WATER POLLUTION CONTROL RESEARCH SERIES
15020 DHG 09/71
Watercraft Waste Treatment
System Development and
Demonstration Report
*ป<"''"""'.
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PROTECTION AGENCY RESEARCH AND MONITORING
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WATER POLLUTION CONTROL RESEARCH SERIES
The Water Pollution Control Research Series describes the results
and progress in the control and abatement of pollution in our
Nation's waters. They provide a central source of information on
the research, development, and demonstration activities in the
Environmental Protection Agency, through inhouse research and
grants and contracts with Federal, State, and local agencies,
research institutions, and industrial organizations.
Inquiries pertaining to Water Pollution Control Research Reports
should be directed to the Head, Project Reports System, Office
of Research and Monitoring, Environmental Protection Agency,
Room 801, Washington, D. C. 20242.
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WATERCRAFT WASTE TREATMENT SYSTEM
DEVELOPMENT AND DEMONSTRATION REPORT
BY
GENERAL ELECTRIC COMPANY
RE-ENTRY AND ENVIRONMENTAL SYSTEMS DIVISION
PHILADELPHIA, PENNSYLVANIA 19101
FOR THE
ENVIRONMENTAL PROTECTION AGENCY
PROGRAM 15020 DHG
SEPTEMBER 1971
For sale by the Superintendent of Documents, U.S. Government Printing Office
Washington, D.C., 20402 - Price $1.25
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EPA REVIEW NOTICE
This report has been reviewed by the Office of Research and Monitoring,
Environmental Protection Agency, and approved for publication. Approval
does not signify that the contents necessarily reflect the views and policies
of the Environmental Protection Agency, nor does mention of trade names
or commercial products constitute endorsement or recommendation for use.
11
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ABSTRACT
A demonstration program of electro-chemical processing of shipboard sani-
tary, culinary, and laundry wastes including prolonged sea trials on board a
large vessel was conducted. Extensive analytical results are presented demon-
strating ability to produce effluent of secondary water quality standard and to
incinerate system by-products. Substantial data for the design of shipboard
systems is also presented.
The economic viability of the treatment system developed is analyzed and com-
pared with alternative approaches with the conclusion that dependence of large
vessels on shore side facilities in conjunction with on-board holding equipment
is eliminated in many cases.
The program demonstrates the unique character of shipboard wastes and the
shipboard environment verifying the need for specially developed equipment
for treatment such as the system demonstrated.
The program suggests further extension of the capabilities of the system de-
veloped for increase in capacity and for elimination of other ships wastes such
as bilge water and wet and dry garbage.
This report was submitted in fulfillment of Contract Number 14-12-522 under
the sponsorship of the Office of Research and Monitoring, Environmental Pro-
tection Agency.
111
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TABLE OF CONTENTS
Section Page
EPA REVIEW NOTICE .......................... ii
ABSTRACT ................................. iii
TABLE OF CONTENTS ......................... v
LIST OF ILLUSTRATIONS .........I............. vl
LIST OF TABLES 0 . 0 0 0 0 0 o ป . . o , 0 . . . o o , o vii
I CONCLUSIONS o . o o o o o o o o . o o . . o o * o o . . , o o o . 1
H RECOMMENDATIONS . ป . . , , ป . o o o . ป . o ., , ป o o 3
IE INTRODUCTION 5
A. Statement of Problem . . . . o . . . . . 5
Bo Objectives 0 . 0 , 0 0 .,,,,,, a .. 0 ..,, 00 6
Co Technical Approach and System Description ........ 6
Do Program Plan . . . . o . . . . . . o . o . o . . . 10
IV SYSTEM DEVELOPMENT . 0 . . ป o ป ป o ซ . o o o , ป o 13
A0 Summary . 13
Bo Vessel Selection . . . . . . o . . . . . . . o o . . o . 15
Co Hardware Development o 17
V RESULTS AND ANALYSIS ,......,.,.,.,...,, 39
A. Summary - Biochemical Performance o . . o . . o o 39
B. Discussion - Biochemical Performance . 50
C. Evaluation - Mechanical/Electrical Performance o 65
D. Analysis - Economic o 59
VI ACKNOWLEDGEMENTS ......,.........,. 75
VII REFERENCES . o o o 0 o o o 0 . o . . . o . o , o o . ซ . . ป . o o . 77
VIII GLOSSARY . . 0 0 o ป o ป o o o . o ป . 0 . ป 0 . ป ป o . . ป ป 79
IX APPENDICES 81
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LIST OF ILLUSTRATIONS
Figure Page
1 Watercraft Waste Treatment System Schematic 8
2 U. S. Army Corps of Engineers Dredge Gerig 16
3 Waste Water Treatment System Installation 18
4 Waste Water Treatment System, Shipyard Installation,
Tampa, Fla. . 19
5 Waste Water Treatment System, Shipyard Installation,
Tampa, Fla 20
6 Waste Water Hydrograph for Dredge Gerig, August 1969 .... 21
7 Pump-Grinder . 23
8 Fe++ vs. Current per Gallon per Minute 26
9 Electrocoagulation Cell, Internal and External Views 26
10 Electrocoagulation Cell Vent Schematic 27
11 Hydrogen Gas Evolved vs. Applied Current 27
12 Upflow Clarifier and Concentrator 28
13 Upflow Clarifier on Motion Simulator 30
14 Gerig Incinerator Installation 34
15 Gerig Incinerator Installation . 0 35
16 Gerig Type Incinerator Installed on 7500 Gal/Day System . . . . 36
17 Typical Gerig Hydrograph During Sea Trials 40
18 Effects of KMnO4 on BOD5 Due to Seed Poisoning 58
19 Projected Annual Cost of System Operation 71
20 Comparative Cost of Treatment vs. Holding 74
VI
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LIST OF TABLES
Table Page
1 Watercraft Waste Treatment System Operating and Design
Parameters 9
2 Gerig Ports During Watercraft Waste Treatment System
Sea Trials 14
3 Summary Influent Waste Characteristics, Dredge Gerig,
August 1969 . 21
4 Electrocoagulation Cell Specifications 25
5 Waste Treatment Clarifier Performance Results 29
6 Gerig Incinerator Ash Analysis 33
7 Daily Shipboard Waste Treatment System Water Analysis
Averages 41
8 On-Board Instrumentation 46
9 Effects of Chemicals in Gerig Inventory on Glucose/Glutamic
Acid BOD . . 52
10 Effect of Aeration on BOD5 Reduction in Gerig Effluent 54
11 Effects of Potassium Permanganate on System Effluent BOD5 . . 55
12 System Effluent Treated with KMnO4 at 37ฐC for 60
Minutes Then Neutralized with Sodium Thiosulfate 56
13 Effect of Ozone on BOD5 Reduction in Gerig Effluent 56
14 Effect of Hydrogen Perixide on BOD5 Reduction in Gerig
Effluent 57
15 Results of Granular Carbon Column Test 59
16 Results of Full Scale Carbon Column Operation 60
17 Comparison of Two-Day and Five Day BOD Data 64
18 Waste Treatment System Fixed Costs 72
19 Waste Treatment System Operating Costs 73
VII
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SECTION I
CONCLUSIONS
1. As a result of the Watercraft Waste Treatment System Development Pro-
gram a practical and economically viable electro-chemical treatment
system has been demonstrated.
2. The system meets or exceeds the effluent water quality standards proposed
by the Environmental Protection Agency on May 12, 1971 (Federal Register,
Volume 36, No. 92).
Proposed Standard Demonstration Result
Coliform bacteria less than Essentially zero colonies
240 MPN CoL /100 ml
Biochemical Oxygen Demand Less Than
100 mg/1 Average 94 mg/1
Suspended Solids Less Than 150 mg/1 Average 49 mg/1
3. Water treatment by products, such as sludge, can be safely and econ-
omically incinerated on board ship.
4. Shipboard sewage (culinary, sanitary and laundry wastes) contain signi-
ficantly higher Biochemical Oxygen Demand and suspended solids than
commonly encountered in municipal waste. A factor of two or three for
Biochemical Oxygen Demand and Suspended Solids over municipal wastes
should be utilized for system design. The ratio of dissolved Biochemical
Oxygen Demand to total Biochemical Oxygen Demand is significantly
higher for shipboard wastes than municipal wastes.
5. Enforcement of water quality standards and other State and Federal Regula-
tions will result in increased sewage Biochemical Oxygen Demand and
suspended solids on board ship as housekeeping habits are improved.
6. Present techniques for on-shore evaluation of treatment plants are of
limited value due to the difficulty in accurately reproducing hydraulic,
chemical and biological loading of a system.
7. Biochemical analysis of shipboard wastes is highly sensitive to technique;
the wastes are significantly different from those of a municipal nature.
The Standard Methods must be rigorously adhered to. Erroneous
technique for Biochemical Oxygen Demand determination will usually
result in analytical results indicating lower than actual values and mis-
lead performance evaluation.
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SECTION n
RE COMME NDATIONS
1. Continue system development for elimination of other shipboard wastes
such as bilge water, wet garbage and dry combustibles. The system
has unique potential for handling these wastes with minor modifications.
2. Continue evaluation of means for removal of dissolved Biochemical Oxygen
Demand for the purpose of improving operating economics.
3o Increase system reliability by elimination of the solids concentrator
and increasing the size of the upflow clarifler.
4. Increase system capacity by development of a reliable, inexpensive, sludge
level detector.
5. Develop a rigorous certification program for shipboard waste treatment
systems. Land-based demonstration should be accompanied by a care-
fully programmed simulation of shipboard sewage loading.
6. Develop a certification program for analysis of shipboard effluents thus
insuring an equitable comparison of competitive treatment systems.
7. The burden on shipboard waste treatment facilities may be reduced by
minimizing hydraulic loading (careful adjustment of heads and other water
sources) and providing convenient receptacles for paints, solvents, de-
sealers and other chemicals commonly used on board ship.
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SECTION in
INTRODUCTION
A. Statement of Problem
The Report of the Department of the Interior, FWPCA, to the 90th Congress
entitled, 'Wastes from Watercraft" contains a compelling assessment of the
magnitude of water pollution of the Nation's waterways. In view of the Nation's
new resolve to restore and enhance the quality of our water, it was stated that
vessel discharges could not be ignored. It made little sense to expect cities
and industries to clean up discharges only to have the water remain polluted by
discharges from vessels. Harbors, bays, lakes, estuaries, and other heavily
navigated waters differ in their physical and hydrological characteristics and
also from the pollution control standpoint. Because of differences in assimil-
ation capacity, vessel pollution may assume critical proportions in some areas.
Prior to the start of the program described herein there was considerable doubt
among the marine engineering and naval architectural communities about the
feasibility and practicality of on-board treatment of water craft wastes. The
lack of availability of suitable on-board treatment facilities left the marine
engineer with only one choice for disposal of wastes; on-board storage with
subsequent discharge on shore or at sea. On-board storage is a simple solu-
tion in some cases but raises manifold problems in many others. Primary
are the problems of adequate space on board ship for storage and the lack of
suitable shore facilities for transfer and treatment of watercraft wastes. In
the case of ships operating from small ports, many municipalities have found
themselves incapable of handling the ship wastes; the wastes being equivalent
to the total daily treatment capacity of a small community.
Many of the problems associated with on-board treatment versus holding are
intangible and particularly difficult to assess economically. Such factors as
vessel delays in port, inconveniences associated with waste transfer, and the
need for additional personnel are worth money, but how much? Complete in-
dependence from shore is obviously desirable and circumvents many of the in-
tangibles. This was the prime motivator behind the work achieved in this
program.
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B. Objectives
The objectives of the watercraft waste treatment program were:
1. Develop a prototype shipboard waste treatment system.
2. Demonstrate ability of the shipboard waste treatment system to pro-
duce effluent of secondary water quality standard during sea trials
on board a representative vessel.
3. Demonstrate feasibility of incineration of sludge produced by the plant
thereby demonstrating proper treatment and disposal of all plant
effluents.
4. Evaluate the economic viability of the system developed.
C. Technical Approach and System Description
The method chosen for treatment of shipboard wastes was electrochemical in
nature as contrasted to the more classical biological techniques commonly used
for land-based treatment of municipal wastes. This choice was based on the
following factors which were later demonstrated to be essentially correct.
1. Electrochemical treatment, which does not rely on formation of a
stable bio-mass for sewage processing, is less vulnerable to hydraulic
and chemical shock loads which are likely to occur on a ship. Ability
to process with variable salinity of the carrier water is particularly
important.
2. Electrochemical treatment facilities are inherently smaller and of
less weight, due to shorter sewaage processing times, than equivalent
biological treatment facilities. These characteristics are desirable
due to limited space and weight available on shipboard.
So Electrochemical treatment processes lend themselves readily to auto-
mation thus precluding the requirement for specially trained personnel
on board ship for maintenance of the treatment facility.
4. Electrochemical treatment processes can be rapidly started and stopped.
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The process selected for development and demonstration involves six discrete
steps:
1. Comminution of solids for ease of transport and further treatment.
2o Electrocoagulation of sewage for ease of removal of suspended solids.
3. Solids separation.
4o Soluble BOD reduction.
5. Coliform bacteria removal.
6. Incineration of solids.
To implement the process steps delineated in the technical approach, a system
as shown in Figure 1 and described in Table 1 was developed. A description of
the system inclusive of key operating principles is included herein because of
the extent of wholly contractor-developed hardware involved.
The treatment plant is located at a suitable deck location for collection of the
combined wastes generated aboard the ship. The total wastewaters of sanitary,
culinary, laundry and wash origin are collected in the receiving tank of the pump-
grinder, the primary functions of which are comminution of solids and establish-
ment of the process flow rates. Sufficient volume is incorporated in the receiv-
ing tank to optimize system processing duty cycles.
The solids content of the waste water is comminuted by the grinder to particles
of cross section not exceeding 0. 25 inch diameter. The resulting slurry is
pumped at a rate of 5 gallons per minute to the electrocoagulation cell for
coagulation. Electrical generation of the coagulating agent by applying direct-
current voltage to iron containing plates was employed. Iron was selected over
aluminum as the expendable metal ion source because of superior settling
characteristics of the agglomerated iron flocculent particles.
Flocculation of the "micro floe" formed within the electrocoagulation cell is
accomplished by rotating motion enhanced by addition of sodium aluminate as a
flocculant aid. The mixing is an initial function within the downcomer section of
the upflow clarifler. Subsequent detention at a suitable rate of flow upwards
through the clarifier permits the formation of a layer of sludge (sludge blanket)
comprised of the flocculated sewage solids. The clarified water overflows a
weir at the top of the clarifier. Unlimited growth of the sludge blanket is pre-
cluded by programmed sludge withdrawal from the blanket. Maintenance of
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VENT
VENT OVERBOARD ซ -r-l
AIR
INFLUENT SEWAGEH
oo
L.
FUEL IN
OVERBOARD DRAIN
EFFLUENT
OVERBOARD
1. Pump Grinder 11.
2. Relief Valve 12.
3. Blower and Venturi 13.
4. Electrocoagulation Cell 14.
5. Flocculant Aid Storage 15.
6. Hypochlorite Storage 16.
7. Hypochlorite Pump 17.
8. Flocculant Aid Pump 18.
9. Upflow Clarifier and Concentrator 19.
10. Sludge Recycle Pump 20.
Effluent Holding Tank
Sludge Storage Tank
Sludge Withdrawal Pump
Foam Extractor
Foam Recycle Pump
Emergency Drain Pump
Effluent Aeration Tank
Chlorination Tank
Carbon Columns
Effluent Recycle Pump
21. Sludge Transfer Pump
22. Sludge Day Tank
23. Sludge Pump
24. Incinerator
25. Overboard Discharge Pump
Figure 1. Watercraft Waste Treatment System Schematic
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TABLE 1. WATERCRAFT WASTE TREATMENT SYSTEM OPERATING AND
DESIGN PARAMETERS
Volumes
Pump Grinder Receiving Tank
Upflow CLarifier
Chlorination Tank
Sludge Concentrator
Sludge Holding Tank
Floe Aid Storage
Hypochlorite Storage
Electrocoagulation Cell
Carbon Columns
Aeration Tank
Flows
Pump Grinder
Clarifier Recycle
Sludge Withdrawal
Sludge Recycle
Sludge Transfer
Overboard Discharge
Emergency Drain Pump
Floe Aid
Hypochlorite
Carbon Column
Incinerator Feed
150 gallons
300 gallons
100 gallons
110 gallons
100 gallons
30 gallons
30 gallons
10 gallons
30 gallons ea. (4)
(70 Ibs. carbon ea.)
30 gallons
5 gpm
4 gpm
3 gpm
11 gpm
11 gpm
8 gpm
53 gpm
12 ml/min
7ml/min
4. 6 gpm
.33 gpm
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high quality effluent is assured when the sludge solids content falls within the
limits determined by a balance of influent and effluent solids. The withdrawn
sludge is stored within a holding tank for disposal by incineration.
The incinerator is specially designed to incinerate "wet" sludge to yield inert
ash and harmless gaseous effluents.
Soluble BOD is removed from the clarifier effluent by passing the effluent
through continuously aerated activated carbon columns. Continuous aeration
is assured by aerating column effluent and recycling it through the columns
when no upflow clarifier effluent is available. The effluent is disinfected by
chlorination for discharge overboard.
Two auxiliary functions contributing to effective and safe operation are per-
formed by the hydrogen vent blower and foam extractor. Hydrogen generated
by electrolysis of the waste water is safely diluted and discharged by the vent
blower. Foam which is generated in sizeable quantities when treating sanitary
wastes is removed by the foam extractor for incineration. The solids yield
from foam extraction is significant.
D. Program Plan
Contract 14-12-522 entitled Treatment of Watercraft Wastes was awarded
January 1969 and work was initiated May 1969. The contract was divided into
two phases. The key objective of Phase I was a laboratory demonstration of a
system to treat combined vessel wastewaters to secondary water quality stan-
dards, while the key objective of Phase n was a demonstration of this equip-
ment aboard a representative vessel for an extended period.
A Program plan was prepared which included the following tasks during Phase I:
1. Component design, development and test; stressing electrocoagulation
and solids separation.
2. Selection of suitable ship for Phase II demonstration.
3ซ Survey of wastewater characteristics aboard the selected ship.
4, Motion simulation test of motion sensitive components.
5. Design of controls, power supply, sensors, pumps and tanks to in-
corporate development components into the treatment system.
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6. Test system in a shore-based laboratory.
7. Refurbish for installation in demonstration ship.
Phase II, included the following tasks:
1. Installation of the system aboard the ship,
2o Demonstration of the system aboard ship.
3, Extensive laboratory analysis during sea trials.
4o Installation of sludge incinerator.
5. Economic analysis.
6. Final report.
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SECTION IV
SYSTEM DEVELOPMENT
A. Summary
The waste treatment system developed for this program was evolved from the
basic technology of electrocoagulation in early 1969 through development of the
essential elements necessary for automated processing of sewage on board a
ship. The selection of the test vessel, the Gerig, in July of 1969 and subsequent
survey of the vessel's hydraulic and biochemical loading permitted final sizing
and design of the shipboard developmental system. Key portions of the system
were then evaluated in the laboratory at the subsystem level prior to assembly
and test as a complete system. During the spring and summer of 1970, the
completed system was evaluated in the laboratory utilizing sanitary sewage pro-
duced by a large office building augmented by various mixtures of simulated
sewage, culinary wastes, and actual wastes obtained from the U.S. Coast Guard
Cutter Sassafras.
In August 1970 the system was prepared for shipment to the Gerig. The system,
at this time, did not include a sludge incinerator. When the program was in-
itiated it was thought that an incinerator suitable for shipboard use could be
procured on the market and, as a consequence, did not require demonstration
during this program. Subsequent evaluation of some 70 incinerator manufacturers
in the United States indicated that a small, light weight, automatic incinerator
suitable for shipboard use was available from only one vendor. An early and
much used model of this incinerator was obtained for evaluation in May 1970,
This incinerator was found to be incompatible with the prototype system.
Because disposal of sludge is a necessary adjunct to sewage treatment and an
incinerator can be utilized for other wastes on board ships, General Electric
developed an advanced incinerator design for inclusion in the demonstration
program. This incinerator was installed on the Gerig in January 1971.
The waste treatment system was installed on the Gerig during the period of
Sept. 1970 to Oct. 1970. Systems tests commenced Dec, 16, 1970. Some
limited performance data had been obtained in late October while the Gerig was
in dry dock and the vessel was hooked up to a fresh water supply.
During the sea trials the Gerig operated from a number of ports, listed in
Table 2, on the Gulf and Atlantic coasts until August 1971. The operation of the
system during sea trials is covered in detail in Sections IV and V.
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Operation on board the Gerig offered a unique opportunity for thorough evaluation
of shipboard waste treatment problems. The various ports of operation provided
background water of varying salinity, temperature, dissolved oxygen content, and
solids concentration; in fact some of this water was badly polluted. The ship pro-
vided a ship-to-shore launch twice a day as part of its normal routine thereby
facilitating transport of fresh samples to laboratories for biochemical analysis.
During part of the sea trials, an Environmental Protection Agency mobile water
analysis laboratory was based at the dock for immediate analysis of water samples.
TABLE 2. GEEIG POETS DUEING WATEECEAFT WASTE TEEATMENT
SYSTEM SEA TRIALS
Place
Date
Tampa, Florida (Dry Dock)
Pascagoula, Mississippi
Gulf Port, Mississippi
Pensacola, Florida
In Transit
Port Canaveral, Florida
Savannah, Georgia
Brunswick, Georgia
In Transit
Boca Grande, Florida
In Transit
Wilmington, North Carolina
Moorehead City, North Carolina
September 1970 to December 18, 1970
December 19, 1970 to January 1, 1971
January 2, 1971 to January 14, 1971
January 15, 1971 to January 23, 1971
January 24, 1971 to January 25, 1971
January 26, 1971 to February 9, 1971
February 9, 1971 to March 10, 1971
March 11, to April 10, 1971
April 11, 1971 to April 13, 1971
April 14, 1971 to April 21, 1971
April 22, 1971 to April 24, 1971
April 25, 1971 to July 2, 1971
July 3, 1971 to August 9, 1971
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In July and August 1971, General Electric provided shore laboratory facilities
within a few miles of the dock. When the ship was at a port for short periods,
certified commercial laboratories were utilized.
B. Vessel Selection
Vessel selection for the demonstration of the watercraft waste treatment was
the result of a cooperative effort involving the Environmental Protection Agency,
the Army Corps of Engineers, the Coast Guard, and the General Electric
Company. Selection required a trade-off study considering geographic area of
operation, crew size, operating schedule, existing sewage plumbing, and avail-
ability for modification.
Utilization of a Coast Guard vessel was eliminated early in the trade-off as
Coast Guard activities result in an unpredictable operating schedule which would
adversely affect test sample collection.
Review of U. S. Army Corps of Engineers Hopper Dredges serving the East
Coast indicated that the Dredges Gerig and Goethals would be acceptable choices.
Both vessels operate in reasonable proximity to the Philadelphia area, crew
size to be served by the waste treatment system (about 50 men) is ideal, and
the operating schedules are predictable.
The Gerig, shown in Figure 2, was selected for sea trials. Operations of the
Gerig are typical of an ocean going vessel; activities are conducted 24 hours a
day, seven says a week. The Gerig is continually under way with substantial
operating time spent several miles off shore. The Gerig dredging schedule
results in exposure to different background water conditions associated with the
various ports and at sea conditions during transit time of several days duration.
The Gerig was therefore both a convenient test bed and is typical of vessels for
which the watercraft waste treatment system was developed.
The design work necessary for the installation of the waste treatment system was
accomplished in conjunction with the U. S. Army Corps of Engineers Marine De-
sign Division located in Philadelphia.
The waste treatment system was installed on the Gerig during October 1971 at
the Tampa Shipyard. The unit was installed on the aft lower deck on the port
side in the crew's locker room. The unit was plumbed in parallel with an ex-
isting treatment system. The plumbing was arranged to allow flow of sanitary,
shower, galley, and laundry waste to the system. The general arrangement is
defined on Corps of Engineers, Philadelphia, office drawing 1-10-104. The
incinerator was installed on the top boat deck.
