Sage Journals: Discover world-class research

Abstract

In this study, we used the new nanobubbles technology to create a green reactive washing process for the textile industry, as one of the most polluting sectors where environmentally friendly process designs are indispensable to protect the environment. With this technology, the possibility of eliminating the soaping-off step from the reactive washing sequence was investigated. For the design of an environmentally friendly reactive washing process, the effects of increasing the process temperature of the soaping-off step as well as the use of oxygen-enriched NBs in all washing steps after reactive dyeing with three different dyes were investigated. The results were evaluated by comparing the color coordinates, strength, and fastness of dyed cotton towels washed according to the conventional and alternative processes as well as examining the absorbance and chemical oxygen demand values of the washing baths. Alternative washings did not cause significant differences in color coordinates, while the lowest color strength and highest fastness values were obtained after washing with nanobubbles. The absorbance graphs showed that the most colorful baths belonged to the first bath of the nanobubble washing regime. Chemical oxygen demand measurements revealed that the alternative washing systems were more environmentally friendly than the conventional ones. Based on the results of this study, we concluded that it was possible to implement more eco-friendly washing methods by eliminating the use of soap.

Graphical abstract

Keywords

Sustainability Nanobubble Wastewater Reactive Soaping-off Absorbance

Introduction

The idea of in-depth investigation of the state of liquid and colloid systems at the nanoscale has taken a new place in the field of physicochemicals. After this new field was introduced by the bubble dissolution and growth theory in the 1950s, the existence of attractive forces between the hydrophobic surfaces of nanobubbles (NBs) was demonstrated in 1994. Since then, empirical studies have been carried out and NB generators have been commercialized rapidly.¹ NBs, tiny gas bubbles with a respective diameter of <200 nm², can form freely. Under the right conditions, NBs remain stable for long periods because of their high contact angle.^3,4 The use of NBs in different fields to increase the efficiency of gas–liquid phase processes has been studied by many researchers in recent years.⁵ NB applications have been accelerated in many sectors, including wastewater treatment,^6
–10 surface cleaning,^11
–14 agriculture,¹ the mining industry,¹⁵ oil recovery,^16,17 and medical applications.¹⁸ In the textile industry, e-Flow is a new technology based on NBs developed and patented by Jeanologia.¹⁹ With e-Flow, softening, enzyme flow and bleaching processes are performed with the use of a minimum amount of water.²⁰

Cotton, which constituted 24% of the world fiber production between 2018 and 2019, increased its percentage to 30% between 2019 and 2020.^21,22 The reasons for the preference for cotton, which has the largest production share among natural fibers,²³ are its high strength, softness, biodegradability, biocompatibility, hydrophilicity, breathability, and lack of static electricity.^24,25

Reactive dyes have become the most suitable dyes for dyeing cotton products due to their brilliancy, wide range of hues, excellent wet-fastness, ease of application, and low price.^25
–27 For the dyeing of the cotton product, electrolytes (30–100 g L⁻¹), such as sodium sulfate or sodium chloride, are used for the adsorption of the dye^28,29 according to the desired color strength, while alkali (pH 11) is used for the formation of covalent bonds between the fiber and the dye.^30,31 Meanwhile, the dyes remaining in the bath and not fixed on the fibers are hydrolyzed.³² That is why, to obtain good wet fastness after dyeing, a washing process consisting of several steps is carried out causing intense water consumption. These washing steps include one or more soaping-off stages depending on the color depths.^33
–35

From the sustainable and green production perspective, unfortunately, this class of dye is not environmentally friendly because of the discharge of alkaline wastewater, high concentrations of electrolytes, and unfixed/hydrolyzed dyes.^25,36,37 The reactive dyes, of which up to 40% can be hydrolyzed in the dyeing process, have high affinity for fiber through van der Waals, hydrogen bonding, and ion-dipole forces. For this reason, hydrolyzed dyes are removed by a multistep washing process after dyeing and high washing fastness, which is a characteristic of reactive dyeing, is obtained. The washing process, which includes various steps such as rinsing, washing, and soaping-off, and the treatment of wastewater produced by these processes, causes high water and energy consumption, and may constitute 50% of the total cost of reactive dyeing. Accordingly, indisputably one of the biggest problems in dyeing is water and energy consumption.^32,38
–40

