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Stabilization/Solidification of Salt from a Waste
Incinerator
Milan Vondruska a , Vratislav Bednarik a , Jiri Samsonek a & Joseph Houser a
a Department of Environmental Technology and Chemistry , Faculty of Technology
Zlfn , Zlin , Czech Republic
Published online: 27 Dec 2011.
To cite this article: Milan Vondruska , Vratislav Bednarik , Jiri Samsonek & Joseph Houser (2000) Stabilization/
Solidification of Salt from a Waste Incinerator, Journal of the Air & Waste Management Association, 50:3, 453-458, DOI:
10.1080/10473289.2000.10464026
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TECHNICAL PAPER
Vondruska et al.
ISSN 1047-3289 J. Air & Waste Manage. Assoc. 50:453-458
Copyright 2000 Air & Waste Management Association
Stabilization/Solidification of Salt from a Waste Incinerator
Milan Vondruska, Vratislav Bednarik, Jiri Samsonek, and Joseph Houser
Faculty of Technology Zlín, Department of Environmental Technology and Chemistry, Zlín, Czech Republic
ABSTRACT
in a lan dfill. Due to th e ch em ical com position of th ese
salts, stabilization tech n ology based on th e use of cem en ts
is question able.1,2
A laboratory procedure was developed an d verified for
stabilizin g salt produced by an in dustrial waste in cin era-
tor. Th is procedure is based on salt stabilization by m ean s
of an asph alt bin der. Con ductivity values an d relevan t
an ion con ten ts in leach ates of stabilized waste with an
asph alt coatin g were n ear zero. Th e pH value of th ese
leach ates equaled th e pH value of th e water used, so th at
th e stabilized waste salt represen ted in ert m aterial, pos-
in g n o en viron m en tal h azard. An un usually sign ifican t
reduction in th e volum e of processed salt occurred dur-
in g stabilization . After com pactin g un der 10.4 MPa pres-
sure, the volum e of test specim ens was alm ost 55% sm aller
th an th e in itial salt volum e. In practice, th is would m ean
m ore th an a doublin g of lan dfill waste capacity. Volum e
reduction was successfully explain ed by m ean s of a m ath -
em atical m odel.
Th e work presen ted h ere describes a S/S procedure
usin g an asph alt bin der with positive features already dis-
cussed in previous work.3 All in dication s are th at asph alt
bin der, as a h igh ly h ydroph obic substan ce, form s a com -
plete im m obilizin g barrier capable of very efficien tly pre-
ven tin g water leach in g of pollutan ts from stabilized waste
in to th e en viron m en t. Asph alt bin der is m arked by favor-
able properties such as creep, in ertn ess, an d stability in
th e en viron m en t. Th e use of an asph alt bin der presen ts
econ om ic advan tages due to its capability of bein g m ass-
produced an d its soph isticated an d broad application in
tech n ical practice.4,5 Lon g-term strategic forecasts assum e
an abun dan ce of asph alt in th e future. On th e oth er h an d,
wh en usin g asph alt for stabilization , th e crucial observ-
able quan tity is th e con ten t of water-leach able organ ic
pollutan ts (PAHs, ph en ols, an d n on polar h ydrocarbon s).
At presen t, m ost tech n ologically applied asph alt is pro-
duced from crude oil by gradual distillation of in dividual
fraction s, begin n in g un der atm osph eric pressure an d fin -
ish in g in a vacuum at tem peratures up to 350 °C. Asph alt
is th us a relatively pure bin der because it con tain s very
sm all proportion s of ch em ical com pon en ts with boilin g
poin ts below 300 °C. In addition , a select type of asph alt
can be em ployed for S/S tech n ologies an d m ay be furth er
oxidized by th e blowin g process.6,7 Th e m ost im portan t
aspect, h owever, is th e above-m en tion ed h ydroph obic
quality of asph alt, wh ich preven ts leach in g of an y pollut-
an t with water. In th is regard, it is en couragin g th at n atu-
ral asph alt deposits th em selves do n ot h ave a toxic effect
on th e en viron m en t.
