Utilization of byproducts of sheep farming as organic fertilizer for improving soil health and productivity of barley forage.

Wool is a biodegradable fiber, rich in nutrients and can be recycled in soil as a fertilizer for maximum benefits. The present study was planned with the hypothesis that waste wool could be used as a nutrient source or manure to forage crops and aim of this study was to identify practicable recycling options of sheep based wastes in agriculture. In our study, we have compared the effect of different sheep based organic wastes on soil health, crop productivity and water use. Application of waste wool in soil significantly improved the fertility status of soil, and considerable improvement was also observed in organic carbon and nitrogen, i.e. around 30.8 and 32.6% higher over control. The activities of soil enzymes were 10-30% and 3-20% higher in waste wool treatment as compared to control and sheep based manures, respectively. Application of waste wool not only improved soil health but produced 50% higher grain and dry fodder yield of barley over control. The improvement in physical properties of soil with waste wool resulted in higher water use efficiency of the system. Our study will help in distinguishing choices for safe use of organic wastes along with up gradation of soil health and crop water utilization, particularly in nutrient poor soils of arid and semi-arid region of India.

Towards zero-waste processes: Waste wool derivatives as phosphate adsorbents and auxiliaries for textiles' natural dyeing.

The textile industry is a pillar of the manufacturing sector worldwide, but it still represents a significantly polluting production sector since it is energy-, water- and natural resource-intensive. Herein, waste wool that did not meet the technical requirements to be used for yarns and fabrics was recovered first to prepare materials for wastewater remediation, specifically for phosphate removal. The wool underwent an alkaline treatment, eventually saturated with FeCl3 and then left at room temperature or thermally treated to induce crosslinking/stabilisation, obtaining adsorbent panels. The main characterisation findings concerned the impact of alkaline treatment on morphology and structure; additionally, the samples with iron displayed a behaviour attributable to a crosslinking effect operated by Fe3+. Batch experiments showed that only samples with iron were efficient in phosphate adsorption, with a high removal percentage obtained in a wide pH range. Adsorption isotherms and kinetics were investigated, suggesting a complex system of interactions. Moreover, during the alkaline treatment necessary to prepare such wool-derived adsorbent panels, a significant amount of wool hydrolysates left in the solution was produced. These substances, in view of zero-waste procedures, were isolated and re-employed as dyeing auxiliaries. Preliminary results demonstrated that the wool hydrolysates enabled the dyeing of cotton with natural dyes, which is generally a tricky process.

Fine and high-performance protein fibers from meat goat hairs via manipulation of keratin alignment and crosslinkages.

We have converted waste coarse and short hairs of meat goats to high-value, fine, long, and elastic protein fibers via manipulation of keratin alignment and crosslinkages. The shortage of non-petroleum-based fibers has become one of the most prominent concerns. However, few technologies could convert such coarse hairs to fine and flexible fibers for textile uses due to limitations in extensions of fibers, less than 100% of their initial length, and poor flexibility retention of extended fibers, less than 20% of breaking elongation. Limited stretchability and flexibility retention of hair fibers mainly resulted from the difficulty in recovery of crosslinkages in stretched fibers. Here, we used a series of dithiols via multiple cycles of reduction, drawing, and oxidation to produce fine and flexible fibers from coarse and short wool for the first time. Dithiols with long backbones ensured sufficient crosslinkages in proteins after high ratios of drawings. Besides, long crosslinkages brought by dithiols secured sufficient movement between protein molecules and prevented of rupturing chains of protein molecules. As a result, short and coarse hairs of meat goats were turned into long and fine fibers, 350% of their original lengths and 54% of their original diameters, with excellent performance properties, with retentions of 170% of tenacity, and 50% of breaking elongation compared to original hairs. Also, a set of models developed to quantify the effects of extensions of fibers and structures of crosslinkers on the mechanical properties of fibers guides scientists and engineers on property improvement of materials via controlled crosslinkings.

A Facile Approach of Fabricating Electrically Conductive Knitted Fabrics Using Graphene Oxide and Textile-Based Waste Material.

This research investigated a feasible approach to fabricating electrically conductive knitted fabrics using previously wet-spun wool/polyacrylonitrile (PAN) composite fibre. In the production of the composite fibre, waste wool fibres and PAN were used, whereby both the control PAN (100% PAN) and wool/PAN composite fibres (25% wool) were knitted into fabrics. The knitted fabrics were coated with graphene oxide (GO) using the brushing and drying technique and then chemically reduced using hydrazine to introduce the electrical conductivity. The morphological study showed the presence of GO sheets wrinkles on the coated fabrics and their absence on reduced fabrics, which supports successful coating and a reduction of GO. This was further confirmed by the colour change properties of the fabrics. The colour strength (K/S) of the reduced control PAN and wool/PAN fabrics increased by ~410% and ~270%, and the lightness (L*) decreased ~65% and ~71%, respectively, compared to their pristine fabrics. The Fourier transform infrared spectroscopy showed the presence and absence of the GO functional groups along with the PAN and amide groups in the GO-coated and reduced fabrics. Similarly, the X-ray diffraction analysis exhibited a typical 2θ peak at 10° that represents the existence of GO, which was demolished after the reduction process. Moreover, the wool/PAN/reduced GO knitted fabrics showed higher electrical conductivity (~1.67 S/cm) compared to the control PAN/reduced GO knitted fabrics (~0.35 S/cm). This study shows the potential of fabricating electrically conductive fabrics using waste wool fibres and graphene that can be used in different application fields.

A novel tool for the adsorption of dsDNA: Electrochemical reduction of Pd nanoparticles onto reduced-keratin particles extracted from wool wastes.

This work outlines the fabrication of a novel electrochemical platform for the dsDNA adsorption, using one of the most sustainable materials, wool fabric waste, and Pd2+ ions. To develop a functional material with a significant adsorption capability, the waste wool was subjected to the chemical reduction process, and the keratin-SH (KerSH) particles were extracted in powder form. These particles were used in the adsorption of Pd2+ ions by monitoring with the UV-vis spectra. The dispersion of the KerSH-Pd2+ particles was subsequently drop-casted onto a glassy carbon electrode (GCE) and electrochemically reduced to the GCE/KerSH-PdNPs composite by chronoamperometry at -0.4 V for 500 s. It was found that the KerSH particles were self-assembled by revealing chemically attractive NH2 groups after the electrochemical PdNPs deposition. A GCE/KerSH-PdNPs composite was then employed in the electrochemical dsDNA detection by Differential Pulse Voltammetry (DPV), using the oxidation signals of guanine and adenine bases at 0.8 V and 1.2 V, respectively. Accordingly, relatively stable, repeatable, and reproducible dsDNA adsorption was ensured through the positively charged-NH2 groups of KerSH-PdNPs. This finding reveals the potential of textile waste for various electrochemical applications, such as DNA biosensors for environmental, pharmaceutical, and medicinal fields.