EPA-660/2-75-006
May 1975
Environmental Protection Technology Series
Plant Scale Studies of the Magnesium
Carbonate Water Treatment Process
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Corvallis, Oregon 97330
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development,
U.S. 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
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY STUDIES 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 provides the
new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
EPA REVIEW NOTICE
This report has been reviewed by the Office of Research and
Development, EPA, and approved for publication. Approval does
not signify that the contents necessarily reflect the views and
policies of the Environmental Protection Agency, nor does mention
of trade names or commercial products constitute endorsement or
recommendation for use.
Document is available to the public through the National Technical
InfCQQiQtion Service, Springfield, Virginia 22151.
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EPA-660/2-75-006
May 1975
PLANT SCALE STUDIES OF THE MAGNESIUM
CARBONATE WATER TREATMENT PROCESS
By
A. P. Black
&
C. G. Thompson
Project #12120 HMZ
Program Element 1BB036
ROAP/Task No. 21BAE/18
Project Officer
Edmond P. Lomasney
Research & Development Program Director
U. S. Environmental Protection Agency
Atlanta, Georgia
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CORVALLIS, OREGON 97330
-------
ABSTRACT
The Magnesium Carbonate Process of water treatment
has replaced alum in a portion of two (2) water plants in
full scale studies conducted over the past two and one-half
years. This new water treatment technology was compared to
the presently used alum process in parallel treatment using
identical units in Montgomery, Alabama and Melbourne, Florida.
The results of these studies indicate that this
new process offers a number of significant advantages over the
alum process. The primary advantage is that the existing prob-
lem of sludge disposal in Melbourne's case is completely elim-
inated and at Montgomery is greatly reduced. All water is re-
cycled within the process along with the three (3) basic
water treatment chemicals - lime, magnesium bicarbonate, and
carbon dioxide. Other advantages found were increased floe
settling rates, simplicity of operation and control, reduced
costs when sludge treatment and disposal costs are considered,
and more complete disinfection. In Melbourne's case, con-
siderable energy would be conserved by on-site lime recovery.
In addition to the two full scale studies a number
of special studies were conducted in Montgomery using a 50 gpm
pilot plant. These studies showed almost complete removal of
added cadmium by the highly adsorptive Mg(OH)- floes and that
it was not released during sludge carbonation and magnesium
recycling.
This report was submitted in fulfillment of Project
Number 12120 HMZ, by the Montgomery Water and Sanitary Sewer
Board, under the partial sponsorship of the Environmental
Protection Agency. Work was completed as of June 1973.
ii
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CONTENTS
SECTIONS Page
I Conclusions 1
II Recommendations 3
III Introduction 7
IV Description of Project Phases 17
V Results and Discussions 33
VI References 93
VII Appendices 95
iii
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FIGURES
No. Page
1. Magnesium Recycle Magnesium Process
Flow Diagram 10
2. Lime Recovery Magnesium Process Flow
Diagram 12
3. Lime and Magnesium Recovery Magnesium
Process Flow Diagram 14
4. Magnesium Demonstration Pilot Plant
Layout 18
5. Details of Rapid Mix Units and Chemical
Additions - Montgomery, Alabama 22
6. Flocculation pH Control System -
Montgomery 23
7. Montgomery WTP Solids Handling Facilities 25
8. Solubility of Magnesium as a Function of
C02 Partial Pressure 26
9. Sludge Carbonation pH Control System -
Montgomery 28
10. Layout of Melbourne Water Plant Converted
to Include the Magnesium Process 30
11. Comparison of Theoretical Solubility of
Mg{OH)2 with Observed Jar Test and Pilot
Plant Values 35
12. Effect of pH on Coliform Survival -
Laboratory Studies 40
13. Thickening Characteristics of Alum and
Magnesium Studies 42
14. % Sludge Solids Versus Vacuum Filter
Rate - Montgomery 43
15. Fruendlich Isotherm for Carbon Ad-
sorption of Organic Color with Activated
Carbon 4 6
xv
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No.
Page
16. Process Control Points and Sampling
Locations - Montgomery 53
17. Relationship Between Raw and Settled
Turbidity as a Function of Time and
Magnesium Dosage - Montgomery 56
18. Montgomery Stabilized Water - Total
and Magnesium Hardness 57
19. Make-up Magnesium Cost as a Function of
Coagulation pH - Montgomery 59
20. Lime and CO2 as a Function of Coagulation
pH - Montgomery 60
21. Lime, CO2, and Magnesium Total Cost as
a Function of Coagulation pH -
Montgomery 61
22. Lime and Magnesium Costs as a Function of
Coagulation pH - Montgomery 63
23. Corrosion Rates for Alum and Magnesium
Treated Water - Montgomery 68
24. Raw Water Color and Treated Water Color
as a Function of Time and Magnesium
Dosage 74
25. Magnesium Sinks and Sources as a Function
of Time - Melbourne 76
26. Color/Magnesium Ratio as a Function of
Time - Melbourne 78
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TABLES
No. Page
1. Cities Treating Soft Surface Waters 11
2. Cities Treating Moderately Hard, Turbid
Surface Waters 13
3. Cities Treating Hard Turbid Surface
Water 15
4. Typical Range in Raw Water Characteristics
Tallapoosa River, Montgomery, Alabama 20
5. Typical Range in Raw Water Characteristics
Lake Washington, Melbourne, Florida 29
6. Typical Pilot Plant Results 36
7. Pilot Plant Results During Rapid Water
Quality Deterioration 37
8. Summary of Coliform Survival Laboratory
Studies 39
9. Carbon Adsorption of Released Organic
Carbon 4 5
10. Carbon Adsorption of Released Organic
Color 45
11. Use of Chlorine to Reduce Organic Color 47
12. Effectiveness of Alum in Removing Cadmium 47
13. Effectiveness of Lime in Removing Cadmium
from Water in Jar Tests 48
14. Effectiveness of Magnesium Hydroxide in
Removing Cadmium from Water in Jar Tests 48
15. Pilot Plant Results - Cadmium Study 50
16. Control Systems and Sampling Location 55
17. Raw Water Analyses and Alum Dosages,
Montgomery, Alabama 6 3
18. Vacuum Filter Data, Montgomery, Alabama 66
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No. Page
19. Comparison of the Magnesium and Alum
Treatment Processes at Montgomery 69
20. Estimation of Capital Cost for Montgomery's
Plant Conversion 72
21. Chlorine Demand Test 79
22. Leaf Filter Test Results - Melbourne 80
23. Full Scale Vacuum Filter Results -
Melbourne 80
24. Melbourne Sludge Thickening Study 81
25. Design Table Summary 86
VI1
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ACKNOWLEDGEMENTS
Acknowledgement is extended to the following per-
sonnel of the Montgomery Water and Sanitary Sewer Board for
their assistance, advice and counsel which contributed in
carrying out this study:
Mr. Nat P. Wiley, Manager
Mr. Joe L. Coleman, Chairman
Mr. M. L. French, Chief of Maintenance
In the Melbourne phase of the project, special re-
cognition is extended to Smith and Gillespie Engineers, Inc.,
Melbourne's consulting engineers, for their foresightedness
in seeking a new and novel approach to an old problem. The
planning and assistance of Messrs. John H. Grantham and John
M. Colyer were responsible for the inception and direction of
this phase of the project.
Acknowledgement is also extended to the following
personnel of the City of Melbourne:
Mr. Richard V. Donahue, Mayor
Mr. John C. Watkins, City Manager
Mr. Cal Yeary, Plant Superintendent
Special acknowledgement is extended to the water
plant operators at both Melbourne and Montgomery whose effort
and cooperation made this project possible.
Acknowledgement is extended to the American Water
Works Research Foundation for their financial assistance to
this project.
Mr. Edmond P. Lomasney, Project Officer is extended
acknowledgements for his guidance and counsel throughout this
project.
VIXI
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SECTION I
CONCLUSIONS
The use of magnesium carbonate as a recycled coagulant
has been found to equal or exceed the results obtained
by the use of alum in every aspect of water treatment
including: water quality produced, operational charac-
teristics, economy, and adaptability over a wide range
of raw water qualities.
The Montgomery raw water is too soft to consider lime
recovery; however, in Melbourne's case, where lime re-
covery is economically attractive, no solid or liquid
discharge will result. The coagulated color will be
converted to carbon dioxide on calcination and the
three primary water treatment chemicals (magnesium,
carbon dioxide and lime) recycled within the process.
In Montgomery, the easily dewatered filter cake will
be available for use as a soil pH stabilizer. Con-
siderable quantities of limestone are presently pur-
chased in Alabama for this purpose each year.
The increased floe density produced by the magnesium
process will allow higher clarifier loading rates.
In Melbourne the present loading rates were doubled
without a deterioration in the quality of the clari-
fier effluent.
Reduced treatment costs were found when sludge dewa-
tering and ultimate disposal costs were considered.
In Melbourne this cost savings would be in excess of
ง100,000 per year for a water production of 10 MGD.
In evaluating the results of these studies, it should
be kept in mind that from the standpoint of treatment
costs, they represent the most unfavorable conditions
-------
for this process. The greatest benefits from the new
technology will be obtained by major cities treating
hard waters containing sufficient lime to recalcine.
6. The chemical quality of the treated water was improved
in both the Melbourne and Montgomery studies. In Mont-
gomery the increase in finished water alkalinity using
the Magnesium Process reduced the corrosion rate to
one-half the value found for the extremely soft alum
treated water. In Melbourne a considerably softer
water would be produced during the winter months.
7. Plant personnel demonstrated their proficiency in the
operation of the process under difficult conditions.
The nature of the process is such that pH control at
three (3) critical points is the primary method of
insuring adequate treatment, producing excellent quality
over a wide range of influent quality. The process was
found to be easily automated and controlled.
8. The full scale use of this new process is compatible
with most existing water treatment plants requiring a
minimum of land area and capital cost. The conversion
of most existing alum treatment plants to this new tech-
nology involves few internal process changes and only
minor piping changes to add the necessary recovery and
recycling units.
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SECTION II
RECOMMENDATIONS
E.P.A. Project 12120 HMZ recently completed in
Montgomery and Melbourne has shown that this process is
practical for soft, turbid waters and moderately hard waters
high in organic color. Magnesium recovery and recycle has
been shown to be practical and economically feasible. This
project has provided design criteria which are applicable
to many water plants utilizing the types of raw water in-
vestigated in this project. The need for extensive pilot
studies by each of these type plants is eliminated.
Hard turbid water presents the most serious problems
in sludge disposal due primarily to the large quantity of
sludge to be treated. While these sludges generally dewater
more readily than soft water sludges, high disposal costs
can result dre to the quantity to be hauled to a suitable
landfill. Lime recovery from the precipitated calcium car-
bonate has been to date considered unfeasible due to the high
silt content; however, the use of flotation separation of the
calcium carbonate now makes lime recovery possible. All of
the unit processes have been demonstrated in the laboratory;
however, pilot or full scale studies have been conducted in
only limited areas. In the application of new technology,
considerable caution must be exercised. In the case of this
process the use of pilot and/or demonstration plants are
required' before considering such a drastic process change to
a full scale plant operation.
Work completed at Dayton, Ohio is directly appli-
cable to only a very few cities treating clear ground water.
The magnesium carbonate production studies carried out to date
have been conducted on a batch basis with little attention
given to obtaining design information. The influence of raw
-------
water impurities on the magnesium compounds has not been eval-
uated nor the various means of removing these impurities prior
to magnesium carbonate precipitation.
At the present time, there have been three E.P.A.
funded projects related to the overall magnesium process. The
first project was a laboratory study conducted at Gainesville,
Florida, Project 11060 ESW, and concluded in May of 1971. The
second was the Demonstration Project 12120 HMZ reported on here,
The initial objectives of this project were concerned with the
treatment of a very soft, low magnesium water at Montgomery,
Alabama with no consideration given for magnesium production.
The extension of this project in Melbourne, Florida, studied
the application of the process for treatment of a much harder,
highly colored, low turbidity water. The third project, in
Gainesville, Florida, 12130 HRA, was for the treatment of mun-
icipal and industrial wastes. This latter project has been
completed, and a final report submitted.
A comprehensive research project, 802800, has also
been initiated to study the application of the lime and mag-
nesium recovery aspects of this process on a hard, high mag-
nesium, turbid surface water at Johnson County, Kansas. The
specific objectives of the proposed research are:
1. Determine the technical feasibility of separating
calcium carbonate from the clay turbidity by froth
flotation. This must be accomplished during wide
variations in raw water quality. The seasonal ef-
fects on both the sludge character and the flotation
process should be evaluated.
2. A study of the production of magnesium compounds
from a relatively poor quality raw water in con-
tinuous flow, pilot scale studies.
3. Development of design information for all required
unit operations where recovery is found to be tech-
nically feasible.
4. Conduction of a economic analysis for full scale
application of lime and magnesium recovery. A
-------
projection as to the cost effectiveness of these
recovery processes as a function of plant size and
raw water quality will be made.
The studies in Melbourne have shown the process to
be applicable to color removal at moderately high levels. A
sample of the total effluent from an unbleached southern kraft
pulp mill was collected for laboratory jar testing. This eff-
luent had received only settling as treatment and had the fol-
lowing characteristics:
pH 8.3
Total Alkalinity 328 mg/1
(as CaCO3)
Color (Pt.-Co. Units) 530 mg/1
A number of jar tests were run using different dos-
ages of magnesium carbonate, coagulating at a constant pH of
11.3. A summary of these tests is as follows:
Chemical Dosages
Magnesium Dosage* (mg/1 as CaCC^} 350
Lime Dosage mg/1 as Ca(OH)2 430
Treated Stabilized Waste Characteristics
pH 8.5
Alkalinity as CaCO3 213
^Color (Pt.-Co. Units) 53
% Color Removal 90
For comparative purposes a brief study was made of
the use of alum for the coagulation of the color present.
Three hundred (300) mg/1 of alum produced a treated effluent
with a COD of 205 mg/1 and a color of 93 mg/1. This indicates
a COD removal of 64% and a color removal of 83%. At an alum
cost of 2.1C per pound a chemical cost of greater than $52 per
million gallons could be expected. Based on these limited
*Magnesium dosages are expressed in terms of calcium carbonate
equivalents for simplicity. The actual magnesium form used
may be magnesium sulfate, magnesium carbonate, magnesium bi-
carbonate , etc.
-------
studies, the chemical cost for the magnesium process would be
approximately $20.00 per million gallons.
Presently, lime treatment of these wastes is con-
sidered most often when color removal is required in conjunc-
tion with conventional treatment. The use of the magnesium
process would appear to offer the following advantages over
the Massive or Stoichiometric Lime Processes:
1. The sludge produced should be considerably easier
to dewater due to the higher calcium carbonate con-
tent.
2. Due to magnesium recycle, a lower coagulation pH
is possible generally in the range of 11.2 to 11.4.
3. Chemical costs should be considerably less due to
the lower coagulation pH and subsequent reduced
lime requirements.
4. Using magnesium hydroxide as a coagulant, a much
higher degree of color removal and total organic
carbon should be achieved. This is based on a
very preliminary study with the data presented
earlier.
The discussion concerning the potential for the mag-
nesium process for the treatment of a kraft unbleached pulp
mill waste illustrates one possible application for industrial
waste treatment which should be studied in detail. Similar
discussions could be included for many other colored wastes
such as dispersed textile dye wastes, treatment of fluoride
wastes, removal of many heavy metal constituents of industrial
wastes; and silica removal to meet industrial waxier treatment
requirements. It is important that this new technology be
evaluated over a wide range of applications, first in the
laboratory and later in pilot or demonstration scale projects
if initial results are encouraging.
-------
SECTION III
INTRODUCTION
In November, 1972, the City of Montgomery, Alabama,
began drinking water produced using a totally new concept in
water treatment. This new process utilizes chemical recycle
and recovery to eliminate waste discharges and reduce the cost
of water treatment. The project at Montgomery was sponsored
by the Environmental Protection Agency, the American Water
Works Association Research Foundation and the Montgomery Water
and Sanitary Sewer Board. The study began in pilot scale and
culminated in a successful plant scale application producing
five million gallons of water per day.
The development work for this system of water treat-
ment began in the 1950's in Dayton, Ohio. Dr. A. P. Black,
working with the City of Dayton to reduce the waste sludge
from the water treatment plant, developed a technique for the
separation of magnesium hydroxide from the calcium carbonate
component of the sludge. Dayton's water supply is obtained
from clear well water very high in calcium and magnesium hard-
ness. The softening sludge produced is very high in-magnesium
hydroxide which had to be separated prior to lime recalcination,
Carbon dioxide produced in lime recalcination is used to sel-
ectively dissolve the magnesium hydroxide as the soluble bi-
carbonate. The clear magnesium bicarbonate solution is sep-
arated by thickening and discharged to a nearby water course.
Lime recalcination with sludge carbonation, begun in
1957, has been operating very successfully resulting in the
elimination of waste sludge discharge and at the same time
greatly reducing the chemical cost of water treatment.2 How-
ever, Dayton has been advised by the State of Ohio that this
clear magnesium bicarbonate discharge represents a pollution
problem, due to the high dissolved solids, that should be
eliminated. Dr. Black found after extensive laboratory and
pilot scale work that extremely pure magnesium carbonate could
-------
be easily and inexpensively precipitated from the magnesium
bicarbonate liquor.3.
During this same time period, Dr. Black discovered
that froth flotation provided a highly selective method of
separating relatively pure calcium carbonate from clay, silt,
or other common raw water contaminants. He found this to be
true only if the coagulant used has been removed prior to the
flotation process.
Another discovery was that the magnesium carbonate
produced from the Dayton plant was an excellent coagulant for
water and waste water and that it could be recovered and re-
cycled. Drs. A. P. Black and C. G. Thompson expanded the
development of this technology in laboratory studies sponsored
by E.P.A. Project 11060 ESW at the University of Florida. It
was found that this coagulant compared favorably with alum
treatment for a large number of natural waters studied in the
laboratory.4 / 5 / 6
These four basic discoveries separation of mag-
nesium hydroxide from calcium carbonate; flotation of calcium
carbonate from raw water impurities; the use of magnesium as
a recycled coagulant; and the production of magnesium carbonate
from the sludges of waters high in magnesium concentration
meshed together to produce an entirely new system of water
treatment. This coagulation system is a unique combination
of water softening and conventional coagulation. Sufficient
lime slurry is added to a water containing magnesium carbonate
or to which magnesium carbonate has been added, precipitating
both magnesium hydroxide, which has properties similar to
aluminum hydroxide, and calcium carbonate. Carbpnation of the
sludge selectively dissolves the magnesium hydroxide as mag-
nesium bicarbonate which can be recovered by thickening and
vacuum filtration for recycle and reuse. The filter cake,
composed of calcium carbonate and clay, is reslurried and the
calcium carbonate floated off for recalcination. The carbon
dioxide produced in-the recalcination is used both for sludge
-------
carbonation and finished water stabilization. The flotation
underflow, clay, is dewatered and disposed of as landfill.
There are three general applications of the processes
involved:
1) The use of magnesium as a coagulant with the recycle
of magnesium bicarbonate and sludge dewatering as an
integral part of the process. This would be applicable
to those waters relatively low in magnesium content with
insufficient lime usage to consider lime recovery. The
flow diagram is illustrated in Figure 1. Table 1 il-
lustrates a number of cities whose raw water character-
istics fall into this category.
2) Magnesium recycle using flotation for calcium car-
bonate beneficiation prior to lime recovery. The carbon
dioxide produced in lime recovery is used for sludge car-
bonation and finished water stabilization. The impurities
separated by flotation would be dewatered and disposed of
as landfill. This would be applicable for waters mod-
erately high in hardness with sufficient lime usage to
make recalcination economically feasible. This process
is illustrated in Figure 2 while Table 2 lists represen-
tative cities for this category along with their raw water
characteristics.
3) Precipitation of the magnesium present in the hard
raw water, use of lime recovery with flotation benefi-
ciation, and magnesium carbonate production. This, of
course, would be applicable to waters high in magnesium
content with sufficient lime usage to consider lime
recovery. The units required are shown in Figure 3. Table
3 illustrates typical cities in this category.
The primary emphasis of this new water treatment
process is the elimination of sludge disposal problems by the
recovery and reuse of the three (3) water treatment chemicals
used - lime, carbon dioxide, and magnesium.
-------
CO2 STORAGE
STABILIZATION
J
WATER
%UMPLE Mg (HC03)2 STORAGE
CARBONATION - - - THICKENER
SLUDGE FILT$ATE| SLUDGE UNDERFLOW
TO WASTE
CAKE TO LANDFILL
VACUUM FILTER
FIGURE 1. MAGNESIUM RECYCLE MAGNESIUM PROCESS FLOW DIAGRAM
-------
TABLE 1. CITIES TREATING SOFT SURFACE WATERS(a)
CATEGORY 1
Chemical
Characteristics
City
Baltimore
Albany
Bridgeport
Tulsa
Providence
Newark
Lynn, Mass.
Richmond
Norfolk
Atlanta
Birmingham
Mobile
Montgomery
Savannah
Shreveport
Jackson
Charlotte
Greensboro
Source of Supply
Three Rivers (Imp.)
Imp. Supplies
Imp. Supplies
Imp. Supplies
Pawtuxet River
Imp. Rivers
James River
Two Impoundments
Chattahoochee River
Lake Purdy Imp.
Big Creek Imp.
Tallapoosa River
Abercorn Creek
Cross Lake
Pearl River
Catawba River
Imp. Creeks
Mg++
(b)
2-3
3
1
2
<1
3
2
5
1
<1
<1
4
4
1
1
2
CH
(c)
35
23
9
86
5
17
34
28
14
7
3
17
25
16
16
26
TH
(d)
43
43
25
86
10
19
40
52
14
7
6
18
42
35
13
30
Turbidity
Avg.
<-!
5
-
7
<^ 1
-
44
8
27
-
50
30
17
60
25
54
Max.
3
15
-
13
"X 1
-
274
19
200
-
Ill
43
27
1000
142
340
Min.
0.1
0
-
4
\1
-
10
3
5
-
32
21
8
8
5
3
(a)All data compiled from annual reports and/or U.S.G.S. Water Supply
Paper 1812
(b)Magnesium as Magnesium
(c)Calcium Hardness
(d)Total Hardness
11
-------
RAW WATER
Mg(HC03)2 STORAGE
RECYCLE
STABILIZATION
NJ
CaO
THICKENER
REPULP
KILN
FLOTATION
TURBIDITY
FIGURE 2. LIME RECOVERY MAGNESIUM PROCESS FLOW DIAGRAM
-------
TABLE 2. CITIES TREATING MODERATELY HARD, TURBID SURFACE WATERS
CATEGORY 2
Chemical
Characteristics
City
Chicago
Cleveland
Detroit
Milwaukee
Toledo
Erie, Pa.
Buffalo
Philadelphia
Philadelphia
Washington, D.C.
Pittsburg, Pa.
Pittsburg, Pa.
Louisville, Ky.
Pater son, N.J.
Grand Rapids
Rochester, N.Y.
Evansville, Ind.