15
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Figure 2. U.S. Army Corps of Engineers Dredge Gerig
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In the system installation, as shown in Figures 3, 4, and 5, the waste water of
culinary, laundry and sanitary origin was collected from the crew quarters in
the aft portion of the vessel. The galley, which serves the entire crew, and the
officer's lounge is located in the aft portion of the ship. Laundry waste was col-
lected from two washing machines. The shower waste was collected from 10
showers, one bath tub and 43 sinks. Sanitary waste was collected from 13
toilets.
The crew operates three shifts a day, seven days a week with meal times
scheduled 0715 to 0815, 1120 to 1220, and 1710 to 1810 hours. The vessel
docks every second Thursday for repairs and supply.
An additional advantage was gained with the Gerig as it is one of three vessels
studied and reported in an Environmental Protection Agency report entitled
"Extended Aeration Sewage Treatment Plants on U. S. Corps of Engineers
Dredges" by B. Sacks (Ref. 1).
A survey of the wastes produced on board the Gerig was conducted in August
1969 and is reported, in detail, in Reference 2. A summary hydrographic
profile, as shown in Figure 6, was established and used for final si/ing of the
waste treatment plant. Nominal daily flow was 2500 gal/day. Summary influent
biochemical characteristics are shown in Table 3. These wastes comprised
the total sanitary, laundry, and culinary wastes from the aft section of the
Gerig.
C= Hardware Development
The laboratory development of the watercraft waste treatment system was
reported in detail in the Phase I report entitled Component Development Report
for Watercraft Waste Treatment System. This report is included, in its
entirety, in Appendix A and covers the development, analytical and design
activities conducted in the General Electric facilities in Philadelphia, Pa. from
May 1969 until shipment of the system to the Gerig in August 1969.
To facilitate the discussion of waste treatment system performance, which
follows in Section V, a discussion of how the hardware in the system was
evolved is presented covering both laboratory development and later modifica-
tions during sea trials.
It was recognized at the inception of the program that full exploitation of the
advantages of a watercraft waste treatment system utilizing electrocoagulation
would require development of apparatus for comminution, solids separation,
and further refinement of electrocoagulation technology. Absence of off-the-
shelf components compatible with the practical goals of shipboard operation,
17
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INCINERATOR
HOUSE
TOP BOAT DECK
WASTE TREATMENT
SYSTEM
LOWER DECK
oo
GERIG
CREW
LENGTH
BEAM
DRAFT
DISPLACEMENT
Commissioned 1947
19 officers and 78 men
351 feet 9 inches
60 feet
24 feet 4 inches loaded
8970 long tons loaded
Figure 3. Waste Water-Treatment System Installation
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Figured. Waste Water Treatment System, Shipyard Installation Tampa, Florida
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to
o
Figure 5. Waste Water Treatment System, Shipyard Installation Tampa, Florida
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a
u>
O
a:
UJ
SANITARY, GALLEY, AND LAUNDRY
WASTES FOR 50 MEN
2400 0200 0400 0600 0800 10QO 1200 1400 1600 1800 2000 2200 2400
TIME, hours
Figure 6. Wastewater Hydrograph for Dredge Gerig, August 1969
TABLE 3. SUMMARY INFLUENT WASTE CHARACTERISTICS,
DREDGE GERIG, AUGUST 1969
Parameter
Average
Range
Flow
Total Oxygen Demand, ppm
Biochemical Oxygen Demand, ppm
Total Suspended Solids, ppm
Total Volatile Suspended Solids, ppm
pH
Conductivity jU mhos/cm
2500 gal/day
890
650
600
450
21000
0-8.9 gal/min
175-2300
175-880
125-1400
90-1200
6.9-8.5
9000-38000
21
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suitable capacity, minimum cost, size and complexity dictated that develop-
ment emphasize these three functional components.
Comminution
To permit pumping of combined sewage through minimum diameter piping, and
optimize the electrocoagulation unit internal geometry for optimum scouring
velocities and power requirements, a limitation upon maximum particle size
was established.
To accomplish the design of a unit combining the sewage storage, comminuting,
and pumping functions an adaptation was made of a comminution apparatus
developed by General Electric for the Combined Sewers Separation Project
under the auspices of the American Society of Civil Engineers, as reported in
Reference 3. The household pump-storage-grinder development had as an
objective solids comminution to a particle size not exceeding 0. 25 diameter.
The comminuted sewage facilitated transport by pumping through piping much
reduced in diameter from conventional sanitary pipe. A detailed discussion of
the alterations made, including establishment of pump rate and storage volume,
may be found in Appendix A.
The unit referred to as pump-grinder consists of a double ended a-c motor
which directly drives a speciaUy adapted Hotpoint ฎ commercial grinder
through a belt driven Moyno Qy pump. The pump-grinder, shown in Figure 7,
was installed in a 150 gallon tank to a depth within two inches of the tank bottom.
This clearance, which is accessible from a special access port, allows volume
for metallic objects to settle out harmlessly.
The pump-grinder has the versatility of being remotely located from the re-
mainder of the system; in fact, more than one pump grinder, with a suitable
holding tank, may be remotely located from the treatment plant serving as a
collection point for sewage to be treated. This concept has been demonstrated
on a Great Lakes ore carrier where the treatment plant is located in the engine
room and the wastes from the deck crew, located in the bow 600 feet away, are
collected and pressure transported under pressure through a one and one-half
inch diameter pipe.
Electrocoagulation
The primary function of the electrocoagulation cell is to electrically generate
the ferrous hydroxide coagulant in the presence of sewage solids. This is ac-
complished by arranging mild steel plates in a parallel matrix within a housing
22
-------
Figure 7. Pump-Grinder
-------
such that all waste water flow must traverse the spaces between plates.
Alternate plates are energized with a d-c voltage which is controlled to
maintain a prescribed current level. The reactions which occur include the
release of ferrous ions from the anodes and the electrolysis of the waste water
flowing in the plate spaces.
The detailed design activities and biochemical performance testing performed
on various configurations of the electrocoagulation cell are reported in
Appendix A. The configuration developed for incorporation in the demonstra-
tion system is described in Table 4.
It was determined in test that effective coagulation of the waste required a
minimum of 50 mg/liter of ferrous ion. Figure 8 presents the measured iron
in the effluent for various operating flows and currents, the current to flow
ratio was established as 35 amp/gpm. For a pump-grinder rate of 5 gpm, the
constant current required of the power supply was 175 amperes.
The electrocoagulation cell, depicted in Figure 9, is a wholly sealed unit. To
vent hydrogen and remove foam generated in the sealed cell, the venting circuit
shown in Figure 10 was developed. This venting arrangement was reviewed
and approved by the Coast Guard and subsequently proved to be completely suc-
cessful. The blower flowrate was established at 200 scfm at 1.1 in. H^O
pressure loss (the limitation on pressure loss in the vent stack to the upper
boat deck). The evolution rate of hydrogen at 175 amperes is shown in Figure
11. The selected values yield a dilution ratio of air to hydrogen by volume of
5300:1, well below the four percent lower explosive limit.
Operation of the electrocoagulation cell in brackish water, as would be the case
with the Dredge Gerig, requires the addition of hydroxyl ions to elevate the
natural pH of the electrocoagulation cell effluent from the range 6 to 7 to
greater than pH 9 for optimum flocculation. The flocculant aid selected from
combined tests with the upflow clarifier was sodium aluminate.
Solids Separation
To assure clarity of the system discharge, a method to separate the solids
coagulated in the electrocoagulation cell is required. Off the shelf centrifuges
and cyclones evaluated did not meet the practical objectives of suitable capacity,
moderate cost, automatic solids discharge, and reliability.
24
-------
TABLE 4. ELECTROCOAGULATION CELL SPECIFICATIONS
Housing material
No. of plates
Plates thickness
Plate Material
Total area of plates
Estimated plate life
Volume of cell
Flow volume
Wt. of iron
Hydraulic radius
Reynolds No.
Flow rate
Current
Current density
Scrubbing air jets
Air Pressure
Jet Nozzle diameter
Epoxy - Fiberglas ^
16
0.25 in.
Steel, type 4130, cold rolled
51.3 ft2
600 hrs
1. 85 ft3
1. 3 ft3
271 Ibs
0.47 in
8440
5 gpm
175 amperes
6.8 amp/ft2
19
5 psig
0.125 in.
25
-------
90 r
80
1
V)
oc
oc
111
LL
:- 60
20
OP.PT.
0 10 20 30 40 50 60
CURRENT/FLOWRATE, amps/gpm
_i I
Figure 8. Fe vs. Current per Gallon per Minute
Figure 9. Electrocoagulation Cell, Internal and External Views
26
-------
VENT DUCT
BLOWER
1
/
^>-
i
MAKEUP AIR
\
\
200 SCFM
HYDROGEN
SLUDGE STORAGE TANK
ELECTROCOAGULATION
CELL
RECYCLE PUMP
Figure 10. Electrocoagulation Cell Vent Schematic
.05
.04
"5
E
.02
.01
OP. PT.
100
CURRENT, amp
200
Figure 11. Hydrogen Gas Evolved vs. Applied Current
27
-------
A concept which resulted in a means of solids separation in a short time period
and in a compact volume is upflow clarification. The mode of operation of the
upflow clarifier (see Figure 12) is to encourage the coagulation of solids by
gentle agitation in a downcomer to facilitate formation of a sludge blanket,
through which subsequent flow passes. The sludge blanket serves as a filter
for suspended solids and possibly an adsorber of dissolved BOD. The dis-
charge liquor is of high clarity (less than 50 ppm total suspended solids) when
the clarifier flow rate and sludge settling rate are maintained in equilibrium.
CLARIFIER .
SLUDGE RECYCLE
PUMP
24 GPH
SLUDGE WITHDRAWAL
PUMP
A =11.47 ftZ
^
A = 0.59 ft2
V^ = .113 ft/min.
V2 = .058 ft/min
Figure 12. Upflow Clarifier and Concentrator
It was established in development test that maintenance of the fluid-solids
equilibrium under shipboard conditions of flow and influent solids loading
required a stage wherein sludge was concentrated. Solids balance could, of
course, be maintained by simply removing from the clarifier large quantities
of the predominantly liquid sludge. There is a high economic premium upon
the quality of sludge withdrawn, because ultimate disposal of this sludge is by
incineration. Since one to two percent total suspended solids content for sludge
28
-------
is a common value for municipal treatment long term settling basins, this
became the target concentration value for this apparatus. Rapid concentration
of sludge was achieved by adding a second stage concentrator - adding 20 per-
cent volume to the component for a ten fold compaction. Precedent for two
stage clarification, in an application where sludge quantities were critical, is
contained in Reference 4.
The physical configuration of the demonstration upflow clarifier is shown in
Figure 12,, The withdrawal of sludge from the blanket in the clarifier to the
concentrator occurs continuously while the concentrator effluent is returned
to the clarifier inlet. The concentrator sludge, which ranges from one to two
percent total suspended solids (See Table 5), was scheduled for withdrawal by
pump each 15 minutes of system operation. Conditions were established by
average influent solids loading and daily hydraulic loading obtained from the
Gerig Survey, Reference 2.
TABLE 5. WASTE TREATMENT CLARIFIER
PERFORMANCE RESULTS
Run
Clarifier
flowrate (gpm)
Flocculant
aid rate (ppm)
Test
duration (min)
Agitator
speed (rpm)
Sample
time (min)
Clarifier
influent
TSS (ppm)
Clarifier
influent
BOD (ppm)
Clarifier
effluent
TSS (ppm)
Clarifier
effluent
BOD (ppm)
Concentrator*
sludge TSS
(ppm)
Clarifier
influent
Turb (JTU)
Clarifier
effluent
Turb (JTU)
11
5
50
sodium aluminate
120
54
60 90 120
836 680
26 - <-20
12492 9348 11868
12
5
50 sodium
aluminate
120
54
60 120
828 552
396
50 34
99
13
5
100
sodium aluminate
270
120
60 120 180 240 270
1000 824 716 400 484
408 390
34 22 40
145 113
12470 11870
90 130 100 90
24 16 18 24
14
5
100 sodium
aluminate
180
150
60 180
872 672
68 58
26358
125 125
28 28
15
5
100
sodium aluminate
216
150
60 174 216
856 436
108 58
20594
130 70
30 17
16
5
100 sodium
aluminate
132
150
60 132
752 356
52 28
19987
110 115
30 24
Obtained by pump withdrawal at 2 gpm.
29
-------
It can be readily appreciated that ship's motion might affect such a clarifier if
accommodation for sea states is not made. The development of Upflow Clarifier
as reported in Appendix A focused upon establishment of a maximum over-
flow rate achievable (minimum component volume results) and upon minimiz-
ing of external influences upon performance. The demonstration upflow clarifier
is shown in Figure 13 while mounted on the motion simulator test apparatus for
the purpose of verifying performance at sea state conditions.
AT +20 DEC
Figure 13. Upflow-Clarifier on Motion Simulator
30
-------
Solids Disposal
Solids disposal was accomplished by incineration. Initial consideration was
given to storage of the separated solids with subsequent dumping either at sea
or at the dock. However, the tank size required to support the 14 day cycle of
the Gerig between dockings, with the possibility of no sea dump, was excessive.
A continuous means of solids disposal was therefore necessary and was ac-
complished by incineration.
A prototype, electric, home size incinerator, developed by the General Electric
Advanced Environmental and Pollution Control Laboratory and field tested for
over a year, had been used successfully to dewater and burn waste sludge.
Additionally an incinerator developed for the U. S. Navy was provided by U. S.
Naval Engineering Center at Annapolis. Evaluation of these units indicated
that sludge incineration is a viable concept, but the units were incapable of
operating at the rates of sludge expected from the system. Further, it was
determined from the literature that a minimum combustion temperature of
1500ฐF was required to completely burn the organics present in the sludge in
order to insure a completely odor-free exhaust. It was therefore necessary to
develop an incinerator matched to the specific requirements of the waste treat-
ment system. The incinerator supplied in this program was developed entirely
with General Electric funds.
The incinerator requirements were determined by the needs of a somewhat
larger waste treatment system being developed for U. S. Navy requirements.
The resulting incinerator has a capacity of 4000 pounds per day of liquefied
sludge consisting of 90 to 100 percent liquid and 0 to 10 percent solids by weight.
The liquid content can contain a high percentage of sea water with 1. 5 percent
average suspended solids content. Incineration products were a clear, odor-
free, exhaust gas and a sterile ash containing essentially no residual organics.
The incinerator system to meet these requirements consists of a commercial
burner unit fired with diesel oil, an air cooled, vortex type, combustion
chamber with tangentially injected flame, and a motor driven fan and fuel pump
with associated controls and safety interlocks. The sludge is atomized and
entrained in the vortex until complete combustion is achieved thus eliminating
the need for grates or screens which require frequent cleaning. The assembled
system occupies a volume six feet long by five feet wide by four feet high, ex-
clusive of stack and fuel tank, and weighs less than 1500 pounds.
31
-------
The incinerator nominally operates at 500, 000 Btu's per hour burner output
with less than 0. 5 pounds of fuel per minute and a sludge rate of 0, 33 gallons
per minute. Normal operating time of this incinerator on the Gerig was six
to eight hours per day. The excess capacity of this incinerator could easily
be used for disposal of bilge water and addition of a second, modified, nozzle
would permit combustion of wet garbage or suitably prepared dry combustible
wastes such as paper.
Ash removal was required every one to two weeks. Analysis of the ash re-
vealed less than one percent organics (volatile solids) and the remainder prim-
arily salt. An ash analysis is shown in Table 6. Figures 14 and 15 show the
incinerator as installed on the Gerig. Figure 16 shows the incinerator installed
as a integral part of a larger treatment plant.
Sea Trial Developments
During the initial test period, from Oct., 1970 to Dec. , 1971, it was noted that
the sludge blanket periodically overflowed the upflow clarifier weir during ex-
tended operation indicating a hydrodynamically unstable condition. A check of
the system influent flows revealed rates of 3000 to 5000 gpd. A survey of the
ship revealed that the flushometer rates on the toilets were set above specified
limits. After adjustment of the flushometers, the daily flows were 2000-2500
gpd and the upflow clarifier appeared to stabilize.
During operation at Pascagoula/Gulfport, through January 14, 1971, it was
observed that the sludge blanket once more passed over the weir resulting in
high solids content in the effluent even though the system flow rate was within
the design limit. These observations led to the conclusion that the system did
not have sufficient solids storage capacity in the upflow clarifier and 50 gallon
sludge concentrator. The 50 gallon solids concentrator was replaced with a
110 gallon concentrator. Solids carry-over was no longer observed during
normal operation.
As a result of the increased concentrator size, the system became more
sensitive to the development of anaerobic growth conditions due to the longer
dwell time of sludge in the system. This was observed on several occasions
while dredging at Port Canaveral, Florida in January 1971 and presisted until
operations in Brunswick, Georgia in April 1971. In these locations, the back-
ground water was frequently reducing, as evidenced by positive oxygen re-
duction potential and low dissolved oxygen. Accumulations of hydrogen sulfi.de
and methane gas were frequently disturbed during dredging operations. It was
felt that a combination of the quality of the background sanitary water and an
unusually low duty cycle accelerated the development of anaerobiosis. The
problem was isolated after a rigorous water analysis period in Brunswick, Gaป
with the Environmental Protection Agency water quality mobile laboratory and
utilization of the on board water quality monitor.
32
-------
TABLE 6. GERIG INCINERATOR ASH ANALYSIS
Ash Constituent*
Percent by Weight
Volatiles at 600ฐC
Sodium
Chloride
Magnesium
Sulfate
Calcium
Iron
Silica
Phosphate
Fluoride
Zinc
Manganese, Copper
Cadmim, Silver, Nickel
0.6%
38.0
28.0
6.0
9.0
0.1
0.6
0.1
0.7
0.1
0.01
Trace
No detection
*Sample from Feb. 21, 1971, Savannah, Ga.
In order to prevent anaerobic growth, a chlorinated recycle mode of operation
was initiated at Boca Grande, Florida in April 1971. Fluid from the clarifier
was continuously pumped into the concentrator while chlorine (12 ml/min,,) was
added to the concentrator effluent which was returned to the downcomer. This
had the effect of maintaining an oxidizing environment in the clarifier/con-
centrator network and prevented the formation of anaerobic growth anywhere in
the system.
33
-------
Figure 14. Gerig Incinerator Installation
34
-------
Figure 15. Gerig Incinerator Installation
-------
Figure 16 Gerig Type Incinerator Installed on 7500 Gal/Day System
-------
During subsequent testing, the system duty cycle decreased due to a decrease
in total influent flow (1200-1600 gpd) due to crew shore leave. This allowed
a reversal to the 50 gallon concentrator without a decrease in sludge con-
centration or reoccurrence of sludge carry over into the system effluent.
During solution to the septicity problem, the high fraction of dissolved BOD
in the influent was identified. This resulted in higher than desired BOD in the
effluent. Several candidate methods for oxidation and adsorption of BOD were
evaluated in a shore based laboratory utilizing actual ships wastes during the
period April through August 1971. Of the methods evaluated, only granular
activated carbon had any appreciable effect in reducing the Gerig's soluble
BOD. Based on the laboratory results, full scale carbon absorption equipment
was installed aboard the Gerig in July 1971 to demonstrate and evaluate the
effectiveness of granular activated carbon for BOD reduction.
Four carbon columns were installed on the Gerig downstream of the solids
separator. Each was 12 inches in diameter by 60 inches high and filled a
3-1/2 foot column (70 pounds) of granular activated carbon (DARCoQP 8 x 35
mesh, Atlas Chemical Co.). These columns were operated in series and the
flow was maintained at 4. 6 gpm. Flow was in an upward direction in each
column. Downstream of the carbon columns was an aeration tank followed by
effluent chlorination. The effluent from the aeration tank was automatically
diverted either to the chlorinator or recycled back to the first carbon column.
The prototype carbon absorption system selected for installation on the Gerig
was designed to meet the particular requirements imposed by shipboard use.
The upflow mode of operation offers an advantage over typical land based
packed-bed columns in that up-flow operation eliminates the fouling and solids
build-up associated with packed-bed operation. This precludes the necessity
for frequent back flushing of the bed to remove the particulate build-up.
Secondly, literature references indicate that essentially the same treatment
is obtained for either mode of operation.
The size of the carbon columns and grade of carbon was selected to obtain a
minimum two month carbon life while treating the entire Gerig effluent.
DARCOvS/ 8 x 35 mesh carbon is a waste water carbon. The fine mesh size
gives the benefit of a greater capacity and a higher rate of absorption of
organics from the waste water than a carbon composed entirely of coarse mesh
particles.
Testing was terminated in Moorehead City, N. C. in August 1971. At the time
of test completion, the life of the carbon columns was far from expended, as
evidenced by the fact that BOD reduction was occurring exclusively in the first
two columns of the four column series. The first two columns were not ex-
pended and the remaining two were essentially unused.
37
-------
The carbon column configuration, which occupies very little floor space, lends
itself to replenishment by removal of one column at a time. By suitable PVC
hand valves, the sequence of the columns can be easily changed and replacement
of a column can be accomplished while the waste treatment system is operating.
38
-------
SECTION V
RESULTS AND ANALYSIS
A. Summary-Biochemical Performance
During the course of the study the treatment system was required to treat waste
in a wide variety of background waters. Initial shipboard testing in October
1970 was performed with fresh water as the ships supply. The ship then op-
erated along the Gulf coast, around the Florida coast and northward to North
Carolina. During the sea trials, sea water was used as the flushing water in
heads. When the ship was dredging and dumping, the water supply to the sani-
tary system often contained large amounts of grit, sand or mud.
System operating temperatures were largely determined by the ambient water
and air temperatures of the ships location. Process temperatures varied from
75ฐF (Brunswick, Ga.) to 100ฐF (Boca Grande, Fla.)0
The influent flow rates to the systems varied widely during the study; from an
estimated 5900 gpd at the beginning of the study to 1500 gpd at the end. At one
point the flow was as low as 700 gpd. Typical system duty cycles are shown in
Figure 17.
Inspection of the analytical data summary, Table 7, shows that the BOD and
suspended solids content of the influent increased significantly during the course
of the study. This is thought to be due to more and more rigid enforcement of
overboard dumping regulations. The captain and officers of the Gerig strictly
enforced these regulations.
Sea trials started in December, 1969. Process performance of the systems was
monitored by on-board instrumentation per Table 8. Shore based laboratory
analysis of BOD, Coliform, and suspended solids began after adjustment of floe
aid and chlorine addition rates. Daily averages of biochemical performance,
during sea trials, are shown in Table 7ซ A complete compilation of the water
analysis data is contained in Appendix B.
A biochemical evaluation of the system was conducted prior to leaving the ship-
yard in October. During this period the sanitary water used by the ship was
Tampa City water. Laboratory analysis indicated that the system was capable
of treating the Gerig's waste to the approximate target levels of 50 ppm BOD and
39
-------
4.0
>
<
3.0
O_
ID
9 Z.O
1.0
APRIL 16, 1971 (FRI)
HALF CREW, ALL WASTES
BOCA GRANDE, FLA.
TOTAL FLOW 1024 GAL
4.0
Q. 3.0
LJ
1
LL)
CO
2.0
1.0
APRIL 15, 1971 (THURS)
AFT SEWAGE LOAD
USACE GERIG
FULL CREW
GALLEY, SHOWER, LAUNDRY
SANITARY WASTES
TOTAL FLOW 1541.7 GAL
BOCA GRANDE, FLA.
CREW
SHORE
LEAVE
0000 0200 0400 0600 0800 1000 1200 1400
LOCAL TIME
1600
1800
2000
2200
2400
Figure 17. Typical Gerig Hydrograph During Sea Trials
-------
TABLE 7. DAILY SHIPBOARD WASTE TREATMENT SYSTEM WATER ANALYSIS AVERAGES
Location/Dates
Tampa Shipyard
10-27-70
10-28-70
10-29-70
Averages
Pascagoula, Miss.
1-8-71
1-9-71
1-10-71
1-11-71
1-12-71
1-13-71
Averages
Brunswick, Ga.
3-11-71
3-13-71
3-14-71
3-15-71
3-16-71
3-17-71
3-19-71
BOD5*
Inf. Eff.
78
270 79
170 65
220 74
140 15
190 20
270 75
150 40
200 15
45 40
166 33
575 220
1000 315
375 183
1070 216
630 -
320 219
430 393
S.S. ppm
Inf. Eff.
