorbent
for water soluble organics even after regeneration.
7. The bacterial reductions observed during the study are
significant. A similar investigation into the ability of the
process to reduce viral pollution should be undertaken.
8. The chlorination-dechlorination system should be studied
operating under varying influent wastewater conditions of pH,
alkalinity and organic loading.
9. The chlorination-dechlorination system, i.e., breakpoint
chlorination followed by dechlorination using granular activated
carbon is unique from other systems in that the process can be
designed to remove all or part of the ammonia-nitrogen in the
wastewater. When intermediate removals of ammonia-nitrogen
(i.e., 50 to 75% removal) are required, the concept of split
treatment and the use of the non-chlorinated stream to effect
pH readjustment should be investigated.
10. The use of this ammonia removal system should be studied
after conventional biological treatment process. This would be
-------
of immediate benefit for biological treatment facilities
presently facing immediate or anticipated ammonia-nitrogen
removal orders.
11. The biological productivity of an effluent from a physical-
chemical treatment process incorporating this type of ammonia
removal system should be evaluated. These studies should be
compared to the productivity of effluents from conventional
biological systems, biological systems incorporating ammonia
conversion (to nitrates) and biological systems where sand
filtration is used as a tertiary step.
-------
SECTION III
INTRODUCTION
This report discusses in detail the operation and performance
of a pilot scale wastewater treatment facility utilizing
breakpoint chlorination followed by dechlorination with gran-
ular activated carbon for the removal of ammonia-nitrogen from
a domestic wastewater source. The study was performed at the
wastewater treatment facility of the City of Owosso, Michigan.
The chlorination-dechlorination process was operated in con-
junction with a complete physical-chemical wastewater pilot
treatment facility- The total treatment scheme involved a
number of chemical and physical processes operated in a
sequential manner as follows: chemical coagulation and sedi-
mentation, deep-bed filtration, carbon adsorption prior to
chlorination (pre-adsorption), breakpoint chlorination, carbon
adsorption for dechlorination (post-adsorption).
The main emphasis of this study was to evaluate the practical
feasibility of using breakpoint chlorination followed by
dechlorination using granular activated carbon for the removal
of ammonia-nitrogen from a domestic wastewater within a standard
physical-chemical treatment scheme. A secondary benefit of
the investigation was the collection of data on the effective-
ness of the overall process in removing biochemical oxygen
demand (BOD) , suspended solids (SS) and phosphates (PO^j) from
the Owosso raw wastewater. This data can then be added to the
data collected during a previous physical-chemical pilot scale
study performed at Owosso, Michigan, during the summer of 1970.
-------
SECTION IV
OBJECTIVES
The main objective of this study was to determine the
engineering feasibility of incorporating an ammonia-nitrogen
removal process into a conventional physical-chemical treat-
ment process. To accomplish this objective, consideration was
given to breakpoint chlorination followed by dechlorination
using granular activated carbon and also to partial chlorina-
tion (chlorine application below that required for breakpoint)
followed by chloramine removal by activated carbon.
The ammoniac-nitrogen removal system was evaluated in terms of
removal efficiency, chemical cost, process by-products and
operational efficiency to evaluate the optimum mode of
operation.
-------
SECTION V
METHODOLOGY
Pilot Treatment Facility
The basic pilot plant configuration is shown in Figure 1.
The pilot unit was a trailer mounted facility, completely
self-contained, leased from Hydromation Engineering Company
of Livonia, Michigan. The pilot unit received a raw waste-
water flow varying between 10 and 15 gallons per minute
(14,400 to 21,600 gallons per day) depending upon the deten-
tion desired in the sedimentation section. Once a flow rate
was established, a constant rate was maintained by a head
tank before the rapid mix chamber. In general, the unit was
operated at an.influent flow rate of 12 gallons per minute
(gpm),
The incoming raw wastewater was chemically coagulated with
lime (approximately 150 to 175 mg/1 as Ca(OH)2)- This yielded
a coagulation pH of 8.8 to 9.4. After chemical addition, the
wastewater was rapid mixed for one minute and then allowed
to slow mix for a period of 20 to 30 minutes. The coagulated
waste was then settled for approximately two hours. The effluent
from the coagulation-sedimentation section was then passed
through a Kinney strainer (continuous backwash) at a rate of
approximately 10 gpm, the remaining 2 gpm being wasted to
drain. The Kinney strainer was used to remove fibrous or lint-
like material which might cause surface loading of the deep-
bed filter. After the Kinney strainer, the wastewater was
filtered using a Hydromation deep-bed filter operating at a
flow rate of 10 gallons per minute per square foot (10 gpm/ft^).
The deep-bed filter had a bed depth (PVC Class I media) of
approximately 15 inches. The filter effluent was then pumped
through three 12-inch diameter (I.D.) carbon contactors at a
rate of six gallons per minute per square foot (6 gpm/ft^).
Each carbon contactor contained four feet of granular activated
carbon (Calgon Filtrasorb 400, 14 to 40 mesh) in repose. All
carbon contactors were operated under an up-flow, expanded-
bed mode. The effluent from the third carbon contactor was then
chlorinated using a Fischer and Porter vacuum-operated solution
feed gas dispenser. No make-up water was used in the chlorina-
tion process; hence,there was no dilution of the wastewater
as it underwent chlorination. The chlorinated wastewater was
allowed to contact for a period of 15 minutes before the de-
chlorination step. The dechlorination process consisted of two
12-inch diameter (I.D.) carbon contactors operating in a manner
analogous to the carbon contactors described earlier.
-------
PILOT PLANT FLOW SCHEMATIC
RAW SEWAGE (AFTER COARSE SCREENING )
*
A
RAPID AND SLOW MIX ( 1CHEMICAL JLIME
j. *
BACK WASH
RETURN
*
I
14
CHEMICAL COAGULATION
AND SEDIMENTATION
POLYMER APPLICATION
KINNEY STRAINER
DEEP BED
HIGH RATE FILTER
CHLORINE
CONTACT CHAMBER
EFFLUENT
PRE-ADSORPTION STAGE POST-ADSORPTION STAGE
(3- CARBON COLUMNS IN SERIES) ( 2- CARBON COLUMNS IN SERIES)
NOTE:
* * * * * *-
A,B,C,D,E,F- INDICATE SAMPLING POINTS
FIGURE I
10
-------
The pilot plant was operated continuously on a twenty-four
hour basis throughout the test period. Occasionly the system
was shut down for equipment repair, replacement of exhausted
carbon, or process modification as is normal when operating
any pilot installation. Samples were taken automatically at
selected locations every hour and composited based on flow to
yield twenty-four hour composites. As indicated in Figure 1,
samples were taken of the raw wastewater, Kinney strainer
effluent, deep-bed filter effluent, after 15 minutes carbon
contact (3rd carbon column effluent), chlorine contact chamber
effluent, and the final effluent (25 minutes carbon contact -
5th carbon column effluent). Throughout most of the study the
raw wastewater samples were taken by the Owosso treatment plant
personnel because automatic monitoring of the raw wastewater
in the pilot unit was prevented due to clogging of the auto-
matic valves.
Twenty-four Hour Surveys
Periodically throughout the test period twenty-four hour
continuous surveys were performed specifically to evaluate the
ammonia removal process. During these surveys (totaling nine
in number) grab samples were taken at the following locations:
before chlorination (after either the second or third carbon
contactor), after the chlorine contact chamber (15 minutes
contact time), and after dechlorination (after either the
fourth or fifth carbon contactor). These grab samples were
taken in such a manner (sequential time samples) as to measure
a particular mass (plug) of wastewater as it traveled through
the various unit processes. All grab samples were analyzed
immediately on site.
Samples taken before chlorination were analyzed for pH, ammonia-
nitrogen and chlorides. The samples taken after the chlorine
contact chamber were analyzed for pH, free chlorine, mono-
chloramihe,~dichloramine, trichloramine and ammonia-nitrogen.
Samples taken after carbon dechlorination were analyzed for
pH, chlorides, ammonia-nitrogen, free chlorine, monochloramine,
dichloramine, and trichloramine. On four survey days samples
were also collected for bacteriological analyses to determine
the magnitude of disinfection that might reasonably .be expected
from such a process.
Analytical Methods
All physical, chemical and bacteriological analyses performed
during this study were in accordance with Standard Methods-*-.
11
-------
Free chlorine, monochloramine, dichloramine, and trichloramine
were analyzed according to the procedure outlined by Palin2.
It should be noted at this point that the determination of
ammonia-nitrogen in the wastewater from the chlorine contact
chamber is exceedingly difficult because of the inherent inter-
ferences (presence of chloramines) and at best is only of
marginal value in assessing the quantitative amounts of
unreacted ammonia-nitrogen present.
12
-------
SECTION VI
RESULTS
Ammonia-^Nitrogen Removal
The ammonia-nitrogen removal data collected throughout the
study are tabulated in Table I and depicted graphically in
Figure 2. In addition to these results are ammonia-nitrogen
removal data generated by the twenty-four hour surveys which
were performed to evaluate more stringently the chlorination-
dechlorination process. These results are shown in Figures 3
through 13. The results on the chloride, ammonia-nitrogen,
pH, free chlorine, monochloramine,; dichloramine, and trichlora-
mine levels for these surveys are tabulated in Appendix A
(Tables A-l to A-10). Chloride levels in the raw wastewater
and final plant effluent at various times during some of the
twenty-four hour survey periods are shown in Table II and
Figure 14. The results obtained on bacteria reduction through-
out the pilot facility during four twenty-four hour survey
days are shown in Table III.
Overall Plant Performance
Figures 15 through 22 show the biochemical oxygen demand
(BOD) , chemical oxygen demand .(COD) , suspended solids (SS) ,
and phosphate (PO^) removal results obtained during the study.
Table IV gives the results of organic nitrogen removal obtained
during the testing program.
