EPA-600/4-76-052
October 1976
Environmental Monitoring Series
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL MONITORING series.
This series describes research conducted to develop new or improved methods
and instrumentation for the identification and quantification of environmental
pollutants at the lowest conceivably significant concentrations. It also includes
studies to determine the ambient concentrations of pollutants in the environment
and/or the variance of pollutants as a function of time or meteorological factors.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600A-76-052
October 1976
DEVELOPMENT OF SUSPENDED SOLIDS QUALITY
CONTROL AND PERFORMANCE EVALUATION SAMPLES
by
Enos L. Stover
Peter J. Marks
Roy F. Weston, Inc.
West Chester, Pennsylvania 19380
Contract No. 68-03-2333
Project Officer
Edward L. Berg
Quality Assurance Branch
Environmental Monitoring and Support Laboratory
Cincinnati, Ohio 45268
ENVIRONMENTAL MONITORING AND SUPPORT LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Environmental Monitoring and
Support Laboratory-Cincinnati, U.S. Environmental Protection Agency, and
approved for publication. Mention of trade names or commercial products
does not constitute endorsement or recommendation for use.
i i
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FOREWORD
Environmental measurements are required to determine the quality of
ambient waters and the character of waste effluents. The Environmental
Monitoring and Support Laboratory-Cincinnati:
1. Develops and evaluates techniques to measure the presence
and concentration of physical, chemical, and radiological
pollutants in water, wastewater, bottom sediments, and
sol id waste.
2. Investigates methods for the concentration, recovery, and
identification of viruses, bacteria, and other microbiological
organisms in water. Conducts studies to determine the responses
of aquatic organisms to water quality.
3. Conducts an Agency~wide quality assurance program to assure
standardization and quality control of systems for monitoring
water and wastewater.
Commensurate with an Agency-wide quality assurance program, the
latest report on the development of synthetic suspended solids samples
contains the results of a feasibility study to determine compounds that
exhibit the optimum physical and chemical properties for production of
large number of samples. Consideration of such factors as solubility,
wettability, dispersion, flocculation, abrasion, biodegradabi1ity,
stability, and sub-sampling recovery resulted in the selection of
anthracite coal, Fuller's earth, and rayon fibers as solids materials
for suspended solids quality control samples. A total of 10,000
quality control samples, each consisting of one of three specified weights
of one of these three compounds, were packaged in individual containers.
Dwight G. Ballinger, Director
Environmental Monitoring and Support
Laboratory-C i nc i nnat i
i i i
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ABSTRACT
A two-phase study was conducted to develop a synthetic suspended solids
sample for use in quality control checks and performance evaluation in
environmental monitoring laboratories. The first phase consisted of a
feasibility study to determine compounds that exhibit the optimum physical
and chemical properties for synthetic suspended solids samples; the second
phase involved production of suspended solids samples in individual con-
tainers.
Compounds investigated that met all the design criteria included rayon
fibers and Fuller's earth. A total of 10,000 quality control samples
consisting of rayon fibers, Fuller's earth, and anthracite coal were pack-
aged for completion of the project. Anthracite coal was packaged to demon-
strate the variability shown by certain types of solids in the sub-sampling
step of the suspended solids test method.
This report was submitted in fulfillment of Contract Number 68-03-2333
by Roy F. Weston, Inc. under the sponsorship of the Office of Research and
Development, U.S. Environmental Protection Agency. Work was completed in
April, 1976.
IV
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CONTENTS
Foreword i I i
Abstract iv
Figures vi i
Tables viii
Acknowledgments ix
I . Introduction 1
Background 1
Objectives 2
Development Criteria . . • 2
I I. Conclusions 4
111. Recommendations 5
IV. Development and Feasibility Study - Phase I 6
Literature Survey 6
Scope and Methodology 6
Compounds Meeting Initial Design Criteria .... 7
Technical Approach 7
Statistical Treatment of Data 7
Analytical Method for Suspended Solids 13
Solubility Testing 13
Wettability and Dispersion Testing 18
Flocculation Testing 18
Abrasion Testing 19
Evaluation of Sub-Sampling 19
Mixing Technique 19
Recovery Tests (Analytical Method) 21
Selection of Compounds for Packaging 21
Biodegradabi1ity Testing 27
Stability Testing 27
Percent Recovery Tests on Mixture of
Fuller's Earth, Anthracite Coal, and
Rayon Fibers 29
V. Packaging of Compounds - Phase II 31
Preparation of Compounds for Packaging 31
Packaging Requirements 31
Number and Type of Samples 31
Packaging Technique 32
Instrument Packaging Precision 32
Quality Control 32
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CONTENTS
continued
VI. Discussion 3k
Statistical Evaluation of Data 34
Synthetic Suspended Solids Analysis 36
Preparation of Quality Assurance Samples
for Suspended Solids Analysis 36
Analytical Method for Quality Assurance
Suspended Solids (Non-Filterable Residue) . . . .36
VII. References 38
VI
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FIGURES
Number Page
1 Percent Recovery Versus Particle Size for Fuller's Earth 25
2 Standard Deviations of Analytical Method Versus
Concentration 35
VI I
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TABLES
Number Page
— -3
1 Compounds Meeting Specific Gravity and Solubility
Requirements 8
2 Compounds Selected for the Initial Developmental
Investigations 11
3 Compounds Failing Initial Developmental Tests Ik
k Compounds Passing Initial Developmental Tests 15
5 Percent Recovery Tests for Compounds Passing the Initial
Screening Tests (250 mg/1) at 6 Repetitions 16
6 Percent Recovery Tests for Compounds Passing the Initial
Screening Tests (25 mg/1) at 6 Repetitions 17
7 Abrasion Testing Results 20
8 Evaluation of Mixing Techniques Using One-Liter Volumetric
Flasks (Vigorous Shaking and Mixing with Magnetic
Stirring Bars) 250 mg/1 22
9 Mixing Test Results (Shake & Pour) with Graduated Cylinder . . . 2k
10 Results of Biodegradability Tests (Five-Day BOD Tests) 28
11 Compound Mixing Tests Results 30
VI I I
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ACKNOWLEDGEMENTS
The support of this effort by the Environmental Monitoring and Support
Laboratory, Office of Research and Development, Cincinnati, Ohio (especially
Mr. Edward L. Berg, Project Officer, and the other manuscript reviewers) is
acknowledged with gratitude.
IX
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SECTION I
INTRODUCTION
The success of the environmental protection efforts to a large degree
rests on the reliability of the information provided by the data collection
activities. Quality control and performance evaluation samples become a
requirement to insure confidence in the precision and accuracy of selected
methods used by participating laboratories; an evaluation of the results
provides a sound basis for judgment of the relative capabilities of those
laboratories performing the analyses. The Environmental Monitoring Support
Laboratory has prepared various water quality parameters as a quality control
service to laboratories and analysts.
To date, no water quality control sample for measuring suspended solids
has been developed to assist in gathering water quality data, to aid in
determining compliance with established environmental standards, or to aid
in the determination of the effectiveness of pollution abatement methods and
procedures. A research effort and a feasibility study were required to
determine the optimum physical and chemical properties for such a synthetic
suspended solid or series of suspended solid samples for use in quality con-
trol checks and performance evaluation in environmental monitoring labora-
tories, because information pertaining to this subject was not available.
BACKGROUND
Industrial and municipal effluents contain suspended solids that vary
widely in both physical and chemical composition, including size and specific
gravity. Information on solids characteristics has not been researched to
an appreciable degree, especially for the various types of industrial waste-
watsrs.
Ths results of a literature review conducted to characterize sanitary
sewage, combined sewer overflows, and stormwater runoff in terms of their
suspended solids content and physical and chemical characteristics were
reported by Beak Consultants Limited of Rexdale, Ontario, Canada. These
results indicated that these wastewaters could not be characterized by single
average concentrations of suspended solids or by a single particle size
distribution. A wide range of individual chemical and physical parameters
would be required to characterize the suspended solids contained in sanitary
sewage, combined sewer overflows, and stormwater runoff.
