印染加工的四个工序都要排出废水，预处理阶段(包括烧毛、退浆、煮炼、漂白、丝光等工序)要排出退浆废水、煮炼废水、漂白废水和丝光废水，染色工序排出染色废水，印花工序排出印花废水和皂液废水，整理工序则排出整理废水。印染废水是以上各类废水的混合废水，或除漂白废水以外的综合废水。
Wastewater should be discharged from the four processes of printing and dyeing. In the pretreatment stage (including singeing, desizing, boiling, bleaching and mercerizing), desizing, boiling, bleaching and qinhuangd.37ix.com.cncangzhou.37ix.com.cn xiongan.37ix.com.cnshijiazh.37ix.com.cnbaoding.37ix.com.cnzhengding.37ix.com.cnmercerizing wastewater should be discharged. In the dyeing process, dyeing wastewater should be discharged. In the printing process, printing wastewater and soap liquid wastewater should be discharged. In the finishing process, finishing wastewater should be discharged. Printing and dyeing wastewater is a kind of mixed wastewater or comprehensive wastewater except bleaching wastewater.