Dye-free wastewater dyeing method in yarn-dyed field

The invention belongs to the technical field of textile dyeing and finishing, and particularly relates to a dye-free wastewater dyeing method in the yarn-dyed field. According to the dye-free wastewater dyeing method in the yarn-dyed field, dye and anhydrous sodium sulphate are not added into wastewater obtained after reactive dyeing in the yarn-dyed field, yarn is directly dyed, and the dye concentration in the wastewater obtained after reactive dyeing in the yarn-dyed field is larger than or equal to 3% o.w.f, and therefore, the dye and the anhydrous sodium sulphate are not needed to be added, light-color yarn with low color requirements is dyed by directly adopting dark-color dyeing wastewater, and the method is a huge progress in the field; and the method in which no dye is added and the dyeing wastewater is directly used for dyeing is of great significance. 本发明属于纺织品染整技术领域，具体涉及一种色织领域无染料添加的废水染色方法。本发明所述的色织领域无染料添加的废水染色方法，是将色织领域活性染色后的废水不添加染料和元明粉，对纱线直接进行染色，色织领域活性染色后的废水中的染料浓度大于等于3％o.w.f。因此，本发明无需添加染料和元明粉，直接采用深色染