The solids properties of sanitary sewage are influenced by factors such
as range of flow rate, time of day, and contribution of industrial waste-
waters to the total flow. Industrial wastewaters can add suspended solids
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with a variety of particle sizes, specific gravities, and chemical charac-
teristics, depending on the types of wastewaters added. In addition to
those solids normally found in sanitary sewage, combined sewer overflows
contain solids washed into the sewer systems from land areas and roadways.
There also is wide variation in the solids characteristics of separate
stormwater runoff, because of land use and varying soil and topographical
features.
The characteristics of the grit in wastewater depend on many factors,
including: soil; type of ground cover; urban street conditions; age and
condition of the sewer pipe and its joints, pipe slope, and catch basins;
street cleaning practices; and whether the collection system consists of
separate or combined sewers. Available data from existing wastewater treat-
ment plants concerning grit removed were compared to establish criteria for
grit character izat ion.2,3 ,** Based on these data, a "typical grit" for the
purpose of investigation ranges in size from 0.2 millimeter (mm) to 2.0
millimeter, with a gradation corresponding to a straight line on a mechanical
analysis graph. The specific gravity of the typical grit is assumed to be
2.65. Normal grit concentrations in sewage have been defined as those
between 20 and 360 milligrams per liter (mg/l).^
Both the velocity and the concentration of suspended solids in sewers
vary with position in the sewer cross-sect ion.5 Suspended solids heavier
than water have their lowest concentration near the surface, and the concen-
tration increases with depth below the surface. Suspended solids lighter
than water float on the surface of the water. The manner in which the veloc-
ity is distributed in the sewer section will affect the distribution of the
suspended solids in the flowing water. Therefore, the distribution of
suspended solids in the sewer may affect the accuracy of the suspended
solids results because of inadequacies in the sample collection or in the
methods themselves. However, evaluation of the effects of sampling equipment
and sampling procedures on the determination of suspended solids in water
and wastewater streams is beyond the scope of this project for the develop-
ment and packaging of quality control samples of synthetic suspended solids.
OBJECTIVES
The overall objectives of this two-phase contract were: 1) the develop-
ment of a synthetic suspended solids sample(s) for use as quality control and
performance evaluation samples (Phase l); and 2) production and delivery to
the U.S. Environmental Protection Agency (EPA) of 10,000 containers (vials)
of suspended solids samples (Phase II). This report presents the results of
the development program and feasibility study, along with the packaging in-
formation and requirements.
DEVELOPMENT CRITERIA
The synthetic suspended solid samples selected from the research effort should
be representative of the types of suspended solids in industrial and municipal
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wastewaters. The suspended solids present in these types of wastewaters can
generally be characterized as falling within the following specific gravity
and particle size ranges:
Specific Gravity - 0.8 to 2.65
Particle Size - 0.01 to k.S mm
The following design criteria were established for consideration during the
feasibility study for the development of the synthetic suspended solids:
1. The weight of synthetic material shall not change during the
analytical procedure. Therefore, the material shall be non-
volatile and shall not have any other property which will
adversely affect the weight during any step of the analytical
procedure.
2. Based upon the standard glass fiber filter, 100 percent of the
solids should be retained on the filter.
3. The synthetic solids material shall be relatively non-hygroscopic
and non-clinging to the sides of the container.
k. The synthetic solids shall be non-flocculating, thereby providing
the flexibility to mix several homogenous materials to produce a
heterogeneous synthetic solids sample containing fractions of
varying size and with varying specific gravities. In addition,
the charge on the solid particles shall be delineated. The
synthetic solid must be easily wettable and dispersable in water.
5. The synthetic solid samples shall remain constant in weight and
character over a long period of time. As such, the solids shall be:
a. Non-biodegradable
b. Non-adsorbent
c. Insoluble in water
6. The synthetic suspended solids shall have high abrasion and impact
resistance, to minimize breaking up into smaller particles which
would subsequently affect the percent retention on the fiber-glass
filter.
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SECTION II
CONCLUSIONS
1. During the research investigation, Fuller's earth and rayon fibers were
found to be acceptable compounds for packaging as synthetic suspended
solids quality control and performance evaluation samples.
2. The precision and accuracy obtainable in the suspended solids test
depend within certain limits on the specific gravity and particle size
of the suspended solids. These characteristics can affect the accuracy
and precision of sub-sampling in the analytical method.
3. Anthracite coal was also selected for packaging primarily to demonstrate
error associated with sub-sampling in the analytical method for certain
types of suspended solids.
k. Fuller's earth, rayon fibers, and anthracite coal were selected for
packaging to obtain the 10,000 vials of quality control samples.
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SECTION III
RECOMMENDATIONS
1. Preparation of the suspended solids samples and execution of the
analytical method should be in accordance with the instructions
specified in Section VI of this report, to minimize variability in
the suspended solids quality assurance data obtained.
2. The sub-sampling step of the suspended solids analytical test method
should be evaluated, to minimize error in the results. Results from
this study indicated that the accuracy of the sub-sampling step is
dependent to some degree upon the dispersion characteristics of the
suspended solids in the sample.
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SECTION IV
DEVELOPMENT AND FEASIBILITY STUDY - PHASE I
LITERATURE SURVEY
Scope and Methodology
The first step in the developmental and feasibility portion of the study
consisted of a literature survey to develop a list of synthetic and natural
compounds with the desired specific gravity and solubility specifications.
Particle size of the compounds was not considered as an initial selection
criterion. (For most of the compounds, the particle size could be changed
to meet the particle size specifications.) Additional information was also
solicited by personal communications (both verbal and written) from manu-
facturers and chemical processors as to the availability of various types of
compounds and their recommendations for additional compounds meeting the
initial developmental criteria.
The second step was a literature survey to gather information which
would characterize natural, municipal, and industrial wastewaters with
respect to specific gravities and particle sizes of the solids in these types
of wastewaters. The information characterizing sanitary wastewaters, storm-
water, and combined sewer overflow was presented in Section I of this report.
However, no information pertaining to the characterization of suspended
solids in the various types of industrial wastewaters was found.
The third step was a literature survey to define acceptable develop-
mental test methods for the proposed compounds with respect to the previously
mentioned design criteria. There were no acceptable test methods found in
the literature for testing the proposed compounds. Therefore, developmental
testing procedures were developed for the feasibility investigation of the
selected compounds.
Specific tests for each of the following investigation requirements were
developed and will be presented in later sections of this report:
Solubi1ity Testing
Wettability and Dispersion Testing
Abrasion Testing
Flocculation Testing
Sub-sampling Recovery Tests
Biodegradabi1ity Testing
Stabi1ity Testing
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Particle size measurements were conducted according to the ASTM Test
Method No. E-20 Analysis by Microscopical Methods for Particle Substances of
Subsieve Sizes. The analytical procedure employed for suspended solids
testing was the method stated in the current EPA manual "Methods for Chemical
Analysis of Water and Wastes."7
Compounds Meeting Initial Design Criteria
A list of compounds which have specific gravities within the range
specified (0.8 - 2.65) and which possibly meet all the other requirements
for synthetic suspended sol ids quality control samples was developed, and
is presented in Table 1.'»2»3>^»5,B
From this initial list, the compounds listed in Table 2 were selected
for the developmental studies, based on established design criteria, avail-
ability of compounds, and manufacturers' recommendations.
The compounds listed in Table 2 were categorized into four groups, by
specific gravity:
Specific Gravities
0.80 - 1.00
1.01 - 1.50
1.51 - 1.99
2.00 - 2.65
Two compounds (wood fibers and gilsonite) were eliminated before the
initial developmental testing. Research and Development personnel in the
wood pulp industry recommended elimination of wood fibers for the following
reasons:
1. Variability of fiber size. Even after fractionating and passing a
pulp slurry through various mesh screens, the thickness of fibers
is extremely variable.
2. Even if it were possible to pulp a single tree, the fibers would
not be uniform, because of great difference in wood growth during
the spring and growth during the summer.