In the literature, there are many articles on water saving,^41,42 reducing the use of chemicals,^43,44 treating wastewater with different methods and removing color in wastewater,^45
–47 etc., within the scope of environmental production in many areas of textile. However, there are hardly any studies on the use of nanobubbles, a new technology, in the development of environmentally friendly textile processes. For this purpose, the effect of NBs, as a new technology, in reactive washing and reducing the load of wastewater was investigated. In addition, the elimination of soap usage by the temperature increase method was investigated. The success of these two methods in developing an environmentally friendly washing process was analyzed by measuring the color coordinates, strength and fastness of dyed towel fabrics, and determining the absorbance and chemical oxygen demand (COD) values of the washing baths.

Experimental

Material

In this study, pre-treated 100% cotton towel (weight 370 g m⁻² produced from the warp and weft yarn count of Ne 20/2 and Ne 16/1, respectively) was used. Bifunctional reactive dyes Synozol Blue K-BR (CI. Reactive Blue 221) and Synozol Red K-HL (mixed) were supplied from EKSOY Chemicals. Another dye, monofunctional Itofix Turquoise Blue GN 266% (mixed), was supplied from Ilteks Dye and Chemicals. Sodium chloride (NaCl) and sodium carbonate (Na₂CO₃) were of technical grade. Acetic acid (80%) (CH₃COOH), technical quality, and Isopon HDS-T (Bozzetto Group) were used in the washing processes after reactive dyeing. Dyeing and washing processes were carried out by ATAÇ Lab-Dye HT. Water with nano-sized bubbles was obtained using the nanobubble generator provided by BST Water.

Method

The pre-treated cotton towel was dyed with reactive dyes in one depth (1%) by the exhaustion method. The towel was first treated with dye (1% o.w.f.), salt (30 g L⁻¹), and alkali (15 g L⁻¹) at 25°C for 10 min and later the dye bath temperature was raised to 60°C (at 1–2°C/min). Dyeing was conducted at this temperature for 60 min. The liquor ratio was 10:1 in wet treatments. All treatments were repeated three times. The diagram of the reactive dyeing is given in Figure 1.

Figure 1.

Time–temperature diagram of conventional reactive dyeing.

The reactive washing process consisted of six stages. After rinsing at medium temperature (50°C, 10 min), a second wash with acetic acid (50°C, 10 min) and soaping with 1 g L⁻¹ soap at 85°C for 10 min were performed. Two 10-min rinsings were run at 80°C and 70°C, respectively, before a final rinse at 50°C for 10 min.

Two methods have been developed as alternatives to conventional washing (C). In the increased temperature (T) method, unlike conventional washing, the temperature of the soaping-off step was 10°C higher. In the other method, the NBs method, the use of soap was eliminated by using nanobubbles in all steps of washing. Figure 2 shows the details of the washing processes.

Figure 2.

Time–temperature diagram of conventional and alternative washings.

Measurement

The L*, a*, b*, C*, and h0 values were measured using reflectance measurements (under D65 illuminant and 10 standard observers), with the Konica Minolta CM-3600D spectrophotometer. Equation (1) was used for color difference (CMC (2:1)) measurements.

Δ E_{CMC}^{*} = \sqrt{{(\frac{Δ L^{*}}{l S_{L}})}^{2} + {(\frac{Δ C^{*}}{c S_{C}})}^{2} + {(\frac{Δ H^{*}}{S_{H}})}^{2}}

(1)

In Equation (1), L and C were constants defined by the user and weight the importance of lightness and chroma relative to the hue of the measured color. S_L, S_C, and S_H are the main weighting factors for lightness, chroma, and hue.⁴⁸

The K/S values were calculated using the Kubelka–Munk equation. The color strength (K/S) formula is presented in Equation (2).

