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Turkish Journal of Fisheries and Aquatic Sciences 7: 97-103 (2007)
© Central Fisheries Research Institute (CFRI) Trabzon, Turkey and Japan International Cooperation Agency (JICA)
Pollutants of Textile Industry Wastewater and Assessment of its Discharge
Limits by Water Quality Standards
Introduction
The textile industry uses vegetable fibres such as
cotton, animal fibres such as wool and silk, and a
wide range of synthetic materials such as nylon,
polyester, and acrylics. The production of natural
fibres is approximately equal to the amount of
production of synthetic materials (of which polyester
accounts for about half) (Commission, 2002).
Because textile operations produce so much
wastewater, mills may be tempted to assume that they
cannot avoid large volumes of wastewater, and
therefore, they may become lax in pollution
prevention. In practice, mills vary considerably in the
amount of water and wastewater pollutants they
discharge. One essential and often difficult step in
water pollution prevention is to accurately and
realistically assess the current status of mill and its
potential for improvement. This assessment is
necessary to target specific waste streams that will
maximize pollution prevention. The first step in a
pollution prevention strategy for water is a thorough
audit and characterization of wastewater from textile
operations (Wood, 1992). Comparing the information
from this audit with benchmark data allows for
realistic goal-setting and economic projections for
water pollution reduction activities. Several options
exist for benchmarking an operation and, hence, for
identifying pollution prevention targets. Fibres used in
the textile industry can be divided into two main
categories: natural fibres (e.g. wool, hair, silk, cotton,
flax etc.) and synthetic fibres (e.g. rayon, nylon etc.)
(Sahin, 1996). Pollutants in wastewater from textile
factories vary greatly and depend on the chemicals
and treatment processes used. Pollutants that are
likely to be present include suspended solids,
biodegradable organic matter, toxic organic
compounds (e.g. phenols), and heavy metals (URL 1).
Many studies have been published on water
pollution from textile operations. Brown and Anliker
summarised the effects of textile effluent on the
environment and the toxicity with respect to fish and
other aquatic organisms, sewage bacteria and plants
(URL 2). For example, suspended solids can clog fish
gills, either killing them or reducing their growth rate.
Other important impact, they also reduce light
penetration. This reduces the ability of algae to
produce food and oxygen (URL 3).
The other parameter, sulphates (SO4=) can be
naturally occurring or as a result of municipal or
industrial discharges. Point sources include sewage
treatment plants and industrial discharges such as
tanneries, pulp mills and textile mills. Sulphates are
not considered toxic to plants or animals at normal
concentrations. In humans, small concentrations cause
a temporary laxative effect. However, doses of several
Abstract
Textile industry is one of the most important and rapidly developing industrial sectors in Türkiye. It has a high
importance in terms of its environmental impact, since it consumes considerably high amounts of processed water and
produces highly polluted discharge water in large amounts. Textile mills in Türkiye are required to control their discharge
and therefore have started installing treatment plants in the name of environmental protection.
The wastewater treatment plants of 11 textile mills in the woven fabric and knit fabric finishing industry were
investigated in this study. Performances of the treatment plants were evaluated by in situ inspections and analyses of influent
and effluent samples. The cost of the existing treatment plants is also evaluated.
For the treatment of textile industry wastewater, biological treatment, chemical treatment and combinations of these are
used. Plants utilizing biological treatment rather than chemical processes claim that their preference is due to less excess
sludge production, lower operational costs and better COD removal in biological treatment.
Waste water parameters in the effluent of biological treatment plants were in compliance with the ISKI (Istanbul Water
and Sewerage Administration) discharge standards.
However, if sodium sulphate in dyeing process and sulphuric acid in neutralization processes are used before a
biological treatment, sulphate in the effluent exceeds 1700 mg/l. This problem can be avoided by using HCl or CO2 rather
than H2SO4 in neutralization and NaCl instead of Na2SO4, if the use of Na2SO4 is not necessary.
Key words: Phytoplankton, estuarine, pollution, tide, floodwaters, creek.
Neşe Tüfekci1, Nüket Sivri1,*, İsmail Toroz2
1 Istanbul University, Faculty of Engineering, Department of Environmental Engineering, 34320, Avcılar, İstanbul, Türkiye.
