Decolorisation treatments of azo dye waste waters including dichlorotriazinyl reactive groups by using advanced oxidation method

Decolorisation treatments of azo dye waste waters, which include dichlorotr iazinyl reactive groups, were investigated by using ultraviolet (UV) radiat ion and hydrogen peroxide at various exposure times. Decolorisation time de creased when UV radiation power and hydrogen peroxide concentration increas ed. Colour removal reached 98.0-99.5% by using this method. Some environmen tal parameters of decolorised waste water, such as biological oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total ino rganic carbon (TIC), total carbon (TC), adsorbable organohalides (AOX), sul phate and chloride, were determined. It was concluded that TOC, COD and AOX decreased while BOD increased and sulphate ions remained unchanged. These results suggested that the dye molecules were totally destroyed and some of these decomposition products were removed as carbon dioxide and water to s ome degree.