\frac{K}{S} = \frac{{(1 - R)}^{2}}{2 R}

(2)

In Equation (2), K/S is the ratio of light absorption (K) to the light scattering (S) through the sample. R is the decimal fraction of the reflectance of fabric, K is the absorption coefficient, and S is the scattering coefficient.⁴⁹

The fastness properties of reactive dyed samples were determined according to standard methods of EN ISO 105-C06/A1M (color fastness to domestic and commercial laundering) and EN ISO 105-X12:2002-12 (color fastness to rubbing).

A UV–VIS spectrophotometer (RayLeigh VIS723 G) was used to determine the absorbance values of the washing baths at 400–700 nm.

COD measurements of soaping-off baths were conducted using the photoLab S12 photometer and Merck Millipore COD cell test.

Results and Discussion

Color Coordinates

Color coordinates of towels dyed with three different colors and washed with different methods are given in Table 1.

Table 1.

Color coordinates of dyed cotton towels.

	L*	a*	b*	C*	h0
Red
C	50.66 ± 0.21	45.36 ± 0.20	–2.18 ± 0.21	45.41 ± 0.05	357.25 ± 0.09
T	52.04 ± 0.23	45.83 ± 0.29	–4.32 ± 0.28	46.03 ± 0.28	354.62 ± 0.25
NBs	53.14 ± 0.15	43.83 ± 0.26	–3.91 ± 0.17	44.01 ± 0.30	354.91 ± 0.27
Blue
C	46.16 ± 0.09	–3.72 ± 0.14	–24.50 ± 0.18	24.78 ± 0.23	261.37 ± 0.06
T	46.86 ± 0.27	–3.36 ± 0.17	–25.46 ± 0.05	25.68 ± 0.26	262.48 ± 0.23
NBs	48.13 ± 0.15	–3.32 ± 0.19	–24.53 ± 0.27	24.75 ± 0.17	262.30 ± 0.10
Turquoise
C	63.42 ± 0.10	–32.19 ± 0.16	–23.46 ± 0.09	39.84 ± 0.13	216.08 ± 0.07
T	63.71 ± 0.27	–31.90 ± 0.15	–22.40 ± 0.20	38.98 ± 0.11	215.08 ± 0.17
NBs	63.73 ± 0.09	–32.84 ± 0.30	–20.91 ± 0.11	38.94 ± 0.26	212.46 ± 0.11

The coordinates of the dyeing using red, blue, and turquoise dyes were similar within their color groups. However, there were also minor differences. In red dyeing, the colors obtained from C and T washings were redder than that from NBs, while the blueness of T was higher than the others. In the NBs washing following the turquoise dyeing, a less blue color was obtained compared to the others, and less green color was obtained with T. The differences in the a* and b* coordinates of the blue color were negligible. These differences between washes are also visible in Figure 4.

Color Strengths and Differences

Figure 3 shows the color strengths of dyed cotton towels. The color differences caused by the washings performed with different methods after the dyeing compared to the conventional washing are given in Table 2. The reflectance values used in the color strength calculation are 530 nm for red, 620 nm for blue, and 680 nm for turquoise. In Figure 4, images of fabrics subjected to dyeing and different washing processes are given.

Figure 3.

Color strengths of dyed and washed cotton towels.

Table 2.

Color difference values for different (C, T, NBs) washing methods.

Color	Methods	∆E
Red	T	0.85
	NBs	0.90
Blue	T	0.17
	NBs	0.53
Turquoise	T	0.82
	NBs	1.32

Figure 4.

Photographs of dyed and washed swatches.

Considering the color strengths on the basis of the color of the dye, it was observed that a higher color depth was obtained from turquoise compared to the other colors, even though an equal amount of dyestuff concentration was used in dyeings. Although the turquoise dye was monofunctional, it had higher tinctorial strength than the others, which was thought to be the reason for this situation.

