Nanofiltration of Cork Wastewaters and Their Possible Use in Leather Industry as Tanning Agents

Cork processing wastewater is a very complex mixture of vegetal extracts and has, among other natural compounds, a very high content of phenolic/tannic colloidal matter that is responsible for severe environmental problems. In the present work, the concentration of this wastewater by nanofiltration was investigated with the aim of producing a cork tannin concentrate to be utilized in tanning. Permeation results showed that the permeate fluxes are controlled by both osmotic pressure and fouling/gel layer phenomena, leading to a rapid decrease of permeate fluxes with the concentration factor. The rejection coefficients to organic matter were higher than 95%, indicating that nanofiltration has a very good ability to concentrate the tannins and produce a permeate stream depleted from organic matter. The cork tannin concentrate obtained by nanofiltration and evaporation had total solids concentration of 34.8 g/l. The skins tanned by this concentrate were effectively converted to leather with a shrinking temperature of 7 degrees C

Ir Spectroscopy Studies of the Textile Materials Structures With Natural Dyes

The scientific study examines the functional groups of the oregano shell dye for dyeing textile materials, the expansion of color capabilities and capabilities capable of resisting microorganisms. The aim of the study is to create a natural additive to save resources, environmentally friendly, natural coloring products, easy to manufacture and use manufacturing technology. Extraction of the walnut shell is necessary when dyeing and finishing fabrics and textiles. At the present stage, it is relevant to obtain and study natural dyes for textile materials. The use of natural dyes will improve the hygienic properties of products and increase the environmental friendliness of the finishing process. Thanks to the active extraction of natural dyes and expanded color shades, the possibilities of introducing natural dyes into the textile industry in the future are high. This is due to the fact that the raw material base is extensive, and the compliance of natural dyes with international environmental standards, as well as one of the priorities provided for by the strategy, is the rational use of natural raw materials. IR spectroscopic studies of textile materials using the developed dyes were carried out in the work. To improve the quality of dyeing and chemical properties, various modifying components were added to the dyes. The use of the resulting coloring agent in the dyeing of textile fibers will replace the import of synthetic textile dyes

Heavy metal contents of various finished leathers

WOS: 000246634100001In this study, an investigation was made into the heavy metal content of leather articles. The metals concerned were cobalt, chromium, copper, zinc, lead and nickel as these metals may be subject to restrictions in some products because of their toxic characteristics. Insole leathers, upper leathers and garment leathers were studied as likely contaminating sources because of their extensive contact with the human body. Total amounts of heavy metals were initially measured by digestion. In addition, the possible amounts of heavy metals which would easily be extracted in use were extracted in aqueous and artificial perspiration solutions and analyzed using ICP-AES. It was concluded that the heavy metal content of finished leathers depended mainly on the chemicals used in production, and in particular high chromium contents in leather goods were determined. Also, small amounts of cadmium, zinc, lead, cobalt and copper were detected due to chemical and physical reactions during dyeing and finishing processes. The results of heavy metal contents were compared with limit values for leather and textile articles

Sequential secretion of collagenolytic, elastolytic, and keratinolytic proteases in peptide-limited cultures of two Bacillus cereus strains isolated from wool

WOS: 000266707700022PubMed ID: 19302303To characterize the secretion of proteolytic activities against keratin, collagen and elastin in liquid cultures of Bacillus cereus IZ-06b and IZ-06r isolated from wool. Growth of B. cereus IZ-06b and IZ-06r were characterized in batch culture. Both strains needed an organic nitrogen source, were able to grow on wool or peptone as sole carbon and nitrogen sources, and metabolized glucose, maltose and other simple sugars. Proteolytic activities were investigated in batch cultures grown in peptide-restricted, carbon-sufficient medium. Secretion of proteases was induced by peptide limitation while different proteolytic activities appeared sequentially in the growth medium. When the most available components of the peptone were depleted, collagenolytic and elastolytic proteases were produced. These were later replaced by the production of keratinolytic protease. B. cereus can adjust its proteolytic affinity profile in response to the supply of organic nitrogen and sequentially secrete proteases with activities targeted against increasingly inaccessible proteinous substrates as the nutritional availability in the environment deteriorates. Peptide-limited, carbon-sufficient growth media containing no proteinous substrates are well suited for protease production in B. cereus while growth conditions can be adjusted to optimize the proteolytic affinity profiles

Physical and Mechanical Properties of Cotton/Polyester Based Fibers for Shoe Uppers and Lining Products [1]

The purpose of the study was to evaluate the physical and mechanical properties of various textile materials based on polyester and cotton for shoe uppers and lining. For that purpose, the influence of the ratio of a mixture of cotton and polyester fibers on the quality of the fabric was investigated. As a result, fabrics with the same composition but different yarn numbers differed from each other in specified properties. With an increase in the content of polyester, all specified properties increase except for vapor permeability, which makes it possible to correctly select the composition of fabrics for shoes