Short Comment on the Current Understanding of Ecological Behavior of Metal Azo Dyes and the Case for Proactive Wastewater Treatment

The relative non-toxic metal azo dyes present in wastewaters may be transported to long-distances where the metallic ion and the azo ligand may separate and manifest their own ecotoxicities. The environmental factors which can affect this may be too complex to monitor, and the case of on-site treatment at dye manufacturing or textile facilities is developed in this narrative. A simple mono-azo dye, namely, Eriochrome Black T, is introduced to illustrate molecular structures of metal azo dyes and possible candidate for ad hoc, preliminary testing of future treatment methods.