EPA-660/2-73-020
DECEMBER 1973
Environmental Protection Technology Series
Information Resource:
Final Report Water Pollution
Control in Water Utilities
Office of Research and Development
U.S. Environmental Protection Agency
Washington, D.C. 20460
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Agency, have
been grouped into five series. These five broad
categories were established to facilitate further
development and application of environmental
technology. Elimination of traditional grouping
was consciously planned to foster technology
transfer and a maximum interface in related
fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL
PROTECTION TECHNOLOGY series. This series
describes research performed to develop and
demonstrate instrumentation, equipment and
methodology to repair or prevent environmental
degradation from point and non-point sources of
pollution. This work provides the new or improved
technology required for the control and treatment
of pollution sources to meet environmental quality
standards.
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EPA-660/2-73-020
December 1973
INFORMATION RESOURCE: FINAL REPORT
WATER POLLUTION CONTROL
IN
WATER UTILITIES
By
H. A. Faber
A. D. Nardozzi
M. J. Taras
Grant S800936
Program Element 1BB037
Project Officer
Harry F. Smith, Jr.
EPA, Region II
26 Federal Plaza
New York, New York 10007
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price $1.06
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EPA Review Notice
This report has been reviewed by the Environmental
Protection Agency and approved for publication.
Approval does not signify that the contents necessarily
reflect the views and policies of the Environmental
Protection Agency, nor does mention of trade names of
commercial products constitute endorsement or recommen-
dation for use.
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ABSTRACT
The goals of this effort were the collection, coordination, and
communication of information of a scientific, technical, and
administrative nature relative to control of pollution caused by
wastes from water treatment plants, in accordance with the re-
commendations of an industry advisory committee.
It covers laboratory tests underway or completed at widely
dispersed water treatment plants throughout the country on the
applicability of polymers as primary coagulants, coagulant aids,
and sludge conditioning agents, with the objective of alleviating
the problem of water treatment plant waste disposal. Also included
is the evaluation in cooperating laboratories of analytical
methods suitable for the physical and chemical examination of the
sludge and sludge solids from water treatment plants.
A total of 121 abstracts of technical articles were prepared on
the varied aspects of water treatment plant waste disposal: waste
problems at 26 named water treatment plants or geographical
locations, waste treatment in the new water treatment plants, water
conditioning practices, characteristics of alum, iron, and softening
wastes; treatment of filter washwater; treatment of sludge by the
reclamation of alum, lime, and magnesium carbonate, and by
dewatering processes involving centrifugation, drying beds, filter
pressing, freezing, and vacuum filtration; subsurface disposal and
disposal of brine wastes.
This report was submitted in fulfillment of Project 12120 EUR under
the partial sponsorship of the Environmental Protection Agency, in
cooperation with the American Water Works Association Research
Foundation.
Information concerning this project can be obtained from the author:
The American Water Works Association Research Foundation, 2 Park
Avenue, New York, N. Y. 10016.
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CONTENTS
Section Page
I Conclusions 1
II Recommendations ......... 3
III Introduction 5
IV Information Resource Activities . 7
V Technology Transfer . . 11
VI Polymer Evaluation Program ... 13
VII Literature Abstracts 16
VIII Acknowledgements 63
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TABLES
No. Page
1 Distribution of Reports 9
2 Polymer Products Under Evaluation 15
3 Classification of Literature Abstracts 17
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SECTION I
CONCLUSIONS
Need to Meet Waste Guidelines
The Water Pollution Control Act Amendments of 1972 authorize the
establishment of guidelines for all industrial discharges, including
those from the water utility industry. The attainment of the national
guidelines is envisioned as encompassing three well defined stages.
Industrial discharges must achieve as a minimum the best practicable
control technology by July 1, 1977, and the best available control
technology not later than July 1, 1983. The elimination of pollutant
discharges by 1985 is a national goal, with stream quality adequate
for the support of fish and wildlife by 1983 as an interim goal.
AWWA Research Foundation Contributions
Anticipation of this development prompted the American Water Works
Association Research Foundation in 1968 to begin collecting, coordinating,
and communicating the technical information which will enable the water
utility industry to fulfill its responsibilities with respect to the new
guidelines. This work was partially supported by grants from the Federal
Water Pollution Control Administration and the Environmental Protection
Agency. The Research Foundation has investigated all known technological
processes which are currently available or under development, and iden-
tified the areas still requiring further study and research. The complete
findings in these matters are detailed in two project reports issued in
1969 and 1971.
Waste Reclamation
New treatment plants often embody facilities for recapturing and
recycling filter washwater, both to minimize the waste disposal problem
and to secure the benefits of improved coagulation with a possible reduc-
tion in coagulant dosage.
Logic dictates that the reclamation of water treatment chemicals
such as alum, lime, and magnesium carbonate will eventually prevail in
many locations, as the long term solution to the waste disposal problem.
Reclamation will be required because the earth's resources are finite.
However, the necessary recycling facilities are still under development
and refinement, due to past neglect of this aspect of the problem. The
economics of by-product recovery are continually improving by virtue of
the escalating costs of transporting and handling solid materials. Ac-
cordingly, the movement of waste to distant landfills is losing its
former competitive advantage over recycling and recovery processes.
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Short and Long Term Solutions
Although reclamation facilities can be readily incorporated in new
water treatment plants during the design or construction stage, correc-
tive measures will be needed for plants now in operation. Unfortunately,
no single all-embracing technology is suitable for solving the short term
and long term waste disposal problem in every instance. The unit proc-
esses suitable for remedial applications include in-plant treatments
such as sedimentation tanks, concentrator chambers, settlement and thick-
ening tanks, and chemical conditioning; and mechanical dewatering devices
such as centrifuges, filter presses, vacuum filters, and draining and
drying beds. Other disposal practices involve dilution, sludge pumping,
discharge to sanitary sewers or lagoons, freeze-thaw, and land disposal.
All of these approaches have been successfully demonstrated at various
installations. The economics and demands of the local situation will
govern which process will be adopted for the short, intermediate, and
long term solution.
Polymer Coagulants
Supplementing the mechanical equipment needed to ensure compliance
with eventual guidelines, widespread investigations have been undertaken
by the water utility industry and chemical suppliers. Investigations
include studies of primary coagulants and coagulant aids which can
minimize dependence on the common inorganic coagulants, alum and iron
salts. Polymers offer a hopeful prospect for replacing inorganic coagu-
lants, reducing coagulant quantities needed for the clarification proc-
ess, and for conditioning the resultant sludge for easier disposal. This
class of substances may provide a short and/or long term answer in the
proper circumstances.
Ultimate Disposal
The most challenging problem in the control of wastes from treat-
ment plants is the disposition of the unwanted final product. There is
a limit on the amount of material that can be conserved and reclaimed.
A small quantity of presently unmarketable and useless residue remains at
the end of most recovery processes. Old plants lacking reclamation facil-
ities generate appreciable amounts of solid waste that often must be hauled
at considerable cost to remote sites, landfill and underground disposal,
together with barging to sea, are the practices most frequently utilized
for ultimate disposal of residual wastes.
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SECTION II
RECOMMENDATIONS
Compliance with Waste Guidelines
The American Water Works Association Research Foundation provides
a valuable vehicle for attainment of the quality guidelines authorized
by the Federal Water Pollution Control Act Amendments of 1972. The
eventual aim of zero discharge of pollutants and total environmental
control embracing water, solids, and air will be achieved by the contin-
ual improvement of the water treatment processes as well as the addition
of the proper waste treatment facilities.
The task assumes considerable proportions because an appreciable
number of water treatment plants are unequipped to meet the proposed
standards. The absence of prior legal compulsion to treat water plant
wastes, coupled with the failure to anticipate the meed by the installa-
tion of the necessary equipment during the original construction, are
at the bottom of the difficulty.
Present Technology for Meeting Guidelines
The American Water Works Association Research Foundation program
of collecting, coordinating, and communicating information of a scien-
tific, technical, and administrative nature relative to the control of
pollution caused by wastes from water treatment plants is the most
effective way of achieving this objective. A significant body of knowl-
edge has been assembled by the Research Foundation with respect to the
relative utility of the processes available for the treatment, reclama-
tion, and disposal of water treatment plant wastes.
Dewatering of sludge can be accomplished by the use of centrifuga-
tion, chemical and polymer conditioning, drying beds, filter pressing,
freezing, lagooning, sedimentation, thickening, and vacuum and precoat
filtration. A survey of the equipment fabricated by more than 100
manufacturers is needed on the products designed to dewater sludge or
treat water plant wastes. This information will prove invaluable to
utilities operating old plants currently in violation of pollution
regulations.
Recovery processes are available for treatment chemicals such as
alum, brine, lime, and magnesium carbonate. Reclamation is an attrac-
tive concept which is destined to command increasing attention because
of the minimal discharge of pollutants to the environment. The adop-
tion of reclamation processes in new and old installations should be
promoted wherever possible.
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Polymers afford a promising field of investigation by virtue of
the reduction in the sludge volume which they can effect through re-
placement or supplementation of common coagulants such as alum and
iron salts. The fact that polymers can be custom tailored for a
particular water supply offers hope for the development of a sufficient
number with useful properties. Laboratory tests of polymers are now
underway as a part of studies conducted by the Research Foundation in
widely dispersed water treatment plants throughout the country. These
tests will evaluate the applicability of polymers as primary coagulants,
coagulant aids, and sludge conditioning agents. The results of these
tests must be evaluated, and expanded studies may be required.
Future requirements
All technology is subject to improvement from the standpoint of
economics and material effectiveness. The ideal development would be
a single, inexpensive, and easily processed coagulant to fit all water
treatment situations. Since the world is not tailored of such simple
cloth, unremitting research is needed into new chemical and treatment
methods.
The reclamation and recycling of chemicals, and the application
of polymers as primary coagulants, coagulant aids, and sludge condi-
tioning agents afford possible solutions to the waste disposal problem
and should be subjected to intensive investigation.
Landfill and underground disposal, together with barging to sea
should be investigated further to learn their advantages versus their
shortcomings as methods of ultimate disposal.
The control of waste discharges underscores the need and importance
of developing a standard methodology for the sampling and analysis of
sludge and sludge solids. Such methods are needed for the reliable
measurement of the effectiveness of current and future treatment proc-
esses. The presently available analytical methods for the physical and
chemical examination of sludge and sludge solids require further evalua-
tion in cooperating laboratories before general acceptance can be assured.
The AWWA Research Foundation will promote and contribute to the
development of research in these and similar areas. As a clearinghouse
for information, the Foundation will serve to transfer the new technology
to the water utility industry as promptly and as effectively as possible.
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SECTION 111
INTRODUCTION
Recent national legislation spells out the evolutionary stages of the
water pollution control program. Wastes from the water utility industry
come within the jurisdiction of this legislation.
Although new water plants can be designed with adequate facilities to meet
the legislated requirements, old plants may have difficulty accommodating
to the effluent standards. These problems were foreseen during the
creation of the American Water Works Association Research Foundation and
one of the first research projects to be undertaken was the problem of
coping with water treatment plant wastes. This study was supported in
part by a grant from the Federal Water Pollution Control Administration
and embraced known treatment technology, cost data, and suggestions for
future needs. The project findings, were incorporated in the report
entitled "Disposal of Wastes from Water Treatment Plants" published in
1969. The report urged the establishment of a central information
clearing-house to organize, coordinate, and disseminate information on
new or modified treatment technology and promote its application by the
water utility industry.
A grant from the Water Quality Office of the Environmental Protection
Agency, together with matching funds from 30 water utilities, enabled
the fulfillment of this recommendation. A project advisory committee,
composed of experts actively engaged in the research, engineering, plant
operation, and regulatory aspects of the sludge disposal problem, was
assembled for a two-day meeting. The committee members were encouraged
to exchange ideas and offer suggestions for the organization of an
information service.
Implementation of their recommendations has resulted in the accumulation
and dissemination of current research information and criteria of value
in the solution of specific problems at individual water utilities.
A search of the pertinent literature has revealed the research and
development activities underway in government agencies, water research
institutions, and the water utility industry. A substantial number of
technical articles have been abstracted in accordance with Water Resources
Science Information Center specifications for inclusion in their comput-
erized storage and retrieval system.
Surveys were undertaken among regulatory agencies and water treatment
plants. The findings of the regulatory surveys provided new insights
into treatment requirements, acceptability of sludge disposal methods,
maintenance and reporting of waste production records, and the support
and conduct of research. The water utility surveys underscored a need
for standard methods for sampling, examining, and categorizing waste
materials from water treatment plants. A subcommittee was appointed to
develop such laboratory methods applicable to all types of water treatment
plant wastes.
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A polymer evaluation program was also initiated to determine the
applicability of polymers as primary coagulants, coagulant aids, and
sludge conditioning agents.
The publication of this information should stimulate further research
into these important sectors. '
The project advisory committee concluded that there is no single
universally acceptable treatment for conventional and softening sludges,
and that a variety of treatment alternatives will require evaluation on
a local basis wherein efficiency, operation and maintenance requirements,
and economics will play their proper roles.
This synopsis can only touch upon the highlights of the two previous reports
on this project published in 1969 and 1971. The original reports must
be consulted for background details, and, in fact, must be considered the
foreword to this report.
Copies of earlier reports referred to are available:
(1) "Disposal of Wastes from Water Treatment Plants" 1969
Report, 78 pages. Reprint from the JOURNAL OF THE AMERICAN
WATER WORKS ASSOCIATION, available from the American Water
Works Association Research Foundation, 2 Park Ave., New
York, N.Y. 10016.
(2) "Information Resource: Water Pollution Control in the
Water Utility Industry" 1971 Report, 169 pages.
U.S. Environmental Protection Agency, Water Pollution
Control Research Series, 12120 EUR, 11/71. For sale by
Superintendent of Documents, U.S. Government Printing
Office, Washington, D.C. 20402, Price $1.50.
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SECTION IV
INFORMATION RESOURCE ACTIVITIES
The water utility industry of the United States needs direction
and guidance in controlling waste discharges from water treatment plants,
The American Water Works Association Research Foundation provides the
mechanism for collecting, synthesizing, and disseminating information
designed to promote the efficient development and application of tech-
nology for pollution control by the water utility industry. These ob-
jectives are accomplished by the collection and transfer of technical
data on disposal of water treatment plant wastes, the compilation of
abstracts and indexes of the pertinent technical literature, and by
special studies of new technology.
Research Foundation Clearinghouse
The clearinghouse function conducted by the Research Foundation
consists of gathering and classifying all information on research,dem-
onstration, and plant scale projects completed, in progress, or pro-
jected. Important parts of this effort include:
Updating of cost data, the accumulation of basic data on the
quality and quantity characteristics of waters from water
treatment processes, and studies of their pollutional effects.
Determination of immediate and long-range needs for basic and
applied studies, and for plant scale demonstration projects.
The assembled information is coordinated, analyzed, and trans-
lated into a form that facilitates its application in research
and 'demonstration projects.
A Project Advisory Committee, representing a variety of scientific,
engineering, and administrative disciplines, assists in the development
and analysis of the most useful data.
One purpose of these activities is to encourage cooperation between
investigators in educational institutions, governmental agencies, and
water utilities. Another aim is to acquaint academic researchers with
practical applications so that their investigations can be designed to
achieve maximum benefit.
The ultimate goal is the development of effective and economical
methods for the treatment and final disposal of the substantial quantities
of solid wastes emanating from the water utility industry. The offending
wastes include those from filter backwash and ion exchange brines, and
from the coagulation, softening, iron .and manganese removal, diatomaceous
earth filtration, and desalting processes.
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Transfer of Information
Efficient and speedy communication of information is essential to
keep the research sector conversant with current projects and problems,
and to advise the water utility industry regarding new developments in
the disposal of wastes from water treatment plants.
As a central resource for organization and coordination, the Research
Foundation conducts extensive correspondence with scientists, engineers,
administrators, and manufacturers in the United States and abroad on the
subject of new information and improved technology for the disposal of
wastes from water treatment plants. Periodic articles are published in
technical journals and progress reports are delivered at meetings of
AWWA Sections.
Since its inception, the Research Foundation clearinghouse has ini-
tiated and maintains contact with a total of 740 individuals in the
following organizations and specialized technical categories:
Chemical Suppliers
Consulting Engineers
Educational Institutions
Equipment Manufacturers
Governmental Agencies
Municipal Water Utilities
Science Information Exchange
State Water Resources Research Institutes
Foreign Institutions and Agencies, including
the British Water Research Association and
the International Water Supply Association
Numerous inquiries by phone and letter are answered from these and
other interested individuals during the course of the year. The availa-
bility of these services have been publicized in the JOURNAL AWWA, WILLING
WATER, NEWSLETTER, and in trade publications.
Technical Developments Underway
In addition to the material gathered through literature searches,
valuable unpublished information has been accumulated by correspondence
and personal contact with individuals who are conducting applied research.
Significant work of this nature is being performed by consulting organiza-
tions which are engaged in comprehensive laboratory, pilot plant, and full
plant-scale studies.
The following processes and equipment for treating and dewatering
water plant wastes are being subjected to such evaluation: chemical coagula-
tion, freeze and thaw by continuous mechanical means, centrifugation with
basket and solid bowl of raw sludge and chemically treated sludge, filter
pressing of both raw and chemically treated sludge and vacuum filtration of
both raw and chemically treated sludge.
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Consulting firms are also investigating the build-up of color,
turbidity, heavy metals, and other constituents which results from
the use of acid-recovered alum in water treatment.
The abstracts and the original papers and articles in the Research
Foundation files are a valuable resource to engineers and researchers
active in the waste disposal field. Considerable time is saved in
literature searching by reference to the two previous project reports
and the continually updated abstract file. Papers, published and un-
published, by foreign authors hold a special attraction because of
their limited availability in this country.
Distribution of Reports
All of the studies completed since the inception of the project in
1968 are delineated in two reports prepared by the Research Foundation,
each of which has had a circulation in excess of 1,000 copies. At the
request of the Environmental Protection Agency, the Research Foundation
has also distributed to its specialized mailing list reports on the
actively supported project involving the application of magnesium car-
bonate as a recycled coagulant.
The total distribution of these reports is presented in the following
table:
TABLE 1
Distribution of Reports
Copies Mailed Title of Report
1100 "Disposal of Wastes from Water Treatment
Plants". Water Pollution Control Research
Series. 12120 ERC (August 1969).
1025 "Information Resource: Water Pollution
Control in the Water Utility Industry".
Water Pollution Control Research Series.
12120 EUR 11/71-
840 "Magnesium Carbonate, A Recycled
Coagulant for Water Treatment". Water
Pollution Control Research Series. 12120
ESW 06/71
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Reports at Technical Meetings
Papers on the disposal of wastes from water treatment plants were
delivered by the Research Director at meetings of AWWA Sections in
Illinois, Iowa, Ontario, and Pennsylvania, as well as at the 1972 AWWA
Conference. Five technical papers on the disposal of water treatment
plant wastes were a feature of the Water Quality Division session at
the 1972 AWWA Conference held in Chicago.
A discussion on the disposal of alum sludge wastes from water
treatment plants in the U.S.A. and the activities of the AWWA Research
Foundation was presented by the Research Director at the Ninth Inter-
national Water Supply Congress and Exhibition on September 14, 1972
in Hew York City.
JOURNAL AWWA Issues
During 1972 the Research Foundation played a principal role in
compiling two full issues of the JOURNAL AWWA. The October issue
dealt with the general area of water treatment research, including
the disposal of plant wastes. The November issue encompassed all
phases of desalination including waste disposal. A third issue
scheduled for publication during the summer of 1973 will focus on
water treatment plant sludge and contain the papers presented at
the 1972 AWWA Conference in Chicago together with additional germane
contributions.
Project Relation to EPA
The Research Foundation has also been invited to assist the Engineer-
ing and Sciences staff of the Environmental Protection Agency located in
Cincinnati, in the preparation of effluent guidelines for water treatment
plant wastes. The objective will be the formulation of guidelines on a
progressively restrictive basis from the current average results to zero
discharge as specified in recently enacted national legislation.
The Research Foundation1s continuing study of water treatment plant
waste disposal was deemed relevant in reviewing the over-all problem,
determining the need for research and demonstration, investigating the
achievement of current waste treatment plants, and establishing monitoring
procedures for waste discharges.
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SECTION V
TECHNOLOGY TRANSFER
Research currently conducted on the disposal of wastes from water
treatment plants is, unfortunately, not in proportion to the magnitude
of the problem. The number of ongoing investigations in academic in-
stitutions and water utilities, and conducted or supported by govern-
mental agencies, is relatively small. Much of the research completed
or underway is directed toward the removal of water from sludges, and
little research has been directed to problems of ultimate disposal.
In keeping with its objective to explore acceptable ways of all-
eviating the sludge disposal problem, the AWWA Research Foundation has
contributed support to the pilot plant study and currently the plant
scale study at Montgomery, Alabama, involving the use of magnesium car-
bonate as a recycled coagulant for water treatment. The process dis-
places filter alum and enables the repeated use of magnesium carbonate
and lime once the proper processing facilities have been installed and
placed in operation. Favorable results on a plant level will justify
extending trials to other plants around the country. The Research
Foundation will encourage this effort and publicize the operational
data when they become available.
During February 18-21, 1973, a Research Foundation staff member
traveled to Montgomery, Alabama to participate in a three-day seminar-
workshop on the magnesium carbonate water treatment system. The lectures
were delivered on the campus of Auburn University of Montgomery, and
the demonstrations were conducted at the Montgomery water treatment
plant. The Montgomery project is jointly supported by the Environmental
Protection Agency, the City of Montgomery, and the AWWA Research Founda-
tion.
The lectures explored the problems created by water treatment plant
sludge and the views of regulatory agencies with respect to polluting
discharges, the history and basic concepts of the magnesium carbonate
system. Presentations included flow diagrams, pertinent chemical reac-
tions, preliminary laboratory studies^ and the economic optimization
of the process. A computerized evaluation was offered on the cost of
the various unit operations alongside of the actual costs. Emphasis was
placed on the applicability and advantages of the magnesium carbonate
system for turbidity and color removal, softening, and the recovery of
magnesium, lime, and carbon dioxide in both new and old installations.
Two visits were made to the Montgomery water treatment plant for an
inspection of the facilities required by the magnesium carbonate recycling
system and the concomittant laboratory and plant controls. Special atten-
tion was directed to the magnesium recovery and dewatering operations
involving carbonation cells, thickener, vacuum filtration, and sand drying
bed.
