Composites Based on Natural Polymers and Microbial Biomass for Biosorption of Brilliant Red HE-3B Reactive Dye from Aqueous Solutions

Natural polymers have proven to be extremely interesting matrices for the immobilization of microbial biomasses, via various mechanisms, in order to bring them into a form easier to handle—the form of composites. This article aimed to study composites based on a residual microbial biomass immobilized in sodium alginate via an encapsulation technique as materials with adsorbent properties. Thus, this study focused on the residual biomass resulting from beer production (Saccharomyces pastorianus yeast, separated after the biosynthesis process by centrifugation and dried at 80 °C)—an important source of valuable compounds, used either as a raw material or for transformation into final products with added value. Thus, the biosorptive potential of this type of composite was tested—presenting in the form of spherical microcapsules 900 and 1500 μm in diameter—in a biosorption process applied to aqueous solutions containing the reactive dye Brilliant Red HE-3B (16.88–174.08 mg/L), studied in a batch system. The preparation and characterization of the obtained polymeric composites (pHPZC, SEM, EDS and FTIR spectra) and an analysis of different equilibrium isotherms (Langmuir, Freundlich and Dubinin-Radushkevich—D–R) were investigated in order to estimate the quantitative characteristic parameters of the biosorption process, its thermal effects, and its possible mechanisms of action. The modelling of the experimental data led to the conclusion that the studied biosorption process took place after reaching the Langmuir isotherm (LI), and that the main mechanism was possibly physical, being spontaneous and probably exothermic according to the values obtained for the free energy of biosorption (E = 8.45–13.608 kJ/mol, from the DR equation), as well as the negative values for the Gibbs free energy and the enthalpy of biosorption (ΔH0 = −87.795 kJ/mol). The results obtained lead to the conclusion that encapsulation of this residual microbial biomass in sodium alginate leads to an easier-to-handle form of biomass, thus being an efficient biosorbent for static or dynamic operating systems for effluents containing moderate concentrations of reactive organic dyes.

Effect of Perforation Dyeing Technique on Color Difference, Colorfastness, and Basic Density of Living Red-Heart Chinese Fir

Red-heart Chinese fir is an excellent geographic provenance of Cunninghamia lanceolata, with high-value red heartwood. However, the formation of red heartwood is usually slow. To quickly cultivate red-heart Chinese fir, we studied perforation dyeing technology on living trees that were 7 years old and efficient in high-value red heartwood formation. Reactive dye (%), penetrant (%), KH2PO4 (%), and pH were selected as influencing factors, and an orthogonal test (L9(3)4) was used. The results showed that the total color difference between the experimental and CK groups ranged from 13.74 to 26.86 NBS, which was a significant visual perception (above 12 NBS). The total color difference before and after soaking in water for 6 h ranged from 2.30 to 5.12 NBS, which belonged to the detectable and identifiable value of the human eye (2~5 NBS). After the injection of the dye liquid, the wood basic density (WBD) was significantly affected after one year. After a comprehensive analysis of wood color difference, colorfastness, and WBD of the orthogonal test, the best dyeing process of juvenile red-heart Chinese fir was reactive dye: 0.8%, penetrant: 0.05%, KH2PO4: 0.3%, and pH: 3.5. The results of this study can provide a reference to improve the value of red-heart Chinese fir, a fast-cultivated, high-value decorative wood material.

REACTIVE DYE PRINTING ON COTTON FABRIC USING MODIFIED STARCH OF WILD TARO CORMS AS A NEW THICKENING AGENT

This study investigated the use of a thickening agent derived from modified starch of wild taro corms in the screen printing of cotton fabric using reactive dye. The best conditions for developing the print paste and steaming time in order to obtain maximum color yield were established. The results revealed impressive color fastness properties in the printed samples; although, the printed fabric possessed slightly lesser tensile and tear strength, in comparison with the unprinted fabric. The printed fabric also exhibited increased bending stiffness properties. Largely, this study reveals that the printing paste containing the thickening agent derived from carboxymethyl starch within wild taro corms can be utilized in the printing of cotton fabric using reactive dye.

