Determination of Color Removal and Fading Performance of Environmentally Friendly Chemical Alternatives to Hydrosulfite in Reactive Dyed Cotton Knitted Fabrics Depending on Dye Chromophore

ABSTRACT

As is known, color stripping can be done with oxidizing or reducing agents. Today, reactive dye stripping is conventionally carried out via reductive method using hydrosulfite. However, from an environmental point of view, the use of more ecological chemicals has gained importance. In this study, it is aimed to determine the performances of reducing and oxidizing chemical alternatives to hydrosulfite, depending on the reactive dye chromophore. On the other hand, it was also aimed to provide a color fading effect on reactive dyed cotton fabrics with a treatment applied after dyeing. For this purpose, color stripping and/or fading effect was investigated on cotton knitted fabrics dyed with four different reactive dyes having anthraquinone (Reactive Blue 19), phthalocyanine (Reactive Blue 21), monoazo (Reactive Red 239) and metal azo (Reactive Red 23) chromophores. Studies were carried out with hydrosulfite, sodium hydroxymethane sulfinate and potassium persulfate at five different concentrations. It can be said that sodium hydroxymethane sulfinate and potassium persulfate can be used as an alternative to hydrosulfite in red dyes and blue dyes, respectively. COD and BOD values of wastewater of potassium persulfate treatment was found to be lower than hydrosulfite, which indicates that it is an ecological alternative over hydrosulphite.

摘要

众所周知，脱色可以用氧化剂或还原剂进行. 如今，活性染料的脱色通常是通过使用亚硫酸氢钠的还原法进行的. 然而，从环境角度来看，使用更多的生态化学品已变得重要. 在这项研究中，根据活性染料生色团的不同，旨在确定还原和氧化化学替代品的性能. 另一方面，它还旨在为活性染色棉织物提供褪色效果，并在染色后进行处理. 为此，研究了4种不同活性染料 (蒽醌 (活性蓝19) 、酞菁 (活性兰21) 、单偶氮 (活性红239) 和金属偶氮 (反应红23) 生色团) 对棉针织物的退色和/或褪色效果. 对5种不同浓度的亚硫酸氢钠、羟甲烷亚硫酸钠和过硫酸钾进行了研究. 可以说，羟甲烷亚硫酸钠和过硫酸钾分别可用作红色染料和蓝色染料中连二亚硫酸钾的替代品. 研究发现，过硫酸钾处理废水的COD和BOD值低于亚硫酸氢钠，这表明它是一种生态替代品.

KEYWORDS:

• Reactive dye
• chromophore
• stripping
• vintage effect
• ecology
• cotton knitted fabric

关键词:

• 活性染料
• 生色团
• 剥离
• 复古效应
• 生态学
• 棉针织物

Highlights

• The use of sodium hydroxymethane sulfinate (HMS) and potassium persulfate (PPS) as an alternative to hydrosulfite in color stripping/fading process has been investigated first time in literature depending on the dye chromophore.

• It has been determined that HMS-based reducing chemicals or potassium persulfate, can be used as alternatives to hydrosulfite in color removal.

• At low concentrations of usage, a vintage effect could be obtained, while at high concentrations color of the fabric will be stripped.

• COD and BOD values of wastewater of PPS treatment was found to be lower than hydrosulphite.

Acknowledgements

We would like to thank Setaş company for kindly supplying dyes used in our experiments.

Disclosure statement

No potential conflict of interest was reported by the author(s).