Gilsonite is a very soft hydrocarbon compound that is subject to con-
siderable abrasion and subsequent change in particle size. Gilsonite is
extremely friable; it has very little impact resistance and is easily reduced
to a fine powder.
TECHNICAL APPROACH
Statistical Treatment of Data
When a sample or a finite number of observations from a population are
selected appropriately, one is able to make precise statements concerning
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Table 1
Compounds meeting Specific Gravity and Solubility Requirements
Name Specific Gravity
Aluminum diethyl malonate 1.084
Aluminum Oxide 2.42 - 2.53
(gibbsite, hydra-argi11ite,
bayerite)
Aluminum orthophosphate 2.566
Bismuth tartrate 2.595
Boron (tetra) carbide 2.5
Calcium boride 2.3 - 2.45
Cobalt orthophosphate 2.58?
Carbon 1.8 - 2.25
Iron orthophosphate (vivianite) 2.58
Lanthanum hexaboride 2.61
Magnesium ortho-arsenate 1.788
Silicon 2.00-2.42
Silicon dioxide (cristobalite, 2.1 - 2.66
lechatelierite, quartz, tridymite,
amorphous-opal)
Sulfur 1.92 - 2.07
2, 4, 6, tribromoaniline 2.35
Anthracene 1.25
Hexachlorobenzene 2.044
4, 41 -dibromo-biphenyl 1.897
4, 4' -dichloro-biphenyl 1.439
Cellulose 1.27 - 1.6
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Table 1
(Continued)
Name
Methyl Cellulose
2-Naphthylamine
Triphenyl carbinol
2, 2' -dithiobisbenzothiozole
2-Benzothiozolethiol
p-Benzotoluide
Zinc salt of carbamic acid
Ethyl ether cellulose
Crystopine
Benzene-c i s-hexach1 or i de
Indigotin (Indigo Blue)
di-l-naphthy 1-mercury
Tetraphenyl
Triphenylamine
Dinaphthylmercury (a)
Tetraphenyl urea
Wood Fibers
Natural Clays
Kaolinite
Bentonite
Specific Gravity
1.02
1.061
1.188
1.50
1.00
1.202
1.24
1.315
1.89
1.35
2.318
1.49
0.774
1.929
1.222
0.4 - 1.0
2.60 - 2.63
2.13 - 2.18
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Table 1
(Continued)
Name
Plastics
Nylon
Acetyt
Polyethylene
Teflon
Lucite
Dowex An ion Exchange
Resin 2lK
Gilsonite (natural hydrocarbon)
Polystyrene
'Petrothene
Polythene particles
Alathon
Bakelite
Arizona Road Dust
Amberlite Anion Exchange
Resin IRA-93
(Based on polystyrene)
Non-ionic Resin
XAD-2
Infusorial Earth
Pumice
Bituminous Coal
Anthracite Coal
Fuller's Earth
Rayon Fibers
Styrene Divinyl Benzene
Copolymer Latexes
Specific Gravity
0.9 - 1.45
1.06
1.06
1.05
1.01
0.92
0.96
1.42
2.65
1.03
2.33
1.35
1.12 - 1.35
1.6
2.2 - 2.4
1.52
1.14
10
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Table 2
Compounds Selected for the Initial Developmental Investigations
Group I - Specific Gravity 0.80 - 1.00
Name Specific Gravity
Triphenylamine 0.774
Polythene 0.92
Alathon 0.96
Group II - Specific Gravity 1.01 - 1.50
Petrothene 1.01
Methyl Cellulose 1.02
Non-ionic Resin XAD-2 1.03
Amberlite Exchange Resin IRC-50 1.04
Amberlite Anion Exchange Resin IRA-93 1.04
Polystyrene 1.05
Styrene Divinyl Benzene Copolymer Latexes 1.05
Gilsonite 1.06
Bituminous Coal 1.12 - 1.35
Nylon Fibers 1.14
Anthracene 1.25
Pumice 1.35
Tetraphenyl 1.49
Group III - Specific Gravity 1.51 - 1.99
Rayon Fibers 1.52
Anthracite Coal 1.6
Magnesium arsenate 1.788
4, 41 - dibromo-biphenyl 1.897
Group IV - Specific Gravity 2.00 - 2.65
Hexachlorobenzene 2.044
Silicon dioxide (Sand, Glass Beads) 2.1 - 2.66
Fuller's Earth 2.2 - 2.4
Infusorial Earth 2.33
Aluminum Oxide 2.42 - 2.53
Arizona Road Dust 2.65
11
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the population. Statements concerning the mean, variance, and confidence
limits of the population can be made from the sample by including a
sufficient number of observations. The minimum acceptable for such calcu-
lations is 30 individual observations.°»
Variance and/or standard deviation can be calculated to represent the
measures of variability in the samples from the populations investigated.
The sample variance is generally denoted by S^, and its defining formula is:
n- 1
i= 1
where Xj = Xj , Y-2, • • ., Xn
n
X = Arithmetic Mean =
n
n = The number of sets of values reported in each study.
The standard deviation, S, is defined to be the positive square root of
the variance, S . Its defining formula is:
'V(X-X)2
/_-*
i = 1
To calculate the confidence interval for the mean of a normal distribu-
tion with unknown variance, the sample variance S must be used as an estima-
tion of the population variance.
The quantity t = (X - fi ) / (S/^rf), which is not the standard normal
distribution, but is known as "Student's t" or !'t" distribution, is used.
Since the "t" distribution is symmetric about zero, a 1- a level confidence
interval for /x (the population mean) can be constructed as shown:
= 1 — oc
or
where P = Probability
12
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Analytical Method for Suspended Solids
The analytical method used in this study for the determination of
suspended solids was the method described in the current EPA manual, Methods
for Chemical Analysis of Water and Wastes, 197^, specifying a drying temper-
ature of 103-105°C and requiring a vacuum during filtration to remove excess
water.7 Reeve Angel Type 93^-A, 2.4-cm glass fiber filters and 40-ml Coors
Number 27007 Gooch crucibles were used for the solids analyses. Sample sizes
were 100 ml and 200 ml, depending on the concentration of suspended solids
in the samples.
SolubN ity Testing
The first test procedure applied to the compounds being evaluated in-
volved percent recovery of the compounds after dilution in distilled water
and completion of the analytical procedure. Results included solubility,
retention of the compounds on the standard glass fiber filters, and change
of weight during the analytical procedure. The testing procedure involved
the following steps:
1. Specific amounts of each of the test compounds were weighed on a
Mettler analytical balance, which was certified on a periodic
basis during the project.
2. The specific weights of compounds were diluted to volume in a
250-ml volumetric flask with distilled water.
3. The volumetric flask was shaken vigorously by hand for at least
30 seconds.
k. The total volume of sample (250 ml) was then filtered through a
previously dried and tared Gooch crucible with a fiber-glass
filter pad in place. The flask was thoroughly rinsed with distilled
water to make certain that all of the test compound was removed
from the flask.
5. The Gooch crucible containing the sample was dried at 103°C to 105°C
for one hour, and then desiccated and re-weighed to determine the
percent recovery of the test compound.
Results from the initial solubility testing (six repetitions) are pre-
sented as percent recovery in Tables 3 and 4. A 97 percent recovery value
was selected for determining acceptance or rejection for the solubility
criterion. Percent recovery characteristics of the compounds which passed
the initial solubility tests are shown in Tables 5 and 6; Table 5 presents
the results from 30 repetitions at 250 mg/1 suspended solids, and Table 6
the results from six repetitions at 25 mg/1 suspended solids.
13
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Table 3
Compounds Failing Initial Developmental Tests
Compound
Triphenylarnine
Petrothene
Methyl Cellulose
Amber lite Exchange
Resin IRA-93
Amber lite Exchange
Resin IRC-50
Nylon Fibers
Anthracene
Tetraphenyl
Magnesium Arsenate
4, 4' - dibromo-
biphenyl
Hexachlorobenzene
Aluminum oxide
*Minimum of one or
Specific
Gravity
0.774
1.01
1.02
1.04
1.04
1.14
1.25
1.49
1.788
1.897
2.044
2.42-2.53
two percent recovery
Wettabi li ty
1
1
1
5
5
1
1
2
5
2
2
5
observations.
