Conversion of waste to wealth by reusing rinse water in knit dyeing

A large quantity of water is used in the wet processing units of the textile sector in Bangladesh. As a result, a crisis in availability has been created in groundwater in different textile processing zones of the country, and it will be extended shortly, creating an alarming situation. For this reason, the reuse of wastewater is essential for water saving, leading to sustainable technology in textiles. In this work, rinse water obtained before the addition of fixing agent was reused to dye both cotton and polyester fabrics following the standard knit dyeing process. The same experiments were carried out using fresh water to compare dyeing performances between rinse water and fresh water. Acceptable results of fastness properties, color strength, and spectrophotometci evaluations were obtained in dyed fabrics using rinse water. For example, colorfastness to rubbing was 4-5 in the case of dyed 100% cotton fabric using rinse water. The corresponding value, which was obtained after dyeing with WTP water, was 3. K/S values were 3.419-5.397. As per spectrophotometric evaluations, CMC values were less than 1 in many cases. This method will be useful in dyeing units of Bangladesh and globally. A large quantity of wastewater will be saved, which would be remarkable in the textile industry.