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The following advantages of the magnesium carbonate system were
cited by Dr. A.P. Black at the conclusion of the seminar-workshop:
The coagulant can be recycled and reused, thereby providing
an economical and practical solution to the sludge disposal
problem, concurrently with a reduction in chemical treat-
ment costs.
The increased settling rate of the magnesium hydroxide and
calcium carbonate floe enables a higher clarifier loading
rate and an improvement in the filtrability of the settled
water.
The finished water is noncorrosive and stabilized by pH
control.
The 11.2 - 11.5 pH range used to produce the magnesium
hydroxide floe inactivates most viruses and destroys bac-
teria, thus minimizing the need for prechlorination.
The system is simple to operate and automate, and entails
no important physical changes in existing treatment plants.
Hard waters provide an opportunity to reduce operating costs
through lime recalcination and the production of magnesium
carbonate from the sludge for external sale.
The Research Foundation has recently assisted Dr. Black in his
efforts to publicize the advantages of the magnesium carbonate coagulant
process. He has been provided with the names and addresses of the re-
sponsible officials in 33 water departments throughout the nation. These
officials will be invited to attend a meeting designed to expand the
availability of technical information on the process.
The AWWA Research Foundation has supplied pertinent information to a
public water utility which is contemplating the recalcination of its
softening sludge. A copy of Dr. Black's publication MAGNESIUM CARBONATE,
A RECYCLED COAGULANT FOR WATER TREATMENT was also forwarded to the utility
for consideration of the new process as an alternative to recalcination.
The magnesium carbonate technology appeared applicable in the circumstances
and deserved serious study as an all-embracing water treatment for that
supply.
Dr. A.P. Black's report entitled "Magnesium Carbonate, A Recycled
Coagulant For Water Treatment,"Water Pollution Control Research Series,
Project 12120 ESW, 06/71, is available at a cost of $1.00 from the
Superintendent of Documents, U.S. Government Printing Office, Washington,
D.C. 20402.
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SECTION VI
POLYMER EVALUATION PROGRAM
The favorable prospects for application of polymers in water treatment
are succinctly enumerated in the Report of the AWWA Water Quality
Division Committee on "Disposal of Water Treatment Plant Wastes",
published on pages 814-820 of the December 1972 issue of the JOURNAL AWWA.
The following excerpts from the report describe the multiple advantages
of Hie polymers with respect to the disposal of water treatment wastes:
"With the new and improved organic polymers available today
it may be possible to reduce or even eliminate the use of
alum or similar coagulants used for water clarification. In
some instances, where raw water quality permits, the application
of minute dosages (10 to 30 parts per billion) of a polyelec-
trolyte to the filter influent water may suffice to produce a
good quality of filtered water without the need for prior coagu-
lation. In others, where coagulation is necessary, very few
dosages (0.2 to 3 parts per million) of the proper polyelec-
trolytes may effectively take the place of much larger dosages
of alum (or similar chemicals) as the primary coagulant.
Substitution of polyelectrolytes for the more commonly used
coagulants would not only reduce the quantity of sludge developed
but would also produce a sludge more amenable to dewatering or
other processing for reduction in volume. The sludge would also
be more suitable for incineration as a result of the substitution
of organics for the non-combustible inorganic coagulants. An
additional benefit could be reduction in cost of chemicals for
treatment as the substantial reduction in dosages required may
offset the higher unit cost of polyelectrolytes1'
The value of polymers as flocculants and coagulant aids in the water
treatment field was emphasized at the International Water Supply
Association Congress and Exhibition held on September 14, 1972 in New
York City. The consensus based on European experience was that polymers
definitely warrant continuing study.
Although polymers admittedly do not represent a panacea for all the
problems besetting water treatment, they may provide an answer in some
localities. The incidence of success and failure, and the advantages
and limitations should be ascertained before a general assessment is
attempted. The first logical step in such a direction is a laboratory
evaluation program which encompasses varied water supplies throughout
the country, and is based on an accepted standard jar test procedure.
The AWWA Research Foundation has developed a program of laboratory
evaluations, now underway in such widely dispersed geographical regions
as the eastern seaboard, the midcontinent, and the far west. The eleven
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laboratories are evaluating a total pf 46 polymers supplied by eleven
manufacturers, consisting of primary coagulants, coagulant aids, and
sludge conditioning agents. The specific polymers under test are
identified in Table 2. Each of the ten water department laboratories
in the project £re evaluating eight to fifteen polymers in the treatment
of their own water supply, with the average number approximating ten
polymers.
Since the commencement of the evaluation program, significant operator
interest has been evidenced in polymers capable of functioning as
primary coagulants. The major manufacturers are endeavoring to supply
this demand with a maximum research and development effort in this
direction. The Research Foundation has arranged to distribute the
emerging and as yet unmarketed products for laboratory evaluation
among interested operators. Such a procedure should benefit both
suppliers and operators by identifying the polymers with the broadest
potential prior to their formal commercial introduction.
A questionnaire mailed to each participant relative to the beginning
and completion dates of their laboratory tests suggests that the final
results might realistically be excepted about the summer of 1973.
The data submitted to the Research Foundation on prepared forms will
be tabulated, summarized, and interpreted. The useful findings emerging
from the project will be publicized in the professional journals as a
contribution to the adoption of this new technology.
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TABLE 2
Polymer Products Under Evaluation
By AWWA Research Foundation
American Cyanamid Co.
Magnifloc 521C
Magnifloc 570C
Magnifloc 845A
Magnifloc 860A
Magnifloc 972H
Magnifloc 985N
Magnifloc 990N
Betz Laboratories
Poly-Floe 1100
Poly-Floe 1110
Poly-Floe 1120
Poly-Floe 1130
Poly-Floe 1150
Poly-Floe 1160
Poly-Floe 1175
Poly-Floe DK-483
Burtonite Co.
Burtonite #78
Calgon Corp.
Cat-Floe
Cat-Floe B
Coagulant Aid 233
Coagulant Aid 235
Coagulant Aid 243
Coagulant Aid 253
Dow Chemical Co.
Purifloc A23 (Potable Water Grade)
Purifloc C31
Purifloc C41
Purifloc N17
Purifloc N20
Gamlen Chemical Co.
Gamlose W
Hercules Inc.
Hereofloc 812.3
Hereofloc 815.3
Hereofloc 818.2
Hereofloc 821.2
Hereofloc 827.3
Hereofloc 831.2
Hereofloc 834.1
1CI America (Atlas Chemical Co.)
ATLASEP 2A2
ATLASEP 3A3
ATLASEP 4A4
ATLASEP 105C
Nalco Chemical Co.
Nalcolyte N-607
Narvon Mining & Chemical Co.
Zeta Floe C
Zeta Floe 0
Zeta Floe WA
Philadelphia Quartz Co.
Polymer XP-233C
Polymer XP-800N
Polymer XP-950A
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SECTION VII
LITERATURE ABSTRACTS
The AWWA Research Foundation, as a central information resource, collects,
abstracts, and indexes all available literature on the treatment and
disposal of wastes from water treatment plants. The abstracts conform
with the specifications of the Water Resources Science Information Center
(WRSIC), which reviews, edits, and stores the abstracts in a computerized
system for ready retrieval. The abstracts are published by the Office
of Water Resource Research, U.S. Dept. of the Interior, in Selected Water
Resources Abstracts.
The Research Foundation has assembled and reviewed technical Articles
from a variety of sources. These sources include: papers delivered at
national and local AWWA section meetings; articles identified through
literature searches; and articles transmitted to the staff by members of
the advisory committee, and practitioners in the engineering, plant
operation, and research fields.
The 121 abstracts which appear on the following pages present capsule
summaries of technical articles on water plant waste treatment. For
convenience, the abstracts are grouped by their original title under
broad general headings. In many cases, a paper may provide valuable
information encompassing a wide area of inquiry and endeavor. For
this reason, examination should be extended to other headings to note
such possibilities. The classification title of "Waste Problems at
Specific Water Treatment Plants" might prove rewarding in this respect.
The 121 abstracts prepared during the course of this project phase,
coupled with the 72 published in the 1971 Report brings the total
collection to 193. The original papers are on file at the American
Water Works Association Research Foundation for inspection or can be
copied and mailed at the cost of handling.
The abstracts are arranged under the following classifications.
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TABLE 3
CLASSIFICATION OF LITERATURE ABSTRACTS
Class i fication Page
Waste Problems in Specific Water Treatment Plants 18
Waste Treatment in New Water Treatment Plants 28
Water Conditioning Practices 29
Water Treatment Plant Wastes
Review Articles 31
Committee Reports 33
Characteristics of Wastes 34
Treatment of Filter Washwater 35
Treatment of Sludges
Chemical Recovery Processes .... 37
Alum, Lime, Magnesium Carbonate, General
Dewatering Processes 42
Centrifugation, Drying Beds, Filter Pressing,
Freezing, Vacuum Filtration, General
Sludge Conditioning . 48
*
Types of Wastes 49
Alum, Iron, Softening, General
Miscellaneous Processes 55
Disposal Methods
Brine Wastes , 57
Subsurface 58
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WASTE PROBLEMS IN SPECIFIC WATER TREATMENT PLANTS
Almquist, F.O.A., "Problems in Disposal of Sludge and Washwater for^Connecticut Water
Filtration Plants", Journal NEHWA. Vol. 60, No. 4, pp. 344-358, December 1946.
Key Words: Lagoons, Waste dilution, Filter sashwater, Basin sludge, Drying beds
Review of data from sludge analysis at purification facilities discussing plant problems and
possible remedies. Physical and chemical sludge data are tabulated and bacteriological tests
reported. Six treatment plants using alum coagulants found different sludge handling solutions.
Three plants lagooned this waste and decanted the supernatant. Sludge drying beds with 4"
underdrains topped by graded gravel and sand dewatered filter washwater and basin sludge at.
one utility. One plant discharged to a meadow while another plant transported by pipe to a
larger receiving stream for dilution. Eleven plants diluted their waste. A table of practice
in cleaning basins showed cleanings per year, disposal methods, complaints, and remarks for
17 plants. Author suggests additional remedies and need for further research.
Ash, R.V. "The Great Eau Scheme: North-East Lincolnshire Water Board", Journal of the
Institution of Water Engineers. Vol. 20, No. 7, pp. 435-458, October 1966.
Key Words: Water purification, Water softening, Sludge treatment, Design details
Study reports initial investigation and design details for the intake works, treatment
processes, and aqueduct for a water supply system, ^he cost of the scheme was estimated at
4.3 million pounds. Quality data are presented for color, hardness, chlorine, and iron and
manganese content of the raw water. Proposed treatment included: cascade aeration; precipitators
with mechanical flocculators and upward flow for partial or split softening and clarification;
rapid gravity filters; stabilization; and disinfection with breakpoint chloririation. Details
are provided on the clear water reservoir, chemical storage and dosing system, and washwater
recovery and sludge disposal. The 40,000 gallon tanks, equipped with agitators, store wash-
water. The sludge from these tanks is sent to the precipitators. Precipitation sludge is
concentrated in slow stirring thickeners with supernatant water returned to the precipitation
inlet. Sludge is pumped to sea.
Carter, R.C., Ludwig, H.F., Ongerth, H.J., Harmon, S.A. & Woody, S.H., "Behavior and Evaluation
of Microstraining for a Supply in California", Journal AWWA. Vol. 54. No. 5, pp. 606-620, May 1962.
Key Words: Filtration, Microstrainer
Description of the installation of a microstrainer and details of a method to evaluate its
performance. The water source increased in turbidity and coliform organisms. A 10-foot
diameter by 10-foot microstrainer was installed and provisions made for 3 more. Automated
operation parameters included: 30-100 fpm drum speeds; 35-100 gpm backwash flow rates at
pressures of 15-25 psi; and use of ultra-violet light to reduce bacterial slime on the
stainer fabric. Particulates were classified in size groups according to type and composition.
A relationship was developed to calculate the size of the average volume particulate. An
average particulate volume index of 25 /u tfr larger means excellent removal. The report concluded:
the removal efficiency of particulates improves with increased total volume or large average
particulate volume debris particles, comprising an agglomerated mixture of materials, diatoms
and organic debris, tend to disperse during microstraining; and straining reduces chlorine
demand appreciably and may effect some coliform removal.
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Cartwright, F., "Design of Farmoor Treatment Works, Oxford Corporation Water Department",
Journal of the Institution of Water Engineers. Vol. 18, No. 5, pp. 381-412, August 1964.
Key Words: Water purification, Sludge treatment, Design considerations
This study reviewed the problems and design considerations for the four stage development of
a 24 mgd water purification plant. A reservoir is planned to furnish an adequate raw water
supply. Advantages and disadvantages of the treatment site are discussed. The source water
is stable and non-corrosive, but prone to periodic taste and odor problems. Physical and
chemical water characteristics are tabulated. The plant layout included: aerator, micro-
strainers; settling tanks; filters; pump and control housing; treated water storage reservoir;
chemical house; administration building; electrical substation; diesel house; garage and
cycle shed; dirty washwater and sludge settling tanks; sludge settling lagoons; automatic
controls; alarm system; and oil-fired burner. Some contract cost and design specification
data are provided. These data described the facilities enumerated under the plant layout.
Thickened sludge is settled in a lagoon... Decanted supernatant is discharged to a nearby
brook. Duplicate filter washwater tanks and sludge thickening tanks are provided.
Collins, P.G.M. & Gibb, 0., "Design and Construction of the Fixby Water Treatment Works for
Wakefield and District Water Board", Journal of the Institution of Water Engineers, Vol. 18,
No. 6, pp. 491-502, October 1964.
Key Words: Sludge treatment, Water purification, Site selection, Construction details*
The article reviewed site selection criteria, proposed treatment methods plant operation and
construction details, and washwater and sludge treatment processes for a 7 mgd water treatment
plant. The treatment facilities included: ferrous sulfate coagulation; pH conditioning;
hydraulic mixing; mechanical flocculation; upflow sedimentation; breakpoint chlorination;
rapid gravity filtration; automatic residual chlorine control; filtered water storage; and
waste handling facilities. Filtration flow rates are 101-121 gallons/sq ft/hr through a
graded quartz sand bed on graded gravel with a perforated asbestos cement pipe underdrainage
system. Filter washwater is settled in duplicate recovery tanks of 60,000 gallons capacity.
Supernatant is recycled to the plant inlet. Concentrated sludge is periodically withdrawn
and pumped to lagoons for drying and ultimate disposal. Sludge lagoons are an interim
treatment measure. Chemical handling facilities are described. Building and general layout,
and structural design details of the clear-water reservoir, precipitators, filters, and
ancillaries are presented. Concrete mix and design data are listed. Appendices included
contractors and design and administration information.
Dittoe, W.H., "Disposal of Sludge at Water Purification and Softening Works of the Mahoning
Valley Sanitary District", Journal AWHA. Vol. 25, No. 11, pp. 1523-1530, November 1933.
Key Words: Water purification, Water softening, Holding ponds
This study explained the elements entering into the design and operation of sludge holding
ponds. The 40 mgd treatment facility employs purification and lime-soda ash softening with
filtration. Lime, soda-ash, and alum are mixed with raw water. The precipitates settle
and the process water is carbonated. There is sludge recirculation prior to filtration and
continuous sludge removal. Sedimentation tank sludge is settled in two ponds, each holding
one year's sludge production. Waste supernatant will overflow to the river, evaporate, and
seep into the ground. Tabulations are presented for sludge produced in treatment and the
volume and percentage of water in one ton of sludge. Sludge is pumped 1300 feet in 4 inch
line to the ponds. Decantation equipment is provided in each pond. A pond supernatant
less than 15 ppm turbidity is disposed in a creek. Solids removed may be used in soil
treatment. The ultimate success of disposal depends on how effectively sludge utilization
can be promoted.
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Doe, P.W., "The Design of Washwater and Alum Sludge Disposal Facilities for Passaic Valley
Water Commission", Paper presented at Annual AWWA Conference June 6, 1972, Chicago, Illinois.
Key Words: Filtration, Filter press
In 1967, the Passaic Valley Water Commission intitiated a program to review all aspects of
water treatment plant sludge disposal. Filter pressing appeared most promising. A Beloit-
Passavant press was used for pilot plant studies. Preliminary data was developed to establish
waste sludge quantity of filter washwater and sedimentation basin material. A backwash settling
tank was designed to: settle the suspended solids and return the supernatant overflow to the
plant inlet; or collect backwash water, mix it, and return the mixture to the plant inlet to
provide sites for coagulation. Polymer is added. The sludge thickening complex will treat
sedimentation basin sludge and underflow from the backwash settling tanks. Sludge is stored,
centrifuged, and conditioned with lime before filter pressing. The filter cloths are precoated
to produce an easily stripped cake. Each press has a 220 cubic foot capacity. EPA has not
approved construction funding for this flexibly designed facility.
Earnshaw, F., "Design of the Yorkshire Derwent Headworks", Journal of the Institution of
Water Engineers. Vol. 16, No. 2, pp. 139-159, March 1962.
Key Words: Water Softening, Sludge treatment. Specifications
This study outlined treatment plants for a 25 mgd water softening facility. The intake site
for the tidal source was chosen for: minimal interference to the freshwater regime; ability
to provide water and avoid heavy silting; and a foundation suitable for construction of a
pump house and treatment works. Flow occurrence probability records and formulae are presented.
Treatment included: lime (lime-soda) softening in upward-flow reaction tanks with clarification
aided by a coagulant useful at high pH values; stabilization and chlorination in a baffled
contact tank; rapid gravity filtration; dechlorination and ammoniation; treated water storage.
The nature of the site, layout of the works, and preemptory specifications for the intake
and low-lift pumps are provided. Details are discussed for the reaction tanks, flash mixer
and contact tank, filters, and automatic controls. The controls will monitor: raw and
treated water flow, river levels, intake system condition, chemical handling and storage
facilities, and filter washing. Consideration is being given to sludge dewatering by centri-
fugation. It is thought the sludge has agricultural value. Permanent sludge dump sites
include unused gravel pits and quarries, and abandoned canal, and an estuary. Sludge will be
lagooned on site for the first 12 months of operation while handling methods are evaluated.
Evans, G.R., "Discussion On Use of Microstrainer Unit at Denver", Journal AWWA. Vol. 51,
No. 3, pp. 358-362, March 1959.
Key Words: Filtration, Microstrainer
This discussion provided data on the microstrainer construction, washing process, operating
results, and applications. Strainer flow rates of 30 gpm/ft^ have been reached. Flow
depends on the mesh fabric apertures and raw water suspended solids concentration. Filter-
ability index, flow volume, rotational drum speed, fabric area, and head loss are interrelated
variables that must be considered in design. Water pressure for washing is a function of the
incoming raw water quality, drum speed and fabric mesh. Average wash water pressure was 18-
20 psi with 35 psi a maximum. Wash water averaged 1.7% of through flow. Occasional cleaning
of the mesh with a 12-15% sodium hypochlorite solution was required in the summer when
Asterionella predominated. Operating results for this and other plants are discussed. Nearly
100 installations were cited in construction or operation. Microstraining has become a sole
filtration process in both public and industrial supplies. This process can serve as a
primary treatment ahead of rapid sand filters in a manner similar to installation in front
of slow sand filters.
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Forster, Hans, "Test Results on Basin Sediment From the Chattahoochee Water Treatment Plant,
City of Atlanta. Ga.", Private Communications, January 1970.
KeyWordst Filter pressing, Alum sludge
The City of Atlanta purchased Beloit-Passavant Sludge Dewatering Equipment to dewater the alum
sludge generated at the Chattahoochee Water Treatment Plant. The purchase of this equipment
followed extensive testing in which air flotation, vacuum filtration, centrifugation, and
filter pressing processes were carefully evaluated. This will make Atlanta the first United
States city to dewater alum sludge by filter pressing on a plant scale basis. Seven new
filters are under construction that will increase the plant design capacity to 60 mgd. The
full scale plant will consist of two series 6400 Beloit-Passavant Pressure Filters. The
presses are expected to produce a filter cake with a solids concentration between 40 and 45%.
The alum sludge will be conditioned with lime before processing. The filter cake can be
disposed of as a landfill. The capacity of the two filters being installed is approximately
55,000 pounds of dry solids daily. It is expected that the Chattahoochee Sludge Dewatering
Plant will go into service late 1971. For additional information, contact Mr. Hans W. Forster,
Product Manager, Beloit-Passavant Corporation, Carson Road & Hwy 79 N.W., P.O. Box 2503,
Birmingham, Ala. 35202.
Fujita, H., "Tokoyo's Asaka Purification Plant", Water & Sewase Works. Vol. 14, No. 3,
pp. 73-82, March 1967.
Key Words: Water purification, Alum recovery, Washwater recovery
This study outlines design and construction data for a $73.5 million purification plant
treating a raw water with normal turbidity 10-50 ppm, COD 1 ppm, and manganese 0.1-0.3 ppm.
Features include: space-saving layout and structure; unique sedimentation basins; deep-well
underground buildings; huge pump installations; and supervisory control system. Details
are provided on the raw water intake and conveying facility; receiving well and sedimentation
basins; rapid sand filters; administration house and clear water pumping station; clear
water reservoirs; chemical plant; power supply installation; and washwater and sedimentation
basin sludge disposal system. Washwater is settled in 1.2 million gallon basin and returned
to the receiving well by wash-waste pumps to recover 26-53 mgd of water. Sedimentation of
sludge is concentrated and dewatered in the plant. Sulfuric acid is added to the sludge.
Alum is recovered for reuse. Thickened inert material is vacuum filtered with the cake used
for landfill.
Gordon, F.G., "Economics of Sludge Removal from Rectangular Basins at Chicago", Journal AWWA,
Vol. 48, No. 9, pp. 1125-1132, September 1956.
Key Words: Economics* Manual cleaning, Mechanical sludge removal
This study compared the economy and efficiency of manual and mechanical sludge removal
methods on plant operation. The basins were double-decked rectangular parallel-flow units.
Detention times and flow velocities are tabulated for the 320 mgd facility. The utility
of scapers in the entire settling basin could reduce the shutdown time for cleaning, necessary-
inspections and maintenance by 60 days. Data are presented for complete mechanical sludge
removal and the relationship of microorganisms and turbidity in settled water to average filter
run lengths. The installation and operation of mechanical sludge removal equipment in one
third of the basin reduced the amount of drained sediment requiring manual cleaning. Complete
sludge removal equipment could decrease shutdown time from 20 to 4% per year. Complete removal
equipment was unjustified because the net annual increase in operating expenses and fixed
charges was $ 72,420. The plant operation was not impaired by sludge accumulation in the
settling basins. Filter run length was dependent on the number of micoorganisms in the
settled sludge.