45
488 25
566 57
527 42
420 20
150 20
430 5
1340 10
- 10
65 15
481 13
692 54
907 47
497 70
617 19
688 58
390 83
360 66
PH
Inf. Eff.
8.4 9.6
8.2 9.1
_
_ _
__
7.0 8.4
7.4 8.6
7.0 -
7.5 7.5
7.1 7.9
Res.
ci2
ppm
_
1
22
29
Colif.
Col. /100ml
>1 x 103
>1 x 103
>1 x 103
Comments
Operating on Tampa City Water
at Shipyard
Excessive water flow due to high
flushometer settings
No ship power - system septic as
evidenced by effluent odor, color,
positive ORP and low DO.
Low flow - system septic
System septic
*Represents an average of 4 influent and 4 effluent samples.
-------
TABLE 7. DAILY SHIPBOARD WASTE TREATMENT SYSTEM WATER ANALYSIS AVERAGES (Continued)
L o c ati on/Dat e s
3-20-71
3-21-71
3-22-71
3-23-71
3-24-71
3-25-71
3-26-71
3-27-71
3-28-71
3-29-71
3-30-71
3-31-71
4-1-71
4-2-71
4-3-71
4-4-71
4-5-71
4-6-71
4-7-71
4-8-71
4-9-71
Averages
BOD5
Inf. Eff.
805 272
730 172
700 282
667 241
645 202
272 202
498 206
506 306
607 224
385 175
1120 87
320 155
915 330
1000 164
585 261
547 250
715 219
502 246
657 213
510 191
390 183
625 218
S. S. ppm
Inf. Eff.
550 60
590 47
570 48
490 87
710 108
320 78
560 60
460 48
415 107
150 18
630 18
290 43
600 46
860 25
390 36
310 77
520 69
430 71
560 60
525 56
pH
Inf. Eff.
7.4 8.1
7.5 8.8
8.2 8.8
7.8 8.1
6.9 8.7
7.4 8.7
7.5 8.6
7.2 8.4
7.3 8.6
7.6 8.9
7.3 8.5
8.0 8.6
7.7 8.0
7.6 8.6
7.6 8.7
7.2 7.6
7.0 7.6
6.4 8.1
7.6 8.1
7.5 8.8
7.6 8.5
Res.
ci2
ppm
62
17
23
97
68
34
47
20
39
80
118
27
22
17
57
23
35
88
44
27
82
Colif . .
Col. /100ml
>1 x 103
<1.0
<1.0
<1.0
<1.0
2 x 103
<1.0
>1 x 103
<1.0
<1.0
<1.0
9
<1.0
<1.0
<1.0
<1.0
<1.0
3
235
Comments
Air bubbler added.to effluent
chlorination tank
to
-------
TABLE 7. DAILY SHIPBOARD WASTE TREATMENT SYSTEM WATER ANALYSIS AVERAGES (Continued)
Location/Dates
Boca Grande, Fla.
4-16-71
4-17-71
4-19-71
4-20-71
4-21-71
4-22-71
Averages
Southport, N.C.
4-29-71
4-30-71
5-1-71
5-6-71
5-10-71
5-11-71
5-12-71
5-16-71
5-17-71
5-18-71
BOD5
Tot. Sol.
Inf. Inf. Eff.
975 60 61
500 135 225
690 345 42
305 130 68
440 100 42
830 480 32
534 178 78
772 225 128
590 236 210
450 220 215
780 250 320
740 380 240
370 - 450
1100 590 292
445 _ 166
746 415 267
480 195
S.S. ppm
Inf. Eff.
1880 550
2060 500
1110 115
920 70
540 140
2420 180
1490 257
715 55
320 33
250 150
- 85
650 60
810 75
750 79
360 47
390 59
380 35
PH
Inf. Eff.
8.7 9.0
7.5 8.9
7.8 9.0
8.0 8.0
7.3 8.9
6.9 9.2
7.4 9.1
7.9 8.8
6.9 9.3
8.2 9.5
Res.
ci2
ppm
26
13
47
17
8
18
16
24
19
18
Colif.
Col./lOOml
<1.0
<1.0
Comments
High effluent solids due to blan-
ket carry-over -at initiation of
recycle
EC cell power supply failure
Intermittent EC cell operation;
power supply troubleshooting
CO
-------
TABLE 7. DAILY SHIPBOARD WASTE TREATMENT SYSTEM WATER ANALYSIS AVERAGES (Continued)
Location/Dates
5-24-71
5-25-71
5-26-71
6-20-71
6-21-71
6-22-71
6-23-71
6-24-71
6-25-71
6-26-71
7-7-71
7-8-71
7-9-71
7-10-71
Averages
7-14-71
7-15-71
BOD5
Tot. Sol.
Inf. Inf. Eff.
330 140 207
787 367
730 - 340
300 - 147
200 575
290 - 180
880 170
180 - 170
400 155
590 205
390 170
731 440 234
430 340 293
533 316 248
440 47
600 61
S. Sซ ppm
Inf. Eff.
520 90
670 27
780 39
550 64
1510 20
1570 11
pH
Inf. Eff.
8.7 9.1
8.3 9.2
7.8 9.1
7.4 9.0
6.7 8.9
9.2 8.9
8.6 9.5
6.1 8.8
7.1 8.9
7.2 7.2
8.7 9.2
8.6 7.6
7.9 8.0
Res,
C12
ppm
40
25
55
_*
_*
_*
33
11
17
69
45
5
0
Colif.
Col. /100ml
Comments
KMnC) added to clarifier
4
Discontinued use of KMnO
4
Carbon column in operation
*KMnO used in conjunction with chlorine.
-------
TABLE 7. DAILY SHIPBOARD WASTE TREATMENT SYSTEM WATER ANALYSIS AVERAGES (Continued)
Location/Dates
7-16-71
7-17-71
7-19-71
7-20-71
7-21-71
7-23-71
7-26-71
7-27-71
7-29-71
7-30-71
8-1-71
8-2-71
8-5-71
8-7-71
8-8-71
8-9-71
Averages
BOD5
Tot. Sol.
Inf. Inf. Eff.
380 125
220 - 90
400 120 50
600 160 69
240 140 60
580 330 109
340 170 60
720 440 44
340 115 66
330 80 108
- 132
840 280 150
1200 540 200
1200 510 198
360 160 60
990 430 64
575 267 94
S.S. ppm
Inf. Eff.
1180 14
500 5
580 22
1770 38
420 30
580 101
460 65
640 36
390 75
230 53
290 55
460 155
756 49
pH
Inf. Eff.
7.8 7.8
8.2 7.5
8.7 7.7
8.8 8.1
8.5 7.7
7.9 8.0
4.4 7.4
8.8 7.4
7.8 9.0
7.9 8.7
9.0 8.6
7.7 8.6
8.2 8.8
7.8 8.5
8.6 8.7
8.0 8.7
-
Re a.
C12
ppm
0
0
0
0
0
0
0
0
75
29
26
12
9.0
Colif.
Col. /100ml
Comments
160 gal. Concentrator Removed
50 gal. Concentrator Installed
Columns septic as evidenced by
odor, color, positive ORP and
low DO
Aeration Added
en
-------
TABLE 8. ON-BOARD INSTRUMENTATION
Analytical Instrumentation For On-Board Monitoring Of System Performance
Performance
Instrument/Method
1, Residual Chlorine
2. Iron
3. Dissolved Oxygen
4. Conductivity
5. pH
6. Oxidation-Reduction Potential
70 Turbidity
8. Turbidity
9. Sludge Settle ability
Automatic Titrator
Phenylarsene Oxide
Hach Field Test Kit
Beckman Probe
Honeywell Probe
Beckman pH Probe
Beckman Probe
Hach-Falling Stream
Hach-Back Scatter
Bird - Gang Stirrer
Note: Items 3 through 7 were incorporated into an automated water
quality monitor.
100 ppm suspended solids. BOD and suspended solids reductions of 66 and 92
percent respectively were obtained,, Average values for this period were:
Influent
Effluent
220 ppm
74 ppm
S.S.
527 ppm
42 ppm
Influent resembled standard municipal waste chemically and physically.
At Pascagoula/Gulfport in January 1971 the Gerig was dredging approximately
10 miles offshore in sea water. The conductivity of the influent to the waste
treatment system varied from 30, 000 to 50, OOOju mhos/cm,, Reduction of 80
percent in BOD and 97 percent in suspended solids was achieved. Average
values for this period were:
Influent
Effluent
166 ppm
33 ppm
S.S.
481 ppm
13 ppm
46
-------
The influent again had the general appearance (chemical and physical) of domes-
tic waste. It was noted however, that due to the excessive flows, which were up
to 200 percent of the design flow rate, the solids blanket would periodically
carry over the clarifier weir. The actions taken to correct this were to recali-
brate the toilet flushometers to their specified operating range and installation
of a larger solids concentrator in order to give more capacity for the retention
of separated solids.
As a result of satisfactory biochemical performance, an intensive 30-day sys-
tem performance evaluation at the next dredging area, Brunswick/Savannah,
Ga., was begun. Here the Gerig worked in sea and estuarine water. During
March and April, 1971, laboratory analyses were performed by personnel from
the General Electric Environmental Sciences Laboratory and the Cincinnati
Water Quality Office of the Environmental Protection Agency. The work was
performed in a mobile laboratory facility supplied by Environmental Protection
Agency, Cincinnati.
A significant increase in both influent and effluent BOD was observed. Also it
was found that the low duty cycle of the system, at the adjusted influent flow,
caused the development of anaerobiosis in the system. Corrective measures
were incorporated into the system operations in order to reverse the anaerobic
tendency. This involved the introduction of chlorine into the clarifier and sludge
concentrator during the daily 14 hour low flow periods. In addition the chlorine
feed to the effluent was adjusted to give a minimum residual of 20 ppm. During
this test period average values were:
BOD5 S.S.
Influent 625 ppm 525 ppm
Effluent 218 ppm 56 ppm
Reductions of 64 and 89 percent were achieved for BODg and suspended solids
respectively. The data showed extreme variability, influent BOD's ranged
from a low of 100 ppm to a high of 1980 ppm. Influent suspended solids loadings
were also quite variable, daily averages ranging from 300 to 1000 ppm, with
individual values as low as 40 and as high as 1600 ppm.
The Gerig proceeded to Boca Grande, Florida in mid April 1971 where steps
were taken to prevent the development of septicity which was thought to be a
contributing factor to the high effluent BOD. A continuous, clarifier to sludge
concentrator, chlorinated recycle system was installed. This maintained an
oxidizing environment in the system which prevented the establishment of con-
ditions for anaerobic growth. After it was established that no anaerobic growth
47
-------
was occurring by intensive measurement of parameters such as ORP, DO levels,
chlorine demand, pH and odor, BOD testing was resumed.
Analysis at an independent laboratory gave the following results after six days
of testing:
Total Soluble Total
BOD5 BOD5 Suspo Sol.
Influent 534 178 1490
Effluent 78 - *257
*Due to solids carry-over during system adjustment.
Percent reduction was 85 and 83 for BOD5 and suspended solids respectively.
The data also indicates that the soluble fraction of the BOD was approximately
30 percent of the total.
In light of these results it was decided to resume demonstration testing in the
area of Southport/Wilmington, North Carolina. The Environmental Protection
Agency mobile laboratory facility was again employed, manned by General
Electric personnel who had been trained previously in the EPA analytical
methods. High effluent BOD's were again obtained.
Average values were:
BOD5 TSS
Influent 553 550
Effluent 248 64
Regular determinations of the soluble fraction of the influent BOD were in-
corporated into the test program,, The soluble portion averaged approximately
60 percent of the total. An intensive laboratory test program was initiated in
order to determine the source of the soluble material. A survey of the ship
identified several sources of soluble BOD0 An investigation to determine a
means of chemically oxidizing this material within the existing system config-
uration was unsuccessful. Carbon adsorption was added to the system in July
1971. The carbon columns were installed to accept the system effluent; initial
performance was excellent. A tendency toward septicity was found after several
days of operation. This was due to inadequate aeration of the columns, again, a
strong function of low system duty cycle (3-4 hours out of 24). A continuously
aerated recycle loop was installed for periods when the system was inoperative.
This was able to keep the columns aerobic and they recovered their activity.
48
-------
Averages for this period were:
BOD5 S,So
Influent 575 756
* Effluent 94 (78) 49
*If values where the columns were septic are neglected, the mean effluent
BOD5 was 78 ppm
While the carbon columns were installed, the percent reduction for BOD and
So So were 84 and 93 respectivelyo
The carbon columns performed quite well with the exception of the development
of septicity due to inadequate aeration (see Table 7, 7/14/71 to 8/9/71). At the
time of installation the system influent flows were on the order of 900-1600
gpd, resulting in 3 to 5 hours of operating time per day. No air was admitted
during the non-operating time and additional column compaction occurred. To
provide a constant air supply and prevent increases in packing density, a re-
cycle loop was installed (see Figure !) In this mode of operation a constant
supply of air saturated water was presented to the column when the treatment
system was not processing,, This kept the columns aerobic and also helped to
maintain uniform packing density to prevent channeling.
The columns were not installed for a long enough period to determine their total
capacity for the dissolved BOD material The efficiency of the columns de-
creased when there was septicity, however, this was reversed when the columns
were made aerobic
Coliform determinations were routinely performed at Tampa, Flaป and Bruns-
wick, Ga. (Table 7)o Spot checks were also made at Southport, N.C. Coliform
bacteria levels were easily controlled in the effluent throughout the test to less
than the target value of 240 MPN col/100 ml. It was also found that sudden or
persistent rises in effluent coliform count could be used as an indicator for
problems elsewhere in the system such as septicity or solids carryover. The
chlorinated recycle mode of operation maintained a sufficient level of chlorine
throughout the system to prevent the growth of coliform organisms.
Conclusions
The ship's combined influent waste showed extreme variability over very short
operating cycles. Variation occurred in almost every parameter measured.
The most striking however, were the range of suspended solids and BOD con-
centrations o
49
-------
The persistent presence of such a large soluble and refractive BOD fraction
puts the Gerig influent into the industrial rather than domestic, waste category.
The data imply that the large soluble fraction was contributed by common
ship's cleaning chemicals that are used for routine maintenance and can be ex-
pected to be constantly found in the influent.
The growing enforcement of overboard dumping restrictions will serve to in-
crease the strength of waste to be treated,, This will be true for "sanitary
only" situations as well as for treatment of total waste since much of the sol-
uble BOD causing material can be easily disposed of into urinals, toilets and
head drains
Chemical results from independent laboratories were often found to be erratic
and sometimes varied widely between different labsป This was judged to be
due to their lack of experience in measuring high strength waste and consequent
lack of adjustment for increased waste concentrations. It is our conclusion that
the analysis should be performed by a laboratory that has some experience with
water type to be analyzed. Critical information that is required by the analyst
and must be adjusted for in the test procedure is:
1. Extreme range in sample strength (factor of 20 possible).
2. High immediate oxygen demand (IOD),,
3o Very high chemical oxygen demand (COD),,
4. Presence of toxic chemicals.
5. Higher than normal chlorine content.
60 Interference of waste chemicals with test reagents.
B. Discussion - Biochemical Performance
The results of an earlier intensive, in-house test program (See Appendix A)
indicated that the General Electric system would be able to treat shipboard
waste to the desired target levels. This implied BOD loadings on the order
of 400-500 ppm with approximately 75 percent of the BOD constituents being
suspended material. It was anticipated that excesses in soluble BOD could be
reduced by oxidation with chlorine. Suspended solids and coliform removal
had been demonstrated to be excellent under all operating conditions. The
actual wastes from the Gerig, however, proved to be quite different from those
encountered using sanitary office building waste and simulations of shipboard
waste. The average soluble portion of the BOD aboard the ship was on the
50
-------
order of 50 percent. When the influent total BOD was highest (1000 to 2000 ppm)
its major component was soluble (60 to 80 percent). The result of this high solu-
ble BOD fraction prevented meeting the target levels with the system as origi-
nally configured.
As a result of the BOD problem, a field laboratory analysis program was initiated.
Its objectives were to attempt to identify the causative factor for the high soluble
BOD loadings and to develop an environmentally compatible chemical treatment
process for oxidation of this material.
As the first step in the investigation, a comparison was made of analytical tech-
niques between the Standard Environmental Protection Agency method (references
5 & 6) and those used by two independent testing laboratories. Wide variation in
results between the three laboratories was found in the analysis of simultaneously
analyzed samples of system influent and effluent. Further investigation indicated
that the independent laboratories varied from the Standard Method (reference 5)
in ways that could lead to obtaining low results. On the basis of these results,
it was decided that all systems performance evaluation would be conducted by
EPA trained GE personnel using the EPA modification of the standard method.
A further modification was made when further study showed that the Winkler
titration agreed with the results obtained using a Weston and Stack dissolved
oxygen meter. This modification allowed a significant increase in the number
of samples that could be processed.
As the second step in the program, a survey of the Gerig was made to determine
what soluble materials were used during routine ships operation that could find
their way to the waste treatment system. Nine cleaning compounds were identi-
fied. 100 ppm concentrations of these components were tested for BOD activity.
A standard solution of glucose/glutamic acid was made up as a BOD test check.
This mixture had a 5-day BOD of 220-240 ppm. Constant volumes of the stan-
dard mixture were made at concentrations of 100 ppm for each of the ship's
chemicals. In addition, the ability to oxidize these materials with chlorine was
determined. Simultaneous samples were set up of each compound. A control
sample and one which had a concentration of 35 ppm chlorine were tested. The
results are shown in Table 9. Five of the compounds showed high levels of
BOD5 activity in concentrations of 100 ppm and none were oxidized by chlorine
at levels of 35 ppm. It can be assumed that any one or all of these compounds
were present in the waste system influent at any time during the day due to the
around the clock operation of the ship.
A laboratory program was then initiated in order to determine a method for oxi-
dation of the soluble BOD portion in the system effluent. In the interests of
51
-------
TABLE 9. EFFECT OF CHEMICALS IN GERIG INVENTORY ON
GLUCOSE/GLUTAMIC ACID BOD
No,
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Chemical
Laundry Detergent A
Pine Oil A
Solvent Degreaser
(Chlorinated Hydro-
carbon)
Descaler
Sol vent /Deter gent
Paint Brush Cleaner
Pine Oil B
Laundry Detergent B
Toilet Cleaner
Combination 1-9
Glutamic Acid/
Glucose**
ppm
100
100
100
100
100
100
100
100
100
100
No C12
BOD2 BOD5
147 150
197 DepL*
376 Depl. *
40 110
Depl.* DepL*
140 200
Depl,,* DepL*
DepL* DepL*
85 150
Depl.* DepL*
140 210
35 ppm C\2
BOD2 BOD5
138
220 DepL*
210 DepL *
6 150
DepL* DepL*
180 -
DepL* DepL*
DepL* DepL*
150
DepL* DepL*
~~ ~~
*Depl. (Depletion) samples = BOD > 500 ppm
**A glutamic acid/glucose mixture was used as a check on the BOD procedure.
BOD5 of this solution should be 220-240.
economic and operation practicality, the following factors were considered to
be of prime importance in the selection of soluble BOD reduction methods:
1. Environmental acceptability.
2. Safe for shipboard storage and handling.
3. Economic feasibility.
4. Require minimal system modification.
52
-------
The following physical and chemical methods were tried in the laboratory or in
the system with negative or insignificant results:
% Reduction - Sol. BOD
Chlorine (up to 100 ppm) 0
Chlorine and elevated temp. (140ฐF) 0
Increased aeration efficiency (air or 0
oxygen) (Table 10)
Potassium permanganate (Table 11) 0
Ozone (Table 13) 50
(2)
Hydrogen peroxide (Table 14) 0
(3)
(1) Apparent successful reducation was shown to be due to toxicity to
BOD seed organisms. When KMnO^ was completely neutralized
before setting up the BOD, it was found to have no effect under
the conditions tested (Table 12 and Figure 18).
(2) Ozone was ruled out for reasons of possible toxicity problems in
the close quarters of the hold, length of required holding time,
and expense of equipment.
(3) Hydrogen peroxide was not completely ruled out. Negative results
were due to seed inhibition but there was no opportunity to neu-
tralize the residual H2O2 and retest. Stable, high concentration
mixtures are available.
On the basis of this lab program, it was determined that the soluble fraction of
Gerig influent could not be oxidized within the limits of the above ground rules
by any conventional chemical treatment known to investigators.
It was then decided to look at the feasibility of BOD reduction with activated car-
bon. A bench test was performed in which 1000 ppm of powdered activated car-
bon (DARCO S-51) was added to the coagulated influent (EC cell effluent) and
allowed to precipitate. The BOD of the filtrate was measured before and after
contact and showed no reduction due to carbon contact under these conditions.
A laboratory column was then set up using 8 x 20 mesh granular activated char-
coal (DARCO). Preliminary results are shown in Table 15. On the basis of
previous information from the literature and the preliminary laboratory data, a
53
-------
TABLE 10. EFFECT OF AERATION ON BOD5 REDUCTION
IN GERIG EFFLUENT
Effluent
Sample Number
1
1
1
2
2
2
Aeration Time
0
30 min
60 min
0
30 min
60 min
Res. Chlorine
(ppm)
68 ppm
68
68
42
42
42
BOD5
(ppm)
340
220
300
340
340
340
EFFECT OF OXYGENATION ON BOD5 REDUCTION
IN GERIG EFFLUENT
Effluent
Sample Number
1
1
2
2
Oxygenation Time
0
30 min
0
30 min
Res. Chlorine
(ppm)
48
42
28
26
BOD5
(ppm)
145
160
245
245
54
-------
TABLE 11. EFFECTS OF POTASSIUM PERMANGANATE ON SYSTEM EFFLUENT BOD5
Ul
Ul
Date
5-29-71
5-29-71
5-29-71
5-29-71
5-29-71
5-29-71
5-29-71
5-29-71
5-29-71
5-29-71
5-29-71
5-29-71
5-29-71
6-7-71
6-7-71
6-7-71
6-7-71
6-7-71
6-7-71
6-7-71
6-7-71
6-7-71
6-8-71
6-8-71
6-8-71
6-8-71
Sample Designation
Effluent "C"- 1
Effluent "C" +25 ppm KMnO4
Effluent "C" +50 ppm KMnO4
Effluent "C" 100 ppm KMnO4
Effluent "C" 250 ppm KMnO4
Effluent "C" 500 ppm KMnO4
Effluent "C" -2
Effluent "C" +25 ppm KMnO4
Effluent "C" 50 ppm KMnO4
Effluent "C" 100 ppm KMnO4
Effluent "C" 250 ppm KMnO4
Effluent "C" 500 ppm KMnO4
Effluent "C"
System Effluent +50 ppm KMnO4
System Effluent 100 ppm KMnO4
System Effluent 250 ppm KMnO4
Std. Glucose/Glutamic Acid
Std. Glucose/Glutamic +25 ppm KMnO4
Std. Glucose/Glutamic +50 ppm KMnO4
Std. Glucose/Glutamic +100 ppm KMnO4
Std. Glucose/Glutamic 250 ppm KMnO4
Std. Glucose/Glutamic 500 ppm KMnO4
System Effluent 0930
System +50 ppm KMnO4
System 100 ppm KMnO4
System 250 ppm KMnO4
pH
-
-
-
-
-
-
-
-
-
-
-
9.2
-
-
-
-
-
-
-
-
-
9.3
-
-
-
Residual
Chlorine
ppm
-
-
-
-
-
-
-
-
-
-
-
26
-
-
-
-
-
-
-
-
-
34
-
-
-
BOD2
ppm
_
-
-
-
-
-
-
-
-
-
-
-
135
140
48
0
150
0
0
0
0
0
115
105
10
3
BODs
ppm
140
160
140
115
70
33
190
200
190
195
140
13
210
220
150
0
190
0
0
0
0
0
285
260
3
0
-------
TABLE 12. SYSTEM EFFLUENT TREATED WITH KMnC>4 AT
37ฐC FOR 60 MIN. THEN NEUTRALIZED WITH
SODIUM THIOSULFATE
Effluent Sample
Number
1
1
1
2
2
2
3
3
3
4
4
4
KMnO4
(ppm)
0
100
150
0
100
150
0
100
150
0
100
150
BOD5
(ppm)
220
240
245
230
240
280
300
260
300
300
290
320
TABLE 13. EFFECT OF OZONE ON BOD&
REDUCTION IN GERIG EFFLUENT
Effluent
Sample
Number
1
1
1
2
2
2
Ozone Exposure
0 min (0 ppm)
10 min (73 ppm)
60 min (450 ppm)
0 min (0 ppm)
10 min (73 ppm)
60 min (450 ppm)
Res. C12
(ppm)
45
45
45
1
1
1
BOD5
(ppm)
300
250
160
160
110
85
56
-------
TABLE 14. EFFECT OF HYDROGEN PEROXIDE ON BOD5
REDUCTION IN GERIG EFFLUENT*
Effluent Sample
Number
1
1
1
1
2
2
2
2
3
3
3
3
H202
(ppm)
0
300
400
500
0
300
400
500
0
300
400
500
BOD5
(ppm)
165
-
140
180
165
80
215
140
190
235
360
Depleted
*Dissolved Gฃ for the seed conrols were higher at the end of the
5 day period than at the beginning. Un-neutralized H2ฎ2
interfered with seed and reagents.
carbon column subsystem was developed for use aboard the Gerig. The column
was installed to accept the clarified system effluent. Average suspended solids
and BOD5 values for this period are:
BOD5 Suspended
System Influent
Influent to Carbon Columns
System Effluent
*Several high values were obtained during system malfunctions
(anerobiosis, carbon carryover). When these values are removed,
the corrected average is 38 ppm.