2 Istanbul Technical University, Department of Environmental Engineering, 80626, Maslak, İstanbul, Türkiye.
* Corresponding Author: Tel.: +90 212 473 70 70 /17651; Fax: +90 212 473 71 80;
E-mail: sivrin@gmail.com
Received 03 July 2006
Accepted 18 June 2007
98 N. Tüfekçi et al. / Turk. J. Fish. Aquat. Sci. 7: 97-103 (2007)
thousand units cause all long-term illness effects.
Sulphates are toxic at very high concentrations.
Problems caused by sulphates are most frequently
related to their ability to form strong acids which
changes the pH. In this way, phosphates are not toxic
to humanbeings or animals unless they are present at
very high levels. Digestive problems could occur
from extremely high levels of phosphate (URL 1).
Textile industry in Türkiye is concentrated in
Istanbul where there exist 116 plants that are
specifically treating wastewaters of textile industry.
Seventeen of these treatment plants are biological, 83
are chemical, 14 are chemical and biological, and 2
are physical and chemical (Ucar, 1995).
The discharge standards for the textile industry
in Istanbul are set by Istanbul Water and Sewerage
Administration (ISKI), which also controls and
inspects the industrial wastewater discharges.
Industries are required to pretreat their wastewaters to
meet the standards set by ISKI, according to which
they are allowed to be discharge to the city sewer
system (ISKI, 1994).
In this study, 11 textile mills that have treatment
facility were chosen to investigate their material
production, use of processed water, wastewater
production, and treatment facility. The cost of
treatment from these plants is also investigated. The
products and processes of these 11 mills are
summarized in Table 1.
When these industries were selected, waste
water treatment plants that included different
treatment methods were considered. The chemical
and/or biological treatment methods used in the
treatment of textile industry wastewater were
characterized, problems in treatment plants were
explained and solutions were proposed.
Materials and Methods
The most important parameters in wastewater
from textile industry are COD (Chemical Oxygen
Demand), BOD5 (Biological Oxygen Demand), pH,
fats, oil, nitrogen, phosphorus, sulphate and SS
(suspended solids) (Tufekci et al., 1998). The influent
Table 1. Production and wastewater flow rates of the mills investigated
Mill Material Process Dyeing Wastewater Flow (m3/day)
A Cotton • Cotton Knitting
• Dyeing
• Washing
• Kasar
• 90% Reactive
• 10% Direct
Dyeing: 150
Washing: 90
Total: 240
B Cotton • Cotton Knitting
• Kasar
• Dyeing
• 90% Reactive
• 10% Direct
300
C Cotton • Weaving
• Jeans Dyeing
• Jeans Washing
Dyeing: 100
Washing: 240
Total: 340
D Cotton • Kasar
• Dyeing
• Washing
• Reactive 400
E Polyester
• Socks Knitting
• Dyeing
• Washing
20
F Cotton • Kasar
• Dyeing
• 85% Reactive
• 10% Direct
• 5% Pigment
300
G Cotton • Jeans Washing
• Cloth Making
250
H Cotton
Polyester
• Kasar
• Dyeing
• Cloth Printing
• 80% Reactive
• 10% Direct
• 10% Pigment
300
I Polyester
• Cord Production
• Cord Dyeing
• Dispersive 60
K Polyester
Wool
Acrylic
• Cord Production
• Dyeing
• 40% Acrylic
• 20% Polyester
• 40% Wool
95
L Cotton
Polyester
• Cord Production
• Mercerized
• Kasar
• Dyeing
• Reactive
• Direct
Polyester Dyeing:20
Cotton Dyeing:150
Total: 170
99 N. Tüfekçi et al. / Turk. J. Fish. Aquat. Sci. 7: 97-103 (2007)
Table 2. Measured influent and effluent values and removal efficiencies
Mill A B C D
Parameter Inf Eff. Rem. Inf Eff. Rem. Inf Eff. Rem. Inf Eff. Rem.
