Abstract:
BACKGROUND: This study investigated the water and pollution footprints of a dye house, which processed cotton knits,
polyester (PES) knits and PES-viscose woven fabrics. Experimental evaluation was carried out for each processing sequence.
Variations in wastewater flow and quality were established as a function of the production program in the plant. A model
evaluation of wastewater dynamics was performed and defined specifications of an appropriate treatment scheme.
RESULTS: The plant was operated with a capacity of 4300 t year−1 of fabric, which generated a wastewater flow of
403 500m3 year−1 and a COD load of 675 t year−1. The overall wastewater footprint of the plant was computed as 91m3 t−1 and
the COD footprint as 160 kg t−1 of fabric. Depending on the fabric type, results indicated expected changes in wastewater flow
between 600 and 1750m3 day−1 in COD load between 1470 and 2260 kg day−1 and in COD concentration between 1290 and
3400mgL−1.
CONCLUSION: A model simulation structured upon COD fractionation and related process kinetics revealed partial removal
of slowly biodegradable COD, coupled with high residual COD, which would by-pass treatment. Resulting biodegradation
characteristics necessitated an extended aeration system, which could also enable partial breakdown of residual COD. Effluent
COD could be reduced to 220–320mgL−1 with this wastewater management strategy.
© 2018 Society of Chemical Industry