Detailed data is shown in Table 16.
ppm) (ppm)
570
158
94
750
47
*53
(38)
57
-------
160
140
120
100
80
Q.
Q.
I
40
Q
O
CD
60
40
20
100
200 300 400
PERMANGANATE-ppm
500
Figure 18. Effects of KMnO4 on BOD5 Due to Seed Poisoning
58
-------
TABLE 15. RESULTS OF GRANULAR CARBON COLUMN TEST
Sample Designation
System Effluent of 6-26-71
Column Effluent - 1 hour
Column Effluent - 1-1/2 br
Column Effluent - 2 hours
pH
8.6
9.2
9.3
9.3
Residual
Chlorine
(ppm)
8.6
0
0
0
BOD2
(ppm)
100
32
30
30
BOD5
(ppm)
170
46
48
42
Column Dimensions = 1" Diam x 6' Height
Flow Rate = 60 ml/minute
Analytical Notes
Residual Chlorine:
The HACH ortho-tolidine method was found to give low results when the strength
of the waste was high. The phenylarsene oxide reduction technique gave reliable
results over a wider range of waste strengths.
Suspended Solids/Turbidity:
Turbidity changes as a function of particulare characteristics as well as particle
concentration, both of which vary widely in the influent and effluent. No consis-
tent correlation was established between turbidity and suspended solids
concentration.
Automated Analysis:
The chlorinated system effluent was routed through an automatic recording ana-
lyzer. Simultaneous readouts could be obtained for: residual chlorine, oxidation-
reduction potential, pH, dissolved oxygen and turbidity. This proved to be an
invaluable diagnostic tool for the monitoring of system performance. It is recom-
mended that this type of monitoring be used routinely in system performance
evaluation.
Data Interpretation:
In our studies it was found that the two-day BOD was reliable 60 percent of the
five-day BOD. By use of the dissolved oxygen probe, it was possible to
59
-------
TABLE 16. RESULTS OF FULL SCALE CARBON COLUMN OPERATION
Date
7/14
7/15
7/16
7/17
7/18
7/19
7/20
Sample
Time
1100
1310
1415
0830
0900
0810
0830
0810
1330
0900
1100
1300
1400
0800
0915
1015
1400
Influent
BOD5 S.S.
(ppm) (ppm)
440 1512
520 1570
280 1175
220 500
360 1020
400 580
600 1770
Influent to
Column
BOD5 S.S.
(ppm) (ppm)
230 34
160 27
280 43
150 41
150 26
120 26
130 20
120 38
205 54
80 50
170 66
130 45
210 45
Effluent from
Column
BOD5 S.S.
(ppm) (ppm)
50 20
60 2
60 20
160 12
100 16
90 55
80 6
70 17
70 24
60 15
50 28
60 25
70 30
80 60
Remarks
Coliform in effluent "too numerous
to count"
-------
TABLE 16. RESULTS OF FULL SCALE CARBON COLUMN OPERATION (Continued)
Date
7/21
7/22
7/23
7/24
7/25
7/26
Sample
Time
0800
0800
0840
0810
1200
1330
1430
9815
0820
1300
1500
Influent
BOD S. S.
(ppm) (ppm)
120 420
500 580
340 460
Influent to
Column
BOD S. S.
(ppm) (ppm)
65 24
130 51
120 14
120 40
140 20
Effluent from
Column
BOD S. S.
(ppm) (ppm)
30 30
70 50
90 144
40 40
50 95
90 60
Remarks
Column fluidized at high flow rate
to correct channeling. Done on
basis of 7/16-17 BOD5 which
indicated performance degradation
which in fact did not occur.
High solids are carbon. Evidently,
a result of previous days flushings.
Sludge recycle pump failed (approx.
3000 hrs.) resulting in septicity.
Configuration change to add chlor-
ination downstream of carbon column
and provide aerated water to column.
-------
TABLE 16. RESULTS OF FULL SCALE CARBON COLUMN OPERATION (Continued)
Date
7/27
7/28
7/29
7/30
8/1
8/2
Sample
Time
0830
1100
1230
1445
0830
1430
0830
1345
0845
1240
1400
0825
0845
1245
1400
0940
1410
Influent
BOD S. S.
(ppm) (ppm)
720 640
490
340 390
330 230
250 287
840 456
Influent to
Column
BOD S. S.
(ppm) (ppm)
120 20
220 76
220 48
190 75
100 87
50 57
160 56
230 53
110 56
230 96
130 68
230 70
Effluent from
Column
BOD S. S.
(ppm) (ppm)
30 45
30 18
70 44
220 168
60 59
70 75
110 40
110 66
140 61
130 50
150 200
150 106
Remarks
Aeration of column broke down due
to failure of ship's air supply.
Column went septic. Was corrected.
Effluent odoriferous. Suspect either
aeration of chlorine feed malfunction.
Effluent odoriferous. Effluent
chlorine pump malfunction. Corrected
Effluent septic due to chlorine pump
and PSG failure.
to
-------
TABLE 16. RESULTS OF FULL SCALE CARBON COLUMN OPERATION (Continued)
Date
8/5
8/7
8/8
8/9
Sample
Time
1300
1400
1130
1215
1420
0820
1210
1410
0835
1225
1410
Influent
BOD5 S. S
(ppm) (ppm)
1200
1200
360
990
Influent to
Column
BODg S. S.
(ppm) (ppm)
200
190
190
130
220
115
80
Effluent from
Column
BOD S. S.,
(ppm) (ppm)
200
200
200
50
70
60
70
Remarks
Effluent septic due to chlorine
pump and PSG failure.
Effluent odoriferous. Everything
working.
*
CO
-------
significantly decrease laboratory time by reading two-day BOD's without having
to increase the number of samples set up. (Table 17).
TABLE 17. COMPARISON OF TWO-DAY AND FIVE DAY BOD DATA
Sample Designation
System Influent
System Influent
System Influent
System Influent
System Influent
System Influent
System Influent
System Influent
System Influent
System Influent
System Influent Average
BOD2
_ _ x 100 59%
BOD5
System Effluent
System Effluent
System Effluent
System Effluent
System Effluent
System Effluent
System Effluent
System Effluent
System Effluent
System Effluent
System Effluent Average
BOD2
BOD, X 10ฐ ~ 62%
o
BOD
2
ppm
160
430
310
160
200
540
135
460
130
280
281
77
150
90
180
170
170
140
60
110
70
122
BODn
2
ppm
260
620
450
500
260
1020
235
770
300
380
479
110
390
185
260
240
220
215
100
155
100
197
64
-------
Sample Preservation
Samples were collected in plastic containers and refrigerated immediately.
They were then transferred, in ice, from the ship to the laboratory. All sam-
ples were analyzed within 24 hours of collection.
C. Evaluation - Mechanical/Electrical Performance
Mechanical and electrical reliability are of more immediate importance to the
marine engineer and ship operator than effluent quality. The system developed
for this program is comprised of mechanical and electrical components of only
moderate complexity and are of the type easily maintained by a ship's engine
room crew at the apprentice level of skill with the aid of a simple manual.
The components selected for the system, as a whole, proved to be reliable for
the application; pumps, valves, motors, electrical devices, such as timers,
relays and switches, operated in the marine environment with no problems.
Certain selected devices did malfunction, resulting in selection of more reliable
components which were subsequently proven by many hours of operation; these
are described in more detail in the following.
Wear rates, particularly for pumps, were established and proved to be superior
to those component used in similar applications aboard the Gerig.
As part of the system evaluation, it became apparent that reduction of the num-
bers of parts could be achieved. These are included in the recommendations.
Electrocoagulation Cell
The electrocoagulation cell accumulated 750 hours of operation prior to need for
replacement of the steel plates. This is equivalent to the processing of 225, 000
gallons without replacement of coagulant. The need for replacement was deter-
mined when the iron output of the cell decreased below the objective of 70 mg/1.
Examination of the plates removed indicated that 210 of the initial 271 pounds
were consumed. The elapsed time between plate replacement can easily be in-
creased by thickening the plates. This has been proved to be true on subsequent
tests on other programs.
Operation of this cell with sanitary flushing waters ranging from fresh to sea-
water was accomplished with no difficulty in maintenance of the constant applied
current to the cell. Voltage required to maintain 100 amperes ranged from 3
to 10 volts.
65
-------
Teardown of the cell at plate replacement time revealed that deposited solids
remained in most of the horizontal flow passages such that flow passages had
become narrow channels.
Several conclusions may be drawn from the teardown. The simple horizontal
arrangement of consumable plates periodically exposed to low pressure air flush,
to dislodge any solids, did not perform the total clean out function; however,
without air flush, complete blockage would be incurred within a short period.
Further development of the electrocoagulation cell design requires a better mode
of solids removal possibly by reorientation of the plate assembly and more posi-
tive scrubbing. Periodic (once a week) clean out by an acid flush has proved to
be an effective clean-out technique on later designs.
Design of the sealed cell with provisions to safely conduct foam and hydrogen
gas from the operating compartment operated without incident.
Pump Grinder
The pump-grinder performed the primary function of comminution of solids and
flow delivery with no maintenance required until 1350 hours of operation. Com-
minution consistency in particle size was generally colloidal with nothing ex-
ceeding 0. 25 inch as determined in the total suspended solids measurements
made on the pump discharge effluent.
Replacement of the synthetic rubber stator of the Moyno ^-^ (Robbins and Meyers
Co. FS44) progressive-cavity pump was required at 1350 hours. Failure to de-
liver flow was observed and attributed to wear of the stator as accelerated by
the high sand content of the sanitary flush water. It was not necessary during
the sea trials to drain and clean out the base of this unit for removal of items
deli verately permitted to settle such as cutlery, bolts, and other inert obejects.
Upflow Clarifier/Concentrator
The upflow clarifier is the only component in this system whose primary function
would be affected by sea-state conditions. Maintenance of the sludge underflow
which depends upon gravity forces for solids settling was not adversely affected
by vessel motion at anytime in the test period. Supernatant total suspended solids
measurements were made on all samples obtained under the entire gamut of cli-
matic conditions.
At 340 hours of operation, it was necessary to replace the lower bushing of the
central downcomer stirrer due to binding. The lower bushing removed was a
Gutless ^ brass sleeve with neoprene molded insert, typical of units used on
66
-------
propeller shaft hull penetrations. In this application, sufficient sludge accumu-
lation impeded lubrication of the neoprene insert. A straight substitution of a
Teflon ^ bearing prevented any repetition of the problem during the subsequent
4000 hours of operation.
The hydrodynamic stability of the upflow clarifier proved to be troublesome dur-
ing early phases of the program. The balance of influent versus effluent and
sludge withdrawal rates is critical but can and was achieved. A reliable, main-
tenance free, sludge level detector would be extremely useful to insure preser-
vation of the hydraulic balance, and would increase the capacity of the waste
treatment plant by permitting higher flow rates. Earlier in the program, sensors
of the optical, sonic, and viscous type, were tried with little success.
Recent tests, not associated with this program, have established positively that
the concentrator may be eliminated from the system with no reduction in sludge
concentration. In fact, withdrawal of the sludge from the proper place in the
blanket results in an increase in concentration up to three percent with a propor-
tional reduction in incinerator load. Evaluation of a recently developed
Viscometer ^-' for sludge level detection also shows considerable promise for
control of sludge withdrawal.
Elimination of the sludge concentrator would remove one pump and associated
plumbing and electrical connections from the system as well as reducing system
weight and volume.
Carbon Columns
The activated carbon columns were implemented during the final month of test.
The columns were a direct scale-up from laboratory bench scale. Three hun-
UO.V.U. FUlUJ.v^ VL O.V.ULVCH,^ ^^^^i ^^o.^ 8 x 35 mesh, Atlas Chemical Co.)
were housed in four cylinders arranged such that flow was upward. It was found
necessary to maintain a continuous flow through the carbon beds to prevent
packing. By utilizing a recycle of aerated column effluent during slack periods,
septicity of the column was precluded. The fine mesh carbon yielded a higher
capacity and higher rate of absorption of organics than would a coarser mesh.
Operated at 4. 6 gallons per minute of upflow, the columns as sized should not
require replacement for a minimum of three months. Replacement would entail
removal of an individual column while operating with the remainder.
Power Supply
The power supply operated on 440 vac, 3-phase, and provided direct-current
voltage to the electrocoagulation cell plates at a constant current level. The
67
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unit consisted of a three-phase, motor-driven variac, three-phase transformer,
solid state rectification of each phase, and a solid state current control. Tran-
sitions in waste-water conductivity did not adversely affect the constant current
control.
The single failure of the power supply occurred when a silicon rectifier shorted
and caused overheating of the variac. Fuse protection was added to the variac
output and low voltage transformer output to the rectifier bank.
Sensors
Control sensors in an automated system assume greater importance when they
fail because of secondary system consequences. Since diverse sensor types
were used to control functions in this system, some observations may be drawn
concerning their reliability in this application:
1. Disphragm actuated switch: This type provided the most reliable level
sensing in sewage and sludge vessels by virtue of a large contact area
insensitive to build-up.
2. Conductivity probes: Sensors of this variety which seek to complete a
conductive path through the liquid medium were adversely affected by
spurious moisture paths on mounting plates in spite of protective
sleeving.
3. Bubbler sensor: The switch sensing pressure changes for flowing air
in response to level changes consistently clogged in the purging tube.
4. Sail switch: These sensors, sensing flow by exposing a paddle to the
fluid medium, failed because of fragile supporting linkages.
Materials of Construction
In keeping with the development intent of this program, it was decided that the
materials of construction for this system would depart from traditional marine
materials. All the key tanks in the system were constructed from 5052 aluminum
while the plumbing was rigid polyvinyl chloride (PVC).
Examination of the aluminum tanks, which were uncoated internally, revealed
absence of significant corrosion due to seawater. The solvent welded plastic
piping, which remained unpainted but otherwise received no special handling,
proved extremely reliable in the marine environment. A consideration not to be
lightly regarded is the relative freedom from solids accumulations observed
68
-------
when sludge pipes were disassembled. This has not been true with galvanized
steel threaded pipe used in similar applications.
Chemical Metering Pumps
The liquid chemical metering pumps utilized to supply the sodium aluminate
flocculant aid, and hypochlorite solution were single-acting adjustable disphragm
types. Priming of the suction and delivery flexible tubing was maintained with
ball check valves. A screen mesh filter was fitted on the suction tube. These
units did not perform reliably. Maintenance of these pumps was required at
frequent intervals. Loss of the initial calibration or prime was incurred due to
crystal buildup on the check valves. Since reliable operation of the metering
pumps is a must, alternate hardware or metering techniques are required.
A more reliable pump type, produced by Everchlor ^-^ , has subsequently been
evaluated and found to be reliable.
Sewage Pumps
The progressive-cavity pumps used to pass wastewater and sludge performed
reliably with minimum maintenance required. Of the system total of nine of
these pumps, only the unit in the pump-grinder required stator replacement
after 1350 hours of handling gritty influent. The single constraint on reliable
life of these pumps in sewage handling service would appear to be a precaution
against operating these pumps dry.
D. Analysis-Economic
Introduction
Although the shipboard waste treatment system installed on the Gerig was an
engineering prototype and not necessarily representative of a final commercial
design, the Gerig experience and later design activity by General Electric permit
a projection of the operating cost of the process to a typical ship owner.
Costs have been normalized to exclude items related solely to the testing program
while adding on costs related to normal long-term operation. The resulting cost
figures approximate the cost of operating a permanently installed, quantity pro-
duced system by 2500 GPD capacity.
Cost Assumptions
Several key assumptions had to be made in estimating the economics of the
treatment system since the nature and duration of the demonstration did not
69
-------
yield sufficient first hand experience. Estimates on equipment life expectancy
and overhaul requirements were based on conservative commercial practice in
lieu of long term operating experience. Although the prototype at times re-
quired manual control and monitoring of certain operations, the exclusion of
additional manpower cost for normal system operation was based on successful
experience with complete automatic control on other General Electric treatment
systems.
Since carbon adsorbtion was added late in the demonstration program, insuffi-
cient operating experience is available to accurately predict carbon bed replace-
ment frequency. However, on the basis of available operating experience and
prior research (reference 7), an efficiency of 0. 25 pound BOD per pound of car-
bon was assumed for this operating range with the carbon column aided by nor-
mal biological activity in the columns.
The actual cost of system installation onboard Gerig is not available. Sewage
collection lines were already present and hardware installation was performed
as part of a general ship overhaul.
Costing Method
All capital and replacement costs were reduced to an average annual cost over
a twenty year system life. A straight-line amorization of initial purchase price
was made. Since interest rate will vary with type of owner and time of purchase,
the cost of money was excluded. An estimate of annual overhaul expense is
shown, although actual overhaul may occur at a lesser frequency.
The system was assumed to be operated at full rated capacity, but the number
of days per year of operation was parameterized due to the large difference
among ships' operating time in coastal waters (see Figure 19).
Annual Cost
The complete system including incinerator and carbon adsorption columns
would have an initial purchase cost of $36, 900 if produced in quantity. Installa-
tion is estimated at $55,000 giving an initial total cost of $91, 900. This initial
cost and periodic overhauls would give a $5, 522 per year average fixed cost
over a twenty year life. To this fixed cost must be added a $11.45 per day
operating cost. Operating cost is comprised primarily of carbon replacement,
EC cell plate replacement, and incinerator fuel. Based on these costs, a sys-
tem operated for 200 days/year would have a total annual cost of $7, 812 (see
Tables 18 and 19). Without carbon adsorption, this cost would be reduced 12
percent to $6867.
70
-------
2-
10-
CO
O
o
6-
4-
2-
(6,667)
(8,957)
(7,812)
FIXED COST (5,522)
100 200
OPERATING DAYS PER YEAR
300
COST ASSUMPTIONS
Routine operating and servicing performed by normal ships crew
compliment.
Cost of installation 55$K.
Utilization of existing power and air supply.
Bulk purchase of consumables.
Cost of money excluded,
20 year system life.
2500 gal/day average waste water flow.
Sea water heads
Quantity production of system.
Figure 19,, Projected Annual Cost of System Operation
71
-------
TABLE 18. WASTE TEEATMENT SYSTEM FIXED COSTS
Estimated
Maintenance Material Cost
Items
Pumps $ 900
Incinerator shell 5,000
Electric motors 250
PSG overhaul 300
Blower 500
Controls and power supply 2,000
$8,950
$8, 950 20 year life = annual cost $447
Annual Overhaul Labor:
80 hours x $6/hr. 480
Amortization:
System purchase price $ 36,900
Installation 55,000
$ 91,990
$ 91,900 20 year life = annual cost $4,595
Total annual fixed cost $ 5, 522
72
-------
TABLE 19. WASTE TREATMENT SYSTEM OPERATING COSTS
Item
Electric power
Chlorine solution
Floe aid
Incinerator fuel
EC cell plates
Activated carbon
Maintenance
Consumption
Rate
7. 2 kwh/day
5 gal /day
2.5 Ibs/day
32 gal /day
600 hr/set
12.5 Ib/day
4 hrs/mo
Cos
Unit
Cost ($)
.015
.250
.230
.100
87.000
.260
6.000
st per day operation
Daily
Cost ($)
1.08
1.25
.57
3.20
1.30
3.25
.80
$ 11.45
Comparative Economics
The economic feasibility of this process depends not only on the ship owner's
ability to pay, but on the cost of alternative approaches. Since holding tanks
are a frequently considered alternative for shipboard waste disposal, the com-
parative costs of this alternative were developed and are compared on Figure 20.
Costs for holding are based on comparable ship type and crew size. The tank
was sized for seven days maximum hold and 45 gpm pump out. Twenty year
amortization of initial cost is assumed. A labor cost of $6 per hour is assessed
for pier side connection.
Shore side disposal, the major operating cost, is parameterized to reflect its
variable nature. At a cost of $2. 50/KG, an average pump out cost on Lake
Michigan (reference 8) the cost of treatment is 11 percent greater than that of
simple holding.
It should be recognized that the shore cost of treatment is highly variable (ref-
erence 9) and if a vessel must resort to barging or trucking water wastes, the
cost of transfer and treatment can increase by a factor ten. In view of the far
greater operating flexibility of the treatment system and the holding tank's de-
pendence on an uncertain availability and cost of shore side disposal, the apparent
small cost penalty incurred by treatment can be easily offset.
73
-------
Annual
Cost
($K)
12 -
10-
8-
6-
4-
2-
7,812
($6,182)
($ 6,932)
TREATMENT
($ 7,682)
I
1234
Shore Disposal Charge Dollars Per 1000 Gallons
Assumes 200 days/year operation
Figure 20. Comparitive Cost of Treatment vs. Holding
74
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SECTION VI
ACKNOWLEDGEMENTS
This program, which extended over a period of twenty-seven months, was ac-
complished by the dedication and cooperation of many individuals in govern-
ment agencies and the contractor organization. Due to the numbers of these
individuals only a few can be mentioned, however, the authors wish to express
their sincere appreciation to all contributors.
The support of the project by the Office of Research and Monitoring, Environ-
mental Protection Agency and the help and guidance provided by K. Jakobson,
Project Officer, is acknowledged with sincere thanks.
The officers and crew of the U.S. Army Corps of Engineers vessel Gerig were
especially helpful during onboard operations and in circumventing many com-
munication and logistics problems associate with working on board a ship at
sea. Capt. R. Boltin and Chief Engineer J. Owens were key people to this
successful operation.
The Corps of Engineers, Marine Design Division Phila., Pa., G. Johnson,
J. Magyarik, W. Brehmeyer; Jacksonville District, Plant Branch, M. V. Benzin,
P. Baumgardner; Operations Office, Washington, D.C., W. Murden were ex-
tremely helpful during initial design and installation and subsequent sea trials.
Cdr. A. Sterling U. S. Coast Guard, Washington, D.C. provided invaluable
assistance in insuring safe system operation and conformance to good marine
design practice.
The Cincinnati, Ohio Office of the Environmental Protection Agency provided
invaluable work and equipment for water chemistry analysis during a major
part of the sea trials. Mr. E. Raabe provided expert training for proper
analytical technique to General Electric personnel.
Dr. Brauer and the Wrightsville Marine Bio-Medical Laboratory provided
laboratory facilities at no cost during operations in North Carolina. Their as-
sistance is greatly appreciated.
The development, design, analytical work, and sea trials were performed by a
team from the General Electric Company, Re-entry and Environmental Systems
Division, the key members of which were J. C. White, Program Manager;
P. Shelley, Project Engineer; A. Bryce, Project Biochemist; D. Cheater,
Biochemical Analysis; E. Darrah, F. Milotich, J. O'Donnell, Ships Crew.