Adsorbent from Textile Waste for Removal of Textile Reactive Dye from Water – Equilibrium Adsorption and Kinetics

The removal of textile reactive dye from an aqueous solution on a new adsorbent prepared from waste cotton knitted fabric was investigated in this study. Waste cotton textile, used for the production of adsorbents, is a by-product of the cutting of stacked parts of cotton knitwear planned for the production of women’s T-shirts. The degree of efficiency of a paper pattern determines the amount of collected waste. The qualitative and quantitative characterization of the new adsorbent showed carbon and oxygen to be dominant in the chemical composition. A longer contact time means a greater amount of dye on the adsorbent, i.e. the dye concentration in the solution decreases with the duration of the adsorption process. The percentage of removed dye decreases with an increase in the initial dye concentration in the solution. However, the actual amount of adsorbed dye increases as the initial dye concentration increases. The results for equilibrium adsorption show that the Langmuir isotherm can be used for the interpretation of reactive dye adsorption on a new adsorbent. The pseudo-first order model can be fully used to describe the kinetics of dye adsorption on an adsorbent, with respect to valid results for statistical indicators. Based on the results, it can be concluded that the new adsorbent obtained from waste textiles has the potential to remove textile reactive dye from aqueous solutions.

Synthesis of material MOFs (Fe-BTC) by mechanic-chemical method and its application in the reactive dye degradation

Nano Fe-BTC materials were successfully synthesized by mechanical chemical grinding method. Samples were characterized by X-ray difraction (XRD), Fourier-transform infrared spectroscopy (FTIR), N2 adsorption–desorption, Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS). SEM image of Fe-BTC-60 showed the particle size of 40–60 nm. Fe-BTC nanocomposites were tested for the photocatalytic degradation of reactive yellow 145 (RY-145) in aqueous solution. Fe-BTC composites exhibited high photocatalytic activity. Thus, at pH of 3 and high initial concentration of 100 mg RY-145/L, removal efficiency reached the value of 97.45% after 90 min of reaction.

Cotton canvas trousers washing: an inception of a new horizon in apparel industry

Nowadays, fashionable trouser (denim) with washing effect is very popular, especially among the youth. The global fashion trend has led to the development of diverse washing processes that are predominantly applied to denim fabric. However, no known research has studied the application of the washing effect on canvas fabric. Therefore, this paper aims to make fashionable canvas fabric trousers by applying various washing effects. To do so, ready-to-dye canvas fabric trouser was constructed, then dyed with dischargeable reactive dye (Lava). Chemical washing processes such as whisker, enzyme, and PP spray were then applied on dyed canvas trousers. Finally, developed samples were being characterized by mechanical tests such as tensile strength, tear strength, stiffness, abrasion, pilling, colorfastness to wash, and colorfastness to rubbing. Besides, to evaluate fabric surface, various tests such as Scanning Electronic Microscope (SEM), Reflectance% values have also been characterized. Tensile strength, tear strength, stiffness, reflectance% value, and wear index% changed significantly for every subsequent process. The tensile strength of finished trousers was 489.87 N at warp and 350.57 N at weft direction and the tear strength was 48.01 N and 35.56 N at warp and weft direction, respectively. The reflectance% value of 18.74 was observed at the PP sprayed area. Overall, the research revealed the possibility of using cotton canvas as a pair of fashionable trousers contributing to the development of the apparel industry.

Synthesis of Fe/H-ZSM-5 material by chemical vapor deposition method and its application for degradation of reactive dye

Fe containing nano ZSM-5 composites (Fe/H-ZSM-5) were successfully prepared by chemical vapor deposition method. The physical properties of Fe/H-ZSM-5 were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), N2 adsorption-desorption isotherm (BET) analysis. Effects of pH and H2O2 concentration were investigated. The best conditions were found to be pH of 3; 0.3 g.L−1 catalyst and reaction time of 60 min at room temperature. The novel Fe/H-ZSM-5 composite exhibited highly photocatalytic performance of RR-195 degradation and the conversion reached to the value of 92.3 % for after 60 min of reaction.