基于间接电化学还原法对靛蓝染色过程环保性能的提升

针对当前靛蓝牛仔纱线传统染色过程还原剂用量多、污染大等问题,分别采用靛蓝/保险粉/烧碱和靛蓝/Fe(Ⅱ)-DGS-Abal B/烧碱体系对棉织物进行浸染染色。通过测定染液还原电位,染色残液COD、BOD,染色织物K/S值、耐摩擦色牢度和表面元素评价两种染色体系的染色效果和环保性能。结果表明,靛蓝/保险粉/烧碱体系中,当靛蓝与保险粉质量比为1.0∶1.6时,再增加保险粉用量,染色织物K/S值不再增加。采用响应曲面法设计靛蓝/Fe(Ⅱ)-DGS-Abal B/烧碱体系,在与靛蓝/保险粉/烧碱染色体系相同靛蓝用量、相同K/S值的情况下,优化后的媒介用量为:靛蓝2.5 g/L,烧碱25.0 g/L,硫酸亚铁5.1 g/L,葡萄糖酸钠3.9 g/L,Abal B 3.1 g/L。在此条件下,染色残液的COD、BOD分别降低了20.6%和20.3%。染色织物表面含铁量较少,颜色深度和耐摩擦色牢度与靛蓝/保险粉/烧碱染色体系基本相同。

Improvement of environmental protection performance of indigo dyeing process based on indirect electrochemical reduction

In view of the problems such as the large amount of reducing agent and pollution in the traditional dyeing process of indigo denim yarn, indigo/insurance powder/caustic soda and indigo/Fe(Ⅱ)-DGS-Abal B/caustic soda system were used respectively to dye cotton fabric. The dyeing effect and environmental protection performance of the two dyeing systems were evaluated by measuring the dyeing solution reduction potential, dyeing residue COD, BOD, K/S value, color fastness to rubbing and surface elements of the dyed fabrics. The results showed that the K/S value of dyed fabrics did not increase by increasing the dosage of insurance powder after the mass ratio of indigo and insurance powder reached 1.0∶1.6 in the indigo/insurance powder/caustic soda system. Response surface method was used to design the indigo/Fe(Ⅱ)-DGS-Abal B/caustic soda system. Under the condition of the same amount of indigo and the same K/S value as indigo/insurance powder/caustic soda dyeing system, the optimized amount of media were: indigo 2.5 g/L, caustic soda 25.0 g/L,ferrous sulfate 5.1 g/L, sodium gluconate 3.9 g/L, Abal B 3.1 g/L. Under these conditions, the COD and BOD of dyeing residue decreased by 20.6% and 20.3%, respectively. The dyed fabric surface contained less iron,the color depth and color fastness to rubbing were basically the same as that of indigo/insurance powder/caustic soda dyeing system.