Textile Inking Waste Treatment Using Peroxide-Based Photooxidation

Abstract

The objective of this paper is to study the use of I Oz and UV to remove Terasil Blue, with view to process design. Terasil Blue is an Antraquinone-type colorant, with the C=O as the colouring group. Experiments were carried out in a photochemical quartz reactor, using a 150W mercury lamp as a UV source. Microdispersed Terasil Blue solutions, with initial concentration in the range 50-200 (mg/dnf), were treated with hydrogen peroxide (68-3420 (mM), in the presence of UV light, at 40°C, for around 40 min Experiments show that neither %(% nor UV light had any effect on Terasil Blue, when these are used on their own. However, joint HfeCVUV treatment effectively decomposes this organic compound, reaching final reductions in colour of up to 98%. Colorant decomposition by HaĈ /UV seems to follow three stages. An initial step where hydroxyl ions are formed and UV light is absorbed by ketone groups. This is followed by rapid and steady colorant decomposition until peroxide concentration reaches very low levels. The final stage shows a drastic slowing down of colour reduction, which coincides with the disappearance of hydroxyl ions. The final colour reduction is a function of the initial t Oz concentration. Even low t Oz concentrations lead to substantial reductions in colour. However, very high initial peroxide concentrations may not be appropriate since self decomposition is also favoured. Indeed, the rate of Oz is a linear function of its initial concentration and is not affected by the organic compound concentration. Transactions on Ecology and the Environment vol 32, © 1998 WIT Press, www.witpress.com, ISSN 1743-3541