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Griffiths, J.H.T., & Wisdish, W.J.L., "Diddington Treatment Works: Great Ouse Water Supply
Scheme", Journal of the Institution of Water Engineers. Vol. 21, No. 2, pp. 103-126, March 1967.
Key Words: Water softening, Water purification, Sludge treatment, Design considerations
Design and construction aspects of a water softening clarification facility are reviewed. The
site had good access, nearby delivery mains, and sufficient area. Quality goals included:
softened water with a constant total hardness ratio; and acceptable chloride/carbonate hardness
ratio. Physical and chemical source water quality data are tabulated. Flexible treatment
processes were: cascade aeration; flash mixing; reaction tanks for softening and clarification;
rapid gravity filtration with air scour, low velocity wash, and surface flush provisions;
sludge concentration; and storage handling facilities for ferrous sulfate, alumina, lime, soda
ash, sodium silicate and sulfuric acid. Preliminary chemical house considerations included:
positioning relative to reaction tanks, bunker height and weatherproofing, and lorry bay size.
A Candy centrifugal-balancer-proportional-speed chemical system was utilized. Provisions for
pH correction, activated carbon, and controls, and signalling are discussed. Separate lagoons
process washwater-clarification sludge and softening waste. Architectural and landscaping
details are provided with information on the initial running of the plant.
Haney, P.D. "REPORT ON WASTES FROM MISSOURI AND MISSISSIPPI RIVER WATER TREATMENT PLANTS FOR
MISSOURI RIVER PUBLIC WATER SUPPLIES ASSOCIATION", Report for Missouri River Public Water
Supplies Association, Project Number 6044, December 5, 1972.
.Key Words: Sludge disposal, Water purification, Water treatment, Sludge
Data are presented on the sources, quantities, and characteristics of wastes emanating from
16 water treatment plants located at Omaha, Neb; Council Bluffs, Iowa; St. Joseph, Atchison,
Leavenworth, Kansas; Kansas City, Lexington, Boonville, Jefferson City, and St. Louis City
and County, Missouri. All plants embody multi-stage mixing, sedimentation basins, and rapid-
sand filters plus coagulation with alum or iron salts, disinfection with chlorine, and in
the majority of plants, lime softening. Raw water pumpage is less than 1 percent of river
flow. River sediment removed from and then returned to the river is an extremely small
part of the total sediment load carried by the river. Basin cleaning results in "slug"
discharges which produce minimal adverse effects on quality. Chemical solids from the 12
softening plants are composed principally of calcium carbonate, minor amounts of the
hydroxides of magnesium, iron and aluminum, trace amounts of manganese derived from lime,
river sediment, or potassium permanganate applied for odor reduction. Prechlorination has
a negligible effect on the production of chloride returned to the river. The pH of treatment
plant wastewater is in the 6.5-10.5 range and produces no detectable effect after discharge
into the river. The overall chemical solids on river water quality are virtually nil.
Downstream water treatment plants would not be benefited by the elimination of discharges
from upstream water treatment plants because such discharges are undetectable.
Lathrop, T.R., "Discussion of Disposal of Sludge at Water Purification and Softening Works
of the Mahoning Valley Sanitary District", Journal AWWA, Vol. 25, No. 11, pp. 1530-1533,
November 1933.
Key Words: Ultimate disposal, Continuous sludge removal
A serious problem of handling softening sludge developed with continuous sludge removal, low
river flows, and complaints due to creek discoloration. Softening sludge at Oberlin, Ohio,,
had a specific gravity of 1.13-1.17, 72-85% water content, and density of 70.5-73 pounds/ft .
The Columbus, Ohio plant received complaints after waste discharges were noticed in the
Scioto River. Sludge discharge at Newark, Ohio, created sludge blankets in the river. Sludge
was pumped to an abandoned quarry and borrow'pit in Marion, Ohio. An experimental vacuum filter
reduced moisture content to 50%. The sludge has value equal to agricultural lime for soil
neutralization. In Fostoria, Ohio, sludge is settled in tanks and discharged to low ground.
In Miami, Florida, a 1 to 2 inch covering was excellent for growing grass and vegetables on
account of its quality of holding moisture. The Sandusky, Ohio facility settles and decants
their waste. The major problem is ultimate disposal of solid wastes.
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Levis, C.E., and Smith, W.B., "Lancaster's New Water-Treatment Plant", Journal AWWA. Vol. 64,
Mo. 1, pp. 25-28, January 1972.
Key Words: Water treatment, River intake
Design and construction considerations are enumerated for a new water treatment plant with
sludge handling facilities. A supplementary water source required further development. The
existing plant treated 8 mgd and included: 2 clarifiers; 4 rapid sand filters; a 0.3 mgd
backwash tank; 2 mgd clearwell; 3 high service pumps; and chemical feed equipment. A new
river intake structure was designed to resist ice floe forces, self-scour at the entrance to
minimize sedimentation from the river-bed load, have a manually cleaned. The pump selection
data and clarifier specifications, including glass-fiber reinforced plastic internals for the
high rate solids contact units, are given. An electronic automation system is used. Filter
backwash water is settled in a holding tank with the supernatant pumped to the raw water line.
Sludge from the clarifiers is concentrated in a gravity-type thickener. Sand beds were designed
on the basis of laboratory studies to dewater the sludge.
Lynch, W.O. Baker, C.R., and Haberer, J.H., "Experiences with Microstraining at Ilion",
Journal AWWA. Vol. 57, No. 11, pp. 1422-1430, November 1965.
Key Words: Algae, Microstrainer
The installation of a microstrainer before slow sand filters eliminated filter clogging due to
excessive algal growths in raw water during summer months. Copper sulfate was ineffective in
controlling algae in one impounded surface source. A 7.5 foot microstrainer was installed with
diatomaceous earth filters to pretreat raw water at Ilion. The effects of microstraining were
beneficial in sustaining the output of slow sand filters and lengthening filter runs by removing
microorganisms. Penetration of material into the sand beds increased with microstrainer
pretreatment. It appeared the Schmutzdecke thickness was increased due to the removal of active
zoogleal mass, in a strainer. The mass forms a rough mat that removes fine particles before
entering the bed. More frequent resanding would be required. A filter was evaluated using an
artificial diatomaceous earth Schmutzdecke. The diatomaceous earth coating stopped deep sand
penetration of matter without influencing filter efficiency. The required filter area was
reduced 28% and the net cost of skimming the filters dropped by $2600/year.
McCaughan, F.A.; "Preliminary Engineering Report, Proposed Waste Water Treatment Facilities
For Nueces County Water Control & Improvement District No. 3". Private Communication, October 1970.
Key Words: Alum and lime sludge, Filter washwater, Settling basins, Ultimate disposal
Reagan & McCaughan , Consultant Engineers from Corpus Christi, Texas, have proposed waste treat-
ment facilities to control the pollution caused by sedimentation tank sludge and filter backwash
water at a Nueces County Water Control & Improvement District No. 3 water treatment plant. This
utility provides 1.5 MGD of domestic water for the City of Robstown and the surrounding area.
Lime, alum, and chlorine are used to treat the raw water at this plant. The source water is pumped
from the Nueces River into an earthen canal and then flows into a series of lakes at the treatment
plant site. The wastewater from the coagulation and filter washing processes is presently
discharged to a drainage ditch owned and operated by a Drainage District. The Texas Water Quality
Board has noted objections to this procedure and has advised the District to find a new disposal
technique. The consultants have proposed that the sludge and filter washwater be treated in earth
settling basins. The clarified effluent could then be returned to the raw water lake. Two basins
were provided to allow operation of one and cleaning of the other. The sludge from these basins
would be ultimately disposed of at a suitable site. The settled sludge may have utility as a
fertilizer for grain or cotton crops.
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Milne, J.W., "The Pitsford Treatment Works of the Mid-Water Engineers", Journal of the
Institution of Water Engineers. Vol, 12, No. 1, pp. 83-105, February 1958.
Key Words: Design data, Water softening, Filter washvater, Basin sludge
This paper discussed the treatment facilities for water softening an impounded water supply
and the pumping considerations. The treatment site was chosen for uniformity in slope,
optimization of pumping operation, and placement from sludge treatment units. Design and
construction details are provided for: general arrangement of plant and buildings; raw water
pump house; chemical block; reaction tanks; filters with automatic controllers; filtered
watertank; main pump house and auxiliary engine house; chemical handling; chemical mixing
and feeding; sterilization and stabilization; output control; and washwater and sludge disposal.
Two 93,500 gallon settling tanks are provided for filter washwater. Lime-soda softening
sludge from the concentrator and washwater settling tanks are pumped to a centrifuge. The
centrifuge can handle a 107. sludge at 2500 gallons/hour and produce a 40-50% cake by weight
for landfill. An emergency sludge bed is provided in case of electrical failure to the
centrifuge, conveyor, or shear pin of centrifuge gear unit. Information is provided on
electricity supply and instruments, structural and building details, and operating experience.
Appendices are shown for: composition of main control and instrument panel; motors required
in plant operation; and main contracts awarded.
Flautz, W.H. & Van Kirk, F.N., "Comprehensive Report on Disposition of Sediment and Waste
Backwash Water at the Central and South Water Filtration Plants, City of Chicago, Illinois",
Consoer, Townsend & Associates, Consulting Engineers, 360 E. Grand Ave., Chicago, 111. 60611,
78 pp., February 4, 1970.
Key Words: Quantities and Flows, Disposal of Wastes, Cost and Maintenance
This report presents analyses of quantities and flows of both sediment and waste backwash water
at both Central and South Water Filtration Plants. Various possible alternate solutions for
disposition of the wastes are discussed and analyzed including capital expenditures, operating
costs and maintenance costs. Recommendations based on economic feasibility and good engineering
practices are presented.
Sankey, K.A., ".The Problem of Sludge Disposal at the Arnfield Treatment Plant (Manchester
Corporation Waterworks)", Journal of the Institution of Water Engineers. Vol. 21, No. 4,
pp. 367-378, 1967.
Key Words: Dewatering, Filter pressing, Sludge conditioning
Several sludge dewatering processes are systematically evaluated at the Arnfield Treatment
Plant. Conclusions on optimum sludge concentration and hydraulic capacity, bed covering,
draining and drying cycle,layering effects, mechanical cleaning, and design criteria are
presented for wedge wire sludge filtration. Experimentation with a diatomaceous earth
precoating of a rotary-vacuum filter on a lime conditioned sludge was promising. Preliminary
determinations for filter pressing included the degree of preconditioning, effluent quality,
cycle time, and cake disposal problems for this process. Conditioned sludges were more
easily dewatered than untreated sludges. Hydrated lime was a good conditioner. Slow-stirring
thickening did not enhance dewatering characteristics significantly. Capital and running
costs are tabulated for wedge-wire and rotary-vacuum filtration, filter pressing, and freezing
operations. Filter pressing appeared most economical. A discussion of system parameters
including, cake discharge, automation, downtime, and cloth life is presented for the filter
press. The final design incorporated lime conditioning, provision for slow-stirring
thickeners, and a semi-automatic press. The press supernatant will be recovered.
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Shimmer, J.S. & Davison, A.S., "The Development of Bough Beech As a. Source of Supply (The
East Surrey Water Company)", Journal of the Institution of Water Engineers. Vol. 25, No. 5,
pp. 243-260, July 1971.
Key Words: Water softening, Water purification, Power generation, Distribution pumping
This article reviewed the development of a surface supply capable of yielding 5-6 mgd with
a maximum of 10 mgd. Reservoir and intake site selection was based on water quantity available;
an abstraction formula; water quality; and storage effects. The design philosophy considered:
average/maximum yield relationships; river works; conjunctive use of underground chalk water
and greensand supplies, and surface storage; plant flexibility; distribution needs; phasing
of development; power supply; and controls and instrumentation. The softening-clarification
facility and pumping station was to provide water treatment, power generation, and pumping
to supply. Treatment includes: reaction tanks equipped for softening, clarification, and
recirculation; rapid gravity sand filtration; carbon pressure filtration; treated water
reservoir; pH correction units; chlorination and ammoniation equipment. The generating
plant is to provide flexible operation with 3.3kV at the river works and 250kVA at the mains.
Softening and clarification wastes are separately handled. Sludge is concentrated with
supernatant water returned to the settled water channel. Experiment bays are used to study
methods to dispose concentrated sludge and filter washwater. Appendices summarized physical-
chemical water quality data for the river and reservoir; principal technical data and consultants;
and approximate costs.
Skinner, W.D., "Winfield Wins a New Water Supply", Willing Water. Vol. 16, No. 3, pp. 8-9,
March 1972.
Key Words: Water purification, Lagoons, Surface impoundment, Washwater reclamation
The report outlined a $3.6 million water improvement program including: surface water
Impoundment, water treatment plant, raw and finished water transmission mains, and elevated
storage tanks. Winfield utilized well supplies until improper brine disposal methods from
oil wells caused salt-water intrusion into the aquifers. The development of an impounded
alternative provided the best quality raw water for supply and recreation.' City, Department
of Housing and Urban Development, and Soil Conservation Service costs are tabulated. Raw
water flows by gravity from the reservoir to a conventional clarification plant with solid
contact basins and dual media filters. Pre-sedimentation basins, secondary mixing basins,
clearwell, treated water storage reservoir, washwater reclamation basin, and two sludge
lagoons are included. Flexible treatment operation is planned to cope with taste and odor
problems. Filter washwater is reclaimed in 72,000 gallon basin. Basin sludge is lagooned
or settled in ponds. New distribution lines are tied to existing water mains.
Smith, F.E., "A Study of Sludge Disposal at Water Purification Plants in New England",
Journal NEWWA. Vol. 62, No. 4, pp. 265-274, December 1948.
Key Words: Sludge treatment, Sludge production, Sludge accumulation
This paper discussed sludge production and disposal procedures for iron salt, mud, coarse
suspended solids, color, bacteria, and microscopic organisms. Sludge production and
accumulation is influenced by raw water character, coagulation efficiency, and basin
performance. General basin cleaning procedure is to dewater the tank and pump out the
sludge. Mechanical and daily sludge removal procedures allow continuous operation; eliminate
duplicate units and reduce number and size of basins; increase efficiency; lower operation,
maintenance and initial costs; prevent sludge decomposition in basins; and are more flexible
for design and operation. Sludge disposal methods included release with domestic sewage,
discharge to rivers, stream reservoirs, lakes, or ponds, and lagoons. In discharge to
watercourses, dilution, sludge blanketing, and silting must be considered. Waste transported
to a sewage treatment plant must be examined in relation to sewer system damage, amenability
to existing treatment process, hydraulic and biological plant interferences, and effect
on final plant effluent. Final solids removal is suggested by recovering humic acids and
humates or by landfill. The best method appeared to be mixing with domestic sewage.
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Turre, G.J., "Use of Microstrainer Unit at Denver", Journal AWWA. Vol. 51, No. 3, pp. 354-
357, March 1959.
Key Words: Filtration, llicrostraining
The study described the construction and operation of a microstraining process to remove
microorganisms at a Denver water purification plant. Dimensions of the strainer and steel
tank are given. The drum is three-fifths submerged with a rotational capacity of 0.5-4.0
rpms. The unit, rated at 2.0 mgd, had processed 3.9 mgd of water with.3.0 ppm turbidity.
Construction details and materials are provided. Raw water enters the drum axially and flows
radially through the fabric. Head loss is less than 5-6 inches. A washwater hopper collects
material from drum washing, then drains into the hollow axle of the drum following through
the center of the bearing located on the upstream side of the unit. A row of cleaning jets
on the outside top of the drum flushes solids into the washwater trough. The jet slots are
self cleaning. Wash water requirements are low. Laboratory tests are made on the type and
percentage of organisms removed and turbidity reduction. Percent wash water used, water
strained, washing pressure, and head loss are recorded at the site. A comparison is made
of microstraining and filtration.
Webster, J.A., "Operational and Experimental Experience at Daer Water Treatment Works With
Special Reference to the Use of Activated Silica and the Recovery of Alum from Sludge",
Journal of the Institution of Water Engineers. Vol. 20, No. 3, pp. 167-198, 1966.
Key Words: Sludge treatment, Sludge disposal, Alum recovery
This study describes design and operating criteria developed at the Daer Waterworks to
enhance purification sludge setteability and reduce sludge volume for disposal. Activated
silica is utilized as an aid to aluminum sulfate. An automatic de-sludging system including
a. retention mixing tank, chemical handling and dosing facilities, and additional sedimentation
tanks is described. The sludge volume was assessed through laboratory and plant testing.
Filter pressing of this sludge was not economical. Experimentation focused on slow-stirring
thickening, alum recovery, and freezing of the settled sludge. The recovered alum produced
a good floe in the raw water during laboratory tests. A pilot plant was constructed to
develop design parameters for the thickening, alum recovery, and freezing operation.
Design criteria and operating data are presented for the pilot plant. Refrigeration power
costs and chemical savings costs are tabulated. A small sludge cake must be disposed of
from the freezing process.
Weir, P., "Atlanta's Water Treatment Settled Solids Facility", Paper Presented at the 92hd
Annual Conference of the American Water Works Association, June 6, 1972, Chicago, Illinois.
Key Words: Recycling, Pressure filtration, Settled solids
Settled solids from the Hemphill water treatment plant were discharged to a combined sewer
system. Filter washwater was transported to the Atlantic Steel Company for use as cooling
water. Settled solids from the Chattahoochee plant were discharged to the river. The alum
coagulation sludge could be tolerated at the sewage plant if processes were enlarged and
maintenance problems due to the abrasive nature of the solids were overcome. Sludge was
first recycled to the intake reservoir at the Hemphill plant, but manganese built-up in this
water. The system installed at the Chattachoochee plant included: sludge holding and mixing
tanks; pressure filters; chemical system; feed facilities; and space for loading sludge cake.
The 110 ft3, 44-chamber filters operate at 225 psig with 1813 ft2 of area. A 90 minute cycle
with 100# diatomaceous precoat and 7-10% lime can produce a 40-50% solids cake and a 10 ppm
suspended solids filtrate. Filter washwater is settled, with supernatant recycled. The
facility cost $2.8 million. A pilot filter is described. Similar equipment planned for
Hemphill will cost $10.6 million. Benefits include: recycling washwater and filtrate; easy
handling of dewatered solids; and minimum land requirement.
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Wilcock, E.J., and Sard, B.A., "Design and Operation of the Carmoney Water Treatment Works:
Faughan River Scheme - Londonderry R.D.C.", Journal of the Institution of Water Engineers.
Vol. 18, No. 6, pp. 477-490, October 1964
Kew Words: Water purification, Sludge treatment, Washwater
This study provided preliminary treatment design criteria for a water purification plant. The
ultimate plant capacity of 15 mgd in 3 stages was to supply industrial and domestic consumers
Tabulated raw water quality showed seasonal variations and rapid changes. A flexible treatment
scheme is needed. Proposed treatment included: alum coagulation; pH control using sulfuric acid;
provision for a "weighter"; mechanical flocculation; sedimentation; rapid gravity filtration;
pH conditioning for distribution; and sterilization. The intake works contain screening and
chlorination equipment. Horizontal flow sedimentation basins with mechanical agitation equipment
were chosen. These units are the least sensitive to changes in water quality and flow rates.
Chemical handling facilities are described. Filtration flow rates are 73-87gph/sq.ft.through
graded Leighton Buzzard sand and graded pebbles with a non-ferrous pipe underdrainage system.
Filter washing procedures included air scour, upward water wash, and horizontal surface flush.
Two washwater holding tanks, each of 50,000 gallon capacity, equipped with slow moving paddles
to prevent sedimentation, settled filter washwater. Supernatant washwater is returned to the
plant inlet. Sludge from the washwater holding tanks and sedimentation basins is sent to
lagoons. Operational experience, remedial measures, and plant cost details are provided.
Young, E.F., "Water Treatment Plant Sludge Disposal Practices in the United Kingdom",
Journal AWWA. Vol. 60, No. 6, pp. 717-732, June 1968.
Key Words: Sludge treatment
This review reported on specific sludge treatment technological applications at English Water
utilities. Physical and chemical character of coagulation and softening waste was discussed.
Two important initial parameters are sludge volume and concentration. A figure showed suc-
cessive alternative stages in sludge disposal. Drainage time for hydroxide sludge was related
to the square of the applied sludge depth. The Water Research Association claimed: softening
sludge dewatering characteristics can be controlled by the method used; shallow covered
lagoons are needed for hydroxide sludge; and polymers with molecular weights of 1,000,000 or
more added to settled sludge are effective. The Stocks and Fishmoor plants use slow stirring
thickeners and a.freezing tank. The Broughton Softening Works used a pellet seed reactor.
The Manchester Corporation Arnfield plant holds, thickens, and filter presses basin sludge; and
microstrains and rapid gravity filters backwash water. Both supernatants return to the plant
inlet. The Daer Water Board has sedimentation tank sludge and settled washwater sludge that is
acifified and thickened to reclaim alum. Remaining sludge is frozen. Other facilities listed
thicken,lagoon , and centrifuge wastes. Design should be flexible and follow laboratory or
pilot testing.
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WASTE TREATMENT IN NEW WATER TREATMENT PLANTS
Cedroni, E., "Considerations in Large Water Plant Design", Journal AWWA. Vol. 64, No. 5,
pp. 299-303, May 1972.
Key Words: Water treatment, Central control panel, Drying beds
Design criteria are given for a water treatment plant utilizing a functional central control
panel and providing waste disposal. Construction details are given for the submerged timber
intake crib. Initial problems and solutions in constructing the intake shaft and surveying
the raw-water tunnel are described. Details are provided for the low-lift plant, high-lift
plant, chemical handling and storage facilities, settling tanks, and filtration plant. Sanitary
wastes are disposed in septic tanks. Filter washwater is recirculated. Sludge from the
settling basins is clarified with the supernatant overflow recirculated. The condensed sludge
is discharged to drying beds. A central control panel is explained. The only information on
the board is that needed by the operator to make decisions within the plant.
DeFillippi, J.A., "Designing Filtration Plant Waste-Disposal Systems", Journal AWWA. Vol. 64,
No. S, pp. 185-187, March 1972.