75
-------
SECTION VII
REFERENCES
I. Sacks, B. R. ; Extended Aeration Sewage Treatment on U. S. Corps of Engi-
neers Dredges. Federal Water Pollution Control Adm.. Cincinnati, Ohio,
January 1969
2. Weinberg, G. ; Results of Sewage Characterization Study Dredge "Gerig",
Interim Report to Environmental Protection Agency, Contract 14-12-522,
September, 1969
3. Farrell, R. P. ; Advanced Development of Household Pump-Storage-Grinder
Unit Task 6, FWPCA Contract No. 0614-12-29; Prepared for American
Society of Civil Engineers, Project on Separation of Combined Sewers,
Mr. M.B. McPherson, Project Director, December 1968
4. Tech. Manual; Water Purification Unit, Trailer Mounted, Electric Driven...
600 Gallons per Hour, Met-Pro Water Treatment Corp. , Lansdale, Pa.,
June 1968
5. Public Health Assoc,, ; Standard Methods for the Examination of Water and
Waste Water, 13th Ed. ; Prepared and published jointly by the American
Public Health Assoc. ; American Water Works Assoc., Water Pollution
Control Federation, 1971
6. Manual; Chemical Analysis for Water Quality Training Manual, Water
Quality Office, Environmental Protection Agency, February 1971
7. Weber, Walter J. Jr. ; Physicochemical Treatment of Waste Water, Journal
of the Water Pollution Control Federation, P83; Weber, Hopkins and Bloom,
January 1970
8. Turney, William G. ; Journal of Water Pollution Control Federation,
March 1971
9. Reynolds, Smith and Hills; Engineering Report on Shore Disposal of Ship
Generate Sewage at Activities in the Eastern Area, Naval Facilities Engi-
neering Command, Department of the Navy, Wash., D. C. , 203904, Contract
No. N00025-69-C-0004, June 1, 1969
77
-------
SECTION VHI
BOD
BODr
BOD,
COD
Colif.
Col./lOO ml
or
MPN Col./lOO ml
GPD
Depl.
P.O.
Eft.
Inf.
IOD
JTU
mg/1
QRP
PVC
Res. C12
Sol. BOD
s.s.
TOD
TOT BOD
GLOSSARY
Biochemical Oxygen Demand
Biochemical Oxygen Demand (2-day Analysis)
Biochemical Oxygen Demand (5-day Analysis)
Chemical Oxygen Demand
Coliform (bacteria)
Most probable number of colonies (of bacteria) per
100 milliliters (of sample)
Gallons per day
Depletion
Dissolved Oxygen
Effluent
Influent
Immediate Oxygen Demand
Jackson Tubidity Units
Milligrams per liter (same as ppm)
Oxidation-Reduction Potential
Parts per million (by weight)
Polyvinylchloride (plastic)
Residual chlorine
Soluble BOD
Supsended solids
Total oxygen demand
Total Biochemical Oxygen Demand
79
-------
SECTION IX
APPENDICES
A. Component Development Eeport for the Watercraft Waste Treatment System
B. Summary of Gerig SWTS Test Data
81
-------
INTRODUCTION
The General Electric Company, Re-entry
and Environmental Systems Division (RESD)
was awarded Contract 14-12-522 to develop,
build, and test a prototype shipboard waste
treatment based substantially on proposals
submitted to the FWQA in December, 1968 and
January, 1969. The contract was initiated in
May, 1969 and the component development
proceeded in accordance with the Program
Plan - Shipboard Water Pollution Control
Project, (Reference 1).
The objectives of this contract which
encompassed 22 months are: 1) develop an
operating shipboard waste treatment plant for
large vessels, 2) demonstrate success in meeting
high waste treatment standards, 3) operate for a
test period aboard a ship, and 4) perform an
evaluation of the function and economy of the
system. Intensive development effort was to be
spent on electrocoagulation as a technique for
electrochemically generating flocculants and
treating wastes.
The performance objectives established for
the prototype system have evolved since the
inception of the project. The resulting effluent
parameters are as follows:
Parameter
Objective
Biochemical oxygen ^50 ppm
demand
Total suspended -.jnimum complexity, weight, and
volume to be acceptable for shipboard. The
electrocoagulation approach was selected by the
General Electric Company because, unlike
biological treatment systems, it would be
relatively insensitive to the wide fluctuations in
influent composition and temperature that can
be expected aboard a watercraft. In addition, an
electro-chemical system can not be poisoned by
cleaning agents, acids, or bases.
The following description provides a brief
introduction to the watercraft-plant system
concept, functionally shown in Figure 1. The
components and the functions described
individually should not be construed to place
singular emphasis on any single component or
function. To understand the system rationale it
is necessary to grasp the significance of
component interdependence. Taken one step
further, it is likely that several of the
components could be combined in an advanced
system, even though the functions accomplished
in the prototype would still be required.
As shown in Figure 1, the sewage of
culinary, wastewater, laundry and sanitary origin
is piped to the Pump-Grinder, which provides an
aerated sewage storage capacity that smooths
out process operating cycles, that grinds the
sewage solids, and that establishes the constant
throughput flow to the treatment cell. In the
Electrocoagulation Cell, ferrous ions are
electrochemically generated by applying a d-c
potential to steel plates arranged in parallel. The
comminuted sewage and waste water are then
pumped in between the steel plates. Coagulation
of the ferrous ions and sewage is enhanced by
providing sufficient transport time in the cell.
83
-------
(VENT OUTPUT)
BLOWER
VENT (CHLORINE)
INFLUENT SEWAGE
PUMP GRINDER
SEWAGE BY-PASS
1 . Surge Tank
2. Chlorine Sol
3. Relief Valve
4. Floe Aid Storage
3 OVERBOARD *
T-TP^"
I I
2
1 t VENT (H-,1
J
E
5G)-^Vk
i
t
ution Stora
jrage
FT
U
ge
| L
1
ty<
T i : i *
i |
1 1 4
1 L
1 i c^a \ t^i A a
1 \ Q5
IELECTROCOAGULA'
1 CELL
i 1
i i
AIR & FOAM & H2 i
PG OVERFLOW '
o
' 10
i
1
*- _*.
! 9O9
ill" ^ t " I
;"" ' V | , EFFLUENT
pi UUALIIY
6 M MONITOR
\ /MH 8 .'""^> (EFFLUENT
\ / [7 | i x OUTPUT)
IUN % ! I f rป TA t CHLORINATED H n
1
^. UPPER (a^h ^ VENT OVERBOARD
DECK ^-^ I
11 I '
r^l ^ % ป
?! *. -?U ซ~J^ FUFI.IN
5. Floe Aid Pump 9. Chlorine Pump 13. Sludge Holding Tank
6. Upflow Clarifier 10. Recycle Pump 14. Incinerator
7. Recycle Pump 11. Sludge Storage Tank 15. Emergency Pump (53 gpm)
8. Chlorinator Tank 12. Sludge Withdrawal Pump 16. Chlorinated H2O Pump
Figure 1. Watercraft Waste Treatment System Schematic
Flocculation of these particles to form larger
aggregates capable of separation by
sedimentation is accelerated by the rapid mix of
the agitator in the Upflow Clarifier. The sludge
is transferred and concentrated by pumping it
into the sludge storage tank where it is
periodically withdrawn for incineration. The
clarified effluent from the clarifier is disinfected
and pumped overboard without any harmful
effects to the body of water in which the ship is
travelling.
In summary and based heavily on the data
presented in this report and on those data from
the many tests not presented here because of
space limitations, it is concluded that
physical-electrochemical treatment is the best
solution to waste treatment on ships. Conclusive
data on alternate systems performance are not
readily accessible, but inherent advantages of the
physical-electrochemical may be postulated.
Unlike aerobic treatment the prototype plant is
capable of rapid start and shutdown, is free from
effects of salinity and hydraulic gradients, and
permits significant size reductions. Continued
development of the prototype concept is
recommended and should be concentrated on
simplification and component performance
improvements.
COMPONENT DEVELOPMENT
DEVELOPMENT BACKGROUND
It was noted in the introductory statements
to this report that the Re-entry and
Environmental Systems Division proposed to
develop a watercraft waste treatment system
based on experimental work performed at the
General Electric Research and Development
Laboratory. Sufficient laboratory scale results
existed to warrant further development of
shipboard components.
Based on a waste treatment process
utilizing electrocoagulation and solids
separation, key components of a system were
84
-------
identified. The project program plan (Reference
1) then established a component development
schedule summary which is given in Figure 2.
Such a plan does result in a system comprised of
individual components because development
units were subsequently used at the system level.
Therefore, there exists ample opportunity for
combining components and for decreasing the
volume of this first system in later
configurations.
In retrospect, it can be said that the
resulting system was essentially designed from
the ground floor up. A thorough review of
existent test data and early test results at G-E
RESD with electrocoagulation, required that
company funds be allotted for basic cell
development and characterization.
At the start of this project the solution to
the problem of sludge disposal was to store it for
convenient disposal later. This concept seemed
viable at contract inception since incineration
was straightforward. During the project,
investigation revealed that sludge burning
incinerators for shipboard were not generally
available. Agreement was then reached with the
FWQA to alter the project scope to include
refurbishment of a government-furnished
incinerator. The unit proved to be incapable of
refurbishment. An incinerator is being developed
with company funds and will be available for the
shipboard demonstration.
PUMP GRINDER
All sewage generated on a ship is piped to
the Pump-Grinder, which functions to provide
storage volume, so that the operation of the
system can be smoothed out into a fewer
number of cycles and for purposes of
comminution of solids into colloidal sizes for
pumping into the Flectrocoagulation Cell.
Comminution of the sr.ids in wastewater assures
maximum particle surface area, as this is critical
to the success of the coagulation process.
Comminution also permits the use of small
diameter pipe and minimum interplate flow
passages, permitting in turn lower d-c voltage
operation of the cell.
To achieve reduction of solids to less than
0.25 in. diameter, a developmental component
built by the General Electric Company for the
American Society of Civil Engineers under
FWPCA Contract 14-12-29 was transferred to
this project. This unit utilizes grinder technology
accumulated by the General Electric Company
in the manufacture of household and
commercial grinders.
TASK
Pump Grinder \
J
7
A S
-&
r?
1969
0
/
N
\
D
1
J F
1
1
M
1970
A M J J A S
I
i
1
O N D
Electrocoagulation Cell Phase II
Electrocoagulation Cell Phase III
ClarifierGl Test
Clarifier G2 Test
ClarifierGSTest
Motion Simulation
Control System
V A
VA
^&
^7 - A
Figure 2. Component Development Schedule Summary
85
-------
The unit, before modification, is shown in
Figure 3.
A similar Pump-Grinder developed by G.E.
Co. for the Combined Sewer Separation Project
of the ASCE was successfully adapted for use in
the watercraft application. The laboratory unit
has been redesigned to accommodate three times
the sewage capacity, has had new sealed bearings
installed, has a new control system, and has
incorporated upgraded components for
operation in seawater. See Table 1. A duplicate
unit was built to conduct an endurance test, and
with the upgraded hardware, 1000 hours of
sewage operation were successfully completed
TABLE 1. PUMP GRINDER SPECIFICATIONS
Part
Characteristics and/or part number
Motor General Mectric Model 5Kf47RG9l 3U
I IIP, I 725 rpm, capacitor start, single
phase
Power I 15 VAC, 10 a, 60 Ilx
Pump Moyno TS44 with rotary seal
Upper PC bearing Scalmaster 64522-PS3 IL-1 2}
Lower PG bearing Uclco New Departure Z99R 1 2
Figure 3. Household Pump Grinder
86
-------
CONSIDERATIONS IN ALTERING
PUMP-GRINDERS
Use of the unit shown in Figure 3 was
considered because the essential features of a
shipboard Pump-Grinder already were present in
this component, and project economy could be
realized if tests of the altered Pump-Grinder in
seawater were successful. The first unit was
conceived as a solution to the peakloads
generated in a typical household of four persons.
The tank volume had a capacity of 55 gallons
and a discharge flow of 15 to 11 gallons/minute
for 0 to 35 psi. The use of a modified G-E
Hotpoint commercial grinder in the
configuration chosen assured that all sewage
would be comminuted before discharge and that
heavy objects would fall harmlessly to the
bottom of the tank for cleanout at a later time.
The following paragraphs present the
considerations and alterations made in adapting
this hardware, as shown in Figure 4, for use in
watercraft. The considerations made were on
establishing flowrate, determining aerated
storage volume, running an endurance test, and
establishing emergency passages.
PUMP ON
29.4 GAL
PUMP~
OFF
32 IN.
7-3/4 IN.
55 GAL ENVELOPE
150 GAL ENVELOPE
Figure 4. Watercraft System Pump Grinder
a. Establishing Flowrate. The
Pump-Grinder utilizes a double-ended shaft AC
motor which drives the inverted grinder flywheel
directly and drives a progressive cavity pump
through a belt drive. The key factors which are
determined by the selected system flowrate are
the required storage volume of the
Pump-Grinder, the power and plate area
required in the Electrocoagulation Cell, and, of
paramount consequence, the volume of the
Upflow Clarifier. Of the factors considered, the
detention time of one hour in the clarifier,
weighed against the increase in storage required
in the Pump-Grinder if flowrate was reduced,
caused a flowrate of 5 gpm and a clarifier
volume of 300 gal to be selected as a suitable
compromise. (See Figure 5.)
b. Determining Aerated Storage
Volume. The Pump-Grinder tank volume was
established by examining the hydrograph
determined for the ship, Dredge Gerig, in the
wastewater quality and flow survey performed
in August 1969 (See Reference 2). The
hydrograph is reproduced here as Figure 6. The
peak-sewage-influent flow occurred at 1612. The
method of data accumulation measured the
effluent pump on/off cycles from the existent
plant. An on/off cycle for this pump occurred
when 80 gal was received. Table 2 presents the
sewage accumulated in the peak period in
tabular form. The system flowrate used to
establish the total accumulation in the tank was
5 gpm.
To arrive at a suitable tank volume it
is necessary to include an additional 79 gal since
this is a surge influx which could, because of the
measurement technique, be missed. Therefore,
1 50 gal capacity was selected.
c. Running an Endurance Test. A
duplicate Pump-Grinder was fabricated with
G.E. Co. funding and was subjected to extensive
tests. No difficulty was encountered when
plastic spoons, cloth and disposable diapers,
sanitary napkins, sand, and filter cigarettes were
processed. After 90 hours of test, excessive
bearing noise was noted. Disassembly of the unit
87
-------
revealed that weepage of wastewater by the
shaft seal into an unsealed bearing caused loss of
lubricant and rough operation. Replacement of
the lower bearing by a sealed bearing permitted
1000 hours of successful operation.
TABLE 2. CALCULATED PEAK FLOW TO PUMP GRINDER
Time
Time
(minutes)
PC
output
in AT
(gallons)
Input
minus
output
(gallons)
Total
Accumulation
(gallons)
1612
1621
1634.3
1643.2
1708.2
1732.5
45
35
35
13.3
9.85
25
24.3
66.5 13.5 48.5
49.25 30.75 79.25
125
45
34.25
121.5 41.5
NOTES: Data is from Dredge Gerig survey (Reference 2).
Input volume was 80 gallons before pump-out.
The PG rate is 5 gal/min.
8
1 6
1 4
LL
2
0
C
MO
1
I
YNO PUMP
FS44 580 RPM
'--- ~-_
.
) 10 20 30 40 5C
DISCHARGE PRESSURE, psig
Figure 5. Pump Grinder Flow vs. Pressure
d.. Establishing Emergency Passages. An
overflow sensor was incorporated so as to
indicate influent sewage flow through the
protective barrier screen and overflow pipe
connected to the Sludge Storage Tank. This was
an emergency provision to divert influent, in the
event of Pump-Grinder overflow, directly into
the sludge tank. An indication of overload of the
sludge tank will cause pump out from this tank
at the rate of 52 gpm. A relief valve and bypass
line downstream of the pump provide protection
against overpressure in the cell.
ELECTROCOAGULATION CELL
The primary function of the
Electrocoagulation Cell is to generate ferrous
hydroxide coagulant for waste treatment. This is
done electrically by applying a d.c. voltage to
mild steel plates. Electrocoagulation can be
appreciated when the following features of the
complete system are understood:
a. Startup and shutdown of the system is
immediate because only flow and power need be
initiated
b. Trained personnel are not needed or
required to establish and reestablish system
operation after shutdown.
c.. Constant current control assures
independence of effects from wastewater
salinity level.
d. Rapid but thorough exposure of
sewage solids to the coagulant is inherent to the
cell design.
e. Attendant reduction in contaminant
level can be attributed to electrolysis and
oxidation/reduction.
When a logically made comparison is made
with chemical coagulation, electrocoagulation
results in a shorter processing time and greater
reduction of pollution contributing constituents
in the effluent.
Experimentation in treatment of municipal
wastes by electrocoagulation was reported by
the General Electric Research and Development
Center, Schenectady, N.Y. (R&DC), for a period
88
-------
a
O
UJ
O
<
(C
UJ
<
y
3
2
24
SANIT
WASTI
00 0200
ARY, GAI
=S FOR 5C
-LEY, ANC
MEN
"T-i
- BREAK
) LAUNDR
PI
Jl
C ACT 1
t It
Y
f
"-i_J
LUN
T-H
I It
0400 0600 0800 1000 1200
TIME, hours
1
r
U
DINN
t
n
CR -
1 400 1 600 1 800
2000
2200 2400
Figure 6. Wastewater Hydrograph in the Dredge Gerig
from 1966-1968. Sufficient test data were
obtained to show that significant reduction in
BOD, in total suspended solids, and in turbidity
was achieved when jar test settling or
centrifugation followed cell treatment.
A cell, reported in an R&D Center test
report, and which was used for the batch
treatment of four gallons of sewage is shown in
Figure 7 A more advanced electrocoagulation
cell used in field test is depicted in Figure 8.
Examination of this photograph shows that the
cell was open at the top and a series of skimmers
were required to remove foam.
It was recognized that substantial
engineering remained to transform these
laboratory units into shipboard suitable
components. The Statement of Work for the
project directed, therefore, that major system
development emphasis be devoted to
optimization of the electrocoagulation
treatment. It is quite logical, then, that initial
development work was primarily engineering.
The aspects of electrocoagulation studied
included:
plate geometry
a. Cell
flow paths,
b. Power requirements,
c. Foam and floatable disposal,
and wastewater
d. Safe gas venting, and
e. Solids accumulation removal.
The development plan for tin.'
electrocoagulation cell was conceived on the
assumption that sufficient data existed to enable
the design of a watercraft cell. A reassessment of
this approach was required when initial tests at
REst) with seawater wastewater yielded a
floating floe. These poor results did not agree
with results reported for the cell depicted in
Figure 8. The reason for the gross performance
difference became clear upon closer review of
earlier R&DC data which was gained by doping
municipal wastewater with common salt. For
reasons explained fully in later text, sea water
which contains magnesium, calcium, and
potassium salts in addition to small percentages
of others, drives the pH substantially below the
optimum for ferrous hydrated oxide
precipitation.
The upshot of these findings was a
reevaluation of the content of the
electrocoagulation cell development program. In
view of the basic nature of these initial
conclusions, GE Co. sponsorship of a plan to.
characterize the electrocoagulation cell with
respect to critical parameters was obtained.
Although not originally conceived as a task
comprised of several building blocks, the
89
-------
7. /?. and D.C. Electrocoagulation Cell for Batch Tests
Figures. R. and D.C.
Electrocoagulation Cell
Used for Field Tests
90
-------
development of a watercraft electrocoagulation
cell was performed in three phases:
Phase I. Characterization of the cell with
a range of influents
Phase II. Evaluation of flocculent aids in
sea water
Phase III. Biochemical performance with
sewage
Electrocoagulation as a key feature of the
prototype watercraft waste treatment system
has conclusively proved its merits. Some of the
important attributes of a watercraft system
incorporating electrocoagulation are 1) rapid
startup after shutdowns, 2) freedom from
adverse effects of hydraulic and wastewater
salinity shocks, and 3) when combined with
effective flocculation and separation of solids,
results in treatment of the watercraft sewage so
that effluent characteristics exceed the project
goals as follows:
Characteristic
Goal
Effluent Parameter
Biochemical Oxygen Demand
-------
TABLE 3. ELECTROCOAGULATION CELL SPECIFICATIONS
Configuration
Gl
G2
G3
Housing material Plexiglas-G Plexiglas-G
Epoxy
Fiberglas
No. of plates
Plate thickness
Area of plates
Volume of cell
Flow volume
Wt. of iron
Hydraulic radius
Reynolds No.
Flowrate
Current
Current density
Scrubbing jets
Air pressure
Nozzle diameter
8
0.5 in.
7
21.8 fr
1.92 ft3
1.37ft3
270 Ib
0.45 in.
8780
2 gpm
70 amp
6.4 amp/ft2
--
16
0.25 in.
7
48.2 fr
1.92ft3
1.37 ft3
268 Ib
0.47 in.
8440
5 gpm
175 amp
7.2 amp/ft2
4
40 psig
.040 in.
16
0.25 in.
9
51.3 ft
1.85 ft3
1.3ft3
271 Ib
0.47 in.
8440
5 gpm
175 amp
6.8 amp/ft2
19
5 psig
0.125 in.
NOTE1. Plate material in each cell was cold-rolled steel
type 4130.
b. Power Requirements. On board a
vessel the electrocoagulation cell requires a d.c.
voltage supplied to alternate plates so that the
rate of ferrous ion generation can proceed in
accordance with Faraday's Law. The watercraft
system converts the 440 vac 3 phase to d.c.
voltage and provides constant current control to
the cell.
It was found that power consumption is
affected by the electrocoagulation cell spacing
and the conductivity of the wastewater. Since
cell spacing was established at 0.5 in. because of
comminuted sewage considerations, only the
effect of wastewater changes in conductivity will
be of consequence. The voltage required to
maintain the desired 175 amp level is shown in
Figure 1 2 for varying conductivity.
Note that for brackish wastewater, most
likely the norm on the Dredge Gerig, the voltage
is 5 at 95 percent efficiency in the cell power
supply, the power required is 0.92 KVA.
c Foam and Floatable s
Disposal. Measurements made of the solids
content of the foam generated in the
electrocoagulation cell revealed the desirability
of diverting the foam for .disposal by
incineration. Because there is some hydrogen gas
trapped with the foam, safe venting of the
hydrogen requires that the hydrogen be released.
Several approaches were taken with the
foam. The first approach was to permit passage
of the foam to the rapid mix chamber of the
clarifier and thereby vigorously release the
entrapped gases. This approach did not work
because the foam tended to buoy up the sludge
blanket forming in the clarifier. A simpler tack
was attempted by adding a silicone defoaming
agent at 100 ppm to the Pump-Grinder. The
foam was not inhibited by addition of the agent.
A third alternate attempted was the conveyance
of the foam from the cell directly to the sludge
storage tank. However, the foam occupied
significant volume intended for greater density
sludge, and the foam left to its own course was
extremely stable. The final refinement shown in
Figure 13 was the incorporation of a
sludge/foam recycle circuit utilizing a pump and
ejector. By passing the contents of the tank
through the ejector, dual functions are served.
First the foam is separated from the entrapped
gases and vented; second, the foam is withdrawn
from the cell by the suction established in the
ejector.
d. Safe Gas Venting. Hydrogen is evolved
at the eight cathodes in the electrocoagulation
cell by the electrolysis of the conductive
wastewater. Since it is likely that the shipboard
waste treatment system will operate in a ship
compartment, it is essential that the gas be
safely removed. The rate of generation of the gas
for varying applied currents is shown in Figure
14. For the current level established in the
prototype system, 175 amp, approximately 0.04
are generated.
92
-------
By diluting the hydrogen in an air flow of
200 ft3/min maintained by a Rotron, K5508,
Squirrel Cage Blower, the gas mixture can be
kept safely below the lower explosive limit, 4
percent, of hydrogen. Two aspects of the
venting scheme need further
clarification: l)the blower outlet port has
mounted to it a venturi which establishes a net
suction on the hydrogen, 2) there is
incorporated in the cell a sensor which inhibits
power to the cell when the cell is not full of
wastewater.
The venting configuration discussed was
approved for certification by the U.S. Coast
Guard.
e. Solids Dislodging. Because the system
can be started up and shut down rapidly, there is
a likelihood of solids settling of the wastewater
contents in the cell. To eliminate buildup of
these solids, air flushing was tested in the G2
configuration and adopted in the G3
configuration. Air flushing was selected in favor
of water flushing, because the air could be
conveniently vented after its scrubbing function.