Akron , Ohio
Chattanooga
Nashville
Youngs town
Dallas, Texas
Dallas, Texas
Ft. Worth
Cincinnati
Corpus Christi
Tampa
Gary
Source of Supply Mg++
(b)
Lake Michigan
Lake Erie
Detroit River
Lake Michigan
Lake Erie
Lake Erie
Lake Erie
Delaware River
Schuylkill River
Potomac River
Allegheny River
Monongehela River
Ohio River
Several Streams
Lake Michigan
Lake Ontario
Ohio River
Cuyahoga River
Tennessee River
Cumberland River
Meander Creek (Imp.)
Impounded
Lakes
Imp. Lakes
Ohio River
Nueces River
Hillsboro River
Lake Michigan
11
7
7
10
8
10
9
6
15
8
10
5
10
6
11
10
10
7
5
8
6
6
7
8
9
6
6
11
CH
(c)
108
94
80
108
89
92
95
34
65
70
6
4
74
51
109
92
70
74
52
65
36
119
110
128
40
119
106
108
TH
(d)
128
127
100
131
186
121
131
67
153
101
120
112
131
69
130
127
136
107
73
81
86
164
152
139
137
164
125
128
Turbidity
Avg.
15
9
11
4
9
12
22
27
49
139
-
101
10
6
6
102
5
25
29
-
62
49
22
70
62
Max.
160
140
20
38
40
200
36
85
600
25
-
800
13
20
40
620
36
340
60
-
732
1120
40
1100
732
Min.
1
1
2
1
1
1
13
9
6
-
-
4
7
1
1
6
1
15
13
-
15
13
5
1
15
Seasonal organic color
5
160
1
(a)All data compiled from annual reports and/or U.S.G.S. Water Supply
Paper IS12
(b)Magnesium as Magnesium
(c)Calcium Hardness
(d)Total Hardness
13
-------
FILTERS
r&
ฑ1 it /^"""N. c I 1 AERATION PRODUCT
f ! if / \ ! f ; Mg(HC03! STORAGE HEAT CELLS DEWATERING
*! * SETTLING Vf Ol '* "m 1 RECYCLE EXCHANGER
I+.I '-. \ it 1 ILIIMlj LIIWI LIsLI 1 ฃ) 1 I a x^^x I T^ - . 1
f[ t MAGNESIUM- /I - - OjV LJ O ( ) * O" ~* ~~ *" + MgC03 3H2O
f f V / 2 1* * *' ' CARBONATIONV'' ซ,X \ ' '
t: if v^-X c B 5 l j A A
t! t x^^X ' """ -^VX J
t' 't / \ F ^ ^ X THICKENER
t! It SETTLING } L 3 ' ^
*! i*- ALUM /" --"
ฃ! ? V / r VACUUM
t: jt ^^^' \ Cฐ2 f FILTER
1 ! : = <1*K--/\
s VACUUM IV A 1 1
; .-.- - - .--' FILTER '-* V /V^,,^,| | REPULP
, , *., .^ jf ]r-*C-nT, ___, ;
CaO ;-- - 1 .:-/\( y *-- - -*.W,,.,J
^~*^^ FLOTATION
KILN ! PLUIAIIUIN
\
''
TURBIDITY
FIGURE 3. LIME AND MAGNESIUM RECOVERY MAGNESIUM PROCESS FLOW DIAGRAM
-------
TABLE 3. CITIES TREATING HARD TURBID SURFACE WATER
CATEGORY 3
Chemical
Characteristics
Turbidity
City
Des Moines
Kansas City, Mo.
Kansas City, Ka.
Flint, Mich.
Minneapolis
St. Paul
Omaha
Columbus
Columbus
St. Louis
St. Louis
Oklahoma City
Fort Wayne, Ind.
Austin, Texas
Phoen ix , Ar i z .
Lima , Ohio
Phoen ix , Ar i z .
Topeka , Ka .
New Orleans
St. Louis County
Source of Supply
Racoon River
Missouri River
Missouri River
Flint River
Mississippi River
Mississippi River
Missouri River
Scioto River
Big Walnut Creek
Missouri River
Missouri River
Lake Hefner
St. Joseph River
Colorado River
Salt River
Upland Res.
Verde River
Kansas River
Mississippi River
Missouri River
Mg++
(b)
33
16
13
24
16
10
23
26
15
17
17
26
20
19
15
23
14
23
11
17
CH
(0
244
163
172
208
158
164
172
159
92
153
154
143
225
155
122
136
144
203
108
145
TH
(d)
331
218
231
276
185
178
245
272
152
208
206
246
279
187
205
252
184
292
128
208
Avg.
50
800
810
15
7
1
280
40
13
350
383
6
75
10
-
-
-
912
5
322
Max.
1330
1800
4800
23
60
2
780
110
28
1750
2500
6
735
91
-
-
-
1120
160
2195
Min.
1
70
10
4
1
0
15
15
3
20
20
6
30
6
-
-
-
375
1
0
(a)All data compiled from annual reports and/or U.S.G.S. Water Supply
Paper 1812
(b)Magnesium as Magnesium
(c)Calcium Hardness
(d)Total Hardness
15
-------
PROJECT ORGANIZATION
The E.P.A. Demonstration Project 12120 HMZ was a
natural outgrowth of the laboratory research reported pre-
viously, Project 17060 ESW. The Montgomery Water and Sani-
tary Sewer Board sponsored the project, however, financial
support was also obtained from the American Water Works Assoc-
iation Research Foundation. An additional E.P.A. Research
Grant award was made to the Montgomery Water and Sanitary
Sewer Board to extend the application of this project to
Melbourne, Florida. In addition, the City of Melbourne,
Florida utilized a considerable portion of the Montgomery
equipment which resulted in both an expedited project start-
up date as well as financial savings. Smith & Gillespie
Consulting Engineers, Inc., Jacksonville, Florida, Melbourne's
consultants, were directly involved in planning and carrying
out the Melbourne portion of the study and are now in the
process of designing a full scale installation for Melbourne.
PROJECT OBJECTIVES
The objectives were:
1. To evaluate the process in full scale operation as to
the technical and operational characteristics in the
treatment of both a highly colored, and a soft, highly
turbid surface water.
2. To determine if color or other raw water contaminants
release on magnesium recovery would prove to be a
problem.
3. To develop design information for all unit operations
involved.
4. To develop economic information concerning all aspects
of the process.
5. To perform selected studies in the areas of taste and
odor, heavy metals, dissolved organics and new sources
of make-up magnesium.
16
-------
SECTION IV
DESCRIPTION OF PROJECT PHASES
The project was divided into three distinct phases;
a 50 gpm pilot operation in Montgomery, a 5 MGD full scale
study in Montgomery, and a 2 MGD full scale study in Melbourne.
The Montgomery pilot studies were conducted for the purpose of:
1) Providing design information for subsequent
full scale studies.
2) Training plant operators.
3) Evaluating potential process control problems.
4) Performing special studies.
In both the Montgomery and Melbourne full scale
studies, parallel treatment with the alum process using essen-
tially identical units was also accomplished. In a practical
sense, in each location these studies resulted in the simul-
taneous operation of two water treatment plants using drama-
tically different processes. This was accomplished with
existing personnel in both applications.
PILOT PLANT DESCRIPTION
MONTGOMERY, ALABAMA
The pilot plant operation began in November, 1971
and the studies were concluded in September of 1972. A photo-
graph of the pilot facilities is shown in the Appendix.
The flow sheet for the pilot plant is shown in Figure
4. The major equipment utilized consisted of the following:
10 ft. diameter reactor-clarifier
5 ft. diameter thickener
dual cell 15" X 15" carbonator (Galigher #15
flotation cells)
17
-------
CD
RAW WATER-
SETTLED ALUM
TREATED WATER
,, FROM EXISTING PLANT
[7 IJ
^ }~ FILTERS {
CHEMICAL STORAGE j i^o^ToiFlii j L~~V
1
STABILIZED WATER
1
EQUIPMENT ROOMJ |"~
_ L_
T-ENGINE) i 1 1
<5&p lrป-
RAPID MIX r^o* || UN
^y ^- ICฐJ '^ "T "' rL
X^'''''^"^^-^^/ >v j CARBONATOR-^
X^SETTLING / >\ \ | ^
CORROSION L. !
TEST AREA |^RA1N l_
LABORATORY
I
r
I
DER
OW
^==F=^,
STABILIZATION
FIGURE 4. MAGNESIUM DEMONSTRATION PILOT PLANT LAYOUT
-------
Wallace and Tiernan A747 diaphragm solution
pumps
(2) 1-1/2' X 1-1/2' pilot filters using sand
and anthracite media
Continuously recording turbidmeter
7.5 horsepower natural gas engine
Raw water was obtained prior to pre-chlorination
and regulated by a control valve to maintain the desired flow
rate. Recycled magnesium bicarbonate, make-up magnesium sul-
fate, and lime were added to the raw water in successive order.
Recycled sludge from the clarifier underflow was added to the
rapid mix. The settled water was stabilized using the exhaust
from the natural gas engine. Two stage settled water .stabi-
lization was used during a portion of the study by introducing
carbon dioxide into the transfer line between the clarifier
and filter.
The clarifier underflow was carbonated using pure
carbon dioxide, in a Galigher #15 dual cell flotation machine.
During periods of the study, exhaust gas was also used for
sludge carbonation. The 5 ft. diameter thickener was used for
solids-liquid separation, the overflow magnesium bicarbonate
recycled to the raw water and the underflow to disposal or
special studies.
Recycled sludge was provided for the following pur-
poses:
1) Recycled calcium carbonate increases magnesium
precipitation kinetically as well as quantitatively as reported
by several early investigators.7'8'9'10
2) A portion of the magnesium hydroxide fraction
of the sludge reacts with the recycled magnesium bicarbonate
as well as the natural bicarbonate alkalinity and carbon
dioxide in the raw water. This solubilized magnesium carbon-
ate is effective for coagulation when reprecipitated; however,
19
-------
some coagulated turbidity is also released. The overall
effect is difficult to evaluate but is generally considered
to be of some value.
3) The preformed calcium carbonate recycled acts
as a seed or nucleus for precipitation preventing a build-up
on mechanical equipment.
4) The excess causticity in the sludge water, pH
11.40, reduces the lime requirements slightly. The precipi-
tation reactions occur rapidly and produce small dense floc-
culent particles. Even at maximum flocculation speeds the floe
tends to settle from suspension.
MONTGOMERY FULL SCALE STUDIES
Figure 1 is the flow diagram of the Montgomery plant
as converted for the study. This plant was an excellent faci-
lity for this project as only minor alterations were required
to produce parallel plants with almost identical treatment
units. Rapid mixing could not be provided for the alum process,
but jar tests indicated that with the ample time provided in
the flocculator, floe formation was not affected. A partial
analysis of Montgomery's raw water is shown in Table 4.
TABLE 4. TYPICAL RANGE IN RAW WATER CHARACTERICS
TALLAPOOSA RIVER, MONTGOMERY, ALABAMA
Alkalinity Hardness Magnesium Color Turbidity
pH (mg/1) (mg/1) (mg/1) (mg/1) (rog/1)
6.6-7.0
10/22
(As CaC03)
10-22 0-5
(Pt-Co)
5-60
(JTU)
2-300
The description of the plant facilities is in the
order of occurrence.
20
-------
RAPID MIX AND FLOCCULATOR
Figure 5 illustrates the recycle and chemical feed
points using the two rapid mixers in series which provides a
total detention time of four minutes at a rate of 5 MGD. Re-
cycled magnesium bicarbonate was added to the raw water immed-
iately prior to rapid mixing while uncarbonated recycled sludge
and magnesium sulfate* were added in rapid mixer #1. Lime was
added between rapid mixers #1 and #2 adjusting the pH to the
desired value.
Lime feed was controlled automatically using a pH
probe in rapid mixer #2, coupled to a pH controller and S.C.R.
controlled pump as shown in Figure 6. Flocculation was carried
out using conventional reel type variable speed flocculators
normally operated at the maximum speed.
SETTLING-CARBONATION
The Montgomery plant utilizes conventional horizontal
settling basins with mechanical sludge removal in the first
half. Approximately two-thirds of the basin was used for set-
tling with the remaining third used for two stage stabilization,
Liquid carbon dioxide was metered manually into the settled
water, dispersed through 1" PVC pipe drilled with small holes
approximately 2 ft. apart. Baffles of polyethylene film were
installed to prevent mixing back to the settling zone.
The purpose of the two stage carbonation is to first
convert the hydroxide to carbonate alkalinity, precipitating
calcium carbonate. For this reaction, the pH was held at 10.3.
*Magnesium sulfate was used as a make-up source of magnesium
as no magnesium carbonate tri-hydrate was available at this
time. The make-up dosage was quite low, less than 5 mg/1,
thus, the noncarbonate hardness addition was minimal.
21
-------
RAW WATER
RECYCLED
Mg(HC03)2
RECYCLED -
SLUDGE
ป
s,
s
V,
V
v
rn ,_. PH PROBE
il \
^^. ^^_ x. ^V. x. %
-*-o
V
X
X
X
X
x
x
x
X
x
x
x
o
X
s
V
s
X
x
s
s
^
N
X
X
X
X
X
X
X
x
X
s
0
o
X
x
X
x
x
x
X
x
x
x
X V X X X
s
X
X
s
s
\
s
S
\
LIME *
TREATED WATER
-I
RECYCLED SLUDGE
.MgSO4
.LIME
pH PROBE
s
7-
/
/
Lrf
za
to
If S S S
n
LJ
////////'
f
7
(
iฃ
sss.
m
L
*
JL
a
n
u
SS///S/SS
?
^//s///
/
/
A
TREATED WATER
-i
RAW WATER
FIGURE 5. DETAILS OF RAPID MIX UNITS AND CHEMICAL ADDITIONS
MONTGOMERY, ALABAMA
-------
NJ
CU
RECORDER CONTROLLER
RAPID MIX
LIME FEED PUMP LIME SLAKER
FIGURE 6. FLOCCULATION pH CONTROL SYSTEM - MONTGOMERY
-------
Very little of the calcium carbonate formed settled, however,
the solid phase is relatively stable and does not redissolve
upon final pH stabilization just prior to filtration. The
carryover of calcium carbonate onto the filter does not
shorten the length of filter run and does not pass through
the filter. Proper adjustment of the settled water pH
prevents calcium carbonate from precipitating on the sand
in the filter. Precipitated calcium carbonate carried onto
the filter was easily removed on backwashing.
FILTRATION
Settled, stabilized waters from the alum and mag-
nesium processes were separated and filtered in identical sand
filters, generally at a rate of 1 to 2.5 gallons per square
foot per minute. One of the four filters used on the magnesium
process was converted to a dual media filter, replacing three
inches of sand with anthracite having an effective size of 1.2 mm,
MAGNESIUM RECOVERY AND SLUDGE HANDLING
Figure 7 illustrates the units comprising the sludge
recovery system. Sludge was pumped at a controlled rate into
the carbonation cells using a variable speed Moyno pump. Four
10 cubic feet flotation cells were used for sludge carbonation.
Again pure carbon dioxide was used, the feed being automated
as shown in Figure 8. Carbonated sludge was pumped into a
10 feet diameter thickener with the overflow returned to the
raw water using an intermediate 1800 gallon storage tank. The
recycled magnesium bicarbonate was pumped at a controlled rate
to give the desired coagulant dosage. The thickener underflow
was vacuum filtered with a 3' X 3' drum filter? The filtrate
*Envirotech Corporation, Salt Lake City, Utah
24
-------
SETTLED SLUDGE
to
Ln
DEWATERED
CAKE
STORAGE
CARBONATION CELLS
Mg (HC03)2TO RAW WATER PUMP
PUMP
CARBONATED
SLUDGE
THICKENER
VACUUM
FILTER
ELECTRICAL PANEL
SUPERNATANT
THICKENER UNDER FLOW
DRYING BEDS
FIGURE 7. MONTGOMERY WTP SOLIDS HANDLING FACILITIES
-------
8.5% ENGINE EXHAUST
KIliN EXHAUST ฃAS
i
,02 .03 .04.05.06.07-08.09.1 2 -3 .4 .5 .6 .7 .8-9 1.
CO2 PRESSURE, ATMOSPHERES
FIGURE 8. SOLUBILITY OF MAGNESIUM AS A FUNCTION OF CO2 PARTIAL PRESSURE
-------
was pumped to the magnesium bicarbonate storage tank and the
filter cake hauled to a landfill.
There are several reasons why pure carbon dioxide
should be considered for use in the smaller plants not re-
covering lime. The rate at which carbon dioxide solubilizes
magnesium has been found to be first order with respect to
the partial pressure of the carbon dioxide.11 In addition,
pure carbon dioxide will dissolve approximately 25,000 mg/1
of magnesium bicarbonate, as shown in Figure 8, considerably
more than the lower percentage carbon dioxide produced from
on-site generation. The feed of liquid carbon dioxide is
simpler, more flexible and easier to automate.
Carbon dioxide feed was automatically controlled to
achieve a pH of 7.3, as shown in Figure 9. Near 100% effic-
iency is possible due to the very fine bubbles produced and
the high driving force between the caustic sludge and the
carbonic acid. At pH values below 7.3 the reaction has es-
sentially gone to completion resulting in the loss of carbon
dioxide to the atmosphere. The carbon dioxide bubbles cause
foaming which is greatly accentuated by the slightly surface
active organic color released from the sludge on carbonation.
This foaming serves as a good indicator of excess carbonation
and can be used for visual pH control of the process.
MELBOURNE FULL SCALE STUDIES
Both Montgomery and Melbourne presently use the
conventional alum water treatment process; however, the raw
waters treated vary drastically in chemical and physical
characteristics. Table 5 illustrates typical ranges in raw
water characteristics for Melbourne's Lake Washington water.
27
-------
oo
10-50 mA SIGNAL pH METER
I
CONTROLLER
RECORDER
SLUDGE
n
CURRENT TO
AIR TRANSDUCER
L_J I L
CARBONATOR
SLUDGE
O
AIR VALVE
CO,
FIGURE 9. SLUDGE CARBONATION pH CONTROL SYSTEM - MONTGOMERY
-------
TABLE 5. TYPICAL RANGE IN RAW WATER CHARACTERISTICS
LAKE WASHINGTON, MELBOURNE, FLORIDA
PH
6.8-7.8
Alkalinity Hardness Magnesium Color Turbidity
(mg/1) (mg/1) (mg/1) (mg/1) (mg/1)
(As CaCO3>
25-100 40-200
(Pt-Co)
6-50 60-300
(JTU)
a
aNormally zero, but under severe storm conditions can increase
to 30-50 JTU.
The chemical and physical characteristics of Lake
Washington water are consistent on a daily basis. The water
during the seasonal "dry" period is much harder and lower in
organic color -than during the "wet" season.
Montgomery typically uses from 20 to 30 mg/1 of alum,
coagulating in the pH range of 6.0 to 7.0. Melbourne uses as
much as 130 mg/1 of alum with coagulation in the pH range of
5.1 to 5.3. In addition, due to the high dissolved organics
in the Melbourne water, high dosages of activated carbon are
required along with large dosages of chlorine added to the
finished water. Thus, while both plants would be termed "alum
treatment plants", they represent different types of raw waters
and treatment considerations.
PLANT PHYSICAL FACILITIES
Figure 10 is a layout of the Melbourne water plant
converted to include the magnesium process in half of the plant,
The Melbourne plant facilities differed from the Montgomery
facilities primarily in that:
1. Vertical flocculators were used-versus the Mont-
gomery horizontal flocculators.
2. Upflow clarifiers designed -for an overflow rate
of .5 gallons/sq.ft./minute versus six (6) hour
retention horizontal, settling basins in Montgomery.
29
-------
ALUM SLUDGE
00
O
RAW WATER PRESSURE MAIN
RAW WATER INTAKE
SLUDGE
LAGOON.
FILTER WASHWATER
ALUM SLUDGE
MAGNESIUM
TREATMENT
FLASH
MIXERS
REACTOR Mg(HC03)2
2 MILLION GALLON
GROUND STORAGE
TANK
VACUUM FILTERS
PUMP
HIGH SERVICE
PUMPING
O o
SLUDGE MAGNESIUM
THICKENING BICARBONATE
STORAGE
ALUM TREATMENT REACTOR
1
2
LLJ
3
4
FILTERS
FIGURE 10. LAYOUT OF MELBOURNE WATER PLANT CONVERTED TO INCLUDE THE MAGNESIUM PROCESS
-------
3. Manual feed of carbon dioxide and lime was provided
at Melbourne.
4. Melbourne was provided with single stage finished
water stabilization versus two stage stabilization
at Montgomery.
The carbonation cells, thickener, recycle pumps,
vacuum filter, and other miscellaneous equipment were shipped
from Montgomery to Melbourne, so that little change was made
in the magnesium recovery and recycle system. Melbourne's
North Water Treatment Plant is constructed on a small hill.
This elevation differential was used advantageously in the
study to minimize pumping and to utilize gravity flow where
possible.
A coagulant aid, either Dow AP30 or American Cyan-
amid 845A, both high molecular weight anionic polymers was
added to the flocculator in very dilute solution. Typical
dosages ranged from 0.1 to 0.3 mg/1.
PROJECT LIMITATIONS
The conversion of both plants was accomplished with
a very limited budget on a temporary basis. This resulted in
excessive mechanical down-time, particularly in Montgomery,
and excessive labor requirements, generally in the early pro-
ject stages.
In Melbourne, an unavoidable limitation was that
1973 was a "wet" year and the raw water hardness did not
increase in the Fall as expected. Past records indicated that
both a very soft, high-colored water and a hard, moderately-
colored water would be treated during the project period. The
"soft", highly-colored water treated during the entire pro-
ject proved, as expected from previous laboratory studies,
to be both the most challenging and expensive to treat. This
31
-------
as important to the overall evaluation program since during
dry years, such as 1971, the water is hard most of the year.
32
-------
SECTION V
RESULTS AND DISCUSSIONS
PILOT PLANT STUDIES
Pilot studies were conducted in Montgomery, Alabama
from November, 1971 until October 1972 using the facilities
discussed in Section IV. Initial operation evaluated the
use of liquid alum as a coagulant to compare the pilot plant
performance with the full scale plant operation. It was found
that only 10 gpm of raw water could be treated with alum without
excessive floe carryover to the filters. These studies were
conducted over a two week period.
The pilot plant system was thoroughly flushed and the
magnesium process placed into operation. Operation was con-
ducted initially on an intermittant daily basis; however,
continuous operation was soon undertaken. Studies were in-
itially undertaken for each of the various operations or
processes involved, such as sludge carbonation, clarification,
finished water stabilization, etc. Although all units were
operating, data collection and special attention were given
only to the specific process under study.
After each portion of the water treatment system
had been studied and adjustments made as required, the pilot
plant was operated as an integral system.
PILOT PLANT OPERATION
The pilot plant was typically operated treating
raw water at the rate of 25 to 50 gpm. During normal daylight
hours supervision was continuous. At night, water plant
operators would hourly inspect the mechanical equipment, per-
form the necessary analyses and make the necessary chemical
feed adjustments.
33
-------
The sources and sinks of magnesium are extremely
important in determining optimum process operating conditions.
The sources of magnesium include the magnesium present in the
raw water as well as any magnesium added. The sinks include
magnesium losses in the dewatered sludge and magnesium present
in the treated water. The magnesium loss in the finished water
is largely affected by the pH of coagulation although finely
divided magnesium hydroxide floe present as clarifier carry-
over will be dissolved on stabilization. The relationship
between magnesium solubility as a function of pH is illustrated
in Figure 11 for theoretical, jar test,, and pilot plant
conditions.
