Decolorization of textile wastewater by gamma irradiation and its reuse in dyeing process

This paper describes the scope of employing high-energy gamma irradiation for textile wastewater treatment and the possibility of using the treated wastewater in the dyeing of knitted cotton fabric. The treatment was carried out in Cobalt-60 gamma radiation source at different irradiation doses (3, 5, 8, and 12 kGy). Then, the irradiated wastewater was used for dyeing of cotton fabric with reactive dye. The performance of the fabric dyed with treated wastewater was compared to that of the fabric dyed with freshwater. Hence, the dyeing performance was evaluated by comparing the depth of shades of both types of dyed fabrics from the analysis of absorption spectrum (K/S value vs. wavelength). The absorption curves of irradiated wastewater dyed fabric in light, medium, and dark shade of three different colors have shown close match to their corresponding freshwater dyed fabric. Variation of shade between the dyed fabrics, representing by ∆E values, were also found within the maximum acceptable limit as it ranges from 0.02 to 0.9. The color fastness of the dyed fabric was also measured with respect to perspiration, rubbing, and washing. In case of fastness, both types of fabrics have shown similar rating (4-5) which lies between "good" to "excellent"