United States
Environmental
Protection Agency
Office of Solid Waste    Office of Air      Off ice of Research   EPA/530-SW-87-02TT
and Emergency Response  and Radiation     and Development   June 1987
Washington, DC 20460   Washington, DC 20460  Washington, DC 20460
SEPA
Municipal Waste
Combustion Study
               Recycling of Solid Waste

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                                                 June  1987
       MUNICIPAL WASTE COMBUSTION STUDY:

           RECYCLING OF SOLID WASTE
                 Prepared by:

              Radian Corporation
  3200 East Chapel Hill Road/Progress Center
                P.O. Box 13000
      Research Triangle Park, N.C.  27709
           For Information Contact:

                David Cleverly
          Pollutant Assessment Branch
 Office of Air Quality Planning and Standards
     U.S. Environmental Protection Agency
      Research Triangle Park, N.C.  27711
EPA Contract No, 68-02-4330, Work Assignment 9
         Radian Project No. 239-001-09

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                                  DTSCLAIMER

     This document has been reviewed and ape oved for publication by the
Office of Air and Radiation, U.S. Environme  al Protection Agency.  Approval
does not signify that the contents necessar.iy reflect the views and policies
of the Environmental  Protection Agency, nor does the mention of trade names or
commer  al  products constitute endorsement or recommendation for use.

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                               TABLE OF  CONTENTS
                                                                        Page
CONTENTS	      i
LIST OF TABLES	    i ii
LIST OF FIGURES	     iv
1.0  INTRODUCTION AND SUMMARY	    1-1
2.0  EXTENT OF CURRENT RECYCLING	    2-1
     2.1  RECYCLING IN THE UNITED STATES	    2-1
     2.2  RECYCLING IN OTHER COUNTRIES	    2-4
          2.2.1  Sweden	    2-4
          2.2.2  Norway	    2-5
          2.2.3  Germany	    2 -~5
          2.2.4  Denmark	«    2-7
          2.2.5  Italy	    2-8
          2.2.6  Japan	    2-8
     2.3  REFERENCES	    2-10
3.0  SEPARATION METHODS	    3-1
     3.1  SOURCE SEPARATION	    3-1
          3.1.1  Source Separation Methods	     3-1
          3.1.2  Source Separation Programs At Some Localities	     3-4
     3.2  CENTRALIZED PROCESSING	     3-5
          3.2.1  Description Of Centralized Processing Techniques	     3-6
               3.2.1.1  Separation Techniques For Ferrous Metals	     3-8
               3.2.1.2  Separation Techniques For Nonferrous Metals...     3-8
               3.2.1.3  Separation Techniques For Glass	     3-9

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                                                                         Page
               3.2.1.4  Seoaration Techniques For Paper	     3-9
          3.2.2  Description Of Commercial Centralized Processing
                 Systems 	     3-10
               3.2.2.1  Sorain-Cecchini System	     3-10
               3.2.2.2  Stardust '80	     3-11
               3.2.2.3  ORFA Process	     3-13
     3.3  REFERENCES	     3-16
4.0  MATERIALS AND MARKETS	     4-1
     4.1  ALUMINUM	     4-1
     4.2  FERROUS METALS	     4-2
     4.3  GLASS	     4-3
     4.4  PAPER	     4-5
     4.5  PLASTICS	     4-8
     4.6  WOOD	     4-10
     4.7  RUBBER	     4-10
     4.8  COMPOST	     4-11
     4.9  REFERENCES	    4-13
5.0  EFFECTS OF RECYCLING ON COMBUSTION	    5-1
     5.1  EFFECTS OF RECYCLING ON THE COMBUSTION PROCESS	    5-1
     5.2  EFFECTS OF RECYCLING ON EMISSIONS  FROM COMBUSTION	    5-4
     5.3  REFERENCES	    5-8

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                                LIST OF TABLES

Table                                                                    Page

 2-i     DISCARDS AND RECOVERY OF MATERIALS IN  THE  MUNICIPAL WASTE
         STREAM,  1984	     2-3

 2-2     SEPARATION AND UTILIZATION OF RECOVERED WASTES IN SWEDEN IN
         1981 AND 1982	     2-6

 3-1     SOURCE SEPARATION METHODS USED TO RECOVER  RECYCLABLES FROM
         MUNICIPAL WASTE	     3-2

 3-2     CENTRALIZED PRESSING TECHNIQUES USED TO  RECOVER RECYCLABLES
         FROM MUNICIPAL WASTE	     3-7
                                      11

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LIST OF FIGURES
Figures
2-1
3-1
3-2

Gross Discards, Materials Recovery, Energy Recovery, and Net
Discards of Municipal Solid Waste, 1960 to 2000 	
Separation Steps in Sorain-Cecchini Process 	
Optional Recovery Processes Available in Stardust
'80 Svstem 	
Page
2-2
3-12
3-14

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                          1. INTRODUCTION AND SUMMARY

     This  report is  an  assessment  of  recycling of  solid waste  as  an
 alternative  or  augmentative waste  management  strategy  to municipal  waste
 combustion.  The information presented in this report was developed as part  of
 a comprehensive, integrated study of municipal waste combustion.  An overview
 of  the  findings of this study  may  be  found in  the  Report to Congress on
 Municipal  Waste Combustion (EPA ">0-SW-87-021a).  Other technical volumes
 issued as  part  of the Municipal kaste Combustion Study include:

     o     Emission Data Base for Municipal Waste Combustors
           (EPA/530-87-SW-021b)
     o     Combustion Control of Organic Emissions (EPA/530-SW-87-021c)
     o     Flue  Gas Cleaning Technology (EPA/530-SW-87-021d)
     o     Cost  of Flue Gas Cleaning Devices (EPA/530-SW-87-021e)
     o     Sampling and Analysis of Municipal Waste Combustors
           (EPA/530-SW-87-021f)
     o     Assessment of Health Risks Associated with Exposure to Municipal
           Waste Combustion Emissions (EPA/530-SW-87-021g)
     o     Characterization of the Municipal Waste Combustion  Industry
           (EPA/530-SW-87-021h)
     As landfill  areas  available for municipal  waste disposal  have  become
 increasingly scarce, renewed  interest has been generated  in volume reduction
 as a part  of waste  management.   A great deal of emphasis  has  been placed on
 combustion as a waste volume reduction  method,  but  there has  also  been  an
 increased  interest  in recycling materials  that would  otherwise end up  in
 landfills.   While  recycling  is  not expected  to eliminate  the  need for
combustion,  it  is being increasingly seen as  a possibility for augmenting  the
volume reduction achieved through combustion.
     Although the United States is  not as active in  the area  of materials recycling
from waste as are some other  countries,  in 1984 about  10  percent  of  material
that would otherwise  have  ended up in disposal  facilities was recovered and
reused.   Most of the  recovery in the United  States  was accomplished through
                                       1-1

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 source  separation,  that  is,  manual  separation by the generator, rather than
 separation  from mixed refuse  in centralized waste  processing  facilities.
 There  are thousands of  source  separation  programs  in operation across the
 United  States  including  400  to  500  curbside  recycling programs.  Some  states,
 particularly  in the Northeast,  have made participation mandatory.   Added to
 the  source  separation programs, there are some  30  to 40 centralized  waste
 processing  plants,  separating materials  from mixed  refuse.   These  plants  are
 producing refuse-derived fuels   and,  in  the  process,  are removing mostly
 non-combustibles from the waste.
     Centralized processing  methods are becoming increasingly  sophisticated
 and  effective at  separating  waste  materials.   A  notable state-of-the-art
 system  developed  in Europe, the Sorain-Cecchini  process, is an  integrated
 recovery  system that  can produce paper pulp, animal  feed, compost,  aluminum
 scrap,  ferrous  scrap,   densified  refuse  derived   fuel,  and  pelletized
 polyethylene  for production  of  sheet  plastic used  in garbage bags.   A simila'r
 process known  as Stardust '80 has been developed and  commercially demonstrated
 in Japan.   Moreover,  plans  are currently  underway  to  construct  integrated
 waste recovery facilities in the United States based  on the  ORFA process.
     Methods  for separation  and uses  for recovered materials  have  been
 established for paper, glass, scrap ferrous  metals,  aluminum, wood waste, yard
 waste,  and  rubber.   Also,  separation methods  and  markets  for recovered
 plastics  are  currently the  subject of rapidly advancing research.   At the
 present time,  technical  and economic factors  combine to make paper  and
 aluminum  the most extensively recycled materials from U.S. waste.
     Recycling, as  a part of an overall waste management  strategy,  should  be a
 positive measure for most localities.   In  general,  recycling of noncombustible
materials would have a  positive effect  on  combustion  operations,  allowing
the potential  for  smaller facilities, more  reliable  operation,  and  decreased
ash handling requirements.
     The  effect of recycling on the  feasibility  of combustion  should be
considered, however,  in  the context  of local refuse characteristics.  For
example, one of the constituents of waste that  is  widely recycled is  paper.
Because paper  contains the largest  portion of the  heating value in the waste,
recycling  goals for paper should be consistent  with  combustor  design heating
                                       1-2

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 value  requirements.   Due  to site-specific  variations  in refuse composition,
 markets  for  recycled materials, combustor design option limitations,  and  other.
 factors, judgements on the optimum combination of recycling and combustion  for
 a  given  waste  management  plan  are  most  appropriately  made  on  a site-specific
 basis.
      In  addition to  augmenting  the  volume  reduction  achievable  through
 combustion  of  municipal  waste,  recycling  may provide  an  opportunity for
 reducing emissions of hazardous materials resulting from combustion or direct
 landfill of  certain  waste materials.   In particular,  recycling  of alkaline
 batteries, which  contain  about 1  percent by weight of mercury, represents  a
 potential means  of  substantially reducing mercury  emissions  from municipal
 waste  combustors.   In Sweden, it  is estimated that  two-thirds  of mercury
 emissions from municipal  waste combustors would be eliminated by recycling
 alkaline batteries.  This  is  significant in  light  of  the fact that emissions
 tests  of state-of-the-art control technologies  applied to municipal waste-
 combustors  have  demonstrated  only  30  to  40 percent  control  of  mercury
 emissions.   (See  "Municipal  Waste Combustion Study:   Emission Data Base  for
 Municipal Waste Combustors;"  EPA/530-SW-87-02/b.)   Furthermore,  to the  extent
 that  combustion  conditions are  improved through removal  of  noncombustible
 materials, pollutants resulting  from the combustion  process  (e.g.  organics,
 carbon monoxide)  should also be reduced through  recycling  of noncombustibles.
     Strategies  for  reducing  emissions  of  other pollutants  from  municipal
 waste  combustion  by removing  materials from the  waste are not  as  easily
 discernible.   For example,  measurements at  one  test facility  showed reduction
 in lead and  cadmium emissions  when metals and glass are removed  from  the waste
 prior to combustion.  Metals  such  as cadmium, lead, and chromium,  however,  are
 contained In paints, colorants, and  stabilizers  are distributed  throughout the
 combustible  portions of the waste.   Therefore,  elimination of their emissions
 through  removal  does not appear  likely.   Further,  the  major sources  of
 chlorine in  the waste, and  hence  the sources of substantial quantities of  HC1
 emissions, are paper and  plastics.   But these materials also have the highest
 heating values of the materials  in the  waste,  so their total  removal  would not
 be practical.  Finally, removal of polyvinyl  chloride (PVC) from the waste has
 been suggested as a strategy  for  reducing emissions of chlorinated dibenzo-p-
dioxins (CDDs)  and chlorinated dibenzofurans  (CDFs).   The mechanisms for
                                       1-3

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 formation  of CDDs and CDFs  in  the combustion of waste  are  not  thoroughly
 understood  at this time.  While research shows that PVC can act as a precursor
 in  CDD/CDF  formation,  it  is  thought that other materials in the waste may also
 participate  in  chemical  reactions leading to CDD/CDF  formation.   Therefore,
 the effectiveness of reducing CDD/CDF through removal of PVC is not clear.
      In  this report  background information on recycling,  its  status  in the
 United States and  abroad,  and  its technical  feasibility are examined.  Also,
 because  recycling  is  expected  to be an  integral  part  of  a solid waste
 management  plan  that  includes  combustion,  potential  effects on combustion of
 removing materials from the  waste  are considered.  This report resulted from a
 brief investigation of a  subject  area in which a lot  of things  are happening.
 Thus, it is  designed to convey  a  sense of  the current status  of  recycling and
 its technical feasibility,  rather than  to embody comprehensive authoritative
 reference material.
     In Section 2, the current extent of recycling in  the United States and  in
 several other countries  is  reviewed.   The material on  the  current recycling
programs and approaches  is  followed by  two sections  on feasibility  of
recycling.    Section  3 contains  information   on  methods for  separation  of
materials and Section 4 contains  information  on uses  and markets for  recovered
materials.    Finally,  Section 5 seeks  to  address  questions  concerning the
effects of recycling activities on combustion processes.
     This  work  was  performed  by  Radian  Corporation  under  EPA  Contract
68-02-4330,  Work  Assignment  9.   EPA's   Work  Assignment  Manager  was
Mr.  David Cleverly of the Strategies and  Air  Standards Division  of the Office
of Air Quality Planning and  Standards.
                                       1-4

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                          2. EXTENT OF CURRENT RECYCLING