13
-------
SECTION VII
DISCUSSION OF RESULTS
Ammonia-Nitrogen Removal
A review of Table I and Figure 2 shows that the chlorination-
dechlorination process removed, on the average, 85 per cent
of the ammonia-nitrogen applied to the system. The average
level of ammonia-nitrogen in the wastewater prior to chlorina-
tion was 12.0 mg/1 and the average effluent concentration from
the pilot unit was 1.8 mg/1. This removal was accomplished
using a mean chlorine feed rate of approximately 6.5 pounds
per day (Ibs./day) applied to a continuous wastewater flow of
5 gallons per minute (7200 gallons per day). Use of these mean
values yields an average chlorine to incoming ammonia-nitrogen
feed ratio of 108 mg/1 to 12.0 mg/1 respectively (a 9 to 1
ratio by weight).
The use of total averages serves no purpose other than being
a gross method of analyzing data. A more realistic approach
to evaluating the data is to examine the twenty-four hour
survey data as shown in Figures 3 through 13.
A review of Figures 3 through 13 shows that the efficiency of
the chlorination-dechlorination process in removing ammonia-
nitrogen is directly proportional to the chlorine to ammonia-
nitrogen feed ratio. The pilot facility at Owosso was operated
using a constant chlorine feed, since the chlorine feed levels
could only be altered manually. Therefore, the ratio of chlorine
to ammonia-nitrogen varied depending on the incoming ammonia-
nitrogen concentrations. Thus, there were times when the process
was under-chlorinating, while at other times over-chlorination
was taking place. If the process was under-chlorinating (below
a certain optimum levelto be discussed later), then a certain
portion of the ammonia-nitrogen in the incoming wastewater
would be unreacted (not going off as nitrogen gas nor formed
into one of the chloramines) and would pass through the de-
chlorination section and be recorded in the final plant efflu-
ent. Thus, any variation in the chlorine to ammonia-nitrogen
feed ratios would be reflected by varying ammonia-nitrogen
removal efficiencies in the overall process.
The dependency of ammonia-nitrogen removal on the chlorine to
ammonia-nitrogen feed ratio is shown quite clearly in Figures
3 and 4. In Figure 3, at 10:00 AM the chlorine to ammonia-
nitrogen feed ratio was approximately 7.5 to 1 and resulted in
an ammonia-nitrogen level in the effluent of 0.7 mg/1 or 91
15
-------
CTl
Table I
Ammonia Nitrogen Data
Ammonia Nitrogen - mg/1
Cumulative
Throughput
Volume
(gallons)
0
21,092
28,000
42,100
49,080
56,041
63,272
70,722
76,826
84,600
90,817
97,789
105,094
111,106
131,834
138,093
153,502
160,819
166,392
176,814
181,683
185,072
189,441
195,423
201,923
208,403
214,836
221,834
Raw
15.6
15.5
After
Filtration
5.
14.
15.
,9
,3
9
14.0
12.7
15.7
13.
13.
2.
7.
9.
8.
12.
10.
9.
11.
9.
13-
13.
9.
14.
15.
14.
7
4
7
5
4
9
-
8
5
-
4
6
6
1
0
9
0
8
0
12.
13.
18.
13.
5.
3.
8.
5.
9.
6.
9.
10.
5.
11.
7.
7.
8.
8.
9.
8
3
0
3
6
6
1
9
6
.-
7
3
7
-
9
2
-
3
-
4
4
5
7
Before After
Chlorination Chlorination-Dechlorination
(15 minute (15 min. -chlorine contact)
carbon contact) (10 min. -dechlorination contact) Remarks
13.2
14.0
15.5
13
12
14
13
13
5
3
T^
5
10
11
6
6
7
11
8
7
9
7
8
8
9
.4
.7
.0
.7
.4
.5
.0
r
.6
.5
.0
.9
.3
.0
.6
.7
.6
.1
.2
.6
.8
.1
7
4
7
1
2
4
2
0
0
0
0
0
-
3
1
1
1
0
0
0
3
2
10
1
0
0
0
.1
.8
.0
.9
.8
.5
.2
.4
.25
.0
.0
.3
.9
.4
.1
.2
.8
.4
.6
.3
.9
.0
.4
.5
.4
.3
Cl2feed =
II
Cl2feed =
7#/day=
4#/day=
C^feed =
7#/day=
4#/day=
Cl2feed =
^H
it
it
n
it
it
n
n
K
ii
Chlorinator
n
Chlorinator
Cl2feed =
ii
i
"
#4 /day
II
II
6 . 0 #/day
10 am to 10
10 pm to 10
6 . 0 #/day
10 am to 2
2 am to 10
7#/day
|i
II
II
II
II
11
II
II
II
II
Malfunction
ti
Off
7#/day
n
n
M
pm
am
am
am
-------
Table I (continued)
Ammonia Nitrogen Data
Ammonia Nitrogen - mg/1
Cumulative
Throughput
Volume
(gallons-)
229
235
260
267
274
281
288
295
316
323
330
337
344
350
357
364
371
378
385
455
462
469
483
490
,286
,269
,930
,842
,754
,666
,578
,490
,266
',138
,050
,025
,000
,975
,948
,921
,894
,867
,840
,714
,708
,702
,675
,654
Average
Notes :
Raw
15.8
15.0
15.4
14.1
14.6
14.0
14.7
15.4
17.0
14.0
19.0
17.2
14.4
14.9
13.3
*Values
Before Chlorination After Chlorination-Dechlorination
After (15 minute (15 min. -chlorine contact)
Filtration carbon contact) (10 min.-dechlorination contact)
10
12
13
15
13
16
14
18
14
14
14
14
11
.5
.7
.8
.1
.2
.1
.4
.3
.8
.7
.0
.8
.3
not included in
10.
15.
13.
14.
14.
14.
16.
14.
18.
15.
14.
13.
12.
14.
18.
15.
14.
14.
17.
12.
column
6
-
-
-
2
0
1
3
7
0
6
0
5
4
4
0
9
0
8
1
9
1
0
average
0.
0.
10.
13.
2.
0.
3.
2.
0.
0.
3.
2.
4.
0.
0.
1.
1.
0.
0.
4.
6.
0.
0.
1.
1.
4
5
5*
1*
6
8
2
1
8
4
8
8
2
3
9
2
5
4
8
5
3
5
7
3
8**
Remarks
C12 feed = 7#/day
Chlorinator Off
ci2
C12
C12
ci2
ci2
ci*
ci2
^2
C12
Cl
£,
ci2
feed
feed
n
feed
feed
feed
feed
feed
feed
feed
11
feed
"
1
1
feed
feed
"
i
1
= 6 I/day
= 7#/day
II
= 6#/day
= 7t/day
= 8 if/day
= 5 1/ day
= 7 if/day
= 4 l/2#/day
= 10#/ day
"
= 8#/day
11
«i
"
= 7 1/ day
= 1 Oft/day
11
1
**Average effluent concentration over test period during variable chlorine feeds
-------
19
I 8
17
16
IS
14
13
12
I I
10
t
7
6
5
4
FIG. 2 - DAILY AMMONIA REMOVAL DURING TEST PERIOD
CARBW
V
v
ChLORIMATIOH
/VERAGE
- MFORf
CO
jrrtl: itfCAMM
133
i 5
>-
i
7
AH«*
MLOIM4ATIOH
I
7
A
*
60
IOO I4O \90 IEO 260
VOLUME THROUGHPUT - MLLONS X 10*
3OO 34O 380 4tO 4
900
-------
FIG. 3 - AMMONIA LEVELS BEFORE 8 AFTER CH LORI NAT I ON -
DCCHLORINATION
NON tPM 4PM 6PM
10PM MID
NIOHT
AM tAM 10AM
-------
FIG. 4 - AMMONIA LEVELS BEFORE 8 AFTER CHLORINATION - DECHLORINATION
CHLORINATION- DECH
NOON
2PM
4PM
6PM
8PM
10PM
MID
NIOHT
2AM
4AM 6AM
AM
10AM
-------
per cent removal efficiency. On the same day at 12:30 PM the
incoming ammonia^nitrogen level increased to 14 mg/1 and re-
sulted in a chlorine to ammonia-nitrogen feed ratio of 4.7 to
1 and resulted in an ammonia-nitrogen level in the effluent
of 5.7 mg/1 or only a 59 per cent removal efficiency. The direct
variation in ammonia-nitrogen removal efficiency with incoming
ammonia~nitrogen concentrations, because of the constant
chlorine feed rate, can be seen most vividly in Figure 4. Here
extreme variations in ammonia-nitrogen levels were observed
at two separate times. The chlorine feed rate on this parti-
cular survey day was fixed at 7 pounds per day. At a wastewater
flow rate of 5 gpm, this amounts to a chlorine dosage of 116
mg/1 in the wastewater. The 4:30 PM sample on this day showed
an incoming ammoniac-nitrogen concentration of 27.0 mg/1, result-
ing in a chlorine to ammonia-nitrogen feed ratio of 4.3 to 1.
The resulting concentration of ammonia-nitrogen in the plant
effluent was 12.0 mg/1, thus the process showed a removal
efficiency of about 55 per cent. At 10:00 PM on this same day
(Figure 4) the incoming ammonia-nitrogen concentration was
11.0 mg/1, thus making the chlorine to ammonia-nitrogen feed
ratio 10 to 1. This resulted in a plant effluent having an
ammonia-nitrogen level of 0.6 mg/1, and the process showed a
95 per cent level of efficiency.
The average incoming ammonia-nitrogen level for this particular
day (Figure 4) was 12.0 mg/1 with an average chlorine to
ammonia-nitrogen feed ratio of approximately 10 to 1. The
average ammonia-nitrogen removal was on the order of 75 per
cent. This low daily average ammonia-nitrogen removal was
caused by exceptionally high instantaneous ammonia-nitrogen
concentrations, where, because of the experimental arrangement
(constant chlorine feed), the wastewater was definitely being
underchlorinated, thus high ammonia-nitrogen levels were ob-
served in the plant effluent during these particular times.