Key Words: Sludge treatment, Basic data collections, Design process, Subsystems
Regulatory agencies will not accept shock or concentrated loads to water-courses. Increasing
land costs in urban areas make lagooning expensive. Recycle systems may be economical. This
study showed long-term lagooning as treatment for backwash and clarifier wastes can be
eliminated. New design requires: definition of sludge dewatering characteristics; choice of
design processes, subsystems, and final layout. Suspended solids concentrations of waste
volumes are of interest. Correlations of turbidity and suspended solids and sampling -
laboratory programs are suggested. The plant process, operation, raw-water flow-quality data,
and physical layout must be considered before programs are detailed. Treatment alternatives
include coagulation-settling of backwash and clarifier sludge thickened; or mechanical dewatering
of clarifier sludge separately with special surge tank for washwater. Mechanical dewatering
processes for alum-lime sludge are centrifugation; vacuum filtration, and pressure filtration.
Following laboratory tests on thickened-unthickened sludge with and without chemical pretreatment,
pilot-scale tests should be initiated. Basic data must be available for design development.
John, Robert L., "Filter Plant Includes Waste Treatment", Water & Sewage Wastes. Vol. 118,
No. 4, pp. 96-98, April 1971.
Key Words: Waste treatment, Thickening, Alum sludge
This paper describes the instrumentation, chemical handling, equipment, and plant facilities
of a water filtration plant designed to treat its filter wash water and settling basin sludge.
The Clean Streams Law of Pennsylvania requires treatment of purification plant wastes. The
filter wash water facilities include a wash water sump and pumps to return the wash water to
the raw water supply entering the plant. The wash water provides artificial turbidity which
is believed to enhance coagulation and flocculation. Provisions are available to partially
dewater this waste in a clarifier-thickener. The alum sludge from the settling basins is
discharged to a sump before entering the thickener. Supernatant from the thickener contains
less than 100 mg/1 suspended solids and is discharged to a stream. A 4 to 5 percent solids
sludge is pumped from the thickener to a sump. The alum sludge is pumped into tank trucks
for hauling to a pit-lagoon offsite disposal area. Various industrial wastes are disposed
there. A tabulation is made of the equipment suppliers, and construction costs for the water
treatment facility.
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Proudfit, D.P., "Selection of Disposal Methods for Water Treatment Plant Wastes", Journal
AWWA. Vol. 60, No. 6, pp. 674-680, June 1968.
Key Words: Recalcining, Chemical recovery
A study of sludge treatment facilities at three Colorado Springs plants needing treatment
systems. Plant 1 treated raw water of 8 turbidity units and 100 ppm TDS with alum, soda ash,
and chlorine. A wastewater recovery basin was built to retain sedimentation sludge and filter
washwater. Plant 2 treating a less turbid water, constructed recovery basins. Plant 3
recaptured supernatant from sludge and backwash water settling. Solids were processed on
drying beds for landfill. St. Paul decided on recalcining lime and recovering filter wash-
water at their softening plant. Mg(OH)2 was separated from CaC03 by carbonation and centrifugal
classification. Waste solids are lagooned. Ihe C02 from recalcining is used for chemical
stabilization of the finished water and sludge recarbonation. Washwater is recycled to the
sedimentation basins. Expected yearly results were: 9800 tons 92% CaO; 330 tons excess CaO
for sale; 9950 tons C02; 170 million gallons washwater recovered; sludge volume for disposal
reduced by 83%; and reduced load to sewage treatment. In Minneapolis the waste plan included:
alum regeneration; lime recalcining; C02 recovery; magnesium recovery; and hydrochloric acid
production. Each handling problem is unique.
*****
WATER CONDITIONING PRACTICES
Evans, G.R., "Review of Experiences with Microstrainer Installations", Journal AWWA. Vol. 49,
No. 5, pp. 541-549, May 1957.
Key Words: Filtration, Microstrainer
A report on the utility of microstraining for municipal and industrial water clarification.
Advantages included: low initial outlay; small space requirements; low head loss; automatic
operation; and low maintenance costs. Equipment and construction details, and operation and
maintenance costs are provided. Equipment and construction details are provided for an
installation. Operation and maintenance costs are estimated at $l-1.50/million gallons,
including power and backwash water charges. Four standard units are available. Efficiency
depends on the formation of a thin mat of intercepted solids on the inner fabric surface.
The strainer does not appreciably reduce true collodial matter or color. Filter media apertures
are 60, 35, and 23 .u. A formula to select and size filtrability index, flow volume, speed drum
and fabric area, and loss of head across fabric. Applications include: sole filtration
process; pretreatment before filtration; filtration following flocculation and sedimentation;
reduction of .suspended matter in secondary sewage and industrial effluents; and prevention of
waterborne parasitic disease.
Harris, R.H., "Use and Control of Polyelectrolyte Filter Aids in High Rate Filters", Paper
Presented at 91st Annual Conference, American Water Works Association, Denver, Colorado. June
13-18, 1971.
Key Words: Turbidity, Filter aid
The application of filter aids in three Southeastern water treatment plants and a technique for
operating and maintaining aid dosage levels. Filter aids have reduced primary coagulant dosages
and produced longer filter runs and high quality filtrate. Headless build-up and backwashing
problems occur when aids are overdosed. A schematic of a filter aid feed system for polyelectrolytes
is presented. A turbidity monitoring system utilizing a 90° scatter nephelometer type turbidi-
meter is detailed. Optimum^filter performance is obtained in dual-media filters, with a coarse
anthracite top and sand bottom, when 90 to 95 percent of the turbidity is removed in the anthracite
portion and anthracite-sand interface turbidities are cyclically monitored. Data on raw water
character, treatment conditions, and test results are enumerated for the three treatment facilities
using this system.
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Lees, Ronald D., "The Role of Polyelectrolytes in Water and Waste Treatment", Presented to
Che Man!tola Department of Health and Social Services, Winnipeg, Manitoba, Canada, March 15, 1971.
Key Words: Water treatment, Polyelectrolytes
This paper describes the utility and effectiveness of polyelectrolytes for filtration,
sedimentation, and sludge dewatering applications. Ionic polymers attract electrically
charged colloids, forming bridges between the suspended solids particles. This bridging
action enhances settling and dewatering. The most ideal polymers are easy to use, heavily
weighted, with excellent pH stability, wide dosage levels, slightly affected by sharp system
character changes, and with the proper type and amount of functionality. Polyelectrolytes aid
filtration by providing longer filter runs with cleaner filtrates. Polymers improve sedimentation
by increasing tank capacities, producing cleaner effluents, and providing thickening and
compaction of sludge blankets. Polymers have demonstrated usefulness in dehydrating settled
sludge, filter cake, and centrifugation residues. Polymers prove effective as settling aids
for the coagulation of phosphates from w.astewater. The application of polymers as conditioning
agents for flotation and vacuum filtration processes is discussed. On-site in-depth testing
is required.before the full-scale application of polymers at a facility.
Sexsmith, D.R., Savinelli, E.A. & Beecher, J.S., "The Use of Polymers for Water Treatment",
Industrial Water Engineering;. Vol. 6, No. 12, pp. 18-23, December 1969.
Key Words: Scaling, Flocculation, Dispersion, Polymers
This report reviewed the utility of polymers for flocculation, dispersion, and scale control.
The four polymer types are natural, modified natural, vinyl, and condensation. Universally
applicable polymers do not exist. The most important properties are molecular weight and
charge. Molecular weight is related to bridging and adsorbing action. Functional groups
influence the electrical charge to neutralize surface charges of collodial particles. An
overdose of a highly charged polymer could create electrical imbalance and act as a dispersant.
A dispersant prevents particle agglomeration, bridging, and settling. Some polymer combinations
reduce boiler tube or cooling tower incrustations and remove existing scales. Highly concen-
trated carboxyl groups and combinations of polymeric and complexing agents are best for scale
control. Three case histories are discussed. A polymer-polyelectrolyte combination reduced
deposit thickness in boiler tubes plugged with phosphate, lignin organic, catalyzed sulfite,
and neutralizing amine scale. Cleaning and fuel consumption costs were reduced. A cationic
polymer reduced a silt, iron oxide, and microbial slime scale in heat exchangers at an oil
refinery. A combined polymer-sequestering agent reduced cooling tower scale at a foundry
operation.
Williams, J.W., "Effect of Water Conditioning on Wastewater Quality", Journal AWHA. Vol. 60,
No. 12, pp. 1329-1335, December 1968.
Key Words: Ion exchange, Sodium zeolite
This paper discussed chemical precipitation and ion-exchange softening of water. Types of
hardness are described. Softening costs at filtration plants are as low as $0.03/1000 gal/
100 ppm hardness removed. Unit costs are higher for lime-soda when significant non-carbonate
hardness is present. Savings of $11.7c/1000 gal/100 ppm hardness removed are estimated for
soap, detergents, lyes, bleaches, shampoos, hand lotions, coffee, tea, fuel, washable clothing,'
linens, towels, and plumbing repairs. Soft water is more corrosive than hard water. Chemical
precipitation softening equations are prepared. Ion exchange is preferable when: substantial
non-carbonate hardness exists; waters contain less'than 100 ppm hardness; low effluent hardness
is required; sludge disposal facilities are not available; and small water volumes need
softening. Regeneration of resins is by backwashing, ion replacement, and rinsing. Waste
products are excess regenerant and hardness ions. Softening capacity is usually expressed
as grains hardness as CaC03 removed/ft3 resin. Most economic salt usage is 0.3-0.5 Ibs/
1000 grains hardness removed. Wastewater reclamation may be feasible by membrane processes
on waters of 1000 IDS. Other disposal methods are discharge to ocean outfalls, sewers, or
deep well injection.
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WATER TREATMENT PLANT WASTES
Review Articles
AWWA Book, "Water Quality and Treatment", McGraw-Hill, New York, N.Y. (1971), pp. 625-645.
Key Words: Sludge disposal, Residues
Chapter on the nature of water treatment plant residues, disposal techniques, by-product recovery,
and aesthetic and legal aspects of the waste disposal problem. Residue sources include: aluminum
and iron oxides, sands, silts, and organic matter from chemical coagulation processes; CaCO^*
Kg(OH)2, and lime from softening by precipitation; filter backwash water; iron-manganese oxides;
and spent activated carbon and ion-exchange regeneration brines. Chemical coagulation and
filter backwash wastes have traditionally been discharged to watercourses, storm and sanitary
sewers, sludge beds, and impounding basins or lagoons. Disposal methods for softening wastes
by precipitation are similar. Ion exchange brines have been injected into the ground, discharged
to watercourses, or evaporated. Reactions are given for lime recalcining,.'iron and alum recovery.
Sludge discharged to watercourses may create sludge blankets which inhibit natural biologic
activity, increase turbidity and stream color, and exceed state and federal water quality
standards. Additional research is suggested.
Faber, H.A. & Nardozzi, A.D., "Disposal of Water Works Wastes", Paper Presented at Iowa Section
AWWA Meeting, Des Moines, Iowa, (1971), 20 pages, (unpublished).
Key Words: Sludge treatment, Sludge disposal, Treatment alternatives, Research needs
Review of the development of treatment alternatives to process lime-soda and alum sludge and
filter washwater. Waste discharge regulations for Iowa and the nation compared. Processes
discussed included: settling or lagooning; drying beds; freezing; lime recovery; alum recovery,
filter pressing, and chemical coagulation. Evaluation of magnesium carbonate as a. recycled
coagulant and the effectiveness of polyelectrolytes as primary coagulants, coagulant aids,
and sludge conditioning agents. Research needs suggested were development of uniform reports
on sampling, analysis, and waste categorization; investigation and application of new or
modified physical and chemical liquid-solids separation processes; and more detailed investigation
of by-product recovery technology. Demonstration is required on the utility of polymers, filter
washwater recycling; and solid waste recovery for reuse or marketing.
Faber, H.A. & Nardozzi, A.D., "Water-Treatment-Plant Waste DisposalAction Now!" Journal
AWWA. Vol. 64, No. 10, Part 1, pp. 674-680, October 1972.
Key Words: Sludge treatment, Sludge production, Unit processes
Discussion of specific sludge and filter washwater wastes from water purification and softening
facilities. Sludge production and handling were related to: sludge types; suspended and
dissolved solids removal chemistry; raw water quality; qualitative and quantitative physical-
chemical constituents; treatment plant efficiency; and sludge withdrawal methods. Potential
correlations of raw and treated water parameters to sludge production are given. Other
considerations include: problems in pumping and gravity flow; unit processes or process
sequences under development to dewater or recover by-products. Two phases of work are
described to establish uniform sampling, analysis, and categorization techniques for all
types of water treatment plant wastes and evaluate polyelectrolytes for use as primary
coagulants, coagulant aids, and sludge conditioning agents. Research needs, and recommendations
are enumerated.
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Faber, H.A. & Nardozzi, A.D., "Information Resource: Water Pollution Control in the Water
Utility Industry", Report 12120 EUR for EPA, 169 pp., Nov. 1971, (For sale by Supt. of
Documents, Washington, D.C.).
Key Words: Sludge disposal, Sludge treatment, Information clearing-house, Information resource
This report describes the accomplishments of a program conducted to organize, coordinate, and
disseminate information on new or modified sludge treatment technology for water treatment
plant wastes. The reliable control of these potential pollutants is of increasing importance
with the enactment and enforcement of more stringent pollution control legislation. The report
contains information on research, engineering, plant operation, and regulatory aspects of the
problem. A Project Advisory Committee provided recommendations for development of information
resources, and assisted the Research Foundation in structuring an information clearinghouse.
The report describes current research activities and new approaches for characterizing and
reducing water treatment plant waste volumes. A program was initiated to evaluate the
applicability of polymers as primary coagulants, coagulant aids, and sludge conditioning
agents. A Sub-Committee was established to prepare uniform sampling, analysis and categorization
techniques for water utility sludges. Each program is in progress. Surveys were distributed
to water utilities and regulatory agencies to provide information on sludge treatment methods
and requirements. The AWWA Research Foundation plans the continuation and expansion of this
centralized information resource program.
Hudson, H.E., "How Serious is the Problem?", Proceedings Tenth Sanitary Engineering Conference,
Waste Disposal from Water and Wastewater Treatment Processes, University of Illinois, Urbana,
Feb. 6-7, 1968.
Key Words: Recycling, Water sludge
Industrial and water consumption totals 150 and 360 tons/capita/year. Over 60 million tons/
year of water and wastewater sludges (dry basis) are generated. Sludge loads from water treat-
ment plants are 15 pounds/capita/year. The handling of waste quantities must be done to create
equilibrium conditions with the environment. Detroit, Michigan recycles washwater and benefits
by improved settling and filtration. Seasonally cleaned basins require separate treatment or
holding facilities while continuous sludge removal units could discharge to sewers. Zeolite
softening and electrodialysis brine streams have been diluted by discharge to streams. Calcining
and reuse is suggested for chemical precipitation softening waste, with magnesium being separated
or recovered. Clarification sludges can be vacuum filtered with lime conditioning. Alum
recovery is practiced in Japan. Cationic polyelectrolytes may become effective as primary
coagulants. Water treatment plant sludges would add a 10% solids loading to sewage treatment
plants. The author concludes economic methods must be developed to recycle wastes.
Singley, J.E. & Black, A.P., "Water Quality and Treatment: Past, Present, and Future",
Journal AWWA, Vol. 64, No. 1, pp. 6-10, January 1972.
Key Words: Water treatment, Process
This study reviewed past and present water treatment history and cited potential processes
and control parameter refinements requiring further investigation and application. Water
treatment design has been traditionally conservative. Some utilities have adopted: polymers
for use as primary coagulants and coagulant aids; automatic monitoring and process control;
and have instituted individual research programs. The time lag between process development
and plant adaption must be decreased. Research considerations included: process optimization;
development of new control methods and caogulants; place and extent of mixing; increased
automation; development of new filtration media; the effect of tract minerals and organics;
improving disinfection; and sludge disposal. The utility of recovering and recycling MgC03
at purification facilities is discussed. A 50 gpm pilot plant is evaluating this recycled
coagulant for effectiveness in reducing color and turbidity at Montgomery, Alabama.
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WATER TREATMENT PLANT WASTES
Committee Reports
AWWA Committee Report, "Purification Plant Waste Disposal", Journal AWWA. Vol. 45,
No. 11, pp. 1225-1237, November 1953;
Key Words: Sludge disposal, Brine disposal, Filter plant wastes
Final committee report consisting of the following separate published reports: (1) "Lime and
Lime-Soda Sludge Disposal," December 1957 Journal, page 1211; (2) "Brine Disposal From Sodium
Zeolite Softeners," December 1947 Journa'l, page 1215; (3) "Disposal of Wash Water From
Purification Plants," December 1947 Journal, page 1219; (4) "Lime and Lime-Soda Sludge Disposal",
September 1949 Journal, page 819; (5) "Brine Disposal From Cation-Exchange Softeners", November
1949 Journal, page 829; (6) "Disposal of Wastes From Filter Plants and Coagulation Basins,"
1953 Journal, page 1226. It was realized that each treatment plant has a problem that is
probably unique to itself. Therefore, the desire of the members of this committee has been to
present a report containing a general coverage of the subject, with sufficient references to
guide anyone endeavoring to solve a specific problem to information applicable to that problem.
AWWA Committee Report, "Disposal of Water-Treatment-Plant Wastes", Journal AWWA. Vol. 64,
No. 12, pp. 814-820, December 1972.
Key Words: Sludge treatment, Waste volume minimization
This study reviewed reclamation, handling, and disposal procedures for water treatment wastes
and recommended areas requiring further research. Waste discharges to watercourses will be
limited by strict pollution control legislation. Waste disposal processes should be incorporated
into new treatment plant designs, for minimization of waste volumes, water reuse, and by-product
recovery. Lime and alum recovery processes are described. Filter backwash recycling is
discussed. Future research recommendations include: developing standard methods for sampling,
analyzing, and cateogrizing wastes; waste quality minimization procedures; chemical and water
recovery; waste quantity and character improvement through polymer utilization; and new
disposal techniques.
Illinois Section Water Resources Quality Control Committee, "Water Treatment Plant Wastes",
AWWA Annual Conference, March 19, 1970.(Unpublished.)
Key Words: Questionnaire, Waste characteristics, Filter plant wastes
Existing waste disposal methods for basin sludge removal and disposal and filter backwash
disposal were evaluated through analysis of a questionnaire distributed to surface water and
ground water treatment plants throughout Illinois. Data for types and quantities of wastes
were compiled from six to nine month operating records and analysis of grab samples. Basin
sludges varied in chemical, organic, and inorganic composition in relation to the processes
employed as well as source of process water. Lime softening systems produced basin sludges.
rich in calcium carbonate and hydroxides of magnesium and aluminum. No generalizations could
be drawn from any of the data with respect to any plant processes. Excluding the amount
of lime required to remove hardness, all other attempts at correlations proved futile due to
poor sampling techniques. Examinations of filter backwash water indicated solids release
patterns exist. A relationship between suspended and settleable solids released and time for
such release could lead to the optimization of backwash rates and times. The limited filter
backwash data strengthened the need for more efficient and uniform techniques as well as
creating interest in the proposition of higher solids loading per unit area of filter.
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WATER TREATMENT PLANT WASTES
Characteristics of Wastes
Calkins, R.J., "Characterization of Chemical Sludges", Paper Presented at Annual Conference
of AWWA, June 7, 1972, Chicago, Illinois. (Unpublished.)
Key Words: Filtration, Sludge characte.
This paper relates sludge characteristics to the chemical process scheme and raw water quality.
The methodology used is described. Twenty five water purification, softening, and combined
sludges were studied in relation to settled solids concentration, filtration rate, and cake
solids. General results included: iron coagulants provided more compact sludge than aluminum
coagulants,with a Catfloc sludge the heaviest; increasing magnesium content adversely affects
settleability and sludge -compaction for iron and aluminum coagulant sludges; sludges from turbid
water attain higher settled solids concentrations than sludges from low turbidity raw waters;
and backwash solids settle to one-half the concentration as from the preceding settling unit.
Specific resistance and filter loading are determined. Combined softening - purification
sludges filter more rapidly than do pure coagulants. Sludge with specific resistance <10 x 10
sec2/g filter well. Filter backwash sludges exhibited poor filtering quality. Sludge can be
characterized by volumetric techniques by evaluating settled solids in a graduated cylinder;
Cosens, K.W., "Water and Wastewater Treatment Plant Sludges", Presented at West Virginia
Joint Section Meeting, American Water Works Association and Water Pollution Control Association,
Wheeling, West Virginia, April 6, 1972. (Unpublished.)
Key Words: Sludge treatment, Disposal methods
Data are given for particle size and settling velocities of alum and iron floes; sand,, salt,. ,
and clay floes; and softening wastes. Softening of surface water produces 3.5 Ibs. dry solids/
pound of hardness removed as CaCO$. Sludge treatment or disposal methods are: dilution, lagoons,
sand drying beds", vacuum filtration, freezing, filter pressing, centrifugation, land disposal,
recovery, and discharge to sanitary-sewers. The Little Falls plant plans to thicken sedimen-
tation coagulation sludge and settle washwater. Concentrated sludge is held, centrifuged,
conditioned by lime and polymer, and presses with the cake used for landfill. Presses process
50 tons/8 hours. Portsmouth, Ohio, plans vertical basket centrifugation of alum sludge and
land disposal. Columbus, Ohio, proposes recovering magnesium and lime from softening sludge
in a 10 gpm pilot facility. Fremont, Ohio, plans centrifugation of softening sludge and land
disposal in quarries or farm fields. St. Paul recalcines their lime sludge.
Gates, C.D. & McDermott, R.F., "Characterization and Conditioning of Water Treatment Plant
Sludge", Journal AWWA. Vol. 60, No. 3, pp. 331-344, March 1968.
Key Words: Sludge treatment, Alum sludge
The purposes of this study were to develop methods to measure alum sludge character and to
determine the relationship between dosage and specific resistance as a valid measure of poly-
electrolyte effectiveness on dewatering. Important parameters were: total solids content;
settleability; and filterability. Drain-effluent and in-place basin samples were tested. There
was zone settling until compression occurred. The initial settling rate of sludge-liquid inter-
face was related to the total solids concentration. The Buchner funnel method was modified to
permit a valid comparison of polyelectrolyte effect on filterability. Specific resistance
values were recorded. Sludge greater than 1% in solids exhibited non-Newtonian flow character.
Sampling, collection, and testing methods to evaluate 4 polyelectrolytes are described.