INTRODUCTION
Salts produced in waste in cin erators represen t a loose an d
dusty secon dary waste. For a n um ber of reason s (e.g., th e
variability of in cin erated waste leads to variation in salt
com position s an d pollutan t con ten ts), it h as been im pos-
sible to utilize th is waste in a reason able m an n er. It m ust
un dergo stabilization /solidification (S/S) before disposal
IMPLICATIONS
This paper is intended to provide a basis for the stabiliza-
tion of salt produced by solid waste incineration. These
salts represent multi-contaminant waste, almost entirely
soluble in water, whose chemical composition is depen-
dent on the type of waste incinerated at that particular
time. The successful stabilization/solidification (S/S) of
such waste by means of cement binders is uncertain. It is
evident that satisfactory S/S can be achieved by only using
a universally effective method. Asphalt application appears
to be an economically acceptable possibility. This binder
represents an industrial product, and, as the results of
leaching tests have demonstrated, it is capable of per-
fectly stabilizing and solidifying salts. Furthermore, a sig-
nificant decrease in the stabilized salt volume has been
achieved, which is a great advantage due to the lesser
landfill space required.
EXP ERIMENTAL W ORK
Wa st e
Th e processed waste was salt from an in dustrial waste
in cin erator in th e town of Ch ropyn e, Czech Republic.
Th e in cin erated wastes were m ain ly PVC, polyureth an e
syn th etic leath ers, oils, solven ts, an d so on . Th e ch em i-
cal com position of th e salt con sisted predom in an tly of
sodium ch loride an d sodium sulfate. Th e salt sam ple was
Volume 50 March 2000
Journal of the Air & Waste Management Association 453

Vondruska et al.
prepared by passin g it th rough a sieve of about 2-m m
m esh an d h om ogen izin g it by m ixin g in a closed vessel
for several h ours. Th e treated sam ple h ad an apparen t
den sity of about 0.476 g/cm -3, was 99.3% dry solids, an d
con tain ed about 2.3% water-in soluble substan ces. Salt
from in cin erators represen ts a h azardous waste because
it is alm ost en tirely water-soluble an d in its dry state,
owin g to its low apparen t den sity an d sm all particle size,
is rath er dusty.
Asp h a lt Bin d er
Th e asph alt bin der used was Parafix, a product of th e
Param o Com pan y, Pardubice, Czech Republic, an d was
th e sam e bin der used in our previous paper on stabiliza-
tion of toxic in cin erator ash .3
Lea ch in g Test s
Leach in g param eters were establish ed accordin g to valid
legislation of th e Czech Republic, wh ich is derived from
th e European test DIN 38414-S4. Th is test in volved th e
addition of distilled water to th e sam ple in th e ratio of 1 L
water to 100 g dry m aterial. After 6 h r of sh akin g an d an
18-h r rest, th e leach ate was filtered (usin g a 0.7–1.3-µm
fin e glass fiber filter with out an y bin der) an d subjected to
ch em ical an alysis.
P r ep a r in g Test Sp ecim en s of
Figure 1. Block diagram of the stabilization/solidification of salt from
St a b ilized Sa lt Wa st e
a waste incinerator.
For preparation of test specim en s, th e in ten ded quan tity
of bin der was placed in a m ixin g vessel. Th is bin der m a-
terial was carefully h eated an d con stan tly stirred un til
m elted. A calculated quan tity of salt was th en poured in to
th e m elted asph alt, an d th e m ixture was con tin uously
stirred un til all th e salt was in corporated. In th is m an n er,
a powdery blen d was form ed from wh ich test specim en s
were com pacted (at a pressure of 10.4 MPa for 30 sec).
Th e pressed test specim en s were form ed in to a cylin drical
sh ape with a base diam eter of about 60 m m an d a h eigh t
of 20 to 25 m m . Th e weigh t of each test specim en was
about 100 g. For th e purpose of volum e balan ce, th e di-
m en sion s of th e prepared test specim en s were m easured
with accuracy to 0.1 m m .
Det er m in in g An ion Con t en t s in Lea ch a t es
An ion con cen tration s in leach ates (ch lorides an d sulfates)
were determ in ed by an ion ch rom atograph y m eth od us-
in g a Waters liquid ch rom atograph (LC Module I) with a
con ductivity detector.
