General information about the sector
The textile industry is probably one of the most complicated industrial branch chain of the manufacturing industry. This sector is characterized by fragmentation and heterogeneity and is dominated mainly by Small and Medium Enterprises (SMEs). Clothing, home furnishing and industrial use are the predominant end-users of textile products. Textile industry’s activities are distributed all over EU, but only in a few EU states textile industries are concentrated. In textile industry, the leading producers are Italy, France, the United Kingdom, Germany and Spain. These countries together account for about three quarters of EU production. (According to EC, Textiles, Fashion and Creative Industries, Textiles and clothing in the EU).
Industrial Activities (NACE Codes C13.3 and 13.9)
Section |
Division |
Group |
Description |
C |
|
|
Manufacture |
|
C10 |
|
Manufacture of textiles |
|
|
C13.13 |
Finishing of textiles |
|
|
C13.9 |
Manufacture of other textiles |
Brine effluent in textile process
Textile processing includes many different steps in most of which wastewater is generated. Dyeing process is the one generating wastewater with significant presence of salts. The wastewater resulting from bleaching process seems to also contain salts.
Bleaching process aims at increasing the whiteness of cotton and other fibres by removing the natural yellowish coloring. The bleaching process is typically necessary if the finished fabric is to be white or dyed a light color. Some salts can be used in large amounts in bleaching process and consequently it is expected to be found in higher concentrations in the wastewater generated. The following table summarizes the parameters to consider for the brine wastewater characterization generated from bleaching process.
Key parameters for brine from bleaching process (in textile industries) wastewater characterization
Pollutants |
Parameters |
ClO- |
BOD |
ClO2- |
pH |
O22- |
EC |
Cl- |
DS |
PO43- |
SS |
Na+ |
|
F- |
|
SiO32- |
|
During dyeing process the textile material is given the desired color according to its final use. The predominant pollution problem of dyeing process is the color. Color, as mentioned also before, can cause several problems in water as it decreases its transparency combined with the fact that some of dyes and of their degradation products are toxic to aquatic organisms.
Typical pollutants generated in the dyeing step are colour and different auxiliary chemicals, such as organic acids, fixing agents, defoamers, oxidising/reducing agents, and diluents. A large amount of dyes ends up in wastewater in an unfixed state. Dyeing contributes most of the metals and almost all of the salts and color present in textile effluents. For some dyeing processes, about 75% of the salts ends up in the wastewater . The following table summarizes the parameters to consider for the brine wastewater characterization generated from dyeing process.
List of pollutants generated in dyeing process
Process/Fibres Dyeing |
Substances |
||
Inorganic |
Organic |
||
Cations |
Anions |
||
Cotton Viscose Linen |
Na+ |
Cl- |
-Naphthol (A), Acetate (B), Amides of naphtholic acid (B), Anionic surfactants (A), Cationic fixing agents (NB), Anionic dispersing agents (NB), Chloro amines (SB), formaldehyde (A), Formate (B), Nitro amines (SB), Non-anionic surfactants, residual dyes (NB), Soaps (A), Soluble oils (SB), Sulphated oils (A), tannic acid (A), tartrate (B), Urea (B) |
Cr3+ |
CO32- |
||
Cu2+ |
CO42- |
||
Sb3+ |
F- |
||
K+ |
NO2- |
||
NH4+ |
O22- |
||
|
S2- |
||
|
S2O32- |
||
|
SO32- |
||
|
SO42- |
||
Wool |
Na+ |
SO42- ,SO32- |
Acetate (B), dispersing agents (U), Formate (B), Lactate (B), residual dyes (NB), sulphonated oils (A), Tartrate (B) |
K+, NH4+ |
S2O4-, CO32- |
||
Cr3+, Cu2+ |
Cl- |
||
Al3+, Sb3+ |
|
||
Polyamide |
Na+ |
Cl- |
Acetate (B), Formate (B), Polyamide oligeines (U), residual dyes (NB), sulphonated oils (A) |
|
CO32- |
||
Acrylic |
Na+ |
SO42- |
Acetate (B), aromatic amines (A), formate (B), levelling agents (U), phenolic compounds (A), residual dyes (NB), retardants (U), surfactants, thioreia dioxide (A) |
Cu2+ |
|
||
NH4+ |
|
||
Polyester |
Na+ |
S4O62- |
Acetate (B), anionic surfactants (A), Antistatic agents (NB), dispersing agents (A), dye carriers (SB), EDTA (NB), Ethylene oxide condensates (U), formate (B), mineral oils (SB), non-ionic surfactants (A), residual dyes (NB), soaps (A), solvents (A) |
NH4+ |
ClO- |
||
|
NO3- |
||
|
Cl- |
||
|
SO32- |
Other parameters to consider in dyeing effluent process
Other parameters |
pH |
EC |
Color |
BOD |
TOC |
COD |