A COMPREHENSIVE MUNICIPAL REFUSE

CHARACTERIZATION PROGRAM

HERBERT I. HOLLANDER Saunders & Thomas, Inc.

Pottstown, Pennsylvania

JOHN K. KIEFFER Gilbert Associates, Inc.

Reading, Pennsylvania

ABSTRACT

Controlled release and utilization of the thermal energy potential in mixed municipal refuse requires fundamental identification of its physical consti­tuent make-up and thermo-chemical character.

This discussion reports the approach and results of a vigorous effort to sort into 16 basic consti­tuents five entire truck loads of municipal refuse identified to be representative of the major socio­economic areas of the Community. In addition to the sorting activity to determine the constituent mix, randomly selected samples of the combustible constitutents were collected from each sorted truck load for basic fuels analysis.

Concurrent with the waste characterization pro­gram, a test program of a wet electrostatic precipi­tator module was conducted wherein the gases from combustion of the refuse were characterized ahead of and following this advanced air pollution con­trol device. A companion report of this activity is also to be discussed at this conference.

PERSPECTIVE

Any system employed to process wastes must have the inherent flexibility to cope with the variability of its character. However, endeavoring to characterize wastes, particularly municipal wastes, is akin to focusing on a target moving erratically in three dimensions. There are myriad influences and of fluctuating intensity, continually altering the quantity, composition and physical/

VIRGIL L. ELLER Central Wayne County Sanitation Authority

Dearborn Heights, Michigan

JUNIUS W. STEPHENSON Havens & Emerson, Inc.

Saddlebrook, New Jersey

chemical character of the material. The intensity of the influences can vary from Community to Community, from within the Community, from year to year, from season to season and even frwn day to day. Consequently "defining" the specific nature of transitive municipal waste could become illusory.

However, there must be a basis for economic analysis, design and subsequent operation with prescribed expectations accounting for the vari­ability in the material as it may be encountered. Although particularly significant when embarking on a new program for processing wastes for re­covery of the inherent material and/or fuel re­sources or thermal reduction with/without energy recovery, actual characterization of the wastes can also be very informative for continuing operations of existing facilities where optimization is an ob­jective or monitoring is desired to avoid system malfunction. Rehabilitation or retrofit situations also benefit by realistic attempts at redefinition or

•

recharacterization of the feedstock, particularly when marked changes occur resulting from legisla­tion or the economy in general.

For many years these precepts have been recognized and much effort has been expended in the characterization endeavor at various locations in the U.S., Canada and overseas. These efforts were conducted by a spectrum of diSciplines (sectors), i.e., federal and state agencies, municipal administrations, involved industries, plant opera­tors, consulting engineers, academic researchers, and even citizen groups. Since there were no

221

standard methods, prcedures or programs, each investigator resorted to his own devices, ingenuity, resourcefulness and expediency in satisfying the current need for information and data. Conse­quently, correlations of the data obtained by many investigators having employed an array of techniques and procedures for differing assort­ments of constituents still prompts misgivings regarding the confidence level in the information reported.

The focus of uncertainty is considered to reside in the selection of samples for characterization which can be deemed representative of the large mass of material encountered each day and in part in the analysis technique(s). *

Some investigators endeavored to characterize "their own household discards" with the expecta­tion that they would be typical of the community. Others had sorted and characterized crane bucket loads of material randomly drawn from an inciner­ator pit . . . or endeavored to obtain grab samples from newly dumped loads of material on a tipping floor or landflli. The size of each grab sample, the number of samples and the location taken from the mass of material were areas of uncertainty in establishing the credibility of the data generated with reproducibility of the data being the objec­tive.

Statistical analyses have been made and reported by several researchers regarding the efficacy of drawing upon many samples of small size, 200-300 lb (90-140 kg), for determining waste com­position and subsequent chemical analysis [1-4] . Although there is apparent recognition that these as-discarded, heterogeneous materials are coarse sized, fine sized, dense, compressible, loose, bagged or boxed, do not have granular characteristics, will not flow, will not blend, will segregate, the cone and quartering technique is nevertheless employed frequently to obtain "the representative sample" for analysis. The sample selection technique is highly dependent on crew judgement and can easily become inadvertently biased.

It is in the above context that a refuse sorting and characterization program was undertaken at the long established, conscientiously operated Central Wayne County Sanitation Authority

'These concerns surfaced repeatedly when attemPting to

finalize mutually beneficial commercial agreements. The

formation objectives of ASTM E-38 Committee on Re­

source Recovery was to address these concerns with

consensus guidelines and standards which can be the

basis of agreements minimizing many of the uncertain­

ties.

222

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(CWCSA) incineration facility in Dearborn Heights, Michigan.

IMPETUS AT CWCSA

This thermal reduction plant, Fig. 1, in opera­tion since 1964 is currently equipped with three air cooled refractory, continuous flow furnaces, two nominally rated at 250 tons/day (227 tid) and the third at 300 tons/day (272 t/day).

The pressures of ever rising operating costs, the imposed requirement for still more refined air pol­lution control (albeit no attributable citizen com­plaint since plant start-up) and the intensifying need �r energy conservation had prompted CWCSA to investigate the technical, operational and economic feasibility of an energy recovery retro-fit program for steam-power generation. The preliminary conceptual engineering investigations revealed sufficient promise to warrent DOE sup­port for an in-depth engineering-economic analy­sis and general design.

The merits of the concept for CWCSA are to: 1. Enhance and maximize use of an existing

site for processing wastes - to which the Communi­ty has long been acclimated.

2. Prolong the useful life of the existing facili­ties.

3. Provide all heating and power requirements for plant operation . . . energy independence.

4. Provide for cogeneration of steam for process use, heating/cooling and electric power - the infinite energy receptor.

5 . Provide incentive for nearby urban renewal or industrial development.

6. Provide constraint on ascending operating costs (perhaps ultimately diminishing them) through fuel/power cost avoidance and revenues from surplus steam/power generation.

7. Support up-dating of air pollution control systems.

8. Displace and conserve the fuel equivalent of almost one barrel of oil per ton of refuse con­sumed while generating approximately 500 kW -potentially 96,000,000 kWh per year at CWCSA.

Should the expectations be confirmed and pro­ject implementation and operation be successful, the approach at CWCSA could become a pattern for emulation at other existing incinerator plants.

Further discussions on the concept feasibility for CWCSA and discussions on the investigation and field testes) of advanced wet electrostatic precipitator modules at CWCSA are covered in a

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•

•

•

. .

•

• • •

FIG. 1

companion paper to be presented at this con­ference [5] .

THE CHARACTERIZATION PROGRAMS

Although the CWCSA management and opera­ting personnel have successfully processed almost 2.5 million tons (2.3 million t) of municipal refuse since start-up in 1964, identification of the changing character of the refuse has been only based on observation.