Again, it should be pointed out that these data were obtained
from twenty-four hour composite samples which tend to mask the
true efficiency of the ammonia-nitrogen removal process when
a constant chlorine feed is being applied.
Figures 5, 6, and 7 show the results of a continuous monitoring
of the ammonia-nitrogen removal system over a seventy-two hour
period (May 13 through May 16, 1971). The results of these
particular surveys are most interesting because during these
three days the daily average ammonia-nitrogen levels were
essentially constant, varying between 14.1 and 14.7 mg/1. The
chlorine feed rate was varied on a daily basis between 5 and 8
pounds per day. When the chlorine feed rate was 7 pounds per
day (116 mg/1 chlorine) the pilot facility produced an average
effluent ammonia-nitrogen concentration of 0.8 mg/1 or 94 per
21
-------
FIG. 5 - AMMONIA LEVELS BEFORE ft AFTER CHLORINATION - DECHLORINATION
N)
to
1
17
1
1
1 4
1 1
1 t
1 1
1 0
t
7
*
M
i.
1
I
y
X
AVE
*~
*
/
RAGI
20'(
_ -
>-»>_,
; -i
AflE
"~- <
M r
ON
i
i
*
""
t
,_
X
^MMM
Q-
Cl r
AV
*
AF
__^
5GJ>M
FEED «
iRA
^>
FER
\
5E
*^
CH
fc^cr
r,
1
DAY
REMDVAIJ. 01
"
JOR
X<
NAT
'
'^"h"1
~ -~
^ '
BEI
ON
~ i
Nt
^ ^
i
~~~~
"ORE
- Di
AV
-\
3-r
*
'CA
-
CH
[CH
ERA
S
RBO
* -
.ORI
.OR
*'
4%
N
' .
NAT
NAT
0.8
'«M^ ^
owe
5/1
^ ^
^ (
ON
ON
ng/
i '
3SO
_ i
* »
L.
-X-
NOON 2PM 4PM SPM SPW 10PM *[° 2AM 4AM 6AM SAM
Ml
=_=
-.
-
,HIC
71
a*_
0AM
AN
-------
FIG. 6 - AMMONIA LEVELS BEFORE a AFTER CHLORINATION - DECHLORINATION
to
OJ
1 O
17
16
IS
14
13
12
1 1
10
9
8
6
4
S
2
o
/
V*
/
^~"
/"
^
^>*
.^
-i-
x--~
x^
x^
s"t^
k
^
^
'CAI
tBor
~-^
'N
-~Hr
Si
AF
~ ~5
X
->^
TEP
-t
0*
CJ2
AVE
Cl
-=:
4.9
FEE
RAO
-
ILOF
» '
GP.M
D=8
E F
AV
X
BE
\NK
*/[
EMC
:RA<
s
s
FOR
'\on
AY
VAL
>E :
^^^
E C
- 1
OF
14.
--v,
HLOI
"»1
owe
-N
3 ml/L
T
RINA
IECFJLOR
AVE
RAG
8'
noN
NAT
" r
sso
=^9
CAR
ION
'l5/|7l
r%
BON
0.4 itjfl/
/
*«^-
N
/
NOON 2AM 4AM
8AM 10AM MM)
NIGHT
2PM 4PM 6PM 8PM 10PM
-------
FIG. 7 -AMMONIA LEVELS BEFORE ft AFTER CHLORINATION - DECK LOR I NAT ION
1 6
1 7
1 «
1 9
1 4
1 9
1 2
1 1
1 0
9
6
7
6
5
4
»
9
«
tvt
DACI
'lv
p .
/
/
X
-
/
/
i
14 1
*,
/ >
\
ufl
X
\
)'CA
X
V
\
^80
X
'v
"V
i
S.
\,
\
\
0=1 5
Cll FE
AVJERA
I
r^^^
^v
X.
\
AF
«
V
\
PER
GPfc
ED
GE
^
f ^^^
CHI
1
U
= 51/CX
REMJOVA
J
^
^^^^
JORI
^^^
AVE
r^ i
4AT
kY
L 0
^**v<
B,
i
RAQ
~~^^.'
ON
F Nl
^
rCAI
irm
E =
f
-DE
I*3"
4L«
>r- /
It \
3.8
CHL
N *
ARB
!JJl_f
>ni_v
mgy
*
t- .
orar
OWQ
5/1!
74«
DN
~^-«
iDllLL
mm
IATI
5SO
- 5
k
MtC!
M6/
-"
ITlflr1
^1 IVJ
-x-
)N
11
.=:
1IGA
71
rx"
M
x^
NOON
2PM
4PM
6PM 8PM IOPM
Nt«HT
2AM 4AM 6AM 6AM 10AM
-------
cent removal efficiency (see Figure 5). Figure 6 shows the
results when the chlorine feed was increased to 8 pounds per
day. Here the average effluent concentration was lowered to
0.4 mg/1 for an overall ammonia-nitrogen removal efficiency
of 97 per cent. On the last day of this test period (May 16,
1971) , the chlorine feed rate was lowered to 5 pounds per day
(Figure 7). This lower chlorine feed rate produced an effluent
concentration of 3.8 mg/1 of ammonia-nitrogen and showed an
ammonia-nitrogen removal efficiency of 74 per cent.
Figure 8 is a summary plot of the data generated in the May 13
to 16, 1971, survey period (see Figures 5, 6, and 7). In this
figure the per cent ammonia-nitrogen removed by the chlorina-
tion-dechlorination process is plotted versus the chlorine to
ammonia-nitrogen feed ratio. This figure denotes in detail
the fact that varying percent removal of ammonia-nitrogen was
obtained as a function of the chlorine to ammonia-nitrogen feed
ratio. The actual pilot plant data compares quite well with
the experimental laboratory data as reported by Evans. The
only variation is that the field data indicates the need for
a slightly higher chlorine to ammonia-nitrogen feed ratio to
effect a given ammonia-nitrogen removal. Other data on chlor-
amine formation, chlorides, pH, etc., generated during these
three survey days are shown in Tables A-3 to Tables A-5 (see
Appendix A). A review of these Tables (A-3 to A-5) indicate
no breakthrough of free chlorine or chloramines during the
test period. The apparent breakthrough of a slight amount of
dichloramines will be discussed later in this report.
The data shown in Figures 5 through 8 were generated using the
wastewater after it had undergone phosphate precipitation using
low lime treatment (Ca(OH)2 dosage of 175 to 200 mg/1, resulting
in a pH of 8.8 to 9.4). Throughout the testing period no ad-
justment of pH or alkalinity was attempted. These data would
indicate for the Owosso waste that stringent control of pH and
alkalinity was not a prerequisite for ammonia-nitrogen removal.
The data also indicate that with the proper monitoring and con-
trol equipment, as would be found in full-scale operation, any
ammonia removal efficiency can be obtained if the chlorine feed
is paced properly with the influent ammonia concentration.
Tables A-l to A-10 indicate that chlorine addition depressed
the pH of the unbuffered, lime-clarified wastewater. Therefore,
pH adjustment will be required at Owosso to meet the effluent
pH requirement of 6.5 to 9.0. 1
It should be noted at this point that the dechlorination car-
bon employed during these survey days (May 13 to 16, 1971) was
the original carbon placed in the unit at the outset of the
study and exhibited no evidence of being exhausted (no free
chlorine or chloramine breakthrough) even after 410,000 gal-
lons of chlorinated wastewater had been applied to the system.
25
-------
FIG. 8 - PER CENT AMMONIA REMOVAL VERSUS CHLORINE TO AMMONIA FEED RATIO
IOO
90
80
I
£70
§60
50
7*
rrr
OH
X
-o
K-X
DATA
AS REPORTIO BY
EVAN!.
SURVIiY DAI A 5/
3-5/6/7
345
02 TO NH, - N RATIO
8
-------
After the May 16, 1971 survey day the original dechlorination
carbon (columns 4 and 5) was replaced by fresh carbon, and
an investigation was undertaken to analyze an ammonia-nitrogen
or chloramine breakthrough phenomena that has been observed
by other investigators4. The results from these studies are
shown in Figures 9 through 13. During this phase of the study,
there was continuous monitoring of the chlorination-dechlori-
nation system. Figures 9 through 12 show the ammonia-nitrogen
removals achieved by the chlorination-dechlorination process
during the initial days of operation using fresh dechlorination
carbon. Figure 13 is a summary graph of per cent ammonia-
nitrogen removal versus chlorine to ammonia-nitrogen feed
ratio for these initial days together with a summary curve of
previously discussed ammonia-nitrogen removal data obtained
with dechlorination carbon exposed to 410,000 gallons of
chlorinated wastewater.
As had been expected, Figure 13 indicates that the ammonia-
nitrogen removal in the initial phase of operation of the
dechlorination process is not as great as when the dechlori-
nation carbon had been exposed to free chlorine or chloramines
for a period of time (compare Curve A with Curve C). Curve B
indicates transition of the system to ammonia-nitrogen removal
levels approaching those shown in Curve C. Unfortunately,
Curve B (see Figures 10, 11, and 12) was generated using high
chlorine to ammonia-nitrogen ratios (9:1 and greater); hence,
the points cluster around high removal efficiencies. Although
the data are scattered, an inspection of Curves A, B, and C
at the 9:1 chlorine to ammonia-nitrogen feed ratio suggests
that there is substantial improvement in ammonia-nitrogen
removal efficiencies after the carbon has been exposed to a
chlorinated wastewater for a brief period of time. Thus,
a phenomena of acclimation (rather than one of continual break-
through) appears to be occurring. This observed acclimation
period explains the relatively inefficient ammonia-nitrogen
removals noticed at the outset of this study (see Table I),
and might possibly explain the low ammonia-nitrogen removals
reported by others^ using laboratory test systems. The accli-
mation period for the dechlorination carbon appears to be on
the order of three to five days under the test conditions
experienced at Owosso.