Table 6 illustrates typical data collected and
operating conditions. Calcium carbonate turbidity, either
carryover from clarification or formed during pH adjustment,
was found to be completely removed by filtration without
causing unduly short filter runs. In order to better evaluate
process performance it was desirable to distinguish-between
true turbidity, the type found in the raw water, and calcium
carbonate turbidity. This is referred to as acidified tur-
bidity. Levels of less than 1.0 FTU were commonly experienced.
Table 7 illustrates the effect of drastically changed
raw water quality on both the alum and magnesium process. At
a constant magnesium dosage of 50 mg/1 and coagulation pH of
11.3, the pilot plant produced a high quality product with
almost no supervision. The alum process was upset by the
change in raw water quality, even with constant supervision.
DISINFECTION STUDIES
The effect of high pH on bacterial and virus sur-
vival has been well documented by other investigations. -12'13'1
Limited studies were conducted to verify the effect of high pH
34
-------
I
C"5
o
o
03
O
Q,
CL
CO
O
(f)
c/)
UJ
Z
f_n
JAR TESTS
PILOT PLANT
10.60 1070 10.80 10.90 11.00 11.10
COAGULATION pH
11.30 11.40 11.50
FIGURE 11. COMPARISON OF THEORETICAL SOLUBILITY OF Mg (OH)Z WITH OBSERVED JAR TEST AND PILOT PLANT VALUES
-------
TABLE 6. TYPICAL PILOT PLANT RESULTS
(Analyses performed each hour, averages shown)
u>
a\
Date/
Time
S/14
I2TO
1800
8/15
0030
0630
1200
1800
8/16
OuOO"
0630
1200
1800
8/17
0600
1200
1800
8/18
0000
0630
~Raw
Turbidity
(FTU)
5.1
4.7
5.3
3.5
5.6
4.7
5.4
4.9
4.3
4.6
5.2
4.6
5.0
5.2
3.9
Coag-
ulation
pH
11.4
11.3
11.3
11.3
11.3
11.2
11.3
11.2
11.3
11.1
11.0
11.1
11.3
11.3
11.4
11.4
Carbonated
Sludge
PH
7.38
7.16
7.05
7.10
7.21
7.91
7.20
7.28
6.21
7.5
7.4
7.3
7.2
7.2
7.4
Stabilized Water Filtered Magnesium
pH
7.1
8.2
7.9
7.9
9.0
8.5
7.9
7.9
8.2
8.4
7.5
7.7
8.5
8.8
8.3
7.7
Turbidity
(FTU)
0.6
0.5
0.6
1.9-
0.8
1.0
0.6
0.9
3.3
5.8
5.5
6.5
Acid Turb.
(FTU)
0.4
0.3
0.4
0.2
0.5
0.3
0,3
0.6
1.0
2.3
1.3
0.8
__
Alkalinity.
COl HC03
0 144
32 118
0 107
0 109
32 117
26 112
0 92
0 87
56 . 87
20 89
0 77
16 66
0 61
19 63
20 74
0 81
Turb.
(FTU)
.08
.06
.05
.05
.05
,05
.06
.07
.08
.07
.06
.06
Alkalinity
C03 HC03
0 121
0 108
0 101
0 117
0 110
0 90
0 85
0 97
12 94
0 82
0 82
0 60
0 75
0 81
0 95
Filtered
Alum Water
Turbidity
(FTU)
.30
.24
.17
.05
.05
.07
.08
.07
.09
.12
.09
.06
.06
.12
.05
-------
TABLE. 7. PILOT PLANT RESULTS DURING RAPID RAW WATER QUALITY DETERIORATION
(Analyses performed each hour, averages shown)
Date/
rn *l ปwj*ป
Time
Tlfff
1300
1500
1700
1900
2100
2300
8/1
100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
Raw
rrii.uVs4 iH A ^.r
rurDiuity
(FTU)
. 40
32
36
53
75
200
245
55
55
50
45
40
40
40
54
Coag-
ulated
pH
11.2
11.2
11.2
11.1
11.1
11.1
11.1
11.2
11.2
11.2
11.2
11.3
11.0
10.7
10.7
10.7
10.7
10.9
11.0
Carbonated
Sludge
PH
7.1
7.2
7.6
7.5
7.4
7.5
7.5
7.5
7.5
7.5
7.5
7.4
7.4
7.3
7.3
7.4
7.4
9.8
10.4
Stabilized Water
pH
9.2
9.2
9.6
9.3
8.4
7.5
7.2
7.3
7.3
9.5
9.5
9.8
9.7
7.7
7.4
7.2
7.3
7.2
7.1
"
Turbidity
(FTU)
1.8
1.5
3.5
2.4
1.5
1.4
1.4
1.3
1.4
3.0
2.0
3.2
2.8
1.4
1.0
1.7
3.9
2.7
3.0
Acid Turb.
(FTU)
0.5
0.5
0.5
0.4
0.6
0.5
1.0
0.3
1.0
1.5
1.6
1.2
Alkalinity
COf HC03
16 78
24 74
44 44
24 60
8 68
0 76
0 74
0 68
0 76
45 48
46 48
64 38
52 38
0 82
0 76
0 82
0 74
0 72
0 74
Filtered Magnesium
Turb.
(FTU)
0.10
0.06
0.05
0.15
0.10
0.22
0.31
0.28
0.40
0.30
Alkalinity
CO^ HC05
0 84
12 74
28 32
8 52
4 68
0 82
0 66
0 76
0 70
0 72
28 28
28 36
32 38
10 78
0 85
0 92
0 84
0 78
0 78
Filtered
Alum Water
Turbidity
(FTU)
2.00
>3.00
> 3.00
3.00
2.80
2.00
1.00
1.00
-------
on coliform survival. In general, these studies consisted of
adding various Ca(OH)2 dosages to 1 liter jars of raw water to
obtain a pH range of 10.5 to 11.7. Samples were collected from
each jar at predetermined time intervals and analyzed for total
coliform organisms. A summary of these laboratory studies is
shown in Figure 12. Table 8 includes all laboratory coliform
disinfection experiments.
The raw water source for the pilot plant was obtained
prior to pre-chlorination. When operating at 50 gpm a hydraulic
retention time of approximately two hours allowed complete dis-
infection of coliform organisms when coagulation at a pH above
11.0.
It should be pointed out that while the high pH is
effective, it is not nearly as effective as free chlorine at
the normal pH range of raw water. A pre-chlorine dosage of
1.5 mg/1 resulted in complete disinfection with less than a
30 second contact time.
SOLIDS HANDLING
This section of the report will be limited to
sludge thickening and vacuum filtration. The pilot plant
was used to generate sufficient solids for a thorough labo-
ratory evaluation to develop design criteria and predict pro-
cess performance.
Considerable data exists for thickening and filtering
pure calcium carbonate slurries; however, data for clay-calcium
carbonate slurries are limited. The higher the percentage of
calcium carbonate present the more readily the sludge thickens
and dewaters. The characteristics of the Montgomery raw water
are such that the only calcium carbonate produced results from
the recycle of magnesium bicarbonate. The ratio of calcium
carbonate to clay will vary from summer to winter months as
the turbidity in the raw water changes. The sludge produced in
the treatment of Montgomery's water should represent the most
difficult situation to be encountered.
38
-------
TABLE 8. SUMMARY OF COLIFORM SURVIVAL LABORATORY STUDIES
Lab Studies - Montgomery, Alabama
(total coliform per 100 m.l.)
>H
Time
(min. )
0
3
5
6
10
11
13
15
20
30
40
60
80
10.6
900
350
80
15
3
10.8
400
400
150
10.9
900
100
60
5
0
*~
10.95
400
100
20
0
11.2
400
200
100
20
0
11.3
900
50
20
0
11.4
1100
300
350
250
100
5
11.45
800
560
360
190
65
18
11.5
1100
700
100
150
20
0
39
-------
(Coliform level 9OO/1OOml. pH adjusted with
10 2O 3O 4O
TIME/MIN.
"1 :
V -
1
-
60
70
FIGURE 12. EFFECT OF pH ON COLIFORM SURVIVAL
LABORATORY STUDIES
40
-------
A number of bench scale thickening studies were
performed during the pilot plant study. Figure 13 illustrates
the relative differences between the thickening characteristics
of the alum sludge and the carbonated pilot plant sludge.
The uncarbonated sludge thickened to a lesser degree
due to the magnesium hydroxide present. The sludge concen-
tration from the clarifier, however, exceeded 15% solids during
most of the study period.
Leaf filter tests were run to determine design
criteria for the full scale vacuum filter. A number of cloths
were evaluated and a multi-filament, polypropylene, high air
flow rate cloth was found most effective in producing a clear
filtrate, high cake yield, and relatively clean cake discharge.
Figure 14 summarizes a number of leaf filter tests and illus-
trates the effect of feed solids concentration on the fil-
tration rate. During this study period, the sludge was com-
posed of 70% calcium carbonate, 25% clay or inert content,
and 5% magnesium hydroxide.
The thickener and vacuum filter design are ob-
viously related. Each situation dictates an optimum design
to minimize costs and labor requirements.
COLOR REMOVAL STUDIES
Organic color release upon carbonation will not
present a problem for the application of the magnesium pro-
cess in Montgomery. However, for the more highly colored
waters and in the treatment of certain colored industrial
wastes, this could become a significant problem. Water
plants treating high magnesium waters, producing magnesium
carbonate as a by-product, also present a problem with the
coloring of the magnesium carbonate.. Thus, color removal
prior to magnesium carbonate precipitation would increase
the quality of the product. For these reasons, decolor-
41
-------
80
9.9% INITIAL
70
MAGNESIUM PROCESS
ro
t 60
\
50
V)
GO
O 40
5
2 30
WJ
o
O on
U) ^U
ALUM 1.9% INITIAL
FINAL-40%
10
J FWAL-e.6%
5 I 10 15
20
25
30
35
AVERAGE UNDERFLOW CONCENTRATION {% SOLIDS)
40
45
FIGURE 13. THICKENING CHARACTERISTICS OF ALUM AND MAGNESIUM STUDIES
-------
D
i
i
t/j
(;!
lU
1
;
f ,
<
i
28
O ^1
J f\
20
1 O
1 0
1 (i
8
>
^^^
S
^r^
12
16 20
% SOLIDS
24 28
6
FIGURE 14. % SLUDGE SOLIDS VERSUS VACUUM FILTER RATE - MONTGOMERY
-------
ization of the magnesium bicarbonate solution was studied
using activated carbon.
Powdered FILTRASORB #400 carbon (by Pittsburg Acti-
vated Carbon) was used in this study. The studies were con-
ducted on a batch basis maintaining constant temperature by
means of a water bath. Average magnesium bicarbonate con-
centrations of 6,000 mg/1 as calcium carbonate were present
in the solution tested with no magnesium reduction found as
a result of the color adsorption. The resulting data were
plotted using the Fruendlich isotherm equation, X/M = KC1'11,
to obtain the adsorptive capacity. Tables 9 and 10 show the
data obtained in two such experiments and are plotted in
Figure 15. The only variable in these two experiments was
temperature.
At a temperature of 35ฐC, 1 gram of carbon would
completely decolorize 3,600 ml of solution while at 22ฐC, 1
gram would only decolorize 1,200 ml. Based on the 35ฐC
figure a cost of approximately $2 per million gallons of
water treated is estimated for carbon adsorption to remove
the color found in the recycled coagulant liquor in this
study. These costs are only crude estimates for the Mont-
gomery water and cannot be used for waters in general. It
would seem that carbon adsorption may represent an economical
solution where color release is a problem.
Chlorine was also investigated as a means of
decolorizing the recycled magnesium solution. As shown in
Table 11, the chlorine was also very effective.
Samples (100 ml) of the recycled solution were
dosed with chlorine stock solution to give the desired
treatment levels. After sixty minutes the samples were
filtered and color determined. Calcium hypochlorite was
used as a chlorine source.
44
-------
TABLE 9. CARBON ADSORPTION OF RELEASED ORGANIC COLOR
(Temperature = 22ฐC, 200 ml of solution used
and contact time of 20 minutes)
(M)
Carbon
(grams)
Blank
.1
.2
.3
.4
.5
(C)
Residual Color
550
282
124
68
36
23
(X)
Adsorbed Color
(grams)
0
268
436
482
514
527
X/M
2680
2180
1606
1285
1054
TABLE 10. CARBON ADSORPTION OF RELEASED ORGANIC COLOR
(Temperature = 35ฐC, 200 ml of solution used)
(M)
Carbon
(grams)
(C)
Residual Color
(X)
Adsorbed Color
(grams)
X/M
Blank
.1
.2
.3
.4
.5
425
130
91
50
38
33
0
295
334
375
387
392
2950
1670
1250
967
784
45
-------
4,000
3,000
2.000
o
CQ
< 1,000
(J
5
Q
o
no
a
O
DC
O
_l
o
< J
x
900
800
700
600
500
400
300
200
100
30 40 506070 8090100
RESIDUAL COLOR (PT.-CO. UNITS)
FIGURE 15. FRUENDLICH ISOTHERM FOR CARBON ADSORPTION OFORGANIC COLOR WITH ACTIVATED CARBON
-------
TABLE 11. USE OF CHLORINE TO REDUCE ORGANIC COLOR
Chlorine
(mg/1)
50
100
150
200
250
Original Color
(Pt-Co)
647
616
591
566
544
Residual Color
(after 60 minutes)
202
103
63
55
53
% Removal
69
83
90
91
91
CADMIUM STUDY
The effectiveness of this new process in the removal
of heavy metals was studied in both jar tests and in the pilot
plant. Cadmium was chosen because of its easy and accurate
determination by atomic adsorption as well as for the fact that
it would likely be solubilized at a pH of 7.0, the pH of sludge
carbonation. The results of jar tests are shown in Tables 12,
13 and 14.
TABLE 12. EFFECTIVENESS OF ALUM IN REMOVING CADMIUM
Alum Dosage Cadmium Residual
(ppm) (mg/1)
5 1.04
7 1.09
9 1.09
11 1.10
13 1.07
Initial cadmium level - 1.1 mg/1
Comments - Good floe formed in all jars
47
-------
TABLE 13. EFFECTIVENESS OF LIME IN REMOVING
CADMIUM FROM WATER IN JAR TESTSa
Lime Dosage pH Cadmium Residual
(ppm) (mg/1)
40
50
60
80
100
120
10.65
10.70
10.95
11.10
11.25
11.30
0.73
0.81
0.72
0.71
0.60
0.60
a1.0 mg/1 cadmium present in raw water.
TABLE 14. EFFECTIVENESS OF MAGNESIUM HYDROXIDE IN REMOVING
CADMIUM FROM WATER IN JAR TESTS
Magnesium Precipitated Cadmium Residual % Removal
(mg/1) (mg/1)
2.9 .36 58
7.5 .15 82
13.4 .05 94
21.4 .02 98
31.4 .01 99
42.2 .01 99
48
-------
Reagent grade cadmium chloride was used as a source
of cadmium in all studies. Samples taken after settling were
filtered through Whatman #40 paper prior to analysis. Uh-
filtered samples taken during the study reported in Table 15
showed similar removals.
During pilot plant studies cadmium chloride was
added continously to the raw water for a period of ten days.
The magnesium and lime dosage was 40 and 100 mg/1 respectively.
The raw water cadmium level ranged from 0.75 to 1.0 mg/1.
The settled water ranged from 0.003 to 0.007 mg/1 and the
filtered water ranged from 0.000 to 0.005 mg/1 of cadmium.
Table 14 summarizes the analytical results.
Cadmium was not released in any appreciable amounts
on carbonation regardless of the pH to which carbonation was
carried. A pH range of 6.8 to 7.7 generally resulted in a
cadmium concentration of 0.1 mg/1 or less in the recycled
magnesium bicarbonate solution.
FILTRATION STUDIES
Two identical 1.5 square foot pilot filters with
continuous turbidity monitoring equipment were made avail-
able to the project by the Taulman Company, Atlanta, Georgia.
Combinations of sand and various sized anthracite media were
evaluated as to water quality produced and operating char-
acteristics. Initial studies compared the filterability of
the alum treated water, piped from the full scale plant, with
the stabilized magnesium treated water. Later studies were
made using the proper stabilization pH, type media, and depths
of sand anthracite required.
These studies allowed the following conclusions:
1) Filtration efficiency is directly related to
49
-------
TABLE 15. PILOT PLANT RESULTS - CADMIUM STUDY
(Cadmium concentration - ppm mg/1)
Date/
Time
Raw
Water
Carbonate
Sludge
Clarified
Water
Filtered
Water
7/20:
1400
1600
0.92
0.75
7/21:
0930
1300
1510
0.94
1.00
0.78
0.005
0.007
0.003
0.005
0.005
0.000
7/25:
1300
1500
1610
0.80
0.81
0.82
0.030
0.030
0.00
0.00
0.00
7/26:
0830
1320
1530
0.55
0.60
0.12
0.12
0.030
0.060
0.00
0.003
0.005
7/27:
0930
1415
1540
0.87
0.90
0.14
0.16
0.10
0.060
0.050
0.030
7/28
0.05
50
-------
coagulation and clarification efficiency for both
the alum and magnesium process. When proper pre-
treatment has not been accomplished, filtration
will not provide adequate treatment.
2) The carryover of calcium carbonate will not
shorten filter runs or reduce the quality of the
filtered water.
3) In Montgomery, filtration of waters which had
not been stabilized below pH 9.0 resulted in calcium
carbonate precipitation on the anthracite and sand
media. Precipitation occurred more rapidly and ex-
tensively on the sand. Extremely short filter runs
were obtained under these conditions and the calcium
carbonate formed could not be washed from the filter.
These "balls" gradually worked their way into the
gravel underdrain, eventually requiring acidification
treatment of the filter. These studies provided a
severe warning as to the necessity of adequately main-
taining the proper stabilization pH in full scale
operation.
4) Maximum filter runs were obtained with four inches
of 1.2 mm anthracite media over twenty-four inches of
standard filter sand. Increase in anthracite media
depth did not increase filter performance either in
length of filter run or water quality produced.
5) In general, two filter rates were studied, 2
and 3.5 gal./sq.ft./min. The higher rate on the
average produced a slightly better water quality.
It appeared that backwash requirements were essen-
tially the same, based on percentage of the water
51
-------
produced during the run.
6) The geometry of the pilot filters was such that
backwashing was not equivalent to the full scale
filters. Side wall friction was considerably higher,
resulting in an unusual backwash pattern. Considerable
care was required to prevent backwashing of media
from the system. Backwash rates of 15 gal./sq.ft./min
were not possible, so that some of the calcium found
on the media could possibly have been removed at
higher backwash rates.
7) Finished water stabilization appears to enhance
filtration efficiency. Clarifier turbidity carryover
serves as a nucleus for calcium carbonate precipitation,
enlarging the particle size and changing the chemical-
physical properties, increasing the opportunity for
removal by filtration.
8) Calcium carbonate carryover to the filters does
not shorten filter runs and can be easily removed on
backwash. Calcium carbonate precipitation on the filter
media drastically shortens filter runs and cannot
be removed efficiently by backwashing.
MONTGOMERY FULL SCALE STUDIES
From November 1972 until June 1973 full scale eval-
uation of the Magnesium Process was conducted in Montgomery.
The Magnesium Process was found to compare favorably with the
alum process in both overall operation and water quality
produced.
During the study voluminous data were collected
at many points of the process. Figure 16 illustrates a sum4
mary of process control points and a brief discussion as to
52
-------
CO2 STORAGE
u>
RECYCLE>
PUMP/ Mg (HCO3)2 STORAGE
SETTLING
MAGNESIUM.
SLUDGE
TO WASTE
THICKENER
FILT|ATE! SLUDGE UNDERFLOW
H
CAKE TO LANDFILL
VACUUM FILTER
FIGURE 16. PROCESS CONTROL POINTS AND SAMPLING LOCATIONS - MONTGOMERY
-------
which tests were performed are listed in Table 16. Data
sheets to illustrate typical results are included in the
Appendices under Appendix A.
The full scale studies found the magnesium coag-
ulation system to be much more stable than the alum system,
particularly in the coagulation process. Under certain raw
water conditions, the alum coagulation pH must be maintained
within + 0.1 pH unit in order to treat the water satifacto-
rily. Slight variance from the optimum pH results in greatly
decreased coagulation efficiency. The low alkalinity water
used by Montgomery has a very poor buffer capacity, par-
ticularly after the addition of alum when the alkalinity
is seldom above 1 mg/1 as CaCO3. Slight changes in either
pre-lime or alum feed can affect the coagulation pH to a
large degree.
Automation of the lime feed and carbon dioxide
feed for sludge carbonation proved to be very satisfactory.
Control of both feeds are such that less than 0.1 pH from
the desired pH occurs.
Recovery of magnesium as the bicarbonate was rou-
tinely carried out at a constant rate sufficient to provide
the average coagulation requirements. When raw water con-
ditions required additional magnesium feed, make-up mag-
nesium sulfate was fed. After feeding make-up magnesium
for a period of approximately twenty-four hours, increased
magnesium content in the recovered solution eliminated the
need for make-up magnesium.
Figure 17 illustrates the relationship between
raw and settled turbidity as a function of time and mag-
nesium dosage. These results indicate an important point.
As the operators became more familiar with the process, a
significant improvement in treatment efficiency was noted.
Figure 18 shows the total and magnesium hard-
ness of the Montgomery stabilized water as a function of
54
-------
TABLE 16. CONTROL SYSTEMS AND SAMPLING LOCATION
A) Rapid Mixer #1. Total and calcium hardness were
determined on a filtered sample from which the
magnesium feed could be determined.
B) Rapid Mixer #2. Automatic pH control of lime feed.
C) Carbonation Point 1. pH measurement and manual
control of CO- rotameter to maintain a pH of 10.3.
When the pH is too low or too high, the water is
clear indicating that calcium carbonate precipitation
is not taking place.
D) Settled magnesium water flume. pH, turbidity, total
hardness, calcium hardness, alkalinities, and acid
turbidity were determined on a routine basis.
E) Filtered magnesium treated water - continuous turbidity
monitoring along with alkalinities, pH, and hardness
determined on a routine basis.
F) Carbonated Sludge - Automatic pH control of the carbon
dioxide flow along with alkalinity titrations on a
routine basis.
G) Recycled magnesium control system - alkalinities
measurement and flow control.
H) Vacuum filter - filter rates, solids inflow, filtrate
alkalinities, filter cake solids, and filter cake
composition are determined on a routine basis.
55
-------
01
RAW SETTLED (ACID)
70 T 7.0
60 - 6.0
RAW
(WEEKLY AVERAGES)
50 5.0
g
Q
s
K
D
40 - 4.0
20
10 -
30 3.0
100
50
O
u
UJ
(9
M
O
Q
w
LU
C9
I
7 14 21
JANUARY
28
14 21
FEBRUARY
14 21
MARCH
FIGURE 17. RELATIONSHIP BETWEEN RAW AND SETTLED TURBIDITY AS A FUNCTION OF tlME AND MAGNESIUM DOSAGE
MONTGOMERY
-------
TOTAL
to
O
00
Q
-------
time and coagulation pH. An average total hardness of
82 mg/1 as CaCC>3 was obtained during the study. A properly
designed, two stage stabilization basin will produce a
total carbonate hardness of less than 50 mg/1 as
OPERATIONAL CHARACTERISTICS
As the degree of magnesium recovery affects the
economic feasibility of the process, it is extremely im-
portant to account for all losses or gains in magnesium
as previously discussed. The coagulation pH to a large
extent controls the magnesium loss in the finished water.