RESULTS AND DISCUSSION
Lea ch a b ilit y P a r a m et er s of t h e Wa st e
As Table 1 sh ows, n o pron oun ced quan tities of im portan t
organ ic pollutan ts were foun d in th e in cin erator salt
leach ate sam ple. Th e fact th at in cin erator salt con tain s
practically n o organ ic m atter can be explain ed as follows:
m ost organ ic substan ces were burn ed away durin g waste
in cin eration . Of th e sm all quan tity of organ ic substan ces
th at en ter flue gases, on ly a sm all part is caugh t in th e
sodium h ydroxide absorptive solution , probably due to a
saltin g-out effect. Wh en th e absorptive solution is dried
in a spray dryer, volatile substan ces evaporate, an d on ly
m in im al quan tities rem ain in th e salt. Alth ough n o
m arked quan tities of m ajor pollutan ts were foun d in th e
salt sam ple, it should be understood that, contrary to other
h azardous wastes con tain in g pollutan ts in un acceptable
con cen tration s, in cin erator salt is com posed of practically
For m in g t h e Asp h a lt Coa t in g on Test
Sp ecim en s of St a b ilized Wa st e
Test specim en s were h un g on polyam ide fiber an d dipped
in to m olten asph alt bin der for th e sh ortest possible tim e.
After dippin g, th e excess bin der was allowed to drip off
th e specim en , wh ich was left h an gin g un til th e asph alt
coat solidified. In th is m an n er, an asph alt coatin g about
1 m m th ick was form ed on th e stabilized waste test speci-
m en s. A block diagram of S/S tech n ology for treatin g salt
is presen ted in Figure 1.
454 Journal of the Air & Waste Management Association
Volume 50 March 2000

Vondruska et al.
Table 1. Values of selected leachability parameters of waste and binder.
Parameter
Conductivity (mS m )
Waste
Binder
-1
a
1,637
0.419
b
-1)
Soluble substances (mg L
97, 700
9.96
pH
6.37
0.12
-1
NES (mg L )
0.14
-1
PAH (ng L )
31.8
270
b
-1
BTX (mg L )
0.015
0.008
-1
Phenol index (mg L )
0.002
NES = nonpolar extractable substances; PAH = polycyclic aromatic hydrocarbons; BTX
= benzene, toluene, and xylene; aConductivity of salt leachate diluted tenfold; bValues
not determined.
Figure 2. Dependence of leachate conductivity on binder content in
asphalt-coated test specimens; I/I = the value limit of leachate
conductivity for leachability class I/I, which meets limits for landfill
disposal of inert materials (legislation of Czech Republic).
100% pollutan t, an d, as h as been sh own , 97.7% of th is
in cin erator salt sam ple is water-soluble.
Th e leach ate of th e PARAFIX asph alt bin der m eets
m ost param eters of Class I/I leach ability (legislation of
th e Czech Republic), wh ich relates to th e lan dfill disposal
of in ert m aterials. As sh own in Table 1, th e con ductivity
values an d leach ate pH are practically iden tical to th ose
of distilled water. Th e n egligible PAH con ten t in th e as-
ph alt bin der also m akes it very favorable for use.
Lea ch a b ilit y P a r a m et er s of St a b ilized
W a st e Test Sp ecim en s
After a n um ber of trials with prepared m ixes, test speci-
m en s were prepared con tain in g 10–50% bin der. Th ese
specim en s were coated with asph alt, an d th eir leach ates
were collected. Th e con ductivity an d pH values of th ese
leach ates were m easured, an d con cen tration s of ch lorides
and sulfates were determ ined by ion chrom atography. The
depen den ce of con ductivity, pH, an d ch loride con ten t in
leach ate on th e con ten t of stabilized waste bin der is de-
picted in Figures 2–4. The sulfate concentrations have been
om itted sin ce th eir depen den ce was an alogous to ch lo-
ride ion depen den ce. It is eviden t th at th e con ductivity
of leach ate, as well as ch loride con cen tration s in leach ate,
decreased to n egligible values with all test specim en s. Th e
leach ate pH values were also n ear th e pH of th e distilled
water used. Sin ce test specim en s con tain in g 15% bin der
produced leach ate con ductivity lower th an specim en s
con tain in g 20–36.5% bin der, it follows th at th e leach abil-
ity of salt from a stabilized waste specim en coated with
asph alt depen ds on th e quality of th is coatin g, rath er th an
on th e stabilized waste bin der con ten t. It is also worth
m en tion in g th at th e con n ection between ch loride con -
cen tration s in leach ates an d th e con ductivity of th ese
leach ates is perfectly lin ear.
Figure 3. Dependence of leachate pH on binder content in asphalt-
coated test specimens.
