Effects of Metal Ions Present in Recycled Water on Washing of Reactive Dyed Cotton Fabric

Abstract

Textile industry is a key source of contamination of heavy metal ions in water. These heavy metal ions include lead, cadmium, copper, arsenic, nickel, chromium, zinc, and mercury. These metals have been recognized as hazardous heavy metals because of their high degree of toxicity. Initially, copper was selected to determine the effects of metals present in recycled water during the washing process because of its extensive usage in the textile industry. However, copper becomes a part of process water while manufacturing and even a part of recycled water. Furthermore, recycled water contains such traces of metal that can cause problems during its reuse. In the current research, the presence of copper ions in water was simulated with copper sulphate and the obtained water was used for washing of fabric after reactive dyeing. The effects of salt on washing of three different types of reactive dyes, that is, monochlrotriazine, dichlorotriazine and vinylsulphone were evaluated by washing of dyed fabric. Moreover, evaluation process was achieved with different concentrations of salt at different temperatures, pH values, and time intervals. Besides, K/S, fixation%, color uniformity, color change, washing fastness, and rubbing fastness of samples were measured during evaluation. Results were also compared with detergent and water wash. Eventually, the results showed that copper has a prominent effect on fabric. Hence, it would be possible to allow certain concentrations of copper during the process of washing. Index Terms: cotton, exhaust dyeing, metal ions, reactive dye, recycled water