This was not the case with the flushing water,
because this would impose an additional load on
the clarifier. The air flush is planned for each
hour of operation.
Polarity reversal for the purpose of
alternating anodes and cathodes is planned for
once a week. This will assure uniform wear of all
plates.
Figure 10. G2 Electrocoagulation Cell, Internal and External Views
93
-------
20 K
Figure 11. G 3 Electro coagulation Cell With
Fibreglas Case
10 15 20 25 30
ECC VOLTS, d.c.
Figure 12. ECC Power vs. Wastewater Con-
ductivity, Constant Current of 175 amp
VENT DUCT
BLOWER
n
1
/
MAKEUP AIR
N
\
HYDROGEN
SLUDGE STORAGE TANK
ELECTROCOAGULATION
CELL
RECYCLE PUMP
Figure 13. Foam Separation Cycle
94
-------
.05
.04
I -03
ui
$
K
.02
.01
100
CURRENT, amp
200
Figure 14. Hydrogen Gas Generation vs.
Applied Current
ELECTROCOAGULATION CELL TEST
PROGRAM
a. Phase I Description. Phase I tests had
as an objective the determination of the critical
parameters affecting electrocoagulation. The
evaluation of the cell was carried out by
operating with influent wastewaters of
increasing complexity in composition. By
approaching the study in this fashion, those
waste characteristics which influence the cell
operation could be studied independently. The
influent materials consisted of the following
tested in the order presented:
1. Tap Water + 1.25% sodium chloride
(NaCl)
2. Tap Water+ 2.7% NaCl
3. Tap Water +1.25% NaCl + Magnesium
Salts
4. Tap Water + 1.25% NaCl + Magnesium
Salts + Calcium Salts
5. Natural Sea Water
6. Brackish Water 50% Seawater + 50%
Tap Water
7. Brackish Water + Simulated Sewage
b. Phase I Results. The Gl
configuration electrocoagulation cell was found
to have a natural operating pH of 9.5 to 10.5
when the influent was fresh water containing
NaCl. This is very nearly an optimal range for
iron flocculation with ferrous hydroxide. The
pH level is maintained due to the presence of
hydroxyl ions which are generated in the
electrolysis of water. Maintenance of the current
density in water with NaCl required low
voltages. When magnesium and calcium salts are
added to simulate seawater, the pH of the
effluent is driven down to the 7 to 8 range. This
is attributed to the formation and precipitation
from solution of magnesium and calcium
hydroxide. When natural seawater was treated in
the cell, the pH of the effluent was driven down
to 6.2 and the resultant floe was poor. Figure 15
shows the effect on effluent pH of the influents
tested.
10
lj
1
1
1?
F/
x;
f
~~~^ ^
o .
\
\
J 1 I
__- -H L L
---1
~ SIM
O NA
-C
\
\
^
- - 1 .2!
= - NA
^-o.
^a
x
J\
\
ULATEDSEA
CL + MG SALTS
% NACL
5% NACL + TAP
TURALSEA WA
O .
^
O 1
. ^.
H20
TER
.
10 15 20 25
TIME, minutes
30
35
Figure 15. Effect of Dissolved Salts on
Effluent pH
Recognizing that the pH would require
raising, a series of tests were run utilizing
simulated sewage and brackish wastewater.
Brackish wastewater was made by diluting
seawater with 50 percent fresh water. The
current was adjusted to 35 amp/gpm flow, a
value which introduced the optimal value of
from 40 to 50 ppm Fe++ Figure 16 presents the
total iron content in the effluent as a function
of applied current. The tests were run at 2 gpm
95
-------
to permit a reduction in current density since it
was suspected that turbulence due to evolved gas
in the Gl eight plate cell was disrupting
coagulation.
FERROUS IONS, mg/liter
10 A 0> 00 (ฃ
0 0 0 0 0 C
/
X
/
/
/
/
/
10 20 30 40 50
CURRENT/FLOWRATE, amps/gpm
60
Figure 16. Fe++ vs. Current per Gallon per Minute
Samples of the cell effluent were
withdrawn for flocculation using a flocculent aid
Percloron, a tradename by Pennwalt Chemical
Co., Percloron (calcium hypo-chlorite) was
evaluated because, if successful, it had the
twofold advantage of raising the pH and
simultaneously chlorinating the effluent.
However, Percloron was not able to increase the
pH at the recommended usage level because of
the buffering capacity of the mixture. The pH of
the effluent samples ranged from 6.6 to 7.3.
Reductions in total oxygen demand (TOD) of
the treated material were as high as 86 percent.
However, flocculation was poor due to the low
pH. In order for optimum flocculation, when
the cell was processing sea water it was necessary
to raise pH of the effluent by adding base
(NaOH). The best flocculation occurred at pH
11. However, it was decided to operate at pH
10. Due to the buffering capacity of the sea
water, it required 10 times as much base to raise
the pH from 10 to 11 as it did to go from pH 6
to 10. The flocculent aid tested markedly
decreased the solids settling time.
Bacterial colony counts of the
unchlorinated effluent indicated a one log
decrease in total viable organisms from 8x10
to 4 x 105. Since only insignificant amounts of
residual chlorine were detected it can be
assumed that the reduction in bacterial
population was due to a combination of
flocculation and electrolysis in the cell.
Because of an increase in average TOD
measured in the last four effluent samples in
Table 4, it was assumed that a homogeneous
influent mixture was not being assured. The
results presented in Table 5 were obtained after
a stirrer was added to the influent holding tankto
assure a constant composition influent for the
test.
The effluent from the test tabulated in
Table 5 was also titrated with sodium hydroxide
in order to establish the amount of base required
to reach the optimal pH range. The results are
shown in Table 6.
c. Phase I Conclusions. The
conclusions reached in test of the Gl
configuration electrocoagulation cell follow:
1. The electrodes should add 40 to 50
ppm of iron to the waste for optimal
flocculation. In the present configuration a
current input of 35 amp/gpm is required.
Efficiency of iron addition falls off due to
coverage of the electrode surfaces by ferric
hydroxide and precipitated sewage. The 35-amp
setting has maintained the required iron levels
over the evaluation period.
2. Operation in brackish or seawater
requires the addition of hydroxyl irons to the
effluent in order to provide suitable floe
formation. The natural operating pH for the EC
process in sea or brackish water is in the 6 - 7.5
range. This is an ideal range for aluminum
flocculation. It would be advisable to study an
EC cell containing aluminum electrodes for use
in this environment.
3. The cell has the capability to remove
80 to 95 percent of the oxygen demanding
material from the simulated sewage. This
occurred whether the total oxygen demand
of the influent was 500 to 2000 ppm.
96
-------
TABLE 4. PHASE I TEST RESULTS - G1 CELL, BEFORE STIRRING
Sample
pH
Conductivity
(H mho/cm)
Turbidity
(JTU)
Dissolved
iron
(ppm)
Settleable
solids
(ml)
TOD
(ppm)
Alkalin-
ity
(ppm)
Calcium
hardness
(ppm)
Ortho
phospate
(ppm)
Residual
chlorine
(ppm)
Influent sewage^ '
Flocculated effluent^
(Stirring only)
Flocculated effluent^-*
(Purifloc A-25-5 ppm)
Flocculated effluent
(Percloron-1.4 ppm)
Flocculated effluent'
(Percloron-2.8 ppm)
Flocculated effluent1
(Percloron-4.2 ppm)
(2)
(2)
(2)
7.8
6.6
7.0
7.0
7.1
7.3
18,500
19,000
19,000
19,000
19,000
19,000
43
20
23
17
17
17
1
5
3.5
3.5
3.5
3.5
22
24
--
23
--
420 1500 535
70 525
Flocculated effluent^2'
(Percloron 20 ppm)
Flocculated effluenr '
(Peicloron 30 ppm)
Flocculated effluent^
(Percloron 40 ppm)
Flocculated effluent' '
(Stirring only)
7.2
6.6
6.8
6.8
25
26
10
11
8 22
74
64
64
60
78
74
78
78
535
520
530
535
0.6
0.3
0.1
0.1
0.1
0.1 0.1
0.1 0.1
0.1
^ ' Influent = 50 percent sea water + 50 percent tap water, synthetic feces, synthetic urine, salad oil and toilet paper. Total volume
processed = 100 gal.
Decanted supernatant after 2 minutes of mixing at 80 rpm, 30 minutes at 10 rpm, and 30 minutes at 0 rpm.
TABLE 5. PHASE 1 TEST RESULTS - G1 CELL,
AFTER STIRRING
Sample
PH
Dissolved
iron
(ppm)
TOD
Reduction
TOD
(percent)
Influent sewage(1) 8.2 2125
Flocculated effluent(2) 6.8 8 95 96
Flocculated effluent(2) 7.2
(20 ppm Percloron)
Flocculated effluent '
(30 ppm Percloron)
7.2
95
108
96
95
TABLE 6. BASE TITRATION OF G1 CELL EFFLUENT
Sample
NaOHtopH 10
(ppm)
Na OH to pH 1 1
(ppm)
NOTES:
^Influent - 50 percent sea water + 50 percent tapwater,
synthetic feces, synthetic urine, salad oil, and toilet
paper.
^Decanted supernatant after 2 minutes stir at 80 rpm,
30 minutes stir at 10 rpm, and 30 minutes at 0 rpm.
600 ml of deionized water 18
+ 30 ppm Fe
600 ml of sea water 300
+ 30 ppm Fe
600 ml of sea water 145
+ simulated sewage
180
2960
1450
97
-------
The TOD of fresh, raw, sewage is on the order of
200 ppm. The proposed allowable maximum for
effluent TOD is 50 ppm thus the cell should be
able to treat raw sewage quite effectively.
4. Periodic sludge buildup in the cell
probably curtails its overall operating efficiency.
A sludge removal device should be incorporated
as an integral part of the cell.
5. Flocculation at pH 10 (by addition of
NaOH) with the addition of Purifloc A-23,
(tradename of Dow Chemical product),
coagulation aid (5 ppm), will be considered a
standard condition. Other additives will be
evaluated with respect to these conditions.
d. Phase II Description. The Phase I
tests which utilized the Gl configuration
electrocoagulation cell did establish key
operating parameters for the cell. Phase II tests
were run with a completely revamped internal
configuration identified as the G2 cell. The
requirement for a flocullent aid to accelerate
flocculation and settling was identified in Phase
I. Particular emphasis was placed on evaluation
of the effectiveness of the flocculent aids in
seawater. The evaluated candidate aids identified
by their tradenames are as follows:
Purifloc C-31 (The Dow Chemcial Co.)
Purifloc C-32 (The Dow Chemical Co.)
Primafloc C-7 (Rohm and Hass Inc.)
Purifloc A-23 (The Dow Chemical Co.)
Sodium Hydroxide
Calcium Hydroxide
Sodium Aluminate (Betz Laboratories)
Nalcolyte 673 (Nalco Chemical Co.)
Nalcolyte 671 (Nalco Chemical Co.)
Separan NP10 (The Dow Chemical Co.)
Purifloc N17 (The Dow Chemical Co.)
Measurements were performed in this phase
to evaluate the reduction of phosphate and
ammonia nitrogen.
Use of the G2 configuration permitted
testing at the proper system current density and
flow rates. All test data obtained from this point
on were obtained at 5 gpm and 35 amp/gpm.
Q. Phase IIResults. Initial test results of
the G2 configuration cell utilizing simulated
sewage and brackish waste water are shown in
Table 7. The test was run with the same influent
as that of the Gl tests tabulated in Table 5.
Three candidate flocculent aids were selected for
use in the system; Purifloc A23, Primafloc C7
and Separan NP10. The three each give floe of
slightly different properties but all meet the jar
test criteria of significant reduction in turbidity
and suspended solids in one hour or less.
The electrocoagulation process was found
to be quite effective in reduction of influent
phosphate levels under the test conditions. (See
Tables 8, 9, and 10.) Phosphate can be found as
an insoluble precipitate in the presence of
calcium and magnesium ion. The reduction
should therefore be studied in fresh water
environments in order to determine the
effectiveness of the cell alone. A parallel test was
run using chemical flocculation only. The
effluents resulting from iron flocculation
contained three times the total phosphate of the
EC processed samples. The influent sample
treated with aluminum had the same degree of
phosphate reduction as the EC processed
samples.
Limited evaluation of ammonia reduction
was performed. The test results were variable. It
was demonstrated, however, that the
electrocoagulation process has the capability of
ammonia removal under a given set of
conditions (See Tables 8, 9, and 10). Additional
lab testing is required to establish the parameters
for optimal ammonia removal.
Electrocoagulation effected an 80 to 93
percent reduction in total oxygen demand
(TOD) of simulated sewage. TOD reduction for
raw in-house sewage ranged from 48 to 77
percent. The lowering in reduction is due to the
larger amount of soluble TOD in freshly
collected sanitary and culinary waste. A study
was initiated in order to establish the
relationship between TOD and biochemical
oxygen demand (BOD). Knowledge of the
influent BOD would establish whether
electrocoagulation could achieve the target value
of a 50 ppm maximum effluent BOD when
treating fresh, watercraft type of waste material.
A typical run was made with freshly collected
98
-------
TABLE 7. PHASE II INITIAL TEST RESULTS - G2 CELL
Sample
Dissolved
iron
(ppm)
Turbidity
(JTU)
TOD
(ppm)
Reduction
TOD
(percent)
Bacterial
(coliform)
Influent sewage*1' 50 1950 1 x 104
Flocculated effluent*-' 1.2 7 154 92 0
colonies
(total)
7x 105
0
pH 10
Flocculated effluent*2'
Purifloc 1.25 ppm
pH7
Flocculated effluent
Purifloc 2.5 ppm
pH7
Flocculated effluent
Purifloc 5.0 ppm
pH7
Flocculated effluent
Purifloc 7.5 ppm
pH7
Flocculated effluent'
pH7
(2)
5.0
3.8
* '
(2)
(2)
3.8
20
16
15
15
106
145
150
169
95
93
92
91
4.8xlOJ
4.3x
1.5 x 10J
NOTES:
(1)
(2)
Influent = 50 percent sea water + 50 percent tap water, synthetic feces, synthetic urine, salad oil and toilet paper.
Decanted supernatant after 2 minutes stir at 80 rpm, 30 minutes stir at 10 rpm, and 30 minutes at 0 rpm.
TABLE 8
Sample
Influent sewage
Flocculated effluent*- ^
Flocculated effluent*-1'
Flocculated effluent*-1'
Flocculated effluent^ '
Flocculated effluent*1'
Flocculated effluent* '
. G2 CELL TEST RESULTS - AMMONIA N AND PHOSPHATE REDUCTION
Ammc
Flocculent nitro
(ppm) (ppr
47
None 6
Adjusted to
pH 10
5 ppm A23 6
5 ppm C7
5 ppm NP 10
5 ppm
Nalco 673
)nia Total
;en phosphate
n) (ppm)
27.5
0.4
0.5
0.5
0.5
0.6
0.8
Ortho phosphate
(ppm)
11.7
0.3
0.25
0.3
0.3
0.27
NOTE:
Decanted supernatant after 2 minutes stir at 80 rpm, 30 minutes stir at 10 rpm, and 30 minutes at 0 rpm.
99
-------
TABLE 9. G2 CELL TEST RESULTS - AMMONIA N AND PHOSPHATE REDUCTION
Sample
Influent sewage
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
NOTE:
Flocculent
(ppm)
no flocaid^ '
1 ppm NP10(1)
2.5ppmNP10(1)
5.0ppmNP10(1)
7.5 ppm NP10(1)
10.0 ppm NP10(1)
Ammonia
nitrogen
(ppm)
18
20
18
20
12
12
12
Total
phosphate
(ppm)
12.5
0.5
0.4
0.2
0.1
0.2
0.4
Orthophosphate
(ppm)
4.0
0.2
0.1
0.1
0.1
0.1
0.1
^Decanted supernatant after 2 minutes stir at 80 rpm, 30 minutes stii at 10 rpm, and 30 minutes at 0.
TABLE 10. G2 CELL TEST RESULTS - AMMONIA N AND PHOSPHATE REDUCTION
Sample
Influent sewage
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
Flocculent
No floe aid
.08% Na-aluminate
.16% Na-alum.
.25% Na-alum.
.33% Na-alum.
.57% Na-alum.
Ammonia
nitrogen
(ppm)
10
10
10
10
10
10
10
Total
phosphate
(ppm)
15.0
1.2
.1
.1
.1
0.3
0.3
Orthophosphate
(ppm)
10
0.4
.1
.1
.1
.1
.1
sanitary waste. The data is presented in Table
1 1. The average effluent BOD had an absolute
value of 53 ppm even though the BOD reduction
was only 50 percent of the influent value. With
terminal chlorination the BOD can be reduced
below 50 ppm.
f. Phase II Conclusions. Data obtained
with the 8 electrode system can be validly
projected to the 16 plate system.
The data indicates that the 16 plate cell
(G3) performs similarly to the 8-plate cell with
respect to TOD reduction. The cell was
de-sludged and cleaned with a sulfamic acid
solution. The total iron generated at 35
amp/gpm was 100 ppm immediately after
cleaning but decreased to 50 ppm. Further
testing of the 16-plate cell will be conducted
using actual raw sewage consisting of in-house
culinary and sanitary waste. In view of the data
from the Dredge Gerig it is also advisable to
measure the ability of the system to treat
watercraft waste; perferably from the Dredge
Gerig. Additional bench testing will be
performed in order to evaluate the TOD
100
-------
NOTE:
TABLE 11. G2 CELL TEST RESULTS - BOD AND TOD
Sample TOD
(ppm)
Influent sewage 400
Effluent liquor (no floe aid)(1) 174
Effluent liquor (pH 10)(1) 160
BOD Total suspended
(ppm) solids (ppm)
115 239
50 11.8
56 21.0
Fixed
solids (ppm)
40.6
5
5
Decanted supernatant stirred at 80 rpm for 2 minutes, 10 rpm for 30 minutes, and 0 rpm for 30 minutes.
reduction by standard chemical flocculation
methods. Limited data indicates that chemical
flocculation (in one case) reduced the influent
TOD by approximately 40 percent. The EC cell
reduced the same influent over 90 percent.
Electrocoagulation consistently and
effectively reduces influent phosphate levels.
The process should be considered for application
to surface waters where eutrophication is a
problem.
The Electrocoagulation cell should also be
studied with respect to nitrate removal.
Variable ammonia reduction was
demonstrated under some test conditions.
Ammonia removal is of sufficient interest to
warrant further study of this application of the
cell.
g. BOD Reduction. Further testing
should be carried out to determine the
correlation between TOD and BOD in vessel
sewage in order to better predict watercraft
performance.
h. Phase III Description. Previous
testing and literature references had indicated
that the measurement of total oxygen demand
(TOD) could be used as a real time indicator of
influent and effluent BOD levels. A period was
reached in our test program where the
electrocoagulation process had little to no effect
in lowering TOD (and by inference BOD). A
Phase III test plan was initiated to characterize
in-house sanitary waste with respect to those
parameters which affect BOD and TOD. The
objective was to identify and eliminate the
reason for the apparent decrease in cell
efficiency and to optimize its performance for
treatment of concentrated sanitary waste.
Performance of the Phase III tests and
component development was completed March
6, 1970. The electrocoagulation cell was
operated with sanitary waste under a variety of
operating conditions; standard 35 amp/gpm, 70
amp/gpm, introduction of air into the cell while
processing and preaeration of the influent for
two different holding periods, Tables 12 and 13.
In addition, a series of runs was made using a
mixture of urea to simulate an influent
containing 100 percent soluble BOD. Urea was
selected since it is the major chemical
constituent of urine, which was assumed to be
contributing a large amount of soluble BOD to
the influent.
i. Phase III Results. Measurements of
total oxygen demand (TOD) and biochemical
oxygen demand (BOD) are tabulated for the
same samples in Tables 14 and 15. It can be seen
from examination of these tables that the TOD
may indicate an increase while the BOD
decreases. The effluent BOD is either below 50
ppm or with subsequent chlorination could be
lowered below 50 ppm.
The average BOD reduction was greatest
when the sewage was preaerated for sixteen
hours. A four hour aeration had no significant
effect on the percentage BOD reduction, while
adding air to the electrocoagulation cell had no
beneficial effect. It was speculated that ferrous
ions might be oxidized to ferric ions by the
101
-------
introduction of air and that a more effective
flocculation and clarification would be obtained.
j. Phase HI Conclusions. It remained to
determine the minimum quantity of flocculent
aid required to elevate pH and assure a clear
effluent and high density sludge. This was
accomplished by operating the
electrocoagulation cell and clarifier. Sodium
aluminate Al-46 and Separan NP10 with base are
the two candidate flocculent aids.
TABLE 12. PHASE III TEST RESULTS - G2 CELL INFLUENT AERATION
Parameter
Influent(1)
Pie-aeration sample
Effluent(2)
Effluent(2)
(pH 10)
4-hr aeration prior to treatment
Influent(1)
Effluent(2)
Effluent(2)
(pH 10)
UreaN
Ammonia N
TSS
FSS
TOD
BOD
pH
Turbidity
Residual Fe
Total Fe
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(JTU)
(ppm)
(ppm)
52
20
390
206
110
7.2
19
52
15
20
20
95
39
7.4
19
120
16
20
20
32
10.0
18
20
368
200
90
7.5
29
60
20
20
20
31
7.4
37
31
64
17
20
20
38
10.0
9
NOTES:
Influent = 50% sea water + 50% sanitary sewage and wastewater from RESD, Research and Engineering Center.
^ 'Decanted supernatant flocculated with 2 ppm NP10 and stirred at 80 rpm for 2 minutes, 10 rpm for 30 minutes, and 0 rpm for
30 minutes.
LIPFLOW CLARIFIER
a. Description. To make the
electrocoagulation process effective in a waste
treatment system, flocculation and settling must
occur rapidly. In laboratory tests this
clarification may be accomplished by jar-test
settling or centrifugation, both of which require
decanting the clarified liquor so as to complete
separation. Achieving the same degree of
clarification in a constant flow system, which
may be in a state of motion and where severe
limitations exist on detention time of
wastewater flow, dictates the need for planning
a significant development effort.
An evaluation of techniques and hardware
available for solids separation in a continuous
flow process resulted in the conclusion that an
independent development would be required. A
review of the hardware used for settling in
land-based applications revealed that a truck
mountable Upflow Clarifier could be redesigned
to operate while in motion. The typical motion
specifications commonly accepted are shown in
Figure 17.
Not unlike the open-topped experimental
electrocoagulation cells, the design of the
open-topped clarifier required extensive change
to make it suitable for use in a watercraft. The
clarifier was sized to provide a one hour
102
-------
TABLE 13. PHASE III TEST RESULTS - G2 CELL INFLUENT AERATION
Parameter
Pre -aeration sample
Influent* l)
Effluent'2'
(35 amp/gpm)
16 Mr aeration prior to treatment
Influent(1)
Effluent(2)
(35 amp/gpm)
Effluent(2)
(35 amp/gpm) pH 10
Urea N
Ammonia N
TSS
l-SS
TOD
BOD
pH
Turbidity
Residual Fe
Total Fe
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(JTU)
(ppm)
(ppm)
32
10
460
62
82
7.5
59
0
30
10
108
20
35
7.8
21
0
30
8
298
216
136
7.1
44
0
26
9
20
20
13
6.6
100
64
34
9
20
20
120
17
10.0
4
Influent = 50% sea water + 50% sanitary sewage and wastewater from RESD, Research and Engineering Center.
'"'Decanted supernatant flocculated with 2 ppm NP10 and stirred at 80 rpm for 2 minutes, 10 rpm for 30 minutes, and 0 rpm
for 30 minutes.
TABLE 14. PHASE III TEST RESULTS - G2 CELL CURRENT DENSITY EFFECTS
Parameter
Normal run
Influent'25
Effluent(3)
(35
amp/gpm)
Influent(2)
Cleaned cell
Effluent(3)
(35
amp/gpm)
Influent'2)
Effluent(3)
(70
amp/gpm)
Air Added to ECC during run'15
lnfluent(2)
Effluent(3)
(15
amp/gpm)
Effluent(3)
(70
amp/gpm)
UreaN
Ammonia N
TSS
FSS
TOD
BOD
PH
Turbidity
Residual
iron
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(JTU)
( ppm I
25
20
128
28
450
186
7.3
63
.65
25
20
20
20
218
60
7.1
10
1.2
25
24
20
420
206
7.6
70
20
20
20
278
63
8.3
23
23
20
20
390
174
7.6
62
12
20
20
526
63
8.0
20
46
23
322
38
88
7.5
48
40
22
<20
<20
58
7.5
24
40
22
<20
<20
60
7.6
28
(1)Air added at lOscfm.