EPA lim it for drin kin g water: 250 m g/L
Figure 4. Dependence of leachate chloride concentrations on binder
content in asphalt-coated test specimens; I/II = the value limit of chloride
concentrations for leachability class I/II, which meets limits for landfill
disposal of inert materials in cases when waste comes into contact
with ground water (legislation of Czech Republic).
Th e leach ate pH values in dicated in Figure 3 deserve
special atten tion . It sh ould be realized th at th e leach ate
pH value of n on stabilized salt is about 10.0 (Table 1). Th e
Volume 50 March 2000
Journal of the Air & Waste Management Association 455

Vondruska et al.
-3)
Table 2. Measured densities (kg m of waste and binder.
fact th at th e leach ate pH values of stabilized waste test
specim en s covered with asph alt coatin g were practically
iden tical to th e pH values of th e distilled water em ployed
in th e preparation of th ese leach ates, in our opin ion , is of
fun dam en tal sign ifican ce. Hydrogen (H+) an d OH– ion s
possess ion m obility values (an d th us ion con ductivity)
greater th an th ose of all oth er ion s by alm ost on e order. If
th e pH values of stabilized waste leach ates m ain tain th e
pH value of water used, it is com pellin g proof th at th e
asph alt coatin g provides an excellen t im m obilizin g bar-
rier against perm eation and therefore leaching of any ion.
Using the Atom ic Absorption Spectrom etry m ethod, m an-
ganese, iron, and zinc were sought in the stabilized waste
leachate with the greatest conductivity. Since no traces were
found in the leachate despite a very low lim it of detection
(especially with zinc), other m etals were not sought.
Besides th e leach ability param eters presen ted in Fig-
ures 2–4, th e n on polar substan ce con ten t was determ in ed
in th e test specim en leach ate con tain in g 20% bin der. A
value of 0.08 m g/L-1 was m easured, correspon din g to Class
I/I leach ability (legislation of th e Czech Republic). A com -
parison of th is value with th e n on polar substan ce con -
ten ts in th e waste leach ates an d in th e bin der alon e (Table
1) sh ows th at th is leach ability param eter im proved. Th is
im provem en t probably occurred because th e stabilized
waste test specim en was com pressed an d th us h ad a
sm aller specific surface area th an pieces of asph alt bin der
of th e sam e m ass.
Quantity
Symbol
Average Value
Standard
Deviation
of 3 Measurements
Apparent density of
incinerator salt
ρ’
476
3
s
Absolute density of
incinerator salt
ρ
2,000
1,033
180
0.5
s
Density of asphalt binder
ρ
b
h owever, volum e decreased m arkedly from th e in itial
waste volum e. Th us, for exam ple, a test specim en con -
tain in g 20% bin der dem on strated a decrease in volum e
to 47% of th e in itial salt volum e, wh ich would practically
im ply a m ore th an doubled lan dfill service life. Th e fol-
lowin g m odel was proposed to explain th is volum e de-
crease: Wh ile 1 m 3 of in cin erator salt h as a m ass of 476 kg
(see Table 2), salt itself occupies volum e
(1)
For th e sake of sim plicity, let us assum e th at all salt
gran ules are th e sam e size, h ave a sph erical sh ape, an d
are arran ged with in th e stabilized waste specim en , as de-
picted in Figure 5.
As is obvious in the figure, each salt granule, includ-
in g free space between gran ules, would occupy th e
As th e above-m en tion ed m easurem en ts in dicate, salt
stabilization with an asph alt bin der supplem en ted by an
asph alt coat is h igh ly efficien t, th an ks to reduced pH,
con ductivity, an d an ion con cen tration s in leach ate from
all test specim en s. Th e fact th at th is decrease was virtu-
ally independent of stabilized waste binder content proves
th at asph alt coatin g on stabilized waste specim en form s
an im perm eable barrier to ion s. Moreover, stabilized waste
produced in practice would ordin arily h ave a sm aller spe-
cific surface area an d m ay even be verifiably expected to
h ave a con siderably sm aller leach ability.