 2.1   RECYCLING  IN THE UNITED STATES
      Recycling  in the United States  is  on  the  increasing,  as  shown in Figure
 2-1.*   The  quantities represented  in  the figure are reportedly conservative,
 so  that  further  increases in recycling  and  recovery  activities would  cause an
 increase in the materials  recovery segment  shown.   In 1984 total  material
 recovery amounted to about  10 percent of total discarded material, as shown  in
 Taole  2-1.   This  is compared to  about 25-30% of  municipal  waste  that  has  been
 described  as "easily"  recyclable.    Most of the recovery  to date  has  been
                                        3 4
 accomplished through source separation.  '
       There is  a movement  underway  in  the  U.S.  to  increase  source separation
 of  constituents  in  municipal  refuse.   Recycling programs are being developed
 by  State and Local  governments  throughout  the  United States,  but particularly
 in  the Northeast where  land  for disposal  is  scarce.   The number  of such
 recycling programs  is estimated  in the  thousands.
     There  are 400 to  500 curbside  recycling  programs of  various  sizes
 operating  across the country  with a growing  number,  particularly  in  the
 Northeast,  stipulating mandatory participation.    Typical  participation rates
 for voluntary  curbside collection  programs  in the United  States  are  reported
 to  be  about  33 percent.   Some programs, however, report much  higher  voluntary
 participation  rates.  For example,  a  voluntary curbside recycling  program  in
 San Jose, California reports  70 percent participation, while  another program
                                 g
 in  Kitchener,   Ontario  (Canada)    reports 80  percent   participation.
 Sixty-eight  municipalities  in  Pennsylvania  report  an average participation
                   a
 rate of  54  percent   and, Woodbury Township  in New Jersey reports  recycling
 45 percent of  its waste.    Voluntary residential curbside collection programs
 are estimated  to  reduce  the amount of  waste discarded in  a service  area  by
 about 8  percent.  This estimate  is based on  a  typical  33 percent participation
 rate and assumes recyclables account  for about one  quarter of  most residential
waste.
                                       2-1

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    200-

    180-

    160-

    140

g   120-
o
s   100-
jO


     60-

     40-

     20-
                                   Gross Discards
                                         Material Recoveredi^-Mv1';
                                             ^,.i«,% i'_»-,s'-rxt''-^'^-.*"'^
                                                      •\~_il»ii^i
                                                      Energy
                                            •Net Discards
           1960
1965
                         1970
1975
1980
'<	f"1'
   1985
1990
1995
2000
Finure 2-1. Gross  discards, materials recovery,  energy recovery, and net  discards
            of municipal solid  waste, 1960  to 2000.
                                                  2-2

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     TABLE 2-1.  DISCARDS AND RECOVERY OF MATERIALS IN THE MUNICIPAL WASTE STREAM,  1984
                              (In millions of tons and percent)
                                                                                       1

Materials
Paper and Paperboard
Glass
Metals
Ferrous
Aluminum
Other Nonferrous
Plastics
Rubber and Leather
Textiles
Wood
Other
TOTAL NONFOOD PRODUCT WASTES
Food Wastes
Yard Wastes
Miscellaneous Inorganic Wastes
TOTAL WASTES DISCARDED
Gross
Discards
62.3
13.9

11.3
2.1
0.3
9.7
3.4
2.8
5.1
0.1
111.1
10.8
23.8
2.5
148.1
% of
Discards
42.1
9.4

7.6
1.4
0.2
6.5
2.3
1.9
3.4
0.1
75.0
7.3
16.1
1.7
100.0
Postconsumer
Materials
Recovery
12.9
1.0

0.3
0.6
0.0
0.1
0.1
0.0
0.0
0.0
15.1
0.0
0.0
0.0
15.1
Net
Discards
49.4
12.9

11.0
1.5
0.3
9.6
3.3
2.8
5.1
0.1
96.0
10.8
23.8
2.5
133.0
% of
Discards
37.1
9.7

8.3
1.1
0.2
7.2
2.5
2.1
3.8
0.1
72.2
8.1
17.9
1.9
100.0
Details may not add to totals due to rounding.

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      Mandatory  programs are currently achieving participation of at least  50
 percent  and,  in some cases,  as high as  80 to 90 percent.  The proportion  of
 the  total  waste stream diverted by  these mandatory programs is estimated to  be
 12 to 23 percent.    Container  deposit laws  have  resulted in  80  to  95  percent
 recovery of  returnable  containers,  reducing total  waste in areas where they
                          211
 apply by about 5 percent. '    No  statistics were  found for the amount of
 waste diverted  by central collection centers.
      Materials  being  recovered most successfully in source separation  programs
 include  paper,  aluminum cans,  and glass.
      In  addition  to  curbside  recycling  and  source  separation programs,  there
 are  30 to  40  centralized materials  separation facilities operating in the  U.S.
 These plants  are  recovering materials for reuse  from mixed refuse.  Waste Age
 listed 33  U.S.  separation facilities with total design capacity of 41,000 tons
                                                                    12
 per  day  of waste  operating  in  the U.S.  in its November  1985 update.    While
 the  list  may  not  be  all  inclusive,  previous experience with this, compilation
 indicates  that  it probably contains most of  the  facilities.

 2.2   RECYCLING  IN OTHER COUNTRIES

 2.2.1  Sweden
      In  Sweden  about  40  to  45 percent of domestic waste is  landfilled, about
 45 to 50 percent is  incinerated,  and  about 10  percent  is  separated  and/or
 composted  in  central  processing  plants.   In the period  between  1977  and  1982
 about 15  to  20 centralized processing plants were  built.   In  che  first  two
 years  of  operation problems  occurred  with the new,  undemonstrated technology.
 Even  bigger problems  surfaced  in  the  lack of markets for materials produced in
 the   centralized  processing   facilities.    Meeting the  high   quality
 specifications  placed on  recycled materials  has  been  particularly difficult
 for  recovered materials.  Moreover,  refuse  derived  fuel (RDF) produced by the
 processing plants has not  been successfully burned in  equipment designed and
 built  for  burning other solid fuels.   Compost  produced in  the centralized
 plants has also been difficult to  market because  of  its  glass and  plastic
 content.    Recent  reports  say  that  the  compost  is  currently being used  as
 landfill  cover.  Still, with all  the  problems,  progress is being made as  shown
 in Table  2-2,   and the  Swedish government  is continuing  to encourage and
promote recycling of  municipal waste.
                                      2-4

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     Because of  the  negative  experience with centralized separation plants,
 there has been a growing  interest  in source  separation.  An advantage is seen
 in  the  cleaner  recovered  fractions.   During  1983 recovery of newspapers and
 magazines reached  52  percent.   An  estimated  200,000  tons  were  collected,  out
 of  an estimated  recoverable  portion  of newspapers and magazines in Sweden's
 waste  of  220,000  tons  per  year.   About 90  percent  of the  population
 participates in wastepaper recovery (230 to 240 of 284 municipalities).

     2.2.2  Norway
     About 40 percent of the  waste entering  a  centralized separation plant in
Oslo is reportedly processed  into ferrous, paper, and plastic waste fractions,
which are then recycled.  This  state-of-the-art  facility went  into  full scale
operation in  1985,  processing household waste to  paper,  plastic  chips, and
 ferrous metal for  use in  finished products.    It  also  has  the  capability  to
compost grass, leaves and food waste.
     The recovered  paper  is   fed to  a  small  pulper, then  to  an additional
pulping facility for  marketing  to a  tissue manufacturer.  The  pulp,  treated
with hydrogen peroxide,  would reportedly  be acceptable in Norway  for  food
packaging as well as  for  tissue  and newsprint.   The  paper  recovery  program is
in  accord with  Norway's virgin  fiber  conservation policy which  limits the
                                                          14
amount of forest products available for paper  production.
                   14
     2.2.3  Germany
     Two notable features  of  German  recycling efforts  are  a  paper recycling
policy and numerous  agricultural composting  plants  located in rural  areas.
The government  has a procurement  policy  favoring recycled paper,  and even
school   supplies are  required  to have  a reeded paper  content.   In
Baden-Wurttemburg, compost is used in  vineyards,  gardens,  parks,  and  orchards.
One  environmental   concern  is  the  potential  presence of  heavy  metal
comtamination in the  compost.   Heavy  metals  have reportedly bioaccumulated in
leaves  of grape vines but not in the  grapes  themselves where compost was  used
as fertilizer.  Despite these concerns,  composting is expected to  increase to
90,000  tons per year  in Baden-Wurttemburg.
                                       2-5

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TABLE 2-2.  SEPARATION AND UTILIZATION OF RECOVERED WASTES IN
                   SWEDEN IN 1981 AND 1982
                      (In metric tons)
                       Separated                   Used or sold

                  1981           1982           1981           1982
Iron Scrap
Plastic
Separated Fuel
Compost
4400
2400
37,000
108,000
6800
3900
75,800
121,500
200
0
4400
29,400
1300
30
32,300
56,000
                              2-6

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      In  addition,  landfill ing in  Baden-Wurttemburg has  been  limited to 50
 percent  of total  waste disposal  capacity.  Thus about 50  percent  of MSW is
 managed  by  combinations  of  refuse  recycling  and  refuse  combustion.
 Currently  in Bavaria landfills account for only 30 percent of waste disposal
 capacity,  and,  therefore, recycling  and  combustion  are  the major means of
 waste disposal.
      Another feature noted in Germany's waste management included collection
 bins  located at combustor sites  „, Wurzburg and Stuttgart  for  separation  of
 hazardous  items  (batteries,  aerosols,  explosives)  from waste before  they enter
 the combustor.   By removing  tnese  items plant operators hope to avoid  damage
 to equipment and  to  minimize emissions  of metals.

      2.2.4  Denmark14

      In  Copenhagen  labelled  containers  are  available  for  disposal   of
 segregated waste,  e.g., yard  waste,  furniture,  aerosol  cans,  etc.  Also  in
 Denmark,  aluminum cans are  not  used  for beverages,  and beverage  containers
 must  be  commercially reusable.   Containers  were  reported to be  used  an  average
 of 30  times  compared to average  usage of less than 10 times in U.S.  markets.
 The return rate was  estimated to be 99.6  percent.
      Government procurement  efforts have  helped to create  a strong market for
 recycled  paper.   Danish  cardboard is  more than  90  percent  recycled  and
 photocopy  paper contains  45  percent recycled paper and  straw.  All  available
 recovered  ferrous scrap  is  recovered  by the Danish  steel  industry,  and
 discarded  tires are  being considered  for use in highway asphalt.  Also under
 investigation is  the use  of  food waste from restaurants and  institutions  for
 processing into pet  food.  A plastics reprocessing plant is scheduled  to  open
 soon with  a  capacity of 25,000 tons per year for  processing  source  separated
 plastic.

     2.2.5   Italy
     The city of  Rome has several  materials  separation  and recycling  plants
based  on the  Sorain-Cecchini process.  These plants recycle  about 65 percent
of the waste  (about  500,000 tons/year) they  receive  from Rome.   '     Paper,
p.lastic,  ferrous metal, and  compost are recycled.
                                       2-7

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      2.2.6   Japan
      In  1983,  about 67 percent of municipal solid waste collected in Japan  was
 incinerated  and the  remainder was  landfilled.   The shortage  of available
 landfill  space has encouraged the practice of  combustion  which  is  expected
 to  continue  to increase.   Also,  strong emphasis has been  placed  on  recycling
 and re;  ,rce recovery (i.e.,  in  the form of materials and/or energy) due  to
 Japan's  dependency on imported resources.     These objectives are  being met
 through  a combination of  source  separation programs and centralized processing
 facilities.16'17
      Virtually all components  of municipal  solid waste  are subject  to
 recycling  and/or  resource  recovery  including:   paper, glass,  ferrous  and
 nonferrous   (i.e.,  aluminum)   containers,  plastic,  and  used electrical
 appliances.   In 1984, Japan recycled  more than 50 percent of the  discarded
                                                             18
 newspaper as well  as  81  percent of the  discarded  cardboard.     The Japanese
 government  maintains  a buffer  stock of wastepaper to help  stabilize  the
       19
 market.     By 1988,  about  60  percent  of returnable and nonreturnable  glass
 beverage containers  is  expected to be manufactured from  used glass Gullet.
 Supply of glass cullet is  enhanced by  an approximate return  rate of 95  percent
 of  returnable  beverage  containers.   Since 1977, Japan  has  operated a  center
 where discarded electric   appliances  (e.g.,  televisions,  refrigerators, and
 washing  machines,  etc.)   are processed  and   separated  into  reusable
 components.     In general, Japan  relies  on  non-profit  organizations  and
 volunteer groups  to  promote  public  awareness  and to  encourage  public
 participation  in recycling programs.
     Centralized  processing facilities  play  an important  role  in Japan's
 recycling and  resource  recovery  objectives.  Commercial  processes  have been
 implemented  to  sort mechanicall/ and  manually  valuable recyclables  from mixed
 refuse prior to  combustion.     Recently, Japanese innovations  have  been
demonstrated in pilot plants  that  produce methane gas from  refuse  by a high-
 rate methane fermentation process.   In  addition,  usable  fuel oil  has  been
                                                                      21
produced from paper and plastics by a  pyrolysis oil  recovery process.     These
processes enhance  resource recovery,  are economical, and provide alternatives
to the predominant waste  disposal  techniques:    landfill  and  combustion.   The
Japanese government  promotes these   technological  developments   through
financial and tax  incentives.
                                       2-8

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2.3  REFERENCES


 1.  Franklin Associates, Ltd.  Characterization  of  Municipal  Solid Waste in
     the United States, 1960 to 2000.   Final  Report.   EPA  Contract 68-01-7037,
     Work Assignment 349.  July 1986.

 ">.  Clapham, W.B.  An Analysis of the Potential  Effect  of Beverage Container
     Deposit Legislation on Municipal  Recycling Programs.   Journal of
     Environmental Systems, Volume 14, 1984-1985.

 3.  Cutter, Susan.  Resource Recovery, An Overview  in Environmental  Policy:
     Solid Wastes.  Volume IV.  Ballinger Publishing Company,  Cambridge,
     Massachusetts.  1985.

 4.  Resource Recovery Facts and Figures.  Resource  Recovery Update.   Volume
     9, No. 5.  May 1980, p. 2.  National Center for Resource Recovery,  Inc.
     Washington, D.C.