'^Influent = 50% sea water + 50% sanitary sewage and wastewater from RESD, Research and Engineering Center.
'^Decanted supernatant flocculated with 2 ppm NP10 and stirred at 80 rpm for 2 minutes, 10 rpm for 30 minutes, and 0 rpm for
30 minutes.
103
-------
TABLE 15. PHASE III TEST RESULTS - G2 CELL UREA INFLUENT
Parameter
InHuent(1)
15 amp/gpm
Effluent(2)
Effluent(2)
(pH 10)
35 amp/gpm
Effluent(2)
Effluent(2)
(pH 10)
70 amp/gpm
Effluent(2)
Effluent* 2)
(pH 10)
UreaN
Ammonia N
TSS
FSS
TOD
BOD(3)
PH
Turbidity
Residual iron
Total Iron
(ppm) 100
(ppm) 7
(ppm) 20
(ppm) 20
(ppm) 240
(ppm)
7.2
(JTU) 20
(ppm)
(ppm)
90
17
20
20
195
6.4
43
38
100
15 14
20 20
20 20
190 250
10 6.8
14 24
119
46
12 9
20 20 20
20 20 20
250 260 235
10 8.0 10
7 32 6
264
'Influent = 50% sea water + 50% tap water and 76 grams urea.
Decanted supernatant stirred at 80 rpm for 2 minutes, 10 rpm for 30 minutes, and 0 rpm for 30 minutes.
No C>2 demand exerted by urea in the BOD determination.
HORIZONTAL
REFERENCE LINE
WATER LINE
/3= ROLL ANGLE = 30 MAX
PERIOD OF ROLL 10 SEC
(3= MAX ANGLE OF PERMANENT
LIST= 15-30ฐ
9 MAX ANGLE OF PERMANENT TRIM
1 -3 1/2ฐ
a PITCH ANGLE = 15ฐ MAX
PERIOD OF PITCH 6 SEC MAX
Figure 17. Motions Comprising Shipboard Environments
detention, a design objective which while
keeping the component volume down dictates
that a flocculent aid be used to speed
sedimentation by gravity.
After the decision was made to use an
upflow clarifier for solids separation, it was
necessary to investigate usage of a model
because of the expense of a full-sized unit.
Mathematical study (Reference 3) of the
correlations between a model and the full scale
component concluded the following:
104
-------
1- If the Vz-scale geometric model and
full scale component are operated with the
actual detention time, then the effluent from
the model is not representative because of a
shorter settlement height.
2. If the scaled model and full scale
component are operated with the actual
overflow rate, then the effluent from the model
is degraded since detention time would be less
for the model effluent.
Based on the undesirable compromises
indicated for modeling, a full size clarifier
fabrication was subcontracted. The analysis of
sedimentation in dynamic environments
(Reference 3) had also concluded that a
restrained body of liquid could be considered to
behave as a rigid mass. The existent model
clarifier made by Met Pro Water Treatment
Corporation with the changes made by
GE-RESD to eliminate sloshing is depicted in
Figure 18.
The upflow clarifier configuration which is
incorporated in the shipboard system evolved in
INFLUENT
EFFLUENT-
UPFLOWAREA2
UPFLOW AREA 1
DOWNCOMER
AGITATOR
A2
A1
V1 _
V2
11.47 ft2
0.59 ft2
.113 ft/mm
.058 ft/mi n
19.5
= 19.5
Figure 18. Upflow Clarifier Cutaway View
three stages of development. Each of the
hardware modifications was made to further
increase the total suspended solids content of
the withdrawn sludge. An objective established
by the incinerator capacity was a sludge
containing 2 percent total suspended solids
(TSS). For a system which treats 2500 gal/day
of wastewater with an average of 720 ppm TSS,
a 1 percent TSS sludge requires incineration of
approximately 200 gal of sludge, while a 2
percent sludge requires approximately 100 gal.
The additional percentage reduces the
incinerator load in half.
A sludge withdrawal schedule of four
withdrawals lasting three minutes at 2 gpm/hr of
elapsed operation will be initially programmed.
Indications that long term operation of the
clarifier makes achievement of a 2 percent TSS
sludge possible will permit adjustment of this
schedule in Phase II tests.
The development of the clarifier concluded
with a successful test on the motion simulation
platform.
b. Development Effort. An extensive
development effort was expended on the upflow
clarifier. This may be in part explained by the
need to develop an effective sedimentation tank
operating in the short time of one hour and also
assure similar performance while in motion. The
primary test objective was a continuing
improvement in the total suspended solids
content of the sludge. The work in sludge
concentration continues in the laboratory even
with shipment of the prototype.
In the early period of testing, difficulties
were encountered in getting sufficiently long
runs because of inadequate influent sewage.
Changes to the building sewage line made during
the test program eliminated the sewage shortage.
In the following discussions regarding the
hardware configuration tested, the performance
results will be examined and the rationale for
any changes developed. The three configurations
are distinguished as were the cells by group
callouts: Gl,G2andG3.
105
-------
The Gl clarifier configuration will be
described in some detail since it comprises the
heart of all three configurations. The internal
configuration is depicted in Figure 19 and the
external configuration in Figure 20. The
capacity of the unit is 300 gal which at a
wastewater flow of 5 gpm provides a detention
time of one hour.
The wastewater influent contents of floe
and flocculent aid enter near the center of the
clarifier into a volume containing a rotating
shaft and disks. This volume is referred to as a
downcomer and it is sized to provide
approximately 20 min of mixing. At the base of
the downcomer the rotational velocity of the
flow is reversed and the upflow begun in a
gradually increasing volume. Here the process of
Figure 19. Gl Upflow Clarifier Photograph
sedimentation builds up a sludge blanket.
Supernatant upflows over the weir level and is
then disinfected in the chlorination tank. The
sludge is withdrawn when the blanket level
interrupts the light source and photoelectric eye.
The G2 clarifier configuration shown in
Figure 20 adds to the basic configuration a
50-gal concentrator tank which is connected to
the clarifier. Sludge is transferred through the
connecting pipe at 0.5 gpm. Clarified liquid
from each tank in the ratio of 4.5 to 0.5 gpm
results. The photoelectric eye detection scheme
for sludge withdrawal was replaced by
sequenced withdrawals.
The G3 clarifier configuration shown in
Figure 21 evolved during system test. This
change altered the mode of operation of the
clarifier and concentrator as follows: sludge was
transferred by pump to the concentrator and the
concentrator effluent was recycled to the
downcomer.
c. Gl Clarifier Test Program. The test
program to evaluate the solids separation
capability of the Gl clarifier began with
influents of known solids composition. Initial
tests utilized the electrocoagulation cell effluent,
comprised of seawater and ferrous hydroxide, to
evaluate sedimentation characteristics.
Elemental tests to study sludge blanket
detection techniques and sludge withdrawal
rates were performed on this clarifier. An
objective for total suspended solids content of 2
percent in the withdrawn sludge was established
on the basis of incinerator capacity. The
proposed purchased incinerator had a stated
capacity of 100 gallons daily, which yields the
required total suspended solids content as
follows:
The average total suspended solids influent to the
clarifier is from Table 16, 720 ppm, and including
115 ppm of Fe(OH)2 is therefore .... 835 ppm TSS
allowable effluent level 50 ppm TSS
the daily wastewater flow is 2500 gal
and, the solids to be removed daily
2500 x (835-50) x 3.79 = 16.2 Ib
454x 103
106
-------
which results in a concentration requirement of:
16.2 IbTSSper 100 gal or
19,400 mg/1 ^ 2 percent
The performance of the Gl Clarifier is
tabulated in Table 17. The grab samples taken
during the sludge withdrawals at the times noted
had a total suspended solids content generally
less than 1 percent. The double entries under
run 2 indicates different sample times.
Several attempts to utilize a light source
and photoelectric eye to sense sludge blanket
height failed. Because of discoloration to the
sight windows by sludge, the optical system
proved unreliable.
Sludge withdrawal was improved by
operating the agitator continuously for
breakthrough of supernatant liquor was found if
the pump-out occurred without rotation of the
blanket.
The initial tests of the clarifier indicated
that with addition of a flocculent aid,
separation, compaction, and clarification were
occurring in the detention time of one hour. The
clarified effluent sampled showed excellent total
suspended solids reduction in influent levels.
However, the total suspended solids content of
the sludge averaged less than 1 percent or
10,000 ppm.
Based on these test results showing that
insufficient compaction of the sludge blanket
occurs in sixty minutes, the clarifier was
returned for a major alteration to add a 50-gal
concentrator tank. By transferring sludge from
the clarifier at 0.5 gpm, an additional 100 min
of compaction would be provided.
d. G2 Clarifier Test Program. This
configuration clarifier which added the
concentrator was extensively tested with the full
range of wastewater influents. Within this
configuration several operating modes were
52-11/16"
FLOC AID PORT
50
D
INF
EFF
CONCENTRATOR
23"D
EFF
TUBE SETTLER
MODULE
26"
SLUDGE WITHDRAWAL
PUMP
Figure 20. G2 Upflow Clarifier with Concentrator, Elevation View
107
-------
CLARIFIER
FLOC AID PORT
INF.
TUBE SETTLER
MODULE
SLUDGE RECYCLE
PUMP
SLUDGE WITHDRAWAL
PUMP
Figure 21. G3 Upflow Clarifier Modified After System Test
TABLE 16. RESULTS OF THE WASTEWATER SURVEY DREDGE GERIG
Flow
(gpm)
Biochem
ฐ?
demand
(ppm)
Total O2
demand
(ppm)
Conductivity^ '
Ortho
phosphate
(ppm)
Total
phosphate
(ppm)
Total
suspended
solids
(ppm)
Total
volatile
solids
(ppm)
Detergent
(ppm)
Ca++
(ppm)
Mg++
(ppm)
PH
High
Low
Avg
High
Low
Avg
High
Low
Avg
4.8
0.8
2.2
4.0
0.5
2.0
2.6
1.7
2.2
879
402
665
836
185
554
790
590
713
2308
612
1229
825
175
483
1275
700
950
38
16
28
28
9
16
23
9
18
35
18
25
29
12
21
25
13
21
123
32
64
126
12
50
42
32
37
1033
556
720
1390
121
509
654
280
464
863
213
532
1170
89
443
532
240
382
210
6
64
906
5
174
102
25
63
124
33
88
198
75
125
151
90
116
269
55
163
400
112
256
272
147
214
8.4
6.7
8.0
8.5
6.9
7.9
7.7
7.1
7.5
'Conductivity (p.mhos/cm x 10" )
investigated: These include reduction in the
speed of rotation of the agitator, pump rate and
duration of withdrawal of sludge, and the effect
on sludge of intermittent and continuous
transfer. Some effort was devoted to evaluation
of an automatic decant of supernatant from the
concentrator prior to sludge withdrawal.
Only the two conditions pertaining to
sludge transfer will be further discussed.
Intermittent sludge transfer is defined as transfer
at 0.5 gpm whenever the system is operating.
Continuous transfer is defined as 0.5 gpm flow,
which is continuously recycled into the
downcomer even when the system is not
108
-------
operating. If sludge transfer is continuous, then
the clarifier-sludge requirements is derived from
Figure 22.
Let:
c
w
t
Then:
- total suspended solids concentration.ppm
= flow, gpm
= time, min
(C1-C2)xW1xta-C3W3tc
ta = 500 min of system operation
tb = 1392 min excluding sludge withdrawal
time
tc = 1440 min
tjj = 48 min of sludge withdrawal
Wj = 5 gpm
W3 - 0.5 gpm
W4 = 0.5 gpm
= 2.0 gpm
This level is achievable in the clarifier as
demonstrated in test. A similar computation for
a concentrator operating on intermittent sludge
transfer yields a requirement for 4 = 10,000
ppm. Without a major change such as in
detention time or volume, an intermittent
transfer is not practical.
The performance of the G2 clarifier, during
runs 2 through 10, is tabulated in Table 18 with
definition of the test conditions established.
Based on further tests of the optical sensing
system for sludge blanket detection, the positive
sensing mode was replaced by preprogramming
sludge withdrawals based on system operating
time.
The most favorable sludge total suspended
solids content was achieved by the shorter
duration, higher pump rate withdrawal as
demonstrated in run 10. The effluent TSS
content was generally below 20 ppm.
TABLE 17. G1 CLARIFIER TEST RESULTS, RUNS 1 AND 2
Also, the minimum clarifier sludge concentration follows
(835 -50)x5 x 500 - 50 x 0.5 x 1440
C4 = 0.5 x 1392 + (0.5 + 2.0) 48 Clarifier
flow rate
C4 = 2361 ppm
Flocculent
aid rate
(1)1 ' ) ( duration
^ Agitator
(9) speed
Influent
I J Sample
\ / ^\ / timeS
\ \/^W <5> n r
X f ^ :_m j.
(1) Clarifier Influent (4) Clarifier Sludge Transfer Clarifier
(2) Clarifier Effluent (5) Concentrator Sludge effluent
(3) Concentrator Recycle Effluent
Clarifier
sludge TSS
Figure ?? riarifier-Sludee Derivation Fieure.
Test Run
1
5 gpm
3 ppm
NP10
80 min
115 rpm
Seawater
78 min
115 ppm
<20ppm
3038 ppm
2
5 gpm
4 ppm
NP10
140 min
115 rpm
Seawater
80 min ! 100 min
I
i
|
1 1 j ppm i
i
i
i
i
9159 ppm 1 9680 ppm
1
109
-------
TABLE 18. G2CLARIFIER TEST RESULTS, RUNS 3 THROUGH 10
Run
darifier
flowrate (gpm)
Flocculent
aid late (ppm)
Test dur-
ation (min)
Agitator
speed (rpm)
Influent
Sample
times (min)
Clarifier in-
fluent
TSS (ppm)
Clarifier
effluent
TSS (ppm)
Clarifier
sludge
TSS (ppm)
Concentrator
sludge
TSS (ppm)
Concentrator
flowiate (gpm)
3
5
2.5
NP10
260
115
Seawater
60 760
238
7702 13300
0.25
4
S
2.5
NP10
90
54
Seawater + sewage
10 35 70 90
1260 946 648 782
<10 54 <10 <100
642 1754 2020 2660
2400 9140 13260 13624
0.33
5
5
.05 % sodium
aluminate
195
54
Seawater +
sewage
75 135 195
788
<20
2990 3060
3950 4290 4560
0.5
6
5
2.5
A23 + NaOH
140
54
Seawater +
sewage
140
358
<20
6996
Composite
0.5
7
5
0.1%
sodium aluminate
165
54
Seawater + sewage
15 135 155 165
562
<20
1708
ljป972 370 122;
5/8 gpm'
0.5
8
5
.05 %
sodium aluminate
140
54
Seawater + sewage
60 120 130 140
304
<20
1288
v 4H4 240 88j
5/8 gpm*
0.5
9
5
.05 %
sodium aluminate
165
54
Seawater + sewage
65 140 155 165
380
2198
vi0052 3816 258,
^5/8 gpm*
0.5
10
5
2.5
NP10
117
54
Seawater + sewage
88 92 95 107 117 140 144 145.5 147
<20 <20
2184 2196 1776 1936 6552 2256 1928
J4932 5008 2852 2436 y v.8268 100748730,1
^^ 0.75 gpm* ~^ 2 gpm*
0.75
NOTE: *These samples were obtained during Decanted Decanted Decanted Decanted
continuous sludge withdrawal. Cone. Cone. Cone. Cone.
-------
TABLE 19. G3CLARIFIER TEST RESULTS, RUNS 11 THROUGH 16
Run
daiifier
flowrate (gpm)
Flocculent
aid rate (ppm)
Test
duration (min)
Agitator
speed (rpm)
Sample
bme (mm)
Clarifer
influent
TSS (ppm)
Oarifer
influent
BOD (ppm)
Clarifer
effluent
TSS (ppm)
Clarifer
effluent
BOD (ppm)
Concentrator
sludge
TSS (ppm)
Clarifer
influent
Turb (JTU)
Clarifer
effluent
Turb (JTU)
11
5
.05 %
sodium aluminate
120
54
60 90 120
836 680
26 <20
12492 9348 11868
12
5
.05 %
sodium
aluminate
120
54
60 120
828 552
396
50 34
99
13
5
0.1 %
sodium aluminate
270
120
60 120 180 240 270
1000 824 716 400 484
408 390
34 22 40
145 113
12470 11870
90 130 100 90
24 16 18 24
14
5
0-1%
sodium
aluminate
180
150
60 180
872 672
68 58
26358
125 125
28 28
15
5
0.1%
sodium aluminate
216
150
60 174 216
856 436
108 58
20594
130 70
30 17
16
5
0.1 %
sodium
aluminate
132
150
60 132
752 356
52 28
19987
110 115
30 24
-------
The flocculent aids established as promising
in jar tests NPIO + NaOH and sodium
aluminate both aided suitable sludge blanket
formation within the hour detention time.
The decant technique tried in runs 6 to 9
did not improve the solids content of the sludge
sufficiently to warrant the complexity of an
additional electrically controlled valve.
In conclusion the clarifier configuration of
run 10 was considered the best performer of the
test sequence. Consequently, it was incorporated
for the start of system test. The sludge
withdrawal rate was established at 2 gpm, and
the recycle and transfer was established at 0.75
gpm.
The flocculent aid selected was NPIO with
added base, NaOH.
e. G3 Clarifier Test Program. The
changes incorporated to make the G3
configuration were not extensive. However, they
are the result of insights gained during longer
term tests with the increased sanitary sewage
source.
Evolvements during test are best
understood by reference to Figure 21 which
schematically indicates the G3 configuration.
Relocation of the sludge withdrawal port in the
clarifier transfers higher density sludge from the
blanket to the upper third of the concentrator.
The result appears to be a higher concentration
in the sludge because of a higher initial
concentration. A corollary change was the
increase of the transfer rate to 4 gal/min, the net
result being greater solids content within the
concentrator.
The performance of the G3 clarifier is
tabulated in Table 19. The flocculent aid
selected for use on the ship was sodium
aluminate because of the superior turbidity
reduction which results. Clarifier effluent
continued to yield effluents with a total
suspended content of less than 20 ppm. The
biochemical oxygen demand was reduced by 75
percent on the average. The reduction to below
50 ppm can be achieved by final chlorination of
the effluent. Sufficient data exists to assure that
the effluent BOD can be reduced to 50 ppm
from the unchlorinated effluent levels.
In conclusion the flocculent aid rate and
chlorination rate remain to be determined in the
initial trial runs on the watercraft utilizing vessel
waste.
f. G3 Clarifier Mot on Simulation
Test. This test subjected the G3 configuration
clarifier to a motion test on the specially
designed apparatus depicted in Figure 23. The
test performed at a rate of ฑ 20 degrees in 10 sec
demonstrated the nonsloshing design features of
the clarifier.
AT +20 DEC
Figure 23. Motion Simulation On G3 Clarifier
112
-------
REFERENCES
1. Program Plan - Shipboard Water Pollution Control
Project. General Electric Company. RESD Document
9324-596, Revision C. February 9, 1970.
2. Results of Sewage Characterization Study Dredge Gerig.
General Electric Company. RESD Document
9324ANY0743. September 30, 1969.
3. Sedimentation Study Under Dynamic Environments -
Model Dynamic Considerations. General Electric
Company. RESD Document 9333ANY403. September
30, 1969.
4. Laboratory Methods Manual. Hudson Champlain Project.
U.S. Dept of the Interior. FWPCA. December, 1966.
ACKNOWLEDGEMENT
The authors would like to acknowledge
the technical contributions of Mr. G.L. Weinberg
in the area of electrical design and of Mr. B.C.
Darrah for his many contributions to the system
mechanical design, fabrication and test cycle.
113
-------
APPENDIX B
SUMMARY OF GERIG SWTS TEST DATA
Location/Da
tes Sample Designation
Time
ppm
Residual
pH Chlorine
BOD5-ppm
Total
Suspended
Solids Coliform
PPm MPN col./lOOml
"AMPA, FLORIDA
10-17-70
10-28-70
lO-29-70
PASCAGOULA
Mean Data
1-8-71
]-9-71
2-10-71
1-11-71
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Effluent
Svstem Effluent
System Effluent
System Influent
System Influent
System Influent
System Jnfluent
System Effluent
System Effluent
System Effluent
System Effluent
, MISSISSIPPI
System Influent
System Effluent
System Influent
System Effluent
System Influent
System Effluent
System Influent
Svstem Effluent
1145
1400
0800
0900
1115
-
0900
1115
0700
1000
-
-
0700
1000
-
-
_
-
_
-
_
-
-
-
9.4
6.9
7.6
9.2
7.6
9.8
9.7
9.6
7.6
7.9
8.1
7.6
9.6
9.5
9.5
9.5
_ _
-
_ ป.
-
_ _
-
-
-
65
90
140
150
720
55
70
155
110
150
145
270
50
70
60
80
140
15
190
20
270
75
150
40
40
5C
880
100
940
80
25
25
950
940
320
-
20
80
70
70
420
20
150
20
430
i
1340
10
-------
Location/Da teB
BRUNSWICK, GEORGIA
3-11-71
3-13-71
3-14-71
3-15-71
3-16-71
Sample Designation
System Influent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
Time
-
*ป
-
-
-
-
-
-
-
0850
1030
1230
1430
0850
1030
1230
1430
0900
1100
1225
0900
1100
1225
0700
1400
ppm
Residual
pH Chlorine
_
* ซ
-
-
-
-
-
-
-
5.7
6.1
7.5
8.2
8.3 ^ 0.1
8.4 -60.1
8.4 ^0.1
8.4 <0.1
7.8
6.8
6.4
8.6 <0.1
8.6 <0.1
8.6 <0.1
7.2
6.9
BOD5-ppm
Total
575
220
1530
660
400
1400
210
470
300
280
530
580
130
270
190
170
190
190
1980
1350
762
180
240
200
360
900
Suspended
Solids
ppm
690
54
1450
290
160
630
17
50
30
95
520
780
210
470
60
60
80
80
800
640
410
15
20
25
720
650
Col i form
MPN col./ 100ml
-
-
-
-
-
-
-
-
>1 x 106
>\ x 106
>1 x 106
>1 x 106
>\ x 103
25
1
>1 x 103
>1 x 106
>1 x 106
>1 x 106
f\
>1 x 103
>1 x 103
>1 x 103
-
-------
Location/Dates
BRUNSWICK, GEORGIA
3-17-71
3-19-71
3-20-71
3-21-71
Sample Designation
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
Backage Water
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
Time
0920
1130
1345
1445
0920
1130
1345
1445
-
1255
1400
1445
1155
1255
1400
1445
0800
0945
1230
1430
0715
0945
1230
1420
0725
0930
1130
1330
PH
6.5
7.6
8.3
7.7
7.7
8.2
7.2
7.1
7.8
6.5
7.0
7.7
8.4
8.3
7.5
7.5
7.3
8.6
7.2
6.7
7.3
8.4
8.4
8.4
6.8
7.2
8.8
7.2
ppm
Residual
Chlorine
.