The color strengths of cotton towels subjected to different washing processes after dyeing showed that the highest color depths were obtained after conventional washing. This situation was similar for dyeings conducted with three different colors, and the lowest depths were obtained after NBs washing. While conventional washing provided higher color depth compared to other methods, it resulted in lower washing fastness of approximately a 1/2 point compared to the others (Table 3). Despite the decreasing color depth with the NBs method, the increased fastnesses showed that water with nano-sized bubbles was more effective in removing the unfixed/hydrolyzed dyes on the fabric compared to the C and T methods. Especially in turquoise-dyed towels, a color difference value greater than 1 (∆E = 1.32) supported the idea that more dye was removed from the fabric surface with NBs (Table 2). On the other hand, NBs and T methods did not cause significant color difference (∆E < 1) in red- and blue-dyed fabrics compared to C. These cases about color differences were also supported by the photographs of swatches (Figure 4). It was seen that the color change was the greatest in turquoise and the least in blue after washing according to the NBs and T methods. Although these results show that NBs could be used instead of the conventional process, it was interpreted that it would require additional treatment and cost in terms of color loss and change.

Table 3.

Washing and rubbing fastness of dyed and washed cotton towels.

Color	Method	Washing fastness						Rubbing fastness
Color	Method	CA	CO	PA	PES	PAN	WO	Wet	Dry
Red	C	5	4	5	5	4/5	5	4/5	5
	T	5	4	5	5	5	5	4/5	5
	NBs	5	4/5	5	5	5	5	4/5	5
Blue	C	5	4/5	5	5	5	5	4/5	5
	T	5	4/5	5	5	5	5	4/5	5
	NBs	5	4/5	5	5	5	5	4/5	5
Turquoise	C	5	3/4	4/5	5	4/5	5	4	4/5
	T	5	4	5	5	4/5	5	4/5	5
	NBs	5	4	4/5	5	5	5	4/5	5

Washing and Rubbing Fastness

Washing and rubbing fastness values of dyed cotton towels are given in Table 3.

Since reactive dyes are used in dyeing, the cotton fabrics in the multifiber stained ½ and 1 point more than the other fibers. The turquoise dye, on the other hand, stained the cotton more than the others. This was explained by the different functionalities of the dyes, that is, the blue and red dyes were bi-functional, and the turquoise was monofunctional. While the NBs washing process increased the washing fastness of turquoise- and red-dyed fabrics by approximately half a point, this difference was not observed in blue dye. Moreover, this could be supported by the lowest color difference being in blue and the highest in turquoise, as given by Table 2. Increased fastness with NBs revealed that it was more effective than the others in removing hydrolyzed/unfixed dyes. When the rubbing fastnesses were examined, it was observed that the wet rubbing values were half a point lower than the dry ones, but all of them were at good and excellent levels. Considering the color strengths of fabric (Figure 3) and functionality of dyes, it was not a coincidence that the lowest fastness values were obtained from turquoise-dyed fabrics.

Absorbance

In Figure 5, the absorbance graphs of the first and third baths of the washings are given. Pictures of washing bath swatches are shown in Figure 6. The maximum absorbance values of the first and third washings are presented in Table 4. The graphs of the first and third baths are given because they have the highest absorbance values. In the graph, numbers of baths are shown with 1 and 3. The maximum absorbance for red and blue dye solutions was recorded at 510–520 and 605 nm, respectively. For turquoise, the average absorbance values corresponding to 615 and 660 nm wavelengths were used.

Figure 5.

Absorbance graphs of first and third baths of washing sequences: (a) red, (b) blue, (c) turquoise.

Figure 6.

Pictures of washing baths swatches.

Table 4.

Maximum absorbance values of first and third washing baths.