%
Dl spersion Recovery
1 58.7*
1
1
5 92.7
5 79.2
1 103.1
1 67.3*
2 91.6*
5 90.3
2 82.2*
2 88.3*
1 93.5
Comments
Floats & clings to sides
of container.
Particles agglomerate
in groups and do not
wet or disperse well.
Methyl cellulose
dissolves in water.
Unacceptable recovery.
Unacceptable recovery.
Nylon fibers swel 1
significantly when wetted.
Some fibers agglomerate
and cannot be separated
by vigorous shaking.
These agglomerations pour
out with the sub-sample
and yield percent re-
coveries greater than 100.
Floats and clings to
sides of container.
Floats and settles in
clumps .
Unacceptable recovery,
clogs f i Iter pad.
Particles agglomerate
into large clumps.
Some floats and clings
to sides of container.
Unacceptable recovery.
Difficult to disperse
because of high specific
gravity.
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Table k
Compounds Passing Initial Developmental Tests
Compound
Rayon
Non- ionic Resin
XAD-2
Bituminous Coal
Anthracite Coal
Infusorial Earth
Sand
Glass Beads
Polythene
Alathon
Polystyrene
Pumice
Ful ler 's Earth
Arizona Road
Dust
Specific
Gravity
1.52
1.04
1.12-1.35
1.6
2.33
2.1-2.66
2.1-2.66
0.92
0.96
1.05
1.35
2. 2-2.it
2.65
Wettabi lity
5
3
5
k
5
5
5
4
3
k
5
5
5
Di spersion
5
k
3
3
5
3
3
3
3
4
5
5
k
%
Recovery
97.1
98.1
98.7
99.9
100.5
99.9
99.6
99.4
~~
100.1
99.3
100.5
Comments
Looks excel lent.
Floats, but will disperse
with vigorous shaking,
some cl ingage.
Dispersion characteristics
depend on particle size.
Dispersion characteristics
depend on particle size.
Looks excel lent.
Dispersion characteristics
depend on particle size.
Dispersion characteristics
depend on particle size.
Floats, but will disperse
with vigorous shaking,
some cl ingage.
Floats in groups but wi 11
disperse with vigorous
shaking.
Particles settle and
disperse with vigorous
shaking.
Particles settle and
disperse with vigorous
shaking.
Looks excel lent.
Looks excel lent.
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Table 5
Percent Recovery Tests for Compounds Passing the
Initial Screening Tests
(250 mg/1) at 30 Repetitions
Compound
Polythene
XAD-2
Polystyrene
Bituminous Coal
Pumice
Rayon
Anthracite Coal
Infusorial Earth
Sand
Glass Beads
Arizona Road Dust
Fuller's Earth*
*6 repetitions at 250 mg/1
Specific Gravity
0.92
1.03
1.05
1.12 - 1.35
1.35
1.52
1.6
2.33
2.1 - 2.66
2.1 - 2.66
2.65
2.2 - 2.k
% Recovered
99.4
98.3
100.1
98.3
99.5
98.6
99.9
99.7
100.1
99.4
100.5
99.3
16
-------
Table 6
Percent Recovery Tests for Compounds Passing
the Initial Screening Tests
(25 mg/1) at 6 Repetitions
Compound
Polythene
XAD-2
Polystyrene
Bituminous Coal
Pumice
Rayon
Anthracite Coal
Infusorial Earth
Sand
Glass Beads
Arizona Road Dust
Specific Gravity
0.92
1.03
1.05
1.12 - 1.35
1.35
1.52
1.6
2.33
2.1 - 2.66
2.1 - 2.66
2.65
% Recovered
102.9
98.8
99.4
99.1
100.6
95.7
99.0
99.8
102.0
98.7
100.8
17
-------
Wettability and Dispersion Testing
The second test procedure applied to each compound involved wettability
and dispersion tests to determine if the compounds were hygroscopic, showed
any tendency to cling to the sides of the sample containers, or floated or
settled to the extent that good dispersion could not be obtained with vigorous
shaking in distilled water. Visual observations using empirical scales of
measurement were employed to check the degree of clinging of the compounds
to the sides of the containers, the degree of wettability, and the degree of
dispersion of the compounds in water. The scales of one through five in the
following tabulation were used to determine the degree to which the com-
pounds were wetted and dispersed in water:
1 - Poor Wettabi1ity
2 - Fair Wettabi1ity
3 - Acceptable Wettability
k - Good Wettability
5 - Excellent Wettability
1 - Poor Dispersion
2 - Fair Dispersion
3 - Acceptable Dispersion
k - Good Dispersion
5 - Excellent Dispersion
Results of the wettability and dispersion observations are presented in
Tables 3 and k. A scale measurement of 3 (acceptable wettability and
dispersion) or better was selected for acceptance. Scale measurements of
1 and 2 indicated rejection of the test compounds.
Flocculation Testing
Compounds meeting the previously-defined design criteria were subjected
to mixing tests with other compounds to evaluate the flocculation character-
istics of various combinations of the compounds under investigation. Visual
observations using the following empirical scales of measurement were used
to check the flocculation characteristics of the various mixtures:
1. POOR. Particles agglomerate readily and remain in groups.
2. FAIR. Particles agglomerate readily and tend to remain in groups.
3. ACCEPTABLE. Particles agglomerate to a small degree but break
apart with shaking.
4. GOOD. Particles agglomerate to a very small degree but break
apart very easily.
5. EXCELLENT. No agglomeration of particles.
All compounds passed the flocculation testing when mixed with other com-
pounds, with the exception of XAD-2 and polythene, which flocculated when
mixed (rating 2).
Rayon fibers tended to entrap other particles, especially XAD-2, coal,
and pumice. Rayon entrapped air bubbles and floated when vigorously mixed,
but would settle with gentle agitation.
18
-------
Abrasion Testing
No acceptable method for measuring the abrasion and impact resistance of
the compounds to breaking up into smaller particles was found in the litera-
ture. However, a test procedure involving a Burrell Wrist-Action Shaker
(made by Burrell Corporation of Pittsburgh, PA) seemed appropriate for
abrasion and impact resistance testing. The procedure for simulation of a
"worst case" was as follows:
1. Initial particle size was determined by the previously-mentioned
ASTM method.
2. For each compound, three 10-gram samples and six 500-mg samples
were weighed out on the balance.
3. The weighted compounds were transferred to nine 250-ml volumetric
flasks.
k. The nine volumetric flasks were placed on the Burrell Wrist-Action
Shaker for a 24-hour period at a scale setting of k (on a scale of
0-10, with 10 being the most vigorous shaking obtainable).
5. The six flasks containing 500-mg samples were diluted to volume
with distilled water and filtered to determine the percent
recovery of the compounds under investigation.
6. Particle size was again determined for the compounds in the three
flasks with the 10-gram samples, for comparison with the initial
particle size.
The test compounds were vigorously shaken in the dry state to simulate
conditions of storage and shipping, because it was anticipated that the
compounds would be packaged in the dry state and that the impact and abrasion
forces would be greater in that condition. The results of the abrasion
testing are presented in Table 7. No compounds subjected to abrasion testing
were rejected on the basis of abrasion and impact resistance.
Evaluation of Sub-Sampling
Mixing Technique—
Mixing techniques for sub-sampling stated in the contract to be investi-
gated included the following:
1. Shaking the samples vigorously by hand.
2. Magnetic stirring of samples.
3. Blade agitation stirring of samples.
k. Blending of samples.
However, the last two mixing techniques were eliminated because they would
introduce physical constraints in the subsequent requirement to dilute the
sample to volume in a volumetric flask.