-
-
-
40
15
15
20
-
-
-
17
18
36
44
_
-
-
42
225
20
13
11
_
-
-
-
BOD5-ppm
Total
250
400
440
190
160
195
260
270
2
450
500
420
350
320
450
410
930
940
860
490
240
250
310
290
650
530
610
1130
Suspended
Solids Coliform
PPm MPN col./lOOml
520
410
250
360
90 < 1.0
60 ^-1.0
100 <1.0
65 ,<1.0
1.7 x 104
300
320
460
65 ^.1.0
60 <1.0
70 <1.0
70 -ฃ1.0
580
910
350
370
70 < 1.0
60 ">! x 103
50 Xl.O
60 ฃl.O
400
710
630
630
-------
oo
Location/ Date
3-21-71
3-22-71
3-23-71
3-24-71
Sample Designation
System Effluent
System Effluent
System Effluent-
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
Time
0725
0930
1130
1330
0725
0935
1210
1430
0725
0940
1210
1430
0845
1100
1230
1415
0850
1100
1230
1500
0930
1115
1300
1430
0930
1115
1300
1430
PH
9.0
8.9
8.7
8.5
7.3
9.5
8.0
7.8
8.9
8.9
8.8
8.4
7.0
8-7
7.6
8.1
7.7
7.7
8.4
8.5
6.2
5.2
7.3
8.8
7.8
9.1
8.9
8.8
ppm
Residual
Chlorine
15
27
21
11
-
-
-
11
32
33
14
_
-
-
-
55
69
138
127
-
-
-
84
80
61
49
Suspended
BOD5-ppm
Total
145
190
230
170
460
-
550
670
285
225
300
320
1400
330
620
320
180
245
225
300
Depleted
430
660
380
205
190
245
210
Solids
ppm
40
50
45
50
370
1510
210
190
40
30
50
60
720
410
420
430
50
80
60
170
1600
360
400
480
350
55
40
50
Coliform
MPN col./ 100ml
^ 1.0
<ฃ 1.0
-------
Location/ Date
3-25-71
3-26-71
3-27-71
Sample Designation
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
Background Water
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
Background-Buoy
Background-Dock
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
Background-Buoy
Time
1045
1230
1445
1045
1230
1315
1500
-
0845
1040
1230
1415
0845
1030
1230
1500
-
-
0830
1030
1300
1430
0830
1030
1300
1430
-
PH
7.2
7.6
7.4
8.3
8.7
8.9
8.8
7.8
7.1
7.2
7.3
8.5
8.7
8.6
8.6
8.6
6.9
7.1
7.0
8.3
7.0
7.1
8.7
8.7
8.3
8.0
7.6
ppm
Residual
Chlorine
.
-
-
27
-
50
27
-
.
-
-
-
57
49
47
36
-
-
mm
-
-
-
44
11
10
14
-
Suspended
BOD5-ppm
Total
220
100
130
180
125
110
95
1
370
820
610
210
3
140
290
180
-
1
340
730
310
650
125
280
385
435
1
Solids
ppm
500
180
280
55
46
140
36
-
620
810
420
390
60
45
35
105
40
40
470
650
220
500
90
55
20
30
55
Coliform
MPN col./lOOml
.
-
-
>1 x
1 x
2
-
103
,
104
103
-------
tc
o
Location/ Date
3-28-71
3-29-71
3-30-71
3-31-71
Sample Designation
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
Time
0830
1105
1320
1430
0830
1115
1345
1430
0850
1115
1430
1500
0850
1125
1430
1500
0830
0930
1315
1435
0900
0900
0900
0900
0830
1040
1255
1130
1300
1400
pH
7.0
7.7
7.4
7.4
8.5
8.5
8.6
8.6
7.0
7.5
8.0
8.0
8.9
8.9
8.9
8.8
7.1
7.0
7.9
7.3
8.5
8.6
7.9
8.9
7.8
8.4
7.9
8.4
8.6
8.7
Ppm
Residual
Chlorine
w
-
-
-
31
33
48
45
.
-
-
-
77
106
70
67
w
-
-
-
35
70
320
52
_
-
-
32
27
22
Suspended
BOD5-ppm
Total
140
590
1370
330
205
175
195
90
230
710
350
250
165
180
180
165
Depleted
Depleted
Depleted
290
88
85
40
84
440
230
410
200
180
150
Solids
ppm
420
140
860
240
280
90
50
10
40
230
200
120
15
15
30
15
1020
820
580
90
10
15
20
20
310
320
230
20
15
90
Col i form
MPN col./ 100ml
^
-
-
-
-------
(S3
Location/Date
4-1-71
4-2-71
4-3-71
4-4-71
Sample Designation
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
Time
0910
1100
1255
1405
0950
1110
1255
1440
0845
1115
1255
1415
1000
1115
1255
1415
_
-
-
-
-
-
-
-
0810
1050
1300
1410
1015
1120
1325
1415
P.H
7.2
8.5
7.3
8.1
8.2
8.6
7.6
7.6
6.4
7.5
8.4
8.0
8.7
8.6
8.6
8.5
7.5
8.2
7.1
7.8
8.8
8.8
8.7
8.6
7.1
7.2
6.9
7.6
7.4
7.5
7.6
7.8
ppm
Residual
Chlorine
.
-
-
-
49
50
49
38
-
-
-
25
16
16
14
_
-
-
-
46
58
60
66
_
-
-
-
22
19
22
29
Suspended
BOD5-ppm
Total
980
760
1250
670
195
250
320
495
Depleted
230
1370
1420
130
140
165
185
280
590
1240
230
155
180
330
380
420
180
1400
190
240
245
235
285
Solids
ppm
890
510
640
360
50
45
40
50
1020
190
750
1500
35
10
20
30
180
600
590
180
15
20
25
80
400
230
560
65
75
60
60
110
Col i form
MPN col./100mJ
-
-
-
ซC 1.0
ฃ1.0
<1.0
ฃ1.0
-
-
-
ฃ 1.0
ฃ 1.0
ฃ-1.0
ฃ1.0
_
-
-
-
-------
bo
to
Location/Date
4-5-71
4-6-71
4-7-71
Sample Designation
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
Time
0830
1030
1240
1400
0915
1030
1240
1410
0840
1015
1135
1340
0840
1020
1135
1340
-
-
-
-
-
-
-
. ...PH .
7.2
6.8
7.1
7.1
7.6
7.7
8.2
8.1
6.5
3.8
6.8
8.9
7.6
7.9
8.3
8.4
7.3
8.9
7.0
7.2
8.1
8.0
8.1
8.2
ppm
Residual
Chlorine
^
-
-
-
26
28
41
45
-
-
-
24
39
117
170
-
-
-
60
55
30
30
Suspended
BOD5-ppm
Total
600
650
1320
290
235
205
160
275
680
230
320
780
195
290
255
245
270
450
Depleted
470
195
190
210
255
Solids
ppm
480
580
750
280
100
50
50
75
630
250
190
620
40
60
50
135
230
780
940
295
60
60
65
60
Coliform
MPN col./ 100ml
-
-
-
< 1.0
< 1.0
<1.0
il.O
^
-
-
-
7
6
^-1.0
< 1.0
-
-
-
< 1.0
< 1.0
39
900
-------
txs
CO
Location/ Date
4-8-71
4-9-71
Sample Designation
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
Time pH
7.9
7.0
7.2
7.4
8.8
8.8
8.9
9.0
6.6
9.4
7.3
7.3
9.1
9.2
9.3
9.3
ppm
Res idual
Chlorine
-
-
-
0.5
0.5
58
51
-
-
-
31
16
146
136
Suspended
BOD5-ppm Solids Coliform
Total PPm MPN col./lOOmi
360
620
290
770
195
220
185
160
>
_
_
-
_
-
-
-
-------
tso
Location/Dates
ppm
Residual
Sample Designation Time pH Chlorine
BOD5-ppm
TC n
Dissolved
Suspended
Solids Col i form
PPm MPN col./lOOml
BOCA GRANDE, FLORIDA
4-16-71
4-17-71
Kev^ Influent
"A"
"B"
C
D
"E"
System Influent 0915
Sample "A" 0935
Sample "A" 1245
Sample "B" 0945
Sample "C" 0930
Sample "C" 1150
Sample "D" 0945
Sample "E" 0950
Sample "E" 1430
System Influent 0825
System Influent 1000
System Influent 1110
System Influent 1235
System Influent 1345
Sample "A" 0905
Sample "A" 1345
Sample "B" 1345
Sample "C" 0830
Sample "C" 1150
Sample "C" 1340
Sample "D" -
Sample "E" -
Sample "E" 1145
Sample "E" 1350
- Influent to system
975
59
48
-
59
%
-
78
44
585
270
350
1020
275
92
50
46
72
52
72
-
430
74
172
60
48
45
-
-
44
-
70
-
190
85
190
155
60
44
46
42
-
50
65
-
-
-
-
1880
900
_
1930
-
580
19000
470
630
430
1990
2870
1660
3660
710
1670
3360
-
750
-
15400
605
470
470
= Recycle/Effluent from sludge concentrator
= Influent to sludge concentrator
= Effluent from clarifier
= Sludge Concentrator Effluent
= System Effluenf
-------
ppm
Residual BOD5-ppm
Location/Dates Sample Designation
4-19-71 System Influent
System Influent
System Influent
System Influent
System Influent
Sample "A"
Sample "A"
Sample "A"
Sample "B"
Sample "B"
Sample "C"
Sample "C"
Sample "D"
Sample "E"
Sample "E"
4-20-71 System Influent
System Influent
Sample "A"
Sample "A"
Sample "B"
Sample "B"
Sample "C"
Sample "D"
Sample "E"
Sample "E"
4-21-71 System Influent
System Influent
Sample "D"
Sample "D"
Sample "E"
System Effluent
Time pH
1100
1400
1440
1645
1800
1415
1800
2130
1415
1800
1430
1800
1800
1800
2130
0745
0745
0930
1445
0930
1445
1445
1000
0825
1445
1210
1400
1210
1400
1220
1400
Chlorine ,tal
336
264
762
406
1668
42
43
46
45
40
39
43
-
41
43
271
340
43
47
38
54
51
-
92
45
666
214
430
340
44
41
Dissolved
319
184
546
76
606
37
42
35
40
39
-
41
-
39
-
106
256'
26
46
24
53
40
-
-
-
120
84
52
73
35
37
Suspended
Solids Coliform
PPm MPN col./lOQml
705
545
4050
150
100
57
72
99
680
87
17
49
5360
160
72
900
940
250
50
45
1900
77
10100
30
100
570
500
17670
26020
180
180
See Key page B-10
-------
to
Oi
Location/Dates
4-22-71
SOUTHPORT, NORTH
4-29-71
4-30-71
5-1-71
Sample Designation
System Influent
System Influent
Sample "A"
Sample "B"
Sample "C"
Sample "D"
Sample "D"
System Effluent
System Effluent
CAROLINA
System Influent
System Influent
Sample "C"
Sample "C"
Sample "E"
Sample "E"
Background Water
System Influent
System Influent
System Influent
Sample "C"
Sample "C"
Sample "C"
Sample "E"
Sample "E"
Sample "E"
System Influent
System Influent
System Influent
Sample "E"
System Effluent
System Effluent
Time
1000
1330
1335
1335
1330
1000
1335
1000
1330
1030
1330
1050
1400
1100
1330
-
1600
1915
2200
1615
1940
2135
1620
2200
0645
1030
1622
1910
1045
1630
1920
PH
w
-
ซ
-
-
-
-
-
-
9.2
8.1
8.7
8.7
8.9
8.9
8.3
9.2
8.6
8.1
8.6
8.6
8.4
9.0
8.7
9.2
7.2
7.9
7.0
8.9
9.0
8.7
ppm
Residual
Chlorine
-
-
-
-
-
-
-
-
-
11
35
34
43
-
M
-
-
13
13
11
16
11
25
-
-
10
9
7
BOD5-ppm
cal
706
956
34
32
34
40
-
29
35
880
1150
130
130
130
130
0.3
610
250
450
130
130
130
130
130
110
890
260
620
110
300
220
Dissolved
373
585
33
31
-
31
31
27
34
490
820
-
-
-
-
-
300
200
170
-
-
120
-
-
-
390
100
220
-
-
-
Suspended
Solids Coliform
ppm MPN col./100m]
1210
3640
1030
2050
435
3580
16210
74
280
870
1600
33
15
60 <1.0
50 <.1.0
40 1700
190
230
200
44
50
84
52
13
34
330
200
430
14
38
20
See Key page B-10
-------
to
Location/Dates
5-2-71
5-7-71
5-10-71
5-11-71
5-12-71
5-16-71
Sample Designation
System Influent
System Effluent
System Influent
System Influent
System Effluent
System Effluent
Standard
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Intiuent
System Influent
System Influent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
Time
1300
1430
0600
1200
0600
1200
-
0630
1300
1800
2200
0630
1300
1800
2200
0600
0930
0600
0930
1100
1745
2000
2000
2200
1015
1615
2030
1420
1830
2220
PH
7.9
9.G
7.8
8.2
8.7
9.0
-
8.2
8.5
5.6
7.3
9.1
9.1
9.0
8.9
8.1
6.8
8.8
9.2
9.1
5.5
7.9
9.1
9.0
8.5
7.6
9.0
9.0
8.7
8.8
ppm
Res idual
Chlorine
^
47
-
12
21
-
-
-
-
9
8
6
8
-
7
29
-
-
20
20
=
-
-
30
20
22
BOD5-ppm
Total
450
215
500
780
137
320
200
380
820
1500
260
162
190
138
480
370
1750
450
425
2000
1600
640
210
225
670
160
190
245
135
132
Dissolved
220
-
150
350
-
-
-
185
155
800
100
-
-
-
-
170
350
-
-
800
920
260
-
-
_
-
-
-
-
-
Suspended
Solids Coliform
PPm MPN coL/IOOml
250
150
M M
-
~
~
-
270
580
1300
220
60
40
65
90
900
800
44
50
1000
930
330
70
30
470
230
280
18
74
50
-------
00
Location/ Dates
5-17-71
5-24-71
5-25-71
5-26-71
6-20-71
6-21-71
Sample Designation
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Effluent
System Effluent
Standard
System Influent
System Influent
System Effluent
System Effluent
System Influent
System Effluent
System Effluent
System Effluent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
Time
0630
1020
1730
2100
0630
1330
1950
2200
0820
1200
1015
1400
0030
0800
1330
1000
1330
-
0800
1200
1000
1400
1145
0850
1145
1405
1225
0830
1025
1235
1430
_BH
6.8
7.8
5.3
7.5
8.9
9.3
9.5
9.6
8.7
8.6
9.0
9.1
8.3
7.0
9.5
9.2
9.2
-
8.3
7.3
9.0
9.1
7.4
9.0
9.2
9.9
6.7
8.8
8.8
8.9
9.0
ppm
Residual
Chlorine
m
-
-
31
21
16
8
-
42
37
-
-
34
15
-
_
-
68
42
_
Kmn04
+ OCL
Exp.
_
Kmn04
+
OCL
Exp.
Suspended
BOD5-ppm Solids Coliform
Ivjtal
760
460
1100
680
154
330
315
270
540
120
185
230
540
1300
520
310
425
240
860
600
340
340
300
140
140
160
220
240
690
690
680
Dissolved PPm MPN col./lOOml
570
355 204
475 510
290
33
64
63
75
240 680
40 360
100
80
w
-
- -
_
_
_
v
-
-
-
.
-
_
-
ป M
-
-
_
-
-------
to
CD
Location/Dates
6-22-71
6-25-71
6-26-71
7-9-71
7-10-71
7-14-71
Sample Designation
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Effluent
System Effluent
System Influent
EC Cell Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Effluent
System Influent
System Influent
System Influent
System Effluent
System Effluent
System Effluent
System Influent
Carbon Column Inf.
Effluent 2nd Col.
System Effluent
Time
1220
0800
1000
1220
1400
1330
0800
1345
0845
0848
0800
1000
1400
0830
1030
1225
1400
0800
1030
1225
1400
0800
1000
1200
0800
1000
1200
1100
1310
1315
1415
pH
9.2
8.8
9.0
9.0
8.9
8.6
9.4
9.6
7.1
7.1
8.9
8.9
8.9
7.8
8.2
7.0
7.5
8.7
8.8
9.5
9.1
9.4
8.2
8.7
8.9
9.5
9.3
8.6
9.3
7.6
7.6
ppm
Residual
Chlorine
fm
KmnO^
+
OCL
Exp.
14
51
-
15
20
17
-
-
-
-
-
102
36
_
-
-
15
75
46
_
28
5
5
Suspended
BOD5-ppm Solids Coliform
Total Dissolved PPm MPN col /100ml
290 -
170 - -
165 -
170 - -
220 - - -
880 -
140 - -
210 -
400 -
420 -
155 - -
150 - -
160 - -
1460 660
215
430 220
820
260
240
220
215
235
770 340
300
320
285
275
420 - 1510
230 - 34
46 14 -
47 20
-------
co
o
Location/ Dates
7-15-71
7-16-71
7-17-71
7-18-71
Sample Designation
System Influent
Carbon Column Inf,
Effluent 2nd Col.
Effluent-System
Carbon Column Inf.
Effluent 2nd Col.
System Effluent
System Influent
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Col.
Effluent 2nd Col.
System Effluent
System Effluent
System Influent
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Effluent
System Influent
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Effluent
Time
0830
0900
0900
0900
1300
1300
1300
0810
0830
1330
0830
1330
0830
1330
0810
0830
1330
0850
1330
0810
1315
0900
0900
1300
0900
1300
0900
1300
pH
7.9
9.2
8.4
7.8
9.3
8.6
8.1
7.8
9.1
8.9
7.3
7.4
7.9
7.7
8.2
9.2
9.4
7.5
7.5
7.5
7.5
8.9
9.2
9.3
7.5
7.5
7.5
7.5
Ppm
Residual
Chlorine
20
-
-
25
10
-
25
17
-
-
-
-
26
56
-
-
-
-
25
35
-
-
-
-
Suspended
BOD5-ppm Solids Coliform
Tot .1
500
160
80
62
280
82
60
380
150
150
135
100
155
95
220
120
130
90
64
104
76
360
120
205
58
94
70
74
Dissolved PPm MPN col./lOOml
1570
27
11
2
43
21
20
1175
41
26
204
62
12
16
500
26
20
55
23
5
6
160 1020
38
54
35
70
17
24
-------
co
Location/Dates
7-19-71
7-20-71
7-21-71
7-23-71
Sample Designation
System Influent
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Influent
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Effluent
System Effluent
System Influent
Carbon Column Inf.
Effluent 2nd Column
System Effluent
System Influent
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Effluent
Time
1300
1100
1400
1100
1400
1400
1015
0800
1400
0800
1400
0800
0915
1400
0800
0800
0840
0840
1200
0810
1330
0810
1330
1330
1430
pH
8.7
8.9
9.3
7.6
7.8
7.7
8.8
9.0
9.2
7.8
8.0
7.8
8.6
8.0
8.5
9.6
7.7
7.7
7.9
9.1
9.0
7.7
8.1
8.0
7.9
ppm
Residual
Chlorine
22
44
-
-
-
^
8
9
-
-
-
-
-
_
37
-
-
30
25
-
-
-
-
Suspended
BOD5-ppm Solids Coliform
Total
400
125
170
55
58
46
600
130
210
56
105
58
72
76
240
105
60
60
58-
165
200
118
90
100
118
Dissolved PPm MPN col./lOOml
120 580
50
66
15
50
28
160 1770
45
45
47
100
25
30
60
140 420
24
125
30
330 580
51
36
153
102
58
144
-------
co
to
Location/Dates
7-26-71
7-27-71
7-28-71
7-29-71
Sample Designation
system Influent
Carbon Column Inf.
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Effluent
System Effluent
System Influent
Carbon Column Inf.
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Effluent
System Effluent
System Influent
System Influent
Carbon Column Inf.
System Effluent
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
System Effluent
Time
0815
0820
1300
1500
0820
1300
1500
0820
1300
1500
1100
0830
1230
1445
0830
1230
1445
0830
1230
1445
_
_
0830
1345
1345
0830
1345
0830
PH
4.4
8.6
8.8
8.8
7.8
7.9
7.9
7.4
7.4
-
8.8
8.6
9.2
9.2
7.9
8.0
8.3
7.3
7.4
7.4
8.0
7.8
8.5
9.0
7.6
7.5
7.9
8.5
ppm
Residual
Chlorine
.
8
14
13
-
-
-
-
-
-
8
38
40
-
-
..
-
ป
-
^,
ซ
8
75
-
-
-
-
Suspended
BOD5-ppm Solids Coliform
Total
340
122
115
141
62
82
82
42
49
89
720
118
215
224
68
52
88
32
32
68
1400
340
99
66
54
61
59
66
Dissolved PPm MPN col./lOOml
170 460
14
40
20
190
90
90
40
95
60
440 640
20
76
48
90
50
42
45
18
44
90 490
115 390
87
75
57
130
78
59
-------
CO
co
Location/ Dates
7-30-71
7-31-71
8-1-71
8-2-71
Sample Designation
System Influent
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Effluent
System Influent
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Effluent
System Influent
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Effluent
System Influent
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Effluent
Time
1240
0845
1400
0845
1400
0845
1400
1130
0820
1310
0820
1310
0820
1310
1245
0825
1400
0830
1400
0845
1400
1405
0940
1410
0950
1410
0950
1415
ppm
Residual
pH Chlorine
7.9
8.5
8.5
7.7
7.8
8.5
8.8
7.0
7.5
7.7
7.5
7.6
9.0
8.8
9.0
7.5
8.3
7.6
7.6
8.5
8.7
7.7
8.5
8.5
8.5
8.5
8.3
8.8
Suspended
BOD5-ppm Solids Coliform
Total
330
160
230
86
125
105
110
1400
155
130
170
110
180
150
250
105
230
100
170
135
130
840
125
230
90
204
150
150
Dissolved PPm MPN col./lOOml
80 230
56
53
95
110
40
66
530 1240
45
100
75
50
36
23
290
55
95
105
65
60
50
280 460
70
70
160
175
205
105
-------
Location/Dates Sample Designation
8-5-71
8-7-71
8-8-71
8-9-71
System Influent
Carbon Column Inf.
Effluent 2nd Column
System Effluent
System Influent
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Effluent
System Influent
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Effluent
System Influent
Carbon Column Inf.
Carbon Column Inf.
Effluent 2nd Column
Effluent 2nd Column
System Effluent
System Effluent
Time
1300
1400
1400
1400
1215
1130
1420
1130
1420
1130
1420
1210
0820
1410
0820
1410
0820
1350
1225
0835
1410
0835
1410
0835
1410
ppm
Residual
pH Chlorine
8.2
8.6
7.8
8.8
7.8
8.5
8.5
8.3
8.3
8.6
8.6
8.6
8.8
8.9
8.2
8.3
8.6
8.7
8.0
8.7
8.8
8.2
8.1
8.7
8.6
16
-
29
13
26
-
-
22
22
-
-
13
13
15
25
-
-
!
BOD5-ppm
'i /tal Dissolved
1200 540
200
140
200
1200 510
190
195
200
180
195
200
360 160
130
220
43
56
53
56
990 4^ฐ
115
230
45
82
62
66
Suspended
Solids Coliform
ppm MPN col./ 100ml
-
-
-
-
-
-
-
_
- _
- -
- -
-
-
_
-
- _
-
-------
1 Accession Number
w
Subject Field & Group
SELECTED WATER RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
Organization
General Electric, Re-entry and Environmental Systems Division
Philadelphia, Pennsylvania
Title
Watercraft Waste Treatment System
Development and Demonstration Report
10
Authors)
Bryce, Arnold J.
Shelley, Peter S.
White, James C.
16
Project Designation
15020DHG
21
Note
22
Citation
Descriptors (Starred First)
25
Identifiers (Starred First)
27
Abstract
A demonstration program of electro-chemical processing of shipboard sanitary,
culinary, and laundry wastes including prolonged sea trials on board a large vessel was
conducted. Extensive analytical results are presented demonstrating ability to produce
effluent of secondary water quality standard and to inciperate system by-products. Sub-
stantial data for the design of shipboard systems is also presented.
The economic viability of the treatment system developed is analyzed and compared
with alternative approaches with the conclusion that dependence of large vessels on shore
side facilities in conjunction with on-board holding equipment is eliminated in many cases.
The program demonstrates the unique character of shipboard wastes and the shipboard
environment verifying the need for specially developed equipment for treatment such as the
system demonstrated.
The program suggests further extension of the capabilities of the system developed for
increase in capacity and for elimination of other ships wastes sunh as bilge water and wet
and dry garbage.
This report was submitted in fulfillment of Contract Number 14-12-522 under the
sponsorship of the Office of Research and Monitoring, Environmental Protection Agency.
Abstractor
James C. White
Institution
General Electric Company
WR:I02 (REV- JULY 1969)
WRSI C
SEND. WITH COPY OF DOCUMENT. TO: WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON, D. C. 20240
GPO! 1 970-389-930
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