Figure 19 illustrates the effect of coagulation
pH on magnesium replacement costs for both magnesium
sulfate and magnesium carbonate tri-hydrate. An average
of 4 mg/1 of magnesium as CaCO^ is normally present in the
raw water. As a result of the high magnesium content of the
cake liquor, thirty pounds per day of magnesium, as CaCO3
in the filter cake, are lost each day. As the coagulation
pH increases less magnesium remains in the finished water,
therefore, less make-up is required, decreasing the cost
per million gallons for magnesium expressed as calcium
carbonate .
Figure 20 illustrates the effect of increased
coagulation pH on carbon dioxide and lime costs. Chemical
costs are based on 50 mg/1 of magnesium bicarbonate as cal-
cium carbonate in recycle.
Figure 21 is a summation of Figures 19 and 20 and
represents the total cost for magnesium, carbon dioxide, and
lime as a function of coagulation pH. An optimum pH of 11.2
was found for the situation where magnesium carbonate tri-
hydrate was used as the magnesium source with a total chemical
cost of approximately $19.00 per million gallons. Using
magnesium sulfate, an optimum pH slightly higher than 11.3
58
-------
Mg=4mg/l in raw water
30 LBS/D LOSS IN FILTER CAKE
(Mg as Ca CO3)
15.00
en
vo
$/mg 10.00
5.00
MgSo4 @ $ ,125/LB
(Mg as Ca CO3)
Mg C03 @ $ .07/LB
(Mg as Ca C03)
11.0
11.2
11.4
11.6
pH
FIGURED. MAKE-UP MAGNESIUM COST AS A FUNCTION OF COAGULATIONpH
MONTGOMERY
-------
30.00
$ /mg 20.00
10.00
50 Mg/l Mg C03 RECYCLE
CaO @ $ .01/LB.
C02 @ $ .015/LB.
11.0
11.2
11.4
11.6
11.8
pH
FIGURE 20. LIME AND C02 COSTS AS A FUNCTION OF COAGULATION pH
MONTGOMERY
-------
40.00
50 mg/l Mg C03 RECYCLE
CaO @ $ .01/LB.
C02 <ง> $ .015/LB.
30.00
20.00
10.00
11.0
11.1
11.2
11.3
PH
11.4
11.5
11.6
FIGURE 21. LIME, CO2, AND MAGNESIUM TOTAL COST AS A FUNCTION OF COAGULATION pH
MONTGOMERY
-------
is found with a chemical cost slightly higher than $25.00 per
million gallons.
If dolomitic lime is used as a source of magnesium,
Figure 22 can be used to calculate chemical costs. The only
restraint on coagulation pH in this case is to keep the mag-
nesium content in the finished water below some maximum level
for hardness consideration; generally requiring the coagulation
pH to be kept above 11.0 which would result in a chemical cost
of only $10.00 per million gallons.
The results would indicate that the cost estimates
published in the earlier papers were conservative. The pre-
dicted cost for Montgomery's water of $18.23 was based on a
purchase price for carbon dioxide of $20/ton rather than the
$30/ton now being paid. Table 17 illustrates the average raw
water quality and alum chemical dosages utilized during the
study period.
FILTRATION OF STABILIZED WATERS
Filtered water turbidity was recorded on one of
the four filters treating alum processed water and three of
the four magnesium filters. Filters are normally backwashed
after 100 hours of operation or 7 feet of head-loss, which-
ever comes first.
The months of February and March were selected
as representative of normal operation and the records in-
dicated that the alum filter had an average filter run
of 82.2 hours and an average head loss of 6.4 feet at the
time of washing. During this same time period the magnesium
filters averaged 97.8 hours with a head loss of only 3.3 ft.
The filter capped with anthracite processing the magnesium
treated water averaged over 100 hours filter run with only
1.8 ft. of head loss between washing. When comparing the
sand filter processing magnesium treated waters with the
62
-------
0 )
15.00
$/mg
10.00
5:00
20.00
50Mg/l MgC03 RECYCLE
CAO @ $ .01 / LB.
MgC03
11.0
i ; ;
11.2
11.3
pH
114
115
11.6
FIGURE 22. LIME AND MAGEIMSIUM COSTS AS A FUNCTION OF COAGULATION pH
MONTGOMERY
-------
TABLE 17. RAW WATER ANALYSES AND ALUM DOSAGES,
MONTGOMERY, ALABAMA
Date Total
Alk .
(As CaCOO
1/15
1/22
1/29
2/5 -
2/12
2/19
2/26
3/5 -
3/12
3/19
3/26
4/2 -
4/9 -
4/16
4/23
4/30
- 21
- 28
- 2/4
2/11
- 2/18
- 2/25
- 3/4
3/11
- 3/18
- 3/25
- 4/1
4/8
4/15
- 4/22
- 4/29
- 5/6
AVERAGE
12.1
13.0
12.5
12.7
13.8
12.4
11.8
13.8
15.2
13.5
14.0
16.0
13.0
12.8
14.6
12.3
13.3
Total
Hardness
(As CaCO-^)
11.9
12.7
12.5
13.2
15.4
12.4
11.4
15.0
20.5
15.1
15.8
13.5
13.2
14.4
13.8
14.3
14.1
Turbidity
(FTU)
23.4
37.7
46.5
32.8
38.5
28.5
24.7
31.1
66.4
29.1
50.5
45.7
32.5
25.3
54.3
25.1
37.0
Alum Post & Pre-lime
Dosage Dosage
(mg/1) (mg/1)
16.5
31.4
23.8
32.3
35.0
29.1
20.4
23.9
50.8
45.1
47.3
45.0
38.3
35.8
35.6
31.2
17.6
18.4
18.0
27.0
21.2
17.1
13.2
15.9
21.2
22.6
14.3
19.7
19.1
17.8
19.5
18.84
64
-------
anthracite capped filter there is no noticeable difference
in filtered water turbidities.
During this time period, an average of 7 FTU
(Formizin Turbidity Units) of calcium carbonate turbidity
were being placed on the filters. Ideally precipitation
will be normal with the better carbon dioxide addition.
Based on the experience in Montgomery and the experience of
hundreds of softening plants, problems with shortened filter
runs are not expected.
Filtered turbidities were generally lower on the
magnesium processed water, however, as with the alum process,
coagulation efficiency generally determines the filter
efficiency.
SOLIDS HANDLING
The design information provided by the laboratory
and pilot scaled studies accurately predict full scale per-
formance. The thickener underflow solids ranged from 30% to
45% depending upon the ratio of calcium carbonate to clay in
the sludge. Vacuum filter rates ranged from 3 to 20 Ibs/sq.ft./hr.
Several daily vacuum filter operational data sheets are included
as part of the Appendices. Table 18 summarizes the results of
the vacuum filter operation.
In freezing weather the vacuum filter could not
be operated due to freezing of the vacuum filtrate. The
filter rates increased with thickener underflow concentration
with an average rate of 4.4 Ibs/sq.ft./hr. at 40% solids con-
centration. Due to the reduced operating time and lower than
expected filter rates an average of only 375 Ibs/day of dry
solids dewatered. The remaining 4,894 Ibs was recycled along
with the magnesium bicarbonate and stored in the settling
basin increasing the percentage of CaC03 in the sludge. The
percentage of magnesium hydroxide in the sludge was initially
65
-------
TABLE 18. VACUUM FILTER DATA,
MONTGOMERY, ALABAMA
Date
1/15
1/22
1/29
2/5
2/12
2/19
2/26
3/5
3/12
3/19
3/26
4/2
4/9
- 1/21
- 1/28
- 2/4
- 2/11
- 2/18
- 2/25
- 3/4
- 3/11
- 3/18
- 3/25
- 4/1
- 4/8
- 4/15
Bed
Solids
(%)
29.8
25.8
20.4
22.9
32.0
41.3
48.8
39.3
38.3
34.1
36.2
37.3
40.2
Vacuum Filter
Rate Hrs/day
(Ib/ft2/hr)
2.28
2.69
2.17
2.25
2.72
3.69
8.77
7.42
5.69
3.34
4.94
5.36
5.28
2.7
2.0
1.0
3.0
1.7
3.3
2.2
4.3
4.2
2.9
4.2
3.92
3.3
Ib/day
Dewatered
166
145
59
182
125
330
521
861
645
261
560
567
470
Carbonator feed sludge went from 4.0% solids to 20.0%
solids maintaining the same 17,000 mg/1 alkalinity.
42% as CaCO3 reducing to 8.5% near the end of the study. The
increase of calcium carbonate and turbidity within the system
could be expected to increase the magnesium coagulant require-
ment.
A series of experiments were performed to evaluate
the dewatering characteristics of the carbonated, thickened
sludge on sand drying beds. Four beds, 4 ft X 4 ft each with
six inches of .5 mm sand on top of three inches of gravel with
undrain were constructed. Solids concentrations in excess of
50% were typically found with a drying time of two days to one
week required dependent upon climatic conditions. Assuming a
one week drying time, it was found that 3 Ibs of dry solids
66
-------
could be dewatered each week per square foot of filter area.
The dried cake was easily handled and could be removed readily
by front end loader.
CORROSION STUDIES
A Magma Model 8001 Corrosometer was used to compare
relative corrosion rates for the alum and magnesium treated
waters. Various metal probes are available which change in
resistance as corrosion proceeds. The instrument was used to
measure this change in resistance each day. A -tank was con-
structed with two compartments open to the atmosphere. Fil-
tered magnesium and alum treated waters were fed during the
study with the results illustrated in Figure 23. During this
study period, the alum treated waters had an average pH of
8.9 and carbonate hardness of 43 mg/1. The magnesium treated
water had a carbonate hardness of 75 mg/1 and pH of 8.6. The
corrosion rate for the alum treated water was more than double
that of the magnesium treated water. Although the pH of the
alum treated water was adjusted to a pH in excess of the pH's
of calcium carbonate, little corrosion protection was provided
due to the low level of calcium and carbonate alkalinity present
in Montgomery's water.
COMPARISON WITH ALUM PROCESS
Table 19 summarizes the comparison between the alum
and magnesium for treatment of the Montgomery water.
PROCESS ECONOMICS AND ENERGY CONSIDERATIONS
Economics
Considering process economics, one must include
chemical costs, capital costs, operating and maintenance costs,
67
-------
oo
UJ
DC
UJ
GL
05
240
200
160
12O
80
40
20
1032/W40 Model 8001 Magma Corporation Probe
Alum Total Hardness 43mg/l
pH 8.9
Magnesium Total Hardness 75mg/l
pH 8.6
10
12 14
TIME (DAYS)
16
18
- ;
20
22
-
FIGURE 23. CORROSION RATES FOR ALUM AND MAGNESIUM TREATED WATER
MONTGOMERY
-------
TABLE 19. COMPARISON OF THE MAGNESIUM AND ALUM TREATMENT PROCESSES AT MONTGOMERY
Parameter
Magnesium
Alum
en
Chemical Dosages &
Coagulation pH
Floe Characteristics
Settling Characteristics
Sludge Characteristics
Filtration Characteristics
Finished Water
Characteristics
875 #/M.G. CaO, 800 #/M.G. C02, and
100 #/M.G. of MgS04/ pH 11.2, highly
buffered
Precipitation products, dense, granular
Form rapidly, and not as kinetically
dependent upon water temperature.
Rapid, increased clarifier loading rates,
between lower rate for alum and high
rate for softening plant. High pH
disinfects.
Carbonated sludge thickens to 40% to
50% solids. Approximately 1000 #/M.G.
produced but all splids are dewatered
as an integral part of the process.
All sludge water recovered.
Generally lower filtered water turbidity
calcium carbonate loading will not
shorten filter runs.
Slightly increased hardness and
alkalinity; 40 - 50 mg/1 as CaCO,,
allows pH adjustment for corrosion
control.
250 #/M.G. of alum, 208 #/M.G.
of Ca(OH)of pH from 6.0 - 6.4
poorly buffered.
Hydrolysis products, flocculant
much larger in size, form
slowly with gentle mixing much
slower at colder temperatures.
Generally less than .75
gal/sq. ft./min. loading rate,
sensitive to velocity gradients
in settling basin
Gelatinous sludge normally less
1% solids which can be thick-
ened only to about 6% solids,
approximatley 400 I/M.G.
Filter runs dependent upon
amount of floe carryover.
Very low alkalinity and hard-
ness, generally more red water,
corrosion problems.
-------
TABLE 19. COMPARISON OF THE MAGNESIUM AND ALUM TREATMENT PROCESSES AT MONTGOMERY
Parameters Magnesium Alum
Chemical & Less favorable.for low alkalinity Lower Chemical cost and less
Operations waters increased chemical cost operating and maintenance
Economics unless C02 source becomes available expense when alum sludge is
or domonitic lime proces successful. not treated for disposal.
^ Dependent upon water
conditions
2 Assuming more efficient
first stage carbonation
-------
as well as the various treatment considerations which in-
cludes sludge treatment in many cases.
Based on the previous discussions, a chemical cost
of $13/million gallons is a reasonable estimate for the Mag-
nesium Process. During the project period, an average alum
dosage of 31.2 mg/1 and lime dosage of 18.8 mg/1 resulted
in a chemical cost of $7.96/million gallons.
In order to convert the Montgomery plant to the
magnesium process it is estimated that a capital cost of
$300,000 would be required. These costs are summarized in
Table 20. Amortizing over thirty years at 6% interest would
result in an annual cost of $21,586 or $2.96/million gallons
of water treated (assuming 20 MGD production). Based on the
operating experience during the study period, no additional
labor cost would be expected.
The calcium carbonate-turbidity sludge produced
serves as an excellent soil stabilizer. At one plant in
south Florida, calcium carbonate sludges are sold to cattle
farmers for $1.50/ton, picked up at, the plant site by the
purchaser. Considerable calcium carbonate is sold for this
purpose in Alabama. For this reason, it can be safely
assumed that the dewatered sludge can be cleaned from the
sand drying beds and disposed of at little or no cost in
the immediate area surrounding the water plant.
The additional costs for the application of the
magnesium process at Montgomery can be summarized as:
Additional Chemical Cost $/MG $/yr
$13.00-$7.90 $5.10 $37,230
Capital Cost
$300,000 @ 6% for 30 yrs. $2.96 $21,586
71
-------
TABLE 20. ESTIMATION OF CAPITAL COST FOR
MONTGOMERY'S PLANT CONVERSION
Cost ($)
Stabilization of Settled Water
20 minutes contact chamber 50,000
Instrumentation & Controls 15,000
Mixing Equipment 2.0,000
Sludge Thickening
20' diameter thickener 50,000
Yard piping, sludge pumping, & control 30,000
ป
Sludge Carbonation
Carbonation cells 25,000
Instrumentation & Control 10,000
Recycle of Magnesium Bicarbonate
Recycle storage tanks, pump & control 20,000
Sludge Drying Beds
20,000 sq. ft. @ $2.50/sq.ft. 50,000
Filtrate recycle & piping 15,000
$275,000
Engineering 25,000
TOTAL $300,000
72
-------
Maintenance
2% of Capital Cost $0.82 $ 5,986
Electrical Cost
60 HP 8 $0.01/KWH $0.055 $ 405
$8.94 $65,207
OR
$65,207 per year
Allocating these costs to the dry solids produced
with the alum process would represent a cost of $34.00/ton
for dewatering and disposal. This is significantly lower
than would be expected with alternative sludge treatment
processes.
s
Energy Considerations
Approximately 1500 Hp are required to treat and
distribute 20 MGD of water in Montgomery. The additional
horsepower requirements, 60 Hp, will only add approximately
4% to the existing plant power requirements.
MELBOURNE FULL SCALE RESULTS
As was the case in Montgomery, the magnesium pro-
cess has been found to compare favorably with the presently
used alum process in both overall operation and water quality
produced. Figure 24 illustrates the relationship between
raw water color and treated water color as a function of
73
-------
RAW
240'
220- -44
200 - 40
180- '36
160- 32
140- -28
120--24
100- .20
80- -16
60- -12
40- -8
20- -4
FILTERED
48
(WEEKLY AVERAGES)
FILTERED WATER
14 21 28
SEPTEMBER
14 21 28 7
OCTOBER
14 21 28 7 14 21 28
NOVEMBER DECEMBER
r 200
(I)
O
Q
100 i ฃ
tu ฃ.
z
C9
FIGURE 24. RAW WATER COLOR AND TREATED WATER COLOR AS A FUNCTION OF TIME AND MAGNESIUM DOSAGE
-------
time and magnesium dosage. It has been found that the most
economical treatment at Melbourne occurs when the color
levels are reduced by coagulation to 15 - 20 Pt.-Co. units
and chlorine was used to bleach the final color to less than
5 units. It is interesting to note that the treatment ef-
ficiency improved after several months of operation even at
lower chemical dosages, obviously the result of increased
operator proficiency. The organic color level in the raw
water did not decrease in the late Fall as would have been
predicted from past experience.
As discussed previously, the degree of magnesium
recovery somewhat determines the economic feasibility of
the process. It is extremely important to account for all
losses or gains of magnesium. The losses of magnesium occur
in two areas - the magnesium content in the finished water
and the magnesium lost in the moisture of the filter cake
produced. Sources of magnesium include magnesium present in
the raw water as well as any magnesium source fed in the
process. Figure 25 illustrates the magnesium balance for
Melbourne. The high moisture content in the filter cake
resulted in the equivalent loss of 12 mg/1 of magnesium
as calcium carbonate in the raw water. The finished
water produced contained an average of 6 mg/1. An average
of 11.5 mg/1 of magnesium was found in Melbourne's raw
water during the study period. It is probable with proper
filter cake washing the magnesium loss in the dewatered
sludge can be reduced.
During the course of the study a large amount
of data has been collected. Routine data sheets are in-
cluded as Item 3 in the Appendix and show the type and
quantity of data collected each day by the water plant
operators. In addition, a summary of daily average results
are included.
75
-------
24.0
20.0
16.0
12mg/ILOSS
IN FILTER CAKE
(SINK)
(SOURCE)
'"FEEDJNG iemgTTMg so4
(AS CaC03)
(SOURCE),
|"~' '- |
FEEDING 18mg/l
MgSO
12.0 -
8.0
4.0
RAW WATER (SOURCE)
14 21
SEPTEMBER
FINISHED WATER (SINK)
(INCLUDE Mg(OH)2 FLOG CARRY-OVER)
J-U
(WEEKLY AVERAGES)
28
14 21
OCTOBER
28
14 21
NOVEMBER
28
14 21 28
DECEMBER
a
11.8
--11.3 ฃ
4- 11.4 J
-- 11.3 ง
11.2 O
FIGURE 25. MAGNESIUM SINKS AND SOURCES AS A FUNCTION OF TIME
MELBOURNE
-------
Study of "Color Balance"
One of the most important findings of the Mel-
bourne study is shown in Figure 26. If color release on
sludge carbonation was to prove a problem, the ratio of
organic color to magnesium concentration in the recycled
liquor should have increased with the time that the system
is in operation. This was not the case, however, as the ratio
tended to decrease. This was probably due in part to the
feed of make-up magnesium sulfate as indicated on the graph.
Chlorine Demand Studies
A series of chlorine demand studies were performed
at the Melbourne water plant. These studies were conducted to
determine the effect of free chlorine residual on color re-
duction as well as to determine the chlorine demand for both
the alum and magnesium treated waters. Table 21 illustrates
typical results from one of these tests.
Studies of Carbonated Sludge Dewatering and Thickening
Sludge dewatering studies were conducted on the
carbonated sludge thickener underflow the week of October 1.
Results of leaf filter testing are shown as Table 22. Re-
sults of full scale vacuum filter operation are shown as
Table 23. A full scale thickening study was made during the
period December 20 through January 6. The results are shown
in Table 24. Excellent agreement between leaf filter and full
scale operation was found/ as was the case in Montgomery.
Taste and Odor Studies
Considerable effort was expended in evaluating the
77
-------
1.40 i
1.20 -
1.00 -
00
.80 -
COLOR/MAGNESIUM
RATIO
.60 -
BEGIN MgS04
FEED AT 16
mg/l AS
CaC03
.40 -
.20 -
(WEEKLY AVERAGES)
MgS04 FEED
AT 18 mg/l
14 21 28
SEPTEMBER
14 21 28
OCTOBER
14 21 28
NOVEMBER
14 21 28
DECEMBER
300
RAW WATER COLOR
(Pt-Co>
200
- 100
FIGURE 26. COLOR/MAGNESIUM RATIO AS A FUNCTION OF TIME
MELBOURNE
-------
TABLE 21. CHLORINE DEMAND TEST
(10-5-73)
Magnesium Treated Water
Free Chlorine at
Indicated Time
ppm of Chlorine Added
(Minutes)
15
30
60
120
0
0
0
0
2
.15
.15
.15
.10
0
0
0
0
3
.25
.15
.15
.15
4
1.
0.
0.
0.
00
35
35
15
1
0
0
0
5
.50
.75
.50
.25
1
1
0
0
6
.50
.50
.50
.25
7
1.50
1.50
1.00
0.45
Initial color 25; Final color 7 at 7 ppm Chlorine dosage
Alum Treated Water
Free Chlorine at
Indicated Time
(Minutes)
15
30
60
2
0.15
0.15
0.10
ppm of
3
0.35
0.15
0.15
Chlorine
4
0.50
0.30
0.15
Added
5 6
1.00 2.50
1.00 2.00
0.40 0.50
7
2.50
2.00
1.00
120 0.10 0.15 0.15 0.15 0.20 0.50
Initial color 10; Final color 5 at 7 ppm Chlorine dosage
79
-------
TABLE 22. LEAF FILTER TEST RESULTS - MELBOURNE
Form Time Dry Time Bed Filter Rate Cake Moisture
(sec) (sec) (% solids) (Ib/ft^/hr) (%)
30
60
90
120
30
60
90
120
TABLE 23.