 5.  Bronstein, Scott.  Where, Oh, Where to Empty the Trash in The New York
     Times.  September 14, 1986, p. 6F.

 6.  Hertzberg, Richard.  New Directions in Solid Waste and Recycling.
     BioCycle, Volume 27, January 1986.  pp. 22-26.

 7.  Pettit, C.L.  Trends  in Collecting Recyclables.  Waste Age, Volume 17,
     June 1986.

 8.  Copeland, Vivian S. Recycling Success in  Canada.  80% Participation!
     Waste Age.  November  1984.  pp.  38-42.

 9.  Curbside Recycling in Pennsylvania -- 1985.  Pennsylvania Department of
     Environmental Resources.  Bureau  of Waste Management.

10.  Hang, Walter Liong-Ting and Steven Romalewski.   The  Burning Question:
     Garbage Combustion Versus Total  Recycling in New York City.  The New
     York Public Interest Research Center, Inc.  1986.

11.  Steisel, Norman, Paul D. Casowitz, and Joan Edwards.  A  Status Report on
     Materials Recycling Activities in New York  City.  The City of New York
     Department of Sanitation.  December 1985.

12.  Update:  Resource Recovery Activities Report.  Waste Age.  16 (11):
     99-183.  November 1985.

13.  Rylander, H. Waste Management in  Sweden.  A National Report.  Waste
     Management and Research (3) 81-88.  1985.

14.  Hinchey, Maurice, Chairman.  New  York State Legislative  Commission  on
     Solid Waste Management in Norway, Sweden, Denmark, and  Germany:   Lessons
     for New York.  December 1985.  Albany, N.Y.


                                       2-9

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15.  Institute for Local Self-Re!iance (1985).  A Practical Alternative Solid
     Waste Management Program for the City of Philadelphia.  Submitted to the
     Rules Committee, Philadelphia City Council.  January 8, 1985.  p. 98 as
     cited in Hang, Walter Liong-Ting and Steven Romalewski.  The Burning
     Question:  Garbage Combustion Versus Total  Recycling in New York City.
     The New York Public Interest Research Center, Inc.  1986.

16.  Recycling '86:  Turning Waste into Resources.  Published by the Clean
     Japan Center.  1986.

17.  Irisawa, Shizuko.  Aiming at Creation of a Beautiful Town and Resource
     Reutilization.  Clean Japan, No. 7, 1985.

18.  Resource Recycling Journal.  Volume VI Number 4.  September/October 1985.
     p. 8 as cited in Hang, Walter Liong-Ting and Steven Romalewski.  The
     Burning Question:  Garbage Combustion Versus Total Recycling in New
     York City.  The New York Public Interest Research Center, Inc.   1986.

19.  Hinchey, Maurice 0., chair.  The Economics of Recycling Municipal Waste.
     A Staff Report to New York State Legislative Commission on  Solid Waste
     Management.  Albany, New York.   1986.

20.  Ida, Nobuo.   Example of Development and  Operation of Municipal  Refuse
     Recycling System.  Clean Japan, No. 7, 1985.

21.  Stardust '80:  Putting Refuse to Work.   Agency  of Industrial Science and
     Technology MITI (Japan).  No date.
                                      2-10

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                             3.  SEPARATION METHODS

      Two primary  methods  are used to separate recyclable materials from MSW:
 source separation and  centralized processing.  Source separation is
 accomplished  when the  waste  generator  (e.g., residential consumer, retail
 store, office building)  sets aside  recyclable wastes from other waste
 materials.   Centralized  processing  separates recyclable waste from mixed
 municipal  waste after  it  has been collected for disposal.  This section
 describes  how waste  materials are recovered by these two methods and describes
 a  few current programs in the United States and other countries that have
 successfully  implemented  recycling  using these separation methods.

 3.1   SOURCE  SEPARATION
      Materials most  commonly recovered  through source separation  are used
 newspaper, glass,  and  aluminum cans from residential waste, used  corrugated
 boxes from commercial  waste,  and high-grade office  paper from office
 buildings.   Source separation of other  municipal waste  components  such  as
 plastics, rubber,  and  organic materials is currently performed  on  a much
 smaller  scale.  Source separation methods  in use for recovering recyclables
 from  municipal  waste (Table  3-1) are described in the following section.

 3.1.1  Source  Separation  Methods
      Source separation of residential waste components  is primarily achieved
 through  programs  relying  on  curbside collection, neighborhood collection
 centers, or a  combination of the two.   Additional source separation of  glass,
 aluminum, and  in  some  cases,  plastic containers  is  achieved as  a  result of
 container deposit  laws.
     An  estimated  400-500 curbside  recycling programs of varying  sizes  are
operating in  the  United States.   Two  successful programs are operating in  San
Jose, California  and in Kitchener,  Ontario  (Canada). Both of these programs
 attribute their success in part to  making  attractive containers available  in
which residents can store recyclables  and  which  are placed  at the curb on
             2 3
pick-up days.  '    Neighborhood collection  centers,  while requiring less
equipment, personnel and  maintenance than  curbside  collection programs,
generally achieve  lower participation  and  lower  volumes of  materials.

                                       3-1

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                TABLE 3-1.   SOURCE SEPARATION METHODS USED TO RECOVER RECYCLABLFS FROM MUNICIPAL WASTE
                      Residential Waste
         Source Separation
              Methods
   Materials.
   Recovered'
                                  Commercial  Waste
Source Separation
     Technique
     Materials
     Recovered
CO
i
IVJ
        Curbslde collection
        Voluntary drop-off centers
        Profit buy-back centers
        Private/civic organization
         fund-raising drives

        Container deposit  laws
Newspaper, glass*
 aluminum cans
Newspaper, glass,
 aluminum cans

Glass, metal cans,
 newspaper* magazines,
 corrugated boxes,
 plastics and wood

Newspaper
Aluminum, glass, and
 plastic containers
Collection by waste
 dealers
Employee recycling
 program
Corrugated boxes,
 11quor and wine
 bottles

High-grade office
 waste, newspaper
        Home composting programs     Organlcs
         ^Programs vary  1n types of materials recovered.  Materials listed are typical,

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      Container deposit  laws encourage consumers to separate and return  used
 glass,  aluminum,  and plastic beverage containers by placing a returnable
 deposit on  them.   Such  laws are currently in effect in Oregon,  Maine,
 Massachusetts, Vermont, Delaware, Connecticut, New York, Michigan,  and
 Iowa.5'6
      Source separation  of used corrugated boxes occurs primarily at retail
 stores,  supermarkets, factories, and department stores.  Waste paper dealers
 and  recycling mills purchase waste from large generators of used corrugated
 boxes and arrange  for its removal.  The businesses generating corrugated waste
 typically operate  compacting and baling equipment to reduce the volume of the
 waste for economical storage and transport.  Recycling  is also practiced by
 smaller  ;usinesses generating relatively small amounts  of used corrugated
 boxes.   Private  individuals collect waste corrugated cardboard free of charge
 from these  businesses and then sell it to waste paper  dealers.  About 40
 percent of  used  corrugated cardboard is recycled  in this manner in  the United
 States.6
      Paper  recycling programs in offices are  becoming  increasingly  common as  a
 form of source separation, since an estimated  90  percent of  office  waste is
 waste paper.  Office paper also  is usually  high grade.  A  recant survey of 12
 unidentified office paper recycling programs  sponsored by  EPA  indicated an
 average reduction  in office waste of 34 percent,  and,  in one case,  of  78
 percent.    Offices with waste paper recycling  programs request employees to
 separate recyclable waste paper  in desk top or centrally located bins.  The
 collected high-grade paper is then sold to  a  waste  paper dealer who performs
 additional  sorting and  removal of contaminants, as  necessary,  and  arranges for
 sale  and transport of the waste  paper to a  recycling  mill.
     Current source separation practices also  recover  small  quantities  of
 plastics, rubber,  and organics from municipal  waste.   Plastic  soft drink
containers  are the only plastic waste currently recycled  in  significant
quantities  in the United States.  The major mechanism for  collecting these
plastic  containers is beverage container deposit  legislation which requires
consumers to pay a returnable deposit on all  disposable beverage containers.
Retailers collect the used containers and  sell  them to used  plastic bottle
processors,  where the used containers are  sorted,  cleaned,  and processed  to
remove contaminants (e.g., metal caps, labels)  by a variety  of manual  and

                                      3-3

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 mechanical  processes.   Used plastic is currently used to make fiberfill  and a
 variety of  extruded  products.   Some recycling centers provide facilities  for
 individuals to  dispose  of  tires.   Some communities encourage recycling  of
 organic waste through composting.  The communities operate facilities  which
 accept  and  process organic waste into commercial compost to be used  in
 landscaping and gardening.  In addition, some communities have established
 programs providing materials and instructions for residents to perform their
                2
 own  composting.

 3.1.2   Source Separation Programs at Some Localities
     Successful recycling  programs involving source separation of residential
 and  commercial  waste have  been implemented in numerous communities across the
 United  States.  Some of the most aggressive source separation programs have
 been implemented or  are currently being implemented in large cities where
 development of  alternatives to landfilling of municipal wastes bas become a_
 major issue.  Examples  of  source separation programs  in these cities  are
 described below.
     In  New York City,  the Department of Sanitation nas recently  implemented
 five pilot  programs  with the objective  of  increasing  the  level of source
 reparation  of residential  wastes (i.e., newspaper, glass,  and metal
 containers).  These  programs include:  (1)  a newspaper recycling program for
 high-rise apartment  buildings;  (2) establishment  of  "buy-back" centers  in
 lower income neighborhoods that  purchase glass,  aluminum,  bi-metal  cans,  tin
 cans, newspaper, magazines, corrugated  paper,  plastics,  and wood  from local
 residents;  (3)  curbside collection of  newspaper,  glass,  and metal cans, in
 low-density neighborhoods;  (4) establishment  of a network of voluntary
 drop-off centers in  Manhattan; and  (5)  containerized  recycling  program for
 materials other than newspapers  in apartment  buildings.   Collectively,  the
 City of  New York estimates these residential  source  separation  programs could
 result  in a 5 percent reduction  in the  total  municipal wastes generated, or
 about 1300  tons/day.  The  New York State Returnable  Container Law could
 potentially recover  an  additional 5 percent  of the residential  waste in the
                                                          Q
 form of glass,  aluminum, and plastic beverage containers.
     The City of New York  has also  implemented programs to promote recycling
of office waste paper.  The City funds  a private organization which  provides

                                       3-4

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 technical  assistance  to  offices  interested in setting up office paper
 recycling  programs.   Further,  the City recently expanded their city agency
 office  waste  paper  recycling  program with a resulting increase in tonnage of
 paper recycled.   The  City  also sponsors waste paper recycling programs for
 non-profit organizations and  a program with scrap paper dealers to promote
 desk-top recycling  by their clients.
      In San Francisco, used newspaper is collected for recycling by community
 groups  as  fund-raising drives, by community nonprofit recycling centers,
 by  for-profit  buy-back recycling centers, and by garbage collectors.  In
 addition,  an  apartment newspaper recycling program has recently been
 implemented.   Other recyclables, including glass and aluminum cans, are also
 collected  by  voluntary drop-off and buy-back recycling centers.  Residential
 curbside collection of recyclable materials was discontinued in San Francisco
 because of illegal  scavenging  and because it could never service more than
 about one-third of  the population, due to San Francisco's unique demographics
 and topography.
      In addition  to source separation programs for residential wastes,  the
 City of San Francisco has  implemented several programs to increase  recycling
 of commercial  wastes.  The City collects wine and liquo~ bottles from bars  and
 restaurants,  separates corrugated boxes  from mixed waste at  the City's
 transfer station, and sponsors an office paper recycling program.   This office
 program provides  technical assistance and promotional materials  to  offices
 interested in  establishing a  paper recycling program.   In addition,  all  city
 offices currently operate  a waste paper  recycling program.   Recycling  of waste
 wood and metals is  performed  at  the City transfer station,  and a  composting
 program recycles  animal  waste  at the City Zoo.    Altogether,  the  City
 estimates  mat about  22  percent  of the  residential  and  commercial  waste
 generated  by  the  community is  recycled.

 3.2  CENTRALIZED  PROCESSING
     Virtually all of the  post-consumer  newspaper,  glass,  and aluminum
 recycled in the United States  is recovered  by the source separation methods
described  in Section  3.1.  Yet only one-third or  less  of the total  quantities
of these discarded waste items are currently recycled  by source separation
methods.    Another method for recovering additional  recyclables in municipal

                                      3-5

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waste is by centralized processing of the mixed waste stream.   Centralized
processing to remove recyclables is practiced to a small  degree at  municipal
waste transfer stations.  It is also a key operation performed in  conjunction
with many waste-to-energy facilities, particularly those  producing  and  firing
RDF.  Centralized processing techniques used to recover recyclable  wastes  from
mixed waste (Table 3-2) are described in the following section.

