A recent study conducted by researchers from the Philippine Textile Research Institute (PTRI) and BS chemistry students from the Polytechnic University of the Philippines (PUP) reveals a simple yet efficient method of breaking down toxic chemicals from dye effluents.  These wastes from textile mills contain a wide range of contaminants and are considered one of the largest groups of compounds that poase a grave threat to the environment if not properly treated and released to the environment. 

The study delved in the photocatalytic degradation of a reactive dye commonly used for dyeing cellulosic fibers, specifically the aqueous reactive violet 5, thru photocatalytic degradation using bulk Zinc Oxide (ZnO) slurry.  Zinc oxide is known as an important semiconducted with a wide variety of uses including that of photocatalysis.  It was used in this study for its relatively lower cost compared to other known photocatalysts.  Photocatalysis is one of the most recently explored processes of degrading dye effluents as it is considered as a more efficient way of removing toxic wastes and removing colors from wastewaters.

Results of the study showed degradation of organic solutions present in the wastewater and its decolorization from violet to colorless.  Through the felp of ultraviolet irradiation, dye degradation of waste waters with low dye concentration was enhanced immediately by 90% after being exposed for 30 minutes.  Further, ZnO concentration at 3,840 parts per million (ppm) is proven to degrade 400 ppm dye by 74% after 30 minutes of irradiation and nearly 100% after 90 minuites at pH 7 and temperature of 30oC.  The study also analyzed the degrdation of aqueous Reactive Violet 5 dye in the presence of other factors including UV light and ZnO slurry as photocatalysts.  Further, the study reveals that pH levels, temperative, and lamp intensity also contributed to the rate of photodegradation.  Higher pH levels, temperative, and lamp intensity also contributed to the rate of degrdation.  for use in upscale industrial textile wastewater treatments, the authors, Jeannie Lyn Cabansag and Julius Leaño of PTRI and PUP students Jesus Dumelod, John Cyrus Alfaro, John Arsenal, Jolivette Sambot, and Lorna Enerva, recommend further studies on identifyinf degradation products and corresponding toxicity. (Joy Camille A. Baldo, S&T Media Service)