Form Time
(sec)
171
234
260
342
171
234
260
342
60
90
120
180
60
90
120
180
FULL SCALE
Dry Time
(sec)
338
278
251
170
338
278
251
170
41.8
41.6
41.7
41.7
15.0
14.7
13.1
12.6
43
38
30
26
17
14
11
9
VACUUM FILTER RESULTS -
Bed
(% solids)
41.9
41.9
41.9
41.9
28.9
28.9
28.9
28.9
Filter Rate
(Ib/ft2/hr)
20.0
17.6
19.7
19.7
12.6
11.7
12.4
13.5
45
45
46
44
44
46
45
45
MELBOURNE
Cake Moisture
(%)
45
45
45
45
43
44
45
46
80
-------
TABLE 24. MELBOURNE SLUDGE THICKENING STUDY
Date
Thickener Feed
Thickener Underflow
2/20
2/21
2/22
2/23
2/24
2/24
2/25
2/26
2/27
2/28
2/29
2/30
2/31
3/1
3/2
3/3
3/4
3/5
3/6
GPM
5.0
5.0
7.5
7.5
10.0
10.0
10.0
5.0
5.0
7.5
7.5
10
10
5
5
7.5
7.5
10.0
10.0
% Solids
9.33
10.55
9.19
10.29
9.38
9.18
10.14
9.39
10.35
10.34
8.82
9.98
7.96
8.55
10.04
8.86
9.70
11.09
7.50
Ib/day
5987
6580
8599
9905
12,039
11,779
13,014
6019
6645
9953
8490
12,578
10,216
5486
4671
8529
9337
14,238
9626
GPM
1
1
1
1
1
1
1
1.5
1.5
1.5
1.5
1.5
1.5
2.0
2.0
2.0
2.0
2.0
2.0
% Solids
29.22
30.20
27.30
21.58
24.56
24.67
25.15
25.85
25.48
25.50
24.90
25.76
24.20
20.47
20.28
19.07
20.04
20.13
18.78
Ib/day
4205
3929
3900
3028
3535
3492
3620
5582
5502
5505
5376
5561
5224
5696
5643
5306
5624
5601
5226
lb/ft2
/day
53.9
50.0
49.0
38.6
45.03
44.49
46.12
71.1
70.1
70.1
68.5
70.8
66.6
72.58
71.8
67.0
71.6
71.4
66.6
81
-------
use of potassium permanganate for taste and odor removal. It
was found that at the high coagulation pH of 11.3 extremely
rapid reactions occurred between the potassium permanganate
and the organics present in the water. As the permanganate
would not selectively oxidize the compounds producing odor
and taste, very large dosages were required to effectively
remove taste and odor. The potassium permanganate could
be fed at the raw water intake for reaction with the taste
and odor components prior to reaching the plant and sub-
sequent pH elevation in rapid mixing. However, as low
carbon dosages were adequately preventing taste and odor
problems, no action was taken to further investigate the
use of potassium permanganate.
The elevated pH had little effect on carbon ad-
sorption of taste and odor. Essentially the same carbon
dosages were used to maintain similar quality treated waters
on both the alum and magnesium treated processes.
Studies of "Organics" Present in the Raw Water
Samples of raw water, finished water treated with
alum and with magnesium carbonate were collected over a
twenty-four hour period, separately composited and shipped
by Air Express to the Athens, Georgia laboratory of the
Environmental Protection Agency for analysis by gas chroma-
tography. In addition, organics in each of the three waters
were continuously removed over a two day period in special
filters provided by the E.P.A. Cincinnati laboratory and
shipped to that laboratory for analysis.
Two sets of samples were analyzed for total organic
carbon. The raw water was found to have 37 mg/1 on September
12 and 28 mg/1 on October 9. The alum treated water ranged
in TOG from 10 mg/1 on October 9 to 18 mg/1 on September 12.
82
-------
One sample taken October 9 found the magnesium treated water
to have 12 mg/1 of TOG.
The results of the studies related to determining
and quantifying the organics present in Melbourne's raw
and treated waters were somewhat indefinite. E.P.A. has
developed a procedure for extracting the organic carbon onto
carbon columns in a specified manner. These carbon filters
were than mailed to E.P.A. for extraction of the organics
from the carbon with both alcohol and chloroform. The
alcohol extract is called CAE; the chloroform extract is
called CCE. The CCE value for the raw water ranged from 1.1
to 1.7. The magnesium treated water ranged from 1.0 to 1.6
and the alum treated water ranged from 2.4 to 2.5. The CAE
values for the raw water were 3.9, with magnesium treated water
4.2 and alum treated water 11.3. All of these values are ex-
tremely high. It is interesting to note that neither the
alum nor the magnesium process removed these organics, al-
though color removal was taking place. This is also upheld
in the TOC analysis reported earlier. While the color was
essentially completely removed, only 50% of the TOC was re-
moved as a result of the treatment process.
The increase in carbon as a result of the alum
process could possibly be explained by the fact that during
periods when the filter head loss is high alum floe is
actually pulled through the filter which contained high
concentrations of organic material absorbed on the floe.
These results would indicate that neither process is effective
in completely removing the organics adsorbed on these columns.
E.P.A. has completed extensive analysis for heavy
metals in both the alum and the magnesium treated waters.
The magnesium treated water showed metals concentrations of
50% or less, of those found in the alum treated water.
There were no significant concentrations of metals found in
83
-------
either, however. As an example, copper was 17 parts per
billion in the alum treated water and 9 parts per billion
in the magnesium treated water. Zinc was 190 parts per
billion in the alum treated water and 76 parts per billion
in the magnesium treated water. These results are included
in the Appendices as Appendix D, together with correspondence
with the E.P.A. laboratories concerning the organics studies.
Pilot Calcination Results
Near the end of the study, several drums of de-
watered, but unwashed, sludge were shipped to the BSP Division
of Envirotech in Brisbane, California for a continuous cal-
cination study in a 30" diameter multiple hearth furnace.
The results of this study, as indicated below, were some-
what inconc lus i ve.
The most important aspect of this study was the
relatively poor quality lime produced. Only quick-lime con-
taining 63.2% calcium oxide content was produced. This can
be explained for the following reasons:
1) The nature of the multiple hearth furnace is
such that temperatures in excess of 1750ฐF are
damaging to the mechanical components. In the cal-
cining zone of a rotary kiln temperatures in excess
of 2000ฐF are usually employed. Due to the geometry
of the pilot furnace, severe short circuiting be-
tween hearths was evident. The increased tem-
peratures would probably have increased the cal-
cium carbonate conversion efficiency and produced
a more reactive product.
2) More important, however, relatively poor lime
was used initially in the project. So poor that one
84
-------
shipment was rejected. This lime has approximately
15% inerts and would result in build-up of the in-
ert fraction of the sludge tested. In full scale
operation, it would be extremely important to begin
with the highest quality lime possible.
3) The sludge studied was the result of many
hundreds of cycles of coagulant reuse. It is
possible that some build-up of inerts from the
raw water is possible after this period of operations,
Periodic wasting of lime may be required. However,
this will not be more frequent than the six month
period of this study. The wasted lime would have
considerable value as a soil pH conditioner.
Lime recalcination at Melbourne would appear both
economically and technically feasible. Considerable attention
should be directed to determining which type of hearth furnace
should be used: rotary kiln, multiple hearth furnace or fluo-
solids reactor. Each offers advantageous features and a
thorough evaluation is required.
Design Table Summary
Table 25 summarizes the design criteria determined
from both the Montgomery and Melbourne studies.
In the design of the sludge carbonation device,
using furnace exhaust gas as a carbon dioxide source may
result in a foaming problem. The 80% air content in the
exhaust gas may cause foam due to the surface properties
of the organic color in the recovered magnesium bicarbonate
liquor. This foam can be collected and drained to the tail
85
-------
TABLE 25. DESIGN TABLE SUMMARY
Unit
Design Parameters
Comments
Rapid Mix
Flocculation
Clarifier
Filtration
Settled Water
Carbonation
Sludge Carbonation
Purchased 100% CO2
Kiln Gas 18% CO2
Sludge Thickening
Sludge Dewatering
10 - 30 seconds
15-30 minutes
1.0 gal/sq.ft./
min.
2.0 - 4.0 gal./
sq.ft./min.
10 - 30 minutes
15 minutes
60 minutes
40 - 50 Ibs/
sq.ft./day
25 - 35 Ibs/
sq.ft/day
Short rapid mix
appears to be
desirable in color
removal applications.
Floe forms rapidly.
However, contact
time increases color
adsorption.
The use of polymers
prevents excessive
Mg (OH)2 floe carry-
over.
Filter rates up to
4.0 gal/sq.ft./min.
were evaluated in
Montgomery. Increased
rates improved per-
formance normally.
Two stage, separated
by time, shown as
design parameters.
Foaming problems
solved by collection
in launder drained to
tail box.
Increase in loading
rate will produce
solids underflow less
than 30%.
Lower rate is for
feed solids less
than 30%.
86
-------
box with a launder on one side of the unit.
Miscellaneous Studies
Calcium carbonate precipitation within the filter
media was not found to be a problem as long as the pH of the
stabilized water was kept below 8.6 to 8.8. The anthracite
filter seemed to be less affected by calcium carbonate pre-
cipitation.
The length of filter operation between backwashing
affects the net water produced. For the period October 1
through November 15, the alum process sand filter averaged
37.3 hours between backwashing and the anthracite-capped
(3") filter averaged 40.5 hours. During the same time period,
the magnesium process sand filter averaged 37.0 hours and
the anthracite-capped filter averaged 45.5 hours between
washings. Later in the Fall it was reported that the alum
filters were being washed considerably more frequently due to
"air binding" while the magnesium filters maintained the
same total hours of operation. The granular calcium car-
bonate turbidity produced in the stabilization of the
clarified magnesium treated water, while considerable
in quantity, does not have the filter-binding properties
of alum floe carryover.
During the course of the study an excess of both
lime and C02 was used. Near 100% transfer efficiency is
possible with pure CC>2 in a properly designed carbonation
basin. Due to the short retention time and shallow water
depth in the effluent clarifier launders, efficiencies of
50% or less were achieved.
Lime feed was not maintained to provide a uniform
coagulation pH. A reduction of approximately 20% in lime re-
quirements would be predicted from the data sheets for an
87
-------
average CaO feed of 275 mg/1. This can be accomplished
primarily through the use of properly designed lime handling
and feeding equipment as well as automatic pH control.
ECONOMICS AND ENERGY CONSIDERATIONS
Economics
The chemical costs will be evaluated both with and
without lime recalcination and the purchase of lime and car-
bon dioxide.
Looking first at the costs associated with lime
recalcination and the purchase of lime and carbon dioxide,
the recovery of 15 tons/day of lime can be estimated as:
Capital Costs $/year $/ton of CaO
$900,000 for 25 years 6% 69,595 12.71
(25 ton/day kiln)
Maintenance
2% of Capital Cost 18,000 3.30
Power (Gas & Electricity)
$11.00 per ton CaO 60,225 11.00
Operation
Four (4) operators @ $8,000/yr 32,000
1/2 Maintenance @ $8,000/yr 4,000
1/4 Management @ $10,000/yr 2,500
38,500 7.03
TOTAL (Based on an average production
of 15 tons/day) $186,320 $34.04
88
-------
When producing 10 tons per day, as in the Winter
period, the costs will climb to $45.54 per ton. As lime re-
quirements increase due to increases in water production, the
cost per ton will decrease. Producing 25 tons per day of CaO
will result in a cost of $24.82 per ton of lime.
In calculating the chemical costs for water treatment,
the following costs are assumed:
Lime - Delivered at $30/ton CaO
CO2 - Delivered at $30/ton CaO
Lime - Calcined at $39.79/ton CaO
(Average production at 12.5 tons/day)
Magnesium Sulfate - at $240/ton magnesium as Calcium
carbonate (magnesium carbonate
should be available at $100/ton
within 12 months)
The average chemical dosages on an annual basis are:
CaO - 225 mg/1
CO2 - 155 mg/1
Magnesium - 5 mg/1
With lime recovery, the cost per million gallons
would be:
CaO - 225 X 8.33 X $0.019 = 37.29
C02 - - 0 -
Magnesium 5 X 8.33 X $0.12 = 5.00
TOTAL $42.29
The cost not recovering lime would be:
CaO - 225 X 8.33 X $0.015 = 28.11
C02 - 155 X 8.33 X $0.015 = 19.37
Magnesium 5 X 8.33 X $0.12 = 5.00
TOTAL $52.48
89
-------
It is interesting to note that chemical costs,
with recalcination, are only slightly affected by increases
in chemical dosages. This would allow the operation a large
safety factor in treatment at a very modest cost.
On an. annual cost basis, the cost for coagulation
and stabilization chemicals would be:
With recalcination - $154,358
Purchase Lime + CO2 - $191,552
Alum and Lime - $94,170
This is based on an average water production of 10 MGD.
The capital costs required to modify both the North
and South Melbourne plants to use the magnesium process have
been estimated to be $612,900.15 This cost is only for the
additional units required to include the magnesium process
and is included for comparable purposes only. The cost does
not include plant modification required to increase the cap-
acity to 22 MGD. Amortized over twenty-five years at 6% interest
would require $47,394 per year for capital recovery. Main-
tenance at 2% of capital cost would amount to $12,258 per
year. Operation would not require any additional personnel
with recalcination, as the furnace operators would also be
responsible for sludge dewatering. Without recalcination,
a cost of $16,000 has been estimated for operation of the
vacuum filter and sludge thickening.
To summarize the total costs for water treatment
utilizing the magnesium process:
90
-------
Lime Recalcination $/year
Chemical Costs 154,358
Capital Amortization 47,394
Maintenance 12,258
Electrical Power 3,000
TOTAL COST $217,010
Purchase Lime and
Chemical Costs 191,552
Capital Amortization 47,394
Maintenance 12,258
Operation 16,000
Electrical 3,000
TOTAL COST $270,204
Lime recalcination will produce some excess lime,
amounting to some 2 to 4 tons per day during the hard water
season which should have a value of approximately $20,000
per year. No credit is given in this economic comparison.
s
The filter cake, in the case where lime values are not re-
covered, is composed primarily of calcium carbonate. It
could be worth approximately $1.50 per ton to local cattle
ranchers as another water treatment plant in the area has
made such an arrangement. The ranchers pick up the filter
cake at the plant in their trucks.
In order to compare the magnesium process with the
present alum process, sludge dewatering using a filter press
is included. In addition, as increased clarifier size is re-
quired for the alum process but not for the magnesium process,
these additional costs are noted as plant additions.
The capital cost for the filter press and appur-
tenances has been estimated at $1,250,000 ahd the plant
additions at $298,000 for a total capital cost of $1,548,000.
These cost estimates are derived from the Smith and Gillespie
91
-------
Report of 1973. The costs can be summarized as:
$/year $/ton*
Capital Amortization 119,703 54.60
($1,548,000 6 6% for 25 years)
Maintenance @ 2% 30,000 14.13
Operation of Press 20,000 9.13
Power (Press) 5,000 2.28
Chemicals (Press) 32,850 15.00
Sludge Hauling to Suitable 35,000 15.98
Landfill
Present Chemical Cost 94,170
TOTAL COST $337,683 $111.12
*Based on 22 MGD production, 6 tons of dry solids per day.
It should be emphasized that sludge hauling costs
can be expected to increase in the future as haul distances
become longer and hauling costs increase.
Summarizing these costs:
Annual Cost
Magnesium Process
With recalcination $217,010
Purchase lime and CO2 ' $270,204
Alum Process
Including plant improvements $337.683
and sludge pressing
Energy Considerations
Lime recalcination requires considerable on-site
energy, thus, careful consideration is in order. The fol-
lowing facts would appear to apply:
92
-------
A. Commercial quicklime, used in larger tonnage than any
other water treatment chemical, requires the following
energy-consuming operations for its manufacture:
1) Mining of limestone or marble in quarry
2) Transporting to kiln
3) Crushing and grinding before burning
4) Burning in vertical shaft or rotary kilns
5) Bulk shipment (600 miles in Melbourne's case)
6) Unloading and shipment to the water plant.
B. Recalcining calcium carbonate sludge on-site would:
1) Eliminate 1, 2, 3, 5 and 6.
2) The additional heat required to evaporate the
moisture from the filter or centrifuge cake is
only slightly higher than for (4).
3) Produces more than sufficient CO2 in the stack
gas to carbonate the plant's finished water, for
stabilization and sludge carbonation, thus making
an important energy saving.
4) Eliminates the need for hauling dewatered sludge
for ultimate disposal.
This very simplistic approach to evaluating the
energy balance of the two alternatives would weigh heavily
in favor of on-site lime recovery.
93
-------
SECTION VI
REFERENCES
1. Eidsness, F. A. and A. P. Black. Carbonation of
Water Softening Plant Sludge. J.AWWA.
49:1343 (1967).
2. Black, A. P. Split-Treatment Water Softening At
Dayton. J.AWWA. 58:1:97 (January 1966).
3. Black, A. P., B. B. Shuey and P. J. Fleming.
Recovery of Calcium and Magnesium Values From
Lime-Soda Softening Sludges. J.AWWA. 63i(10):616
(October 1971).
4. Thompson, C. G., J. E. Singley and A. P. Black.
Magnesium Carbonate - A Recycled Coagulant.
J.AWWA. 64:(!):!! (January 1972).
5. Thompson, C. G., J. E. Singley and A. P. Black.
Magnesium Carbonate - A Recycled Coagulant,
Part II. J.AWWA. 64:(1):94 (February 1972).
6. Department of Public Utilities (Gainesville, Florida).
Magnesium Carbonate, A Recycled Coagulant For
Water Treatment. Environmental Protection Agency.
Washington, D. C. Publication Number 12120 ESW.
June 1971. 107 p.
7. Sperry, W. A. The Lime Softening Of Water And The
Use Of The Sludge As An Aid Thereto. J.AWWA.
6:215 (June 1919).
8. Hartung, H. O. Experience With Up-Flow Type Basins.
Water & Sewer Works. 1:91 (January 1944).
9. McCauley, R. F. and R. Eliassen. Accelerating Calcium
Carbonate Precipitation in Softening Plants. J.AWWA.
52:106 (May 1955).
10. Tuepker, J. L. and H. O. Hartung. Effect of Accumulated
Lime-Softening Slurry on Magnesium Reduction.
J.AWWA. 52:106 (January 1960).
94
-------
11. Lawrence, R. W. Equilibrium And Kinetics For The
Carbonation of Magnesium Hydroxide Slurries.
Research and Development Progress Report #754.
U. S. Department of Interior. (December 1971).
12. Riehl, M. L., H. H. Weiser and R. T. Rheins. Effect
of Lime Treated Water Upon Survival Of Bacteria.
J.AWWA. 44:466 (May 1952).
13. Chaudhure, Maley and R. S. Engelbrecht. Removal Of
Viruses From Water By Chemical Coagulation And
Flocculation. J.AWWA. 62:563 (September 1970).
14. Flentje, M.E. Calcium And Magnesium Hydrates. J.AWWA.
17:253 (1927).
15. Smith & Gillespie Consulting Engineers, Inc. (Jacksonville,
Florida). Water Treatment Facilities Report, Melbourne,
Florida. (February 1973).
95
-------
SECTION VII
APPENDICES
Page
A. DATA SHEETS TO SHOW TYPICAL RESULTS,
MONTGOMERY, ALABAMA 97
B. VACUUM FILTER TESTS, MONTGOMERY, ALABAMA 117
C. ROUTINE DATA SHEETS,
MELBOURNE, FLORIDA 127
D. SUMMARY OF DAILY AVERAGE RESULTS,
MELBOURNE, FLORIDA 131
E. E.P.A. ANALYSIS FOR HEAVY METALS AND COMMENTS,
MELBOURNE, FLORIDA 133
F. PHOTOGRAPHS OF THE MONTGOMERY AND MELBOURNE
FACILITIES 137
96
-------
APPENDIX A
DATA SHEETS TO SHOW TYPICAL RESULTS,
MONTGOMERY, ALABAMA
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
y/2
oooo
0200
0400
0600
0800
1000
1200
1400
1600
1800
2000
2200
3/3
0000
0200
0400
0600
0800
1000
pjl
0.1
0.15
0.1
0.05
0.2
0.2
0.4
LO.l
LO.l
LO.O
LO.l
0.2
10.3
0.4
10.4
0.35
10.2
10.
RAPID MIX
#1
1 91
TH
116
118
112
107
120
108
80
160
130
96
1,00
100
> 82
82
82
80
88
86
CH
30
30
29
27
24
28
28
34
30
30
30
30
30
78
78
2fi
26
10
MH
86
88
83
80
98
80
52
126
100
66
70
70
52
54
54
54
62
56
R M
A I
P X
1 #2
D **
PH
11.7
11.6!
11.7
11.7
11.55
11.65
11.65
11.05
11.5
11.6
11.5
11.6.5
_llj_7J
11,6
11.54
11.7
11.5
11.65
1 TH-Total Hardness
2 CH-Calcium Hardness
MAGNESIUM FLUME
pH
8.8
8.9
8.9
9.0
9.2
9.0
8.8
8.7
9.0
8.7
8.5
8.0
9.0
9_i5_
9.4
9.1
9.3
8.5
TH
93
99
95
93
96
96
96
110
115
100
105
98
90
JO,
97
85
90
96
CH
87
90
87
86
89
89
90
100
100
95
95
90
87
92
92
81
86
88
ALK
79
81
80
78
82
82
84
88
85
82
84
80
77
76
75
74
80
80
TURB
4.7
5.3
5.0
4.6
6.0
5.8
5.9
6.5
6.0
5.0
4.5
3.8..
4.5.
5,5
4.8
4,6
6.0
5.5
ACID"
TURB
1.7
1.8
1.9
1.7
1.9
1.9
2.0
1.9
2.0
2.0
2.0
1.5
J-.8.
1,8
1.4
1,5
1,1,.
1.9
CARBONATED SLUDGE
pH
7.Sei
7. 55
7.6
7.6
7.6
7.7
7.7
7.75
Not
7.7
7.8
7,8
7,8
7.?.
7,4
7.35
ALK
16000
16600
16100
15900
16100
15600
15600
15400
Taken I
15600
15400
15200
.15JLM-
15100
16700
17200
PUMP
SETTING (gpm)
12
10
10
10
10
10
12
ecau8? Pump
PulJ
MAX-
5. .-..
5
4
6
8
fANK
jEVEI
6.0-
5.5'
5.3'
5.0'
5.01
5.0-
Pull
4.2'
Full
Full
l.fi'
> fi'
1.5'
1.2*
1.0'
2,6'
3.6'
EFFLUENT
FILTER
15
PH
8.8
8.85
8.9
9.0
9.05
8.95
8.9
8.8
8.8
8.8
8.7
fl.4
ft H
9.1
9.1
9.0
9.15
9.0
ALK
71
75
79
80
78
78
76
82
72
72
70
75
74
73
73
71
64
70
C02
SETTING
(cfm)
ttl
IP
10
10
10
10
10
10
10
10
10
10
in
in
in
10
10
10
11
#2
4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.2
'A. n
'#,
'#.
3.JOX
A. 2
1-4
3.6
4,0
3.5
3 MH-Magnesium Hardness
CO
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
3/3
1200
1400
1600
1800
2000
2200
3/4
0000
0200
0400
0600
0800
1000
1200
1400
1600
1800
2000
2200
P"
0.2
0.1
0.1
0.2
0.2
10.2
0.3
L0.4
L0.35
L0.3
L0.25
.0.3
.0.1
10.1
10.2
10.2
10.2
10.3
RAPID MIX
11
1 > >
TH
90
78
79
78
80
85
82
80
82
78
86
80
78
> 76
80
82
84
89
CH
?8
28
28
27
30
30
30
30
30
30
3fi
34
30
32
30
30
32
32
1 *H-Total
2 CH-Calciui
3 MH-Magnes
MH
62
50
51
51
50
55
52
50
52
48
50
46
48
44
50
52
52
57
Hardn
m Bar
ium H
R M
A I
P X
2ซ
pH
11.5
11.7
11.65
11.7
11.65
11.6
11.7
11.75
11.7
11.75
11.7
11.7
11.55
11.7
11.7
11.7
11.7
11.75
MAGNESIUM FLUME
PH
R.R
9.2
9.0
9.0
9.0
9.0
9.0
9.0
9.0
8.9
9.0
9.0
9.0
9.1
9.0
9.0
9.0
8.9
TH
94
98
96
98
LOO
105
102
97
98
90
100
98
100
100
100
100
100
95
CH
8R
92
90
96
92
92
92
94
94
87
90
90
50
92
90
92
90
90
ALK
82
80
82
80
78
78
80
82
82
78
82
80
80
80
78
78
80
80
TURB
5.8
6.2
6.0
5.8
5.0
4.8
5.0
5.5
5.5
5.3
5.1
3.0
3.0
3.8
4.0
4.0
3.8
3.0
ACID
TURB
1.9
1.9
2.0
1.8
1.8
1.8
1.8
1.9
1.7
1.5
1.6
1.5
1.3
1.4
1.8
2.0
2.0
1.0
CARBONATED SLUDGE
PH
7,8?