BOD5 (mg/l) 293 42 86 370 26 93 600 152 75 420 30.3 93
COD (mg/l) 614 120 80 714 92 87 1200 518 57 980 200 80
SS (mg/l) 56 22 60 120 9 92 300 96 68 300 32 89
TKN (mg/l) 10 7.4 26 10 8 20 30 15.2 49 20 11.3 43
TP (mg/l) 1.3 0.7 46 2 0.8 60 2 0.34 83 4 3.6 10
Grease (mg/l) 34 4 88 40 4 90 50 13 74 40 6.7 83
Mill E F G H
Parameter Inf Eff. Rem. Inf Eff. Rem. Inf Eff. Rem. Inf Eff. Rem.
BOD5 (mg/l) 1140 181 84 715 363 49 520 162 69 410 48 88
COD (mg/l) 1960 877 55 1130 780 31 1030 599 42 900 129 86
SS (mg/l) 653 247 62 420 109 74 670 431 36 230 10 95
TKN (mg/l) 60 49 18 43 27 37 37 17.6 52 19 14.6 23
TP (mg/l) 11 3 73 9 4 55 2,8 0.7 75 2.4 0.2 92
Grease (mg/l) 133 62 53 97 31 68 71 19.4 73 48 6 87
Mill I K L
Parameter Inf Eff. Rem. Inf Eff. Rem. Inf Eff. Rem.
BOD5 (mg/l) 974 186 81 615 242 61 280 112 60
COD (mg/l) 1740 636 63 1605 800 50 720 298 59
SS (mg/l) 600 77 87 470 288 39 180 33 82
TKN (mg/l) 11 1,8 84 92.5 53 43 17 9 47
TP (mg/l) 3 0,33 89 4 0.3 92 3 1 66
Grease (mg/l) 120 65 46 127 32 75 52 9.2 82
Inf.: Influent
Eff.: Effluent
Rem.: Removal Efficiency (%)
and effluent characteristics and efficiencies of
treatment plants of the mills, most of which are
cotton-fabric refining mills and polyester, wool,
acrylic, were investigated in this study. The effluents
values are average of at least 6 samples taken at
arbitrary times (Table 2). The effluent concentrations
of BOD5, COD, SS, TKN (Total Kjeldahl Nitrogen),
TP (Total Phosphor) and Grease were analyzed
according to Standard Methods (APHA, 1998).
Results
These analyses along with the discharge
standards set by ISKI and indicated in the Water
Pollution Control Regulation (SKKY) (ITKIB, 1995)
are also presented in Figure 1 to 8.
It is seen in Table 2 that all the parameters from
mill A are under the discharge limits, except for
BOD5 and sulphate. The results of analysis however
imply that the treatment plant is operated only when it
is inspected by the authorities. When the effluent
characteristics of mill B are examined closely, the
treatment efficiency is close to 90%. The fact that
effluent suspended solids (SS) and BOD5 values are
quite low implies that the sample might have taken
from the supernatant of the final sedimentation tank.
Despite some violations of the limits for BOD5 COD,
total sulphur and pH, it is seen that the treatment
facility of mill C was operated efficiently enough.
The treatment facility at mill D treats 300
m3/day industrial wastewater on top of 100 m3/day
municipal wastewater. It works with high efficiency.
However, the raw water characteristics of this
treatment plant are not above the discharge limits.
When the influent and effluent values are compared, it
seems that a two-stage treatment may not be
necessary for this mill. The analysis carried out at the
treatment plant of mill E shows that TKN, COD and
SS were above the discharge limits of ISKI at 50% of
all times. It is seen in Table 2 that the treatment plant
of mill F was one of the low efficiency facilities.
However, this did not pose a significant problem for
the firm, except for BOD5 and COD. Apart from SS,
there was not a single parameter that caused a
problem for mill G, which is a jeans-washing facility.
When the values given in Table 2 are compared
to the discharge limits, it is seen that the additional
activated carbon unit to the prefabricated chemical
treatment facility is not really necessary for this mill.
The effluent values of mill H is one of the lowest.
When the effluent analysis from mill K is examined,
it is seen that they have a chronic nitrogen problem.
