Utilization of used textiles for solid recovered fuel production

One of the current important issues is the management of used textiles. One method is recycling, but the processes are characterized by a high environmental burden and the products obtained are of lower quality. Used textiles can be successfully used to produce SRF (solid recovered fuels). This type of fuel is standardized by ISO 21640:2021. In the paper, an analysis of used textiles made from fibers of different origins was performed. These were acrylic, cotton, linen, polyester, wool, and viscose. A proximate and ultimate analysis of the investigated samples was performed, including mercury and chlorine content. The alternative fuel produced from used textiles will be characterized by acceptable parameters for consumers: a lower heating value at 20 MJ/kg (class 1-3 SRF), mercury content below 0.9 µg Hg/MJ (class 1 SRF), and a chlorine content below 0.2% (class 1 SRF). However, the very high sulfur content in wool (3.0-3.6%) and the high nitrogen content in acrylic may limit its use for power generation. The use of alternative fuel derived from used textiles may allow 3% of the coal consumed to be substituted in 2030. The reduction in carbon dioxide emissions from the substitution of coal with an alternative fuel derived from used textiles will depend on their composition. For natural and man-made cellulosic fibers, the emission factor can be assumed as for plant biomass, making their use for SRF production preferable. For synthetic fibers, the emission factor was estimated at the level of 102 and 82 gCO2/MJ for polyester and acrylic, respectively.

Mineral and potentially toxic element profiles in the soil-feed-animal continuum: Implications for public, environmental, and livestock health in three pasture-based sheep farming systems

Grazing livestock derive most of their mineral requirements from foraging. The presence of toxic elements in soils has become a significant concern for food safety and ecosystem services. Understanding the mineral content profiles in soil and forage is crucial for assessing animal health, predicting potential transfers of minerals or heavy metals into the food-chain, and assessing threats to the environment and human health. In this study, Na, Mg, P, K, Ca, Mn, Fe, Co, Cu, Zn, Se, As, Cd, Hg, and Pb were measured to determine the mineral status of three different pasture-based farming systems (with grazing sheep livestock) in a Spanish region of significant economic importance. A risk assessment evaluation of animal, environmental, and human health was performed on soil, forage, feed, serum, milk, and wool. Notably, traces of Pb, and As were identified in pastures in all farms. Our calculation of pollution indices revealed moderate levels of contamination by various elements, including Co, Cu, Zn, Se, As, Cd, Hg, and Pb. The two farms with more intense agrosystem practices showed a significant potential ecological risk, characterized by high soil levels of Hg and Cd. Animals from these farms also had high concentrations of these metals in wool. Although the target Hazard Quotient derived from milk consumption suggests that dairy products from this area are safe for consumption for adults, only milk from a dehesa farm (mix of woodland and pastureland) was free of potential health concerns related to Pb exposure. Our assessment of mineral profiles reveals a cohesive relationship between soil quality and derived animal products, particularly of the Merino sheep breeding and farming system. The results reveal the importance of adopting and reinforcing strategies to preserve dehesas as a sustainable and environmentally friendly agrosystem in the western Mediterranean region.

The influence of zinc-methionine bioplex supplementation to pregnant and lactating sheep on selected wool parameters

The most important nutrients affecting wool production include sulfur amino acids, such as methionine, and minerals, such as zinc, and their deficiency may cause wool production decrease. The aim of this study was to evaluate an effect of zinc and methionine chelate addition on the qualitative characteristics of Merino ewes wool and zinc content in wool fibers and on their surface. Histological evaluation of fibers was also performed. The study included 22 Polish Merino ewes divided into two groups: control and experimental (0.4 g chelates daily per head). The experiment lasted for 4 months (3.5 months of pregnancy and 2 weeks of early lactation). The length, thickness and breaking force of wool fibers were higher in the experimental group compared to the control group. Higher content of zinc in wool of sheep from the experimental group was also demonstrated. The histological structure of fibers from both groups did not differ, as the content of zinc on their surface. It can be concluded on the basis of the obtained results that the addition of chelates favorably influenced the thickness compensation of wool fibers and amount of wool obtained from sheep during pregnancy and early lactation, as well as mechanical features of wool.

Analysis of the hair coat of domestic cats with special focus on histological structure

The aim of the study was to characterize the hair coat of domestic cats. The research material consisted of hairs of different fractions collected in winter from female cats with a uniform hair coat colour: white,cream, red, brown and black. The hairs were divided into individual fractions, i.e. underhair, bristle hair and guard hair, and the following characteristics were evaluated: thickness, length, long and short axis length, stress at break and elongation. SEM (scanning electron microscope) images of all types of hair were taken and used to characterize each hair type and to calculate the number of scales per mm of hair length. The content of ions of various chemical elements was determined as well. Underhairs, which accounted for the largest percentage in the coat, were the thinnest and shortest, and had the most regular and distinct scale pattern. Guard hairs were the least numerous, but were the longest and thickest of all hairs examined. Both guard and bristle hairs had irregular scales with jagged edges. The cross-sections of these hairs revealed the presence of all the layers, i.e. the cuticle, cortex and medulla. In the underhair fraction the medulla was observed only in red cats. In all hairs the share of carbon, oxygen and sulphur ions was largest; these are the main omponents of hair protein, i.e. keratin.

Characterization of the hair coat of the Polish Konik and Hucul pony focusing on the physical features and histological structure of different hair types

The aim of the study was a comparative analysis of the hair coat of the Polish Konik and Hucul pony, focusing on the histological structure and physical parameters of the hair. Hair samples were obtained from 20 mares—10 of each breed. They were collected in winter, from the side of barrel, the mane, the tail, and front and rear fetlock. The hairs from the barrel were divided into overhair and underhair fractions. A higher percentage of underhair (about 70%) as compared to overhair (30%) was noted in both breeds. The overhair of the Polish Konik was about 50% longer than that of the Hucul pony, while the length of underhair did not differ between breeds. Both the overhair and the underhair of the Polish Konik were about 25% thicker than that of the Hucul pony. Elongation of particular types of hair did not differ significantly between the breeds. It was lowest for fetlock hair (about 45%) and highest for mane hair (about 55%). The histological structure of the cuticle layer of the hair did not differ between breeds.