-------
Table 7
Abrasion Testing Results
Compound
Arizona Road
Dust
Glass Beads
Sand
Anthraci te
Coal
Biluminous
Coal
Pumi ce
Rayon
Percent Recovery After
Abrasion Testing
99.8
99.9
99.9
98.4
99.0
99.5
98.9
Uniformity Coefficient (Cu)
Before After
1.50
1.53
1.72
2.95
4.04
1.88
1
.45
.45
.45
.44
.53
.62
.76
.72
.75
2.83
3.66
3.46
3.53
4.00
4.16
2.02
2.11
2.06
Particle Size Before
Mean = 1.63 mm
St. Dev. - 0.573
Var. = 0.328
Rayon Particle Size After Shaking
#1 Sample
Mean = 1.19
St. Dev. = 0.430
Var. = 0.185
#2 Sample
Mean = 1.214
St. Dev. = 0.458
Var. = 0.210
Rayon fibers form small tight balls when shaken in the abrasion test. These balls
are extremely difficult to re-suspend by shaking. A blender was used to re-
suspend the rayon fibers.
Rayon Particle Size After Shaking and Blending Approx. 60 sec.
Mean = 0.963
St. Dev. = 0.468
Var. = 0.219
Random samples were taken for particle sizing with a micro-
scope. 100 particles were counted.
20
-------
The evaluation of mixing techniques and subsequent recovery involved
withdrawing 100 ml sub-samples from one-liter volumetric flasks. The com-
pounds in the flasks were mixed vigorously by hand and by magnetic stirrer
for comparison. The sub-sample volumes of 100 ml were poured into a
graduated cylinder or withdrawn with a volumetric pipet. The results of
the mixing tests are presented in Table 8.
Recovery Tests (Analytical Method)—
Precision and accuracy data for the analytical method were determined
by withdrawing appropriate sample volumes (100 ml or 200 ml) from the
full-volume diluted solids samples into one-liter volumetric flasks in
conformance with the EPA method for determining suspended sol ids.1 The
volumetric flasks were shaken vigorously by hand, and the subsequent sub-
samples were poured into graduated cylinders as contrasted to mixing with
magnetic stirring bars and withdrawing the sample with a pipet. The average
percent recovery was higher, and the range of percent recovery and therefore
the standard deviation were less for shake-and-pour with graduated cylinders
than for magnetic stirring and pipeting.
Extensive tests were performed on the compounds that appeared to be
acceptable for packaging (pumice, rayon fibers, and Fuller's earth). The
results of the mixing tests and sub-sample recovery for these compounds
and for anthracite coal are presented in Table 9. The percent recovery of
sub-sampling appeared to be a function, to some extent, of particle size
because the dispersion characteristics were somewhat dependent on particle
size as exhibited in Tables 8 and 9.
An experiment was conducted to determine the effects of particle size
on the percent recoveries obtainable on Fuller's earth. Fuller's earth was
screened at specific particle sizes, weighed, and diluted with distilled
water to one liter in volumetric flasks, and the sub-samples were removed
by pouring into graduated cylinders for percent recovery analyses. The re-
sults of these particle-size investigations are presented graphically in
Figure 1.
Selection of Compounds for Packaging
The results of the feasibility testing and the observations of the
specific compounds indicated two possible alternative methods available for
sample handling without modifying the 197^ EPA solids analysis procedure.
One alternative was to package compounds over the full range of specific
gravities (0.8-2.65) and particle sizes (0.01-4.5 mm) and to filter the total
sample for the solids analysis. Compounds suitable for this procedure in-
cluded the following:
1. Pum i ce
2. Rayon Fibers
3. Infusorial Earth
k. Fuller's Earth
5. Sand
6. Glass Beads
7. Arizona Road Dust
21
-------
Table 8
Evaluation of Mixing Techniques Using One-Liter Volumetric Flasks
(Vigorous Shaking and Mixing with Magnetic Stirring Bars) 250 mg/1
Compound
XAD-2
Polystyrene
Bi turn! nous
Coal
Pum i ce
Rayon
Fibers
Anthracite
Coal
Mixing
Shake & Pour
(Graduated Cylinder)
Magnetic Stirring
(Graduated Cylinder)
Shake & Pour
(Graduated Cylinder)
Shake & Pour
(Graduated Cylinder)
Magnetic Stirring
(Graduated Cylinder)
Shake & Pour
(Graduated Cylinder)
Magnetic Stirring
(Graduated Cyl inder)
Pi pet
Shake & Pour
(Graduated Cylinder)
Magnetic Stirring
(Graduated Cylinder)
Shake & Pour
(Graduated Cylinder)
Magnetic Stirring
(Graduated Cylinder)
Repetitions
6
6
6
6
6
6
3
3
6
6
6
6
Specific Average %
Gravity Particle Size Recovery
1.03 100-200 microns 102.1
91.0
1.05 1.7 mm Zk.3
1.12-1.35 <150 microns 83. k
96.2
1.35 <75 microns 90.8
92.2
82.3
1.5-2 1.6 mm 93.6
92.3
1 .6 <150 microns 60.8
163.1
Range /
79.7
28.5
0
77.6
85.5
88.6
89.7
76.8
91.**
89.9
1*8.8
68.3
'0 Recovery
- H*5.7
- 106.7
- 80.8
- 90.5
- 107.5
- 92.0
- 95.7
- 91.9
- 95.0
- 93.5
- 78.5
- 290.5
to
-------
Table 8
(continued)
Compound
Fuller's
Earth
Fuller's
Earth
Infusorial
Earth
Glass Beads
Arizona Road
Dust
Arizona Road
Dust
All sub-samples
Mixing
Shake & Pour
(Graduated Cylinder)
Magnetic Stirring
(Graduated Cylinder)
Shake & Pour
(Graduated Cylinder)
Magnetic Stirring
(Graduated Cylinder
Pi pet
Shake & Pour
(Graduated Cylinder)
Magnetic Stirring
(Graduated Cylinder)
Pi pet
Shake & Pour
(Graduated Cylinder)
Magnetic Stirring
Shake & Pour
(Graduated Cylinder)
Shake & Pour
(Graduated Cylinder)
were 100 ml samples.
