Abstract:
|
The presence of aromatic amines in effluent from dyeing processes of the textile industry is an added
problem to the high coloration typical of this type of effluent. The main objective of the present work was to
eliminate these two problems simultaneously by electrochemical treatment using bath solutions containing
three azo dyes. For the analysis of amines, a liquid–liquid extraction method was developed as an easier and
faster alternative to the method described in the standards and widely used in analytical laboratories. Four
amines (aniline, o-toluidine, 4-chloroaniline and 4-aminobiphenyl) were detected by GC-MS in the residual
azo dye baths. A total amine concentration of between 2.5 and 1 ppm was detected, 4-aminobiphenyl being
the main compound. Both residual colour and amines were removed by electrochemical treatment carried
out at three current densities (3, 24 and 40 mA/cm2). At 24 mA/cm2, more than 90% of colour removal was
achieved, and the total amine concentration was reduced to below 0.15 ppm. |