3.2.1  Description of Centralized Processing Techniques
     Transfer stations are operated by some communities to reduce
transportation costs when convenient landfills are unavailable.  To further
reduce waste hauling costs, many transfer station operators selectively remove
recyclables from the dumped waste.  In particular, large metal appliances,
white goods, auto parts, etc., are removed to prevent damage to compacting
equipment.  Used corrugated cardboard, newspaper, and wood may also be
recovered from the mixed waste.  These sorting operations generally are
                                           8 12
performed manually at the transfer station.  '
     Another example of centralized processing to remove recyclables from
municipal waste is selective sorting of commercial office building waste.
Instead of being combined with residential waste, commercial office building
waste is routed to a processing plant whe>d  nonpaper waste  is  manually
removed.  This technique is practiced in at  least one city  (San Francisco).
     Resource recovery facilities recover the materials  and energy value of
municipal waste, thereby reducing the volume that has to be disposed in
landfills by about 60 to 90 percent.  Some of these  facilities separate metals
and other noncombustibles from the waste, and combust the  remainder for  fuel.
Others process the mixed waste to maximize recovery  of all  recyclables
including paper and plastics.
     Two methods of separation are employed  to  remove  recyclable waste
fractions:  front-end separation  and  back-end  separation.   Front-end
separation removes recyclables before waste  combustion.   Back-end  separation
removes recyclables from the combustion  ash  or  from mixed  fractions  recovered
by front-end processing.  Front and  back-end separation  techniques used to
recover recyclable materials are  described  below.   Some  commercial processes
using these techniques are described  in  Section 3.2.2.
                                       3-6

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                TABLE 3-2.  CENTRALIZED PROCESSING TECHNIQUES USED TO RECOVER

                              RECYCLABLES FROM MUNICIPAL WASTE
  Waste Type
Ferrous metals
                                              Centralized Processing Techniques
Front-end separation
(before Incineration)
Magnetic separation
Back-end separation
(after Incineration)
 Magnetic separation
Nonferrous metals
  (e.g., aluminum)
Glass
Paper
Plastics
Jigging
Water elutrlatlon
Heavy media separation
Eddy-current separation
Electrostatic separation

J1 gg 1 ng/ sc r een 1 ng
Froth flotation
Optical sorting
Electrostatic separation

Manual sorting
A1r classification
Electrostatic separation

A1r classification
Electrostatic separation
 Jigging
 Electromagnetic separation
 J 1gg1ng/screen1ng
 Froth flotation
                                                                 None
                                                                 None

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      3.2.1.1   Separation  Techniques  for_Ferrous Metals.
      Magnetic seoaration--Ferrous  metals  are effectively removed from raw
 refuse and combustor residue  by  magnetic  separation.   In front-end
 separation processes,  paper and  other  sheet materials  entrained with the
 ferrous fraction  can be reduced  with a multi-stage separator.  The recovered
 ferrous fraction  may be air classified to  separate "tin" cans from heavy
 miscellaneous steel  scrap.  The  tin  cans  must undergo  a commercial detinning
 process before being recycled as scrap.
      Magnetic separation  is also used  to  recover ferrous materials in
 combustor  residue.   In contrast  to ferrous scrap recovered by front-end
 processes,  ferrous  recovered  from  back-end processes is cleaner having gone
                                14
 through the combustion process.
      3.2.1.2   Separation  Techniques  for Nonferrous Metals.
      Jigging.--Jigging  is  a  wet process that separates  materials of different
 specific gravities  by  pulsating  water  with a jig.  Heavy particles settle on'
 the  screen  and light particles are skimmed from the  top.  Jigging has been
 demonstrated  to separate  aluminum  effectively from heavy nonferrous  metals
 (zinc,  lead,  and  tin)  in  raw  refuse  and to separate  a  glass  and aluminum
 fraction from heavy  nonferrous metals  in  combustor residue.
      Water  e!utriation--In  the water elutriation technique,  a controlled
 rising  current of water is  employed  to create an effective,  controllable
 specific gravity.   Light  material  floats  to the surface and  overflows while
 heavy materials sink.  This process  has been used to process the  air
 classified, heavy portion of  raw refuse,  separating  wood,  textiles,  rubber,
 leather, and  plastics  from  glass,  aluminum, and other  nonferrous  metals.   This
 process has also  been  used  to recover  a high-grade metal concentrate from
 scrap automobile  shredder rejects  (i.e.,  the nonmagnetic fraction from
 shredding junk autos).
      Heavy media  separation—Heavy media  separation  utilizing  fluids with
 specific gravities greater  than  1  have been demonstrated to  separate aluminum
 from  heavy nonferrous  metals  in  raw  refuse and combustor residue.
Commercial  recovery  of aluminum  has  been  achieved with heavy media  separation
using suspensions of ferrosilicon, magnetite, or galena.
      Eddv-current separation--Eddv-current separation  is a dry  separation
process based  on the principle that  an electromagnetic field passed through
nonferrous  metals induces eddy currents in the metals  which  interact (or
                                       3-8

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 counteract)  with  the magnetic  field.  These interactions exert a repelling
 force on  the metals, separating them from the fields.  Devices based on
 eddy-current separation  have been demonstrated to recover a nonferrous metal
 fraction  from raw refuse.
      Electrostatic  separation--Electrostatic separation devices use an
 electrically grounded  rotating drum and one or more electrodes.  As feed
 materials  enter the electrostatic field generated by the electrodes, the
 individual  particles are charged.  Conductors, including metal and paper,
 immediately  lose  their charge  and are repelled by the grounded drum.
 Nonconductors, including glass, plastics, rubber, bone, wood, textiles and
 ceramics behave as  nonconductors and remain pinned to the drum.  This process
 has been demonstrated  to recover aluminum and other nonferrous metals from
 municipal  refuse.
      3.2.1.3   Separation Techniques for Glass.
      J i qq i nq/screeni nq--J i qq i nq separates glass and aluminum from nonferrous'
 fractions  in  raw  refuse and combustor residue.  Glass is subsequently
 separated  from aluminum by passing the mixture through  a roll crusher which
 pulverizes the glass and flattens the aluminum, followed by  screening to
 separate the  two  materials.
      Froth flotation — Froth flotation is a technique using differences  in the
 chemical properties of finely  ground glass and contaminants  to  achieve
 material separation.   The glass and contaminants  are mixed with  a
 physicochemical reagent, which adsorb preferentially to the  glass  surface
 glass.  The  coated  glass attaches to bubbles  formed  by  agitating the  mixture
 with  air and  is swept  off the  top.  This process  is  generally  performed in  a
 series of  froth flotation cells.16
      Optical  sorting—Optical  sorting is a process designed  to remove foreign
materials  from glass fractions and to separate glass by color.   The process
 employs a  series  of photocells which separate the opaque particles from the
 transparent  particles  by matching the intensity of light transmitted through
 the particles  with  a fixed-shade background.
     3.2.1.4   Separation Techniques for  Paper.
     Manual sorting—Prior to  shredding  municipal  waste for  resource recovery
processing, large items that could potentially damage  the  shredding equipment
are removed.    In  conjunction with this step,  sorting personnel  may also be
                                      3-9

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 instructed to remove newspaper and corrugated boxes from the raw  refuse.
 These materials are relatively easy to remove and may be sold directly  to
 waste paper dealers.
     Mr classification—After shredding, the first step in most  materials
 recovery processes  is to air classify the mixed waste into a lighter, mainly
 organic fraction and a heavier, mainly inorganic fraction.  The light  fraction
 consists primarily  of paper and plastic.   The heavy fraction may  be further
 air classified to remove any remaining paper.
     Electrostatic  separation--Electrostatic separation, as described
 previously, has been demonstrated to separate paper and plastic from air
 classification streams.

 3.2.2  Description  of Commercial CentralizedProcessing Systems
                                    17 18
     3.2.2.1  Sorain-Cecchini System  '  --The Sorain-Cecchini system,
 developed about 20 years ago, automatically processes municipal waste into  ~
 recyclable fractions (Figure 3-1).  The system further upgrades these
 materials into marketable products, including aluminum and ferrous scrap,
 baled cardboard, polyethylene pellets, paper pulp, soil conditioner (i.e.,
 compost) and ecological fuel.  Fourteen plants using the Sorain-Cecchini
 process are under construction or operating presently worldwide.  Locations
 include Italy, Brazil, Japan, Canada, Equador, Norway, Yugoslavia and
 Czechoslovakia.  In addition, feasibility studies  have been  performed for
 construction of additional facilities using the  Sorain-Cecchini process  in the
 United States, England, Holland, Venezuela, Soviet Union,  and  numerous  other
 countries.   The Sorain-Cecchini system processes waste  through a  series  of dry
 primary and secondary separating operations to segregate  the following
 fractions:   ferrous metals, aluminum, film plastic,  organics,  and densified
 refuse derived fuel (DRDF).  The recovered organics  fraction consists  of hard
plastics,  organics, glass, ceramics,  sand, and ashes.   This  system can  also
recover paper as cardboard and pulp.  Also,  the  recovered organics  fraction
can be processed as animal feed, high grade  compost,  and  low grade compost.
     The incoming waste is sorted  to  remove  over-sized  pieces and waste that
cannot be processed.  The remaining waste  is  passed  through a leveling device
 and a primary screen which separates  the large  fraction (nominal  8 in.),
                                       3-10

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 consisting mainly of paper, wood, and film plastic from the small,  heavier
 fraction, consisting mainly of organics, glass, ceramics,  metal,  sand,  and
 ashes.
      Both the large and small fractions from the primary screen undergo a
 series of classification steps, each producing a light and heavy  fraction.
 These fractions are further processed into like fractions  and distributed to
 recover  lines where materials are processed into a marketable form.
      Ferrous metals are recovered by magnetic separation at three points in
 the waste recovery process.  The recovered ferrous fractions are  fed to a
 specially designed hammermill which cleans the ferrous fraction through
 friction and densifies it through compression.  A final magnetic  separator
 separates the ferrous metals from the nonmetals loosened by the hammermill.
 Following ferrous recovery, the heavy fractions are processed by eddy current
 separation to recover aluminum.  The aluminum fraction is crushed to densify
 the material and to reduce voids.
     Paper is separated by a series of  air classification steps from plastic
 and other heavier materials and is either processed into DRDF or paper  pulp.
After densification, the DRDF is sold or used as  fuel  on-site.  The recovered
 plastics fraction is shredded, washed,  dried, and processed  into pellets.
     Organic fractions, consisting of small organics,  glass, ceramics,  sand,
 ashes, hard plastic, small pieces of wood, and  some of the  smaller heavier
 materials which are otherwise being recovered,  are separated at  several  points
 in the waste recovery process.  These fractions  are processed  into a raw
 compost in an aerobic digester and then cleaned  to remove  inorganic materials.
 The remaining organics fraction may be  further  processed  to make  animal feed
 or commercial compost.

                          19
     3.2.2.2  Stardust '80    Stardust  '80  is  a comprehensive, multi-purpose
resource recovery system developed by the Japanese government.   The  system
features processes for sorting mixed waste  into components  from  which  compost,
pulp, fuel  gas and oil, and light-weight  aggregate may be recovered.   The
system is currently in operation in Tokyo and  Yokohama.
                                       3-11

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 i
rv>
                            Small
                           Fraction
                             i
                          Magnetic
                         Separation
I
                         Screening
                             I
                             Air
                        Classification
                                                          Mixed
                                                          Waste
                                                       Removal of
                                                    Oversized Objects
                                                       . Large
                                                        Fraction
                                                           Air
                                                      Classification
                                            Differential
                                             Shredder/
                                           Rotary Screen
                            Figure 3-1.   Separation Steps in Sorain - Cecchini Process

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     At the Yokohama plant, incoming refuse is separated by a semi-wet
 pulverizing classifier into three primary fractions:   garbage,  paper,  and
 plastics.  Before 1981, the garbage fraction underwent further processing  to
 separate glass and dirt, before being converted to refined compost by  a high
 rate composting system.  The glass and dirt removed was subsequently processed
 into light-weight aggregate.  The paper fraction was air   assified and then
 further processed to recover refined pulp.  The plastics fraction was  passed
 through a magnetic separator to recover ferrous metal, shredded and then
 processed into fuel gas (heating value - 620 Btu/scf) by a two-bed pyrolizer.
 In 1981, a high rate fermentation system was added to convert the garbage
 fraction into methane with a heating value of 650 Btu/scf.
     At the Tokyo plant, only the paper and plastics fractions separated from
 incoming refuse are further processed on-site.  The paper-plastics fraction
 recovered at the Tokyo plant is processed through a fluidized bed pyrolysis
 oil recovery system into fuel oil having a heating value of  14,400 Btu/lb and
 a solid fuel with a heating value of 6,660 Btu/lb.
     Developers of the system emphasize that different combinations of  the
 recovery processes demonstrated at the Yokohama and Tokyo  plants may be used
 at other locations depending on site-specific needs.  For  example, the
 composting process is recommended for facilities  in cities with  large
 populations where refuse typically has a higher proportion of garbage.
 Garbage is more difficult to incinerate than other refuse  types.   Likewise,
 methane fermentation systems are recommended when municipal  waste  and  sewage
 treatment efforts can be combined.  A flow diagram  (Figure 2)  illustrates the
 basic recovery process operations offered by the  Stardust  '80  system.

     3.2.2.3  ORFA Process    A recent development  in  centralized waste
 processing is the ORFA process.  A prototype  facility  utilizing  this  process
 has been operating in Switzerland for the past  3  years.   Plans  are currently
 underway to construct commercial facilities based on  the ORFA process in the
 United States.  The ORFA process converts municipal  refuse into  three
marketable fractions.  The first fraction,  ORFA fiber,  is a  sanitized and
 stabilized fibrous material composed mainly of  cellulose.   Its expected uses
 include feedstock for agricultural products and pulp and paper,  and in energy
                                       3-13

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Lightweight
Aggregates
Glass and Dirt
 Separation
           High-rate
          Composting
           High-rate
         Fermentation
                                                         Mixed
                                                         Waste
                                                          ±
                                                      Classification
Refined Pulp
 Recovery
                          C Methane  j








T
I
1
1
1
f
Pyrolysls OH
Recovery
T
l
L >.







Magnetic
Separation


Pyrolysls Gas
Recovery
                                                                  Optional Process
                                                                    •  Routes
                     Figure 3 - 2.   Optional Recovery Processes Available In Stardust 80 System

-------
and building materials industries.  The second fraction, Granulite, is a
composite of plastics, glass, nonferrous metals, sand, dust, grit, and other
heavy materials, and is intended for use in building materials and road repair
applications.  The third fraction, a ferrous metal fraction, is shredded for
sale to scrap metal dealers.  The primary recovery steps in the ORFA process
include size reduction and ferrous metal removal followed by drying,
stabilization, and sanitization by ozone.  The remaining processed waste is
then separated into ORFA fiber and Granulite by a series of size  and density
classification steps.  To reduce odorous emissions from the various process
steps,  exhaust gases are vented to a bio-filter which traps odorants  and
neutralizes them by aerobic digestion.
                                      3-15

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3.3  REFERENCES

  1.  Hertzberg, Richard.  New Directions in Solid  Waste and  Recycling.
     BioCycle, Vol. 27, January 1966.  pp.  22-27.

