Recycling indigo dye from waste water in textile industry

Recycling Indigo Dye From Waste Water in Textile Industry In this study, the wastewater that contains indigo dye from rope dyeing machines uses the method of reverse ozmosis system; a portion of water is treated, while the remaining portion was concentrated. And the resulting concentrated solution was used to dye the fabric. In this practice, washing water containing the indigo dye was used. Since the Indigo dye is a water-insoluble vat dye, it was used by reducing. In initial experiments, the dye which has been oxidized again naturally to obtain solid (powder) from the solution was investigated. Tests showed that this material was oxidized and become indigo dye without losing dye property. Resulting Indigo dye without losing property has been used with membrane systems to concentrate the solution, the fabric samples has been dyed with it, the waste water which was reduced, concentrated and containing indigo dye can be used to re-dye. Indigo dyeing wastewater from the washing tub of the machines has been gotten. The waste water which has less than 0.1 g/L of dye was passed through the membrane and was resulted in a concentrated solution. The concentrated solution has been passed through membrane for the second time to have more concentrated solution. This solution has been also used to dye the fabric and the color values have been checked. The waste water that was obtained from the solution which contains 3 g/L of indigo dye was passed through the membrane for the first time with the 12 bar of pressure was observed with 0,28 g/L of dye in it. Fabric has been dyed with this 0,28 g/L dye solution and reference color of the fabric was compared with new dyed fabric and result was darker blue with an increasing number of 18.6%. The solution was passed through for the second time and it was resulted with 0,34 g/L of dye in the solution. This solution which contains 0,34 g/L of dye has been used to dye a fabric and the fabric was compared with the reference fabric that has been dyed with 0,1 g/L of dye and the result was 26.5% darker blue. It has been observed in this study that the waste water which has been treated with the membrane system can also be used as a concentrated solution for dying.