As part of the retrofit feasibility investigation an idealized program plan was conceived whereby simultaneous integrated defmition activities would take place to:

characterize the solid waste to be consumed, - characterize the combustion gases therefrom, - characterize the performance of a wet electro-

static precipitator, and over the longer term char­acterize the condition of a screen of watertubes operating at conditions simulating that of the leading tubes of a heat recovery boiler. Unfortu­nately this integrated characterization program was not achieved .. . perhaps it was too ambitious at the time. However the experience in specifically defining each activity and endeavoring to cope with the coordination complexities has confirmed that an integrated program of this nature is at­tainable and would provide correlated information unobtained heretofore.

The waste characterization program and the performance characterization of the wet electro­static precipitator was achieved albeit not concur­rently - but in consecutive weeks.

223

WASTE CHARACTERIZATION -

SORTING AND SAMPLING

The waste characterization program encom­passed the sorting and sampling of some 66,000 lb (30,000 kg) of municipal refuse on each of five consecutive days during the last week of August 1979. The refuse was sorted into 16 categories with samples taken for laboratory analysis of only those ten refuse constituents usually considered combustible.

REFUSE CONSTITUENTS

Combustibl e

1. Newsprint 2. Other paper 3. Diapers 4. Textiles/Garments 5. Plastics - film 6. Plastics - rigid 7. Food Wastes 8. Wood 9. Yard Wastes (essentially

grass cl ippings) 10. Sweepings (floor of

sorting area)

Noncombustible

11. Ferrous 12. Aluminum 13. Nonferrous 14. Glass 15. Brick 16. OBW (oversize bulky

wastes)

SERVICE DISTRICT AND DEMOGRAPHIC

CONSIDERATIONS

In the CWCSA service districts, refuse is col­lected from each residence only once per week. This fact eliminated the usual concern in account­ing for the daily variations in residential waste character, i.e., mid-week versus week-end. Most of the refuse is collected under contract and delivered

to CWCSA for disposal either by incineration or directed to landfill by means of the transfer station which is part of the CWCSA facility. Each of the six participating communities is bil led monthly by CWCSA. In this manner the community controls the disposition of their household refuse. All others delivering waste for disposal are treated in a like manner however at a somewhat higher disposal charge.

The CWCSA superintendent, Virgil L. Eller, fully conversant with the residential areas served by the collection trucks, selected vehicles whose routes would provide refuse for this characteriza­tion program which would be representative of the differing socio-economic concentrations within

•

the six communities. It was initially expected to sort a small collec­

tion load (approximately five tons) during each first and second plant operating shift. In this man-

,

ner, ten modest size truck loads, totalling some 50

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TIFFWGMU..-11\...,15'0, !IoTA.llON

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�P"--�"""'--54' = 0600 ---

.

REFUSE CHARACTERIZATION AREA SORTING AND SAMPLING

tons (45 t) would be characterized during the week from the collection area divided into ten sections.

Circumstances at the time were such that only five truck loads were sorted during that week-one each day. These loads were larger than anticipated except for the last day, and there was no significant rainfall during the program week.

Pounds Kilograms

Monday August 27 12,200 5,550 Tuesday August 28 22,900 10,400 Wednesday August 29 14,500 6,600 Thursday August 30 11,000 5,000 Friday August 31 5,200 2,370

Total 65,800 29,920

The forms developed for recording the field data are illustrated in:

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FIG. 2

224

Chart 1 - Sorting Chart 2 - Laboratory Specimen Sampling Chart 3 - Collection Truck Information These forms were found to be satisfactory and

expeditious; however, some improvement can be made.

FACI LlTIES FOR SORTING AND SAMPLING

The maintenance shop located adjacent to the entrance of the enclosed plant tipping floor was cleared and cleaned for the sorting operation. The well lit and ventilated repair shop is adjacent to the transfer station compactor receiving hoppers. These facilities are located at the rear wall of tha tipping floor, opposite the refuse receiving pit (Fig. 2).

After being weighed, the selected collection truck would deposit its load in the center of the maintenance shop floor. The four sorting crew members would circle the deposited load, Fig. 3, while pulling one or two 44 gallon (0. 19 m3) rug· ged plastic drums mounted on casters. Each, drum was designated to receive one of the specific refuse constituents. As the crew member circled the ref­use load he would pick·up and deposit into his drum(s) its assigned constituent. When the drums were filled, he would wheel them to a platform scale (leased for this purpose), leave them, draw emptied drum(s), and repeat the procedure. Those

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,

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constituents of greatest abundance were usually first addressed. As the crew members circled and picked, the materials beneath became exposed for the next crew member following around picking different constituents. The materials considered oversize or bulky such as bicycles, tires, auto mufflers, mattresses, etc. were pulled out for clas· sification separately and photographed (Fig. 5 ). All jugs, jars, bottles, etc., which seemed to con­tain material, were arbitrarily deemed to be hazard­ous, and therefore were accumulated unopened for disposal.

The direct reading (500 lb-� lb graduations) ,

(227lCg) platform scale was located close to the repair shop door leading to the transfer station receiving hoppers. Ten 32 gal (0. 14 m3) heavy plastic drums (with 4 mil plastic liners) for the daily laboratory samples, Fig. 4, were located along the wall close to the door to the transfer station and in close proximity to the platform scale.

The arrangement of the facilities in the (main­tenance shop) refuse sorting-sampling area is illus­trated in Fig. 2. The 32 ft X 54 ft (9. 8 X 16.6 m) room easily accommodated the largest 22,900 lb (10,400 kg) load characterized.

The crew chief and his helper weighed the fllied sorting drums and recorded the weights (tare weights of the empty drums were determined initially). He also seleCted pieces from the contents in the sorting drum which he considered representa-

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FIG. 3

225

CONoeR

K. f'lc(;ce

>A TE �n�/7� _.

liME ti: 10 1\111

CATEGORIES

I. HE WSPRINT

1. OlllEA PAPER

1. DIAPERS

<to TEXTILES/CARMENTS

s. pLAnlC (fILMI

6. pLAnlC (AlGID)

1. FOOD WASTE

•. wDon •

9, YARO WASTE

10. SWEEPING)

11. FERROUS

12. ALUMINUM

13. NON fEHHOUS

14. GLASS IS. BHICK

16. auw

CENTRAL WAVNE COUNTV SAHITA liON AUlilORITY

RAW REFUSE CHARACTERIZA liON SAMPLINC (CAl)

TRUCK IDENT. IN�9 WA.STE SOURCE - (I

TAuCK GROSS WT. 4�.MUUn tRUCK �jET Wi. n �UOO -�-

P�R-TOTAL

CENT WEIGm 100 n73�

9 '"" 15 57�7

1 275

5 1 !l 4 166 2 < 'J.

4 787 2 ) .

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J Jl2!! fI 11 0 Ii)

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BARREL NO. (NET WEIGHT)

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HEMARKS, 'AJJ 16U to calchorlc:; I - 10 to l'ompensalc f'lr 1111) i :..lu,·c IIISS.