  2.  Copeland, Vivian S.  Recycling Success in Canada:   80%  Participation!
     Waste Age, Vol. 15, November 1984.  pp.  38-42.

  3.  Salimando, Joe.  Empire:  Pioneers in  Recycling.   Waste Age,  Vol.  17,
     January 1986.

  4.  Pettit, C. L.  Trends in Collecting Recyclables.   Waste Age,  Vol.  17,
     June 1986.

  5.  Bronstein, Scott.  Where, Oh, Where to Empty  the Trash?  The New York
     Times.   September 14, 1986.  p. 6F.

  6.  Plastics Recycling:  A Revival.  Chemical Engineering,  June 25,  1984.
     pp. 22-26.

  7.  How To Recycle Waste Paper.  Published by the American Paper Institute,
     Paper Recycling Committee, 1985.

  8.  Transfer Center Serves Oregon Communities.  Waste Age,  Vol. 14,
     December 1983.  pp. 27-30.

  9.  Steisel, Norman, Paul D. Casowitz, and Joan Edwards.  A Status Report on
     Materials Recycling Activities  in New York City.  The City of New York
     Department of Sanitation.  December 1985.

10.  Cotter, Daniel A.  San Francisco's Integrated Recycling Program.
     Proceedings of the Twelfth Biennial Conference, 1986 Waste Processing
     Conference.  ASME.  Denver, Colorado.  June 1-4,  1986.

11.  Franklin Associates, Ltd.  Characterization of Municipal Solid Waste in
     the United States, 1960 to 2000.  Final  Report.   EPA Contract 68-01-7037,
     Work Assignment 349.  July 1986.

12.  Transfer Station Designed for Maximum Recycling.  World Wastes, Vol. 26,
     April  1983.

13.  Bernheisel, J. F.  Materials Recovery Systems.  Resource Recovery and
     Utilization, ASTM STP 592, American Society for Testing and Materials,
     1975,  pp.  64-70.

14.  Mahoney, Patrick F.  There's Gold  in That There Ash!   Waste Age,  Vol.  17,
     April  1986.
                                      3-16

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15.  Makar, H. V. and R. S. DeCesare.  Unit Operations for Nonferrous Metals
     Recovery.  Resource Recovery and Utilization, ASTM STP 592, American
     Society for Testing and Materials, 1975, pp. 71-88.

16.  Archer, Tom and Jon Juls.  RCRA Study of Glass and Plastic Resource
     Recovery.  Proceedings of the Seventh Annual Research Symposium,
     EPA600/9-81-002C.  March 1981.

17.  Cashin, Francis J. and Pretio Carrera.  The Sorain Cecchini System for
     Material Resource Recovery.  Proceedings of the Twelfth Biennial
     Conference, 1986 Waste Proc^sing Conference.  ASME.  Denver, Coloraoo.
     June 1-4, 1986.


18.  KLES Incorporated.  Energy and Materials from MSW - Sorain Cecchini.  No
     date.

19.  Stardust '80:   Putting Refuse to Work.  Agency of Industrial Science and
     Technology MITI (Japan).  No date.

20.  Introduction to the ORFA Process and ORFA Corporation of America.  ORFA
     Corporation of America.  September 1986.
                                       3-17

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                        4.  MATERIALS AND MARKETS
      This  section presents  information on the separation feasibility and
 marketability  of  individual municipal waste constituents.  The municipal waste
 components  covered  in this  section include: aluminum, ferrous metals, glass,
 paper,  plastics,  wood, rubber and organics.  Techniques currently used or
 under development to separate each of these components from municipal waste
 for  recycling  are identified.  Current and potential markets for recovered
 materials  in the  United States are described.

 4.1   ALUMINUM
      Aluminum  recycling in  the United States has been very successful.   In
 fact, it has been so successful that Reynolds Metals found it advantageous to
 solicit recycled  aluminum  in the United States rather than continue  alumina
 and  bauxite production overseas.  A further  indication of aluminum recycling's
 success is  found  in U.S. Bureau of Mines statistics  showing 32 percent  of  U.S.
 consumption of aluminum in  1982 was recycled aluminum.
      In 1984,  approximately 1.5 million tons of  aluminum was discarded  with
 municipal waste.  Although  steadily increasing,  the  tonnage of aluminum
 discarded  is small.  About  643,000 tons of aluminum  were recovered in 1984
 from discarded containers  and packaging.  The recovered  aluminum containers
 were  then used to make sheet for new cans.   Recovery of  aluminum waste  is
 expected to continue to grow slowly with the increased demand for aluminum
 cans.  The percent recovery is expected to stabilize at  about 50 percent of
 the cans in the total municipal waste stream.    The  amount of aluminum
 recycled may have little effect on landfill  space,  but revenues generated  from
 the sale of aluminum waste  are high and help to  offset other waste  handling
 and recycling  costs.
     Source separation has  been a major method of  separation of  aluminum cans
 and packaging  from the municipal waste stream.   In addition,  several
 separation processes for recovering aluminum scrap from  mixed  refuse have been
described.   Eddy current  separation has demonstrated  70 to  80  percent
 recovery of aluminum from mixed refuse.  '
                                       4-1

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 4.2  FERROUS  METALS
      Discarded  ferrous  metals  totalled  about 11 million tons in 1984.  Of the
 11 million tons,  about  2.9  million  is estimated to be steel packaging (cans,
 pails,  buckets,  drums).   Steel  once  accounted for all beverage cans but has
 been largely  supplanted by  aluminum.  The percent decline  in the proportion of
 ferrous materials in  municipal  waste is expected to continue.
      Ferrous  metals  are easily removed  magnetically from mixed municipal waste.
 Centralized separation  processes  typically  include an operation for  separating
 shredded ferrous  scrap.   Combustion  operations may separate ferrous
 materials before  combustion or after combustion, when the  metal has  been
 sterilized.   Even though ferrous  scrap  is one of the easily separated constituents c
 mixed refuse  stream,  it is  not an intensively recycled  part of municipal
 refuse.   Franklin Associates  reports a continuing decline in quantities
 recycled,  because other sources of  high quality ferrous scrap are  available  to
 secondary ferrous metal  producers.   This, coupled with  declining demand  for'
 steel,  means  that ferrous scrap recovered from municipal waste is  marginal  in
 the  marketplace.
      One of the major technical problems associated with recycling steel
 packaging  can be  overcome through detinning processes that remove  tin  from the
 scrap,  thereby producing a  high quality scrap and increasing  its utility  for
 use  by  secondary  metals  producers.      An  optimum scheme  for recovery  of
 ferrous  materials is  the separation  of  steel cans from  unburned refuse  after
                                                    Q
 shredding,  followed by  detinning  to  recover the tin.    The scrap can then be
 further  shredded  or compacted  to  make a premium scrap.
      While  the market for shredded  ferrous  scrap recovered from
municipal waste does  not look  favorable nationally, local  market conditions
may make recovery economically feasible.  Location of municipal waste recovery
facilities near detinning or copper  mining  operations may  capitalize on good
local market potential.   For example, New York City,  in developing its
recycling strategy, found one  market for steel cans  in  the local area - a
                                  Q
detinning facility in New Jersey.    The largest use of  recycled  tin cans is in
refining copper ore.  For ores  rich  in  oxides, a leaching  process  based on a
copper-iron ion exchange is  used  with cans  as a source  of  iron.  The demand
for cans to be used in  this  process  is  localized in  Arizona and  Utah.
                                       4-2

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 4.3   GLASS
      Glass  accounted  for  an estimated 14 million tons of waste generated in
 the  United  States  in  1984, or about 9 percent by weight of the total  municipal
 solid waste generated.  The proportion of glass in the waste stream peaked in
 the  early  1980's at  11  percent.  Over the past 5 years, glass containers have
 lost considerable  market  share  to aluminum and plastic containers.  The trend
 is expected to  continue and by  the year 2000, the percentage of glass in the
                                                  2
 waste stream is projected  to fall below 8 percent.
      In  1984, about  1.0 million  tons of glass was recovered for reuse.
 Virtually all of the  recovered  glass was in the form of glass containers
 (i.e., beer and soft  drink containers, wine and liquor bottles, food bottles
 and  jars, etc.).   The primary market for recycled glass containers is the
 glass container manufacturing industry.  Glass manufacturers can  replace  at
 least 50 percent of  their  raw materials with cullet derived from  recycled
 glass containers and  from  scrap  cullet  (i.e., in-house scrap or  scrap
 purchased from  bottling plants).  However, to be  suitable  for use by the  glass
 manufacturing industry, cullet  from recycled glass containers must be
 separated by color (i.e.,  clear, amber, and green) and be  relatively free of
 contaminants such  as  paper, plastic, metals, and  rocks.  Strict quality
 specifications  are maintained by the glass manufacturing industry for  recycled
       11 12
 cullet.  '    For  these reasons, and because raw  materials for making  glass
 are  relatively  inexpensive, most glass manufacturers use no more  than  20
 percent cullet  in  their glass batches.
      Other  markets for  recycled  glass which have  less  stringent quality
 requirements include  manufacturers of glass wool  and certain  building  and
                 14 15
 paving materials.  '    Many of  these markets can accept mixed-color cullet
with  relatively high  levels of  contaminants.   Consumption of recycled  glass
by these markets,  however, is minimal at present.  Efforts to develop  more
fully these  and other markets for used glass by experimental  production and
testing of materials made  from  recycled glass are being undertaken by  the
Bureau of Mines.
                                      4-3

-------
      Glass  containers are recovered for reuse in three ways:  source
 separation, mechanical separation, and reuse programs.  Source separation
 accounts  for the majority of recovered glass containers.     Some processing  is
 typically required to sort the collected bottles by color and to remove
 contaminants before the recovered glass can be turned into cullet for reuse  by
 the  glass industry.  These processing steps have traditionally been performed
 manually.   Recently, mechanical processes have been developed to process
 ".dirty" glass.    Also, processes relying on optical sorting of mixed-color
 glass  into  single-color glass fractions have been demonstrated.  '     In
 general,  though, processing of glass into clean, single-color components is
 likely to continue to be a labor-intensive process.
      Mechanical separation of glass from mixed municipal waste for purposes of
 resource  recovery, or to enhance  the fuel quality of the residual waste, is
 practiced by a number of facilities.  The glass fraction recovered by these
 processes is generally not suitable for use by the  glass container
 manufacturing  industry because it is mixed-color and  has a relatively high
                      12
 level of  contaminants.    Instead, the recovered glass fraction  may  be  used  in
 production  of  various building materials, as an aggregate in  paving  and
 construction projects, or as landfill.   '   '    Mechanical separation of glass
 usually is  achieved by a series of classification  and  separation steps  to form
 a glass-rich fraction which is then subjected to froth flotation to
                               13  19
 concentrate the glass further.  '
      Reuse  programs rely primarily on container deposit  legislation  requiring
 consumers to pay a deposit on beverage containers  which  is redeemed  when the
 containers  are returned to the retailer.  Nine  states  have passed  returnable
 container deposit laws (Section 3.1.1).  An additional twenty-three  states
                                                20
 reportedly  are considering similar legislation.     Bottles collected as a
 result of these laws have the advantage of  being easily  color-separated by
 redemption centers, thereby facilitating their  processing  for reuse  by the
glass container manufacturing industry.  The  impact of container deposit  laws
on overall recycling efforts is uncertain.  Although  these  laws have been
effective in diverting up to 90 percent of  discarded  glass containers from
                                       4-4

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 municipal  waste,  they have  resulted  in  consumers switching to containers that
                                                           21
 are more convenient  to handle  (e.g.,  plastic and aluminum).    Further, they
                                                            22
 have created flooded markets  for  some types of glass cullet.    In New York
 City, for example,  availability of green cullet primarily from imported beer
 bottles has increased significantly  and exceeds current market demand for
 green glass.  In  general, the  increased availability of glass cullet from
 container deposit laws tends  to drive down the price for green and amber
                                                           9
 cullet but has little effect  on    ?ar (i.e., flint) cullet.   The net result
 is  that privately owned recycling businesses which are no longer able to
 collect  ^d process  glass  (and aluminum) containers profitably may decline,
                                                    21
 thus  reducing  recycling efforts for  other materials.

