Assessing the Effectiveness and Environmental Sustainability of Reactive Dyes for Their Structural Diversity

Abstract

This study aims to assess the environmental impact of different chemical classes of reactive dyes and their treatment. To attain this outcome, four different types of reactive dyes (Procion Blue PX-3R (Monochlorotriazine), Levafix Blue CA (Bi-functional heterogeneous), Remazol Brilliant Blue R (Vinylsulphone) and Remazol Brilliant Blue RR (Bi-functional homogeneous) on the cotton fabric were analyzed. The potential cytotoxic effect of different reactive dyes was evaluated using the growth inhibition test according to AATCC 22662 by exposing the culture over 72 hours at 21 °C. The dyeing operation was performed in a labrotex sample dyeing machine, and a data color spectrophotometer was administered to analyze the strength percentage of dyes in post-dye liquor. Among the reactive dyes, Levafix Blue CA exhibited better effluent characteristics compared to others, lowering the threat to the environment. The dyed wastewater was directly disposed of and treated in a pilot plant containing lime and ferrous sulfate as coagulant and polyacrylamide as polyelectrolyte, which resulted in a significant reduction of BOD5 (64.97-74.67%), COD (61.03-70.28%), TDS (55.02-61.97%) and TSS (47.07-50.19%) with improved pH and DO values. This investigation reflects the specific selection of a reactive dye leading to a lower environmental impact of a dyeing process coupled with wastewater treatment processes.