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TUTAI. /),\)'S ToNNAt:E: T1tUCK NET \lUCHT: ll�(JU ,/

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PACE L Of _-.!L_

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55 80 21. 3U

47 45 ..QQ.. .li 22 24 27

25 )) IS 41 49 52 '11

40 12 104 68

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SUI<TEIJ TOTAL WI', , l:!.7V) h AS:;m'IEII Till S 1:-' NtJ!STUIi!·. 1.1I�;�1 MW l.JI\!;j IHl I FOHN Ftll< AJ.L CATI';WKl ES 01 - n IU • IJIFFEI(ENCE' 11}1 II

CHART 1 SORTING

, CENTRAL WAVNE COUNTY SAtHTATIOH AUTHONITY

RAW REFUSE CHARACTERIZATION SAMPLING (CoAl)

• LAB SPECIMENS R. HcGt!t!

, . �/28/79 TRUCK 10fNT. [N-I.9 WAST t SOURCE ' ; L"r - (I 11 y

' .. 8:10 AM TRUCIC GROSS WT. 49,8001 TRUCIC Nfl WT. 22.�IIU� ,

CATE- OATE 11,0 ANALYSIS A$II ANALYSIS HEAT CONTENT , BAGGED ,

GORy LA. CATEGORIES WT TEST • TEST •

WT. REeD IUENT 10EIH 10ENT I WJ DATE lila OAlE ASIt

I. NEWSPRINT I � 9/4/79 2. OTHER PAPER 1) 9/I./7� 1. DIAPERS 1 9/4/79 •• TEXTllES/GARMEHTS , 9/4/79 .

S. PLASTIC (FILM) () �/4/79 6. P LASTIC (RIGID) 8 �/4/79 7. FOOD WAHE ..l. ' "I/7� I. WOOD I ' 179 9. YARD WASTE 9,11,179

10. SWEEPINGS 9/4/79

OTHER ,

NOTES, -

1. ASH ANALYSIS; " ASH IS fOR MOISTURE FREE SPECIMENS. ( ""20)

" ASII Of AS-RECEIVED SAMPLE :;; ':\ ASIIMF I - 100 •

2. lilt\' ANALYSIS IS ON A MOISTURE FREE 8ASIS. IttIV FOR AS_RECEIVED SAMPLE:;; IIIIVWF

( I _ ,. H2O ) .

100

CHART 2 LABORATORY SPECIMEN SAMPLING

226

TfSf HHV

DATE

,

n"ly)

PAGE I 0' 1

CENTRAL WAYI.E COUNTY SANITATION AUTHORITY

RAW REFUSE CHARACTERIZATION SANPLWG

COLLECTIOU TRUCK IIIFOPJIATiON

Oa te 8/28179 Time 8: 10 AM Weather Condi tions Cloydy

1. What Co"",unity ---.:.In""k .:..; st""er'--______________ _

2. What Area within Conillunity Inkster � 6eech Daly to John Daly

3. Is it all Res1�ential? -,-,Ye,,-s ___ How Many COCT'JIlercial? ---,: .�'on",e ___ _

4. Anything un:.Js�al about the trash pick-up? --"',�.:..: t.::. tr.::.: es:.::.s _____ __ _

Is there much grass? :"'ore trash :.han '3rass

�. Gross �ei 9ht 49800 Net lie; 9ht 22900 Truck j�umber IN 49

6. Otner Comnents aES�DEnl.;i. COMMlXI!Y - BLACK, :.1i:n: .;SD 3U'E COLL-\R �l!;':Ep. SOT A DEPRESSED .J...i:.£,-\ • . \.'\0 LV· ... :p �!IJPU -';eo"l=' ,

(�!ORE '!'HAX . .;.\'ERAGr A.'!Ol."XT or !'!O!STl'RE IX ru.SH THIS lo'EEK)

Recorded 8y: ,.."

J:.;"--,8",,, r.:...r ___ _ _ _ Orlgln,l s;gneo by:

CHART 3 COLLECTION TRUCK INFORMATION

tive of the constituents observed, and deposited these pieces into the particular laboratory ,sample drum assigned for that constituent. The sorting drum having been weighed (and sampled) was then wheeled to the transfer station compactor receiv­ing hopper, emptied and returned to the platform scale area for retrieval and reuse by the sorting crew.

There were so few containers isolated as having hazardous waste(s) that an accounting of them was consisdered of no consequence.

The arrangement of the plant facilities permit­ted the characterization program to operate with virtually no interference or encumberance of normal plant operations. Utilizing the transfer station facility avoided the need to cross the truck entrance and the tipping floor to deposit the sorted material into the refuse pit at the far side. Not only was encumbrance and traffic interference avoided, but turn around time for the sorting crew

was reduced and potential hazards to them mini­mized.

The sorting-sampling program of five truck loads (+ 32 tons total) (29 t) of material was deemed to be representative of the 484 truck loads (7.5 tons average) (6. 8 t) received during this period although some of the refuse loads were of non-residential wastes.

LABORATORY SAMPLES

The objectives and procedure for obtaining representative constituent samples for laboratory analysis were to randomly select from each truck load approximately 3 fe (0.09 m 3) of that specific material. By withdrawing and accumula­ting small samples from each sorting drum this procedure for obtaining the laboratory sample(s) provided five daily composite samples of each of the ten combustible categories for a total of 50

227

laboratory samples. The weight of the 50 samples obtained for laboratory analyses totaled 923 Ib (419 kg).

Potential bias was considered minimized since some material was selected, at random from each sorting drum by the crew chief, for five truck loads of differing size, each from a different sec­tion of the community.

At the end of each day of sorting and sampling, each of the ten plastic bags with the constituent samples for the laboratory were securely sealed. Each sealed bag was then placed in another 4 mil plastic bag, sealed, and labeled indicating the con­stituent therein, weight of sample, and date as­sembled. This double bagged and sealed sample was then placed into a corrugated box, sealed with plastic tape,labeled and stored. The boxed labora­tory samples were all logged into the laboratory within a week after completion of field sampling.

REFUSE LOADS - GROSS/NET WEIGHTS

The CWCSA plant scale operator provided both the gross and net weights of each load delivered to the sorting area. The demographic information, Chart 3 , was provided by the plant superintendent, Virgil Eller.

The sum total net weights of the sorting drums was less each day than the net truck load delivered . The difference in weight was attributed to the moisture loss during exposure and handling during the day-long sorting activity. Although this differ­ence in weight was small (0.3-2.5 percent) for the

five loads, it was distributed among the consti­tuents in the data summary sheets in accordance· with an assumed propensity for the constituent to pick-up or lose moisture.

DATA SUMMARIES

The field and laboratory data obtained and the correlations prepared resulted in 38 charts and tables. These have been synthesized into the sum­mary tables and charts in this report. However, requests for more specific information will be accommodated by the authors.

