Wafa Haddar

Development and optimisation of a non conventional extraction process of natural dye from olive solid waste using response surface methodology (RSM)

Dyes obtained from different natural sources have emerged as an important alternative to synthetic dyes. In this study, optimisation of natural colorant non-conventional extraction technique from olive waste was investigated using response surface methodology. The combined effects of extraction conditions on total phenolic content (TPC) and relative color strength (K/S) were studied using a three-level three-factor Box-Behnken design. The optimum conditions for dye extraction were found to be 0.14mol/L, 62.11min, 71.23°C and 4.5g for sodium hydroxide concentration, extraction time, temperature, and mass of the waste, respectively. The efficiency of extraction under these optimum conditions was found to be 1133.86mg/L of phenolics and relative colour strength (K/S) equal to 23.22. Further, Fourier Transform Infrared Spectroscopy was used to identify the major chemical groups in the extracted dye.

Green dyeing process of modified cotton fibres using natural dyes extracted from Tamarix aphylla (L.) Karst. leaves.

Abstract This research work involves an eco-friendly dyeing process of modified cotton with the aqueous extract of Tamarix aphylla leaves. During this process, the dyeing step was carried out on modified cotton by several cationising agents in order to improve its dyeability. The influence of the main dyeing conditions (dye bath pH, dyeing time, dyeing temperature, salt addition) on the performances of this dyeing process were studied. The dyeing performances of this process were appreciated by measuring the colour yield (K/S) and the fastness properties of the dyed samples. The effect of mordant type with different mordanting methods on dyeing quality was also studied. The results showed that mordanting gave deeper shades and enhanced fastness properties. In addition, environmental indicators (BOD5, COD and COD/BOD5) were used to describe potential improvements in the biodegradability of the dyebath wastewater. Further, HPLC was used to identify the major phenolic compounds in the extracted dye.

Sustainability issues of ultrasonic wool dyeing with grape pomace colourant

Abstract In this study, the ultrasound technique was investigated to dye wool fabrics with the natural extract obtained from grape pomace as a way of reducing time, temperature and environmental impact. Indeed, this natural material was very rich in total polyphenolic compounds and total flavonoids (which are, respectively, 310 (mg GAE/L) and 75 mg (CE/L)). Further, Fourier Transform Infrared Spectroscopy showed that the major chemical groups identified in the extracted dye and in the dyed wool fabrics are characteristics of phenolic compounds. The experimental findings of the dyeing process showed that ultrasound method could improve obviously the dye exhaustion and fixation which resulted in improving considerably the colour yield (K/S) and the fastness properties of dyed fabrics compared to the conventional heating method.

Improving dyeability of modified cotton fabrics by the natural aqueous extract from red cabbage using ultrasonic energy.

The concern regarding sustainable utilization of available resources is growing due to its global importance. In this paper, the dyeability of cotton fabrics with natural colorant extracted from red cabbage was improved by applying cationic groups on cotton fibers. Modification of cotton was carried using acid tannic, Rewin Os, Denitex BC and Sera Fast as cationic agents. The dyeing process was done by ultrasonic energy. The effects of the cationising agent amount, the dye bath pH, the dyeing temperature and duration, on the sonicator dyeing quality were studied. The performances of this process were evaluated by measuring the colour yield (K/S) and the dyeing fastness of the coloured cotton. Besides, modified cotton fibers were characterized by morphology analysis (SEM) and Fourier transform infrared (FTIR) spectra and compared to untreated cotton. Moreover, a two-level full factorial design was employed to optimize the sonicator dyeing process. Mathematical model equation and statistical analysis were derived by computer simulation programming applying the least squares method using Minitab 15. Best dyeing conditions were found to be: 10%, pH 11, 60min and 100°C respectively for the Sera Fast amount, dye bath pH, dyeing duration and temperature.

Extraction of Natural Dye from Waste Wine Industry: Optimization Survey Based on a Central Composite Design Method

The wine industry rejected large amounts of pressed grape pomace containing huge reserves of natural dyes that could be exploited in textile dyeing. The present paper aims to develop and optimize an extraction method of natural dye from grape pomace in order to dye wool fabrics. The influence of the main extraction conditions (grape pomace amount, sodium hydroxide concentration, extraction temperature and duration) on the dyeing performances of wool fabrics was studied. These performances were appreciated by measuring the color yield (K/S) of dyed wool fabrics. A central composite design method made with MINITAB 15 software was used for the optimization of the extraction method. The optimum conditions were found to be: concentration of sodium hydroxide of about 0.13 M, amount of grape pomace of about 69.56 g/l, extraction temperature of about 80 °C and extraction duration of about 70 min.

