Leather wastes tanned with chromium are generated during the production process of leather, hence the wastes from hand crafted goods and footwear industries are a serious environmental problem. The thermal treatment of leather wastes can be one of the treatment options because the wastes are rich in chromium and can be used as a raw material for sodium chromate production and further to obtain several chromium compounds. The objective of this study was to utilize the chromium from leather wastes via basic chromium sulfate production to be subsequently applied in a hide tanning. The obtained results have shown that this is the first successful attempt to achieve desired base properties of the product. The result was achieved when the following conditions were applied: a molar ratio between sodium sulfite and sodium dichromate equal to 6; reaction time equal to 5 min before addition of sulfuric acid; pH of sodium dichromate solution equal to 2. Summarizing, there is an opportunity to utilize the dangerous wastes and reused them in the production scheme by minimizing or annulling the environmental impact and to attend a sustainable process development concept.
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http://dx.doi.org/10.1016/j.jhazmat.2009.11.090 | DOI Listing |
J Hazard Mater
December 2024
College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China; Nanhai Institute of Harbin Engineering University, Sanya 572024, China. Electronic address:
The rational use of solar energy to achieve photothermal conversion is an attractive strategy to promote the efficient removal of radioactive Cs and Sr from nuclear wastewater. Herein, a photothermal adsorbent of composite aerogel with three-dimensional porous structure is fabricated by integrating prussian blue analogues (PBAs) and straw biochar into the chitosan (CS) and waste leather scrap hydrolysate (WLSH) aerogel matrix (CS/WLSH/C/PBAs). The local heating effect generated by CS/WLSH/C/PBAs aerogel induce to generate steam, accelerating the enrichment of Cs and Sr in the solution, which increase their interaction with the CS/WLSH/C/PBAs and improves their adsorption rates and capacities.
View Article and Find Full Text PDFMaterials (Basel)
November 2024
Department of Physical Aspects of Ecoenergy, The Institute of Fluid-Flow Machinery Polish Academy of Sciences, Fiszera 14 St., 80-231 Gdańsk, Poland.
Leather waste contains up to 10% nitrogen (N); thus, combustion or gasification only for the energy recovery would not be rational, if safety standards are met. On the other hand, the chromium (Cr) content exceeding 5% in half of the waste stream (/) is too significant to be applied in agriculture. In this work, four acid hydrolysates from leather waste shavings, both wet-white free of Cr and wet-blue with Cr, were used: two with a mixture of acids and supplemented with Cu, Mn, and Zn, and the other two as semi-products from collagen extraction using hydrochloric acid.
View Article and Find Full Text PDFBiomacromolecules
December 2024
College of Bioresources Chemical and Materials Engineering (College of Flexible Electronics), Shaanxi University of Science & Technology, Xi'an 710021, China.
The development of engineered hydrogels with high strength, self-recovery, and adhesion is essential for applications requiring resistance to large deformations and cyclic loading. Herein, a triple-network (TN) hydrogel with ultrahigh compressive strength, strong adhesion, and good self-recovery was constructed by using tannic acid-modified chrome leather scrap hydrolysate as the first network, polyacrylamide as the second network, and poly-2-propenamide-2-methylpropanesulfonic acid as the third network. The ultrahigh (70 MPa compressive strength and 95% compression deformation) TN hydrogels were effectively created, which is attributed to the synergy of the three networks.
View Article and Find Full Text PDFBiodegradation
December 2024
Department of Environmental Engineering, Middle East Technical University, 06800, Ankara, Turkey.
This study focused on a new approach for valorization of both ground tire rubber (GTR) and nitrate-containing wastewater via simultaneous devulcanization and denitrification. Initially, sulfur-based autotrophic denitrifiers were successfully enriched from three different seed sludge sources, biological nutrient removal (BNR) sludge, anaerobic digester sludge and BNR sludge of a leather organized industrial zone WWTP. Average nitrate removal efficiencies were 96-98%.
View Article and Find Full Text PDFJ Hazard Mater
November 2024
Key Laboratory of Environment Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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