Leather waste

Leder, n. leather, -abfall, m., -abfkUe, m.pl. leather waste, leather cuttings, scrap leather, -abschnitt, m. leather cutting. 

Biomarkers that demonstrate chromium exposure under field conditions is under active investigation. Laboratory studies with Prussian carp (Carassius auratus gibelio) exposed for 3 to 9 days to 25 to 100 pg Cr /L or 50 to 200 pg Cr+3/L show a dose-dependent increase in the frequency of micronuclei in erythrocytes, and this increase is considered indicative of increasing DNA damage (Al-Sabti et al. 1994). Similar increases in micronuclei were observed in Prussian carp from the River Ljubjanica near chromium-containing outfalls from leather waste products in the Republic of Slovenia (Al-Sabti et al. 1994). 

Lead, lead oxide, leather wastes, LD-dust, lignite, lime, limestone, lithium carbonate, lithium fluoride, lithium hydroxide... 

An unspecified enzyme was also used to treat leather wastes [70]. The degradation of leather wastes yielded a water-soluble hydrolysate that could be concentrated and dried to produce fine flour, which was claimed to be used for a variety of commercial purposes. 

Bajza Z, Markovic I. Influence of enzyme concentration on leather waste hydrolysis kinetics. J Soc Leather Technol Chem 1999 83(3) 172—176. 

A method is proposed for using chrome tanned leather wastes produced by the footwear and clothing industry as fillers in polymer matrices. A technique for processing the composite obtained by continuous extrusion is also demonstrated. In order to evaluate the technique, a series of PVC-leather fibre composites was prepared and extruded through a flat die to produce sheets. The process produced a leather-like sheet that could be used in several applications. The influence of the filler content on the processability and final properties of the composite sheets was evaluated. The tests revealed that the sheets were flexible and exhibited suitable water absorption levels for several applications in the footwear and clothing industry. Finally, the tests showed that this composite could be formulated and processed at high productivity levels and at a low cost. 28 refs. 

Lead, lead oxide, leather wastes, LD-dust, lignite, lime, limestone, lithium carbonate, lithium fluoride, lithium hydroxide Magnesia, magnesium carbonates, magnetite, maleic anhydrate, manganese dioxide, metal powders, molding compounds, molybdenum, monocalciumphosphate (MCP)... 

Zhu D, Zhu Y, Cai H, Gao G, Gao C, Li B. Method for treating leather waste to produce coUagen with high added value by using enzyme bioreactor and membrane separator (Shenzhen Xianke Environment Protection Co., Ltd, People s Republic of China). Patent Priority CAN 145 194650 AN 2006 754551 (in Chinese). 

River Ljubjanica near chromium-containing outfalls from leather waste products in the Republic of Slovenia. 

Cabeza L.F., Taylor M.M., DiMaio G.L., Brown E.M., Mermer W.N., Carrio R., Celma P.J. and Cot J. (1998) Processing of Leather Waste Pilot Scale Studies on Chrome Shavings. Isolation of Potentially Valuable Protein Products and Chromium, Waste Management 18,211-218. 

The use of proteins as raw material for personal and home care products has been known for more than 60 years [58]. Both animal (e.g. leather waste) and plant-based proteins are available as raw materials. Nowadays mostly plant-based proteins (e.g. from wheat, soya bean, rice, peas) are used. Typically the natural proteins are degraded by hydrolysis (either chemically or enzymatically) and the respective protein hydrolysates are obtained. After purification and work-up they are used for skin and hair care formulations. The main claims are protection and care for hair and skin. Subsequent quarternization of the protein hydrolysates leads to products with high substantivity and conditioning effects, whereas acylation of the protein hydrolysates with fatty acids results in protein surfactants, the so-called protein fatty acid condensates. In the latter case, as already described for the sugar-based surfactants, the products are based completely on natural raw materials, namely fatty acids (from vegetable oil) and the protein or protein hydrolysate as the hydrophilic part in the surfactant molecule (Figure 4.6). The... 

Series P of activated carbons was prepared by carbonization in Nj (1123K) of chromium-tanned leather waste followed by activation in CO (1098K) for different periods of time to cover the 7-70% burn-off range (burn-off is included in the nomenclature of the samples). Adsorption of Nj (77K), CO2 (273K) and n-butane (273K) and preadsorption of n-nonane were determined in conventional gravimetric systems in order to characterize the carbons. 

Other protein materials utilized in the production of formaldeh> de-modified resins and plastics include dried blood, yeast, leather waste, and ege-table proteins such as gluten, zein, ground-nut protein, cottonseed meal, and keratin from hoofs, horn, hah, and feathers. 

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