 4.4  PAPER
      Waste paper  and paperboard is the  single largest component of municipal
 waste,  accounting for an estimated 37 percent by weight of total municipal
 waste generated in 1984.    Of  the approximately 62.3 million tons of paper  and
 paperboard  waste  generated  in  1984,  an  estimated 13 million tons, or 21
 percent, was recovered for  reuse.  Both the total amount of waste paper
 generated  and  the amount recycled are expected to increase slowly over the
               2
 next  few years.
      Most  of the  recovered  paper  and  paperboard ^n the United States is  reused
 by  the  paper and  paperboard manufacturing industry.  Of the 600 paper  and
 paperboard  mills  in  the United States,  200 depend exclusively on waste paper
 for raw material  and another 300  mills  use a percentage of waste paper as
                   23
 their raw material.     To make use of recycled fiber, paper and paperboard
 mills require  special  equipment and  facilities to perform pulping,  cleaning,
                                                                           f\ *
 screening,  and refining operations needed to prepare recycled fiber-stock.
 Before recovered  waste paper can  be  used by the paper  industry,  steps  must  be
 taken to remove contaminants  introduced during production  and fabrication  of
 paper products or during the use  of  those products.  Example of  contaminants
 introduced  during production and  fabrication include:   non-emulsifiable
 latexes; plastics laminated to paper; wet strength resins;  nondeinkable  inks,
hot metals  in bindings; waxes, resins and other polymers  for  special  products;
chemical additives;  pressure sensitive  tapes for sealing;  heat  seal  labels;
                                       4-5

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 and some paper coatings.   Dirt,  food, metal, rags, wire, glass, and plastics
                                                               25 ?6
 are examples  of waste  paper  contaminants  introduced during use.  '     The
 ability to use various grades  of waste  paper to replace virgin raw materials
 depends on the type  of paper being manufactured.  For example, mills that
 produce business printing  and  tissue  paper can utilize only the highest
 quality grades of waste paper.   Examples  of these include scrap from
 paper-converting plants and  data processing centers, ledger paper from
 offices,  and  printed bleached  paper that  has been processed at a deinking
 mill.   Bulk grades of  waste  paper, including recycled newspaper, corrugated
 boxes,  and mixed office waste  paper,  are  used by mills that make newsprint,
                                    g
 paper board,  and construction  paper.
     Source separation is  the  most prevalent method of recovery of waste paper
 for reuse  by  paper and paperboard mills.  Most notably, source separation  is
 used to  recover newspaper, corrugated boxes, and high grade office paper.
 Newspaper  is  particularly  well suited for recycling because a competitive
 market  for used newspaper  exists and  because it comprises a significant  enough
 portion of the  municipal waste stream to  afford appreciable landfill savings
               22
 when recycled.     Approximately  3.3 million tons of newspaper was recycled  in
                                                                   P
 1984 corresponding to  abou*  24 percent  of the discarded newspapers.
 Newspaper  collected  by residential source separation programs  is typically
 sold to a  waste paper  dealer who processes the paper by removing contaminants
 and densifying  for bulk resale to paper mills.   Major markets for used
 newspaper  are mills  producing  boxboard  or newsprint and producers of
 specialized construction and building materials.25'26
     Used  corrugated boxes are the largest single source  of waste paper  for
 recycling.     In 1984,  an  estimated 6.8 million tons, or  about  36 percent,  of
 used corrugated boxes  were recycled.2   As with paper dealers  handling  used
 newspaper,  used corrugated cardboard  dealers manually remove  contaminants  from
 the recovered corrugated boxes and perform any additional  processing  required
 by paper mills  purchasing  the  used corrugated paper.  Major markets  for  used
 corrugated  boxes  are paperboard  mills and producers of  specialized
construction and  building  materials.9'26
                                       4-6

-------
      Current  programs  to  recycle high grade office paper are motivated by  the
 relatively  high  value  of  these materials in the waste paper market.   Dealers
 typically pay more  for high grade office paper than for bulk grades  of waste
 paper,  such as newspaper  and used corrugated boxes, because of the capabi,;ty
 of paper mills to use  the waste paper as a direct substitute for wood pulp in
                        Q
 the papermaking  process.   Recycling programs have been established  in a
 growing number of office  buildings to recover the value of their high grade
 waste paper.   In 1984,  about 800,000 tons (16 percent) of high grade office
                          2
 paper waste were recycled.
      Waste  paper recovered mechanically from mixed municipal waste generally
 does  not meet industry specifications for use by paper mills in the
 United  States, although some paper mills have indicated their willingness to
 use waste corrugated boxes and mixed paper recovered from mixed waste that is
                                         26
 predominantly commercial  or office waste.    However, in most cases, the paper
 industry would require waste paper recovered from a mixed waste .stream to
 undergo extensive cleaning and sterilization before it could be used to make
 even  low-grade paperboard.   Other markets with less stringent quality
 requirements  for recovered waste paper from mixed waste streams include
 manufacturers  of cellulose insulation, packing and cushioning materials, and
                  23
 building products.     These markets can accept the lowest grades of waste
                                                           26
 paper and are  an outlet for otherwise unusable paper fiber.    Although
 consumption of waste paper by these markets at present is limited, development
 of these and  other markets for mixed waste paper  is considered an important
 factor toward  increasing  significantly the amounts of waste paper that can be
                                               27
 economically  recycled  and reused in the future.
     Most of  the waste paper recovered in the United States  is consumed  in
 U.S. paper mills.   In  1984, however, an estimated  3.4 million tons  of waste
                                                                  23
 paper was exported for use as raw material in foreign paper mills.
 Estimates of  future exports of waste paper are favorable  in  light of projected
 shortages of  indigenous forest resources  in Europe, Japan,  and other parts of
Asia.  Cities  like New York City are depending on  the expansion  of  foreign
markets to help  absorb the waste paper collected  under  their  comprehensive
                   q
recycling programs.
                                       4-7

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 4.5  PLASTICS
     Approximately 9.7 million tons of plastic waste was  generated  in  the
 United States in 1984, representing about 6.5 percent by  weight  of  the total
 generated municipal waste.  Of the total plastic wastes generated,  plastic
 containers and packaging make up the largest fraction, accounting for  over
 half of plastic discards in 1984.  The amount of plastic  waste discarded
 annually has more than doubled since 1960 and, while still  a small  fraction,
 plastics is currently the most rapidly growing material in the solid waste
 stream.  By the year 2000, discarded plastic containers and packaging alone
 are projected to represent more than 5 percent by weight  of the total  waste
       2
 stream.
     Recycling of post-consumer plastic waste is currently not a common
 practice.  In 1984, less than 100,000 tons of post-consumer plastic was
                         2
 estimated to be recycled.   However, one type of plastic waste is currently *
 the focus of a limited but successful recycling effort.  Polyethylene
 terephthalate (PET), most commonly used in 2-liter soft drink containers, is
 currently being recovered and reused in a variety of  applications.  In  1984,
 an estimated 63,000 tons of PET containers, or about  18 percent of the  total
 PET containers discarded, was recycled.  The primary  source of PET containers
                                                      2
 for recycling was states with container deposit laws.   The principal market
 for recycled PET is polyester fiber staple, used in clothing, pillows or other
 items,  or for glass-fiber products.  Plastic strapping for pallet wrapping is
 another use for recycled PET, but this market is small (5 to  18 million pounds
          28
 per year).     Methods are also under development to convert PET  to polyols for
 •ise in rigid or flexible urethane foams.
     The FDA regulations for food packaging materials preclude  reuse  of
 recycled PET to make new soft-drink containers.  '     Different  processes are
 used by intermediate dealers to process soft-drink  containers for  PET recycle.
These containers typically contain several components in  addition  to  PET,
 including a high-density polyethylene  (HOPE)  base cup, paper  or paint labels,
 and an aluminum and/or plastic cap.  Some processors  separate these  materials
by first removing the cap and base cup  (manually or mechanically),  grinding
the remaining material, and then washing the  ground PET  to  remove  paper and
adhesive.   Another system first grinds  the whole bottles  and  then  passes the
                                       4-8

-------
 ground materials through an air classifier to remove paper,  an electrostatic
 precipitator  to remove aluminum, and a flotation system to separate plastic
 resins.   Both methods are reported to be capable of supplying high purity
      °   Also, the  recovered HOPE may be sold to plastic scrap users for
 production  of  flower pots, plastic tubing and other products as well  as for
                                 29
 the  manufacture  of new base cups.    Recycling of PET containers is expected
 to continue to increase  as additional states pass container deposit laws, and
 as additional  uses for recycled  DJT are identified.
      Several factors contribute  to the overall low level of post-consumer
 plastics  recycling.  Technologies for removal of contaminants in the form of
 metal,  paper,  wood, ceramic,  and other substances which have been  integrated
 into  plastic products have been  slow to develop.     '    Further,  to recycle
 more  post-consumer plastic wastes, the majority of which consist of multiple
 resins, further  technological development is needed  for processes  that
 segregate plastic resins  into homogeneous groupings  or for end  uses which can
 utilize mixed  resin scrap.  Processes that  separate  mixed plastic  wastes into
 recyclable  fractions or  that  use mixed resin scrap for manufacturing new
                                                             931
 plastic products are practiced on a limited scale  at present.      For
 example, the Sorain-Cecchini  process described in  Section 3.2.2  is capable  of
 separating  and recovering so-called film plastic (i.e., low density
 polyethylene)  from other  plastic waste by a series of air classification
 steps.  The recovered film plastic is either baled and sold to  the injection
 and compression molding plastic  industry or formed into pellets  and combined
with  5 to 10 percent of virgin materials to make new film plastic.  The
remaining plastic wastes  (i.e.,  PVC, PET) are not  currently salvaged by  this
                                                                32
process, but some could be recovered through source  separation.
     One suggestion for improving the ability to recycle plastic products  is
to require manufacturers  to label clearly plastic  products  so  that the
consumer could identify easily the type(s)  of resin  contained  in the plastic
product.  This would facilitate  recycling of plastic waste  by  source
separation because the consumer would be able to segregate  plastic waste into
single-resin components.
                                       4-9

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      Emphasis  has  also been placed on developing techniques for processing
 recovered mixed plastic waste  into a reusable form.  One process in use is  the
 Reverzer process,  developed by Mitsubishi Petrochemical in Japan,  which
 utilizes mixed thermoplastic wastes with up to 20 percent non-thermoplastic
 materials (e.g., paper) to make extruded and molded plastics products with
 thick cross  sections.  These products include fence stakes, irrigation pipe,
 pallets, part  benches, road drains, cable drums and building panels.  At least
 30  companies worldwide reportedly are using this technology to make plastic
 products.  Other processes include: (1) the Japan Synthetic Paper process
 which compression  molds film scrap (from mixed plastics) with wood chips to
 make  chip/wall board, and  (2)  the Regal Packaging process which first
 granulates mixed plastic wastes and then fuses the granules with heat  into
 sheets used  in compression molding to produce a variety of plastic products.
 The latter technology is reportedly capable of handling plastics with  paper,
 metal, glass,  and  sand contamination.

 4.6   WOOD
      Discarded wood wastes comprised to about 5.1  million  tons  in  1984.  Wood
 waste removed  from the waste stream reportedly has been  sold  as wood  chips for
               34
 firing boilers.    Waste wood  recovered from  refuse  also  has  been  used to  make
           34  35
 paper pulp.  '
      In San  Francisco, wood  is reported to  be separated  by hand from
 construction delivery boxes.   After the wood  passes  through  a hammer mill  and
 grinder, the wood  chips are  sold  for boiler fuel.  Tree  branches  from city
 parks  and from tree pruning  companies are also processed  in  this  way by two
 companies that began work  in 1984.  Recycling  wood  from construction waste  in
 this  manner results in a significant reduction  in  wood waste to be landfilled
 and is reported to be a lower  cost alternative to  landfilling.

 4.7   RUBBER
     Gross discards of rubber  products  in 1984 comprised 1.9 million tons, of
which 1.2 million  tons were  tires and tire  products.   Tonnage of  discarded
rubber tires has been declining with decreasing  car  sales and the advent of
smaller and more durable tires.   Small growth  in discards is anticipated as
                                       4-10

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                                                                        2
 car sales increase with  the  increase  in  number of people of driving age.
 Recovery of tires  for reuse  or  recycling  accounted for 5.2 percent of discards
 in 1984, down from 20 percent  in  1960.   Thirty-three thousand tons of tires
 was retread in 1984,  and rubber recovery  for other uses amounted to 103,000
      ?
 tons.
      Recycling options for rubber tires  include retreading and rubberized
 asphalt.    Rubber asphalt mixtures have  been demonstrated in Arizona to
 extend substantially  pavement  life and reduce the amount of resurfacing
          42
 required.    The Danish  government is reportedly considering using discarded
                         38                             9
 tires  in highway asphalt  ,  as  is the city of New York.   However, analysts
 have not seen an optimistic  future for recycling rubber products.
     Tire disposal  presents  problems  because landfill ing is an inefficient use
 of landfill  space,  and tires are  non-biodegradable.  Air trapped  in tire rims
 causes the tires to rise to  the surface.  Burning tires in regular combustion
 equipment can cause high levels of sulfur emissions  and black, sooty-laden
 smoke.   Many old tires are stacked outdoors where they can harbor  rodents  and
         43
 insects.     Shredding is one procedure that can reduce the volume  required  in
 landfill ing.   New  York City  is  currently using  shredded tires  as  a part of
                           40
 their  daily landfill  cover.     Combustion of shredded  rubber or whole  tires  in
 specially designed equipment as a cheap  energy  source  is receiving attention
 as a disposal  method,  thus reducing required landfill  space  and recovering
 energy.16'37

 4.8 COMPOST
     Quantities  of disposed  yard  waste are  poorly documented  and  vary  widely
 across  the United  States.  Disposed yard waste  was  estimated  in  1984  to be
 23.8 million tons.  Some yard  waste is composted but the quantity is  not known
                                                                2
 and is  expected  to be small  compared  to  the total waste  stream.
     There are reportedly numerous composting  facilities  in  rural  Germany.38
Markets  for  compost exist in Rhineland vineyards, gardens,  parks,  and
orchards.   In  the  United States,  the  city of San Francisco  has established
production of compost  from zoo  animal bedding  and manure.   The composted
materials  is marketed  commercially as "Zoo  Doo."  San  Francisco  is also
reportedly planning composting  for tree  trimmings,  leaf  litter,  and  grass
clippings  from Golden  Gate Park for use  on  city parks  and  golf courses.
                                      4-11

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     In New York City, low grade compost is being used as landfill cover.
This measure is a volume reduction measure because cover material consumes
                                              39
about 70 percent of available landfill volume.    Compost is also being
produced in Berkeley, California in a centralized city compost facility.
     Producing a refuse material for composting requires several processing
steps aimed at reducing the size of the refuse components and separating
compostable materials from other materials.  One recommended system  ncludes
the following steps: 1) shredding, 2) magnetic separation of ferrous
materials,  3) air classification to remove a large portion of heavy
inorganics, and 4) screening to removal grit, glass, and small hard
particles.44
                                       4-12

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 4.9   REFERENCES

  1.   Cutter,  Susan.  Resource Recovery, An Overview in Environmental  Policy:
      Solid  Wastes.  Volume  IV.  Ballinger Publishing Company, Cambridge,
      Massachusetts.  1985.