CONSTITUENT MAKE-UP OF REFUSE

The constituent make-up of the refuse for each of the five days and their composite averages are shown in Table 1 and Table 2. These data reflect the "as-sorted" as well as the "adjusted" (moisture distributed) weights discussed previously:

So that correlations and extrapolations might readily be made, the data is also presented to re­flect constituent mix on a "yard waste-free" basis. The yard waste encountered during this period was essentially grass clippings. Presenting the data in this manner provides an indication of the refuse make-up which might be encountered during the months of little yard-activity . This information is particularly signi£i.cant in view of the high percent­age of yard waste encountered in the refuse and its very high moisture content. The impact of yard waste on the character of the refuse is dramatic-

TABLE 1 DAILY REFUSE CONSTITUENT WEIGHT DISTRIBUTION

CENTRAL WAYNE COUNTY SANlTATION AUTHORITY RAW RJ::FU51:: CHARACTERIZATlON SAMPLlNr. AND ANALYSES

Refuse Sort lng Program AugUSt 21 thru 31, 1979 Total Set \.rl:! 19ht: 65,800 pounds· Trucks: OH 452. tN-49, :-lA-20, WE-65, 8-234

AUluse 27 AutuS[ 28 Ausust 29 AUlust )0 AUiust 31 Weight. I Weight Weight, I Weight Weight, I Weight Weight. , Weight Wdaht, I Weight

Constituent � -'- As Sorted -'- As Sorted -'- As Sorted -'- As Sorted -'-

I. Newspr int 822 6.84 1,961 8. &2 1,250 8.64 853 7.94 402 7.96 2. Other paper 2,967 24.7 5,787 25.5 3,373 23.3 2,098 19.6 1,447 28.6 ). Diapers 156 1.30 275 1.20 152 1.05 108 1.01 4 0.09 4. Text iles/garments 219 1.82 I, 091 4.80 797 5.51 425 3.95 80 1. 59

5. PlastiCS, f11m 277 2.31 866 3.80 545 3.77 259 2.40 85 1.69 6. Plastics, rl.gl.d 196 1. 63 528 2.31 368 2.54 256 2.37 86 1. 70 7. Food waste 496 4.13 787 3.45 149 1.03 554 5.15 17 0.35 8. Wood 66 0.56 340 1. 50 143 0.99 143 1.32 )2 0.64

9. Yard wastl!: 5,444 45.3 8,203 36.1 5,2).2 )6.2 4.866 45.4 2,034 40.2 10. Sweepings 420 3.50 257 1.12 341 2.36 190 1.76 115 2.29 II. Ferrous 240 2.00 690 3.02 579 4.00 364 3.39 140 2.78 12. Aluminum 16 0.14 J7 0.16 89 0.63 27 0.25

I). Nonferrous 35 0.29 108 0.47 97 0.68 69 0.64 14. Glass 455 3.79 67) 2.95 494 3.42 276 2.56 285 5.64 15. Brick 19 0.16 152 0.67 724 5.02 )0 0.28 16. OBW 182 1.53 984 4.33 125 0.':\6 212 1.98 327 6.47

Total 12,010 100.0 22,739 100.0 14,458 100.0 10,730 100.0 5,054 100.0 Truck Net Weight 12,200 22,900 14,500 ll,OOO 5,200 Difference 190 I. 56 161 0.70 42 0.29 270 2.46 146 2.18

* one pound (D) • 0.4536 kilograms (kg)

228

TABLE 2 CONSTITUENT WEIGHT DISTRIBUTION - 5 DAY COMPOSITE

CE:\,TRAL �,W�E cou;-.:n SA;'; IT ATlON AUTHOR tTY "'" REFUSE CHARACTERIZAT10:-l SA}IPLlNG A:-ID ANALYSES

Refuse Sorting Program AuguSt 27 thru 31, 1979

Composite of 5 Days Collect ion Total Net '''eight: 65,800 pounds·

Adjusted [0< �Io�sturc Loss �l:ring Sam�ling Excluding. Yard Waste Weight, # Weight Weight, 1/ \,'eight \"'eight, II We igh t Weight, D Weight Weight. N Weight

Constituent Adjusted Adjusted t\djusted % Adjusted % Ad lusted %

I . Newspr int 5,288 8. 14 5,322 8.09 5,322 9. 12 5.322 13.4 5.322 16.4

2. Other paper 15,612 24. 1 15,726 23.9 15,726 26.9 15,726 39.5 15,726 48.5

3. Diapers 695 1.07 835 1. 27 815 l. 4) 835 2.09 835 2.58

, . Textiles/garments 2,612 '.02 2,640 4.01 2,640 4.52 2,640 6.62 2.640 8. 14

5. Plastics, fUm 2,032 3. 13 2,089 ). 1 7 2,089 3 . 5 8 2,089 5.24 2,1.I89 6.44 6. Plasti cs, r is id 1,434 2 . 2 1 1,449 2.20 1 ,449 2.48 1,l.l.9 3.6t. 1,l.49 l..47 7 . Food waste 2,003 3.0& 2,19l. 3.31 2. 19l. 3.76 l, 194 5.50 2.19l. 6. 77 8. Wood 72' 1.11 755 1. I ) 755 1. 29 755 1. 89 755 2. 33 9. Yard waste 25,779 39.7 25,940 39.l. 2).940 44.l. 10. Sweepings I. )2) 2.04 I ,42 I 2. 16 1,l.21 2.43 j ,421 3.56 1,421 l..38 II. Ferrous 2,013 3. 10 2,013 3.06 2, a 13 5.05 12 . Aluminum 169 0.26 169 0.26 169 0.l.2

I 3. Nonferrous 309 0.48 309 0.47 309 0.78 ". Glass 2. 183 3.36 2. 183 3. 32 2 , 183 5.l.8 I 5 . Brick 925 I . 42 925 l. l. I 925 2. 32 I 6. 080 1,830 2.82 1.830 2.78 I ,830 l. . 59

Total 64,991 100.0 65,800 100.0 58,372 100.0 39,860 100.0 32,431 100.0

Difference 809 1.2 7,428 11. 3 25.9l.0 39.4 25.940 18.7

• onp pound (I) • O.l.�3h ktlogram� (kg)

FIG.4

229

FIG.5

it can be + 40 percent of the total weight or + 48 percent of the combustible portion, and can aver­age + 70 percent moisture.

Similarly, data summaries were structured with and without the discernible noncombustibles

,

(constituents 11 through 16) so as to readily reflect the make-up of the organic/combustible fraction of refuse - as if subjected to ,a highly selective and efficient form of front-end or source separation program. The data in Table 2 are especially in­formative. It indicates that for the 5 day com­posite, the noncombustible constituents - 11 thru 16 - were only 11.3 percent of the total refuse (as discarded), and 18.7 percent when reported on a yard waste-free basis.

The Michigan "bottle bill" was in effect for some six months when this refuse sorting program was undertaken. Some reflection in the constituent mix data resulting from this legislation was ex­pected. Although actual comparative data is not available since this was the first major attempt at refuse characterization by CWCSA, the plant operators and management had observed some reduction in the quantities of glass, steel and aluminum cans in the furnace residue and grate siftings . .. attempts at absolute quantification at this time would be misleading.

The weight percentages of ferrous, aluminum

and glass do appear to be lower than the values usually reported in the literature, even on a yard waste-free basis [6] . Perhaps the values of CWCSA are closer to reality or already reflect the impact of the Michigan bottle bill.

