Presence of Dioxins in Textile Dyes and Their Fate During the Dyeing Processes 

Boštjan Križanec,a* Alenka Majcen Le Marechal,a Ernest Vončina,b and Darinka Brodnjak-Vončinac 
a Faculty of Mechanical Engineering, University of Maribor, Smetanova 17, SI-2000 Maribor, Slovenia
b Environmental Protection Institute, Prvomajska ul. 1, SI-2000 Maribor, Slovenia
c Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova 17, SI-2000 Maribor, Slovenia

Considerable levels of highly toxic polychlorinated dibenzo-p-dioxins (PCCDs) and polychlorinated dibenzofurans (PCDFs) were determined in two among the six analysed disperse textile dyes. The dioxin homologue profile of these dyes was similar to that found in some environmental and industrial samples, connected with the textile industry. Dyes contaminated with dioxins were further used in industrial polyester dyeing processes at laboratory scale. We observed the changes in dioxin contents, dioxin transformations and their distribution during the textile dyeing process. After the dyeing and textile finishing processes the content of dioxins was up to fifteen times higher. More than 85% of the total dioxin content was found in dyed polyester. Other 15% was discharged with waste dye bath. Our results confirmed that the presence of dioxins in some textile dyes may be a significant source regarding human exposure and environmental contamination.

Key words: polychlorinated dibenzo-p-dioxins; polychlorinated dibenzofurans; textile dyes; formation