An hypothesis will now be proposed to explain this acclimation
phenomena, which if true, also defines the mechanisms by which
the chloramines are broken down on the surface of the activated
carbon. As is well known, the addition of near breakpoint doses
of chlorine to ammonia-containing wastewater results in the
reduction of the chlorine coupled with the oxidation of ammonia.
The products of the reactions consist primarily of molecular
nitrogen, various chloramines, chloride ions, and hydrated
protons. It is hypothesized that different dechlorination
27
-------
FIG. 9 - AMMONIA LEVELS BEFORE & AFTER CHLORINATION - DECHLORINATION
10
CO
29
23
21
1 9
IT
1 9
13
9
T
6
4
» 3
2
I
0
/
r
/
*
i
/8'
>
/
,--'
CAR
ir
/
^
JON
^
'\
\
\
<
20' (
\
\
i,^^^
ARE
A^.
Q =
CI2
AV
^""~- i
ON
^.
56
FEE
ERA
i __
PM
D
GE
=H
\
1
= 8* /D/
REM
^s
AF1
OVA
"^<
\,
'ER
Y
L N
XV C*
7*VE
»
CHI
3
KAu
^^^
AVI
^
.OR1
-N
__
=
^
OF"
Bt
.RA(
'"^-^
4ATI
= 7
(A J
O.\
^"^<
rnn
rUtr
iL =
.
DN-
5%
^" ITT^
Ep
U
4.b
t
DE
/i
/L.
j '
II r\t
1LUI
mg
;HLC
-
.
MMA
\iivn
'L.
F^
RIN
owe
6/9
I
/
XTIO
SSO
^
-*>
N
I0/
^,
,ma
M
X
1
M
X
NOON 2PM 4PM 6PM
8PM
10PM M|D
NI8HT
2AM
4AM «AM 8AM K)AM
-------
I 8
I 7
I 6
I 5
I 4
I 3
I 2
I I
I 0
9
FIG. 10- AMMONIA LEVELS BEFORE a AFTER CHLORINATION - DECHLORINATION
'
AVE
ft
RAGk =
w
6E
Q =
Cl?
AV
14.
Af
0
5 G
FEE
ERA
1 m^
TEF
rr
PM
D =
?E F
/L.
CH
«/L
10*
EM<
LOR
/D/
)VAL
NAT
Y
i
BEF
ON
96.!
\
\
ORE
-01
5%
8'
\
CHI
CHL
t
CAR
.ORI
ORfr
30N
__ '
ATK
ATIC
%
X
)N
IN
, ZO
X
£2
owe
6/1
S
pON
E=L
ssc
_
\
==-J
, Ml
5/1!
X"
CHIC
/7
AN
6 S
Z4
3
2
I
0
to
2PM 4PM 8PM 8PM K>PM
2AM 4AM 8AM SAM I
-------
U)
o
FIG. || - AMMONIA LEVELS BEFORE 8k AFTER CHLORINATION - DEC H LOR I NATION
17
16
19
14
13
It
II
10
9
2
I
0
/FTER CHLO«NATK»
\
NOON
2PM 4PM
MID
N(6HT
2AM 4AM 8AM
8AM
IOAM
-------
FIG. 12 - AMMONIA LEVELS BEFORE a AFTER CHLORINATION - DECHLORINATION
NOON 2PM 4PM «PM M tOPM MID 2AM 4AM 6AM SAM K>AM
NIGHT
-------
FIG. 13 - PER CENT AMMONIA REMOVAL VERSUS CHLORINE TO AMMONIA NITROGEN
U)
to
100
DURING 5TAR1T UF
Ut D kY AFTER START I IP FHI BH D -CHLO «NATI X
567
TO NHj - N RATIO
-------
reactions occur with respect to the chloramines, depending
upon whether they come in contact with fresh or "acclimated"
dechlorination carbon. When using fresh carbon, it is postu-
lated that some of the chloramines are reduced back to ammonia
while the carbon surface is oxidized. The hydrated protons
released from the carbon surface as a result of this oxidation
replace the chloride ions in the chloramines, resulting in
a reversion of the nitrogen portion of the chloramine back
to ammonia and release of chloride ions to solution. On the
other hand, when using an "acclimated" carbon, the carbon
surface is essentially devoid of available protons, which
eliminates the possibility of the reversion of the chloramine
back to ammonia. It is theorized in this case that the chlora-
mines are adsorbed and/or catalytically oxidized on the carbon
surface resulting primarily in the production of nitrogen gas,
chloride ions released to the aqueous phase, and a further
depression of the pH due to the release of hydrated protons
fro'm the breakdown of the chloramines.
Evidence to support this hypothesis is contained in the data
on ammonia removal in the fresh versus acclimated carbon
systems (Figure 13), the chloride mass balance data (Table II
and Figure 14), and the chloramine and pH data (Tables A-3,
A-5, and A^-8) for both the fresh versus acclimated carbon
systems.
As indicated previously (see Figure 13), there is a signifi-
cant difference in the ammonia-nitrogen removal efficiencies
when using fresh as compared to "acclimated" carbon in the
dechlorination phase. This effect is independent of the
chlorine to ammonia-nitrogen feed ratio in the chlorination
stage. On the other hand, Table II and Figure 14 show that
there is no significant difference in the chlorides released
to the aqueous phase when using either fresh or "acclimated"
carbon. These data were obtained during three consecutive
twenty-four hour surveys (May 13 to May 16, 1971) when accli-
mated dechlorination carbon was being used, and during one
twenty-four hour period (June 9 to June 10, 1971) when fresh
carbon was used for dechlorination. These results indicate
that the actual chloride concentrations measured during the
survey days agree quite closely with the calculated chloride
levels obtained from a theoretical mass balance, assuming all
of the chlorine is reduced to chloride ion. The range of
maximum and minimum values for the anticipated chloride con-
centrations was based on the accuracy with which the chlori-
nator could be set and held constant during the pilot operation.
The significant aspect of these results lies in the fact that
a reasonable chloride mass balance (95 per cent confidence
33
-------
TABLE II
EFFECT OF CHLORINATION-DECHLORINATION
ON CHLORIDE CONCENTRATIONS
OWOSSO, MICHIGAN
(1)
(2)
(3)
(4)
Anticipated Chloride
(5)
Actual Chloride
CO
*>.
Chloride Concentration Chlorine Concentration After
Date and Sample Prior to Chlorination Dosage Chlorination-Dechlorination
(mg/1) (mg/1) (mg/1)
4/30/71
A Acclimated Carbon
B " "
C
5/13-14/71
A Acclimated Carbon
B " "
C
D " -
E
F " "
5/14-15/71
A Acclimated Carbon
B
C
D
E " "
F
G " "
H
6/9-10/71
A Fresh Carbon
B
C " "
D " "
E " "
rji M II
156
148
140
180
190
200
195
220
215
300
265
200
175
180
185
180
265
200
510
365
260
220
200
112-136
112-136
112-136
110-132
110-132
110-132
110-132
110-132
110-132
123-149
123-149
123-149
123-149
123-149
123-149
123-149
123-149
121-147
121-147
121-147
121-147
121-147
121-147
268-292
260-284
252-276
290-312
300-322
310-332
305-327
330-352
325-347
423-449
388-414
323-349
298-324
303-329
308-334
303-329
388-414
321-347
631-657
486-512
381-407
341-367
321-347
Concentration After
Chlorination-Dechlorination
(mg/1)
280
260
250
320
325
330
320
355
350
450
415
350
325
330
345
335
425
340
655
510
405
370
345
Note: Column 2 and 5 from Tables A*-2, A-3, A-4
Column 3 from Figures 4,5, and 6
Column 4 -« Culuiim (2 -I- 3)
-------
FIG. 14
EFFECTS OF CHLORINATION 8 DECHLORINATION ON CHLORIDE
CONCENTRATIONS OF PLANT EFFLUENT
OWOSSO , MICHIGAN
900
460
wt
CHL(
/
<
, J
)RINE 0
MAXIMUM
CHLORIDE
/
OSAGE !
ANTICIPATI
CONCENT
<
'*/
IIO-I5C
;D
JATIONS
/
:/
'
-ACCLIM
(5/13-
~ FRESH
(6/9-
mg/L.
i y
^^ MINII
CHL(
ATED DECh
16/71 )
DECHLORir
10/71)
1' '/
'
IUM ANTIC
RIDE CONC
LORINATIOI
ATION CAR
/
/
'
IPATED
ENTRATIO*
i CARBON
JON
t
'
100 140 180 220 260 300 340 3tO
CHLORIDE CONCENTRATION - PRIOR TO CHLORINATION (mf/L.)
35
-------
limit). was attained even when the chlorine to ammonia-
nitrogen feed ratio was below that required for breakpoint
chlorination, in which case substantial amounts of chlora-
mines are generated. It is also significant that this same
phenomena occurs when fresh dechlorination carbon is
utilized, even though a certain proportion o"f the ammonia
is not removed by the chlorination-dechlorination process.
As is postulated and, apparently, supported by these data, once
the carbon surface has undergone essentially total oxida-
tion; the reversion of the chloramines to ammonia no
longer occurs. After an "acclimation" of the carbon surface,
the chloramine may be adsorbed and/or catalytically oxidized
on the carbon surface. In this case, the catalytic oxi-
dation of the chloramines release hydrated protons to the
aqueous phase resulting in a depression of the pH of the
wastewater during dechlorination. That this pH depression
actually does occur is observed in Tables A-3 through A-5
for "acclimated" dechlorination carbon. In this case the
pH of the effluent from the dechlorination system is on the
order of 1 to 2 units lower than the chlorinated wastewater.
Table A-8, for the case of fresh carbon in the dechlorination
phase, shows no such reduction in pH after passage of the
chlorinated wastewater through the dechlorination stage. In
this case the hydrated protons released from the carbon sur-
face are consumed in the reversion of chloramines to ammonia.
A more rigorous experimental testing programwhere all aqueous
and gaseous inputs and outputs are measuredwould be re-
quired to prove or disprove this hypothesis.