Although only consisdered to be a coarse check on the ferrous fraction, the quantity of ferrous material magnetically separated at the residue landfill by a secondary materials dealer may be of interest. In the six months prior to the Michigan "bottle bill" the ferrous weight reported (monthly) by the reclaimer relative to the refuse consumed at the plant, averaged 6.95 percent. During the six

months following passage of the bill, (January to July 1979) the ferrous weight reported averaged 5.76 percent. However, during the next three

months, July thru September 1979, the ferrous weight reported averaged 6.07 percent (August was 6. 81 percent) of the refuse consumed in the CWCSA furnaces. These weights are some 2/3 of that generally reported in the literature. The weights reported by the reclaimer are gross weights of the material picked-up by his crane magnet and include entrained wet ash/siftings/fly ash as well. as other constituents. Payment to CWCSA for, recovered metal is in effect based on 50 percent of the weight reclaimed at the landfill. Therefore the net ferrous values are considered to be 2.5 to 3.5

230

percent of the refuse consumed. These net values are approximately 1/3 of that generally reported elsewhere [6] . The sorting program data reported herein corresponds closely to this range of net values.

Based on the above analysis it would appear that the Michigan "bottle bill" has had an indiscernible impact on the ferrous quantities received at CWCSA facility during the 0 + 9 month influence.

Several other items draw focus; the very low percentages of food waste (less than one-third the values usually reported), the low percen tages of aluminum, nonferrous and particularly glass (less than � - the bottle bill?), the high percentage (+ % more) of plastics. So much of the textiles, garments and footwear are composed (at least in part) of synthetic materials that categorizing them expendiently was taxing. The weight percent for this constituent was generally higher (2x) than expected.

As mentioned previously, by programmed intent, collection vehicles were selected for refuse load characterization based on knowledge of the residential areas they serve. In this manner the data was to reflect the variation in waste character based on socio-economic considerations. The tabulations in Table 1 do not reveal marked dif­ferences in constituent concentrations. There was only modest variation from locale to locale in the weight percent of the constituent mix.

LABORATORY ANALYSIS PROGRAM

At the outset it was agreed that this program would address each waste constituent separately and form composites of the laboratory parameter analyses to characterize the refuse. For the data to have credibility the number, size and representa­tiveness of the laboratory samples were elements of prime concern.

Laboratory analyses were made only for the parameters of fundamental interest; moisture, ash (inerts), calorific value, sulfur, total chlorine and water soluble chlorides. The analytical procedures and methods closely adhered to by the Gilbert laboratory chemists were those currently pro­mulgated as standards by ASTM E-38.01.

Analyses were conducted on only constituents 1-10 which were designated as combustible cate­gories and would yield data considered to be of significance. Constituent categories 11-16 were all considered to be essentially noncombustible, con­tributing little other than ash (reSidue) when charged into a furnace. Nevertheless, it was recog­nized that some surface moisture and some com­bustible are present in these items, such as, labels, decals and coatings (paints) on the cans and bottles, and possibly some organic residues within the containers, and that "some" oxidation of the container materials would also take place. How­ever, the weight percent of the lot was small rei a-

TABLE 3 COMBUSTIBLE CONSTITUENTS MOISTURE DISTRIBUTION - DAILY AND COMPOSITE

CENTRAL WAYNE COUNTY SANITATION AUTHORITY RAW REFUSE CHARACTERIZATION SAHPLING AND ANALYSES (GAl)

AUGUST 27 thru 31, 1979

Adjusted 5 Day Total Composite Total f2Ynd� MQi�tu[e CQot[ibuti20 Moi s ture Average Weight Day Day Day Day Day Total Hoi sture

Constituent POlJnds� I 2 3 4 5 Pounds .. I . Newsprint 5322 108 307 287 133 49.8 885 16.6

2 . Other paper 15726 784 1851 736 399 296 4066 25.9

3. Diapers 836 125 180 92.5 103 13.8 514 61.6

4. Textiles/ garments 2640 12.3 258 126 57.4 6.29 460 17.4

5. Plastics, film 2089 75.7 170 127 70.3 27.5 470 22.5

6. Plastics, rigi.d 1449 22.2 20.4 9.90 18.7 3.97 75 5.18

7. Food waste 2194 441 695 118 532 46.9 1833 83.6

8. Wood 755 5 . 19 59.3 18.4 25.7 5.73 I 14 15. 1

9 . Yard waste 25940 3803 6143 3600 3702 1339 18587 71.6

10. Sweevillgs 1421 230 127 179 85.4 47.4 669 47.1

Tolal 58372 5606 9811 5294 5126 1836 27673 47.4

Weight in Puuuds Collecled 11253 20256 12392 loon 4448 58372

�bisture - percent (X) 49.8 48.4 42.7 51.1 41.3 47.4

* pound = 0.4536 kilograms (kg)

231

tive to the whole and the weight fraction of the combustible portion thereof would be so small that the complexities of specific laboratory analyses could not be justified.

MO ISTU R E

The daily and composite moisture data for the 1 0 "combustible" constituents are displayed in Table 3. The high moisture value(s) for the refuse is attributed principally to the relatively high weight percent of the (high moisture content) yard waste constituent. The high moisture values for diaper-like materials and food wastes are as expected. However, the high moisture (+ 22 per­cent), for plastic filin was not anticipated and can be attributed to the extensive use of plastic bags as the containment for the large quantity of very wet grass clippings encountered. Therefore, this moisture should be considered as essentially sur­face (free) moisture rather than inherent moisture.

All of these values would be moderated some­what if tabulated on the weight basis of all 1 6 constituents (42. 1 percent moisture versus 47.4 percent). On a yard waste-free basis the 5 -day composite values are 28 percent moisture for the combustible portion and would be 22. 8 percent moisture based on the weight of all 1 6 constituents.

ASH

A similar tabulation for the ash (dry) inherent in the combustible materials is displayed in Table 4. The high ash content for sweepings was not surprising and should be of little concern since the quantity of sweepings is so small. The ash content in plastic film and in yard waste was higher than expected. The data reported herein should not be considered·as absolute values for each of the con­stituents, e.g., for plastic film there must have been not only moisture adhering to the film surface, but also dirt in one form or another, grass clippings and other small particle size items whose weight is quite high relative to the very light weight of the plastic filin. Overall, the 5 day composite ash content of the combustible constituents, 8.75 per­cent (diy-basis), can be considered modest. The ash content of the composite including the noncom­bustibles is 1 5 .4 percent, as-received basis, and is 22 percent when reported as yard waste-free.