7,9
7.8
Not
7.8
7T8
7,9
8.0
7.9
8.0
8.1
8.05
8.05
8.1
B.O
8.1
3.0
7.2
ALK
15100
14900
Taken
14500
14400
13500
13300
13500
13000
13000
12700
12200
12000
12000
11500
11000
12200
PUMP
SETTING (qpm)
8
8
All
All
All
All
All
Max.
Max.
Max.
Max.
Max.
Max.
Max.
Max.
Max.
Max.
Max.
TANK
LEVEI
4.5'
6.5'
Full
5,5'
4.8'
4,8'
4.8'
5.2'
5.6'
6.1'
6.6'
6.5'
6.8'
6.81
6.7'
Full
Full
hSi
EFFLUENT
FILTER
#5
PH
8.65
8.8
8,9
8,9
8,9
8.?
8.9
9.0
9.0
8.9
8.9
9.3
8.9
8.85
8.8
8.8
8.8
8.8
ALK
72
70
71
72
74
72
74
78
78
76
70
66
70
74
74
72
72
70
CO 2
SETTING
(cfm)
#1
11
11
11
11
11
11
11
11
11
11
12
12
12
12
12
12
12
12
#2
3.5
3.7
3.7
3.7
3.7.
ฑ.y
A.Q
4.0
4.0
4.0
%
3.8
4.0
4.0
4.0
4.0
4.0
.Q/
/r.4
4.4
ess
dness
ardness
vo
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
3/5
0000
0200
0400
0600
0800
1000
1200
1400
1600
1800
2000
2200
3/8-
0000
0200
0400
0600
0800
1000
RAPID MIX
#1
^ ป. *
Pll
0.4
0.35
0.35
0.35
0.25
9.9
9.95
0.0
0.0
0.0
0.0
.0.0
.0.1
10.15
LO.l
L0.15
LO.l
.0.1
TH~
70
70
70
70
72
118
92
100
101
100
102
100
96
94
104
102
111
110
CH"
12
32
32
34
37
42
40
47
44
48
50
52
32
30
30
28
32
30
MH"
48
38
38
36
35
76
52
53
57
52
50
48
64
64
74
74
79
80
R M
A I
P X
1 #2
D "
PH
11.6*
11.6
11.7
11.7
11.7
11.65
11.7
11.6
11.7
11.7
11.65
11.7
11.8!
11.7
11.4
11.7
11.6!
11.4
MAGNESIUM FLUMK
pH
9.1
8.9
8.9
8.8
8.7
8.8
8.7
9.2
9.1
9.0
9.0
9.0
8.9
9.0
9.0
8.9
8.C
8.(
TH
95
95
95
94
90
90
93
91
93
95
92
94
94
92
88
84
85
86
CH
92
90
90
91
89
91
92
90
91
90
90
90
88
88
86
83
84
84
ALK
78'
80
80
82
76
76
76
74
72
74
75
75
78
78
76
73
73
74
TURB
3.0
3.2
3.3
3.4
3.2
3.5
2.2
3.6
3.0
3.2
3.2
3.2
3.2
3.5
3.8
3.5
3.6
3.4
ACID
TURB
1.4
1.2
1.2
1.4
1.2
1.1
1.1
1.1
1.4
1.1
1.2
1.1
1.2
1.2
1.4
1.2
1.4
1.3
CARBONATED SLUDGE
pH
8,1
7,9
fl.fl
8.1
8.0
7,5
7.35
7.3
7.4
7.4
7.5
7.5
7.5
7.5
7.4!
7.5
7.7
7.6!
ALK
13300
14400
12200
10000
11500
16100
16200
17900
16800
17000
16900
14800
14900
14903
15100
12600
13000
PUMP
SETTING (qpm)
flax
Max
Max
Max
Max
10
10
9.5
9.5
Max
Max
Max
Max
11
9
8
8
8
TANK
LEVEI
Full
Pull
7.01
7.0'
Full
4.0'
2.0'
2.5'
3.0'
3.8'
4.0'
5.5'
5.8'
4.8'
2.8'
4.0'
4.0'
4.0'
EFFLUENT
FILTER
15
pH
9.0
9,0.
8,9
8.8
8.8'
3.8
8.8
9.0
9.1
8.9
8.9
8.9
8.9
8.9
B.9
8.9
8.8
8.7
ALK
70
70
72
72
72
70
70
68
65
68
65
68
68
68
C7
65
64
66
C02
SETTING
(cfm)
#1
12
12
12
12
12
12
12
12
12
12
12
12
12H
12H
.2+
.2+
.2
.2
#2
4.4
4,4..-
4.4
4,4
4T4
4.4
4.4
4.4
4.4
4.4
4.4
4.4
4.0
4.0
4.0
4.0
%,
3.7
o
o
1 TH-Total Hardness
2 CH-Calcium Hardness
3 MH-Magnesium Hardness
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
3
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
3/8
0000
0200
0400
0600
3/13
1600
1800
2000
2200
3/14
0000
0200
0400
0600
0800
1000
1200
i4oe
1600
1800
PH
10.4!
10.35
10.4
Ipt45
8,65
9,8
8.8
8,3
8.9
9.6
9.7
9.75
9.75
9.5
9.9
9.85
9.9
9.8
RAPID MIX
#1
TH~
6?
68
$$
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
3/14
2000
2200
3/15
nnnn
0200
0400
0600
0800
1000
1200
1400
1600
1800
2000
3/16
0000
0200
0400
0600
0800
PH
0.0
0.1
0.2
.8
.9
0.2
L0.25
LO.O
LO.l
LO.O
10.1
10.1
10.1
10.1
10.0
10.0
10.0
10.1
1
2
3
RAPID MIX
#1
i ซ .
TH1
10?
106
80
64
98
78
79
134
126
127
112
IIS
121
118
115
115
130
116
CH*
4ft
50
46
35
50
48
49
54
48
50
56
51
48
50
4R
Sfl
52,
4ft
TH-Total
CH-Calciu
MH-Magne
MH"
54
56
34
29
48
30
30
80
78
77
56
64
73
68
67
77
78 .
68
R M
A I
P X
1 #2
D *^
PH
11.8
11.6
11.7
11.6
11.65
11.7
11.75
11.5
11.7
11.7
11.6
Jl-6
11.6
11.7
11.6
11.7
11.7
11.8
MAGNESIUM FLUME
pH
9,7
9.1
9.2
9.3
9.4
8.6
9.1
9.4
9.0
8.5
8.6
Ji. 8
9.0
*>!
9.0
8.7
8.4
R.7
TH
inn
101
100
99
101
105
105
107
112
119
116
116
118
110
115
170
119
109
CH
99
101
100
97
100
104
104
105
109
116
112
112
114
109
110
IIS
119
109
ALK
R?
82
84
81
83
87
91
90
86
88
81
83
86
80
90
90
95
88
TURB
a A
9.9
9.9
15.0
20
15
20
20
25
20 -,
19
18
18.
20
21
20
18
18
ACID
TURB
2.9
3.0
2.5
3.3
2.5
2.6
2.2
2.0
2.0
2.4
1.8
1.7
1.5
1.5
1,5
1,3
1.4
1.5
CARBONATED SLUDGE
I
PH
7.5
7.5
7.5
7.5
7.5
7.65
7.85
7.8
7.3
7.35
7.5
7.5
7.6
7.7
7,65
7,65
7,65
7.65
ALK
15400
15200
14400
14500
14500
13300
13200
12400
12900
15300
14300
14400
14600
14500
14QOO
14200
14000
14200
PUMP
SETTING (qpm)
10
10
10
10
14
14
14
11
10. ง
10.5
10.5
in
10
10
10
;o
12
12
TANK
LEVEI
6.5'
6.5'
6.5f
6.5'
6.31
6.5'
6.5'
5.9'
4.0'
5.0'
6.0'
s.n-
4.2'
4.51
6.5'
6,5'
5,8'
3.5'
EFFLUENT
FILTER
#5
PH
8.9
9.0
9.2
9.3
9.1
8.85
9.0
9.0
8.9
8.8
8.7
B.7
8.7
8.8
8.9
8.6
8,6
8.7
ALK
64
6J
72
78
75
85
83
84
79
85
81
77
72
80
81
85
?P
91
C02
SETTING
(cfm)
#1
14
14
14
14
14
14
14
14
144
14+
14
14
14
14
14
14
14
14
#2
4.2
4.2
4.2
4.2
4.2
3.3
3.6
3.6
,4 ?
4.2
4iO
4.2
4.2
4.0
4.0
4.0
3.5
3.3
3,6
Hardness
m Hardness
slum Hardness
o
u>
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
3/16
1000
1200
1400
1600
1800
2000
2200
i/Ll
0000
0200
0400
0600
0800
1000
1200
1400
1600
1800
2000
PH
10.05
10.15
10.15
10.1
9.9
10.1
10.1
L0.25
L0.3
L0.3
.0.3
.0.2
10.3
10.2
10.1
10.2
10 11
10.1
RAPID MIX
#1
THX
124
122
118
121
120
122
118
120
100
106
114
94
104
i 110
114
117
1181
126
CH*
46
47
47
51
50
51
54
48
50
50
50
48
56
48
10
4R
52
52
MHJ
78
75
71
70
70
73
64
72
50
56
64
46
48
62
M
64
$6
74
R M
A I
P X
Jซ
pH
11.65
11.7
11.65
11.6
11.5
11.5
11.5
11.6
11.6
11.6
11.6
11.65
11.65
11.6
11.65
11.5
H-5
11.6
MAGNESIUM FLUME
pH
8.7
8.7
8.8
8.8
8.4
8.4
83
7.3
8.5
9.1
9.3
9.6
9.1
8.4
fli?
9,0
9.1
8.9
TH
111
110
111
110
110
112
115
134
124
112
110
97
108
112
IIP
107
1D7
109
CH
111
108
110
107
108
110
114
114
108
108
100
95
108
106
110
lOfi
104
107
ALK
88
85
87
82
95
90
87
90
85
85
88
80
87
88
89
85
81
82
TURB
18
15
15
14
10
10
9
5.8
8.5
14
17
18
17
12
10
9 -
8.5
8.0
ACID
TURB
1.4
1.3
2.2
1.4
1.3
1.7
2.0
1.7
1.9
1.8
1.4
1.5
1.6
1.7
1.5
1.6
2.0
2.0
pH
7.5
7.35
7.55
7.1
7.3
7.25
7.3
7.1
7.1
7.35
7.2
7.7
7.25
7.3
7,3
7,2
7.2
7.25
CARBONATED SLUDGE
ALK
15700
15100
15500
16400
15900
16000
15800
16600
14600
16500
16400
15100
15600
16300
16200
16100
16000
16200
PUMP
SETTING (qpm)
11
15
14
14
14
10
10
9
8
8
8
5.5
5.5
5.5
5.5
6.0
8.0
9.0
TANK
LEVEI
4.5'
3.8'
4.3'
4.5'
4.2'
4.0'
3.5'
3.01
2.0'
2.6'
3.6'
4.5'
4.0'
4.8'
5.2'
4,5'
5.0'
3.0'
EFFLUENT
FILTER
#5
J?H
8.7
8.7
8.6
8.7
8.7
8.7
8.6
8.3
8.5
8.6
8.9
9.2
9.0
8.6
8.6
8.7
8.8
ALK
80
78
79
76
75
77
80
88
88
86
67
78
77
82
80
77
75
C02
SETTING
(cfm)
#1
13
13
13
13
13
13
13
10
10
10
10
10
12
12
12
12
12
12
\2
3.2
3.2
3.2
3.0
J;L
2.7
%>
2.0
2.0
2.0
2.0
2.0
3.5
3ฃ=
2#o
*2I^
%
2.4
1 TH-Total Hardness
2 CH-Calcium Hardness
3 MH-Magnesium Hardness
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
^T/17
2200
38no
0200
3/21
1400
1600
1800
RAPID MIX
#1
^ * *
pH
mite
9.8
10.2
10.1
0.2
.7
0.2
10.3
10.3
10.3
9.9
10.0
10.2
9.9
10.0
9.95
10.0
10.0
1
2
3 1
TH -
Elep
114
120
124
112
106
no
92
> 92
93
97
101
109
116
102
142
134
138
CH*
hant
4?
54
S2
50
40
46
SO
50
5?
47
43
4?
46
40
34
40
4?
IB-Total
CH-Calciu
MH-Magnes
MH~
on S
72
66
72
62
66
64
42
42
41
50
58
67
70
62
108
94
96
R M
A I
P X
1 #2
D *^
PH
trike
11.4
11.6
11.6
11.6
11.6
11.5
11.5
11.6
11.4
11.4
11.6
11.4
11.3
11.15
11.7
11.6
11.5
MAGNESIUM FLUME
pH
Co:
8.2
7.8
8.8
9.4
9.5
9.1
8.6
8.7
8.7
9.0
9.0
8.9
9,fi
9.3
7.8
9,4
9.7
TH
reel
106
106
102
100
99
105
115
115
110
108
106
1.05
130
inn
82
8R
79
CH
ed ^
100
09
98
92
96
99
110
110
106
106
100
98
98
90
81
84
75
ALK
t 223
86,
78
80
74-
75
78
78
88
82
80
75
76
95
78
74
79
70
TURB
0 (Fr
6.3
5.5
5.4
6.7
5
6
5.3
5.5
5.1
5.0
4.8
4.5
5.8
4.9
6.0
6.2
10
ACID
TURB
om 21
2.2
2.4
2.5
2.6
2.2
2.3
2.1
2.0
1.9
1,8
2.0
1.8
2.5
2.5
3.0
2.6
3.0
CARBONATED SLUDGE
PH
30 ti
7.4
7.3
7.3
7.4
7.4
7.3
7.4
7.25
7.2
7.25
7.25
7.35
7.4
7.35
7.5
7.7
7.7
ALK
> 2230)
15900
1600
1600
1600
15600
15200
15400
15600
15100
15700
16200
16400
17600
18500
16900
16200
15100
PUMP
SETTING (qpm)
11
11
11
11
11
11
11
11
10
9
9
8.5
15
14.5
14.5
TANK
LEVEI
3.4'
4.4'
5.0'
4.1'
4.8'
4.0'
6.0'
6.8'
6.5'
4.5'
3.0'
3.0'
2.0'
3.0'
5'
5.5'
5.5'
EFFLUENT
FILTER
#5
PH
8.8
8.4
8.6
8.9
9.1
9.0
8.8
8.7
8.7
8.8
8.9
9.0
9.4
9.4
ALK
80
98
90
62
63
64
62
80
82
77
70
71
65
68
CO 2
SETTING
(cfm)
'41
12
12
12
12
12+
12+
12
12
12
12
12
12
12
12
9
^
.10
tys
^12
#2
2.4
1.9
1.0
1.0
l.O/"
sf.o
%
2.5^
sSl.O
2.0
2.0
s3\3
i*.
3.0
3.0
3.0
1.5
^\0
2.0^
^3.0
Hardness
m Hardness
ium Hardness
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE,
3/21
2000
2200
3/22
0000
0200
0400
0600
0800
1000
1200
1400
1600
1800
2000
2200
0000
0200
0400
0600
', .
PH
10.0
10.0
9,8?
9.1
10.0
10.05
10.0
10.0
10.1
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.1
10.0
1
2 (
3 1
RAPID MIX
#1 ;
TH
140
120
X38
132
130
130
130
12,8
130
127
126
124
134
118
148
140
144
140
CH
44
42
49
38
40
42
46
42
45
41
38
36
42
36
40
44
40
40
MH
.2,6.,..,
78
'ft
94
90
88
84
86
85
86
88
88
92
82
108
96
104
100
R M
A I
P X
PH
11.55
ll.fi
11.5
U,5
11.6
11.6
11.7
11.55
11.6
11.5
1.5
.1.5
.1.5
1.5
1.6
1.6
1.55
1.6
pH
9.3
?,2
8.8
?,Q5
8.5
8.9
9.0
9.15
9.3
9.2
3.8
3.6
3.4
).l
>.3
J.3
9.3
9.3
MAGNESIUM FLUME
TH
81
85
92
90
90
90
81
83
85
83
80
94
84
79
90
90
98
82
CH
,77
81
84
84?
8?
86
78
78
80
78
74
80
81
76
80
78
80
72
ALK
72
77
84
82,
80
82
73
70
72
71
75
76
74
76
60
60
66
70
TURB
11'
10
7,5
7,4
9,0
6.0
5.4
5.5
7.5
9.0
7.5
8.5
8.0
8.3
7.2
14.0
7.3
ACID
TURB
2.5
2.7
1.9
1.7
Ir7
It 6
1.5
1.5
1.6
2.0
2.0
1.5
2.0
1.7
1.5
1.4
2.0
1.4
CARBONATED SLUDGE
pH
7 7
7 "?
7.7
7 ซ
7,7
7.2
7.4
7.7
7.4
7.5
7.5
7.5
7.6
7.55
7.45
7.5
7.5
ALK
i^nn
15600
14700
14900
14600
15200
16300
14300
14700
14400
13900
13800
13600
13200
15000
14500
13800
13200
PUMP
SETTING (cT0nO
V "
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
TANK
LEVEI
i 1ซ
n,
7 n1
6.5'
6.0'
6.2f
6.0'
5,5'
5t4'
5.6'
0.0'
6.0'
5.51
6.5'
6.8'
5.1'
3.8'
4.6'
EFFLUENT
FILTER
ts
pH
8.85
8.9
8.8
8.6
8.6
8.8
8.9
8.5
8.8
8.7
8.6
8.9
9.1
9.0
9.2
9.2
ALK
70
72
72
10
71
70
72
70
69
70
69
71
64
68
64
64
C02
SETTING
(cfm)
#1
,12
12
n
n
13
13
13
13
13
13
13
12+
12
12
12
12
12
12
12
#2
1
A. a
4.0
I.Q/
AJ
'fa
2.9
2,9,
A.5
3.5
3.. 4
JJP'
2.0
2.0
2.0
2.0
2.0
H-Total Hardness
?H-Calcium Hardness
til-Magnesium Hardness
O
cn
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
3/23
0800
1000
1200
1400
1600
1800
2000
2200
5/24
0000
0200
0400
0600
0800
1000
1200
1400
1600
1800
J>H
9.9
9.8
10.0
10.0
0.05
0.1
10.1
10.1
10.1
10.0
LO.O
LO.O
LO.O
LO.O
9.9
LO.O
.0.15
.0.2
RAPID MIX
#1
TH1
130
21 n
140
140
118
140
136
134
130
137
137
136
132
135
135
138
122
126
CH-*
40
4S
42
40
40
40
40
38
36
37
38
35
35
35
40
40
38
36
MHJ
90
165
98
100
78
100
96
96
94
100
99
101
97
100
95
98
84
90
R M
A I
P X
lป
pH
11.6
11.6
11.6
11.6
11.6
11.5
11.55
11.6
11.5
11.5
11.55
11.5
11.55
11.5
11.5
11.55
11.55
11.55
MAGNESIUM FLUME
pH
9.5
9.15
8.8
9.0
9.0
9.0
9.2
9.1
9.0
8.9
8.7
8.8
8.7
8.6
8.7
8.6
8.6
8.7
TH
88
95
93
88
97
94
90
96
95
101
97
99
98
96
95
98
98
90
CH
75
82
82
84
94
88
84
86
84
89
86
85
86
86
85
85
85
85
ALK
72
70
70
68
64
69
63
67
66
66
68
67
62
64
60
64
64
72
TURB
4.0
6.0
6.0
5.5
8
9
9
8
8.5
7.p
5.5
5.7
5.2
5.5
5.0
5.5
5.5
5.7
ACID
TURB
1.5
1.5
1.5
1.0
1.8
1.9
1.9
1.7 ,
1.5
1.5
1.1
1.2
1.5
1.5'
1.0
1.5
1.6
1.6
CARBONATED SLUDGE
pH
7.35
7.4
7.4
7.4
7.6
7.5
7.5
7.45
7.5
7.5
7.4
7.45
7.4
7.4
7.4
7.4
7.4
7.49
ALK
13500
12600
12800
12900
13700
14100
14000
13900
14200
13600
14100
14000
13800
13600
13800
14000
14800
14800
PUMP
SETTING (spm]
15
15
15 I
15
15
15
15
15
15
15
15
15
'
Max
Max
TANK
LEVEI
6.6'
4.5'
'oamy
2.5'
2.1'
1.5'
3.01
3.5'
4.0'
4.5'
5.0'
5.3'
4.8'
4.5
4.0'
4.0'
6.5'
6.6'
EFFLUENT
FILTER
#5
pH
9.2
9.2
9.2
9.2
9.0
8.9
9.1
9.0
9.0
8.85
8.5
8.5
8.6
8.4
8.6
8.6
8.6
8.6
LALK
57
59
59
58
58
62
59
60
62
57
61
60
64
62
65
65
65
67
C02
SETTING
(cfm)
#1
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
#2
2.0
3.0
2.0
2.0
2.0
2.0
2.0
*Xป
2.6
2.7
2.5
2.5
2.5
2.5
2.5
2.5
2.S/'
s/2.0
2.0
1 TH-Total Hardness
2 CH-Calcium .Hardness
3 MH-Magnesium Hardness
H
O
-J
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
6
DATE
3/24
?nnn
2200
/25
0000
0200
0400
0600
0800
1000
1200
1400
1600
1800
2000
2200
J/2b
0000
RAPID MIX
#1
pH
10.2
9.9
9.95
9.9
9.9
9.95
9.9
9.9
LO.l
LO.O
LO.O
10.05
LO.O
LO.O
LO.O
0200 10.0
0400
0600
9.9
10.0
TH*-
124
126
124
122
126
130
130
128
130
120
126
128
128
119
125
132
127
i
CH"
36
32
34
30
32
35
32
30
30
28
28
32
36
34
34
36
34
MH3
iMMB^BMW
88
94
90
92
94
95
98
98
100
92
98
96
92
85
91
96
93
R M
A I
P X
S*2
u
pH
11.5
11.5
11.5
LI. 5
LI. 5
LI. 55
LI. 5
LI. 5
LI. 5
L.55
LI. 55
11.6
11.6
11.6
11.5
11.5
11.55
11.5
MAGNESIUM PLUME
_P_H
8.6
8.8
9.0
8.9
9.2
8.9
8.8
8.9
9.0
9.0
9.2
8.6
8.8
8.9
9.0
8.9
8.7
8.7
TH
WBW^MM
90
90
88
90
91
92
92
94
92
92
87
87
88
89
90
95
99
102
CH
85
82
81
83
86
86
84
84
84
86
85
83
84
85
86
86
88
87
ALK
68
67
64
65
70
68
65
66
64
65
75
72
76
80
76
76
78
72
TURB
Si
6.0
6.0
5.9
5.8
5.0
4,5
4.5
4.5
4.8
5.0
6.0
6.5
5.8
5.5
5.2
5.2
5.3
5.0
AClb
TURB
,ฑ
1.7
1.4
1.3
1.2
1.0
0.8
1.5
1.0
1.0
1.0
1.4
1.4
1.2
1.2
1.0
1.2
1.2
1.0
CARBONATED SLUDGE
pH
7.4
7.4
7.6
7.5
7.5
7.5
7.5
7.5
7.4
7.4
7.45
7.55
7.5
7.6
7.45
7.5
7.4
7.4
ALK
14700
13500
13700
14100
13600
13500
14000
13800
13800
13700
13600
14600
14900
14800
14700
15000
14600
PUMP
SETTING (crpm^
Max
Max
Max
15
15
15
15
15
15
15
15
15
15
8
15
15
15
15
TANK
LEVEI
7.0'
1.5'
2.0'
2.0*
2.2*
3.flซ
2.0'
2.0'
2.0'
4.5'
4.3'
2.5'
1.5'
2.0'
3.0'
3.5'
EFFLUENT
FILTER
#5
PH
8.7
8.9
8.9
8.9
8.9
8.8
8.9
8.9
9.2
9.2
8.9
8.9
8.9
8.9
8.9
8.8
8.7
ALK
58
53
49
51
50
52
54
58
58
68:
67
70
70
72
73
75
69
C02
SETTING
(cfra)
#1
12
12
12
12
12
12
12
12
12
12
1 ?