The treatment efficiency for the other parameters is
not very satisfactory either. For this mill, where wool
100 N. Tüfekçi et al. / Turk. J. Fish. Aquat. Sci. 7: 97-103 (2007)
0
50
100
150
200
250
300
350
400
ABCDE F GH I K L
Firms
Discharge Values (mg/l)
Average Effluent BOD5
ISKI Limit
SKKY Limit
Figure 1. Average effluent BOD5 from the mills.
0
100
200
300
400
500
600
700
800
900
1000
ABCDE F GH I KL
Firms
Discharge Values (mg/l)
Average Effluent COD ISKI Limit SKKY Limit
Figure 2. Average effluent COD from the mills.
0
50
100
150
200
250
300
350
400
450
500
ABCDE F GH I K L
Firms
Discharge Values (mg/l)
Average Effluent SS
ISKI Limit
SKKY Limit
Figure 3. Average effluent SS from the mills.
0
10
20
30
40
50
60
ABCD E FGH I KL
Firms
Discharge Values (mg/l)
Average Effluent TKN
ISKI Limit
Figure 4. Average effluent TKN from the mills.
N. Tüfekçi et al. / Turk. J. Fish. Aquat. Sci. 7: 97-103 (2007) 101
0
0,5
1
1,5
2
2,5
3
3,5
4
4,5
ABCDE F GH I KL
Firms
Discharge Values (mg/l)
Average Effluent Total Sulfur
ISKI Limit
Figure 5. Average effluent total sulphur from the mills.
0
2
4
6
8
10
12
ABCDE F GH I KL
Firms
Discharge Values (mg/l)
Average Effluent Phenol
ISKI Limit
SKKY Limit
Figure 6. Average effluent phenol from the mills.
0
200
400
600
800
1000
1200
1400
1600
1800
ABCDE F GH I KL
Firms
Discharge Values (mg/l)
Average Effluent Sulfate
ISKI Limit
Figure 7. Average effluent sulphate from the mills.
0
2
4
6
8
10
12
ABCDE F GH I KL
Firms
Discharge Values (mg/l)
Average Effluent Total Phosphor
ISKI Limit
Figure 8. Average effluent phosphorus from the mills.
102 N. Tüfekçi et al. / Turk. J. Fish. Aquat. Sci. 7: 97-103 (2007)
dying with acrylic is also carried out, a combination
of chemical and biological treatment should produce
better results. The influent values of mill L, which
also have a mercerizing unit, are relatively low.
However, the treatment efficiency of this plant is
satisfactory.
Cost of Treatment
The cost of the treatment facilities of the textile
industries investigated in this study is given in Figure
9. The cost of the chemicals included in calculations
in Figure 9 is based on the unit prices as of April
2005.
The cost of electricity is based on the present
motor power of the facility and the assumption that
the treatment facility is operated 24 hours. The mills
that do not have maintenance cost declared that they
carry their maintenance on their own.
The yearly equivalence of the capital cost is
calculated by assuming a 10-year operational life and
20% yearly interest. The total cost per unit wastewater
for each mill includes the capital and operational
costs.
Discussion
It is observed in this study that 11 textile mills
that carry refining of knit and woven fabric have
mostly chemical treatment facilities. In addition, some
mills prefer biological or biological/chemical
treatment. Polyethylene (PE), FeSO4, Alum, Lime,
FeCl3 and several modifications of these chemicals
are used in chemical treatment facilities (Sahin, 1996;
Ucar, 1995). Because of the mandatory use of SO4=
based chemical in several process of textile industry,
high sulphate concentration in effluent is observed. It
will be beneficial to modify some processes in a way
that it would be possible to use less salt for dyeing, to
prefer chlorine instead of sulphate and to use HCl or
CO2 for neutralization. When the effluent values and
discharge standards by national authority are
compared, the parameters other than BOD5, COD and
SS do not require high degree of treatment. If it was
desired to discharge the effluent to receiving
environments rather than to the sewer system,
additional treatment units would require SKKY would
in order to meet their standards. It is possible that
advanced treatment technologies might be used to
treat the wastewater from these industries to a quality
that could allow reuse of wastewater. By this way, the
reduction in the use of processed water along with the
less costly treatment through reuse might contribute to
the faster amortization. It is a priority to consider the
advanced treatment technologies along with the
source reduction of waste rather than limiting the
treatment to single-stage. Like in the European
countries, many firms in textile industry are
concentrated on the use of environmentally friendly
chemicals and processes that use less water (Barclay
and Buckley, 2000). It is imperative for us to carry out
similar studies and to keep up with the technological
developments.