Table III shows the results of four bacteriological surveys
performed between June 9 and June 15, 1971. Samples were
taken every hour at various points and then composited into
six-hour composites. The bacteriological surveys covered a
twelve-hour period each day. Normally, the "A.M." labeled
samples were taken between 5 AM and 11 AM, while the "P.M."
samples were collected between 11 AM and 5 PM. Samples taken
after the chlorine contact chamber were dechlorinated using
sodium thiosulfate (8-10 mg/1 thiosulfate per mg/1 of free
or combined chlorine). All samples were refrigerated immediately
and transported under these conditions to the laboratory for
analyses. Table III shows that there is a substantial reduction
in total counts after chemical coagulation and sedimentation,
then slightly more removal after filtration and passage
through the first three carbon contactors. There is a signi-
ficant reduction after the chlorine contact chamber, as would
be expected. No total counts greater than 100 counts per 100
milliliters were observed after chlorination. The total coli-
form counts increased slightly in passage through the dechlor-
ination stage. This increase was fairly high on June 9 and
36
-------
U)
-J
TABLE III
Bacterial Removal in A Physical-Chemical System
by Chlorination - Dechlorination
Date
Raw A.M.
Raw P.M.
Coagulated A.M.
" " P.M.
Filtered A.M.
" P.M.
12 ' Carbon A.M.
P.M.
Chlorinated A.M.
P.M.
Effluent A.M.
" " P.M.
6/9/71
T.C.*
12 M***
14 M
1.6 M
3.3 M
1.05 M
3.1 M
1.3 M
0.93 M
100
100
2200
1700
6/10/71
T.C.
10 M
11.16 M
4.17 M
4.65 M
4 M
3 M
2 M
1.67 M
20
20
250
325
6/14/71
T.C. F.C.**
13.5 M
13.0 M
1.1 M
1.1 M
0.53 M
1.65 M
.28 M
.71 M
10
10
530
830
10.5 M
5.4 M
1.0 M
1.27 M
0.15 M
0.68 M
10
10
500
200
6/15/71
T.C. F.C.
14 M
22 M
4.6 M
4.2 M
4.2 M
3.9 M
3.9 M
2.9 M
0
0
25
25
12.5 M
16 M
3.0 M
0
0
50
50
Note: *T.C. - Total coliform per 100 ml of sample
**F.C. - Fecal coliform per 100 ml of sample
***M indicates million
-------
decreased during the remaining days until the total counts
in the plant effluent were below 25 per 100 milliliters. The
reason for the increase in total coliform counts from the
chlorination stage to the effluent was most probably due to
the fact that prior to June 9 the dechlorination carbon had
been exposed briefly to unchlorinated wastewater. On June 9
chlorination was initiated. Hence, a certain amount of
flushing and exposure to chlorinated wastewater, which for
all intents and purposes was sterile, was necessary before
the total coliform counts in the effluent receded.
The increase in chloride content of the wastewater due to the
chlorination^dechlorination process is shown in Table II. The
average chloride level in the Owosso raw wastewater over the
study period was 193 mg/1. This was increased to an average
of approximately 293 mg/1 after chlorination-dechlorination.
The results of all twenty-four hour surveys are tabulated in
Appendix A (Tables A-l through A-10). As noted by the data,
there was no breakthrough of free chlorine or trichloramine
on any of the samples taken. Periodically, the effluent from
the fourth or fifth carbon contactors would yield trace amounts
of mono- or dichloramines (0.1 to 0.4 mg/1). At times these
trace amounts were also noticed in the wastewater prior to
chlorination. The appearance of these trace amounts of chlora-
mines seems to be an anomaly of the test rather than a true
concentration. The data in Appendix A indicates, as antici-
pated, that the chlorination step causes a significant depression
of the pH, indicating that some type of pH adjustment or split
treatment arrangment may be necessary before the wastewater is
discharged.
Organic Removal
The results on biochemical oxygen demand (BOD) removal are
shown in Figures 15 and 16. This portion of the study was
divided into three distinct phases. Phase I of the study was
designed primarily to add support data to the existing pilot-
plant BOD data as reported by Schenk5 last summer at Owosso,
Michigan. Phase II of the study involved the application of
polymers prior to filtration (filter aid) in an attempt to
increase the solids removal efficiency of the deep-bed filter.
Phase III entailed a modification of the pilot facility
(addition of eight more feet of carbon) to reflect more
closely the envisioned full-scale carbon adsorption system.
Phase I (Figure 15) represents thirty-five days of operation
during which the pilot facility treated 235,269 gallons of
38
-------
tJ
« «o «o so IOO^MSO MO wo .
VOLUME THROUGHPUT - GALLONS X I03
-------
wastewater. Throughout phase I, the carbon adsorption system
had a total carbon contact depth of twenty feet resulting in
a twenty^five minute contact period. The first twelve feet of
carbon (fifteen minute contact time) were used before chlori-
nation while the last eight feet of carbon in columns 4 and 5
(ten minutes contact) were operated after the chlorination
section. A review of Figure 15 shows that during Phase I the
pilot facility produced an effluent BOD which averaged 7 mg/1.
On only seven days during this period did the daily average
effluent BOD exceed 7 mg/1. The majority of these high BOD
effluent values (greater than 7 mg/1) were observed after
passage of approximately 180,000 gallons of wastewater through
the system. At this through-put volume (180,000 gallons),
analysis of the BOD data indicated that the first carbon
column was at or near exhaustion. Operating at a reduced car-
bon contact time would explain the gradual rise in effluent
BOD after this point (180,000 gallons). Evaluation of these
data for Phase I yielded a carbon requirement of approximately
500 pounds per million gallons of wastewater treated (0.60 -
0.70 pounds of COD removed per pound of carbon). This substanti-
ates the findings of Schenk.5
The lime-phosphate floe developed in the coagulation phase
is a unique floe being light in substance and pin-point in
nature, which caused some difficulty in the deep-bed filtra-
tion stage. Although the deep-bed filter reduced the suspended
solids to between 20 and 25 mg/1, some operational difficul-
ties within the expanded-bed carbon system were experienced
even at these solids levels. The difficulties included among
other things: clogged underdrains, solids deposition at the
interface of the expanded carbon beds (these solids on top of
the carbon contactors were removed periodically), and periodic
wave-front movement of suspended solid material from carbon
column to carbon column.
The solids accumulation at the carbon-water interface in no
way interfered with the performance of the carbon unit, but
was of concern from an operational viewpoint. Hence, it was
deemed necessary to attempt to improve the deep-bed filter
performance by use of a polymer as a filter aid. Figure 15
shows the results of these Phase II studies on the BOD removal
through the system. The BOD removal efficiency of the carbon
system did not increase and, in fact, appeared to deteriorate,
while little or no improvement could be noted in the perform-
ance of the deep-bed filter (see Figure 19). In addition, the
effluent from the deep-bed filter tended to foam, indicating
some leakage of polymer through the filter.
Because of the problems encountered in Phase II, the polymer
feed system was shut down and Phase III initiated. In order to
provide a longer contact time, the carbon system was modified
40
-------
by the addition of two small diameter carbon columns (5-1/2
inch. I.D.) after the five large diameter carbon columns (12
inch I.D.). This resulted in a total carbon depth of twenty--
eight feet and yielded a contact time of approximately thirty-
five minutes. This mode of operation was more in line with
the actual carbon contact depth (prior to chlorination)
proposed for the full-scale Owosso system. The ammonia-nitrogen
removal study was terminated at this point because the small
carbon columns were not designed to operate as dechlorination
columns (no air relief valves).
The results on BOD removal during Phase III are shown in Figure
16. The data reported during this phase of the study represent
thirteen days of continuous operation. The average BOD of the
raw waste for this period was 140 mg/1/ the deep-bed filter
effluent yielded an average BOD of 32 mg/1, and the average
effluent BOD after thirty-five minutes carbon contact was
8 mg/1.
A summary of the chemical oxygen demand (COD) results for the
total test period is shown in Figures 17 and 18. In Phases I
and II (Figure 17), the average raw COD was 257 mg/1 and the
average effluent COD was 30 mg/1 (after twenty-five minutes of
carbon contact), resulting in an overall COD removal efficiency
of 88 per cent. In Phase III (Figure 18) the average COD of
the raw wastewater was 349 mg/1 and the average COD in the
effluent (after thirty-five minutes carbon contact) was 24 mg/1,
for a total "COD removal of 93 per cent.
Suspended Solids and Phosphate Removal
Suspended solids and phosphate removal observed during the
study are shown in Figures 19-20 and 21-22 respectively. The
average raw wastewater suspended solids during Phases I and
II (see Figure 19) was 134 mg/1. The average suspended solids
in the effluent was 14 mg/1. In Phase III (refer to Figure 20)
the average raw suspended solids was 186 mg/1 with a corres-
ponding effluent suspended solids level of 20 mg/1.
Phosphate removal data are shown in Figures 21 and 22 for
Phases I through III. Phosphate removal over the entire test
period averaged approximately 82 per cent.
Organic Nitrogen
The system's ability to remove organic nitrogen is shown in
Table IV. Organic nitrogen removals varied between 80 and 100
per cent and averaged 90 per cent during the observation period.
41
-------
FIG. 16 - DAILY BOD REMOVAL DURING TEST PERIOD
£UU
ion
mn
I/O
IAA
IK A
OU
I^O
IV)
ion
1 IA
IOO
_j on
J 90
o»
E 80
o
S70
TV
nn
50
An
3O
2O
in
0
1
\
\
\
*
\
\
r^.^
\
\
s
«
i -^
i
1
1
1
1
21
"^
P
A
/ \
'OAI
-A"
HAS!
\
\
A
\
DUV
*
i n
\
\
\
\
V
*^.
^^.
/
/
/
/
/
/
/
/
*
/
/
r- "
;V
\\
*
/ ^
^
AW
\
\
\
\
\
«
_^3(
w^^
^^^
H
^^d
.Ttn
\
,\
^ss,
,
1
1
1
1
1
sJ
rn
ED
x
A
/ '
/
/
/
/
f
/-
*.