12
12
12
12
12
12
12
#2
i.d
1.8
1.8
L.8
2.0
4.0
2.3
2.3
2.8
2.8
2.8
2.8
3.0
3.4
3.5
3.5
3.5
3.5
3.5
3.5
3.5
3.3
1 TH-Total Hardness
2 CH-Calcium Hardness
3 MH-Magnesium Hardness
o
w
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
ฃ
DATE
3/26
0800
1000
1200
1400
1600
1800
2000
2200
J/2;
0000
0200
0400
06CO
0800
1000
1200
1400
1600
1800
RAPID MIX
SI
i > i
pH
9.9
9.95
9.9
9.9
0.0
0.0
0.0
0.0
LO.O
9.95
LO.O
9.0
LO.O
.0.0
LO.O
10.0
9.95
10.0
1
2
3
TH
164
135
120
121
130
122
128
132
129
127
130
132
122
130
138
126
130
130
CH
S?
59
41
61
36
34
34
32
37
39
37
36
36
34
42
36
36
36
MH
112
76
79
60
94
88
94
100
92
88
93
96
86
96
96
90
94
94
R M
A I
P X
1 #2
D "^
PH
11.6
11.65
11.3
11.35
11.6
11.7
11.7
J1.65
LI. 5
LI. 6
11.6
11.5
LI. 6
LI. 55
LI. 6
LI. 5
LI. 6
LI. 6
MAGNESIUM FLUME
pH
8.7
R.8
9.25
8.7
7.9
8.1
9.3
9.5
9.5
9.4
9.2
8.8
8.8
8.9
8.8
9.0
8.8
9.0
TH
104
90
90
86
82
80
87
90
90
93
94
96
98
96
98
98
91
96
CH
87
88
85
83
73
72
80
88
86
86
85
87
96
92
90
90
88
91
ALK
94
73
68
68
68
68
73
76
73
74
73
76
80
84
78
80
80
82
TURB
4.5
2.9
5.5
6.8
7.6
6.8
6.0
6.0
6.1
6.4
5.2
4.5
6.9
5.5
9.2
8.5
9.0
9.5
ACID
TURB
1.0
0.8
1.2
1.2
1.6
1.6
1.4
1.4
1.4
1.6
1.3
1.0
0.9
0.9
1.0
0.9
0.9
1.5
CARBONATED SLUDGE
PH
7.4
7.4
7.4
7.45
7.5
7.6
7.6
7.6
7.6
7.55
7.6
7.55
7.55
7.45
7.5
7.45
7.5
7.45
ALK
16100
14500
14200
14300
14300
14200
13900
13600
13800
13600
13800
14000
14400
14500
14200
14400
14200
14100
PUMP
SETTING (qpm)
15
15
15
15
14
14
14
14
15
15
15
15
15
15
15
15
TANK
LEVEI
4.0'
3.0'
4.2'
5.5'
5.0'
5.0'
2.5'
4.0'
3.11
3.3'
0.8'
1.2'
EFFLUENT
FILTER
ง5
pH
8.4
8.85
9.2
8.75
8.5
8.4
8.6
8.8
9.0
9.2
9.0
8.9
8.8
8.7
8.8
8.8
8.8
8.8
ALK
66
68
64
62
66
64
59
66
62
59
61
65
68
62
72
72
75
73
C02
SETTING
(cfm)
U
12
12
12
12
124
124
12
12
12
12
12
14
14
14
14
14
15
15
#2
3.3
3.0
3.0
3.15
J^.o
2.0
#'
/3\0
.os^
/$.*.
4.0
4.0
4.0
4.0
4.0
4.0
4.0
4.0
4.0
TH-Total Hardness
CH-Calcium Hardness
MH-Magnesium Hardness
o
VO
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
3/2 7
2000
2200
3/28
0000
0200
0400
0600
0800
1000
1200
1400
1600
1800
2000
2200
3/29
0000
0200
0400
0600
RAPID MIX
#1
i i >
PH
10. C
10.0
10.1
9.9
9.9
9.9
10.0
10.0
9.9
9.95
.0.1
.0.0
10.0
10.1
in n
10.0
10.0
10.0
TH~
132
132
148
112
118
119
132
130
148
128
145
140
140
142
110
104
110
110
CH"
34
34
65
43
42
41
38
38
34
38
42
40
40
40
35
40
40
MH~
98
98
83
69
76
78
94
92
114
90
103
100
100
102
74
69
70
70
K M
A I
P X
pH
p.1.6
11.6
LI. 75
LI. 6
LI. 6
LI. 6
LI. 6
LI. 6
LI. 6
LI. 8
LI. 7
LI. 6
LI. 6
LI. 65
n .ซซ;
LI. 65
LI. 65
LI. 6
PH
8.9
9.1
8.65
8.7
8.6
8.75
3.8
3.8
3.8
3.8
9.1
J.O
3.0
>.l
3.9
9.4
9.7 '
8.6
MAGNESIUM FLUME
TH
91
88
88
90
91
90
98
90
88
108
82
82
82
84
81
87
88
89
CH
88
86
86
88
87
88
84
80
80
86
75
75
74
78
78
85
86
87
ALK
78
76
76
75
75
78
80
74
68
74
75
72
72
76
66
66
70
68
TURB
9
9
5,9
6.8
5.8
8.0
6.1
5.0
9.2
7.5
7.0
7.0
7.4
6.0
6.0
5.5
5.8
ACID
TURB
1.2
1.2
0,8
1,2
ito
1.3
0.8
0.9
0.9
1.0
1.0
1.0
0.9
1.2
1.2
1.2
1.5
CARBONATED SLUDGE
pH
7.4
7,1)
7,3
7,4
7,4
7,55
7.45
7.4
7.4
7.4
7.4
7.4
7.5
7.5
7.5
7.5
7.4
ALK
14200
14200
14300
13800
14000
14000
14700
14600
14500
13500
13400
14000
14200
14000
14000
13600
14300
14100
PUMP
SETTING (
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
3/29
0800
1000
1200
1400
1600
1800
2000
2200
3/3 U
0000
0200
0400
6600
0800
1000
1200
1400
1600
1800
RAPID MIX
fl
1 01
pH
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
9.95
9.95
9.95'
9.9
3.95
9.95
).95
).9
10.0
1
2
3
TH*
70
Ifi
116
20
18
16
115
18
120
122
125
127
130
124
128
128
126
128
CH"
W
?8
32
32
32
32
32
32
32
32
32
31
30
30
30
28
26
26
MH"
88 :
88
84
88
86
84
83
86
88
90
93
96
100
94
98
100
100
102
R M
A I
P X
;ซ
PH
11.6
11.6
11.5
11.6
11.65
11.6
11.65
11.6
11.6
11.55
11.6
11.6
11.6
11.6
11.6
11.65
11.0
11.7
MAGNESIUM FLUME
pH
9.1e
9.1
9. If
9.2
9.0
8.8
8.4
8.8
9.0
8.9
8.8
8.7
8.5
8.6
8.9
9.1
9.0
9.0
TH
86
90
86
88
85
88
88
85
82
80
82
84
94
88
90
92
90
92
CH
80
86
82
82
82
84
p4
84
77
77
76
78
32
34
30
32
30
30
ALK
70
72
68
68
70
70
68
72
70
66
70
73
64
76
68
68
69
70
TURB
8.2
8.0
7.9
6.2
6.0
6.5
6.5
8vO
7.2
6.7
6.9
7.0
8.0
7.5
5.0
8.4
8.0
8.0
ACID
TURB
1.2
1.1
1.2
3.2
2.0
2.0
2.0
1.0
1.3
1.2
1.4
1.5
0.8
0.9
0.9
1.4
1.5
1.5
CARBONATED SLUDGE
pH
7.6
7.7
7.8
7.7
7.5
7.5
7.5!
7.5
7.5
7.3
7.3
7.3!
7.6
7.4
7.9
7.4
7.4
7.4
ALK
14900
14200
14100
14200
14000
14000
14300
14200
15000
15600
15500
15900
15200
15600
13900
14900
14500
14600
PUMP
SETTING (qpm)
Max
Max
Max
Max
15
14.5
14.5
15
Max
Max
Max
Max
TANK
LEVEI
4.9'
4,0'
4,7'
6.01
6.2'
Foam
Foam
Foam
5.6'
4.4'
5.0'
7.0'
5.5'
EFFLUENT
FILTER
#5
pH
8,95
8.9
8.9
8.85
8.9
8.9
8.9
9.0
3.9
).8
3.8
3.8
8.5
8.6
8.6
8.95
).0
9.0
ALK
68
66 .
62
64
64
66
64
68
15
65
64
65
65
76
62
64
65
64
C02
SETTING
(cfm)
#1
15
14
15
15
15
15
15
L5
3.5
L5
L5
L5
L5
L5
L5
L5
L5
L5
#2
3,6
4,2
4.0
4.2
4.2
4.2
3.5
3.5
3.5
3.5
3.5
2.5
2.5
2.5
2.5
2.5
2.5
TH-Total Hardness
CH-Calcium Hardness
MH-Magnesium Hardness
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
2000
2200
3/31
nnnn
0200
0400
0600
0800
1000
1200
1400
1600
1800
2000
2200
4/1
0000
0200
0400
0600
RAPID MIX
11.
i i V
PH
10.0
10.0
10. OJ
10.0
10. Of
10.1
10.0
10.0
10.1
10.0
10.0
10.0
LO.O
LO.l
LO.O
LO.l
LO.O
).95
TH*
126
124
122
122
116
102
120
174
120
126
128
126
128
130
130
132
130
138
CH"
25
30
34
32
34
36
36
32
34
36
34
32
34
34
40
40
36
34
MH"
101
94
88
90
82
66
84
132
86
90
94
94
94
96
90
92
94
104
K n
A I
P X
PH
11.6
11.65
11.7
11.65
11.6
11.5
11.6
11.6
11.6
11.6
11.65
11.6
11.65
11.65
11.65
11.6
11.55
11.6
pH
9.0
9.0
8.75
9.0
8.9
8.9
9.0
9.0
9.8
9.5
9.4
8.8
8.0
8.5
8.2
9.2
9.2
9.1
MAGNESIUM FLUME
TH
94
94
88
87
88
89
92
88
58
88
80
85
87
85
95
94
98
98
CH
32
34
36
36
)4
84
84
82
55
82
80
80
82
82
90
90
94
94
ALK
72
72
71
70
70
71
70
72
72
72
70
72
70
72
76
77
74
76
TURB
.8.0
7.5
7.5
7.0
7.2
7.0
8.9
15
18
18
16
10
5.5
6.0
6.3
7.2
7.0
7.0
ACID
TURB
1.0
1.5
1.2
1.2
1.1
1.2
1.6
1.7
2.0
1.5
?,.o
2.0
210
1.5
1.6
1.2
1.0
1.0
CARBONATED SLUDGE
pH
7.4
7.4
7.8
7.6
7.7
7.7
7.9
7.7
7.3
7.3
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.35
ALK
14400
14200
14300
14400
14200
14000
12600
13800
15500
15700
14900
14500
14400
14500
15000
15100
15000
14900
PUMP
SETTING (com)
12
12
12
8
Max
Max
Max
Max
Max
Max
Max
Max
Max
TANK
LEVEI
5.5'
5.8ซ
4.8'
5.2'
3.2'
4.0'
3.5'
4.01
4.1'
3.0
6.0'
6.0'
Full
Full
Full
F.ull
Full
Full
EFFLUENT
FILTER
#5
pH
9.0
9.0
8.8
8.9
8.9
8.8
8.8
9.05
9.3
).15
9.2
9.0
9.0
8.9
8.5
8.8
8.9
8.8
ALK
64
66
62
62
62
64
62
58
50
52
50
50
52
54
82
83
70
64
C02
SETTING
(cfm)
#1
.5
15
18
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
#2
2.5
2.5
2.7
2.7
2.7
2.7
2.7
3.0
3.5
4.0
3.5
3.0
3.0
3.0
3.4
3.0
3.5
3.7
1 TH-Total Hardness
2 CH-Calcium Hardness
3 MH-Magnesium Hardness
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
4/1
nano
1000
1200
1400
1600
1800
2000
2200
4/2
1800
2000
2200
4/3
000
0200
0400
0600
0800
1000
RAPID MIX
#1
i 11
J3H
.9
0.0
.95
0.3!
0.1
0.0
.9
9.9
9.8
9.8
9.8
9.75
9.9
9.95
9.9
9.8
9.9
TH*
150
146
152
84
95
96
120
118
105
105
110
110
112
114
110
122
107
CH
32
46
42
38
36
34
34
34
3?
3?
3?
40
36
34
34
33
33
MH"
119
100
110
46
59
62
86
84
73
70
78
70
76
80
76
89
74
R M
A I
P X
1 #2
D "^
pH
11.55
11.55
11.55
11.75
11.6
11.65
11.6
11.7
11.5
11.65
11.6
11.6
11.7
11.7
11.6
11.6
11.75
MAGNESIUM FLUME
pH
8.55
9.2
9.0
8.8
8.8
8.9
9.2
9.3
9,4
9.2
9 3
R ?
ft.")
R.R
9.R
9.B
9.3
TH
100
94
100
98
98
98
100
98
9?
95
94
96
96
95
97
96
105
CH
98
90
100
98
96
95
96
94
90
90
92
94
94
93
93
89
96
ALK
64
70
80
84
85
84
82
80
72
74
78
75
76
78
76
75
77
TURB
6.4
5.2
5.3
4.4
5.0
5.5
5.0
5.0
^
3,5
5.5
5.2
6.6
7.0
7.0
6.0
5.6
5.2
ACID
TURB
1.3
1.2
1.4
2.0
2.0
2.5
2.0
2.0
1,5
1.5
1.6
2.0
2.0
1.9
1.5
1.6
1.5
CARBONATED SLUDGE
pH
7.45
7.4
7.5
7.2.
7.4
7.4
7.5
7.4
7,6
7.4
7.35
7.6
7.6
7.6
7.65
7.3
7.5
ALK
13600
13600
13800
15600
14800
14600
14200
14200
15800
15900
16200
16300
16400
16700
16000
16800
14900
PUMP
SETTING (qpm)
Max
Max
Max
Max
Max
Max
Max
Max
Max
TANK
LEVEI
0.8'
1.0'
2.6'
5.01
Full
Full
Full
4*5'
3,0'
6.01
2.51
2.0'
2.0'
3.0'
EFFLUENT
FILTER
#5
pH
8.65
8.05
8.75
1.7
8.8
8.9
9.0
9.1
__
_ _
__
_
-
ALK
64
80
68
66
66
68
68
68
__
__
_
__
CO 2
SETTING
(cfm)
U
16
16
15
15
15
15
15
15
'VHJ
14
%
*
17
17
17
X,
18
#2
3.0
3.0
2.0
2.0
2.0
2.0
3.5
4.5
Ful
Full
4\41
^O
3.0
3.0
3.5
y
/4.0
4.2
H
H
U)
1 TH-Total Hardness
2 CH-Calcium Hardness
3 MH-Magnesium Hardness
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
4/3
1200
1400
1600
1800
2000
2200
4/4
0000
0200
0400
0600
*0800
1000
1200
1400
1600
1800
2000
2200
RAPID MIX
' #1
i > >
PH
9.8
9.8
9.9
9.9
9.9
9.9
9.9
9.9
9.9
9.9
9.95
9.75
9.8
9.9
9.9
9.85
9.8
9.9
TH*
124
111
115
120
115
116
110
110
106
104
102
110
115
121
128
130
130
132
CH'
33
34
32
34
34
34
34
34
34
34
39
35
35
38
34
38
36
36
MHW
91
87
83
86
81
82
76
76
72
70
63
75
80
83
94
92
94
96
R M
A I
P X
i^
pH
11.6
11. 6f
11.6
11.6
11.65
11.6
11.55
11.5
11.5
11.5
11.95
11.5
11.3
11.65
11.6*5
11.6
11.6
11.65
MAGNESIUM FLUME
pH
9.2
9.2
9.1
9.4
9.3
9.1
9.4
9.3
8.5
8.8
8.0
7.8
8.6
8.1
7.9
9.4
9.3
8.7
TH
96
106
100
98
98
100
93
93
91
89
91
91
90
87
86
84
86
88
CH
92
98
98
97
66
96
91
90
88
86
88
87
85
81
81
80
82
82
ALK
76
80
78
74
74
75
78
78
76
74
70
75
72
70
72
70
70
70
TURB
5,1
4.0
4.5
4.5
5.0
80
8.0
7.5
7.0
7.8
6.5
5.7
5.5
5.3
8.5
14
15
1.5
ACID
TURB
1.5
1.6
1.5
1.8
1.5
1.5
1.5
1.8
1.7
1.9
2.0
1.8
2.0
2.4
2.5
2.5
2.4
1.8
CARBONATED SLUDGE
pH
1,*
7. 45
7.7
7.5
7.5
7.5
7.7
7.6
7.6
7.6
7.45
7.5
7.5
7.7
7.5
7.35
7.4
7.4
ALK
15800
15100
16000
15500
15800
15800
14900
14900
14900
14700
14700
14800
15000
13000
15300
15500
15400
15600
PUMP
SETTING (qpm)
Max
Max
Max
Max
Max
Max .
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
TANK
LEVEI
5,5'
5.01
6.01
6.5'
6.0'
6.0'
6.3'
6.5'
5.0'
Pull
5.4f
5.10
5.10
4.0'
3.5'
4.2'
5.0'
EFFLUKNT
FILTER
15
pH
_
B^
BW
V
^^
ซ^
ซMH
__
ซ
__
.._ '
-~
~
ALK
ป_
w
__
ซซ
mtmt
.
__
__
-*,
__".,.
C02
SETTING
Ccfm)
#1
%*
14
Lv
At
17
17
17
17
18
17+
17-
17
17
17
17
16
16
16
16
#2
xSax
4./
/M,Q
4.IX
/*,5
4.5
4.5
4.5
4.5,
4.5
4.5
4.0
4.0
J.j>
^.5
2.5
^JK
Sl.Q
*-y
/2.0
X3.0
TD/^
/$.*
2.8
1 TH-Total Hardness ' * Increased lime .5 at 0800 - decreased .5 at 0820
2 CH- Calcium Hardness
3 MH-Magnesium Hardness
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
4/5
nnnn
0200
0400
0600
0800
1000
1200
1400
1600
1800
2000
2200
4/6
0000
0200
0400
0600
0800
1000
RAPID MIX
#1
1 10
pH
9.9
9.8
9.9
9.8
9.9
9.95
9.9
9.8
9.8
9.7
9.8
9.75
9.9
9.9
9.9
9.9
9.95
9.8
TH"
132
128
126
124
133
121
118
120
130
no
no
120
122
1?R
no
122
125
CH"
34
32
32
34
33
34
33
33
16
36
38
34
32
16
36
36
35
MH"
98
96
94
90
100
87
85
87
94
98
94
96
86
90
92
94
86
90
K n
A I
P X
I
D
PH
11.65
11.6
11.7
11.6
11.6
11.6
11.6
11.6
11.6
11.65
11.6
11.65
11.65
11.65
11. 6E
11.65
11. 6ฃ
11.6
MAGNESIUM FLUME
PH
8.9
9.1
8.85
9.0
8.6
8.85
8.9
9.2
9,1
9.05
9 OS
9.1
9.15
9, IS
9.05
9.1
8.5
8.6
TH
90
89
88
91
94
92
93
88
90
90
90
9fl
91
91
95
93
97
95
CH
88
86
86
89
88
89
90
84
84
84
RR
90
flfi
88
90
88
90
88
ALK
73
72
71
71
69
72
70
71
70
70
74
68
69
72
74
72
68
70
TURB
5.5
6.7
6.0
7.5
6.1
5.5
5.0
6.2
5,3
5.2
7.5
6.2
5.6
7.2
6.0
7.0
6.1
5.6
ACID
TURB
1.5
1.5
1.4
1.7
1.5
1.4
1.2
1.5
1,1
1.3
1.0
1.0
1.1
1.2
1.2
1.1
1.0
1.0
CARBONATED SLUDGE
pH
7.5
7.6
7.5
7.35
7.25
7.7
7.4
7.5
7,4
7.3
7.4
7.4
7.6:
7.6
7.6
7.45
7.65
7.5
ALK
15000
14800
15000
15700
16000
15800
15600
15300
16000
15500
15000
15800
15900
15900
15700
16000
15800
16100
PUMP
SETTING (qpm)
Max
Max
Max
Max
MAX
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
TANK
LEVEI
5.4'
5.81
6.4'
6.8'
6.0'
4.0'
3.5'
3.0'
4.6'.
4.6'
4.6'
4.6'
6.5'
6.5
6.0'
5.8'
5.6'
4.3'
EFFLUENT
FILTER
#5
PH
._
__
_
ALK
__
__
__
C02
SETTING
(cfm)
#1
16
16
16
16
15
15
15
15
15
15
15
15
15
15
15
15
15
15
#2
2.8
> ay
ZTy
/3 . 0
3.0
3.0
3.0
3.0
3.0
^5
3,5.
3.5
3.5
3.5
3.5
3.5
3.6
3.7
3.7
3.7
1 TH-Total Hardness
2 -CH-'Cal-ciuirr Hardness
3 MH-Magnesium Hardness
-------
MONTGOMERY DEMONSTRATION OPERATING DATA
TIME
&
DATE
4/6
120C
1400
1600
1800
RAPID MIX
v * i
pH
9.8
9.8
9.7
9.8
TH*
115
111
122
128
CH~
36
32
30
32
MH
79
79
92
94
K M
A I
P X
PH
11.7
11.6
11.6
11.2!