In addition, it is necessary to have educated
operators to run the treatment facilities. ISKI and
similar authorities should provide more strict
mechanisms of control based on the scientific
methods. Moreover, the firms that need to pay the
maximum attention to prevent pollution should be
encouraged by the local and central authorities. As
explained above, if more economical local treatment
facilities are opened, firms which do not require high
degree of treatment can control the pollution more
easily. And these firms should pretreat pH, SS and
temperature before they discharge them into the local
treatment plants. This is a much better approach than
having unfunctional or unoperating treatment
facilities. Between 1986 and 1989, ISKI and mostly
textile industry firms, wastewater of which is
conventional, signed a contract that required these
firms to pay their share in capital and operational cost
of treatment. The purpose was to build a central
treatment facility with this money that would treat
both municipal and industrial wastewater. However,
later on this plan was cancelled and each firm was
required to have its own treatment facility. However,
0,0
0,5
1,0
1,5
2,0
2,5
3,0
LA I CKFDB
Firms
Cost of Treatment ($/m3)
Figure 9. The cost treatment for the ınvestigated facilities.
N. Tüfekçi et al. / Turk. J. Fish. Aquat. Sci. 7: 97-103 (2007) 103
it is becoming harder in Istanbul to inspect whether
these facilities are operated properly. The effluent
phosphor, sulphate, and phenol values are below the
limits set by ISKI and it makes it necessary not to use
such parameters for control. The cost of effluent
analysis at ISKI laboratories will be reduced by these
means.
Conclusion
Certain pollutants in textile wastewater are more
important to target for pollution prevention than
others. For example, most dyeing machines have lint
filters and other primary control measures to keep lint
out of heat exchangers and off of the cloth; therefore,
total suspended solids (TSS) levels are low in raw
textile dyeing wastewater compared to many other
industries. On the other hand, biological oxygen
demand (BOD) and chemical oxygen demand (COD)
are relatively high in slashing, fabric formation, and
wet processing and therefore, are more important
pollution prevention targets. The aquatic toxicity of
textile industry wastewater varies considerably among
production facilities. Data are available showing that
some facilities have fairly high aquatic toxicity, while
others show little or no toxicity. If the discharge of
these facilities is assessed according to EC criteria,
additional treatment units would be required to meet
the standards. Despite the fact that it is not a common
practice in our country, the advanced treatment
technologies might be used to treat the wastewater
from these industries to such an extent of a quality
that could allow reuse of wastewater. By these means,
the reduction in the use of processed water along with
less costly treatment through reuse might contribute to
fast amortization. In addition, it is necessary to have
educated operators to run the treatment facilities.
Local and other authorities should provide more strict
regulations and directives like the EC (EPA, 1996).
References
American Public Health Association (APHA-AWWA-
WPCH). 1998. Standard Methods for the Examination
of Water and Waste Water. 20th ed. APHA
Washington D.C., 1270 pp.
Barclay, S. and Buckley, C. 2000. Waste Minimisation
Guide for the Textile Industry, A Step Towards
Cleaner Production (Volume 1), by The Pollution
Research Group University of Natal Durban South
Africa, The South African Water Research Com.,
January, 92 pp.
Commission Decision. 2002. The European eco-label for
textile products, 2002/371/EC of 15 May 2002, O.J. n
L 133 of 18.5.2002, Criteria valid until 31 May 2007,
Previous criteria valid until 31 May 2003,
(http://europa.eu.int/ecolabel).
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Discharges for Industrial Wastewaters, The Official
State Bulletin, No: 18340. Istanbul.
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and Legislation Department, Istanbul, 16 pp.
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URL 1. http://water.nr.state.ky.us/ww/waterres.htm
URL 2. http://www.tve.org/ho/doc.cfm?aid=1634&lang
=English
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