\
\
\
\
i
\
\
\
\
\
^
^
' .
\
\
^«
"if
490 491 492 493 494 495 4M 497 498 499 500 501 9OZ 5O3 5O4 505 5O« 507
VOLUME THROUGHPUT GALLONS X I03
42
-------
360
340
FIG. 17 - DAILY COO REMOVAL DURING TEST PERIOD
20
60
420 460 500 540
VOLUME THROUGHPUT - GALLONS X 10
-------
500
FIG. 18 - DAILY COD REMOMM. DURING TEST PERIOD
O CO
49O
4«t 4*4 496 4*8 50O 802 504
VOLUME THROUGHPUT - GALLONS X I05
606
44
-------
it*
Ul
380
360
940
320
300
280
260
240
220
_KX>
180
"""160
§ 140
8 ,20
5 I0°
I80
P60
?40
20
A
FI8. 19- DAILY SUSPENDED SOLID* REMOVAL DURING TEST PERIOD
\
\
\
^
\
\
v
\
\
\
\
\
\
.
1
1
i
V
*
i
1
1
1
t-
/
1
/
/
/
/
*
0 20 40 80 80 100 H
1
'1
/
/
/
1
1
1
1
*-*
to M
1
1
|
1
|
1
1
|
1
1
1
1
I
|U
1
'i !
i
1 1
M
x
]
i
i
i
i
i
lv
V
t
1
1
~-J
^
\''
V
"S,
PHI
r*s
~-^.i
uli.^
V
\
\
V
r
1
/
r
^/
^
\
7"
O 'WO 180 200 220 240 MO MO 300 31
VOLUME THNOU8HPUT -
VAv
V
\x
y
^rP^
\-/'
~~*~*S
A
\
\
\
/
1
1
^
f
\
\
V
V^
A
M
i
1
1
1
|
1
I
i
*-«-(-
fHH
\
\
\
\
\
\
"
tO'Q
IMOI
t
(0 340 360 380 400 420 440 460 480 500
OALLONS X IO*
-------
FIG. 20-DAILY SUSPENDED SOLIDS REMOVAL DURING TEST PERIOD
too
IW)
ISO
iTn
IftA
MA
IAA
J
"Vjmo
gIBO
I2O
V)
S|,o
_l"°
"100
§*n
UJ an
0. "°
V)
5 7O
X
/
/
»
V
\
\
2
^
\'
V*
\
i
/
/
RBO
>
4
1
{
1
1
i
1
1
M
\,
*j
69
i
\
\
>
\
\
\
\
I
*^^
\
\
*x
490 491 492 493 494 496 496 497 498 499 8OO 601 60Z BOS 6O4 606 606 807
VOLUME THROUGHPUT GALLONS x 10*
46
-------
FIG. 21- DAILY PHOSPHATE REMOVAL DURING TEST PERIOD
45
PHASES
1
JVEFA6E
RCM3VAL
PHOSPHATE
82
40
35
rv
14
RAW
30
\
"~V
V
t*
V
V
20
^L
V
u I 5
I
^v;
U
20 CO 100 I4O ISO 220 2CO
VOLUME THROUGHPUT - GALLONS X KT
30O 34O 380 420 460 500 54O
-------
FIG. 22- DAILY PHOSPHATE REMOVAL DURING TEST PERIOD
PHASED!
46
38
\
. RkW
S
\
~ i§
j
r
*- 14
CAMIION
10
O
I
\
\
\
\
490 492 494 496 498 500 502 504 506 508
VOLUMt THROUGHPUT - GALLONS X I03
48
-------
TABLE IV
Organic Nitrogen Data
Cumulative
Throughput
(gallons)
63,272
97,789
111,106
181,683
189,441
201,923
Raw*
13.0
9.5
8.9
7.8
4.3
9.1
After
Filter*
6.0
1.4
-
-
3.9
7.0
After
12' Carbon*
(15 min, of
carbon contact)
0.6
-
2.2
0.56
1.12
0
After
20' Carbon*
(25 min . o f
carbon contact)
0.6
1.3
1.9
0.14
0.84
0
Percent
Removal
95
86
79
98
80
100
Average percent removal - 90%
*mg/l of Organic - N
49
-------
SECTION VIII
ACKNOWLEDGEMENT
The cooperation and assistance of the Owosso wastewater
treatment plant personnel, in particular Mr. Arnold VanPelt
and Mr. Steve Hanzlovic, is gratefully acknowledged. Their
assistance was of paramount importance in the successful
operation of this pilot study.
A special acknowledgement is extended to Mr. Neil Jackson,
City Manager, Mr. Ken Apsey, Director of Public Works and
Mr. Paul Wesch, Director of Public Utilities, all of the
City of Owosso, Michigan, whose far-sightedness, patience
and persistence made this project possible.
51
-------
SECTION IX
REFERENCES
1. "Standard Methods for the Examination of Water and
Wastewater", 13th Ed. American Public Health Associ-
ation, New York, New York. (1971)
2. Palin, A. T., "DPD Chlorine Residual Test" Water and
Sewage Works, 115, 331 (July, 1968).
3. Evans, F. L. , In-House Research Memorandum Environ-
mental Protection Agency, Cincinnati, Ohio.
4. Lawrence, A. W. , Howard, W. S., and Rubin, K. A.,
"Ammonia-Nitrogen Removal From Wastewater Effluents
by Chlorination", paper presented at the Fourth Mid-
Atlantic Industrial Waste Conference, University of
Delaware, November 19, 1970.
5. Schenk, J. E. , "Research Report - Physical-Chemical
Wastewater Treatment at Owosso, Michigan", September,
1970 (unpublished).
53
-------
SECTION X
APPENDICES
Appendix
A. Analytical Test Data During Twenty-Four Hour Survey Periods
Page No.
Table A-l - 3/3 to 3/4/71 56
Table A-2 - 4/30 to 5/1/71 57
Table A-3 - 5/13 to 5/14/71 59
Table A-4 - 5/14 to 5/15/71 60
Table A-5 - 5/15 to 5/16/71 61
Table A-6 - 5/23/71 62
Table A-7 - 5/27/71 63
Table A-8 - 6/9/71 64
Table A-9 - 6/14/71 65
Table A-10 - 6/15/71 66
55
-------
TABLE A-l
3/3/71 - 3/4/71
Sample
12' C
C12
20' C
12' C
C12
20' C
12' C
C12
20' C
4' C
ci2
201 C
12' C
Cl2
Time
9:00 pm
9:20 "
9:30 "
10:00 pm
10:20 "
10:30 "
11.00 pm
11:20 "
11:30 "
10:00 am
10:20 "
10:30 "
1:30 pm
1:50 "
Chloramines
NH- -N Free C12 Mono Di Tri
7.3
-
3.8
8.0
-
1.4
6.6
-
1.1
9.0
-
0.6
13.9
0
0.8
0
0
14.8
0
0
1.6
0
0
1.2
0
-
15.2
0 0.2 0
22.0 11.6 0
0 00
0 00
5.2 3.2 2.0
0.2 0 0
0 00
16.8 12.2 3.6
0 0.4 0
0 00
15.0 20.0 1.1
0.4 0 0
_ _
12.2 11.4 3.4
PH
9.0
6.9
8.6
9.0
7.1
8.4
9.0
6.2
7.6
8.8
6.7
7.0
8.4
6.9
All values in mg/1 except pH
56
-------
TABLE A-2
4/30/71
Sample
Raw
8' C
cl2
20' C
Raw
8' C
C12
20' C
Raw
8' C
C12
20' C
Raw
8' C
ci2
20' C
Raw
Raw
8' C
C12
20' C
Raw
8' C
C10
2
20' C
Raw
Time
4:00 pm
4:30 "
4:50 "
5:00 "
6:00 pm
6:00 "
6:20 "
6:30 "
8:00 pm
8:00 "
8:20 "
8:30 "
9:00 pm
9:30 "
9:50 "
10:00 "
10:00 pm
11:00 pm
11:00 "
11:20 "
11:30 "
12:00 mdnt
12:30 "
12:50 "
1:00 "
1:00 am
NH3-N Chlorides
23.7
27.0 156
11.75
12.0 280
22.5
10.0 148
1.0
1.8 260
11.2
22.5 140
11.8
11.55 250
10.0
11.0
0.5
0.6
10.0
12.0
11.0
2.3
-
11.1
12.0
1.4
1.5
11.0
Chloramines
Free Cl- Mono Di Tri
_ _ _ _
0.2 -
- - 2.0
0
- - -
_
_ _ _ _
0 - - 0
_
- - - -
76.0 0 0 0.4
0 0-0
_ _ _
- - -
76.0 000
0 0 38.0 0
_
_
-
76.0 000
0 0 37.0 0
_ _ _ _
_ _ _ _
_ - - -
0 -
_
pH
_
-
5.6
5.6
7.0
9.2
5.5
6.2
7.1
9.2
5.1
4.2
7.1
9.1
5.2
4.3
7.0
6.8
9.1
6.4
4.1
7.1
9.1
6.0
4.2
7.2
57
-------
TABLE A-2 (continued)
Sample
Raw
8' C
ci2
20' C
Raw
8' C
ci2
20' C
Raw
Raw
8' C
ci2
20' C
Raw
81 C
C12
20' C
Raw
Raw
81 C
C12
20' C
Raw
8' C
C12
20' C
Time
2:00 am
2:00 "
2:20 "
2:30 "
3:00 am
3:30 "
3:50 "
4:00 "
4:00 am
5:00 am
5:00 "
5:20 "
5:30 "
6:00 am
6:30 "
6:50 "
7:00 "
7:00 am
8:00 am
8:00 "
8:20 "
8:30 "
9:30 am
9:35 "
9:55 "
10:05 "
NH3-N Chlorides
11.5
13.0
2.1
2.2
10.0
10.5
1.5
1.4
9.0
9.5
9.5
1.0
1.0
8.0
8.0
0.95
0.9
-
6.5
7.5
0.98
0.95
8.0
6.0
1.0
1.0
Chloramines*
Free C12 Mono Di Tri pH
7.2
- - - 9.2
6.2
0 - 4.3
- - - 7.2
- - - 9.1
- - - 6.0
0 - 4.3
- - - 6.7
- - - 6.8
- - - 8.7
- - - 5.3
0 - 4.3
- - - 6.8
- - - 8.7
- - - 5.4
0 - 4.3
- - - 6.6
- - - 6.8
- - - 8.6
- - - 5.4
0 - - - 4.3
6.7
- - - 8.6
5.4
0 - 4.4
All values in mg/1 except pH
*Problem encountered in analyzing for chloramines due to contamin-
ation of chemicals - initial values invalid and chloramine
analyses terminated.