Repetitions
6
6
3
3
3
6
6
6
6
6
6
6
Specific Average %
Gravity Particle Size Recovery
2.2 - 2.4 <150 microns 81.9
87.3
2.2 - Z.k <45 microns 92.9
9L8
94.3
2.33 8 microns 93.1
102.3
91.7
2.61 - 2.65 0.9 - 1.23 mm 0
1.0
2.65 100-200 microns 7.1
2.65 20-40 microns 77.9
Range °/
78.2
83.9
92.6
89.4
92.7
88.5
99.7
89.1
0
5.2
73.9
3 Recovery
- 84.4
- 90.6
- 93.3
- 94.7
- 97.3
- 97.4
- 103.7
- 95.2
0
- 2.0
- 9.9
- 79.6
-------
Table 9
Mixing Test Results (Shake & Pour) with Graduated Cylinder
Concentration
ma/L
Sub-Sample Actual Particle
Compound Size (ml) Proposed Av«r«g« Size
Pumice* 100 100 104.8 < 45 microns
Pumice*
Pumice*
Rayon**
Rayon**
Rayon**
Rayon**
Rayon**
Rayon*
Fuller's Earth**
Fuller's Earth**
Fuller's Earth**
Fuller's Earth**
Fuller's Earth**
Fuller's Earth*
Nylon Fibers***
Anthracite Coal**
Anthracite Coal**
Anthracite Coal**
Anthracite Coal****
* 3 repetitions
** 30 repetitions
*** 12 repetitions
**** 6 repetitions
100
100
200
200
100
ICO
100
100
200
200
100
100
100
100
100
200
100
100
100
250
1000
27
50
100
250
855
1000
27
50
100
250
855
1000
250
27
250
855
250
257.3
1007.8
27.4
52.1
102.0
251.9
854.9
1011.8
27.5
52.6
111.7
254.2
855.5
1007.9
250.8
28.5
253.4
861.5
251.3
< 45 microns
< 45 microns
0.5 «m
0.5 rm,
0.5 irni
0.5 irni
0.5 mm
0.5 out
< 45 microns
< 45 microns
< 45 microns
< 45 microns
< 45 microns
< 45 microns
0.5 mm
£ ISO microns
< 150 microns
< 150 microns
44 - 150 microns
Average %
Recovery
90.7
92.4
90.3
98.3
97.3
97.4
97.5
99.1
98.8
99.6
94.5
96.4
96.7
96.0
95.3
103.1
92.3
77.4
74.4
69.1
Range %
Recovery
88.8 - 92.6
91.3 - 93.1
89.3 - 90.3
85.3 -107.5
90.0 -102.5
93.9 -101.4
95.1 -100.0
97.1 -101.5
97.8 - 99.7
93.8 -105.6
88.4 -101.4
92.3 - 99.1
93.4 - 99.2
93.0 - 98.5
94.8 - 95.6
98.7 -109.0
76.6 - 106.0
66.9 - 85.1
65.7 - 81.9
63.9 - 72.5
Standard
Deviation
(Percent)
1.90
0.96
1.05
4.69
3.47
2.12
1.23
1.31
0.95
3.80
2.91
1.88
1.63
1.67
0.46
2.57
7.88
4.21
4.26
3.65
Variance
3.61
0.93
1.10
22.01
12.05
4.51
1.52
1.71
0.91
14.48
8.47
3.55
2.65
2.80
0.21
6.61
62.03
17.74
18.11
13.29
•Standard
Deviation
(IM)
0.23
0.26
1.06
0.18
0.32
0.18
0.29
0.67
1.00
0.10
0.28
0.22
0.46
1.39
O.SI
0.56
0.42
2.94
3.77
1.07
Variance
0.05
0.07
l.ll
0.03
0.10
0.03
0.08
0.46
1.00
0.01
0.08
0.05
0.2)
1.93
0.26
0.32
0.18
8.66
14.25
1.13
Standard
Deviation
(M/L)
1.99
2.47
10.58
1.29
1.81
2.16
3.10
11.20
9.61
1.05
1.53
2.10
4.14
14.29
4.67
6.45
2.25
10.67
36.70
9.17
. Variance
3.96
6.10
111.96
1.65
3.27
4.68
9.60
125.42
92.39
1.09
2.34
4.41
17.17
204.10
21.50
41.55
5.04
113.81
1346.88
84.13
-------
PERCENT RECOVERY
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However, this procedure would yield information only on the analytical
technique, with no regard to sub-sampling technique and procedure. The
second and best alternative would be to package one or a few compounds in
the very small particle-size fractions that would allow accurate sub-sampling.
The compounds indicated as acceptable for the second alternative were:
1 . Pum i ce
2. Rayon Fibers
3. Fuller's Earth
The second alternative was chosen for selecting the compounds to be
packaged as quality control and performance evaluation samples. Since pumice
and rayon fibers were close in specific gravity and since the particle size
of each can be varied, the rayon fibers were chosen because of higher percent
recoveries during sub-sampling. Consequently, the following compounds shown
as compounds passing the initial developmental tests in Table k were rejected
for packaging:
Compound Comments
1. Non-ionic Resin, XAD-2 Erratic sub-sampling recovery.
2. Bituminous Coal Low sub-sampling recovery.
3. Infusorial Earth Low sub-sampling recovery. Same
specific gravity as Fuller's Earth.
4. Sand Low sub-sampling recovery.
5. Glass Beads Low sub-sampling recovery.
6. Polythene Floats, yielding erratic sub-sampling.
7. Alathon Floats, yielding erratic sub-sampling.
8. Polystyrene Low sub-sampling recovery.
9. Pumice Approximately same specific gravity
as rayon fibers.
10. Arizona Road Dust Low sub-sampling recovery.
Styrene di vinyl benzene (specific gravity - 1.05) was also rejected for
packaging because of initial cost (approximately $45 per 15 ml) and handling
problems. It is packaged in liquid form and cannot be dried without changing
properties.
The compounds selected for packaging included the following:
Fuller's Earth - particle size <^5 microns
Rayon Fibers - 1.5 denier*, 0.5 mm long
Anthracite Coal- particle size <150 microns
*A measure of the fineness of rayon yarn. 1.5 denier yarn weighs 1.5 grams
per 9,000 meters.
26
-------
Fuller's earth and rayon fibers met all the design criteria established
for the synthetic suspended solids quality control and performance evalua-
tion samples. The reason for packaging anthracite coal as a suspended solids
quality control sample was to show some of the problems involved in the
suspended solids determination procedure.
Biodegradabi1ity Testing
The biodegradabi1ity tests were conducted by measuring biochemical
oxygen demand (BOD) in BOD bottles according to the procedure described in
the 13th Edition of Standard Methods for the Examination of Water and
Wastewater. ' The distilled water, phosphate buffer solution, magnesium
sulfate solution, calcium chloride solution, ferric chloride solution, sodium
sulfite solution, and dilution water were prepared according to the instruc-
tions. Therefore, adequate nutrients were supplied by the prepared solutions
added to the dilution water.
Each bottle was seeded with microorganisms from a standard house seed
taken from the West Chester, PA municipal sewage treatment plant. The BOD
bottles were incubated at 20°C for a five-day period. The dissolved oxygen
(DO) was determined with a membrane electrode DO meter, which was checked
and standardized before use.
Each of the three compounds selected for packaging was tested at three
concentrations for the five-day BOD analyses. Standards of glucose/glutamic
acid were also incubated for the five-day period. Five mi 11 Miters of the
standard were placed in each bottle yielding five-day BOD's of 180 to 20k
mg/1. Each condition of compounds and standard was repeated six times.
Fuller's earth and anthracite coal showed no biodegradation in the
6005 test procedures, but the rayon fibers showed slight biodegradation at
the two highest concentrations. The results of the biodegradabi1ity investi-
gations are presented in Table 10.
Stability Testing
Fuller's earth and anthracite coal were packaged mechanically at three
weights for the stability testing; the rayon fibers were hand weighed and
packaged at the same three weights.
The weights of the packaged compounds were then checked at 30, 60, and
90 days for comparison with the packaged weights at zero time to evaluate any
possible problems associated with biodegradabi1ity, volatility, or any
change of any other characteristics during storage of the packaged compounds.
Comparison of the 30-, 60-, and 90-day data to time zero weights dis-
closed no significant evidence of increasing weight loss with time. Weight
loss of rayon fibers during both the 60-day and 90-day investigation periods
was less than the weight loss during the 30-day period. Weight loss of
Fuller's earth during the 90-day period was less than the weight loss during
27
-------
Table 10
Results of Biodegradabi1ity Tests
(Five-Day BOD Tests) for Rayon, Fuller's Earth, and Anthracite Coal
Sample Description Date
Glucose/Glutamfc Acid Standard (5 mJ/bottle) 11/6/75
Rayon-Low Concentration
Rayon-'Medium Concentration
Rayon^Hlgh Concentration
Fuller's Earth-Low Concentration
Fuller's Earth-Medium Concentration
Fuller's Earth-High Concentration
Glucose/Glutamic Acid Standard (5 ml/bottle) 11/7/75
Anthracite-Low Concentration
Anthracite-Medium Concentration
Anthracite-High Concentration
All Tests conducted at 6 Repetitions.
Avg. D.O. Range D.C.
Depletion Depletion Avg. BOD Range BOD,.
(mq/L) (mq/L) (mq/L) 5 (mq/L) '
3.2 3.0 - 3.3 189 180 - 198
< 0.1
0.8 0.7 - 1.0 2.4 2.1 - 3.0
3.1 2.9 - 3.5 9.3 8.7 - 10.5
< 0.1
< 0.1
< 0.1
3.3 3.2 - 3.4 196 192 - 204
< 0.1
< 0.1
0.2 0.2 0.6 0.6
to
00
-------
the 60-day period. Weight loss of anthracite coal was random over the 30-,
60-, and 90-day investigation periods and exhibited no trends or patterns in
any of the data.
Statistical analyses were performed to test the significance of the
difference of the weights observed at SO days compared to weights at zero
time by the t test.'^ The difference in the weights observed did not prove
to be significant atOC = 0.01, with one exception, Fuller's earth at the
lowest weight packaged.