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RusseLmann, H.B., "Characteristics of Water Treatment Plant Wastes", Proceedings Tenth Sanitary
Engineering Conference, Waste Disposal from Water and Wastewater Treatment Processes, University
of Illinois, Urbana, Feb. 6-7, 1968, pp. 10-20.
Key Words: Waste identification, Water treatment plant wastes
Water treatment plant wastes produce fewer problems than wastewaters from municipal sewage
and industrial facilities because they are: less in volume; low in magnitude of pollution; and
not a public health hazard. These are pollutants because; they contain damaging constituents;
pollution control is more demanding; new techniques generate new problems; and stream use is
competitive. Waste discharges create unsightly deposits, odors, hinder biological activity,
deplete oxygen, interfere with photosynthetic processes, and are toxic. Raw waters contain
organic, inorganic, and microorganism materials. Various alum and iron salts, chlorine,
polyelectrolytes, lime, soda ash, and activated carbon are added. Coagulation sludge and
filter washwater parameters including BOD5, COD, pH, total solids, volatile solids, total
suspended solids, and volatile suspended solids are tabulated. Backwash water is discharged
to storm drain and streams, lagooned, and recycled. The objective with ion-exchange brines
is to minimize discharge concentrations and variations. Wastes from reservoir cleaning;
deplete oxygen rapidly; reduce temperature sharply; release high turbidity and color; and
create sludge. Waste treatment must be considered in future designs.
******
WATER TREATMENT PLANT WASTES
Treatment of Filter Washwater
Hall, H.R., "Disposal of Washwater from Purification Plants", Journal AWWA. Vol. 39, No. 12,
pp. 1219-1223, December 1967.
Key Words: Sludge treatment, Waste characterization, Disposal methods
This report outlined waste character, quantity, effects, disposal methods, and legal difficulties
considerations for water treatment sludges. Washwater turbidities of 2000 ppm have declined
to 50-100 ppm during backwash. A one hour detention period can lower turbidity to 40-50 ppm.
?re-chlorinated supernatant is practically free of coliform organisms. Methods to effectively
determine BOD are not included in Standard Methods. Each plant individually must determine
waste quantity based on sludge character. Wastes contain silt and chemicals. Discharge to
streams can cause discoloration, but public health is not jeopardized. Odors can emanate
from stored sludge. Disposal methods include: discharge of washwater and sludge wastes to
streams without treatment; lagooning of washwater and sludge with supernatant discharged to
stream or returned to the plant inlet; washwater and sludge to sewers; and pumping to a
reservoir. Experiments were conducted on settling filter washwater and basin sludge. The
City of Laurel enjoined suit on an upstream facility discharging was.te to river, charging
quality degradation due to sludge disposal. The need for further definition of pollution
effects, health hazard, and pre-chlorination of washwater to decrease bacterial content was
established.
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Hirsch, A.A., "Backwash Investigation and a Proposed Simple Uniformity Control", Journal AWWA,
Vol. 60, No. 5, pp.570-585, May 1968.
Key Words: Temporal distribution, Backwash
This study investigated backwash characteristics, washing process dynamics, effect of bed
structure, and theoretical considerations for filter design. Suspended solids concentrations
of backwash samples were taken at the troughside bottom, intertrough median, a corner, and
the sewer. Sampling intervals were 1/15 seconds. Testing at Shreveport, Louisiana, showed
vashwater streaks toward trough edges. Uniform washwater removals over the entire filter
surface were achieved utilizing nozzles 6 inches on center above the filter bed. Short-
circuiting in backwash must be avoided. A measured velocity profile showed that washwater
is wasted, operation and maintenance problems begin, and uneven filtering occurred following
non-uniform washing. The area under backwash curves of suspended solids concentrations versus
time gives sediment removed. Peak backwash concentrations decay logarithmically. Formulations
are presented for determining decay and washing efficiency. Inversely graded beds yielded
broader backwash curves than traditional filters. The report showed: most thorough washing
occurred at the bottom of the vertical- walls of trough; draw-off members can be classified
according to simple geometric counterparts; and filter beds wash unevenly due to the directional
influence of the washwater troughs.
Pallo, P.E., Schwartz, B.J. & Wang, L.K., "Recycling and Reuse of Filter Backwash Water
Containing Alum Sludge", Water & Sewage Works. Vol. 119, No. 5, pp. 123-125, May 1972.
Key Words: Recycling, Filter washwater
The purpose of this article was to investigate the feasibility of directly recycling filter
vashwater together with alum sludge to the flash mixer of a conventional water treatment plant
and to study the possible effect of recycle on effluent quality and sedimentation operation.
Composite samples of filter backwash were jar tested. Physical and chemical parameters were
determined by Standard Methods and listed. A holding basin was used to equalize the filter
backwash water before the washwater with alum sludge was returned to the flash mixer. Data
Showed: backwash water is an effective coagulant' aid up to 40% recycle in reducing color and
turbidity; a pH drop caused by recycling aided alum coagulation; a 2% recycle reduced alum
dosage requirements from 1.2 to 1.0 grains/ gallon while maintaining efficiency; and recycling
yielded a denser and smaller floe settling at a faster rate. Based in Imhoff cones, 95% of
the sludge was precipitated in 20 minutes by recycling compared to 35 minutes without recycling.
Recycling backwash avoids stream pollution and reclaims water for reuse.
Van Reuth, A.G., "Treatment and Disposal of Sedimentation Tank Sludge and Sand Filter Backwash
Water, Van Bibber Water Treatment Plant, Edgewood Arsenal, Maryland", Personal Communications,
Dec. 1970.
Key Words: Alum sludge, Centrifugation, Dewatering processes
Several treatment processes were evaluated for concentrating the predominantly aluminum hydroxide
sludge at this purification plant with a design capacity of 4.0 mgd. Laboratory tests were
conducted on potential dewatering methods including vacuum filtration, sand filtration, evaporation
and decanting (lagooning), freezing, chemical treatment, and Centrifugation. Evaporative lagooning
with decantation and Centrifugation with chemical treatment were found to warrant further
investigation in this application due to their practicality and efficiency. Field demonstration
tests on waste conditioned with synthetic organic polymers were made using a Dorr-Oliver Merco
Bowl Long Bowl Centrifuge. These tests showed that Centrifugation was the most economical
treatment process for the handling of the sedimentation tank sludge and sand filter backwash
water. The recommendations from the study have been adopted and now constitute the basis for
design and construction of new facilities which are scheduled for early completion at the Van
Bibber Plant. The construction costs are estimated at $180,000 and annual operating and
maintenance costs are estimated at $29,000. Van Reuth and Weidner, Inc. will provide the
engineering services.
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Westerhoff, G.P., "Action Now in Filter Plant Washwater Treatment", Paper Presented at Spring
fleeting of the New York Section of the American Water Works Association, Syracuse. New York.
April 6, 1972.
Key Words: Sludge treatment, Alum recovery, Waste reduction
This report outlines a two phase program to evaluate alum coagulation sludge and filter wash-
water treatment processes. Alum sludge is difficult to dewater. Sturgeon Point treatment
includes: aeration, chemical addition, mixing, flocculation, and sedimentation, filtration,
pH adjustment, flouridation, and chlorination. Plant scale design data must be developed
for wastes. Alum sludge solids, consisting of A1(OH)3, organic and amorphous materials, vary
from 50-200 Ibs/million gallons of water produced. A composite backwash analysis showed 65
Ibs solids/million gallons filtered water. Basic proposed facilities include: sludge and
washwater holding tanks, thickener-clarifier, waste lagoons, centrifuge, filter press, half-
scale alum recovery plant, and backwash recycling equipment. Alum recovery is expected to
reduce waste solids to one-sixth their original volume and produce a reuseable alum. The
recovery process includes: thickening of sludge, acidulation with H2S04, thickening-separation,
filter pressing, feed systems, control equipment, recovered alum storage, and recycling, all
on batch or continuous bases. Preliminary work showed no iron or color build-up in relamation.
The study programs aim to: identify physical-chemical waste character; evaluate liquid-solids
separation with and without aids; determine feasibility of alum recovery; evaluate recovered
alum effects on plant operation; and reduce backwash water flow quantities..
WATER TREATMENT PLANT WASTES
Treatment of Sludges
Chemical Recovery Processes
Roberts, J.M. & Roddy, C.P., "Recovery and Reuse of Alum at Tampa", Journal AWWA. Vol. 52,
No. 7, pp. 857-866, July 1960.
Key Words: Sludge treatment, Alum reclamation
Alum reclamation proved economically and technically feasible at Tampa, based on laboratory
tests. The facility employed alum coagulation of water containing varying organic color and
mineral content. One commercial ton of alum applied equals 525 pounds of A1(OH)3 sludge, 1.9
pounds of H2S04 is needed to react with 1.0 pound of A1(OH>3. Successful laboratory work
led to pilot plant studies. Two pilot plants were built to evaluate maximum thickening
conditions. A third plant was constructed to treat raw water with reclaimed alum. The
resulting floe was collected, thickened, and reacted with concentrated I^SO^ to produce
Alum, recycled 8-10 times, showed no interference with acid-insoluble material or any change
in chemical or bacteriologic water quality. A plant scale study of commercial versus reclaimed
alum was made. Proposed facilities included: a 20 rogd conventional settling basin, equipped
with sludge collectors, to concentrate sludge; a thickening basin; and sludge reaction tank
where H£S04 is added and mixed. Reclaimed alum will be recycled to the raw water.
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Black, A.P., Shuey, B.S. & Fleming, P.J., "Recovery of Calcium amd Magnesium Values from
Lime-Soda Softening Sludges", Paper Presented at Ninety-First Annual Conference American
Water Works Association, Denver Convention Complex, June 13-18, 1971.
Key Words: Water treatment, Calcining, Magnesium carbonate
The carbonation of softening sludges containing magnesium hydroxide produces a selective
dissolution of the magnesium precipitate to its carbonate form. A tabulation of liquid sludge
volumes and calcium carbonate, carbon dioxide, and magnesium hydrxide production is presented
for Dayton. Carbon dioxide from lime calcination is utilized to carbonate sludge from settling
basins. The mixture is thickened and the calcium carbonate precipitate withdrawn for centri-
fugation. Lime recovery reduces chemical costs, waste disposal problems, and produces excess
lime for sale and carbon dioxide for carbonation. A pilot plant was constructed to produce
magnesium carbonate on a batch basis. The process includes carbonation of softening sludge,
settling or filtration of calcium carbonate solids, and heating and aeration of the magnesium
carbonate solution. The major reactions, are listed. The hydrated carbonate precipitate is
vacuum filtered, dried, and bagged. Filtrate is recycled to storage tanks for subsequent
recovery. Data are provided from the pilot operation. The process is adaptable to waters
with high clay turbidities with the addition of a flotation step following recarbonation.
Potential magnesium carbonate production capacities and estimated revenues are calculated
for 20 cities.
Fischer, A.J., "Discussion on Pontiac Recalcining Plant", Journal AWWA, Vol. 40, No. 4,
pp. 465-466, April 1948.
Key Words: Calcium carbonate, Recalcining
The recalcining of lime has been practiced in the heavy chemical and paper pulp industries
for several years. In the water treatment industry, lime reclamation has been economical
when burning 25 tons CaO/day in conventional rotary kilns. The Fluo Solids Calciner recaicines
dry calcium carbonate sludge to an air fluid suspension. Fluidizad suspension burning has been
used in the pertoleum industry for roasting ores. Sludge from the precipites is cehtrifuged,
conditioned with soda ash and dried sludge, passed to Raymond flash drier, and burned in the
Fluo kiln. The kiln temperature is 1750°F with the CaO pellets discharged at a temperature
of 300°F. The advantages of this system are compactness, low installation cost, low operation
and maintenance costs, and dust free operation.
Gordon, C.W., "Discussion on Pontiac Recalcining Plant", Journal AWWA. Vol. 40, No, 4, pp.
466-467, April 1948.
Key Words: Calcium carbonate, Recalcining
The C-E Raymond Flash Drying System rapidly dries materials in the fine to granular form. The
complete conversion of a dewatered centrifuge calcium carbonate cake to a dried and preheated
powder requires a few seconds. The calcining furnace decomposes calcium carbonate to quicklime
and collects the finished product. The positioning of the oil burners is critical for short
duration complete calcining. At Marshalltown, Iowa, and 80% lime content is reclaimed out
of a theoretical 84% content. Coagulation with the reclaimed lime is excellent. Furnace
temperatures are traced throughout the systems. Flash drying is of the two-stage, counter-
flow type. At Marshalltown, one ton of high quality finished lime is produced with a fuel
consumption of 9.66 million BTU. The power consumption is 60 kwhr/ton finished lime.
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Sowden, H.H., "Lime Recovery from Water Softening Sludges", Journal AWWA. Vol. 33. No. 4,
pp. 741-748, April 1941
Key Words: Sludge treatment, Calcining, Vacuum filtration
This study discussed experimental calcining of softening sludge to produce a reuseable lime
product and a method to determine percent solids in the sludge. Turbid matter is removed by
alum coagulation in-separate basins before softening. Coagulant aids interfered with vacuum
filtration dewatering. Filtration rates of 2010#/ft2/24 hr were achieved on unconditioned
precipitator sludge. A 57. CaO solution increased dewatering while powdered coal, carbon
dioxide, bentonite, and heat treatment were not effective. Savings are realized in the
purchase of new lime and sludge disposal costs. Tabulations of lime analyses are presented
for calcination experiments. A 2-5% solids softening sludge from the precipitators is
thickened by natural subsidence and mechanical means to 20-30% solids. An experimental
vacuum filter concentrates solids to 60%. Air drying reduces moisture content to 10%. Sludge
is calcined in a muffle furnace at 2000°F till completely burned. A formula, based on weight
and volmetric considerations, is derived to determine percent sludge solids. Excess lime
should be recovered. Economic feasibility depends on: new lime cost; calcining expenditures;
and sludge disposal criteria.
Swab, B.H., "Pontiac Recalcining Plant", Journal AWKA. Vol. 40, No. 4, pp. 461-464, April 1948.
Key Words: Water softening, Calcining
The City of Fontiac incorporated provisions to dry 28 tons/day of calcium carbonate sludge and
recover the lime at their softening facility. The three stage operation included: dewatering,
classifying, and rejecting a portion of the magnesium and other impurities by continuous centri-
fugation; drying in the Raymond Flash Drying System; and recalcination by exposing dried material
to a temperature of 1900°F. The carnonate percipitate is transported to slow-speed stirring
slurry.receiving tanks. Concentrated slurry is discharged to two continuous centrifuges. The
magnesium and other impurities are passed to the sanitary sewer and the calcium carbonate is
conditioned prior to flash drying. The flash drier is composed of a cage mill and blower.
Dried material is calcined in a furnace with the CaO sent to storage bins. The maximum operating
cost per ton (CaO) is $7.95.
Kinman, R.N., "Magnesium Carbonate for Water Treatment", Presented at First Sanitary Engineering
Seminar, Central Ohio Section, ASCE, March 27, 1972, 11 pp.
Key Words: Magnesium carbonate, Surface water, Drum process wastewater
This compared MgC03 as a coagulant for Ohio surface waters and variable drum process wastewater
with alum and lime. A pH titration curve using Ca(OH)2 was run on four surface supplies. The
lime dose to produce a pH of 11.3 was added to 500 ml samples and mixed at 100 rpms for 1 minute
and 30 rpms for 20 minutes. Samples were settled for 20 minutes. Five minutes time was generally
efficient for the rapidly settling Mg(OH)£ floe. Physical-chemical data are tabulated for different
chemical doses on samples from the Ohio River, Licking River, Little Miami River, and Muddy
Creek. Composite samples from steel drums were tested. These wastes include NaOH, detergents,
sanitary sewage, oil, or anything that can be shipped by drum. The pH was 12.2 with a high COD
value. A pH of 11.3 was attained by using HC1. Mixing was at 100 rpms for 3-5 minutes and
30 rpms for 20 minutes settling. Physical-chemical data are tabulated for coagulation of drum
processing wastewater. MgCOs, hydrolyzed with lime, effectively removes color, turbidity, COD,
and other impurities. Flocculation and settling require less time than alum and could alleviate
sludge disposal problems. Economic, operational, plant instrumentation, and efficiency evaluations
are being made on pilot and plant scale basis in Montgomery, Alabama.
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Thompson, C.G., et al, "Magnesium Carbonate - A Recycled Coagulant", Journal AWWA. Vol. 64,
No. 1, pp. 11-19, January 1972.
Key Words: Magnesium carbonate, Modified technology
This study described the development of a coagulant system that effectively reduced organic
color and turbidity and eliminated major sludge disposal problems. A low-cost source of MgC03
is under development. The major process reaction chemistry is described. The jar test parameters
examined were coagulation pH, forms of alkalinity and hardness, settled water color and turbidity,
electrophoretic mobility, residual magnesium, stabilized water character, and visual floe properties
and settling rates. Type, grade, and preparation of materials used are described. A filter
photometer is utilized for measuring color and turbidity and a zeta meter for electrophoretic
mobility. Jar testing procedures are outlined. Laboratory separation of carbonated sludge
containing soluble MgC03 and insoluble CaCOs and clay is accomplished by filtration through Whatman
No 40 paper. Linear regression analyses of MgCOj dosage with color and turbidity were made.
The heavy magnesium hydroxide floe increases present plant capacity. Recycled MgC03 was as
effective as new MgC03.
Thompson, C.G., Singley, J.E. & Black, A.P., "Magnesium Carbonate: A Recycled Coagulant-II",
Journal AWWA. Vol. 64, No. 2, pp. 93-99, February 1972.
Key Words: Magnesium carbonate , Coagulant recovery
This .article suggested the utility of magnesium carbonate to remove organic color and turbidity
at water purification plants and alleviate sludge disposal problems. A linear regression of
log MgC03'3H20 versus pH is shown. Chemical treatment costs depended on CaO required for pH
control; C02 to solubilize Mg(OH)2 in the sludge and reduce high pH of treated water; and
make-up MgC(>3. Lime recovery can supply quicklime and C(>2. Cost curves are prepared. Cost
data are tabulated for 17 natural waters including Atlanta,Baltimore, and Washington. A
linear correlation existed between electrophroetic mobility and residual turbidity. A
significant relationship was shown between particle mobility and residual turbidity when
alum was used as a coagulant aid. The new treatment should remove and disinfect bacteria and
viruses. A contact time of 4 hours and pH of 11.0-11.5 should be sufficient for disinfection.
An equation for minimum Mg(OH)2 as MgCC^'SH^O was determined based on water color, turbidity,
total alkalinity, and total hardness. Carbonation does not release color in waters of 150 or
less color units. A more elaborate recovery process or wasting of recovered solution is
necessary on highly colored water. A flow diagram is prepared. Pilot and plant scale work
is underway at Montgomery.
Vahidi, I., "Recovery of Waterworks Sludge", Journal of the Institution of Water Engineers,
Vol. 12, No. 3, p. 211-212, May 1958.
Key Words: Biological methods, Alum recovery
Trivalent metallic ions such as Al+3 and Fe+3 neutralize negatively charged colloids causing
particles to coalesce. The dumping of alum sludge on land makes it worthless for agricultural
purposes. Fundamental research is aimed at studying the sludge nature and the way the coagulant
is found to coagulate water. The method of investigation includes: study of nature and
quantity of sludge produced in water treatment plants; treatment of wet sludge obtained by
biological methods such as aerobic digestion and anaerobic digestion followed by aerobic
digestion; and chemical treatment of oxidation followed by extraction with acid. Planned
laboratory testing to aid in the control of digestion and alum recovery are: fixed and volatile
solids analyses on raw sludge and digestor samples; pH; A1203 determination by gravimetric
method following acidification and paper filtration of sludge; and spectropotometric analysis
of iron. Preliminary tests show anaerobic digestion of alum sludge improves recovery operations.
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Vahidi, I. "Recovery of Waterworks Sludge-II1,' Journal of the Institution of Water Engineers
Vol. 12, No. 7, pp. 491-492, November 1958.
Key Words: Digestion, Alum recovery
Water purification sludge can either be dewatered, dried, and disposed of cheaply or the
coagulant can be reclaimed for reuse with final disposition of the sludge commercially if a
market can be found. Raw sludge at the Thockley Filtration Plant is slightly alkaline and
odorous following the establishment of anaerobic conditions in lagoons. The sludge contains
organic matter, humlc acid, aluminum hydroxide(40% ^203) and ferric hydroxide (4% FeoOO.
Digestion was studied using 2 liter batch samples of raw sludge and 2 liter samples of digested
sludge. The digested sludge is treated with I^SO^ with the mixture filtered through paper.
Recovered alum data is tabulated. Laboratory work showed anaerobic digestion of alum improved
alum recovery. A potentially applicable solution is the aeration of the sludge in the
presence of certain bacteria species. Laboratory-bench scale and aeration tank experiments
are planned along this line.
Vahidi, I., and Isaac, P.C.G., "Recovery of Water Works Sludge", Journal of the Institution
of Water Engineers, Vol. 14, No. 6, pp. 454-458, October 1960.
Key Words: Centrifugation, Alum recovery
This paper described the laboratory investigation of alum recovery for water works clarification
sludges. The purification sludge character includes: aluminum hydroxide; peat; algae; silt;
and organic matter. The acidification of insoluble aluminum hydroxide recovers an alum solution
and greatly reduces settling time and final volume of the settled sludge. Part of the precipitated
organic color and iron salts can be built up in the recovered solution. In the laboratory,
a 1.5-2.5% sludge solution was acidified and centrifuged. The centrate, reclaimed alum, was
used for coagulation. A 60-65% recovery at pH of 3 had the best relative efficiency. An average
yield of 1.5.tons of aluminoferric (14% ^203) is produced for consuming one ton of 98% sulfuric
acid. This wet alum recovery process reduces sludge volume for disposal. Costs are considered.
The total treatment includes: transporting 1.5-2.5% sludge solution to collection tanks;
acid-treatment system; recovered alum separation by centrifugation; pumps, piping, and valves for
recirculation of recovered supernatant; solution-storage tanks; and drying beds for the remaining
sludge.
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WATER TREATMENT PLANT WASTES
Treatment1 of Sludges
Dewatering Processes
Albertson, O.E. & Guidi, E.J., "Advances in the Centrifugal Dewatering of Sludges", Water &
Sewage Works. Vol. 114, R.N., pp. R142, 1967-
Keywords: Centrifugation, Machine variables, Process variables
This study outlined the utility of centrifugation to treat sanitary and industrial wastes.