Color	Methods	First bath	Third bath
Red	C	0.43	0.43
	T	0.46	0.43
	NBs	0.58	0.52
Blue	C	0.31	0.15
	T	0.33	0.33
	NBs	0.92	0.23
Turquoise	C	1.56	0.65
	T	1.73	1.30
	NBs	2.13	0.20

Among the first washing baths, the highest absorbance values were obtained with NBs. This means that more hydrolyzed/unfixed dyes with NBs passed into the bath. The absorbance values of the T process were also higher than that of the C process. In other words, the increased temperature increased the amount of hydrolyzed/unfixed dyes passing into the bath. This was particularly evident in turquoise washing baths (Table 4). Since a large amount of hydrolyzate was removed in the first bath, lower absorbance values were obtained from the diffusion phase (third) compared to the first bath. This was more pronounced in blue and turquoise and it is clearly seen in the bath images shown in Figure 6. Another remarkable point is that the absorbance values of the turquoise washing baths were higher than those for the others, which is supported by Figures 3 and 4. This case, which means the removal of a higher amount of hydrolyzed/unfixed turquoise dye, is also supported by the higher color difference of turquoise-dyed fabrics compared to others (Table 2). NBs and T, which had higher absorbance values than C, showed that the soaping-off step could be eliminated in washings after reactive dyeing.

COD Measurements

The COD values of the soaping-off baths are given in Figure 7.

Figure 7.

COD values of soaping-off washing baths.

It was observed that both alternative washing processes (T-NBs) provided a reduction in COD values, that is, higher COD values were obtained in the washing processes performed with the conventional method (C). The COD values of the T process were at the lowest level. The higher COD values of the NBs process compared to T were thought to be associated with more hydrolyzate removal from the fiber surface.

Conclusion

To develop an environmentally friendly washing process, the elimination of detergent use in soaping-off, which is one of the washing steps after reactive dyeing that causes intense hydrolyzate pollution, was examined with temperature increase (T) and nanobubbles (NBs). The results showed that with new technologies such as the nanobubble generator, the use of detergents in the soaping-off step could be abandoned and more ecological washings could be conducted without compromising the fastness parameters. Since these green washing processes eliminated the use of soap, they reduced the COD values of the washing baths. With the use of nanobubble technology in washing processes, the extra treatment cost of wastewater with higher color levels and the cost of the generator should also be considered. However, it was thought that these extra costs could be compensated for by the reduced washing costs by not using soap and the lower treatment costs of washing wastewater that did not contain soap. In addition, although it was thought that the color loss caused by alternative washings would increase the dyeing cost, it should be taken into account that these losses were in very low amounts. The effects of nanobubble technology in other areas of textile are also worth examining.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors express their sincere thanks for funding this study with the project “Yeni ve Çevreci Teknolojilerin Reaktif Boyama Sonrası Yıkamada ve Atık Suyun Dekolorizasyonunda Kullanımı (Project Number: TEYDEB 1505 - 5180061)” by the Scientific and Technological Research Council of Turkey (TÜBİTAK).

References

Michailidi

Bomis

Varoutoglou

, et al. Fundamentals and applications of nanobubbles. Interf Sci Technol 2019; 30: 69–99.

Agarwal

Liu

Principle and applications of microbubble and nanobubble technology for water treatment. Chemosphere 2011; 84(9): 1175–1180.

Yang

Duan

Fornasiero

, et al. Very small bubble formation at the solid–water interface. J Phys Chem B 2003; 107(25): 6139–6147.

Zhang

Maeda

Craig

VSJ

. Physical properties of nanobubbles on hydrophobic surfaces in water and aqueous solutions. Langmuir 2006; 22(11): 5025–5035.

Temesgen

Bui

Han

, et al. Micro and nanobubble technologies as a new horizon for water-treatment techniques: A review. Adv Colloid Interface Sci 2017; 246: 40–51.

Arrojo

Benito

Martínez Tarifa

A parametrical study of disinfection with hydrodynamic cavitation. Ultrason Sonochem 2008; 15(5): 903–908.

Jyoti

Pandit

AB.

Ozone and cavitation for water disinfection. Biochem Eng J 2004; 18(1): 9–19.

Jyoti

Pandit

AB.

Water disinfection by acoustic and hydrodynamic cavitation. Biochem Eng J 2001; 7(3): 201–212.

Mezule

Tsyfansky

Yakushevich

, et al. A simple technique for water disinfection with hydrodynamic cavitation: Effect on survival of Escherichia coli. Desalination 2009; 248(1–3): 152–159.