Percent Recovery Tests on Mixtures of Fuller's
Earth, Anthracite Coal, and Rayon Fibers
Rayon fibers and Fuller's Earth, rayon fibers and anthracite coal, and
Fuller's earth and anthracite coal were each mixed at a 50:50 weight ratio
at a total concentration of 250 mg/1 per sample. In addition, rayon fibers,
Fuller's earth, and anthracite coal were mixed at a 33.3:33.3:33.3 weight
ratio at a total concentration of 250 mg/1 per sample. Each of these mix-
tures was added to a one-liter volumetric flask and brought to volume with
distilled water. The samples were then shaken vigorously by hand, and a
sub-sample of 100 ml was poured into a graduated cylinder for suspended
solids analysis to determine the percent recovery. The results of these
mixing and percent recovery investigations are presented in Table 11.
The percent recovery obtainable by the analytical method for the mixture
of rayon fibers and Fuller's earth was excellent (average 99.5 percent).
However, the percent recoveries for the other mixtures containing anthracite
coal were all less than 90 percent. The percent recoveries obtained were
as would be expected without flocculation reactions. Very good percent
recoveries were obtainable with rayon fibers and Fuller's earth alone,
whereas very poor recoveries were obtainable with anthracite coal alone.
-------
Table 11
Compound Mixing Tests Results
Compound
Rayon Fibers*
Fuller's Earth
Rayon Fibers*
Anthracite Coal
Fuller's Earth*
Anthracite Coal
Rayon Fibers*
Fuller's Earth*
Anthracite Coal
Rayon Fibers at 0.
Fuller's Earth at
Anthracite Coal at
6 repetitions
Total Standard
Ratio Size (ml) (mq/L) Recovery Recovery (Percent) Variance
50:50 100 250 99.5 99.0 - 100. 1 0.50 0.25
50:50 100 250 87.4 85.5 - 91.7 2.28 5.19
50:50 100 250 79.2 77.3 - 82.1 1.67 2.80
33.3:33-3:33.3 100 250 84.1 82.8 - 85.2 0.79 0.62
5 mm particle size
< 45 micron particle size
< 150 micron particle size
Standard Standard
(ma) Variance (ma/L) Variance
0.12 0.015 1.20 1.44
0.55 0.31 5.50 30.25
0.47 0.22 4.70 22.09
0.45 0.20 4,50 20.25
-------
SECTION V
PACKAGING OF COMPOUNDS - PHASE II
PREPARATION OF COMPOUNDS FOR PACKAGING
Fuller's earth, rayon fibers, and anthracite coal were carefully pre-
pared for packaging. These compounds were purchased in a pure state and
washed several times in distilled water to remove any soluble impurities
that might have been present. These compounds were then dried overnight at
103-105°C to remove moisture. The rayon fibers were then ready for pack-
aging, because they were previously sized. The Fuller's earth and anthracite
coal were ground or milled and sized to the correct sizes. These compounds
were then dried again to remove any moisture that might have been picked up
during the sizing operations. These compounds were then ready for packaging.
PACKAGING REQUIREMENTS
Number and Type of Samples
The numbers and types of packages of the compounds (rayon fibers, anthra-
cite coal, and Fuller's earth) chosen for packaging by EPA are presented
be 1ow:
Compound
Rayon Fibers
Fuller's Earth
Anthracite Coal
Weight (mg)
Low
Med ium
High
Sub-Total
Low
Medium
High
Sub-Total
Low
Med ium
High
Sub-Total
No. of Vials
1,111
1,111
1 ,111
3,333
2,711
1,111
1,111
^,933
1,111
311
311
1,733
31
-------
This combination of weights and number of vials at each weight was
chosen for two principal reasons:
1. To obtain variety in the packaged weights.
2. To package fewer vials of anthracite coal, because the main purpose
of this compound is simply to indicate some of the problems of the
test procedure.
Packaging Technique
Weston used a semi-automatic packaging instrument (Perry Model LM-14
Accofil Portable Powder Filling Machine) to package the anthracite coal and
Fuller's earth. However, the instrument could not be used to package the
rayon fibers accurately, because of their fluffy physical nature. Therefore,
the rayon fibers were hand weighed and packaged. The actual packaged weights
of rayon fibers were recorded for each vial.
Strict quality control procedures were employed during preparation of
the compounds and the packaging vials and caps, and during the actual pack-
aging operations. Rigid laboratory standards concerning equipment, vials
and caps, and housekeeping practices were enforced. Vials were thoroughly
washed in dilute hydrochloric acid solution, rinsed, dried at 103-105°C, and
desiccated before being used for packaging. All the packaging operations
were conducted in a temperature- and humidity-controlled balance room. Cali-
bration of the packaging instrument and quality control checks on the
instrument and hand-packaged vials were performed on a routine basis, as
described in the sub-section on quality control.
Instrument Packaging Precision
Anthracite coal and Fuller's earth were employed in packaging operations
with the packaging instrument to determine the precision of packaging at
specified weights. As the Fuller's earth and anthracite coal were final
packaged, approximately five percent of the packaged vials were checked for
packaging precision. Quality control spot checks of each type of package
combination were made, and these quality control checks were included in the
precision measurements of the instrument. Packaging precision was shown to
be within ±3 percent of the average packaged weights.
Quali ty Control
Rigid quality control procedures were utilized throughout the packaging
operations to insure confidence in the precision and accuracy of the pack-
aged compounds weights. The packaging instrument was calibrated on a daily
basis, and approximately five percent of the packaged vials were checked
for packaging precision at the time of packaging. The hand-packaged weights
were also checked by re-drying approximately five percent of the packaged
vials and determining the packaged weights for comparison with the initial
recorded weights.
32
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Additional vials of rayon fibers, anthracite coal, and Fuller's earth
were packaged at each weight combination for quality control spot checks
of the packaged weights by a senior chemist who had not been associated with
the packaging of the vials. The samples for quality control checks were
randomly selected from each packaged combination of compounds and weights.
These quality control checks again established that the packaged weights were
within i3 percent of the average packaged weights.
33
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SECTION VI
DISCUSSION
STATISTICAL EVALUATION OF DATA
Calculations were conducted to determine the precision of the analytical
results that could be expected by an analyst performing the suspended solids
test from the packaged compounds (rayon fibers, Fuller's earth, and anthra-
c i te coa1).
With the concurrence of the EPA statistician, the packaging precision
data for Fuller's earth and anthracite coal, and the analytical method
precision data were combined into a single precision statement. To develop
this precision statement for each compound weight, it was necessary to com-
pare the results of the packaging and the analytical method at the same
weights; however, the packaged weights and those used in the analytical
method evaluation were different. To put the data on the same basis, a plot
of the standard deviations of the analytical method for each compound versus
the corresponding weights was made. These plots (Figure 2) indicated
straight-line relationships. Consequently, the standard deviations for
analytical method at the packaged weights of the compounds were read
directly from these graphs.
The combined standard deviation of the analytical method and packaging
was then calculated as follows:
•K
S12 •+ S22
where S = Combined standard deviation
S-j = Standard deviation of analytical method
$2 = Standard deviation of packaging
The percent recovery of the analytical method was also determined for
the actual packaged weights of compounds by plotting the average percent
recovery versus average concentration. The combined precision of analytical
method and packaging was then determined around the sample mean, which was
taken to be the average packaged weight multiplied by its respective average
percent recovery.
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O
p
O
EC
36
34
32
30
28
26
24
22
20
18
16
14
10
8
6
4
2
Anthracite Coal
Fuller's Earth
Rayon Fibers
I
I
100 200 300 400 500 600 700 800
AVERAGE CONCENTRATION. mg/L
900
1,000
1,100 1,200
Figure 2. Standard deviations of analytical method versus concentration.
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SYNTHETIC SUSPENDED SOLIDS ANALYSIS
Recent investigations by EPA's Environmental Monitoring and Support
Laboratory (EMSL), Cincinnati, OH, and an independent study by the National
Council of the Paper Industry for Air and Stream Improvement, Inc. were
undertaken to examine the effects of procedural differences on measured
presence of non-filterable residue (suspended solids)." Significant
variations in non-filterable solids capture were found to result from the
following: type of filtering medium used; type of filter holder apparatus
used to support the medium; volume of sample filtered (volume to filter
area); and post-washing procedure.