An early history of perforated and inperforate basket, solid-bowl, and disc-valve centrifuges
is presented. Conical centrifuges classify and dewater,cylindrical units recover fine particles
in clarification, and cylindrical-conical devices are most suitable for clarification and
maximum solids concentration. Solid bowl centrifuges are described. Machine and process
variables are discussed. Machine variables include: bowl design with length to diameter ratio
and bowl angle; bowl speed; pool volume (depth); conveyor speed; and pitch. Process variables
include: feed rate; solids character with particle size and density; feed consistency;
temperature; and chemical aids. Recovery is improved by increasing bowl speed and decreasing
conveyor speed. A test program was run on raw primary and secondary digested sludge; pulp
and paper wastes; and water softening sludges. Centrifugation increased solids concentration
to 53-57% and recovery 79-93% for water softening waste. Tabulations are made for recovery-
concentration data on tested wastes. Centrifugation advantages are listed.
Crook, J., "A Study of the Dewatering of the Cincinnati Water Treatment Plant Sludge by
Centrifugation", Thesis Presented to Department of Civil Engineering, Division of Graduate
Studies, University of Cincinnati fpr Master of Science, 1969S 95 pp.
Key Words: Centrifugation, Sand drying beds
The utility of centrifuging and sand-drying coagulation sludge in laboratory scale unit is
examined. A literature review of sludge disposal techniques is prepared. A history of
centrifugation including types, machine and process variables, economics, and advantages
is presented. Sludge from the Cincinnati water treatment plant is evaluated. Laboratory
and analytical methods are enumerated for sludge collection and storage, sample preparation,
centrifugation equipment and techniques , drying beds, and polymer addition to the waste.
The pH, COD, raw sludge solids concentration, settling analyses, centrifugation of raw
sludge with and without polymer aids, centrate suspended solids removal, and sand drying
bed efficiency are evaluated. Cake solids concentrations and centrate recovered increase with
centrifugation speed and detention time. Presettling wastes before centrifugation appeared
beneficial. Drying rates were comparable for raw and centrifuged sludge. Bench-scale
centrifugation testing and drying bed development studies are recommended.
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Keith, F.W., "Dewatering of Water Treatment Alum Sludge by Centrifugatlon", Paper Presented
at 21st Annual Meeting of Pennsylvania Section AWWA, Pittsburgh, Pa., June 24-26, 1969
(Unpublished).
Key Words: Centrifugation, Basket centrifuge
This study described the utility of an imperforate bowl basket centrifuge to effectively
dewater alum sludges. Imperforate conveyor centrifuges can produce a 60 percent lime sludge
aolids cake while selectively classifying magnesium hydroxide. The bowl basket centrifuge
can be operated continuously with cyclic cake removal and adaptability to feed solid quality
changes. The unit is automatable, requiring no coagulant and creates the least degradation
of delicate alum hydrogel floe. Studies in England and the United States indicated 0.5 to
1.5 gpm of sludge is produced per mgd of plant capacity. Regression analyses were performed
using sludge concentration, turbidity, centrifugal field residence time, and centrifugal
acceleration data. Cake concentration depended on sludge compactability and centrifugal
field residence time. A potential flow diagram to handle sedimentation tank sludge and
filter washwater is presented. Recoveries of 90 to 98 percent were achieved at Pickering
Creek Water Treatment Plant with this centrifuge.
Townsend, J.R., "What the Wastewater Plant Engineer Should Know About Centrifuges/1",
Water and Wastes Engineering. Vol. 6, No. 11, pp. 42-44, November 1969.
Key Words: Centrifugation, Operating variables
This article described types of centrifuges and operating variables to be considered in their
selection. Centrifuges clarify and classify solid-liquid slurries and separate liquids.
Important factors are effective and theoretical capacity. Effective capacity is the slurry
volume of a fully loaded centrifuge divided by the time to remove one-half the suspended parti-
cles. Theoretical capacity is an areal dimension of the gravity settling tank providing
separation equivalent to Centrifugation. Selection of a unit depends on solid removal require-
ments, shutdown time, and cost. The three best types of wastewater applications are the
basket, disc, and continuous discharge decanter. A nozzle discharge centrifuge is most suitable
for water treatment plants. Tests were run on a municipal activated sludge. The suspended
solids recovery was plotted against the feed flow rate/theoretical capacity for three units.
The disc centrifuge was the lowest cost machine per unit of capacity, but maximum sludge
concentration was achieved in the basket type centrifuge. Centrifugation capabilities
including: bowl diameter; flow rate; feed solids; discharge solids; temperature and pressure
ranges; speed; gravity forces; motor power; and particles removed are tabulated for four
machines.
Townsend, J.R., "What the Wastewater Plant Engineers Should Know About Centrifuges/2", Water and
Wastes Engineering. Vol. 6, No. 12, pp. 35-37, December 1969.
Key Words: Centrifugation, Machine variables
The article outlined operating and cost factors, selection rationale, maintenance procedures,
and applications for Centrifugation. Operating factors included: maximum flow estimation;
liquid requiring clarification; type and present solids concentration; system pressures; chemical
conditioning; screens; and preconditioning equipment. Cost factors were: installed equipment
cost; interest on'money; amortization expenditures; plant space requirements; power; operation
and maintenance needs; down-time; and standby equipment for 100% operation. An ideal centrifuge
is described. Practical parameters considered were maximum allowable solids in effluent;
moisture content of solids; space requirements; available capital; gravity forces and speed
effect on effective capacity; liquid depth; length to bowl diameter ratio; and volumetric capacity.
Each Centrifugation application must be examined on its own merits. Items require checking.
These are: bearing lubrication: power consumption; line voltage regulation; vibration limits;
visual inspection; and unusual noises and odors. Inspection intervals are once each six months.
Paper mill, municipal, refinery, steel mill, and water treatment plant wastes are tabulated for
solid-bowl scroll, disc-type nozzle, and solid-bowl basket machines.
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Clark, E.E., "Water Treatment Sludge Drying and Draining on Sand Beds", Water Quality Office,
EPA, Research Grant 17070-DZS, and Research Fellowship 1-F1-WP-26-453-01, Report No. EVE24-70-4,
August 1970.
Key Words : Sludge treatment, Sand beds
The objectives of this study were: define chemical-physical properties of wastes; assimilate
technology from other disciplines for use; develop non-destructive moisture or solids content
measurement methods: develop experimental apparatus and methods for studying sand bed dewatering;
determine applicability of sewage sludge predictive formulations for water plant wastes; and
apply results to engineering design. Information is provided on the problem background,
historical development, theoretical consideration; materials and apparatus; methodology; and
results. Sludge from alum coagulation with and without iron removal and activated carbon addi-
tion and lime-soda ash waste are tested. The study showed: chemical properties varied widely;
drying and drainage accounted for majority of water removal; drainage times and drying durations
can be predicted; moisture gradient is constant during dryings; and gamma-ray attenuation is
applicable to sludge drying studies. Research and design recommendations are made.
Gauntlett, R.B. and Packham, R.F., "The Dewatering of a Clarification Sludge on Drying Beds",
Journal of the Institution of Water Engineers. Vol. 26, No. 4, pp. 185-200, April 1972.
Key Words : Sludge treatment, Water treatment, Water purification, Clarification sludge,
Sand drying beds
Eight experimental sludge drying beds at the Godley Works of the Manchester Corp. Water Dept.
were used to compare a coarse and filter grade sand support medium as a cheap alternative to
wedge wire, with the essential features of wedge wire bed operation being retained. The
following conclusions resulted. Drying beds of suitable construction effectively dry waterworks
clarification sludge during months when evaporation proceeds at a reasonable rate. The cost of
such beds can be minimized by the use of a suitable grade of sand as an alternative to more
expensive forms of drainage media, but some means of controlling the drainage rate is essential,
unless polyelectorolytes are used. Translucent covers on the beds during all except the summer
months is advantageous, and some saving in time and cost is possible by "layering" the sludge,
although this practice leads to deterioration in drying performance. The main disadvantages of
this sludge drying method are the very slow drying rate during the winter months and the large
land area required. The drainage phase of the drying process is unaffected by seasonal
climatic changes in a covered bed, and the possibility of using drainage alone, aided by
polyelectrolytes, as a preliminary to some other sludge-drying process should not be over-looked.
MeWain, J.D., "Dewatering by Lagoons and Drying Beds", Proceedings Tenth Sanitary Engineering
Conference, Waste Disposal from Water and Wastewater Treatment Processes, University of Illinois,
Urbana, pp. 63-76, February 6-7, 1968.
Key Words : Lagoons, Sand drying beds, Asphalt-paved beds.
This study presented observations, analyses, and investigations on: drying bed dewatering of
aerobically digested sewage sludge; and lagoon and drying bed dewatering for upflow clarifier
sludge from water treatment plants. Handling and disposal options for aerobic sludge included
centrifugation, air flotation-vacuum filtration, and drying beds. Sand drying beds dewatered
sludge by draining and evaporation. Shallow loaded beds dewatered rapidly with solids con-
centration times inversely proportional to initial bed depth. Evaporation was independent of
bed depth. A homogeneous sludge concentration of 25% reduced volume by 85%. Dewatering on
asphalt-paved beds produced a 20% sludge content of the initial volume. Clarification sludge
from the Shoremont and Wolcott Plants was tested for lagoon and drying bed dewatering. Core
samples from the lagoons showed this method unable to produce a 20% sludge. Pilot testing
was initiated. Temperature, relative humidity, sand size, drainage time, drying time, total
dewatering time, and final filtrate suspended solids concentrations are tabulated. A 1% sludge
required 100 hours to produce a 20% cake with a filtrate of 240mg/l suspended solids. A bed
loading of 0.784 pound drying solids /ft^ was needed. A 1.0 mm effective grain size was
unsatisfactory for sludge dewatering.
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Nebiker, J.H. & Adrian, D.D., "Cost Evaluation of Sand Bed Dewatering and Drying of Waste-
water Sludges", Filtration and Separation, May/June 1969, 4 pp.
Key Words: Dewatering, Drying, Sand beds, Digital computer simulation
Approximately 72% of U.S. plants use sand beds to provide filtration by gravity dewatering
and drying by evaporation. Little research has been directed to optimize design. This paper
presents a rational formulation, or simulation, to describe sand bed operation based both on
dewatering and drying processes. Independent formulations are presented for dewatering and
drying. Drying rates are dependent on moisture content. A sludge dewatering-drying model
is provided with initial constraints on: initial solids content; specific resistance;
coefficient of compressibility; drying intensity; depth of sand and supporting media; and
quantity of sludge produced each day. Boundary conditions for method of operation were sludge
depth applied and final moisture content desired. Cost criteria included: land; construction
of sand beds; maintenance; periodic repairs; salvage land value; and application and removal
of sludge. Cost data are developed for different conditions. Digital computer simulation
is applied. A method to optimize application depth for sludge and predict costs by
simulation is shown.
Ralph, B. Carter Company, "Carter Automatic Belt-Filter Press", Technical Publication 4 pp.
t
Key Words: Dewatering, Filter press
This.article describes the design principles and general operation of a filter press to
dewater municipal and industrial wastes. The filter media is a multi-composition coarse
mesh fabric. Polymers bridge the solid particles and accelerate dewatering in a pre-
treatment sequence. The pressure for filtration is adjustable. Maximum pressure should
be the point where sludge cake is retained on the filter belt and floe particles are not
broken. Destroyed floe particles can pass the fabric or clog the filtration media. Equations
describe dewatering in the drainage, press, and shear zone. Industrial sludges and twenty
municipal sludges were dewatered by filter press in Germany. Data are tabulated for raw
sludges, primary digested sludges, and mixed digested sludges from primary and secondary
sewage treatment. These data include: sludge and presscake moisture content; water removed;
sludge; and dry solids throughout; flocculant cost; power consumption; attendance time; and
total operating cost. In England, data were tabulated for domestic and industrial waste,
including pharmaceutical and brewery waste. Limited cost data compares filter pressing to
sand bed drying and vacuum filtration of specific wastes.
Logsdon, Gary Steward, "The Mechanism of Water Plant Sludge Dewatering by Freezing", Private
Communication, March 1971.
Key Words: Freezing, Sludge
An investigation was carried out to determine the mechanism by which water treatment plant
sludge is dewatered upon freezing. A review of literature revealed that a limited amount of
theoretical work had been done on this topic in sanitary engineering. However, extensive
literature on soil freezing and sea water freezing was available, and it proved useful in
understanding what happens when sludges freeze. Experiments were planned so that there
would be similarities between sludge freezing tests and earlier work in other fields. Sludge
samples were frozen by lowering them into an antifreeze bath. Thus freezing velocity could
be controlled and comparison of sludge freezing and soil freezing research could be made.
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logsdon, G.S. & Edgerley, E., "Sludge Dewatering by Freezing", Journal AWWA. Vol. 63, No. 11,
pp. 734-740, November 1971.
Key Words: Freezing, Water-solids separation, Sludge dewatering
Freezing tests on laboratory hydrous alum and ferric sludges and water treatment plant sludge
are described. Sludge-freezing and soil-freezing literature is reviewed. Conclusions on
sludge freezing speed, freeze length, thaw period, and solids content are made. Freezing
changes are irreversible. Factors influencing soil-frost heave are enumerated. Data relates
freezing speed to sludge dewaterability for test sludges. Settled volume concentrations of
frozen-thawed sludge were one-half to one quarter of unfrozen settled volumes. Macroscopic
or microscopic migration of solids particles: is required for good water-solids separation and
dewatering. Flash freezing is ineffective. Polymers that reduce sludge specific resistance
can increase the gross-solids migrations during freezing. Freezing speeds of 60 mm/hr appear
effective. Polymers can increase the freezing speed. Compressive forces are not necessary
for good dewatering of frozen sludge. Spray nozzles should spread thin layers of sludge
on frozen sludge beds for efficient natural freezing.
Falton, G.P., "Appendix A, Vacuum Filtration of Water and Sewage Waste Sludge", Private
Communication, March 1971.
Key Words: Vacuum filtration, Alum sludge
The present Town of Yorktown sewage treatment plant is located reasonably close to the general
area proposed for the new Amawalk water treatment plant. Because of the proximity of the two
sites, it was thought advisable to investigate the possibility of disposing of the alum sludge
wastes from the water treatment plant along with the sewage plant sludge. The sewage treatment
facility is a high-rate trickling filter plant utilizing digestion, vacuum filtration, and
landfill to dispose of the settled sludge. Studies were conducted to determine the optimum
chemicals and dosages for the vacuum filtration of the digested sludge, and to assess the
additional cost of filtration of a mixture of digested sludge and water treatment plant sludge.
Conditioning with 3% ferric chloride and 13% lime provided the best results in the vacuum
filtration tests.
Mahoney, Patrick F. & Duensing, Willard J., "Precoat Vacuum Filtration and Natural-Freeze
Dewatering of Alum Sludge", Journal AWWA. Vol. 64, No. 10, Part 1, pp. 665-669, 1972. Summary
of Mahoney & Duensing report was also published in American City, Vol. 87, No. 12, p. 42, December
1972, under title "How to dewaterwater treatment sludge."
KeyWords: Dewatering, Rotary vacuum precoat filtration, Natural freezing
This paper described considerations in a testing program to determine critical parameters
to dewater gelatinous aluminum hydroxide sludge economically, EPA provided funds for a
pilot facility to: demonstrate the technical feasibility of dewatering alum sludge by rotary
vacuum precoat filtration; determine optimum operating conditions; develop plant scale cost
estimates; describe the effect of natural freezing on dewatering of dilute and concentrated
sludge mixtures; and determine the optimum maximum layer thickness to be frozen. The rotary
vacuum precoat filtration operation is described. The variables studied included: sludge
solids cake; filter aids; drumspeeds; knife advance rate; filter drum submergence; filter
rate; cake moisture; and filtrate quality. Sludge was pumped from the settling basins to a
constantly agitated feed tank, then to a filter bowl. A 20# cake solids with filtrate
quality <5 JTU was achieved at 5 gal/ft2/hr. The cake can be used as landfill. Polymer
conditioning was not beneficial at Albany. Sludge treatment costs are estimated at $6.05/mg
treated water and $9.25/1000 gal of sludge. A 4' sludge depth was frozen in layers. Good
liquid-solids separation was obtained following thawing.
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Nebiker, J.H., Sanders, T.G., and Adrian, D.D., "An Investigation of Sludge Dewatering Rates",
Journal WPCF, Vol. 41, No. 8, Part 2, pp. R255-R266, August 1969.
Key Words: Sludge treatment, Gravity dewatering, Sludge handling.
Sludge handling for primary and secondary treatment total 25-65% of total operating and
capital costs. Emphasis should be placed on volume reduction before ultimate disposal.
Parameter formulations and laboratory tests are needed for gravity dewatering. Details are
provided on previous research. Possible parameters for gravity dewatering are: sludge depth,
sludge permeability, final solids content, and character of supporting media. Formulations
are presented for determining specific resistance and the coefficient of compressibility.
Gravity dewatering experimental apparatus and procedure are also described. Solids content,
specific resistance, coefficient of compressibility, and uniformity coefficient data are
tabulated for dewatering of mixed digested sludge on sand media, Standard divergence
between theoretical and experimental values was 50%. The theoretical formula, verified by
experimentation, shows initial solids content, filtrate viscosity, depth, specific resistance,
and coefficient of compressibility to be important. Coarse media increase drainage rates
but produce more turbid filtrates. Influence of polymers on coefficient of compressibility
is needed. This work should be applicable to water treatment wastes, industrial sludge,
liquid manure, and benthic deposits.
Kovach, M.P. (with Polkowski, L.B.) "Thickening and Dewatering Properties of Water Treatment
Plant Sludges". Thesis presented to Dept. of Civil and Environmental Engineering, University
of Wisconsin, p. 43, Fig. 16, Tab. 12, Ref. 19.
Key Words: Water softening, Dewatering, Sludge, Alum sludge, Lime softening sludge,
Solids flux concept, Vacuum filtration
Sludge samples from five lime softening and five alum clarification treatment plants in
Wisconsin and Minnesota were studied in relation to both their thickening and dewatering
properties. The concept of solids flux was applied to the investigation of the thickening
properites. Individual batch settling tests on the sludge samples revealed that sludge depth
and column diameter, as well as cold storage of samples for prolonged periods, did not affect
the initial settling velocity of the sludge interface. Daily variations in thickening
properties of lime softening and alum clarification sludges underscored the importance of
analyzing numerous samples from a particular plant in order to determine the maximum range
and probability relationships for thickening area requirements. Vacuum filtration properties
were examined by the Buchner funnel and filter leaf tests. Suspended solids concentration of
sludge exerted a significant effect on the specific resistance of most lime softening and
lime conditioned alum clarification sludge samples. Lime softening sludges tended to dewater
to a higher cake solids concentration and at a greater filtration rate than lime-treated
(pH 11.0-11.5) alum clarification sludge samples. Day-to-day variations in dewatering prop-
erties occurred for both lime softening and lime-treated alum clarification sludge samples.
Lime softening sludge samples generally dewatered to a drier cake concentration and at a
greater loading rate than lime-treated alum clarification sludge samples.
Scolari, E., "Reclaiming Water from Water Plant Sludge", Public Works, Vol. 99, No. 6, p. 100,
June 1968.
Key Words: Water reuse, Drying beds
This article showed how the recovery of supernatant from sludge drying beds could produce a
treated water cost savings. Water treatment included lime-soda softening, clarification,
recarbonation, and vacuum type diatomite filtration. Some sludge is recirculated. It was
feasible to reclaim the highly treated sludge supernatant rather than discharge this liquid
to the sewer system. An asbstos cement lined pipe intercepted decanted water and returned
this water to receiving wells by gravity flow. Pumps, automatically operated by float switches,
returned this water to the flocculating part of the treatment facilities. Final installed
costs were less than $6526. The first year the plant reclaimed 36 mgd of water with a treated
water cost value of $8394. Second year recovery exceeded 43 mgd with a cost value of $10,563.
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Stoll, B.J., "A Laboratory Study of Water Treatment Sludge Treatment Handling, Conditioning
and Dewatering Techniques", Thesis Presented to Department of Civil Engineering, Division of
Graduate Studies University, of Cincinnati, for Master of Science, 1970, 82 pp.
Key Words: Filtration, Centrifugation, Settling
This study evaluated the settling, filtration, and centrifugation of raw and polyelectrolyte
conditioned coagulation sludge from the Cincinnati Water Treatment Plant. Important process
parameters were identified and analyzed. Literature was reviewed on the bridging action of
polyelectrolytes as conditioning agents and coagulant dosage optimization considering initial
sludge solids content, sludge volume filtered, filter surface area and pressure. Sludge
sampling and storage procesures, conditioning agent preparation, sludge solids content, and
laboratory dewatering analyses are discussed. Data are tabulated and graphed for settling,
filtration, and centrifugation tests on raw and polymer conditioned sludge. A cationic
polyelectrolyte effectively conditioned sludge for dewatering by filtration or centrifugation.
Settling was a good pretreatraent method to make sludge amenable" to dewatering by filtration
and centrifugation. Additional work suggested included: investigation of coagulant dispersion
and mixing techniques; pilot filter and centrifugation studies of raw and polymer conditioned
sludge.
WATER TREATMENT PLANT WASTES
Treatment of Sludges
Sludge Conditioning
Doe, P.W., "Use of Polyelectrolytes as a Sludge Conditioner", Paper Presented at the Poly-
electrolytes Seminar, Annual AWWA Conference, June 4, 1972, Chicago, Illinois.
Key Words: Polyelectrolytes. Specific resistance, Compressibility index
Raw water quality and treatment processes utilized influence sludge production. Polyelectrolytes
have applicability as primary coagulants, coagulant aids, and sludge conditioners. The prime
purpose as a conditioner is to prepare thick gelatinous type sludges for disposal. Polymers
can strengthen floe particles and aid sludge dewatering. Trial and error selection processs
are necessary. A polyelectrolyte sludge conditioner can alter the physical character or
thickened sludge. The greatest practical use is pretreatment before filter pressing. A
basic filtration equation is presented. Lowering the coefficient of specific resistance and
compressibility index increases the process efficiency. Polyelectrolytes help produce a
handleable cake that is easily removed from the filter cloth. The article concludes: high
molecular weight non-toxic polyelectrolytes must be used in all water filtration plants where
supernatant could be returned to the plant inlet; laboratory testing is required; liquid form
polymers are more easily and economically handled; and polyelectrolytes help produce a good
filter press cake with a less obnoxious filtrate.