CA LO R I F IC V A L U E - HHV

Heating value on a moisture and ash free (M.A.F.) basis is reported in Table 5 for each constituent as well as its daily contribution. The 5-day composite M.A.F. heating value for the

TABLE 4 ASH I N COMBUSTI BLE - DAI LY AND COMPOSITE

CENTRAL WAYNE COUNTY SANITATION AUTHORITY RAW REFUSE CHARACTERIZATION SAMPLING AND ANALYSES

AUGUST 27 thru 31 . 1980

Adj us ted 5 Day Total Composite Tola I Pounds Ash Co�t r i bution Dry-Ba s i s Ash Average We i ght Day Day Day Day Day To ta l Dry Ash

Cons t i tuent Pounds* 1 2 3 4 5 Pounds " --I . Newsprint 4437 l l.6 25.8 11.8 8.55 2.36 62.1 1. 40

2. Olher paper 1 1660 135 156 138 I I I 6 1 .4 601 5. 15

3 . Diapers 322 I . 51 3.78 1.02 0.99 0.34 7.64 2.38

4. '('ext i L es/garments 2 1 80 4.85 33 . 8 23.5 7.82 4.80 74.8 3 . 43

S. P l a s t i c s , f i lm 1619 20.5 104 54. 7 10.6 9.66 200 12.4

6. P l a s t i cs J r i g i d 1374 10.9 56.6 10.8 7.79 1. 5 1 87.6 6.38

7. food wa ste 361 6.77 10.0 3.98 5.60 0.70 27 . I 7.51

8. Wood 64 1 2.25 18.4 I . 51 3 . 6 1 0.40 26.2 4 . 09

9 . Volrtl wal:ile 73S3 312 378 299 210 149 1348 I ft . 3

10. Sweep i ngs 752 55 . 6 51 . 3 45.7 55.2 44. I 252 33.5

Tot.a l 30699 561 8JK 590 421 274 2686 8 . 75

Dry Wd ghl Pounds Co I lec:led 561.8 101.47 7099 4896 26 12 30699

Ash-Dry Basis - percent (%) 9.97 K.02 8 . 31 8.60 10.5 K.75 (Wt . Ash/Wt . lbs collected)

• pound = 0 . 4536 k i lograms (kg)

232

TABLE 5 BTU IN COMBUSTIBLE (M .A.F . l - DAILY AND COMPOSITE

CENTRAL WAYNE COUNTY SANITATION AUTllOHITY RAIl REFUSE CHARACTERIZATION SANPLING AND ANALYSES

AUGUST 27 thru 3 1 , 1 9 7 9

Tota l Ho i s ture Compo s i te Ash-Free

x 1 05' S-Dar Average

Adj us ted BTU Con t r i bu t i on Ho i st u re-Ash-Free BTU To t a l Hoist/Ash Weight Day Day Day Day Day

B��U /�0

5 Free

Consl i tuent Pounds * I 2 __ 3 __ 4 __ 5 __ BTU/lbs."

---_.- ---- ---- ----

I . Newspr i nt 4375 6 1 . 749 1 4 2 . 2 1 2 8 1 . 958 6 3 . 046 3 0 . 869 379 . 834 8682

2 . Other paper 1 1 059 1 7 4 . 280 3 1 1 . 72 1 2 32 . 7 6 1 1 36 . 250 9 1 . 800 946 . 8 1 2 8562

3 . Diapers 3 1 4 5 . 836 9 . 648 5 . 2 78 4 . 503 1 . 09 3 26 . 358 8394

4 . Tex t i l es / ga rments 2 105 18 940 7 6 . 345 59 . 68 3 32 . 231 6 . 85 9 1 9 4 . 058 9 2 1 9

5 . P l a s t i c s , f ioer 1 4 1 9 2 9 . 293 1 1 8 . 1 5 8 , 9 . 398 34 . 956 9 . 432 2 5 1 . 237 1 7 705

6 . P L a s t i c s , r i g i d 1 286 30 . 383 78 . 360 64 . 1 4 0 42 . 272 1 5 . 950 23 1 . 1 0 5 1 79 7 1

7 . Fooft wasle 334 . 029 1 0 . 248 3 . 032 6 . 930 0 . 67 4 29 . 9 1 3 8956

8 . Wooel 6 1 5 . 4 7 1 24 . 95 9 1 3 . 04 1 1 0 . 95 8 2 . 844 5 7 . 27 3 9 3 1 3

9 . Ya rd waste 6005 122 03 1 1 56 5 1 7 1 20 . 006 9 6 . 844 5 1 . 595 546 . 993 9 109

1 0 . Swt"ep i ogs 500 1 4 . 5 7 5 1 0 . 1 , 2 1 1 . 394 5 . 92, 3 . 869 4 5 . 9 1 5 9 1 83

To t a l 280 1 2 4 7 1 . 5 87 938 . 320 650 69 1 433 . 9 1 5 2 1 4 985 2709 . 498 9673

Mo i s l ure-Ash-t'ree o r Comhus t i h l es We i gh t Poullds 5084 9609 6509 4475 2138 280 1 2

HHV - BTU/lbs . " 9276 976, 9 9 9 7 9696 9 1 9 5 9 6 7 3

* pound "" 0 . 4536 k t l ograms (kg) STU / l b s . z 2 . 32 kiloJoules/ki logram (kJ/kg)

TABLE 6 COM PARATIVE SUMMARY - M OISTURE, ASH, HHV

CENTRAL WAYNE COUNTY SANITATION AUTHORITY RAW IiASTE CHARACTERIZATION SAMPLING AND ANALYS I S

AUGUST 2 7 thru 31 , 1 9 7 9

August 27 5 -0ay Compo s i t e As Received As Received Yard Waste-Free

Moisture - %

Ash - as received - % Ash - dry basis - %

HHV - as received - Btu/ Ibs . " HHV - dry basis - B t u / lbs . HHV - M . A . F . - B t u / l b s .

T o t a l Chlorine

H2

0 Chloride

t. r.hlorine (organic)

Sulfur

Note :

- %

- %

- %

- %

A l l Const ituents

4 5 . 9

12 . 4 22 . 9

386fi 7146 9276

0 . 1 7 1

0 . 082

0 . 089

0 . 058

All Const i tuents

42 . 1

15 . 4 26 . 5

4118 7 1 12

9689

See Tables 7 and 8 for more specific data on chlorine and sulfur

" STU/ lbs . a 2 . 32 kiloJoule s / kilogram (kJ/kg)

233

Combust ible Al l Constituents Constituents

22 . 8 28 . 0

22 . 0 4 . 13 28 . 5 5 . 73

5425 6668 7027 9263 9826 9826

combustible constituents is 9673 Btu/lb (22,480 kJ/kg) and on a yard waste-free basis the M.A.F. heating value is 9826 Btu/lb (22,836 kJ/kg). This value is somewhat higher than that generally reported by others. The M .A.F. heating value is a convenient base from which transformations can be readily made to provide values reflecting speci­fic entrained and inherent moisture and ash values encoun tered.

The summary tabulations of the basic thermo­chemical parametric data on an as-received and yard waste-free basis are provided in Table 6 .

SU L F U R AND C H LO RIN E

In view of the intense interest and concern regarding potential chemical attack, replicate analyses were made for sulfur and chlorides on the samples obtained of the synthetic materials in addition to the normal determinations for these parameters on the other constituents. Table 7 and Table 8 summarize the data obtained.

The very low sulfur values reported herein, were as expected.

In an effort to relate the chlorine derivatives that may be deleterious in a combustion system, it has been generally postulated that the chlorine atoms which are insoluble in water are those of

particular concern [8] . The premise being that at the temperatures usually encountered in a furnace, the insoluble forms of chlorine will vaporize and therefore have the oPRortunity to readily combine with other constituents and become chemically aggressive.