These findings led to the recommendation that a uniform test procedure
be developed and employed for measuring non-filterable residue or suspended
sol ids.
Standard procedures for transferring the pckaged compounds to one-liter
sample containers (volumetric flasks) and for performing the suspended solids
analysis are recommended in the following paragraphs.
Preparation of Quality Assurance Samples
for Suspended Solids Analysis
The following procedure is recommended for preparation of the quality
assurance samples for suspended solids analysis:
1. Tap contents (compounds) to bottom of vial.
2. Remove rubber-lined seal from vial (being careful to avoid losing
any particles that may be clinging to the rubber lining).
3. Clean the rubber lining by flushing thoroughly with distilled water
into a one-liter volumetric flask (Class A glassware); with anthra-
cite coal, rubbing the lining with a glass rod may be required for
complete removal. Clean until no particles remain attached to
1 in ing.
k. Pour contents of the vial into the volumetric flask through a
glass funnel.
5. Continually rinse and transfer remaining contents of the vial into
the volumetric flask until no particles remain in vial.
6. Dilute to one-liter mark.
Analytical Method for duality Assurance Suspended
Solids (Non-Filterable Residue)
The procedure and the apparatus recommended for performing the suspended
solids analysis are as stated in the EPA Manual of Methods for Chemical
36
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Analysis of Water and Wastes.7 The procedure for determining suspended
solids concentrations is as follows:
1. Insert recommended glass fiber filter disc into bottom of suitable
Gooch crucible (4.7 cm or 2.2 cm), with the wrinkled surface of
the disc facing upward.1^
2. Apply vacuum to the assembled filtration Gooch crucible in the
f i 1 ter apparatus.
3. While vacuum is applied, wash the disc with three successive 20-ml
volumes of distilled water. Remove all traces of water by con-
tinuing to apply vacuum after water has passed through.
4. Disconnect the vacuum, remove the Gooch crucible with the filter
paper in place, and dry it in an oven at 103-105°C for one hour.
5. Remove the Gooch crucible from the oven, and place it in a
desiccator until cooled to room temperature. The Gooch crucible
can be stored in the desiccator until needed, but should be
weighted immediately before use.
6. Place the previously dried, desiccated, and tared Gooch crucible
with the glass fiber filter disc into the filtering apparatus,
and begin suction.
7. Shake the sample diluted to 1-liter volume vigorously by hand for
at least 30 seconds.
8. Rapidly transfer the 100-ml or 200-ml subsample by means of a
graduated cylinder to the Gooch crucible.
9. Rinse the graduated cylinder thoroughly with distilled water,
, pouring the water through the Gooch crucible (minimum of three
successive 20-ml volumes of distilled water).
10. Carefully remove the Gooch crucible from the crucible adaptor.
11. Dry in the drying oven at 103-105°C for one hour.
12. Cool in a desiccator for 30 minutes.
13. Weigh the Gooch crucible after the 30-minute desiccation period.
The suspended solids (non-filterable residue) concentration of the
quality assurance sample can then be calculated as follows:
Suspended Solids, mg/1 = (A"B) * 1>000
where A = Weight of Gooch crucible plus solids (residue)
B = Weight of Gooch crucible
C = ml of sample filtered
37
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SECTION VII
REFERENCES
1. Dalrymple, R.J., S.L. Hodd, and O.C. Morin. Physical and Settling
Characteristics of Particulates in Storm and Sanitary Wastewaters.
Environmental Protection Technology Series EPA-670/2-75-011.
April 1975. 33 P.
2. Sullivan, R.H., M.M. Cohn, J.E. Ure, and F.E. Parkinson. The Swirl
Concentrator as a Grit Separator Device. Environmental Protection
Technology Series EPA-670/2-74-026. June 1974. 93 p.
3. Sullivan, R.H., M.M. Cohn, J.E. Ure, F.E. Parkinson, and G. Galiana.
Relationship Between Diameter and Height for the Design of a Swirl
Concentrator as a Combined Sewer Overflow Regulator. Environmental
Protection Technology Series EPA-670/2-74-039. July 1974. 44 p.
4. The Swirl Concentrator as a Combined Sewer Overflow Regulator Facility.
Environmental Protection Technology Series. EPA-R2-72-008.
September 1972. 179 p.
5. Shelley, P.E., and G.A. Kirkpatrick. Sewer Flow Measurement-A State-
of-the-Art Assessment. Environmental Protection Technology Series
EPA-600/2-75-027. November 1975. 424 p.
6. American Society for Testing and Materials Standards (General Test
Methods). Philadelphia, American Society for Testing and Materials,
1969. Part 30, p. 106-118.
7. Manual of Methods for Chemical Analysis of Water and Wastes. U.S.
Environmental Protection Agency Technology Transfer EPA-625/6-74-003.
197**. p. 268-269.
8. Handbook of Chemistry and Physics. Cleveland, The Chemical Rubber
Company, Forty-Seventh Edition. 1966.
9. Snedecor, G.W., and W.G. Cochran. Statistical Methods. 6th ed.
Iowa State University Press. 1967. p. 60.
10. Arkin, H., and R.R. Col ton. Statistical Methods as Applied to Economics,
Business, Psychology, Education, and Biology. 4th Ed. Revised, Barnes
and Nobel, Inc. 1956. p.
38
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11. Standard Methods for the Examination of Water and Wastewater. 13th Ed.
Washington, APHA, AWWA and WPCF, 1971. p. 489-^95.
12. Yamane, T., Statistics - An Introductory Analysis. 3rd Ed., Harper and
Row, Publishers 1973. p. 659-669, 1080.
13. A Preliminary Review of Analytical Methods for the Determination of
Suspended Solids in Paper Industry Effluents for Compliance with
EPA-NPDES Permit Terms. NCASI Special Report No. 75-01. 1975. 20 p.
14. Analytical Quality Control Newsletter. U.S. Environmental Protection
Agency, Environmental Monitoring and Support Laboratory, Cincinnati,
Ohio. January 1976. p. k.
39
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600M-76-052
2.
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
Development of Suspended Solids Quality Control and
Performance Evaluation Samples
5. REPORT DATE
October 1976 (Issuing date)
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Enos L. Stover and Peter J. Marks
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORG'\NIZATION NAME AND ADDRESS
Roy F. Weston, Inc.
Weston Way
West Chester, Pennsylvania 19380
10. PROGRAM ELEMENT NO.
1H0621
11. CONTRACT/GRANT NO.
68-03-2333
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Monitoring and Support Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final 6/30/75 - 5/20/76
14. SPONSORING AGENCY CODE
EPA-ORD
15. SUPPLEMENTARY NOTES
16. ABSTRACT
A two phase study was conducted to develop a synthetic suspended solids sample
for use as quality control check and performance evaluation within environmental
monitoring laboratories. The first phase consisted of a feasibility study to
determine compounds that exhibited the optimum physical and chemical properties
for synthetic suspended solids samples, and the second phase involved production of
suspended solids samples in individual containers.
Compounds investigated that met all the design criteria included rayon fibers and
Fuller's earth. A total of 10,000 quality control samples consisting of rayon
fibers, Fuller's earth and anthracite coal were packaged for completion of the
project. Anthracite coal was packaged to demonstrate the variability in the sub-
sampling step of the suspended solids test method with certain types of solids.
This report was submitted in fulfillment of Contract Number 68-03-2333 by Roy F.
Weston, Inc. under the sponsorship of the Office of Research and Development, U.S.
Environmental Protection Agency. Work was completed in April 1976.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Quality Assurance
Standards
Accuracy
Calibrating
Quality Control
Performance tests
Validity
07D
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
SO
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
;(U.S GOVERNMENT PRINTING OFFICE: 1976-757-056/5'i25 Region No. 5-11
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Office of Research and Development
Technical Information Staff
Cincinnati, Ohio 45268
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