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Vogh, R.P., Warrington, J.E. & Black, A.P., "Potato Starch as a Sludge Conditioner", Journal
AWWA, Vol. 61, No. 6, pp. 276-284, June 1969.
Key Words: Flocculation, Activated silica, Potato starch
Activated silica was used as a flocculant aid to settle softening precipitates at a Florida
water treatment plant. Activated silica conpacted the sludge to a resistance where torque
complications made reactor operation difficult. Jar tests were run using alum, ferric sulfate,
cold water starch, anionic polymer, cationic polymer, carboxymethyl cellulose, lignosulfonate,
and magnesium sulfate. Cold swelling potato starch proved effective and economical in barrel
tests conducted on 55 gallon water samples. Sludge conditioned by potato starch occupied 50%
of the settled volume of activated silica sludge. A more turbid water entered the filter from
the starch treatment, but did not decrease filter runs. Potato starch eliminated torque in
the plant. A 1% feed solution is used. A delivery system is detailed. Potato starch is
cheaper than activated silica for Gainesville. An instrument is illustrated and method
described to evaluate potential torque considerations. The action of potato starch is described
in producing a mobile and soft sludge.
WATER TREATMENT PLANT WASTES
Treatment of Sludges
Types of Wastes
Albrecht, A.E., "Disposal of Alum Sludges", Journal AWWA. Vol. 64, No. 1, pp. 46-52, Jan. 1972.
Key Words: Flotation, Alum recovery
This study enumerated present disposal methods for purification and softening wastes and
investigated four alum sludge treatment procedures. Alum sludge character includes: insol-
ubility in natural pH water; settleability yet not easily concentrated or dewatered; and
ability to clog soil when disposed on land. Recycling of supernatant from the sedimentation
of filter washwater is suggested. Advantages, disadvantages, and concentration considerations
are provided for alum sludge treatment by discharging to surface waters and sanitary sewers,
thickening sand drying beds, lagooning, filter pressing, vacuum filtration, centrifugation,
and freeze-thaw processes. Laboratory investigation and test procedures are explained for
alum recovery, flotation and vacuum filtration, and the mixing of alum sludge with raw sewage.
The laboratory study effectiveness is discussed. Acidified alum sludge was amenable to dewatering
by flotation and vacuum filtration. The study recommended pilot-plant work on alum recovery
and mixing of the purification waste with raw sewage.
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Neubauer, W.K., "Waste Alum Sludge Treatment", Journal AWWA. Vol. 60, No. 7, pp. 819-825,
July 1968.
Key Words: Dewataring, Landfills, Alum sludge
This study evaluated four alum sludge dewatering methods at two water purification facilities.
Coagulation waste character includes: chemical precipitates with organic debris, high moisture
low solids content, easily settled-difficultly handled, and insolubility in natural water pH.
Analyses for total, suspended, volatile-suspended solids concentrations of clarifer sludge
were made in accordance with Standard Methods. Some density,BOD, COD, and pH measurements
were taken. Performance criteria were based on a 20% total solids content for landfill disposal
following conventional settling to reach 1% solids concentration. A Buchner funnel simulated
vacuum filtration in the laboratory. Raw sludge and cake solids content, filter loading rate,
drying time, liquid viscosity, and operating vacuum were considered. A precoat was needed
to achieve 20% solids. Filtrate analysis showed 99% suspended solids, 50% BOD, and 95% COD
removed. Bench scale centrifugation and plant size lagooning could not produce a 20% solids
concentration. A 20% solids level could be reached by sand drying in 100 hr with a loading
rate of 0.8 Ib/ft^. Filtrate can be recirculated to the treatment plant influent. Capital,
operating, and maintenance costs are estimated for vacuum filtration and sand drying. Treat-
ment costs were less than $5/million gallons of raw water processed.
Young, E.F. "Disposal of Sludge from Sedimentation Plants, with Special Reference to Alum
Sludge", Ninth International Water Supply Congress, New York , 1972. (To be published.)
Key Words: Sludge disposal, Water purification, Water treatment, Alum sludge,
Dewatering processes
The results of a general questionnaire circulated to member countries (Bulgaria, Denmark,
Finland, Hungary, India, Ireland, South Africa, U.K. .U.S.A., and U.S.S.R.) disclosed that
sludge disposal was a problem to relatively few members. The spread of data covering type
of raw water, sedimentation tank, and thickness indicated that sludge quantities and
characteristics varied according to the raw-water characteristics and the design and manner
of desludging of the sedimentation tanks. The appendix of the report summarized data on
sludge quantities, but excludes information from the U.S.A. and Great Britain, in view of
the large volume of published data available. The following treatment processes and matters
^n the reporting countries were briefly reviewed: sedimentation tanks, sludge concentration,
concentrator chambers, settlement and thickening tanks, chemical conditioning, sludge lagoons,
draining and drying beds, filter pressing, centrifuging, vacuum filters, alum recovery,
freezing and thawing, and'sludge pumping. Huge quantities of alum sludge in the future will
pose problems of disposal in a growing number of nations.
King, P.H., Olver, J.W., Randall, C.W., and Caskey, J.A., "Conditioning and Disposal
of Ferric Sulfate Sludges", Presented at Fourth Annual North East Regional Antipollution
Conference, Univ. of Rhode Island, Kingston, R.I., 25 pp., 1971.
Key Words: Dewatering, Polyelectrolytes, Filtrability
Synthetic organic polyelectrolytes conditioned ferric sulfate sludges for dewatering by gravity
drainage and vacuum filtration. Previous work revealed successful polymer conditioning
depended on sludge character, nature of polyelectrolyte used, and the time and manner of
polymer addition. Polymers have been able to: decrease specific resistance of sludge; improve
alum sludge drainability; be most effective with molecular .weights of 1,000,000 or more ar.d
when added to sludge following settling; and increase dewatering rates in vacuum filtration
OTf open sand drying beds. 500 ml samples of a ferric sulfate - lime sludge were pH adjusted.
Polymer doses of 0-190 ppm were mixed with sludge for 2 minute periods at 100 rpms. This
speed kept the system homogeneous and prevented premature settling. Parameters studied were: pH
sludge solids concentration, nature and dose of polyelectrolyte, specific resistance of condi-
tioned sludge, zeta potential and drainage rates. Results indicated: synthetic organic
polymers improved ferric sulfate sludge dewaterability; optimum pH range was near neutrality;
sand bed drying was effective; and no correlation existed between zeta potential and improved
filterability. Polymers form chemical bridging mechanisms between floe particles.
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Lewandowski, G.A. & Linford, H.B., "Filtration of Ferric Hydroxide", Environmental Science
and Technology. Vol. 6, No. 2, pp. 169-172, February 1972. '
Key Words: Filtration, Filterability, Ferric Hydroxide
This study showed the influence of five process variables on the filterability of ferric hydroxide
precipitate. These parameters included: final pH; type of base used to precipitate the iron;
rate of base addition; rate of sample agitation; and the iron concentration. Surface charge
of the ferric hydroxide suspension was measured using a streaming potential technique. The
surface charge was correlated with filtration rates. The apparatus and filtering method were
described. Illustrations are provided of the streaming potential cell and apparatus, and
the filtration equipment. The rate of base addition and sample agitation had negligible
effect on the filtration time except when Ca(OH)2 was used as the precipitating base. Optimum
pH range was 6.5-7.5 with NaOH and KOH as the best precipitating bases. High iron concentrations
improved filterability.
Campion, H.T., "Lime Sludge and Its Disposal", Journal AWWA. Vol. 26, No. 4, pp. 488-494,
April 1934.
Key Words: Sludge treatment, Lime sludge, Disposal methods
The build-up of sludge deposits resulted from intermittent dumping of lime sludge to the Grand
River. Complaints on river pollution were received. Continuous sludge removal equipment for waste
dilution was expensive. Five hundred tons' of sludge could be handled at the sewage treatment
plant at extra cost. Plant modifications accompanied new sludge removal equipment. Disposal
methods proposed included: transport to fill or ponding reclamation; partial or complete
drying for use as soil sweetener; calcining and reuse; and use in paints, putty, wall board,
etc. Sludge beds could reduce moisture to 50%. Automatic vacuum filtration was relatively
inexpensive and could reduce moisture to 60%. Final drying could be accomplished in a rotary
drier or Nichols Herreschoff furnace. Farm use of dried lime is possible. A laboratory
calcining test was run. After 5 burnings and recycling of calcined lime, magnesium content
increased. Lime purity was below local specifications. Some success was reported in using
dried lime for plaster and insulating board manufacture. The final plan was to locally dry
and bag sufficient sludge and compete with limestone now used. Demonstrations would be
arranged and the product advertised.
Howson, L.R., "Lagoon Disposal of Lime Sludge", Journal AV1WA. Vol. 53, No. 9, pp. 1169-1173,
September 1961.
Key Words: Lagoons, Lime sludge
This study evaluated variables to be considered in the design of lime sludge lagoons. One
case showed that lime sludge discharged to a sewage treatment plant accumulated in the Imhoff
tanks, affecting plant efficiency and capacity to handle sewage wastes. Softening wastes
vary in character and density. Volume is inversely proportional to the solids concentration.
Lagoon storage capacity is influenced by: sludge volume, continuous or intermittant operation,
supernatant decantation, and air drying. Cost data is presented for pumping lime sludge in
asbestos-lined cement pipe. Pumping sludge to lagoons is an economical treatment where land
is available. A 50% moisture content can be achieved in well operated multiple lagoons with
decantation facilities and air drying. Sludge volumes can be reduced to 16% of original
volume. A loading rate of 0.5-1.0 acre-ft/yr/mgd/lOOppm hardness removed is suggested to
reach a 50% moisture content in one year. Multiple lagoons, at least three, must be operated
on a fill and let dry basis with filling at one end and decantation at the other. The water
level should be low to facilitate sludge compaction.
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Judkins, J.F. & Wynne, R.H., "Crystal-Seed Conditioning of Lime-Softening Sludge", Journal
AWWA. Vol. 64, No. 5, pp. 306-309, May 1972.
Key Words: Water treatment, Filterability, Settleability, Crystal-seeding
This report determined the filterability of sludge produced by softening laboratory-hardened
water and investigated the effect of crystal-seeding on the Settleability and filterability
of this sludge. The methodologies of synthesizing the hard water and performing jar tests
and Settleability and filterability evaluations are described. Important variables are:
crystal-seed dosage; mixing rate; and return-sludge recycle. Sludge filterability was
measured by the specific resistance and Settleability was made by the sludge volume index. A
200 rpm mixing rate was optimum in reducing specific resistance and a 300 rpm rate optimum
in reducing the sludge volume index. A 50% return-sludge dosage improved filterability while
a 25% return was best for improving Settleability. Recycling was beneficial. The sludge
produced ranged from 4.38-41.9 x 1010 m/kg in specific resistance.
Spaulding, C.H., "Conditioning of Water Softening Precipitates", Journal AWWA, Vol. 29,
No. 11, pp. 1697-1707, November 1937.
Key Words: Water softening, Conditioning
This study showed a process modification to conventional coagulation that could reduce floe
carryover to the filters. A softening precipitator was constructed to produce soft water and
agglomerate small particles into larger coagulated masses that are more easily filterable.
Experience with sludge return showed tastes and odors were imparted and a fine hard to remove
turbidity resulted. Laboratory and plant scale precipitator mixing and settling equipment are
described. Plant tests were run on modified and conventional units. The precipitator was
ten times more efficient than the conventional basin. Formulae developed for precipitator
diameter and height were modified to meet excessive depth limitations. This reactor is new
in that it supports precipitates in the settling compartment by means of vertical velocities.
The precipitator sludge is concentrated to 5-15% in thickeners and supernatant water is returned
to the raw water well. Physical and chemical data are presented for 6 months operation.
Water from the precipitators to the filters is generally less than 1 ppm turbidity and is
filtered rapidly.
Adrian, D.D. & Nebiker, J.H., "Source Control of Water Treatment Waste Solids". Progress
Report for Federal Water Pollution Control Administration, WP-01239-02, 95 pp., March 1969.
Key Words: Dewatering, Sludge treatment, Drying beds
The purpose of this report was the development of rational design formulations for engineers
to design dewatering and drying beds for water treatment sludges. Work is prepared on dewatering
by freeze-thaw and filter pressing procedures. Differential equations for the reaction
kinetics of sludge drying are prepared. Curves included: drying rate, weight, and free
moisture content versus time; evaporation ratio versus moisture content; drying rate versus
moisture content; critical moisture content versus drying solids per area; free moisture
content versus time; and log drying rate versus log free moisture content for alum sludges.
A mathematical model for drying and gravity drainage is constructed with initial and boundary
conditions. Curves of applied depth versus duration and total annual costs versus applied
depth are shown for different specific sludge resistances. An objective function is made
to optimize dewatering costs. Specific resistance and coefficient of compressibility are
studied for freeze-thaw tests. Concentrated sludge cakes frozen and thawed showed a cake
structure breakdown to a watery nature with crystalline solids that settle readily. An
appendix provided definitions of wastewater treatment sludge disposal terms.
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Barnhill, K.G., "Sludge Disposal Alternative", 31st International Water Conference of the
Engineers Society of Western Pennsylvania, October 27-29, 1970.
Key Words: Sludge, Equipment, Costs
As more primary and secondary wastewater treatment plants are built, more sludge will be
generated, and there will be more pressure to find an optimum disposal method. The optimiza-
tion would of necessity consider: (1) Availability of prior applicable experience, both in
reference to quantity and to type of sludge. (2) Equipment operation, degree of complexity,
need for standby units, dependability, manpower requirements, operator skill required, controls,
and hazards. (3) Costs, including capital, operating, and associated allied costs (hauling and
ash disposal). (4) Implementation problems, including air pollution, odors, ash disposal,
pretreatment (degree of dewatering), need for auxiliary fuels, other environmental effects.
(5) Regulatory and user attitudes, including present and future air and water pollution
requirements and directions.
Burd, R.S., "23. Water Plant Sludge Disposal. A Study of Sludge Handling and Disposal",
FWPCA Contract No. PH 86-66-32, pp. 476-485, June 1966.
Key Words: Sludge treatment, Purification wastes, Softening wastes
Treatment of water utility wastes has become important due to urbanization, unavailability
of cheap land, and public awareness of pollution. Purification sludge is mostly inorganic
with few odors. Softening wastes are principally calcium carbonate with small ferric,
magnesium, and aluminum hydroxide precipitates. 2.5 Ibs. of dry sludge is produced per
pound of commercial CaO. Solids concentrations vary from 5-33% with total volume 0.4-6%
of total water treated. Dilution of waste into rivers produces turbidity and forms sludge
banks. Lagoon capacities are effected by sludge solids concentrations, continuous or
intermittent loading, supernatant decantation, and climate. Costs are given for pipeline
transport to lagoons and for lime calcining processes. Sand drying beds and vacuum filters
are useful. Dried sludge has been used for soil conditioning and roadway base stabilization.
Alum recovery and lime recovery are suggested solutions to alleviating the magnitude of the
sludge disposal problem.
Doe, P.W., "Wate.r Plant Sludge Treatment", Paper Presented at Ohio Water Pollution Control
Conference, Sheraton Hotel, Columbus, June 29-July 1, 1971.
Key Words: Dewatering, Water plant sludge treatment, Artificial freezing, Filter pressing
Wastes from water treatment facilities vary in composition with the quality of the supply
source. Wastes from coagulation, flocculation, sedimentation, and filter backwashing processes
are affected by flow and seasonal changes. Sludge characterization of wastes generated from
reservoir, river, and groundwater supplies is provided. The advantages and disadvantages of
dewatering by pre-thickening, lagooning, artificial and natural freezing, vacuum-filtration
and filter pressing are presented. The AWWA Research Foundation is mentioned as a central
clearing-house for new or improved sludge treatment technology. Reference is made to the
artificial freezing of alum sludge at the Hodder Works. Polymer is fed to condition the waste
before thickening. Thickened sludge is stored and transported to freezing molds. The thawed
sludge is pumped to lagoons for liquid-solid separation. Cost, power, and construction
considerations are provided. The Little Falls Plant plans to filter alum sludge from sedimenta-
tion basins and filter backwashing. Laboratory and pilot tests were conducted to evaluate
design parameters. The presses utilize a precoat, lime, and polymers for conditioning. Two
presses can produce 50 tons of cake per 8 hour operation. The cake can be used as landfill.
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King, P.H., Bugg, H.M., Olver, J.W. & Argo, D.G., "Treatment of Waste Sludges from Water
Purification Plants", Bulletin 52 of the Virginia Polytechnic Institute and State University,
Blacksburg, Water Resources Research Center, Sept. 1972 49 pp., 19 fig, 3 tab, 18 ref.
Key Words: Sludge disposal, Water purification, Water treatment, Sludge treatment
The freezing and thawing process, as well as polyelectrolyte conditioning agents, rapidly
dewatered alum and ferric sludges collected from two water plants and lime sludges from two
wastewater treatment plants in Virginia. Sludge filterability and drainability were evaluated
by means of a Buchner funnel apparatus and the concomitant specific resistance tests which
enabled the determination of the correct pH, time of agitation, and effects of temperature
and solids concentration on the optimum dosage of polyelectrolytes. Selection of an appropriate
polymer was related to a number of factors, including primary coagulant and system pH. Optimum
dosage of the 6 anionic, 4 cationic, and 5 nonionic polyelectrolytes tested (products of 4
manufacturers) was directly related to sludge solids concentration. Dewatering of polymer
conditioned sludges was accomplished by "bench-scale sand beds and vacuum filtration. Although
alum sludge was relatively more difficult to dewater than sludge produced by iron salts,
polymer conditioning of alum sludge improved and diminished this difference. Anionic polymers
were effective conditioning agents for lime clarification sludges, and also proved somewhat
superior to nonionic agents and significantly better than cationic chemicals for alum and
ferric salt sludges.
Wertz C.F., "Sludge Removal and Disposal", International Water Supply Congress & Exhibition,
Stockholm, Sweden,'1964, 14 pp.
Key Words: Sludge disposal, Disposal methods
This report reviewed water treatment plant sludge disposal methods and referenced each
technique to individual water utilities. Purification and softening waste characteristics
are discussed. Sludge production is related to the physical character of the solid material
and the present solids in the wet sludge. Pilot testing on raw water 'is recommended to
determine the amount and type of sludge for lagooning or recalcining. The 48 State Sanitary
Engineers were surveyed. They reported disposal by discharge to watercourses, lagooning,
Chickening, recalcining, and alum recovery. Data are provided at different facilities for
each operation. Magnesium hydroxide can be eliminated from softening waste prior to calcining
by carbonation or selective softening procedures. The report concluded: discharges to water-
courses would be discontinued; lagoons and drying beds require careful design; supernatant
must be withdrawn from lagoons; and a method to separate turbidity from CaCO, sludge must be
developed before some utilities can recalcine.
*****
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WATER TREATMENT PLANT WASTES
Treatment of Sludges
Miscellaneous Processes
Davis, Stewart; "Alternatives For Phosphate Removal". Water & Sewage Works. Vol. 117, p. 336,
October 1970.
Key Words: Water quality control, Tube settlers, Mixed-media filter
Micro FLOG has developed a tertiary treatment process that can effectively remove orthophosphates
and polyphosphates by chemical precipitation. Domestic wastewater phosphorus has'been reduced
to 0.5mg/l P using lime dosages of 200 to 500 mg/1 CaO or alum dosages of 90 to 200 mg/1. The
process combines flocculation, modular tube settlers, and mixed media filtration. Units range
in size from 20 gpm to 200 gpm. Four 200 gpm units, requiring less detention time than conven-
tional treatment systems, are being planned for Ocean Pines, Maryland. A-Micro FLOC installa-
tion at Shagawa Lake has reduced effluent from 5.6 mg/1 to 0.05 mg/1 (P04 as P) using 145 mg/1
alum. Similar advanced treatment processes as Battelle Northwest's 100,00 gpd trailer mounted
system and a 280,000 gpd at Taulatin, Oregon are mentioned. A reference is also made to Lake
Tahoe's lime coagulation system and recalcination operation.
Haywood, R.W., "Basic Data for Chemical Waste Disposal", Sewage and Industrial Waste. Vol. 30,
No. 9, pp. 1156-1159, September 1958.
Key Words: Basic data collections, Chemical wastes, Waste characteristics
The purpose of this paper was .to discuss benefits derived from early recognition and study of
waste disposal problems and describe difficulties in obtaining basic data for evaluating
disposal requirements. No generalizations are usually possible for highly variable, complex,
organic-inorganic chemical wastes. Control may be achieved through product substitution or
process modification. Product substitution examples lowering treatment requirements include:
plastic for starch in the textile industry: mineral acid for organic acid; and process
applications producing a filterable insoluble salt rather than highly soluble one. A systems
approach should be applied to processes to minimize the cost of production plus waste treat-
ment. Several physical-chemical waste characteristics are enumerated. Testing complications
for BOD analysis and seed preparation are detailed. Adequacy of testing laboratories must
be considered. Toxicological studies should include fish kill effects and food chain destruc-
tion. The size or volume, type (flowing, impounded, tidal), and present and future use of
receiving waters are important. For adequate dilution, the shape, quantity, velocity, turbulence,
salinity, and thermal stratification of watercourses need study.
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Mogelniki, S.J., "Experiences in Polymer Applications to Several Solids-Liquids Separation
Processes", Proceedings Tenth Annual Sanitary Engineering Conference, Waste Disposal from
Water and Wastewater Treatment Processes, University of Illinois, Urbana, pp. 47-62,
February 6-7 , 1968.
Key Words: Polymers, Dewatering, Primary flocculants, Flocculant aids, Filter aids,
Sludge aids, Sludge conditioning
This paper cited the early utility of polymers in the mining, metal, and paper Industries
and tabulated data on the effectiveness of synthetic, organic, high molecular weight, water
soluble polymers to separate solids in industry. The polymers depend on adsorption, charge
neutralization, and inter-particle bridging to agglomerate small colloidal suspensions into
larger colonies. Typical cationic poLyamine, anionic, and nonionic polymer formulae are
prepared. Polymers function as primary flocculants, floeculant aids, filter aids, and sludge
conditioning agents. Data are tabulated for polymer application in sedimentation, flotation,
filtration, and centrifugation processes. Wastewater clarification with polymer addition is
shown on aluminum industry effluent, steel mill flue dust, electroplating streams, tannery
waste, steel mill scale, and raw sewage flocculation at an activated sludge and trickling
filter plant. Flotation data are prepared for brewery, vegetable oil processing, meat
packing, waste activated sludge and petroleum refinery wastes. Data are presented for sand
bed drying and vacuum filtration of textile industry, elutriated digested primary, and
primary-secondary elutriated digested wastes. Centrifugation studies were conducted on
chemical and sewage sludges. Polymer advantages include: reduced handling and chemical
storage; easily controlled dose levels; increased suspended solids capture; higher hydraulic
capacity; and reduced costs.
