United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
Research and Development
EPA-600/S2-83-068 Nov. 1983
&EPA Project Summary
An Investigation of Selected Dye
Carriers Used in Commercial
Dyeing of Hydrophobic Fibers
Kwan-nan Yeh and B.F. Smith
This project was initiated to investi-
gate potential toxicities of dyebath
discharges from atmospheric dyeing of
100% polyester fabric with three
commercial dye carriers: trichloroben-
zene (TCB), biphenyl (BP), and o-phenyl
phenol (OPP). First, criteria were
established to rank the priority of all
commercial dye carriers, based on
known toxicities, volumes of consump-
tion, etc. Commercial dyeing of polyester
fiber/fabric was simulated in the
laboratory, using a commercial disperse
dye, other dyebath additives, and the
selected dye carriers.
Biological testing and chemical an-
alyses were carried out on the discharges
of these dyebath systems. Bioassays
included 1) Ames Salmonella/microsome
mutagenesis assay, 2) acute in-vivo
mouse quanta! assay and, 3) aquatic
ecological assay with Daphnia magna.
Analytical procedures were established
for both qualitative identification and
quantitative determination of key dye-
bath components.
In-depth studies were also carried out
on two dyebath systems (TCB and BP) to
identify species responsible for the
observed toxicity and to delineate
possible chemical and/or biological
interactions between the dyebath
components.
The TCB system was also investigated
to demonstrate that the toxicity of
these dyebath discharges can be reduced
significantly by increasing dyeing
efficiency. The dyeing process was
carefully evaluated to determine the
dye and carrier contents necessary to
achieve maximum dyebath efficiency.
This Project Summary was developed
by EPA's Industrial Environmental
Research Laboratory, Research Traingle
Park. NC, to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering
information at back).
Introduction
The Clean Water Act of 1977 identified
65 toxic compounds and classes of toxic
compounds which are subject to effluent
limitations and expanded the spectrum of
pollutant parameters to receive attention
in point source discharges to include
potentially toxic pollutants. Within these
65 compounds and classes, specific
elements or compounds have been
identified as priority pollutants. Included
in this priority list of 129 compounds are
13 metals, 114 organic compounds,
cyanide, and asbestos.
Wastewater guidelines for the textile
industry were developed in 1977, based
on studies sponsored jointly by EPA and
the industry. The water use and waste-
water discharge statistics for the textile
industry were reported in detail by
Sverdrup and Parcel and Associates, Inc.
in a study conducted for EPA. This study
indicates that the dyeing step in the
finishing of woven and knitted fabrics and
in carpet finishing is responsible for most
of the waste volume and contributes
substantially to the waste load in the
finishing process. Color is an obvious
adverse characteristic of the wastewater,
along with high levels of dissolved solids.
Carriers used in dyeing of polyester (and
other hydrophobic fibers) contribute
significantly to the biochemical oxygen
demand (BOD). Carriers which are used
to accelerate the dyeing of hydrophobic
fibers with disperse dyes (and sometimes
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other classes of dyes) are of particular
concern in the dyeing waste stream since
some of them appear as specific chemicals
on EPA's Priority Pollutant List.
The present study has focused on the
laboratory investigation of the toxicity of
major dye carriers currently used in the
commercial dyeing of polyester fiber/
fabric. The study includes development of
analytical techniques and systematic
biological evaluation, necessary to identify
and quantify toxic species in these
systems. The study was also intended to
provide information which can be used to
eliminate or to reduce toxic substances in
textile industry waste discharges.
The systematic approach taken to carry
out the above objectives included:
1. Establishing priority ranking of
current commercial dye carriers for
polyester fiber/fabric, based on
available data on current consump-
tion and toxicity of these chemicals.
2. Biological and chemical screening
of the three top-ranked carrier
systems, according to the order of
the priority established.
3. In-depth biological and chemical
studies of the first two toxic systems
identified in the above screening
studies, with the objectives of
identifying the species responsible
for the observed toxicity and deline-
ating possible interaction (synergistic
or antagonistic) between species.
4. Investigating means of eliminating
or reducing toxicity of these systems,
by varying dyebath contents, dyebath
conditions, and/or dyeing procedures.
Three commercial dye carriers, tri-
cholorobenzene (TCB), biphenyl (BP), and
o-phenyl phenol (OPP), were selected
based on the priority ranking established.