MAGNESIUM PLUME
pH
8.1
8.5
8.9
9.25
TH
91
90
B6
86
CH
84
84
78
82
ALK
74
73
54
.72
TURB
6.0
5.8
6.5
7.4
ACID
TURB
1.2
1T3
1.6
1.1
CARBONATED SLUDGE
pH
7.2
7,4
7,4
7.4
ALK
15800
15300
17700
PUMP
SETTING (ctDro)
Max
Max
Max
Max
TANK
LEVEI
J.5'
3.2'
4.3'
4.7'
EFFLUENT
FILTER
#5
pH
*
ALK
_ป
..
CO 2
SETTING
(cfm)
#1
.5
15
16
16
#2
^zL
3.2
2.9
1 TH-Total Hardness
2 CH-Calciura Hardness
3 MH-Magnesium Hardness
-------
APPENDIX B
VACUUM FILTER TESTS,
MONTGOMERY, ALABAMA
-------
MAGNESIUM CARBONATE PROCESS
Sludge Handling Data
(March 13, 1973)
Time
8 a.m.
9 a.m.
10 a.m.
LI a.m.
12 N
1 p.m.
2 p.m.
3 p.m.
Feed
Sludge
Solids
(%)
STA
43.3
41.2
40.5
39.1
Filtrate
Alk
RTED
Solids
(g/ft2)
406.2
343.8
280.2
289.8
Drum
Speed
(RPM)
1.25
1.25
1.25
1.25
Filter
Rate
(Ib/ft2/hr)
7.4
6.3
5.1
5.3
Cak
(
Ca
430
e A
As
Mg
54
nalysis
CaCO,)
J%
Moisture
38.7
37.8
46.7
45.2
Belt
Setting
.5
.5
.5
.5
00
-------
MAGNESIUM CARBONATE PROCESS
Sludge Handling Data
(January 11, 1973)
Time
9 a.m.
10 a.m.
11 a.m.
12 N
1 p.m.
2 p.m.
3 p.m.
Feed
Sludge
Solids
(%)
STA
NO CAKE
35.7
36.1
LINE 1C
38.3
35.3
Filtrate
Alk
RTED
ED UP
Solids
(g/ft2)
209.4
205.2
190.2
173.4
Drum
Speed
(RPM)
.88
.88
.
.88
.88
Filter
Rate
(Ib/ft2/hr)
2.7
2.6
2.5
2.2
CaJ
Ca
492
482
te A
[As
Mg
52
64
nalysis
CaC03)
%
Moisture
40.8
40.7
40.0
42.6
Belt
Setting
0
0
0
0
H
M
VO
-------
MAGNESIUM CARBONATE PROCESS
Sludge Handling Data
(March 12, 1973)
Time
8 a.m.
9 a.m.
10 a.m.
11 a.m.
12 N
1 p.m.
2 p.m.
3 p.m.
4:30
p.m.
Feed
Sludge
Solids
(%)
ST
38.6
44.3
43.6
43.2
CLOSED
Filtrate
Alk
&RTED
7,800
Solids
(9/ft2)
466.8
384.6
387.0
354.6
Drum
Speed
(RPM)
.88
.88
1.25
1.25
1.25
1.25
1.25
1.25
1.25
Filter
Rate
-------
MAGNESIUM CARBONATE PROCESS
Sludge Handling Data
(January 17, 1973)
Time
8:30 am
9 am
10 am
11 am ,
12 N
1 pm
2 pm
3 pm
Feed
Sludge
Solids
(*)
PILT
14.2
20.1
27.9
29.9
31.3
35.1
32.3
Filtrate
Alk
ER ON
Solids
(g/ft2)
190.2
198.6
219.0
184.2
184.2
165.6
191,4
Drum
Speed
(RPM)
.88
.88
.88
.88
.88
.88
.88
Filter
Rate
(Ib/ft2/hr)
2.2
2.3
2.6
2.2
2.2
1.9
2.2
Ca
Ca
440
470
ke A
(As
Mg
56
62
nalysis
CaCO3)
%
Moisture
43.7
45.4
46.6
43.5
48.5
45.0
45.9
Belt
Setting
0
0
0
0
0
0
0
0
N)
-------
MAGNESIUM CARBONATE PROCESS
Sludge Handling Data
(February 21, 1973)
Time
9 am
LO am
LI am
12 N
1 pm
2 pm
3:30
pm
1:20
pm
Feed
Sludge
Solids
(%)
STAR
41.6
46.9
42.2
CLOSED
Filtrate
Alk
FED
7,500
Solids
(9/ft2)
3.012
3.018
3.288
Drum
Speed
(RPM)
.88
.88
.88
.88
.88
.88
.88
.88
Filter
Rate.
(Ib/ft2/hr
3.9
3.9
4.2
Ce
Ca
396
ike Ar
(As C
Mg
56
lalysis
:aC03)
%
Moisture
35.8
35.2
35.8
Belt
Setting
to
to
-------
MAGNESIUM CARBONATE PROCESS
Sludge Handling Data
(January 18, 1973)
Time
9 am
10 am
11 am
12 N
1 pm
2 pm
3 pm
4 pm
Feed
Sludge
Solids
(%)
STAF
26.9
MISSE
33.1
33.0
' 31.7
32.1
30.8
Filtrate
Alk
TED FILTER
D
Solids
(g/ft2)
148.8
154.2
185.4
154.8
162.0
135.0
Drum
Speed
(RPM)
.88
.83
.88
.88
.88
.88
Filter
Rate
(Ib/ft2/hr)
1.9
2.0
2.4
2.0
2.1
1.7
C
Ca
456
508
ake -
(As
Mg
96
60
Analysis
SaCOo)
%
Moisture
43.5
45.4
47.0
45.0
46.3
46.3
Belt
Setting
0
0
0
0
0
0
0
NJ
CO
-------
MAGNESIUM CARBONATE PROCESS
Sludge Handling Data
(February 23, 1973)
Time
8:15
am
9 am
10 am
11 am
12 N
1:30
pm
2 pm
3 pm
4 pm
4:25
pm
Feed
Sludge
Solids
(%)
STARTS
43.4
43.7
39.9
24.2
CLOSED
Filtrate
Alk
D
7,400
Solids
(g/ft2)
303.0
307.2
353.4
169.5
Drum
Speed
(RPM)
.88
.88
.88
.88
.88
.88
.88
.88
Filter
Rate
(Ib/ft2/hr)
3.9
4.0
4.6
2.3
Ca
Ca
344
ke I
(A3
Mg
34
Analysis
CaC03)
%
Moisture
36.796
37.408
36.393
Belt
Setting
H
to
-------
MAGNESIUM CARBONATE PROCESS
Sludge Handling Data
(February 28, 1973)
Time
9 am
11 am
1 pm
2 pm
3 pm
Feed
Sludge
Solids
(ft)
50.7
57.1
49.9
50.4
49.5
Filtrate
Alk
Solids
(g/ft2)
586.2
684.6
451.8
310.8
349.2
Drum
Speed
(RPM)
.88
.88
1.25
1.666
2.727
Filter
Rate
(Ib/ft2/nr)
7.6
8.8
8.3
7.6
14.0
C
Ca
334
ake A
(As
Mg
38
nalysis
CaCOa)
%
Moisture
34.43
34.31
36.18
35.25
35.33
Belt
Setting
0
0
.5
1.0
2.0
to
-------
MAGNESIUM CARBONATE PROCESS
Sludge Handling Data
(March 5, 1973)
Time
8 am
11 am
1 pm
2 pm
Feed
Sludge
Solids
(%)
49.5
48.8
49.2
43.9
Filtrate
Alk
9,000
Solids
(g/ft2)
450.6
529.2
409.2
367.2
Drum
Speed
(RPM)
1.666
1.25
1.666
1.666
Filter
Rate
(Ib/ft2/hr)
11.0
9.7
10.0
9.0
C
Ca
524
ake i
(As <
Mg
35
Analysis
2aC03)
%
Moisture
38.08
37.84
39.05
40.29
Belt
Settinc
1.0
.5
1.0
1.0
-------
APPENDIX C
ROUTINE DATA SHEETS,
MELBOURNE, FLORIDA
-------
CITY of. MELBOURNE. FLOHlBA
WATER TRBATMEHT PLANT
1VTE
Treatment with MgCO^ as ? Recycled Coagulant ^AY
CENTER
CLARIFIER
(WEIR)
FILTERED PIHISHBO WATER
SLUDGฎ
CAnOCNATOa
TIHE
HJ
o
a
\~
ซ :
8
p.
0
0100
/a
.7
/ty
0200
1-U
75
OJOO
ii.V
csr
.s
OkOO
QgOO
i/a
IU
13
O
'V
0600.
0700
0800
'ttt
ฃ25
0900
1000
IIOO
ll-tif
u
lo
1200
11$
1300
It.
IIj.00
1500
I/'
1600
lf;S
i.7
;!ฃ
.1700
?.*
M.
U
: 1800
10
i 1900
2000
i-.t.
2*
2100
''*
2200
30
2300
//.f*
0
AVG.
wo
sas
I3S
30
RAW WATER
SHIFT
OPERATCR
o.,
fii
y'3
r.-:rS^l73l79
Hardness
&ปU
t
20
50
vv
/Z
ri.
//
32
3V
73
2400-0800
0800-1600
1600- 24OO
. REMARKS
128
-------
DATS!
TIME
i2.-,AN
1AM
I:N NJ
vo
RAW
MGD
'5
/ J
Make-
CPif
i r
/r
/ JT
3L|
T
'Xf
C02
Valr Sludgq
OPK CPK
Mr
06
iA.
1^_
Ol'l'i of i-ii.JLit>v;uixi>iCiป t'owuAL/.t
NORTH WAT2H TREATMENT PLANT
Trottraent vrith MgCOj as a R-Jojrolsd Coagulant ^
~H 0:"D HBTER READIN^
COAC5ULANT
AID
Pump
Set.
3.$
'L, r
^fL/
Min
Time
Mix
LIME
Maoh,
Set.
313
37S
775-
Lbs.
Load
(RAW) # I SIDE ! OPMATOM ^
12- e ...L^Ox-U
PRESENT
PREVIOUS
MOD .
FUH?BD i '
FILTERS
PftES. WASH
PREV. WASH
HRS. RUN
B.W. END
B.W. START
GALS. USED
GAL/MIN,
MIN. WASH
iฃ
I*
8- <_
4-)2_
#2
a C
REMARKS
CHEMICAL INVENTORY
"ซ'
1-3.'
QUICK
LIMg
Pounds
on hand
COAGU-
LANT AID
C0
CKLOR|NE
CA)iBON
i e
If
LJL
fb
I2V.N
Used
Poundป
on hand
P. P. M;
-------
APPENDIX D
SUMMARY OF DAILY AVERAGE RESULTS
MELBOURNE, FLORIDA
-------
Date
Raw Water Coagulation Filtered Water
Magnesium
9/13/73
9/14/73
9/15/73
9/16/73
9/17/73
9/18/73
9/19/73
9/20/73
9/21/73
9/22/73
9/23/73
9/24/73
9/25/73
9/26/73
9/27/73
9/28/73
9/29/73
10/1/73
10/2/73
10/3/73
10/4/73
10/5/73
10/6/73
10/7/73
10/8/73
10/9/73
10/11/73
10/12/73
10/16/73
10/17/73
10/18/73
10/19/73
10/20/73
10/21/73
10/22/73
10/23/73
10/24/73
10/25/73
10/26/73
10/27/73
10/28/73
10/29/73
10/30/73
10/31/73
11/1/73
11/2/73
11/3/73
11/4/73
11/5/73
11/6/73
11/7/73
11/8/73
11/9/73
12.66
12
11.3
13.3
12
15.3
14
12
14
12
15
14
14
12
12
14
12
15
10
12
12
11
7
8
10
11
7
6
9
15
11
7
10
13
5
8
9
8
8
ii
11
6
13
28
11
11
8
Color
195
215
230
220
227
200
208
208
185
178
175
183
175
175
176
190
208
175
167
158
216
200
188
222
192
175
167
195
172
147
177
138
138
138
183
125
175
183
148
116
146
146
130
150
185
127
147
PH
11.35
11.31
11.27
11.31
11.28
11.37
11.43
11.29
11.39
11.38
11.4
11.44
11.45
11.38
11.43
11.41
11.41
11.29
11.41
11.45
11.38
11.35
11.38
11.33
11.33
11.35
11.28
11.33
11.24
11.4
11.2
11.24
11.34
11.25
11.27
11.25
11.27
11.25
11.28
11.64
11.36
11.23
11.2
11.32
11.26
11.22
11.3
11.5
11.26
11.33
11.4
11.26
11.29
Hardness
Total Magnesium
157
172
132
152
173
181
146
167
117
137
154
171
126
130
141
141
124
155
111
133
137
171
164
169
204
132
112
117
196
166
158
183
204
211
209
226
191
184
196
221
215
195
154
154
185
186
153
161
155
186
198
171
165
2.4
10.0
7.3
10.3
6.0
6.67
7.33
7
5.3
6.3
11
8.3
3
2
2.8
5.6
4.5
4
3
3.5
9
5
11
6
13
5
2
4.6
5
6.8
8
1.5
4.6
10
4.66
5.7
4.7
7
7
0
7
12
8
6
4
10
5
12
7
8
-6
6
4
Carbonated Sludge
Color Alkalinity
35.4
44.8
35.3
37.4
38.7
47.9
42
59
30
38.6
36
41.8
36
41
42.7
36
38
39
35
36
91
34
26
31
35
29
30
34
34
36
34
34
33
34
33
38
34
37
32.5
36
41
33
28
31
31
31
33
28
29
30
30
30
23
20,666
23,166
21,083
21,333
20,900
22,000
27,700
11,733
11,333
9,866
8,134
9,033
8,966
8,633
7,866
7,000
8,333
7,300
6,543
6,350
7,433
7 , 100
7,400
6,366
6,100
6,400
5,616
5,053
5,900
6,200
4,833
6,250
6,233
5,800
5,770
5,367
5,766
5,566
6,040
4,050
5,167
5,800
6,900
4,700
5,400
5,366
5,333
5,800
5,967
6,700
7,567
6,280
5,967
Color
15,400
18,666
14,066
13,516
13,800
12,033
18,000
14,750
17,250
14,166
11,884
10,750
10,000
9,750
10,083
9,666
11,416
7,250
6,350
7,083
6,916
7-,000
7,100
3,983
6,600
5,700
6,116
7,316
6,850
7,640
5,350
6,925
5,500
5,930
5,430
4,917
5,255
7,633
6,940
11,250
7,316
6,700
7,233
4,900
4,233
5,350
6,566
6,016
4,283
6,250
7,267
5,400
6,733
131
-------
Date Raw Water Coagulation Filtered Water
Magnesium
11/11/73
11/12/73
11/13/73
11/14/73
11/15/73
11/16/73
11/17/73
11/18/73
11/19/73
11/20/73
11/21/73
11/22/73
11/23/73
11/24/73
11/25/73
11/26/73
11/27/73
11/28/73
11/29/73
11/30/73
12/1/73
12/2/73
12/3/73
12/4/73
12/5/73
12/6/73
12/7/73
12/8/73
12/9/73
12/10/73
12/11/73
12/12/73
12/13/73
12/14/73
12/15/73
12/16/73
12/17/73
12/19/73
12/20/73
12/21/73
12/22/73
12/23/73
15
15
14
13
19
12
12
9
12
7
11
7
13
14
17
13
5
7
6.3
12
8
10
8
12
11
16
8
8
17
9
12
11
12
9
9
14
10
10
14
19
9
16
Color
150
138
142
168
142
175
150
133
147
133
142
147
147
166
160
134
133
142
183
142
130
129
158
150
157
142
167
163
183
125
113
133
142
125
133
138
252
125
152
208
193
125
PH
11.4
11.4
11
11.38
11.3
11.9
11.4
11.3
11.38
11.33
11.38
11.35
11.44
11.4
11.32
11.3
11.3
11.3
11.45
11.47
11.45
11.4
11.35
11.52
11.45
11.5
11.5
11.6
11.65
11.7
11.53
11.5
11.6
11.6
11.6
11.5
11.6
11.5
11.6
Hardness Color
Total Magnesium
209
175
218
197
206
212
192
205
201
192
201
177
139
184
195
190
155
179
172
185
151
122
134
192
226
226
246
244
200
197
252
210
229
236
207
170
216
222
5
5
10
5
6
5
7
6
2
2
5.3
1.6
5.6
5
4
7
8
4
3.6
13
4
13
9
5.5
8
4
6
5
4
12
4
4
14
7
1
7
5
5
7
32
26
34
42
34
39
33
36
31
29
28
23
36
27
37
40
34
34
27
31
24
29
30
29.1
34
30
26
13
12
11
11
10
9
21
15
20
19
21
22
Carbonated Sludge
Alkalinity Color
6,167
6,267
6,600
7,400
8,400
9/550
10,520
11,83-3
7,400
8,560
8,700
8,160
8,080
8,600
8,680
7,850
8,700
9,200
6,966
7,333
8,740
8,266
6,800
6,500
6,120
6,570
6,560
6,800
6,900
8,633
7,200
7,467
6,700
6,600
6,800
6,880
7,760
8,267
6,700
7,920
7,100
6,800
5,067
6,650
6,167
7,200
7,317
10,500
11,100
12,500
6,800
8,880
11,680
9,500
10,200
10,300
8,800
8,500
7,700
9,300
4,883
6,750
9,000
7,733
6,600
5,750
4,920
5,550
5,900
5,800
6,025
7,400
6,143
5,800
5,350
4,500
4,983
5,200
6,960
7,467
5,317
8,200
5,717
8,340
132
-------
APPENDIX E
E.P.A. ANALYSIS FOR HEAVY METALS AND COMMENTS,
MELBOURNE, FLORIDA
-------
RESULTS OF TRACE ANALYSIS, MELBOURNE, FLORIDA
PERFORMED BY SOUTHEAST ENVIRONMENTAL
RESEARCH LABORATORY, U.S.E.P.A., ATHENS, GEORGIA
Parameters
Chloride
Sulfate
Sodium
Lithium
Barium
M.B.A.S.
Arsenic
Selenium
Cyanide
Chromium
Silver
Copper
Manganese
Lead
Iron
Cobalt
Cadmium
Zinc
Nickel
Raw
Water
50
<25
20
^0.05
^0.25
<0.005
^.0.005
^0.02
0.00
0.00
0.00
0.00
0.00
0.24
0.00
0.00
0.031
0.00
Magnesium
Treated Water
48
<25
20
^0.05
.02
0.00
0.00
0.009
0.00
0.00
0.025
0.00
0.00
0.076
0.00
Alum
Treated Water
46.0
47.0
20.0
^0.25
<0.005
O.02
0.00
0.00
0.017
0.006
0.00
0.046
0.00
0.00
0.19
0.00
134
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Southeast linvironnirnta ! KeGeurdi Laboratory, College
SLnt Ion Road, Athens, Georgia 30601
SUBJECT: Oirj-nnic Analysis of Samples from North Melbourne DATE: December 14, 1973
W.iter Treatment Plant
FROM: AASC/Finger
TO: Gary llutchiiison
Summary
There were no organic chemicals detected in the three water
samples taken November 1973 from various sources in the treatment
process. The analysis was by gas chroma tog raphy, therefore only
organics that vaporize under our GC conditions would be detected.
Action
Transmittal of data.
Background
Your memo of October 5, 1973 to Mr. John A. Little.
^^ James H. Finger
Chief
Chemical Services Branch
PA Form 1320-5 (Rev. 6-72)
135
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Southeast Kiivironmrntal Ki>sean:h Laboratory, College
Station Road, Athens, Georgia 30601
SUBJKCT: Significance of Organic Analysis of North DATE: January 8, 1974
Melbourne Samples
FROM: 4ASC/Finger
j(i; 4AV,iw/llutch inson
Summary
This memo is to provide further comment on our organic
analysis of the three North Melbourne, FL Water Treatment Plant
samples received November 15 and labeled Alum, Raw and Mag. The
sampling dates were not reported to us.
As I mentioned in my last memo on these samples, we used gas
chromatography for analyzing the samples, therefore we would only
detect organics that vaporize at our GC operating conditions. CCE
and CAE data can't be compared to GC data because they are based
on the weight of the residue remaining after evaporating the
chloroform and aocohol extracts. Since these samples are from
Florida I would guess that the CCE and CAE could consist of high
boiling natural organics that do not vaporize at GC conditions
such as the tannic acids.
Action
For your information.
Background
Further comment pertaining to my memo of December l/i, 1973,
James II. Finger
Chief
Chemical Services Branch
EPA liefo 1320-6 (Brv. 6-72)
136
-------
APPENDIX F
PHOTOGRAPHS OF THE MONTGOMERY
AND MELBOURNE FACILITIES
-------
Melbourne Full Scale Facility
Melbourne Vacuum Filter
138
-------
Montgomery Pilot Plant Facility
Montgomery Full Scale Magnesium
Recovery Facilities
139
-------
Plant Scale Study Facilities,
Montgomery, Alabama
140
-------
TECHNICAL REPORT DATA
(I'lftise read Instructions on the reverse before completing)
i in run i NO.
EPA-660/2-75-006
l.'tlfl. I. AND SUIItl I Lt
Plant Scale Studies of the Magnesium
Carbonate Water Treatment Process
3. RECIPIENT'S ACCESSIO!ปNO.
5. REPORT DATE
September 1974
6. PERFORMING ORGANIZATION CODE
8, PERFORMING ORGANIZATION REPORT NO.
A. P. Black
C. G. Thompson
u PI HMJHMINU ORC- -VNtZATION NAME AND ADDRESS
Black, Crow & Eidsness, Inc.
777 South Lawrence Street
Montgomery, Alabama
10. PROGRAM ELEMENT NO.
IB!
11. CONTHACT/G
12120 HMZ
NO.
\] SPONSORING /\r,t NCY NAMt AND ADDRESS
Montgomery Water & Sanitary Sewer Bd,
P. O. Box 1631
Montgomery, Alabama 36102
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
10. SUPPl.tMlNTAHY NOTES
W. ABSTRACT
The magnesium carbonate process of water treatment has re-
placed alum in a portion of two water plants in full scale
studies conducted over the past two and one-half years. This
new water treatment technology was compared to the presently
used alum process in parallel treatment using identical units
in Montgomery, Alabama and Melbourne, Florida.
The results indicate a number of significant advantages;
primarily that the existing problem of sludge disposal in
Melbourne's case is completely eliminated and at Montgomery
is greatly reduced. All water is recycled within the process
along with the three basic water treatment chemicals - lime,
magnesium bicarbonate, and carbon dioxide. Other advantages
found were increased floe settling rates, simplicity of oper-
ation and control, reduced costs when sludge treatment and
disposal costs are considered, and more complete disinfection,
In Melbourne's case, considerable energy would be conserved
by on-site lime recovery.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Water Purification
Coagulation
Chemical Recovery
Sludge Treatment
Magnesium Carbonate
b.lDENTIFIERS/OPEN ENDED TERMS
Recycle
Recovery
Carbonation
Magnesium
c. COSATi Field/Group
11 mr.rmiiunoN STATLMENT
Release unlimited
19. SECURITY CLASS (This Report)
21. NO. OF PAGES
20. SECURITY CLASS (TMipage)
22. PRICE
EPA Form 2220-1 (9-73)
-------
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