10.

Sivakumar

Pandit

AB.

Wastewater treatment: A novel energy efficient hydrodynamic cavitational technique. Ultrason Sonochem 2002; 9(3): 123–131.

11.

Chen

Dong

, et al. Cleaning using nanobubbles: Defouling by electrochemical generation of bubbles. J Colloid Interface Sci 2008; 328(1): 10–14.

12.

Zhang

, et al. In situ AFM observation of BSA adsorption on HOPG with nanobubble. Chinese Sci Bull 2007; 52(14): 1913–1919.

13.

Liu

Craig

VSJ

. Cleaning of protein-coated surfaces using nanobubbles: An investigation using a quartz crystal microbalance. J Phys Chem C 2008; 112(43): 16748–16753.

14.

Noble

Brown

Jauregi

, et al. Protein recovery using gas-liquid dispersions. J Chromatogr B 1998; 711(1–2): 31–43.

15.

Fan

Tao

Honaker

, et al. Nanobubble generation and its applications in froth flotation (part II): Fundamental study and theoretical analysis. Min Sci Technol 2010; 20(2): 159–177.

16.

Zimmerman

Tesař

Bandulasena

HCH

. Towards energy efficient nanobubble generation with fluidic oscillation. Curr Opin Colloid Interface Sci 2011; 16(4): 350–356.

17.

Robello Samuel

Saveth

. Optimal design of progressing cavity pumps(PCP). J Energy Resour Technol 2006; 128(4): 275–279.

18.

Iijima

Gombodorj

Tachibana

, et al. Development of single nanometer-sized ultrafine oxygen bubbles to overcome the hypoxia-induced resistance to radiation therapy via the suppression of hypoxia-inducible factor-1α. Int J Oncol 2018; 52(3): 679–686.

19.

Garcia

Reduced water washing of denim garments. In: Paul

(ed.) Denim: Manufacture, finishing and applications. Cambridge: Elsevier, 2015, pp. 405–423.

20.

Jeanologia, https://www.jeanologia.com/garment/eflow

21.

Townsend

World natural fibre production and employment. In: Kozłowski

Mackiewicz-Talarczyk

(eds) Handbook of natural fibres: Types, properties and factors affecting breeding and cultivation, vol. 1. Cambridge: Elsevier, 2020, pp. 15–36.

22.

Opperskalski

Ridler

Siew

, et al. Preferred fiber & materials market report 2021, 2021, https://textileexchange.org/wp-content/uploads/2021/08/Textile-Exchange_Preferred-Fiber-and-Materials-Market-Report_2021.pdf

23.

Burkinshaw

SM.

Cellulosic fibres. In: Filarowski

(ed.) Physico-chemical aspects of textile coloration. West Yorkshire: John Wiley & Sons, 2016, pp. 249–358.

24.

Teng

Zhang

Application of a hydrolyzable cationic agent, poly(acryloxyethyl trimethylammonium chloride), in salt-free reactive dyeing for good dyeing properties. J Appl Polym Sci 2011; 122: 2741–2748.

25.

Dong

Hang

, et al. Study on the salt-free low-alkaline reactive cotton dyeing in high concentration of ethanol in volume. J Clean Prod 2019; 226: 316–323.

26.

Meng

Yan

, et al. Salt-free reactive dyeing of betaine-modified cationic cotton fabrics with enhanced dye fixation. Chinese J Chem Eng 2016; 24(1): 175–179.

27.

Siddiqua

Ali

Iqbal

, et al. Relationship between structure and dyeing properties of reactive dyes for cotton dyeing. J Mol Liq 2017; 241: 839–844.

28.

Suwanruji

Freeman

HS.

Design, synthesis and application of easy wash-off reactive dyes. Color Technol 2006; 122(1): 27–36.

29.

Arivithamani

Giri Dev

VR.

Salt-free reactive dyeing of cotton hosiery fabrics by exhaust application of cationic agent. Carbohydr Polym 2016; 152: 1–11.

30.

Chakraborty

JN.