A commercial dye, disperse Yellow-23(Y-
23), and other dyebath additives were
used. A typical commercial atmospheric
dyeing process was simulated in the
laboratory to carry out all dyeing opera-
tions. Biological evaluations and chemical
analyses were carried out on the spentbath
liquor from each screening dyebath.
Bioassays included 1) Ames Salmonella/
microsome mutagenesis assay, 2) acute
in-vivo mouse quanta! assay and, 3)
aquatic ecological assay with Daphnia
magna.
Various analytical techniques were
used for qualitative and quantitative
analyses of key dyebath components in
the spentbaths and on dyed fabrics. An
analytical procedure using a computer-
assisted infrared (IR) spectrophotometer
was established for qualitative identification
of key dyebath components. Analytical
procedures employing a high-performance
liquid chromatography (HPLC) and an
ultraviolet/visible spectrophotometer
(UV/VIS) were also established for
quantitative analyses of carriers and dye.
In-depth studies of two carrier systems
(TCB and BP) were carried out to identify
the dyebath component(s) responsible for
the observed toxicities. The potential of
reducing the toxicity of these dyebath
systems by varying dyeing conditions and
initial dyebath compositions was also
investigated.
Conclusions
Toxicity screening of spentbath samples
from laboratory-simulated atmospheric
dyeing of 100% polyester fabric with a
commercial disperse dye (Yellow-23) and
commercial dye carriers (TCB, BP, and
OPP) indicated that all three carrier
systems are extremely toxic to Daphnia
magna assay. Median effective concen-
trations, ECso, for the 48-hr test were
25.5, 9.28, and 0.91 %, respectively, for the
TCB, BP and OPP carrier systems.
However, results of Ames Salmonella/
microsome mutagenesis assay and acute
in-vivo mouse quanta! assay were
negative for all three carrier systems.
Results of both bioassays and analyzed
concentrations of dye and carriers for all
three systems screened are shown in
Table 1.
In-depth studies, carried out on the TCB
and BP carrier systems, showed that
toxicity in these two systems was due
mainly to the dye (Yellow 23) and the
Table 1. Summary of Screening Studies
carrier (TCB or BP); no other dyebath
additives were found to have any signifi- (
cant toxicity. Furthermore, the toxicity
observed in these systems was found to
be the additive effect of the dye and the
carrier. The OPP system (the most toxic to
Daphnia magna) was not studied in depth
because of project budgetary constraints.
A material balance made around the
dyeing process showed that, in all three
systems (TCB, BP, and OPP), a significant
amount (more than 50%) of the original
carrier content in the dyebath was lost,
through volatilization, during dyeing. This
may have an adverse impact on the air
environment.
Studies varying dyeing time and
original carrier content indicate that
dyeing conditions can be optimized to
minimize the amount of residual dye and
carrier in the wastewater. This is one
potential technique for reducing the
toxicity of these wastewaters.
The present study has developed and
established a basis for analytical tech-
niques which can be applied to relatively
simple textile waste systems, such as
dyebath discharges. It has also demon-
strated that the systematic approach of
biological and chemical screening and in-
depth investigation effectively identifies
toxic species and evaluates overall
toxicity of these systems. However, A
successful applications of the techniques "
and the approach to a more complex
textile waste discharge remains to be
demonstrated.
Spentbath Contents:
Dye (Yellow-23), mg/l
Carrier, mg/l
Bioassay Results:
Ames (w/ and w/o liver
microsomal enzyme)
Mouse Quanta/ Assay
Daphnia magna Assay
24 hr "
48 hr"
TCB System
5.32
63.0(1,2,4, TCB)
Negative
Nontoxic
31.2(24.3-38.1)
25.5(19.2-32.7)
BP System
5.34
41.9(BP)
Negative
Nontoxic
20.45(8.16-51.25)
9.28(7.74-10.83)
OPP System
2.98
a
Negative
Nontoxic
0.91(0.70-1.12)
0.91(0.65-1.18)
"Not analyzed.
^Values in parentheses are 95% confidence intervals.
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K wan-nan Yeh and B. F. Smith are with the University of Maryland, College Park.
MD 20742.
Robert C. Hendriks is the EPA Project Officer (see below).
The complete report, entitled "An Investigation of Selected Dye Carriers Used in
Commercial Dyeing of Hydrophobic Fibers," (Order No. PB 83-247 569; Cost:
$13.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
GOVERNMENT PRINTING OFFICE 1983-659-017/7218
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