  2.   Franklin Associates, Ltd.  Characterization of Municipal Solid Waste in
      the  United  States,  1960 to 2000. Final Report.  EPA Contract 68-01-7037,
      Work Assignment 349.   July 1986.

  1.   Pettit,  C.  L. Trends in Collecting Recyclables.  Waste Age.  Vol 17, No.
      " July 1986.  pp 49-56.

  4.   Makar,  H.V. and R.S. DeCesare.  Unit Operations for Nonferrous Metals
      Recovery.   Resource Recovery and Utilization, ASTM STP 592, American
      Society  for Testing and Materials, 1975, pp 71-88.

  5.   Kenny,  Garry, and Edward J. Sommer, Jr.  A Simplified Process for Metals
      and  Noncombustible Separation from MSW Prior to Waste-to-Energy
      Conversion.  ASME Meeting, Orlando, Florida. June 3-6, 1984.

  6.   Interrant, C.G. Report on the Ferrous Metals Workshop in Resource
      Recovery and Utilization, ASTM STP 592,  American Society  for Testing and
      Materials,  1975, pp. 146-152.

  7.   Groetsch, J.G., Jr.,   R.C. Gabler, Jr., and D.A. Wilson.   Electrostatics
      stripping of Tin in an Acid Fluoroborate Electrolyte.  Report of
      Investigations 8887.   U.S. Department of the Interior.  1984.

  8.   Kaplan, R.S.  Deterrents to the Recycling of Ferrous Scrap from Urban
      Refuse  in Resource Recovery and Utilization, ASTM STP 592,  American
      Society for Testing and Materials, 1975, pp. 91-105.

  9.   The Waste Disposal Problem in New York City: A Proposal for Action.
      Volume 7: Recycling Strategies.  Supplement to Preliminary Planning
      Report Submitted to the Board of Estimate in April  1984 by the  Department
      of Sanitation in Response to a Resolution (Calendar No. 87) Adopted  by
      the Board on June 16,  1983.

10.  Miller, Robert E. and  Oscar E. Dickerson.  Management of  Solid  Waste in
      Cold Regions: Resource Recovery Potential in  Proceedings  of Third
      Symposium on Utilities Delivery in Cold Regions.  May 25-26,  1982.

11.  Scientific Energy and  Recycling Group,  Inc.   Resource Recovery:
      Experience and Systems Description,   [no date]

12.  Seeley, C.E. Glass in  Solid Waste Recovery System:  Resource Recovery and
     Utilization, ASTM STP  592,  American  Society  for  Testing  and  Materials,
     1975, pp. 114-121.
                                      4-13

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 13.  Archer, Tom and Jon Juls. RCRA Study of Glass and Plastic Resource
     Recovery.  Proceedings of the Seventh Annual  Research Symposium,
     EPA-600/9-81-002C.  March 1981.

 14.  Scott,  Pickett.  Report on the Glass Workshop.  Resource Recovery and
     Utilization, ASTM SIP 592, American Society for Testing and Materials,
     1987,  pp.  159-164.

 15.  Stanczyk,  Martin H. and Roger S. DeCesare.  Resource Recovery from
     Municipal  Solid Waste.  U.S. Department of Interior: Bureaus of Mines.
     Bulletin 683   1985.

 16.  Bronstein, Scott.  Where, Oh, Mere to Empty the Trash?  The New York
     Times.  September 14, 1986 p. 6F

 17.  Boyhan, George E. and S. Sengupta, eds.  Waste Disposal and Resources
     Recovery.  (Dade County), Inc. in 2nd Conference on Management of
     Municipal, Hazardous & Coal Wastes:  Proceedings.   Resource Recovery,
     Inc.   Miami University, Miami, Florida.  September  1984.

 18.  Mahoney, Ps:rick F.  There's Gold in That There Ash!  Waste Age, Vol. 17,
     April  1986.

 19.  Marsh,  Paul.  Recycling:  Glass in Kirk-Othmer, Concise Encyclopedia of
     Industrial Technology.  John Wiley & Sons, New York.  1985.

 20.  Plastics Recycling: A Revival. Chemical Engineering. June  25,  1984.
     pp. 22-26.

 21.  Clapham, W.B.  An Analyses of the Potential  Effect  of Beverage Container
     Deposit Legislation on Municipal Recycling Programs.  Journal  of
     Environmental Systems Vol 14, 1984-85.

 22.  Five Perspectives on a Hot Topic.  Waste Age.  Vol  17, No.  7,  July  1986.
     pp. 29-37.

 23.  Twelve  Facts About Waste Paper Recycling.  Distributed by  the  American
     Paper  Institute - Paper Recycling Committee.  1985.

 24.  Robins, James H. and James R. Grant. Recycling:  Paper.   Kirk-Othmer,
     Concise Encyclopedia of Industrial Technology. John Wiley  i Sons,
     New York,  1985.

25.  How to  Recycle Waste Paper.  Distributed  by  the  American  Paper Institute
     -   Paper Recycling Committee.  1985.

26.  Arnold  E. W.  Report on the Paper Workshop.   Resource  Recovery and
     Utilization.  ASTM STP 592.  American  Society for  Testing  and  Materials,
     1985, pp.  177-184.
                                       4-14

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 27.   Graminski,  E. L. Problems and Potentials in Paper recycling.   Resource
      Recovery  and Utilization, ASTM STP 592, American Society for Testing  and
      Materials.  1975 pp.  132-139.

 28.   Lipsky, Richard.  The Collection, Processing Of, and Markets For,  Post
      Consumer  PET, New York State Legislative Commission on Solid Waste
      Management  Conference on Materials Recycling and Composting.   Albany,
      New  York.   October 9, 1985  as cited in Hinchey, Maurice D., Chair.  The
      Economics of Recycling Municipal Waste.  Staff report to New York State
      Legislative Commission on Solid Waste Management.  Albany, New York.
      1986.

 29.   PET  Plastic Recovery.  Resource Recycling.  Vol  II, No. 1  March/
      April  1983, pp. 17-19, 35.

 30.   Plastics  Recycling.  Viable  Means of Energy Conservation.   Resource
      recovery  Update. Vol  10, No. 5.  May  1981.

 31.   Hellman,  Eric.  Plastics Recycling: Understanding  the Opportunities.
      Prepared  for the Toronto Recycling Action Committee.  December 1981.

 32.   KLES  Incorporated.   Sorain  Cecchini:   Energy and Materials from MWS.
      No date.

 33.   Ingle, G.W.  Report  on the  Plastics Workshop.   Resource Recovery  and
      Utilization, ASTM STP 592,  American Society for  Testing and Materials,
      1975,  pp. 165-176.

 34.   Zerbe, John.  Wood Products Laboratory.  Telecon.   Conversation with
      G. E.  Wilkins, August 25, 1986.

 35.   Carr,  Wayne. Telecon. Conversation with G.E. Wilkins.  August 27,  1986.

 36.   Cotter, Daniel A.  San Francisco's Integrated  Recycling Program  in
      Proceedings of the Twelfth  Biennial Conference,  1986 Waste Processing
      Conference.  ASME.   Denver,  Colorado.  June 1-4,  1986.

 37.   Goddard, Haynes C. Options  for Resources Recovery  and  Disposal of Scrap
      Tires: A Review of Technologies and Economics  in Municipal Solid  Waste
      Resource Recovery in Proceedings of the Seventh  Annual  Research
      Symposium,  EPA600/9-81-002C.  March 1981.

38.   Hinchey, Maurice, Chairman  New York State  Legislative  Commission  on  Solid
      Waste Management in  Norway,  Sweden, Denmark, and Germany:  Lessons for  New
      York.  December 1985.  Albany, NY.

39.  A Status Report on Materials Recycling Activities  in  New  York City.   City
      of New York Department of Sanitation.  December 1985.

40.  Taldone, Vincent. Telecon.   Conversation with  G.E. Wilkins,  Radian
     Corporation.  September 8,  1986.


                                      4-15

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41.  Buchanan, Marc.  Recycling Yard Waste in California in Biocycle.   V.  25
     No. 8 Jan-Feb. 1984.  pp. 40-41.

42.  Scrap Tires:  A Resource and Technology Evaluation of Tire Pyrolysis  and
     Other Market Alternative Technologies.  Idaho National Engineering
     Laboratories.  Idaho, 1983 as cited in Hinchey, Maurice D., Chair.  The
     Economics of Recycling Municipal Waste.  Staff Report to New York State
     Legislative Commission on Solid Waste Management.  Albany, New York.
     1986.

43.  Berling, J.  A Potential Public Health Problem Associated With Tire
     Stockpiles.  New York State Legislative Commission on Solid Waste
     Management Conference on Materials Recycling and Composting.  Albany,
     New York.  October 9, 1985 as cited in Hinchey., Maurice D., Chair.  The
     Economics of Recycling Municipal Waste.  Staff Report to New York State
     Legislative Commission on Solid Waste Management.  Albany, New York.
     1986.

44.  Glaub, J.C., L.F. Diaz, and G.M. Savage. Preparing Municipal Solid Wa~ste
     for Composting in Biocycle. V.  25, No. 8.  Nov-Oec 1984.   pp. 32-36.
                                     4-16

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                   5.  EFFECTS OF RECYCLING ON COMBUSTION

      Because  recycling  is  not  expected to completely eliminate the need for
 combustion,  it  is  necessary to consider the effects of  removal  of recycled
 materials  on  waste combustion.   Test  results  show that combustion can reduce
 the  volume  of waste  by  60  to 90 percent.    If a portion of the waste can be
 removed  and  recycled prior  to combustion,  however, a 100 percent volume
 reduction  is  possible. Therefore, the goal in both methods of waste management
 is reducing landfill  space required for waste disposal.
      Waste  constituents  recycling can  reduce  combustion  costs in three ways.
 First,  less combustion  capacity  is  needed and  smaller equipment  usually
 decrease construction costs.  Second,  combustor  residue is  decreased  when
 glass and metals are  removed,  thus lowering operating  costs and tipping fees3.
 Finally, maintenance  cost savings may be realized  if abrasive waste components
                                          2
 such  as glass, metal  and grit  are removed.
      Two types  of effects  of  recycling on combustion will  be  considered
 briefly in  this  section:   1) effects  of materials removal  on the combustion
 process and  2)  effects of materials  removal  on  emissions  from  combustion.
 Much  of this  section is based  on  logic and supposition.   Little  data  were
 found  to   determine   what  effect  intensified  recycling will  have  on
 refuse combustion.

 5.1   EFFECTS  OF RECYCLING ON THE COMBUSTION PROCESS
     When considering the  effects of  materials  removal from the municipal
waste  stream  available  for combustion,  it  is   useful  to identify  two
categories of waste constituents, combustible and non-combustible,  because  the
combustion process acts  only on the combustible  portion to  effect a volume
reduction.   The  non-combustible portion may  also be changed chemically  and
physically by the process and  may affect  the  operation,  but it  is not actually
combusted.
aTipping fees are the fees charged by  a  waste  handling facility to accept
 waste.
                                       5-1

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      It  appears  logical  that  removal  of  non-combustibles would  not  adversely
 affect  the  combustion  process.   Removal  of  significant  quantities of  metals,
 glass  and  grit  should,  in  fact,  decrease slagging and clinker  formation
 through  removal  of substances that form slag and clinkers.   Decreased  slagging
 and  clinker formation  should  then,   in  turn,  improve  combustor  on  time
 availability and improve overall combustor operations and performance.
      Few data  were  found that could  be  used to  affirm  or  deny this  logic.
 Data  concerning  combustion of processed waste such as RDF to unprocessed waste
 are largely noncomparable because of  differing combustor designs.   However, a
 series  of  tests  run  at a rotary combustor  designed  for mass  firing was
 performed to determine what effects  non-combustibles removal  has  on  energy
 recovery from  refuse.    The  tests  showed removal of glass, grit, and metals
 resulted in  reduced  clinker formation and  slagging and improved combustor
 availability of  up to  40 percent;  long-term availability was  increased by 20
 percent.  The  comparative  tests of processed versus non-processed  fuel  also^
 showed improved  feed and ash handling, and  steam generation rates were  higher
 and more consistent.
     These few data would tend  to  support the  logical  deduction that removal
 of non-combustibles  from refuse may  improve combustor performance.   Other
 benefits, as mentioned previously,  include  improved equipment  life and the
 ability  to  use  smaller combustion  equipment  due  to   processing  smaller
 quantities  of  waste.   Also, the  remu/al  of noncombustibles  would  tend to
 increase the heating  value  of the waste, and therefore allow more  efficient
combustion.
     Removal of  combustibles,  on the other  hand, would remove constituents
that support combustion, mostly paper.   (Note: Yard waste  is  also combustible,
but is associated with so much  moisture  that :ombustion is poorly  sustained.
Therefore,   removal  of  yard  waste or other wet  organic  waste would not
generally be considered detrimental  to the  combustion  process.)   It appears
that recycling efforts might compete  for  the fractions  of  the refuse  needed by
the combustion process  to reduce the volume of the remaining  waste.   For,  if
 Slag is rock-like mineral material  formed  by  the  melting and subsequent
 solidification of ash in a  furnace.  A  clinker is a large solidified mass of
 slag material.
                                       5-2