The laboratory investigation of the chlorine bearing constituents focused on identifying the organic or insoluble chlorine(s) of concern. This was accomplished by deducting from the deter­mined total chlorine values the values for the water soluble chlorides (H2 0 soluble C C); the resulting arithmetic difference being the organic chlo'rine. These values are all reported in Table 7. However, a qualification is necessary when assess­ing this data ; not all organic chlorines are insoluble in water and not all inorganic chlorides are soluble in water. Therefore , the values in Table 7 can only be considered indicative, not absolute . Normally, the data appearing in the literature are the total chlorine values rather than the arithmetic differ­ences just discussed.

The full significance and impact of the above is apparent when examining the data reported in Table 7 for textiles/garments (8-29-79). The total chlorine is reported to be 3 .78 percent and the water soluble chloride at 3 .73 percent. The calcu­lated difference of 0.05 percent is the organic

TABLE 7 SULFUR A N D CHLORINE IN TEX TILE A N D PLASTIC CONSTITUEN TS

Constituent

Date 8-27-79 Text iles/ garment s Plast ic s , f i lm Plas t i c s , rigid

Date 8-28-79 Textiles/garments Plast ics , film Plast ic s , rigid

Date 8-29-79 Text iles/ garment s Plast i c s , f ilm Plast ies , rigid

Date 8-30-79 Text tIes /garment s P l as t ic s , f ilm Plast i c s , rigid

Date 8-3 1-79 Textiles/ garment s Plast ic s , Plast ics ,

Not e : -

f ilm rigid

CENTRAL WAYNE COUNTY SANITATION AUTHORITY RAW REFUSE CHARACTERIZATION SAMPLING AND ANALYSES

AUGUST 27 thru 3 1 , 1 9 7 9

As-Received Drx-Basis H

2O Total H

2O Total

5 Sol . C 1 Cl 5 Sol . C l C l 5 -_% - -_% - _%- % _%_- % _%-

<0 . 007 0 . 026 2 . 3 3 < 0 . 00 7 0 . 028 2 . 4 7 < 0 . 00 7 < 0 . 006 0 . 1 2 2 0 . 20 1 <0 . 008 0 . 1 6 5 0 . 2 7 2 < 0 . 009

0 . 38 0 . 1 4 3 1 . 1 5 0 . 4 3 0 . 1 6 1 1 . 2 9 0 . 4 6

0 . 030 0 . 146 0 , 295 0 . 039 0 . 1 90 0 . 385 0 . 04 1 <0 . 0 1 0 . 1 97 0 . 282 < 0 . 0 1 0 . 244 0 . 35 0 < 0 . 0 1 <0 . 0 1 0 . 099 0 . 290 < 0 . 0 1 0 . 1 0 3 0 . 303 < 0 . 0 1

< 0 . 0 1 3 . 7 3 3 . 78 <0 . 0 1 4 , 4 3 4 . 49 < 0 . 0 1 < 0 . 0 1 0 . 265 0 . 2 7 7 < 0 . 0 1 0 . 345 0 . 360 < 0 . 01 <0 . 0 1 0 . 299 0 . 374 < 0 . 0 1 0 . 30 7 0 . 384 <0 . 0 1

0 . 0 6 1 0 . 095 0 . 098 0 . 070 0 . 109 0 . 1 1 3 0 . 07 1 <0 . 0 1 0 . 10 1 0 . 396 < 0 . 0 1 0 . 1 35 0 . 530 < 0 . 0 1 < 0 . 0 1 0 . 1 54 0 . 47 7 < 0 . 0 1 0 . 166 0 , 5 1 4 < 0 . 0 1

0 . 02 2 0 . 058 0 . 32 2 0 . 024 0 . 063 0 . 348 0 . 02 6 0 . 060 0 . 329 0 . 364 0 . 08 3 0 . 4 5 7 0 . 506 0 . 096 0 . 074 0 , 032 0 . 086 0 . 07 7 0 . 034 0 . 090 0 . 078

Total chlorine minus water soluble chlorides . ( H20 Sol . C l-

) :: organic chlorine

234

Moisture and Ash-Free H

2 O Total

Sol . C l C l _%_" - _X-

'0 . 02 9 2 . 5 3 0 . 1 8 2 0 . 30 1 0 . 1 7 1 1 . 37

0 . 198 0 . 4 0 1 0 . 2 8 6 0 . 4 1 0 0 . 1 1 6 0 . 34 1

4 . 59 4 . 65 0 . 397 0 . 4 14 0 . 3 1 7 0 . 396

0 . 1 1 1 0 . 1 1 5 0 . 1 4 2 0 . 558 0 . 1 7 2 0 . 5 3 1

0 . 06 7 0 . 37 1 0 . 530 0 . 58 6 0 . 035 0 . 092

Total C 1

Minus H2

0 Sol . C I . %

2 . 50 0 . 1 1 9 1 . 20

0 . 203 0 . 1 24 0 . 2 2 5

0 . 06 0 . 0 1 7 0 . 07 9

0 . 004 0 . 4 1 6 0 . 359

0 . 304 0 . 05 6 0 . 05 7

chlorine. Although some of the as-determined values reported may seem high, it must be recog­nized that it is the difference in these values which should be used in assessing the degree of possible chemical aggressiveness. Inspection of the low as­determined values in Table 7 would reveal arith­metic differences (organic chlorine) which are much greater than that which appear at first glance. This is reflected in the last column of tabulated data reported on a moisture and ash­free basis_

The sulfur and chlorine value determinations for all 10 combustible constituents were conduct­ed only on the laboratory samples obtained on August 27, 1979. These are reported in Table 8 on an as-received basis and are cast to reflect the composite weighted averages, all of which are considered relatively low.

SUMMARY AND CONCLUSIONS

A program was undertaken to characterize the once per week collected as-discarded refuse from the residential areas served, divided into five socio­economic sectors.

During the 5 days, August 27 through August 31, 1979, five truck loads (one each day), totalling 65, 800 Ib (29,920 kg), or 32.9 tons (29.9 t) of packer truck refuse was sorted into 16 constituent

categories. The smallest refuse load characterized was 5 200 Ib (2,370 kg), and the largest load was 22,900 Ib (10,400 kg).

With a well planned and managed program, a

suitably equipped, well motivated six or seven man

team, functioning in an enclosed, well lighted and

ventilated environment, it is practical to sort and

sample loads of 5-6 tons of as-discarded m unicipal

refuse in a normal 8 hr shift. Samples for laboratory analyses were taken

each day of the 10 constituent categories con­sidered combustible. These samples taken at random provided the laboratory with 5 0 sealed and boxed samples weighing approximately 1000 lb (454 kg). Each box contained approximately 3 ft3 (0.09 m3 ) of materiaL

The analysis parameters investigated in the laboratory were: moisture, ash, calorific value, sulfur, total chlorine and water soluble chlorides. The analysts adhered to the methods and pro­cedures currently promulgated as standards by ASTM E-38.0l .

The analytical data is presented for the samples obtained each day as well as a 5 day composite. The data summaries are tabulated in several formats; as-received, yard waste-free, dry, moisture and ash­free. These data are provided for the combustible portion alone (constituents 1 thru 10) as well as for the total mix of 16 consituents.