Hemerow, N.L., "Cooperative Treatment of Industrial Wastes", Industrial Water Engineering,
Vol. 6, No. 6, pp. 30-32, June 1969.
Key Words: Industrial wastes, Municipal wastes, Separate treatment, Combined treatment
This article proposed the consideration of several art and science factors for joint treat-
ment of combined industrial and municipal wastes. The art factors included: precedent of
separate or combined treatmentjrelation of industry to community; political compatability
of industrial and municipal officials; sewer charge rates; industrial proximity to sewage
treatment plant; competence of sewage treatment personnel to handle the waste and avoid
major upsets; and the permanence of industrial waste production in type and quantity. The
science factors included: the type of sewage plant and its ability to remove the industrial
contaminants; the industrial waste character and parameters such as k value, deoxygenation
rate, ultimate oxygen demand, toxic chemicals and metals, temperature, grease content,
refactory organic matter, phosphates, nitrates, and other algal nutrients; industrial effluent
quality and effect on quality of receiving stream; and the economic alternatives available.
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DISPOSAL METHODS
Brine Wastes
Day, M.E., et al, "Brine Disposal Pond Material", Research and Development Progress Report
No. 588, Contract No. 14-01-0001-1306, Work Order No. 3, August 1970. 134 pp.
Brine disposal, Ponds, Design considerations, Cost estimates
This report is designed to present new information on the disposal of brines from saline water
conversion processes and the associated costs. Information is presented on: design considera-
tions for disposal ponds; design criteria and cost estimates; operation and maintenance con-
siderations and costs; methods to control seepage of concentrated brine solutions .into
aquifers; construction of various holding ponds; and detailed specifications for earthwork,
buried linings, hard-surface linings, and earth linings. Appendices include material on:
summary of state regulations on brine disposal; bibliography; computer analysis of brine
disposal ponds; glossary; and conversion factors for British to metric units of measure
Haney, P.O., "Brine Disposal from Sodium Zeolite Softeners", Journal AWWA. Vol. 39, No. 12,
pp. 1215-1219, December 1947.
Key Words: Brine disposal, Sodium zeolite softeners, Controlled dilution
the waste from sodium zeolite softeners contains waste products of regeneration plus unused
salt. The brine is principally composed of chlorides of calcium and magnesium, together
with small amounts of various iron and manganese compounds. Usually 5-10% of the treated
water is needed for regeneration. Salt requirements are 0.4-0.5 pounds/1000 grains hardness
removed. Limiting USPHS potable water standards are: magnesium 4.125 ppm; chloride ^ 250 ppm;
and total solids^ 1000 ppm tolerable. Brine discharges to sanitary sewers can corrode
pumping equipment, force mains, and upset biological processes. Discharge to streams can
kill fish and injure livestock. Evaporation ponds sometimes barely exceed rainfall rates,
leave salt residues, and contaminate groundwater or streams by seepage. Controlled dilution
requires storage reservoir and release mechanism costs. Brine disposal veils may require
pretreatment to prevent suspended matter from plugging the pores of the receiving formation.
Costs/foot of well are outlined. Brine must be conditioned not to react with receiving
formation matter to produce precipitation. Controlled dilution appears most applicable.
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DISPOSAL METHODS
Subsurface
AWWA Committee, "Findings and Recommendations on Underground Waste Disposal", Journal AWWA,
Vol. 45, No. 12, pp. 1295-1297, December 1953.
Key Words: Water pollution, Industrial waste disposal
Ibis article enumerated considerations for industrial waste disposal on underground sources.
Findings include: nationwide scope of 'industrial groundwater pollution; waste types as
natural-artificial brines, phenolic compounds, heavy metal salts, cleaning fluids, picric
acid, gasoline-petroleum products, pickling liquors, fruit and vegetable cannery wastes,
milk wheys, and cooling water; pollutant flow is smooth and laminar with velocities of
inches or feet/day; hydraulic gradients influence route and flow times; industrial water
requirements are growing; groundwater disposal is attractive; and some wastes are toxic.
Conclusions show geologists must appraise aquifer contamination, preventive pollution measures
are needed, legal considerations are required, and groundwater will provide future needs.
The report recommends: identification of areas where groundwater disposal is not possible;
permit systems for agencies to control industrial wastes; and provisions for recourse to
courts, if needed, to end industrial underground waste disposal.
AWWA Committee, "Underground Disposal and Control", Journal AWWA. Vol. 49, No. 10, pp. 1334-1342,
November 1957.
Key Words: Waste disposal, Underground pollution
This article cites examples of underground pollution problems and presents survey analysis
of U.S. underground disposal practices. These examples include: well screen corrosion due
to acid waste percolation in an estuarine swamp; cadmium and hexavalent chromium contamination
of groundwater by aircraft waste discharged to leaching pits; and calcium chloride contamina-
tion of downstream wells by surface discharge of this concentrated waste. Survey information
is provided on contaminant types, waste constituents, waste sources, and statutory control in the
U.S. A tabulation is made of the nature of specific pollutants and observed distance and time
of travel. A recommendation is made to group states with similar control characteristics for
common studies of existing problems and determination of trends. Factors to estimate potential
groundwater pollution are: gaging of industrial growth rate-adequacy of existent waste facilities
and future needs; urban or suburban expansion developments to provide industrial growth;
available water sources and comparative use of waters; general geologic and hydrologic conditions
governing underground contaminant movement; and knowledge of existing statutory controls.
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AWWA Committee, "Underground Waste Disposal and Ground Water Contamination", Journal AHWA
Vol. 52, No. 5, pp. 619-622, May 1960. *
Key Words: Water quality, Subsurface discnarge
Thia article considers the development of quality parameters to detect ground water contamination.
Suitable trace constituent selection is complex. Difficulties arise since: the elements must
be in natural water-soluble compounds; concentration determination must be simple and inexpen-
sive; the elements must be common in most natural groundwaters and in the probable liquid-waste
contaminant; and the elemental compounds must be stable. The amortization cost of industrial
surface waste disposal over plant life usually indicates a savings over most injection or subsur-
face discharge techniques. Rigid statutory standards are needed for disposal well construction
and ground formation selection. Pretreatment may be required. Ground-surface disposal is
generally by ponding and spraying or ditch-spreading application to large land areas. Ground-
surface disposal contaminates when the waste application rate is in excess,of evaporation-
transpiration requirements of vegetal cover. Synthetic detergent flow times are a function of
distance, pumping rate, and area geology. Standards need development to evaluate disposal tech-
niques and detect unsatisfactory disposal practices.
Billings, N., "Ground-Water Pollution in Michigan", Sewage and Industrial Wastes. Vol. 22,
No. 12,'pp. 1596-1600, December 1950.
Key Words: Groundwater, Waste disposal, Flow direction, Waste toxicity, Time response
This report provided some considerations on the effect of pollutant infiltration into ground-
water reservoirs. Where groundwater recharge is important, waste penetration into the soil may
be harmful. Examples of time responses for contaminated groundwaters are prepared for plating,
picric, acid, phenolic, salt, gasoline, cheese factory, and septic dry well wastes. Subsurface
flows are difficult to predict. Infuencing factors include: hydraulic gradient; high-capacity
water wells; drainage ditches; local cloudbursts; and dam construction. Major considerations
with waste disposal on the ground are enumerated. They are: waste toxicity; soil conditions
and geology; effect of waste on groundwater; and flow direction of waste. Pumping tests
provide some criteria and help establish liability in cases of well contamination. Legal
restrictions are being formulated to consider waste disposal effect on underground resources
endangering a neighbor's welfare. Close .regulation is needed to conserve water resources for
this and future generations.
Black, W.B., "Underground Waste Disposal", Sewage and Industrial Waste, Vol. 30, No. 5, pp. 669-
672, May 1950.
Key Words: Deep wells, Industrial wastes, Rock strata
This paper discussed the injection of industrial wastes into deep wells. Porous sandstone
formations in Michigan are satisfactory for industrial waste disposal. States have allowed oil
refineries, chemical plants, and pharmaceutical plants to use these strata for pumping inorganic
and organic industrial wastes. Rock strata testing is urged to measure waste control, prevent
contamination of fresh water, and study effect on surroundings. Testing steps include: Fact-
finding study of the industrial plant waste; study of underground formation; laboratory compat-
ibility of reaction between waste and receiving strata; drilling of test wells to determine
possible reservoirs and barrier effectiveness; and capacity, injection rate, and flow character
of wastes. These data give daily capacity, pump pressures needed, extent of waste travel, and
safety factors. Systems economics, construction cost, daily maintenance, and depreciation cost
can be estimated. Fracturing techniques give an estimated 40 million gallon/acre total storage
capacity. Cost data are given. Potential underground uses are: radioactive wastes; municipal
sewage effluent; and fresh water storage.
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Caswell, C.A., "Underground Waste Disposal: Concepts and Misconceptions", Environmental
Science & Technology. Vol. 4, No. 8, pp. 642-647, August 1970.
Underground storage, Underground waste disposal
This article illustrates overall aspects of subsurface disposal considerations. Advantages
of underground disposal include: ultimate disposal of untreatable wastes from immediate
environment: salt water barrier created; storage in arid areas; groundwater recharge; solids
storage and disposal; and potential air pollutant storage. Disadvantages include: presence
of unfavorable receivable formations; fluid incompatability; loss of waste control; and legal
liability. Surface and sub-surface factors of well design are described. A hypothetical
migration rate of fluid example is given. Fluid flow is affected by; permeability; pore
geometry; bottom hole pressure; hydrologic conditions; saturation percentage; and damage to
formation face. Misconceptions in water injection and salt water disposal wells are
explained. Mechanical factors in fluifl migration include: formation cementation and porosity;
lateral effective permeability and porosity; overlying and underlying beds; fault presence'
of fracture patterns; earthquake occurrence; fresh-salt water contact levels; structural
attitude and hydrologic character of injection formation; and casing effectiveness and
cementing program.
Cleary, E.J., and Warner, D.L., "Some Considerations in Underground Wastewater Disposal",
Journal AWWA. Vol. 62, No. 8, pp. 489-498, August 1970
Key Words: Deep well pumping, Underground injection
This study outlined public policy, legislative and legal aspects, and administrative guidelines
and evaluation criteria for deep well injection of liquid wastes. Industrial wastes being
injected include: alkalies, acids, chromates, nitrates, phosphates, sulfites, alcohols, ketones,
phenols, cyanides, chlorinated hydrocarbons, and radioactive materials. A national registry
could collect and disseminate useful data on underground strata for various wastewaters and
provide an expanding body of experience. The effects of long term waste storage, degradation
of potential underground resources, and ability of agencies to evaluate injection proposals
require study. Case histories are given, Specific legislation exists in Ohio, West Virginia,
and Texas. Ohio and West Virginia regulations are discussed with New York policy. A newly
created government agency might name suitable injection zones and maintain quantity and
quality physical-chemical waste injection data. Legal liabilities and constraints are dis-
cussed. Decisions and requirements will be ultimately based on: wastewater characteristics;
geology and subsurface hydrology; well construction and testing methods; surface and standby
facilities, construction materials; operational practices; and abandonment procedures. The
ORSANXX) commissioners should create an ad hoc committee to develop public policy guidelines,
regulatory procedures, and evaluation criteria for underground injection.
Grubbs, D.M., Haynes, C.D., and Tucker, W.E., "Conservation of Fresh-Water Resources by Deep-
Well Disposal of Liquid Wastes", Publication Partially Funded by OWRR, USDI, under Water
Resources Research Act of 1964, 85 pps., 1970.
Key Words: Liquid wastes, Deep-well disposal, Subsurface disposal
This study reported that under controlled conditions deep-well injection of liquid wastes
can be accomplished in some of Alabama's geologic formations without contaminating fresh-
water supplies. Legal implication of this disposal require further definition. General
physical parameters explored included subsurface disposal history, geologic requirements,
porosity and permeability criteria, ground water fluids, sedimentary rock type and geometry,
evaporites, reservoirs, and confining rocks. Fluid'mechanics, reservoir mechanics, and pressure
relationships are discussed. Specific sites in Alabama are studied and the feasibility of deep-
well disposal considered. An appendix contained cost and design data generated by a computer
program. Data include capital outlay, operating and maintenance costs. Another appendix
treated major chemical reactions between an acid industrial waste, the waters of the receiving
formation, and minerals in Alabama's salaquifers. Rock reservoirs are laboratory tested to
establish storage capacity, flow parameters, and compatibility of receptive layers with the
waste. A final appendix discussed stratigraphy and physiography of Alabama.
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Le Grand, "Role of Ground Water Contamination in Water Management", Journal AWWA, Vol. 59
No. 5, pp. 557-565, May 1967. ' *"
Key Words: Water Pollution, Quality deterioration
The purpose of this article is to place groundwater contamination and its complement in per-
spective with water development and demonstrate its importance in long-range integrated plans.
Geographically distinct areas include: urban area encompassing a municipality and beyond cen-
tralized water and sewer service, and rural areas with individual water-waste treatment units.
Ground water contamination is influenced by disposal practices; artificial recharge of aquifers,
accidents, and salt water intrusion. A major objective is to maintain good health practices
and minimize disposal costs. Variable factors for pollution are: variety of waste material;
wide toxicity range; man's disposal patterns and accidental releases; subsurface water develop-
ment; elemental behavior in soil, water, and rock environment; and spatial and temporal criteria.
Balanced surface and groundwater development and waste disposal policies are needed with a broad
understanding. Other considerations, and land and stream classifications are outlined. An in-
ventory should be compiled of type and quantity of groundwater contaminants and behavior. Work
must be coordinated with specific elemental effect on biota studied.
McLean, D.D., "Subsurface Disposal: Precautionary Measures", Industrial Water Engineering.
Vol. 6, No. 8, pp. 20-22, August 1969.
ReyWords: Injection wells, Subsurface disposal
This study reviewed the characteristics of sedimentary rock receiving formations of liquid
wastes, and equations developed by the petroleum industry to measure important disposal well
parameters. Desirable characteristics included: uniform sandstone, limestone, dolomite, or
fractured shale, large areal extent; sufficient thickness; high porosity and permeability;
adequate overlaying and underlaying of impermeable strata or aquicludes; low pressure; below
and separated from fresh water horizons; salt - water filled formation; artesian in nature;
strata compatible with injected fluids; and no unplugged wells can penetrate the formation
in the vicinity. The petroleum industry has developed predictive equations for injection rates
and pressures. However, testing is needed. The drilling and testing of disposal wells require:
protection of fresh water sources and minerals; injection tests; injection of wastes compatible
with receiving reservoir; and monitoring of injection pressure and rate, effluent chemical com-
position, annulus pressure, and injactivity index (input rate/bottom hole pressure). Further
research is required in hydrology waste chemistry, and efficient operation of subsurface disposal
systems. Present predictive equations are good when the aquifer is homogeneous and the reservoirs
unlimited.
Miller, S.M., "Injection Wells Pose a Potential Threat", Environmental Science & Technology.
Vol. 6, No. 2, pp. 120-122, February 1972.
Key Words: Injection, Deep-well disposal
The study presented technical and legislative criteria for the disposal of liquid waste by deep-
well injection. More than 200 industrial waste wells are in operation. No federal regulations
bind these operations and few states have considered this problem individually. The adequacy
of injection to solve fluid waste problems and the need for public, local, state, and federal
controls in questions. Subsurface areas can temporarily store reclamable fluids or permanently
store unreclamable material. Injection theories are oversimplified or complex. Predictive
mathematical equations are based on microscopic scale studies. EPA neither opposes nor promotes
deep-well injection. Wastes untreatable by alternate methods may be injected. Four states have
specific injection laws. Texas requires treatability studies, a list of adjacent landowners, and
a technical report to include geologic, waste, and well construction data. Specific effects of
well injection operations are enumerated. A series of earthquakes in Denver during the 1960's
were a function of well injection and time.
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Wright, J.L., 'Underground Waste Disposal", Industrial Water Engineering. Vol. 6, No. 5,
pp. 24-27, May 1969.
Key Words: Liquid wastes, Well disposal
The author stated deep well disposal of liquid waste is technically and economically effective
in areas with extensive porous rock formations and with allowable laws. Design requirements
included: waste confinement to geologic formation selected for disposal; knowledge of injectivity
and storage capacity of disposal zone; physical-chemical waste character analysis; and waste
compatability with the receiving formation. Acids, steel mill picking liquors, toxic organic
chemicals, caustics, brines, phenols, sulfides, chromates, cyanides, and radioactive materials
have been injected. Storage, treatment, filtration area, injection pumping, and monitoring
of liquid waste are essential. The underground formations of the Great Lake region, Mid-
Continent, 'and Gulf Coast areas are described. A tabulation of construction costs for disposal
veils is made based on pumping an equal volume of non-corrosive filtered waste into a 500
foot deep well. Installation and operating costs are tabulated. An economic economic
comparison is made of well disposal versus surface treatment systems.
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SECTION VIII
ACKNOWLEDGEMENTS
Research Foundation Staff
The AWWA Research Foundation Staff for conducting the project
"Information Resource on Water Pollution Control in the Water
Utility Industry", and for preparing this report was:
Harry A. Faber, Research Director
Anthony D. Nardozzi, Project Research Director
(Until July 15, 1972)
Michael J. Taras, Project Research Director
(From September 5, 1972)
Kitty C. Klomp, Administrative Assistant
Mary Manca, Secretary
Aida Said, Secretary
Committees Cooperating with the Research Foundation
AWWA Research Committee on Sludge Disposal
James C. Lamb, III (Chairman)
University of North Carolina, Chapel Hill, NC.
R.L. Gulp, So. Tahoe Pub. Util. Dist., Lake Tahoe, CA.
Robert B. Dean, Sanitary Eng. Center, Cincinnati, OH.
Richard I. Dick, Univ. of Illinois, Urbana, IL.
John W. Krasauskas, D.C. Filtration Plants, Washington, D.C.
Walter K. Neubauer, O'Brien and Gere, Syracuse, NY.
Lee Streicher, Metro. Water Dist. of So. Calif., LaVerne, CA.
Edwin C. Weber, Department of Water Resources, Annapolis, MD.
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AWWA Committee on Water Treatment Plant Wastes
Lee Stretcher (Chairman )
Metro. Water Dist. of So. Calif., LaVerne, CA
H. Benjes, Jr., Black and Veatch, Kansas City, MO
L.K. Cecil, Tucson, Ariz.
P.W. Doe, Havens & Emerson, Ltd., Paterson, NJ
C.D. Gates, Cornell University, Ithaca, NY
C.A. Jackson, Water Dist. No. 1 of Johnson County, Mission, KS
W.E. Katz, Ionics Inc., Watertown, MA
R.N. Kinman, Univ. of Cincinnati, Cincinnati, OH
D.A. Lazarchik, Div. of Indus. Wastes, Harrisburg, PA
P.F. Mahoney, Smith & Mahoney Cons. Engrs., Allbany, NY
H.L. Nielson, E. Bay Munic. Util. Dist., Oakland, CA
H.R. Peters, Atlanta Water Works, Atlanta, CA
J.R. Popalisky, Kansas City Water Dept., Kansas City, MO
P.L. Riley, P.L..Riley Co., Louisville, KY
W.B. Schworm, Sverdup & Parcel and Assoc., St. Louis, MO
J.C. Timen, Johns-Manville Corp., New York, NY
P ro j e c t Suppo rt
The support of this project by the Office of Research and Monitoring,
Environmental Protection Agency, and the assistance provided by Mr.
William J. Lacey, Chief, Applied Science and Technology, and Project
Officers Mr. James D. Gallup and Mr. Harry F. Smith, Jr., P.E., Chief,
Planning and Technical Services Section, is gratefully acknowledged.
*U.S. GOVERNMENT PRINTING OFFICE:1974 546-314/195 1-5 64
-------
SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
^^^MliVBV
Title
INFORMATION RESOURCE: FINAL REPORT
WATER POLLUTION CONTROL IN WATER UTILITIES
3. Accession No,
w
Author(s)
Faber, H.A. , Nardozzi, A.D. & Taras, M.J.
5. Organization
American Water Works Association Research Foundation
New York, New York
35, SupplementaTy Sfotes
Environmental Protection Agency, report number
EPA-660/2-73-020, December 1973.
10. Project No, S8Q0936
12120 EUR
II.' Contract/GrstitNo.
16. Abstract ^e goals of this effort were the collection, coordination, and communicatii
of information of a scientific, technical, and administrative nature relative to
control of pollution caused by wastes from water treatment plants, in accordance with
the recommendations of an industry advisory committee. It covers laboratory tests
underway or completed at widely dispersed water treatment plants throughout the country
on the applicability of polymers as primary coagulants, coagulant aids, and sludge
conditioning agents, with the objective of alleviating the problem of water treatment
plant waste disposal. Also included is the evaluation in cooperating laboratories of
analytical methods suitable for the physical and chemical examination of the sludge and
sludge solids from water treatment plants. A total of 121 abstracts of technical
articles were prepared on the varied aspects of water treatment plant waste disposal:
waste problems at 26 named water treatment plants or geographical locations, waste
treatment in the new water treatment plants, water conditioning practices,
characteristics of alum, iron, and softening wastes; treatment of filter washwater;
treatment of sludge by the reclamation of alum, lime, and magnesium carbonate, and by
dewatering processes involving centrifugation, drying beds, filter pressing, freezing,
and vacuum filtration; subsurface disposal and disposal of brine wastes.
11 a. Descriptors
*Sludge disposal, *Sludge treatment, *Abstracts, Water treatment, Water purification
in. Identifiers
*Information clearing-house, *Information resource, *Water utility sludge,
Information dissemination
17'.: COWRR Field & Group
18. AvzJl;
05D, 05E
Abstractor
Michael J. Taras
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. O. C. 2O24O
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American Water Works Association
WR.S'C 1O2 (RtV.JUNf
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Research Foundation
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