Use of Ultrasonic Energy for Enhancing the Dyeing Performances of Polyamide Fibers with Olive Vegetable Water

The present study reports the valorization of the olive vegetable water in natural dyeing. HPLC analysis of the phenolic extract obtained from the used olive vegetable water showed that the predominant flavonoid compounds were luteolin and apigenin. Hydroxytyrosol and various phenolic acids were also identified. This abundant waste was used as a possible dye bath for dyeing polyamide fabrics in conventional and ultrasonic techniques. It was found that these synthetic fibers possess high affinity to the olive vegetable water giving brownish shades with generally good fastness properties. Factors affecting the dyeing performances such as pH, temperature, and duration of the dyeing time were studied. Ultrasonic dyeing showed marked improvement in the dye uptake compared to the conventional heating. The results also showed that the use of this method enhanced some fastness properties compared to the conventional method. Moreover, it was found that using ultrasonic technique can reduce the concentration of polyphenols so that it reduced the chemical oxygen demand COD and biological oxygen demand BOD5 better than conventional heating method.

Development and Optimization of the Extraction Process of Natural Dye from Tamarix aphylla (L.) Karst. Leaves Using Response Surface Methodology (RSM)

The extraction of colorant from Tamarix aphylla (L.) Karst. leaves was optimized using response surface methodology (RSM). The combined effects of extraction conditions (sodium hydroxide concentration, sample weight, and extraction time and temperature) on the total phenolic content (TPC) and color yield (K/S) were studied using three-levels three-factors Box-Behnken design. The optimum conditions for dye extraction were found to be 0.25 mol/l, 65 min, 88 °C and 52.5 g/l for sodium hydroxide concentration, extraction time and temperature, and mass of the leaves powder respectively. The efficiency of extraction under these optimum conditions was found to be 1.12 g/l of phenolics and color yield equal to 11.20. Further, high-performance liquid chromatography analysis (HPLC) was used to identify the major phenolic compounds in the dye extract such as gallic acid, quercetin, luteolin, and kaempferon.

Application of anthocyanins as natural dye extracted from Brassica oleracea L. var. capitata f. rubra: dyeing studies of wool and silk fibres

Abstract Brassica oleracea L. var. capitata f. rubra (Red Cabbage) dye is composed mainly of natural pigment called anthocyanins used as a natural colourant. Wool and silk fibres were dyed with the aqueous extract obtained from red cabbage. The dyeing process was investigated and the combined effects of dyeing conditions on the colour yield parameter (K/S) were studied. Resulted fastness to wash, rubbing and light of the dyed fabrics were evaluated. Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD5) of the residual effluent were measured. Best dyeing conditions were found to be: 50 g/100 mL, pH 2, 60 min and 100 °C, respectively, for the red cabbage weight, pH, dyeing duration and temperature. Good fastnesses properties were found in both cases: for wool and silk fabrics. It was found also that the calculated biodegradability ratio (COD/BOD5) of the residual bath of dyeing wool and silk with red cabbage extract are lower than 1.5 which means that these baths are biodegradable.

Eco-friendly dyeing of modified cotton fabrics with grape pomace colorant: Optimization using full factorial design approach

ABSTRACT Grape pomace, which is a winery waste is studied and experimented to serve as a source of natural dyes that could be utilized in textile dyeing. In previous studies, it was found that grape pomace released from wine industry contains valuable resource of abundant natural coloring substances. The present work involves the optimization of dyeing process of cotton by natural colors extracted from grape pomace. The optimized dyeing conditions were; dyeing bath temperature 100°C, dyeing time 55 min, and dye bath pH 8. In addition, it was demonstrated that the dye bath of dyed cotton reduced the Chemical Oxygen Demand (COD) and the Biological Oxygen Demand (BOD)5 of the dye bath.

Upgrading of UV Protection Properties of Several Textile Fabrics by Their Dyeing with Grape Pomace Colorants

The desire to offer clothes protective properties against the harmful UV rays continues to attract the interest of researchers. Several works have been elaborated in this topic and have proved that the clothes do not protect sufficiently against the solar ultraviolet radiation. Their protectiveness depends on the fiber type, the fabric composition, the fabric construction and the dyeing method. This research presents a novel approach which target the improvement of the textile protective properties against UV rays by their dyeing with grape pomace aqueous extract. These properties were tested in combination with several fabrics (natural and synthetic) and mordants (potassium alum and ferrous sulphate). Through this study, it has been shown that the UV-protective properties of the several dyed fibers were upgraded after dyeing with the grape pomace extract, and is intensely relying on the types of fibers and mordants.