TABLE 8 SULFUR AND CHLORINE

CENTRAL WAYNE COUNTY SANITATION AUTHORITY RAW WASTE CHARACTERIZATION SAMPLING AND ANALYSIS

LABORATORY SAMPLES COLLECTED AUGUST 27 , 1979

As Received Adj usted Total Cl Total Sulfur H20 SOL H20 SOL Total Total Minus H2O W('lght Sulfur Con :: r ib . Cl- Cl- Cl Cl SOL. Cl-

Constituent ?ounds* % Pounds % Pounds % Pounds %

1) Newsprint 829 0 . 1 0 0 . 829 0 . 036 0 . 298 0 . 037 0 . 307 0 . 001 2) Other paper 2 , 981 0 . 10 2 . 981 0 . 090 2 . 683 0 . 193 5 . 753 0 . 103 3) Diapers 191 0 . 02 0 . 038 0 . 098 0 . 187 0 . 101 0 . 193 0 . 003 4) Textile/garments 222 < 0 . 007 0 . 026 0 . 058 2 . 33 5 . 173 2 . 304 5) Plast ic , f ilm 292 <0. 006 0 . 122 0 . 356 0 . 201 0 . 587 0 . 07 9 6) Plastic , rigid 202 0 . 38 0 . 768 0 . 143 0 . 289 1 . 15 2 . 32 3 1 . 007 7) Food waste 540 0 . 01 0 . 054 0 . 158 0 . 853 0 . 1 7 7 0 . 956 0 . 019 8) Wood 70 0 . 06 0 . 042 0 . 039 0 . 027 0'. 059 0 . 0413 0 . 02 9) Yard waste 5 ,480 0 . 04 2 . 192 0 . 084 4 . 603 0 . 086 4 . 71 3 0 . 002

10) Sweepings 447 0 . 03 0 . 1341 0 . 145 0 . 648 0 . 178 0 . 796 0 . 033 Total Weights 11 , 253 7 . 0381 10. 002 2 0 . 8423 Weighted Avg. - % 0 . 063 0 . 089 0 . 185 0 . 096%

11) Ferrou� 240 12) Aluminum 16 13) Non Ferrous 35 14) Glass 455 15) Brick 19 16) OBW 182

Total 1 2 , 200 7 . 0381 10 . 002 2 0 . 8423 Weighted Avg. - % 0 . 058 0 . 082 0 . 171 0 . 089

Not e : Sulfur and chlor ine dpterminations for "al1" combustible constituents ( l thru 10) conducted only on laboratory

. samples obtained on August 2 7 , 1 9 7 9 .

• pound = 0 . 4 535 kilograms (kg)

235

The sorting data summaries reveal that the constituent mix of the refuse was relatively uni­form from day to day, regardless of the quantity sorted or the residential source within the com­munity.

The composite parametric data on a yard waste­free basis can be interpreted to be indicative of the refuse make-up during the months of idle yard­activity. These data reveal that the refuse was lower in moisture, lower in ash, and thermally richer than the characteristics usually reported in the literature.

The impact of the yard waste data is significant - this constituent can be + 40 percent of the total refuse weight or + 48 percent of the combustible portion and can average + 70 percent moisture. Although the yard waste quantity could make a significant energy value contribution - some 20 percent - this is completely over-shadowed by the added high moisture burden - 67 percent of the total moisture in the refuse.

The high moisture (+ 22 percent) and high ash (+ 12 percent) in the plastic film can be attributed to its extensive use as the containment of the large quantities of very wet grass clippings; moisture adhering to the film surface as well as many small particle size items whose weight relative to the very light weight of the plastic film could be substantial. An analysis of similar but clean, un­used plastic film would indicate inherent moisture values are usually less than 1 percent and ash values usually less than 5 percent.

The higher calorific value of the refuse can be attributed to the lower metals and glass content and the higher percentage of readily identifiable plastics, + 5 percent. The high calorific value of the combined weight percent of the plastics con­tributes some 17. 8 percent to the total energy value in the refuse.

The CWCSA plant personnel have always felt that the ratio they encounter for the ferrous, glass and aluminum constituents is lower than the values generally reported by others. The weight percent­ages for these constituents determined in the August 1979 refuse sorting program indicate values from one-third to one-half of that generally as­sumed. The ferrous reclamation program at the furnace residue landflll has been yielding data, for years, which indicates the net ferrous fraction to be less than one-half of that reported by others.

The effect (9 months) of the Michigan "bottle bill" on the ferrous and glass weight fraction was not readily discernible. The effect to date, if any, might be gauged as a reduction of less than 1 per-

cent of each of these constituents in th e total mix. This program (at CWCSA) to characterize the

massive quantitites of as-discarded municipal re­fuse in a finite period of time was a formidable undertaking. However, the accomplishment of a rigorous sorting, sampling and analytical activity resulting in data haVing great consistency with virtually no outliers provides the high confidence sought in such information.

It is recognized that this data, as credible as it might be, was generated from sorting and sampling only 1 percent of the total refuse received at the plant during that program week. However, the data does prov\de more information to CWCSA (and others) than previously available. In view of the variability of refuse, the program should be repeated at least seasonally. Some refinement in the procedures and management would also pro­vide broader logistical and demographic informa­tion.

, The success of this undertaking required and received the enthusiastic support and effort of everyone involved, particularly the CWCSA plant personnel. However, it was the perception and confidence of Charlotte Rines and Donald K. Walter of D.O.E. and the support funding they had provided which permitted this characterization activity to take place and is gratefully adknowl­edged.

REFERENCES

[ 1] Carruth, D. E., and Klee, A. J . , "Analysis of Sol id Waste Composition; Statistical Technique to Deter­mine Sample Size," USDHEW, Cinn. 1969.

[ 2] Kaiser, E. R., Zimmer, C., and Kasner, D., "Sampling and Analysis of Sol id Incinerator Refuse and Residue," 1970 National Incinerator Conference, ASME, New York, 1970.

[3] Achinger, W. C., and Danie ls, L. E., " An Evalua­tion of Seven Inci nerators," 1970 National Incinerator Con ference, ASME, New York, 1970.

[4] N iessen, W. R., Chansky, S. H., "The Nature of Refuse," 1970 National Incinerator Con ference, ASME, New York, 1970.

[5] Stephenson, J . W., and Eller, V. L., "The Quest for Incinerator Air Pol lution Control," 1980 Ninth ASME National Waste Processing Conference.

[6] USEPA - Fourth Report to Congress "Resource Recovery and Waste Reduction ," SW-600, 1977.

[7 ] Hollander, H. I., and Kieffer, J . K., "Developing Analytical Procedures for Reproducible Determinations of Thermo-Chemical Characteristics of RDF - An ASTM Program" . 1978 ASME Winter Annual Meet ing.

[ 8] Klumb, D. L., and Hol lander, H. I., " Firing and Co-Firing of Processed Urban Refuse i n Uti l i ty Opera­tions," 1 979 IGT Symposium - New Fuels and Advances in Combustion Tech nology, New Orleans.

236

Key Words

Analysis

Calorific Value

Chlorine

Composition

Ferrous

Sampling

Sulfur

237