In flu en ce of St a b iliza t ion on Wa st e Volu m e
Waste volum e is an im portan t factor in th e econ om ic as-
pect of lan dfill disposal. Lan dfill con struction is im -
m en sely costly, an d th us efficien t utilization of lan dfill
volum e capacity brin gs great fin an cial savin gs. Th erefore,
a volum e assessm en t of th e stabilization procedure em -
ployed h ere was carried out. Th e apparen t an d absolute
den sities of salt were m easured, as well as th e den sity of
asph alt bin der. Th e m easured values are sum m arized in
Table 2.
sp ace b et ween salt
salt gran ules
gran ules filled en tirely
or partially by asph alt
bin der
Th e total waste volum e m igh t be expected to in crease
th rough stabilization , owin g to th e volum e of added
bin der. In th e stabilizin g procedure used in th is work,
Figure 5. Model of salt granule arrangement in a compact stabilized
waste specimen.
456 Journal of the Air & Waste Management Association
Volume 50 March 2000

Vondruska et al.
volum e of a cube with its edge equal to the granule diam -
eter (as is well known, there is a possibility of closer ar-
ran gem en t of iden tical sph eres in space, a so-called
hexagonal close-packed structure, but this does not concern
us here). The real volume of salt granules would then be
volum e. Sin ce th is body would n ot con tain an y oth er free
space, its volum e sh ould be equal to th e sum of real salt
volum e an d added bin der volum e. In order to form a body
con tain in g, for in stan ce, 50% bin der, 1 m 3 of salt would
h ave to receive an added quan tity
(2)
kg of bin der
(10)
an d th e total volum e in cludin g free space between gran -
ules would be
Th e volum e of added bin der would be
Vt = N d3
(3)
(11)
wh ere N is th e n um ber of salt gran ules in th e sam ple an d
d is th e diam eter of salt gran ules. Th e total volum e of th e
sam ple would th en be
an d total volum e of th e body sh ould, th erefore, be Vt
= Vs + Vb = 0.238 + 0.461 = 0.699 m 3. Th e relative volum e
of th is body to in itial salt volum e (1 m 3) would be 69.9%.
Figure 6 com pares relative volum e values m easured on
prepared stabilized waste test specim ens with values calcu-
lated according to the presented m odel. As shown in the
figure, the m easured values of relative volum e actually dis-
play a break at about 32% and these values are nearly the
sam e with all test specim ens at lower binder content. Keep-
ing in m ind experim ental error (e.g., standard deviation in
m easured salt densities, as shown in Table 2), it is also evi-
dent that m easured and calculated values of relative vol-
um e are practically identical. This successfully explains the
very favorable reduction of waste volum e during stabiliza-
tion by m eans of the asphalt binder.
0.238 = 0.455 m 3
(4)
an d th e volum e of th e sam ple related to th e in itial salt
volum e would th en be 45.5%. Th e volum e of space be-
tween gran ules in th is body would be
Vf = Vt – Vs = 0.455 – 0.238 = 0.217 m 3
(5)
Th us, in order to form a stabilized waste sam ple con -
tain in g 20% bin der (wh ere w = bin der con ten t in stabi-
lized waste, %), 1 m 3 of salt would h ave to receive
119 kg of bin der
(6)
CONCLUSIONS
A laboratory procedure was developed an d tested for sta-
bilizin g salt from a solid waste in cin erator. It con sisted of
(1) m ixin g salt in to a m olten asph alt bin der, (2) com pact-
in g test specim en s from th e produced m ixture, an d (3)
th e subsequen t form ation of an asph alt coatin g on th e
surface of th ese specim en s.
Th e volum e of addition al bin der would be, th erefore,
(7)
Here, it is obvious th at bin der would fill in on ly part
of the free space between granules. If all intergranular space
were to be filled in, the necessary quantity would be
Measured values
mb = 0.217 × 1,033 = 224 kg
(8)
Values calculated on th e assum ption th at salt
particles are sph ere-sh aped - see exam ple in text
Bin der con ten t in th is body would th en be
(9)
All bodies con tain in g less th an 32% bin der sh ould,
th erefore, h ave a relative volum e of 45.5% of in itial salt
volum e un der th e above-m en tion ed assum ption s. In bod-
ies containing m ore than 32% binder, the volum e of added
bin der would be greater th an in tergran ular free space be-
tween salt gran ules in com pact order, so th is excess bin der
quan tity would cause an in crease in stabilized waste body
Bin der con ten t in stabilized waste [%]
Figure 6. Dependence of relative volume of stabilized waste test
specimens on binder content.
Volume 50 March 2000
Journal of the Air & Waste Management Association 457

Vondruska et al.