Dyeing with reactive dye. In: Chakraborty

(ed.) Fundamentals and practices in colouration of textiles. Daryaganj, India: Woodhead Publishing, 2010, pp. 57–75.

31.

Chinta

Kumar

SV.

Technical facts & figures of reactive dyes used in textiles. Int J Eng Manag Technol 2013; 4(3): 308–312.

32.

Chattopadhyay

Chavan

Sharma

JK.

Salt-free reactive dyeing of cotton. Int J Cloth Sci Technol 2007; 19(2): 99–108.

33.

Gorensek

Dye-fibre bond stabilities of some reactive dyes on cotton. Dye Pigment 1999; 40: 225–233.

34.

Broadbent

Thérien

Zhao

Comparison of the thermal fixation of reactive dyes on cotton using infrared radiation or hot air. Ind Eng Chem Res 1998; 37(5): 1781–1785.

35.

King

Dyeing cotton and cotton products. In: Gordon

Hsieh

Y-L

(eds) Cotton: Science and technology. Cambridge: Woodhead Publishing, 2007, pp. 353–380.

36.

Allègre

Moulin

Maisseu

, et al. Treatment and reuse of reactive dyeing effluents. J Memb Sci 2006; 269(1–2): 15–34.

37.

Toprak

Anis

Textile industry’s environmental effects and approaching cleaner production and sustainability: An overview. J Text Eng Fash Technol 2017; 2(4): 429–442.

38.

Amin

Blackburn

RS.

Sustainable chemistry method to improve the wash-off process of reactive dyes on cotton. ACS Sustain Chem Eng 2015; 3(4): 725–732.

39.

Khatri

White

Padhye

, et al. The use of reflectance measurements in the determination of diffusion of reactive dyes into cellulosic fiber. Color Res Appl 2014; 39(1): 63–69.

40.

Broadbent

AD.

Reactive dyes. In: Broadbent

(ed.) Basic principles of textile coloration. Bradford: Society of Dyers and Colourists, 2001, pp. 332–357.

41.

Zhou

Cheng

, et al. Study on optimizing production scheduling for water-saving in textile dyeing industry. J Clean Prod 2017; 141: 721–727.

42.

Singh

Water saving technologies for textile chemical processing. In: Ul-Islam

Butola

(eds) Advanced functional textiles and polymers: Fabrication, processing and applications. Beverly, MA: Scrivener Publishing, 2019, pp. 153–170.

43.

Anis

Toprak

Kutlu

Sericin assisted eco-friendly reactive dyeing for cotton fabric. Cellulose 2019; 26(10): 6317–6331.

44.

Choudhury

AKR.

Sustainable chemical technologies for textile production. In: Muthu

(ed.) Sustainable fibres and textiles. Cambridge: Woodhead Publishing, 2017, pp. 267–322.

45.

Donkadokula

Kola

Naz

, et al. A review on advanced physico-chemical and biological textile dye wastewater treatment techniques. Rev Environ Sci Biotechnol 2020; 19(3): 543–560.

46.

Paździor

Bilińska

Ledakowicz

A review of the existing and emerging technologies in the combination of AOPs and biological processes in industrial textile wastewater treatment. Chem Eng J 2019; 376: 120597.

47.

Hasanbeigi

Price

A technical review of emerging technologies for energy and water efficiency and pollution reduction in the textile industry. J Clean Prod 2015; 95: 30–44.

48.

Habekost

Which color differencing equation should be used?

Int Circ Graph Educ Res 2013; 6: 20–33.

49.

Pisuntornsug

Yanumet

O’Rear

EA.

Surface modification to improve dyeing of cotton fabric with a cationic dye. Color Technol 2002; 118(2): 64–68.

Oxygen-enriched Nanobubbles for a Green Reactive Washing Process

Abstract

Keywords

Introduction

Experimental

Material

Method

Measurement

Results and Discussion

Color Coordinates

Color Strengths and Differences

Washing and Rubbing Fastness

Absorbance

COD Measurements

Conclusion

Footnotes

Declaration of conflicting interests

Funding

References