58
-------
TABLE A-3
5/13/71 - 5/14/71
Sample
81 C
C12
20' C
8' C
c^2
20' C
8' C
c^-2
20' C
8' C
C12
20' C
8' C
C12
20' C
8' C
ci2
20' C
8' C
20' C
8' C
20' C
8' C
20' C
81 C
25' C
8' C
ci2
20' C
8' C
ci2
20' C
Time
1:00
1:20
1:30
3:30
4:00
4:10
5:00
5:20
5:30
7:00
7:20
7:30
9:10
9:30
9:40
10:30
10:50
11:00
12:00
12:00
2:00
2:00
4:00
4:00
6:00
6:00
8:00
8:20
8:30
10:00
10:20
10:30
NH3-N
pm 15.4
-
1.7
pm 17.2
-
2.9
pm 16.8
-
0.84
pm 15.7
-
1.2
pm 14.1
-
1.1
pm 14 . 3
-
1.1
md 13.8
0.8
am 12.4
0.5
am 12.8
0.28
am 12.6
0.0
am 12.3
-
0.2
am 11.9
-
0.0
Chlorides
_
-
-
_
-
-
180
-
320
190
-
325
200
-
330
195
-
320
_
-
-
-
-
-
-
-
220
-
355
215
-
350
Chloramines
Free
_
1.6
0
1.2
0
_
0.4
0
_
1.6
0
_
0.8
0
-
1.6
0
-
-
-
-
-
-
-
-
0
2.0
0
-
11.6
0
C12 Mono
_
4.4
0
_
12.0
0
_
6.0
0
0
2.4
0
-
7.2
0.3
-
5.6
0.1
-
-
-
-
-
-
-
-
0.1
4.0
0
-
1.6
0.2
Di
8.0
0.2
_
21.6
0.2
_
21.6
0.2
0.3
22.4
0.3
22.8
0.3
-
16.4
0.3
-
-
-
-
-
-
-
-
0.2
16.0
0.2
-
3.6
0.2
Tri
_
24.8
0
_
4.8
0
_
14.4
0
0
0
0
_
1.6
0
-
7.2
0
-
-
-
-
-
-
-
0
20
0
-
20.8
0.3
PH
9.2
5.0
5.2
9.2
5.3
3.8
8.9
5.4
4.3
9.2
4.8
4.3
9.1
4.9
4.1
9.0
5.0
3.9
8.6
4.0
8.1
3.8
7.9
4.0
8.6
4.8
4.0
7.9
5.7
4.2
All values in mg/1 except pH
59
-------
TABLE A-4
5/14/71 - 5/15/71
Chloramines
Sample
8' C
C12
20' C
8' C
C12
20* C
8' C
C12
20' C
81 C
C12
20' C
81 C
C12
20' C
8' C
20' C
8' C
20' C
8' C
20' C
8' C
20' C
8' C
C12
20' C
8' C
C12
20' C
8' C
C12
20' C
Time
12:30
12:50
1:00
2:45
3:05
3:15
5:10
5:30
5:40
7:00
7:20
7:30
9:15
9:35
9:45
NH3-N
pm
ii
"
pm
"
11
pm
"
pm
pm
11
pm
"
14.
-
0.
16.
-
0.
17.
-
1.
16.
-
1.
16.
-
0.
12:00mdntl4.
12:00
2:00
2:00
4:00
4:00
6:00
6:00
8:00
8:20
8:20
10:00
10:20
10:30
"
am
"
am
"
am
11
am
"
11
am
"
"
0.
14.
0.
12.
0.
12.
0.
12.
-
0.
11.
-
0.
12:00noonl4.
12:20
12:30
-
0.
8
14
8
7
6
9
3
0
0
5
0
0
0
5
7
4
0
1
0
1
9
0
0
0
Chlorides Free Cl
300
-
450
265
-
415
200
-
350
175
-
325
180
-
330
-
-
-
-
-
-
-
-
185
-
345
180
-
335
265
-
425
0
1.6
0
-
0.8
0
-
10.0
0
-
1.6
0
-
2.0
0
-
-
-
-
-
-
-
-
0
14.0
0
0
18.8
0
-
6.4
0
2 Mono
0.2
2.0
0
-
6.8
0.1
-
0.8
0
-
3.2
0.1
-
3.2
0
-
-
-
-
-
-
-
0
0
0
0.1
0.4
0
-
2.0
0
Di
0
28
0
-
31
0
-
20
34
0
-
19
24
0
-
24
28
0
-
-
-
-
-
-
-
-
0
4
0
0
12
0
3
0
.3
.4
.2
.2
.4
.4
.4
.5
.2
.8
.2
.4
.8
.3
.2
.0
.3
.2
.2
.1
Tri
0
1.6
0
-
4.8
0
-
0
0
-
1.4
0
-
0
0
-
-
-
-
-
0
1.6
0
0
0.8
0
_
6.4
0
pH
8.6
5.7
4.8
8.8
5.4
4.8
9.0
5.0
4.3
9.1
4.8
4.5
9.4
5.0
4.8
9.0
4.7
9.0
3.9
9.1
3.8
9.0
3.7
9.0
4.0
3.6
9.0
4.8
3.5
9.0
4.3
3.4
All values in mg/1 except pH
60
-------
TABLE A-5
5/15/71 - 5/16/71
Sample
8' C
C12
20' C
8' C
C12
20' C
8' C
ci2
20' C
8' C
c^2
20' C
8' C
C12
20' C
8' C
20' C
8' C
20' C
8' C
20' C
8' C
20' C
8' C
ci2
20' C
8' C
C12
20' C
8' C
C12
20' C
Time
2
2
2
4
4
4
6
6
6
8
8
8
10
10
10
12
12
2
2
4
4
6
6
8
8
8
10
10
10
12
12
12
:00
:20
:30
:00
:20
:30
:00
:20
:30
:00
:20
:30
:00
:20
:30
:00
:00
:00
:00
:00
:00
:00
:00
:00
:20
:30
:00
:20
:30
NH
pm 17
" -
5
pm 18
"
8
pm 17
" -
6
pm 15
11 -
5
pm 14
"
4
mdnt!3
2
am 14
2
am 13
2
am 13
2
am 12
"
2
am 13
II _
2
:00noon 14
:20
:30
-
2
3-
.2
.5
.3
.2
.2
.5
.5
.1
.0
.1
.6
.1
.3
.8
.7
.2
.0
.2
.6
.0
.0
.5
.0
.7
Chlorides
_
-
-
185
-
280
180
-
280
160
-
265
185
-
275
_
-
_
-
_
-
_
-
190
-
290
_
-
-
_
-
~
Chloramines
Free C12 Mono
_
1.6
0
0
0.8
0
-
0.4
0
0
0.4
0
-
0.4
0
_
_
-
_
-
_
_
0.2
0
0
0.2
0
-
0.2
0
_
20.4
0
0
22.0
0
_
22.4
0
0.1
22.0
0
_
20.0
0
_
-
_
-
_
-
_
_
17.2
0
0
14.4
0
-
16.0
0
Dl
_ .
