EPA-600/4-76-052 October 1976 Environmental Monitoring Series ------- 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. ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- ------- 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 ------- 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 ------- 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. ------- 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. ------- 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. ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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. ------- 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. ------- 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 s s VJ o c 3 ro o \ & o vn CD i m •o > 3D ; (D •n (0 u>" N m O 3D O o o A o ------- 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 ------- 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 ------- 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. ------- 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. ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Research and Development Technical Information Staff Cincinnati, Ohio 45268 OFFICIAL BUSINESS PENALTY FOR PRIVATE USE, S3OO AN EQUAL OPPORTUNITY EMPLOYER POSTAGE AND FEES PAID U.S. ENVIRONMENTAL PROTECTION AGENCY EPA-335 Special Fourth-Class Rate Book C3 T If your address is incorrect, please change on the above label; tear off; and return to the above address. If you do not desire to continue receiving this technical report series, CHECK HERE (H, tear off label, and return it to the above address. ------- |