Th e obtain ed values of con ductivity, pH, an d an ion
con ten t in test specim en leach ates were quite satisfactory
an d alm ost in depen den t of th e bin der con ten t in stabi-
lized waste. From th e results, it is obvious th at stabiliza-
tion with an asph alt bin der an d supplem en tary form ation
of asph alt coatin g can be regarded as a com plete disposal
of waste. From Figures 2, 3, an d 4 it con vin cin gly follows
th at form ation of an asph alt coatin g on test specim en s
allows execution of S/S with a m ere 10% asph alt bin der.
Th e quan tity of n ecessary bin der for producin g a superfi-
cial asph alt coat can be practically n egligible if stabiliza-
tion is perform ed on a tech n ological scale.3
presented here can be transferred to practice without prob-
lem . Furth er, it can open up possibilities for utilizin g
proven tech n ologies an d curren tly used m ach in ery to
solve a com plex waste disposal problem .
ACKNOW LEDGMENTS
Fin an cial support for th is study was provided by th e Gran t
Agen cy of th e Czech Republic, No. 104/97/0127.
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Sass, B.M.; Wiles, C.C.; Mash n i, C.I. The Application of Solidification/
Stabilization to Waste Materials; Lewis Publishers: Boca Raton, FL, 1995;
pp 71, 133, 165-172.
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4. Zitsch er, F.F. “60 jah re erfah run gen m it asph altdich tun gen für
talsperen un d speich erbecken (60 years of usage of asph alt sealin g
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(in Germ an ).
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sealin g by m ean s of asph alt),” Bitumen 1995, 1(95), 14-16 (in Ger-
m an )
Mon itorin g th e volum e balan ce was a very im por-
tan t feature of stabilization procedure developm en t.
Durin g th e stabilization procedure, a waste volum e de-
crease to about 46% was observed. Th is very favorable
occurren ce was caused by th e great differen ce between
apparen t an d absolute den sities of in cin erator salt. To
explain th is volum e reduction , a m ath em atical m odel
was used, based on a sim plified con ception th at all salt
gran ules are th e sam e size, sph erical, an d arran ged in
com pact order in th e stabilized waste. Relative volum e
values of stabilized waste calculated on th e basis of th is
m odel an d actual relative volum e values m easured at
prepared test specim en s were in accord. Th is in dicated
th at th e m ath em atical m odel correspon ded relatively
accurately with reality.
6. Shell Bitum en. The Shell Bitumen Industrial Handbook; Design and Print
Partn ersh ip Ltd.: Guildford, Surrey, U.K., 1995.
7. Usm an i, A.M. Asphalt Science and Technology; Marcel Dekker, In c.: New
York, 1997; pp 119-134.
This study of salt stabilization from an industrial waste
in cin erator by m ean s of an asph alt bin der was con ducted
on a com pletely h om ogen ized salt sam ple from on e in -
cin erator. In th e future, it will be n ecessary to verify th is
stabilization m eth od with salts from various in cin erators
an d/or with sim ulated waste.
A lon g-term leach in g test h as been laun ch ed to as-
sess th e lon g-term stability of in cin erator salt stabilized
waste. Owin g to th e lon g duration of th is experim en t,
results h ave yet to be establish ed. Leach ate con ductivity
will be system atically m easured over approxim ately th ree
years, an d upon th e con clusion of th e test a m ath em ati-
cal an d statistical forecast of stabilized waste leach ability
will be projected. Th is test sh ould prove th at stabilization
of salt from a waste in cin erator by m ean s of an asph alt
bin der com bin ed with an asph alt coatin g provides com -
plete an d truly perm an en t waste disposal.
About the Authors
Milan Vondruska is an assistant professor at the Faculty of
Technology Zlín, Department of Environmental Technology
and Chemistry, Czech Republic. He deals with hazardous
solid waste disposal by means of solidification/stabilization
technologies. Vratislav Bednarik and Jiri Samsonek are
chemical engineers studying for Ph.D.s at the Faculty of
Technology, Zlín. Joseph Houser is an assistant professor
at the Faculty of Technology, Zlín in chemical analysis. All
authors may be contacted by e-mail: vondruska@zlin.vutbr.cz.
Applied asph alt tech n ology h as been in developm en t
for about 60 years.4 We feel th at th e laboratory study
458 Journal of the Air & Waste Management Association
Volume 50 March 2000