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 a  heat content high  enough  to  sustain combustion  is  not  maintained,  the
 addition of  fossil fuel may be required to carry out the combustion  process.
 Addition of  fuel would increase the cost of combustion.
      According  to Franklin Associates, municipal waste discarded nationwide  in
 1984  was  composed  of 37  percent paper and paperboard  and  7  percent plastic
 after current  recycling.    Assuming  the  paper fraction has a higher heating
 value 'HHV)  of 7,925 Btu/lb and the  plastics  fraction has a HHV of 11,708
 Btu/lb and assuming  the total  w  -te  has a higher  heating value of 4,50u
 Btu/lb, it can  be  seen that  in  excess of 80  percent of the heating  value may
 be  found in  the plastics and paper in the waste available for combustion, with
 most  of it in the paper fraction.
      Based on  the  previous discussion,  paper  is  the  combustible component
 which  would  be most  likely removed for  recycling  in the near  future.   For
 purposes of  combustion, paper is an important  constituent  in the waste.  It  is
 estimated  that  about half  of  the wastepaper  generated each year  in  the  -
 United States  is not recyclable, either because the paper  is too contaminated,
 having been  used  in  some way  that  precluded  its recovery  from the refuse
 stream, or because it  is  uneconomical to collect.   Even so, removal of  half
 the paper  (using national  average  figures)  and  holding  everything else
 constant,  would reduce the HHV of the waste  to about  3750  Btu/lb, a reduction
 in heating value of  17 percent.  The  value of 3750  Btu/lb is about the  lower
 limit  of the value  required to sustain  and  complete  combustion for current
 combustor designs.  Though this heating value  would likely still be  sufficient
 to support combustion, it may not be  high enough to allow  combustion practices
 that minimize  organic  emissions  to  be achieved.  Therefore, combustion  of  a
 low heating  value waste  would probably require the  addition of supplemental
 fuel to meet guideline requirements.
     Though  removal  of some combustibles  may adversely  affect combustion,
 refuse and local market  conditions  are  highly variable,  and the effects of
 removing paper or other combustibles  from waste that is to be  incinerated has
 to be  considered on  the  local  level.   The fact that  recycling programs also
may include  removal of noncombustibles must  also  be considered.  For example,
 in plans for solid waste management,  Essex County  in  New  Jersey analyzed  the
effects of a planned materials  recovery program on  a planned  combustor.
Essex  County's analysis showed that in that  particular situation,  using
                                   5-3

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 specific  Essex  County  waste  characteristics,  materials  recovery  was  actually
 predicted  to  increase  the higher  heating value of the waste, even with almost
 complete  removal  of  paper.   Essex  County found that the effects  of removal of
 paper  tended  to be offset  by the removal  of glass  and metals which have no
 heating  value.   Similar situations might be  anticipated where RDF  is  being
 produced  for  combustion,  if  recycling  of  paper  is extensive before  the waste
 reaches  the waste-to-energy  facility.
     The  effects  of  recycling on  the fuel value of incinerated waste have been
 addressed  by  one  major manufacturer of waste combustion equipment, Signal
 Environmental  Systems,  Inc.   According  to  this  manufacturer,   an  all -
 encompassing  recycling  program removing both  combustibles and non-combustibles
 should not appreciably  alter the  fuel  value of the incoming waste.  Under such
 conditions, the removal  of non-combustibles  (i.e., glass,  metal  cans,  etc.)
 would  have no effect on thermal  efficiency,  and  on  a per-ton basis, enough
 paper  should  remain  after  recycling  to maintain  present levels of electricity
 and  steam production with  no  requirement  for  auxiliary fuel.   One  study
 estimated  that  a  newspaper recycling program  achieving  25  percent
 participation would  reduce the  fuel  value  of the remaining waste by only 2.8
        2
 percent.

 5.2  EFFECTS OF RECYCLING ON EMISSIONS FROM COMBUSTION
     Removal  of non-combustibles  from the  refuse through  recycling  should
 cause no  increase  in emissions  to the  atmosphere from combustion.  Logically,
 it would seem that removal of non-combustibles  from  the feed to  the combustor
 would decrease  ash quantities to  be disposed  and  particulate  emissions.   Also,
 if the removal  of metals and glass  improves combustion conditions  (Section
 5.1),  lower  emissions of  carbon monoxide  and  organic compounds would be
 predicted.  Results  of tests at the previously mentioned Gallatin,  Tennessee
 facility tend to  support this.
     The  Gallatin, Tennessee conclusion  (Section  5.1) tests also showed
 decreased  lead  and cadmium emissions.  However,  it is  not clear just what
 effects on toxic  metal emissions  can  be  generally predicted.   Toxic  metals
 such as lead, cadmium,  and chromium are found  in significant proportions in
 the  combustible  fraction  of waste  in  the  form of  colorants, paints,
 stabilizers,   and  inks.     Therefore,  removal of  iron,  aluminum, and  other
non-combustibles  from  the waste  may  not eliminate  emissions of  the  heavy
metals from incinerated waste.
                                       5-4

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      The Swedish Environmental  Protection Board has estimated that 5 percent
 of Sweden's annual  cadmium  emissions  can  be attributed to  nickel-cadmium
 batteries;  therefore,  removal of batteries from the waste stream  should result
 in a decrease  in cadmium-containing  ash  and  particulate  matter formed in the
 combustion  process.   Even  more  significant is  the  Swedish government's
 estimate of mercury  emissions  due  to  combustion of alkaline  pyrolusite
 batteries.   Alkaline batteries  contain about 1 percent mercury by weight.    Of
 an estimated 5,400 kg of  mercury  emitted  in 1984 in Sweden, approximately
 2,200 kg was attributed  to combustion  of batteries  and  1,100  kg  to combustion
 of other mercury-containing waste.  With goals of reducing both cadmium and
 mercury levels  1n the Swedish  environment,  a campaign  to  separate batteries
 from municipal  waste has now begun.   Environmental  hazards posed by  batteries
 have also been  noted at  a  combustor  in Wurzburg,  West Germany, where a special
 bin was provided for  battery disposal.    In the  case of mercury emissions,
 these separation practices may  represent the most effective means of reducing
 emissions,  because  test  data Indicate  only 30  to  40 percent control  of mercury
 emissions by available control  technologies (see "Municipal  Waste Combustion
 Study:   Flue Gas Cleaning  Technology.")
      Separation of other  toxic materials such  as paints  and  pesticides,
 possibly could  decrease  the potential  for  toxic materials  emissions  from
 combustion.  However,  the significance  of emissions  decreases  that  could be
 achieved through such measures Is not presently  clear.   Such measures could
 help  diminish,   and  certainly  would  not  be  expected  to  exacerbate,
 environmental effects  of combustion.
      Hydrochloric add emissions  are  also  of  concern   in  the operation  of
 municipal waste Incinerators.   Paper and plastics have  been  shown to be major
 sources  of  chlorine In  the waste and are,  therefore,   assumed  to be  major
 contributors to HC1 emissions.    With  that in  mind,  one may  presume  that
 removal  of  significant quantities of paper  and plastic from the waste stream
 should  reduce HC1 emissions significantly.   But, there are  also  significant
quantities of chlorine In  other parts of the refuse,    such  as  food, so,  it  is
not clear what  effect removal  of  large  quantities  of paper  and plastic would
have on  HC1  emissions from  combustion.   No confirming  data on reducing  HC1
through  removal  of  paper and plastic were found.
                                       5-5

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     Another issue raised with chlorine  in the waste  is  the  question  of  its
contribution  to  the  formation  of  chlorinated  organics,  particularly
chlorinated dibenzo-para-dioxins (CODs) and chlorinated dibenzofurans  (CDFs),
in the combustion process.   The  presence  of  CDOs  and  CDFs in emissions  from
municipal waste combustion  is  well  documented.    However, despite  extensive
study, the mechanism  (or mechanisms)  leading  to formation  of these  compounds
is  not  well  understood.    A  discussion   of  potential  COO/CDF  formation
mechanisms is  given  in  the  volume  titled "Municipal  Waste Combustion  Study:
Combustion Control of Organic Emissions."
     The potential for  PVC-bearing  wastes to act  as  a precursor for  CDD/CDF
emissions  from municipal waste  combustors  has  been  studied  by several
researchers.   Swedish laboratory experiments  demonstrated  that  CDDs and  CDFs
                                                12
are formed from PVC  under  pyrolytic conditions.     Furthermore, in research
sponsored  by   the Ontario  Ministry of  the  Environment  and  conducted by
F.W. Karasek at the  University  of  Waterloo   in Ontario,  Canada-,  catalytic -
formation of CDDs and CDFs  was observed  when the  thermolysis products of PVC
                                    o                                  14
combusted in air were heated to  300 C  in  the presence  of clean  flyash.     The
results of these experiments have not yet been published,  pending attempts  to
reproduce these findings.
     Despite these findings which tend to link PVC with  CDD/CDF formation,  it
is unclear  how separation  and removal of PVC-bearing waste would affect
emissions of CDDs  and CDFs  from municipal waste  combustors.  In one recent
study, flyash  samples from  6 municipal waste combustors  in  4 countries  were
collected  and   analyzed  for  CDOs   and  COFs   using  the  same analytical
procedures.     The lowest  concentrations of  CDOs  and CDFs were found  in  a
flyash sample  from a Japanese waste combustor where refuse was  first  sorted to
remove metal and  plastic wastes  before combustion.  The remaining  facilities
burned unsorted waste.  Although the  COD and CDF  concentrations were  found to
be lower in the Japanese combustor  flyash samples,  the isomer patterr.^  in all
of the combustor flyash samples  were  found to be  similar, indicating that the
same basic  mechanisms  and  precursors were   operating  at all  facilities.
Swedish researchers also noted a similarity   in the pattern  of  individual  COD
and CDF  isomers measured   in  samples of emissions   from  municipal  waste
combustors and  from  laboratory pyrolysis experiments  involving  PVC and  other
chloroal iphatic compounds,  despite  the wide   variation  in  chlorine  content (1
                l ?
to 90 percent).
                                       5-6

-------
     Research to date has shown that PVC is capable of producing CDDs and CDFs
under  laboratory  conditions.   However,  the  mechanism  by  which  this
transformation occurs  is  not clearly defined.  More  research  is needed to
explain the role of  PVC  and  other potential  pathways and reactants that may
contribute to formation of CDO/CDF  in  municipal  waste combustors.  Based on
the recent studies cited above, it  appears unlikely  that  100 percent removal
of  PVC  and other  plastic waste  materials  from  municipal   waste  before
combustion would eliminate emissions  of CDDs and  CDFs from  municipal  waste
combustors.  For this  reason,  the importance of combustion  optimization  and
effective flue gas controls  as a  means for  reducing  CDD/CDF emissions must
continue to be emphasized.  These measures are described in more detail in two
other volumes titled, "Municipal  Waste  Combustion  Study:  "Combustion  Control
of Organic  Emissions;"  EPA/530-SW-87-021c and  "Municipal  Waste  Combustion
Study:   Flue Gas Cleaning Technology,"  EPA/530-SW-87-021d.
                                      5-7

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 5.3  REFERENCES

  1.  Bozeka, Carl G.  Nashville Combustor Performance Tests in 1976 National
     Waste Processing Conference Proceedings.  ASMI.

  2.  Mazanec, F.J.  Compatibility of Recycling with Resource Recovery.
     Presented at the Fifth National Recycling Congress, September 24-26,
     1986, Seattle, Washington.

  3.  Sommer, Edward J. and Garry Kenny.  Effects of Materials Recovery  on
     Waste-to-Energy Conversion at the Gallatin, Tennessee Mass Fired Faculty
     in ASME Conference.  Or! and-..Florida.  June 3-6, 1984.

  4.  Franklin Associates, LTD.  Characterization of Municipal Solid Waste  in
     the United States, 1960 to 2000.  EPA Contract No. 68-01-7037, Work
     Assignment 349.  July 1986.

  5.  Shapiro, Peter, e_£. aj..  The Integration of Energy and Material Recovery
     in the Essex County Solid Waste Management Program.  Department of
     Planning and Economic Development, Division of Solid Waste Management.
     April 1983.

  6.  Salas, Ada C., David F. Lewis, and Donald A. Oberacker.  Waste-To-Energy
     Facilities:  A Source of Lead Contamination in Municipal Solid Waste:
     Resource Recovery, 7th Annual Research Symposium.  EPA-600/9-81-002C.
     U.S. Environmental Protection Agency, Cincinnati, Ohio.  March 1981.


 7.  Energy From Waste, Chapter 10.  The National Energy Authority and The
     National Environment Protection Board for the Swedish government.
     August,  1986.  Translated by Garden Associates,  Inc.  Edina, MN.

 8.  "The Report of the National Electrical Manufacturers Association Dry
     Battery Section."  January 24, 1985.

 9.  Hinchey, Maurice, Chairman.  New York State Legislative  Commission on
     Solid Waste Management in Norway, Sweden, Denmark, and  Germany:  Lessons
     for New York.  December 1985.  Albany, N.Y.

10.  Churney, K.L., fii aj..  The Chlorine Content of Municipal  Solid  Waste from
     Baltimore County, MD. and Brooklyn, NY.  U.S. Department of  Commerce,
     National Bureau of Standards.  Gaithersburg, MD.   NBS/R 85-3213.
     October 1985.

11.  Konheim, Carolyn S.  fi£ 4]..  Authoritative Answers to  Common Questions
     on Emissions from Resource Recovery Facilities.   Konheim & Ketcham,
     Brooklyn,  N.Y.  October 1986.

12.  Rappe, C.  and K. Ballschmidter.  The  Chemistry  of Dioxins.  Working  Paper
     prepared for the WHO working group on risks to  health  of Dioxins  from
     Combustion of Sewage Sludge and Municipal  Waste.   Naples, Italy.   March
     1986.

                                      5-8

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13.   long,  H.Y.  and F.W. Karasek.  Comparison of PCDD and PCDF in Fly-Ash
     Collected from Municipal Incinerators of Different Countries.
     Chemosphere.  Vol. 15, 1986.

14.   Karasek, F.W. and L.C. Dickson.  Model Studies of the Formation of PCDOs
     during Municipal Waste Incineration.  (In press).  Science.
                                       5-9

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