19
0
0
17
0
_
16
0
0
16
0
-
12
0
-
_
_
_
-
21
0
0
12
0
-
14
0
.6
.1
.2
.2
.2
.8
.1
.1
.4
.0
.1
.6
.2
.1
.8
.1
.2
.1
Tri
0
0
0
3.2
0
0
0
0
0
0
-
0
0
-
-
-
-
~
-
3.2
0
0
2.4
0
-
3.0
0
pH
9.1
6.1
3.5
9.1
6.3
3.6
9.0
6.3
3.9
9.2
6.3
4.3
9.1
6.1
4.2
9.1
5.3
9.1
5.2
9.1
5.3
9.1
5.3
9.1
5.8
5.2
9.0
5.9
5.3
9.1
5.6
5.4
All values in mg/1 except pH
61
-------
TABLE A-6
5/23/71
Chloramines
Sample
8' C
C12
16' C
201 C
8' C
ci2
16' C
20' C
8' C
C12
16' C
20' C
8' C
C12
16' C
20' C
Time
7:30 am
7:50 "
7:55 "
8:00 "
9:30 am
9:50 "
9:55 "
10:00 "
11:30 am
11:50 "
11:55 "
12:00 "
1:30 pm
1:50 "
1:55 "
2:00 "
NH3
11.1
-
-
0
11.7
-
-
0.2
12.7
-
-
0.8
13.5
-
-
1.2
Free C12
^
4
0
0
_
3.5
0
0
_
3.0
0
0
-
3.4
0
0
Mono
7.2
0
0
8.0
0
0
_
8.1
0
0.1
-
8.2
0
0
Di
_
16.8
0.3
0.2
17.0
0.3
0.1
_
17.2
0.2
0
-
16.8
0.3
0.2
Tri pH
3.0
0
0
2.0
0
0
_
2.4
0
0
2.8
0
0
All values in mg/1 except pH
62
-------
TABLE A- 7
5/27/71
Chloramines
Sample
8'
Cl
16
20
8'
Cl
16
20
8'
Cl
16
20
Cl
16
20
8'
Cl
16
20
C
2
1 C
1 C
C
2
1 C
1 C
C
2
1 C
1 C
2
1 C
1 C
C
2
1 C
1 C
9
9
9
9
11
11
11
11
1
1
1
1
2
2
2
3
3
3
3
Time
:00 am
:20 "
:20 "
:30 "
:00 am
:20 "
:20 "
:30 "
:00 pm
:20 "
:20 "
:30 "
:00 pm
:00 "
:10 "
:00 pm
:20 "
:20 "
:30 "
NH^ Free C12 Mono Di
11.6
-
-
0.7
14.4
-
-
0
16.8
-
1.4
-
-
-
17.0
-
-
2.6
mm
4.0
0
0
0
9.6
0.2
0
0
2.0
0.2
0
0.4
0
0
0
2.4
0
0
0
0
2
1
5
0
11
0
11
0
^
.4
.2
0
0
.8
.3
0
0
.6
.1
0
.2
.1
0
0
.6
.1
0
^
9
0
0
0
8
1
0
0
17
1
0
17
0
0
0
20
0
0
.2
.8
.2
.1
.0
.4
.1
.2
.6
.0
.2
.2
.8
.1
.1
.4
.8
.2
Tri
M
0.8
0
0
0
0
0
0
0
0.2
0
0
0.8
0
0
0
0
0
0
pH
8.8
4.8
4.4
4.4
8.8
4.5
4.3
4.2
8.9
5.5
4.4
4.4
6.0
4.4
4.4
6.0
4.2
4.2
All values in mg/1 except pH
63
-------
TABLE A- 8
6/9/71
Chloramines
Sample
8' C
Cl,
16f C
20' C
81 C
ci2
16' C
20' C
8' C
C12
16' C
20' C
81 C
C12
16' C
20' C
81 C
C12
16' C
20' C
8' C
C12
16' C
20' C
8' C
C3-2
16' C
20' C
8' C
C12
16' C
20' C
Time
8:00 am
8:20 »
8:20 "
8:30 "
10:00 am
10:20 "
10:20 "
10:30 "
12:00noon
12:20 pm
12:20 "
12:30 "
2:00 pm
2:20 "
2:20 "
2:30 "
4:00 pm
4:20 "
4:20 "
4:30 "
6:00 pm
6:20 "
6:20 "
6:30 "
8:00 pm
8:20 "
8:20 "
8:30 "
10:00 pm
10:20 "
10:20 "
10:30 "
NH3
12.8
_
3.0
15.5
-
-
3.0
17.4
-
-
5.0
21.6
-
-
8.4
22.7
-
-
9.0
20.5
-
-
5.6
19.4
-
-
5.0
19.0
-
5.1
Chlorides Free C12 Mono
200
_
340
510
-
-
655
365
-
-
510
260
-
405
220
-
'-
370
-
-
200
-
-
345
-
1.6
0
0
0
0.8
0
0
_
0.8
0
0
-
1.2
0
0
-
0.8
0
0
-
0.6
0
0
-
0.8
0
0
-
0.6
0
0
10.4
0
0
0
7.2
0
0
_
14.0
0
0
0.1
14.0
0
0
-
20.8
0
0
-
20.0
0
0
16.8
0
0
-
16.0
0
0
Di
20.0
0.4
0
0
18.0
0.3
0
_
24.0
0.3
0
0.1
28.0
0.4
0
30
0.2
0
-
23.2
0.3
0
24.4
0.2
0
22.4
0.3
0
Tri
1.6
0
0
0
1.6
0
0
_
0
0
0
0
0
0
0
-
0
0
0
-
0
0
0
_
0
0
0
0
0
0
pH
9.0
4.8
5.0
5.2
9.0
4.7
5.0
5.1
8.9
5.2
5.1
5.2
9.0
5.3
5.3
5.3
9.1
5.3
5.2
5.2
9.0
5.7
5.4
5.4
9.0
5.7
5.3
5.3
9.0
5.7
5.4
5.4
All values in mg/1 except pH
64
-------
TABLE A-9
6/14/71
Chloramines
Sample
8' C
Cl,
16 C
20'C
8' C
C12
16' C
20' C
8' C
0-2
16' C
20' C
8' C
C12
16' C
20' C
81 C
C12
16' C
20' C
8' C
C12
16' C
20' C
Time
7:30 am
7:30 "
7:40 "
7:40 "
9:00 am
9:20 "
9:20 "
9:30 "
11:00 am
11:20 "
11:20 "
11:30 "
1:00 pm
1:20 "
1:20 "
1:30 "
3:00 pm
3:20 "
3:20 "
3:30 "
5:00 pm
5:20 "
5:20 "
5:30 "
NH3
12.7
-
-
0.8
11.1
-
-
0.4
12.7
-
-
0.3
17.4
-
-
1.25
26.3
-
_
4.6
19.7
-
-
4.6
Chlorides
180
-
-
370
200
-
-
400
220
-
-
415
220
-
-
410
210
-
-
395
215
-
-
405
Free
0
4.8
0
0
_
6.8
0
0
0
6.0
0
0
_
0.8
0
0
0
0.2
0
0
_
0.4
0
0
C12 Mono
0.1
3.2
0.1
0
-
2.0
0.2
0
0
1.2
0.1
0
-
8.4
0
0
0.2
16.4
0
0
-
18.2
0
0
Di
0.3
20.8
0.6
0.4
-
7.2
0.3
0.2
0.1
6.0
0.4
0.3
-
34.4
0.7
0.2
0.2
28.2
0.6
0.1
-
30.4
0.5
0.3
Tri
0
4.0
0
0
-
8.0
0
0
0
10.2
0
0
-
0
0
0
0
0
0
0
-
0
0
0
pH
9.0
4.2
3.7
3.6
9.1
4.4
3.7
3.7
9.0
4.8
3.7
3.6
8.9
5.1
3.8
3.6
9.0
5.6
3.8
3.7
9.0
5.8
3.9
3.8
All values in mg/1 except pH
65
-------
TABLE A-10
6/15/71
Chloramines
Sample
8' C
Cl2
16' C
20' C
8' C
Cl2
16' C
20' C
8' C
ci2
16' C
20' C
8' C
C12
16* C
20' C
8' C
Cl2
16' C
201 C
Time
7:00 am
7:20 "
7:20 "
7:30 "
9:00 am
9:20 "
9:20 "
9:30 "
11:00 am
11:20 "
11:20 "
11:30 "
1:00 pm
1:20 "
1:20 "
1:30 "
2:30 pm
2:50 "
2:50 "
3:00 "
NH3
14
-
-
0.28
13.3
-
-
0
15.8
-
-
0
17.6
_
-
4.5
17.2
-
-
7.6
Free Cl2
0
2.4
0
0
_
4.8
0
0
0
6.4
0
0
-
2.0
0
0
-
2.4
0
0
Mono
0
0.8
0
0
_
1.6
0
0
0
2.8
0.1
0
-
8.4
0.2
0
-
10.0
0.1
0
Di
0.3
11.8
0.4
0.3
_
7.6
0.5
0.3
0.1
18.2
0.5
0.2
-
42.4
0.6
0.5
-
38.2
0.7
0.3
Tri
0
2.4
0
0
_
2.4
0
0
0
2.0
0
0
-
0
0
0
-
0
0
0
PH
8.6
5.8
5.2
5.2
8.5
6.2
5.7
5.6
6.3
5.6
5.6
9.2
6.1
5.7
5.7
9.2
6.2
5.8
5.8
All values in mg/1 except pH
U. S. GOVERNMENT PRINTING OFFICE : 1972514-150/110
66
-------
SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
I. Rep-TtNo
'i. Accession No.
w
4. Title
AMMONIA REMOVAL IN A PHYSICAL-CHEMICAL
WASTEWATER TREATMENT PROCESS
7. Author(s)
Barnes, R. A., Atkins, P. A., and Scherger, D. A.
9. Organization
Ayres, Lewis, Norris & May, Inc., and Environmental
Control Technology Corp., Ann Arbor, Michigan
12. Sponsoring Organization
IS Supplementary Yo:es
Environmental Protection Agency report
number EPA-R2-72-123, November 1972.
5. R
6.
B. Performing Organization
Report No.
10. Project No.
EPA.ORM 17010 HAM 3/72
.'( Contract/Grant No
EPA..OBM 68-01-0049
13. Type el Report and
Period Covered
16. Ab^ract
The pilot scale study at Owosso, Michigan, was a physical-chemical waste-
water treatment system consisting of chemical coagulation (lime to pH 8.8 to
9.4) sedimentation, deep bed'filtration, carbon adsorption, chlorination to
oxidize ammonia, and carbon dechlorination to remove free chlorine and chloramines.
Ammonia-nitrogen was removed to any desired level by the chlorination-
dechlorination system. Complete removal from Owosso wastewater would require a
chlorine to ammonia feed ratio of 9 to 1. The dechlorination carbon removed free
chlorine and also the chloramines formed at less-than-breakpoint operation.
There is an initial ammonia-nitrogen breakthrough when using fresh dechlori-
nation carbon which is attributed to acclimation rather than continuous leakage.
After the period of acclimation, the dechlorination carbon removed free chlorine
and all forms of chloramine without evidence of exhaustion. An hypothesis de-
scribing chloramine removal is presented. (Evans-EPA)
i7a. Descriptors *Chlorination (Breakpoint), *Ammonla, *Chlorine Compounds, ^Activated
Carbon, Sewage Treatment, Oxidation
176. identifiers Dechlorination (Activated Carbon) , Chloramine Removal (Carbon),
*
Physical-Chemical Treatment, Dechlorination Theory
17c. COWRR Field & Group
IS. A vail ability
19. S' -urityfass.
(Report)
20. Security Class.
21. Ko, of
Pages
22. Price
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S DEPARTMENT OF THE INTERIOR
WASHINGTON, D. C. 2O24O
Abstractor Francis L. Evans III | Institution Environmental Protection Agency. NERC.AWTRL
Wfil5IC 102 (REV JUNE 1971)
------- |