The treatment of shavings,trimmings and splits of leather waste from tanneries has a potential to generate value-added products. In this study enzymatic treatment of leather waste was performed. This method utilizes a...The treatment of shavings,trimmings and splits of leather waste from tanneries has a potential to generate value-added products. In this study enzymatic treatment of leather waste was performed. This method utilizes alkaline protease produced by Bacillus subtilis in our laboratory by submerged fermentation. Optimum conditions of pH,time duration,temperature and concentration of enzyme were determined for maximum degradation of leather waste. The amount of degradation was measured by the release of amino acid hydroxyproline. Amino acid composition in the hydrolysate obtained by the enzyme hydrolysis was determined. This relative simple biotreatment of leather waste may provide a practical and economical solution.展开更多
Leather industry is an important light industry in China.Leather making requires a series of chemical treatment.Degreasing,unhairing and chrome tanning wastewaters are the main portions of tannery wastewater.Reclaimin...Leather industry is an important light industry in China.Leather making requires a series of chemical treatment.Degreasing,unhairing and chrome tanning wastewaters are the main portions of tannery wastewater.Reclaiming and reusing these wastewaters can eliminate 80% of COD,75% of BOD,95% of chromium and 93% of sulfuret,furthermore reduce environment impact,decrease treatment costs,save chemicals and water.Some application methods of wastewater reclamation and reuse for different operations were reported.The suitable reclamation and reuse technologies can enable leather making processes more rational,and realize the recovery and recycle of several chemicals in the tannery.Resourceful utilization of tannery wastewater should mate with renovating production technology,updating equipment,and must be guaranteed sufficiently by environmental protection measures.展开更多
Incomprehension concerning heavy metal containing finished solid leather wastes leads to environmental pollution.Conversion of these solid leather waste into energy and resource efficient products proves to be challen...Incomprehension concerning heavy metal containing finished solid leather wastes leads to environmental pollution.Conversion of these solid leather waste into energy and resource efficient products proves to be challenging.However,leather microfibres(LMF)were isolated from these heavy metal containing finished solid leather wastes.These heavy metal contain LMF further processed into metal reduction LMF.The metal reduction LMF were investigated for their heavy metal removal efficiency and toxicity analysis.The Cr(III)and Cr(VI)content of LMF was<1000μg/mL and<800μg/mL,respectively.Toxicity estimation was proved that the LMF had less than 1%.The study attempt to prepare reconstituted fibric materials(RFM)from metal reduction LMF and cellulose nanofibres(CNF).RFM were characterized for their physicochemical and mechanical properties.Hence,the study has proved a novel concept of RFM production which is recyclable,environmental friendly and cost effective.展开更多
Manufacture of eco-friendly chrome-free leather is of great significance for realizing sustainable development of leather industry.Conventional tanning theory believes that it is impossible to convert raw hide to leat...Manufacture of eco-friendly chrome-free leather is of great significance for realizing sustainable development of leather industry.Conventional tanning theory believes that it is impossible to convert raw hide to leather without the utilization of cross-linking agent(e.g.,chrome salts)among collagen fibers in raw hide.Here,we developed a brand-new leather manufacture strategy that relied on the composite dehydration media enabled self-driven directional dehydration mechanism to accomplish chrome-free leather manufacture for the first time,rather than followed the classic cross-linking mechanism that has been obeyed for more than one century in leather industry.We demonstrated that the essence of leather making is to regulate the water content in raw hide rather than to form cross-linkage among collagen fibers.The composite dehydration media comprised of anhydrous ethanol and molecular sieves(3A activated zeolite powder)successfully guaranteed continuous self-driven directional dehydration of raw hide by establishing stable water concentration gradient between raw hide and ethanol,which significantly increased the dispersity of collagen fibers in raw hide(with the water content reduced from 56.07%to 5.20%),thus obtaining chrome-free leather that is more ecological than chrome-tanned leather due to the elimination of any tanning agent.The as-prepared chrome-free leather exhibited outstanding tear force(174.86 N),tensile strength(24.56 N mm−2),elongation at break(53.28%)and dry-thermal stability,superior to chrome-tanned leather.Notably,the used compos-ite dehydration media was recyclable for chrome-free leather manufacture,therefore facilitating an environmentally benign leather manufacture process.Our investigations are expected to open up a new conceptual leather making strategy that is applicable for realizing substantial manufacture of eco-friendly leather.展开更多
文摘The treatment of shavings,trimmings and splits of leather waste from tanneries has a potential to generate value-added products. In this study enzymatic treatment of leather waste was performed. This method utilizes alkaline protease produced by Bacillus subtilis in our laboratory by submerged fermentation. Optimum conditions of pH,time duration,temperature and concentration of enzyme were determined for maximum degradation of leather waste. The amount of degradation was measured by the release of amino acid hydroxyproline. Amino acid composition in the hydrolysate obtained by the enzyme hydrolysis was determined. This relative simple biotreatment of leather waste may provide a practical and economical solution.
文摘Leather industry is an important light industry in China.Leather making requires a series of chemical treatment.Degreasing,unhairing and chrome tanning wastewaters are the main portions of tannery wastewater.Reclaiming and reusing these wastewaters can eliminate 80% of COD,75% of BOD,95% of chromium and 93% of sulfuret,furthermore reduce environment impact,decrease treatment costs,save chemicals and water.Some application methods of wastewater reclamation and reuse for different operations were reported.The suitable reclamation and reuse technologies can enable leather making processes more rational,and realize the recovery and recycle of several chemicals in the tannery.Resourceful utilization of tannery wastewater should mate with renovating production technology,updating equipment,and must be guaranteed sufficiently by environmental protection measures.
基金Dr.Senthil Rethinam acknowledges the funding support granted by the 2232-International Fellowship for Outstanding Researcher Program of TUBITAK(Project No:118C350).
文摘Incomprehension concerning heavy metal containing finished solid leather wastes leads to environmental pollution.Conversion of these solid leather waste into energy and resource efficient products proves to be challenging.However,leather microfibres(LMF)were isolated from these heavy metal containing finished solid leather wastes.These heavy metal contain LMF further processed into metal reduction LMF.The metal reduction LMF were investigated for their heavy metal removal efficiency and toxicity analysis.The Cr(III)and Cr(VI)content of LMF was<1000μg/mL and<800μg/mL,respectively.Toxicity estimation was proved that the LMF had less than 1%.The study attempt to prepare reconstituted fibric materials(RFM)from metal reduction LMF and cellulose nanofibres(CNF).RFM were characterized for their physicochemical and mechanical properties.Hence,the study has proved a novel concept of RFM production which is recyclable,environmental friendly and cost effective.
基金The National Natural Science Foundation of China(No.22178232,No.21978176)the National Natural Science Funds for Excellent Youth Scholars(No.21922808)+2 种基金the National Key Research and Development Program(No.2018YFC1901101)the Key Research and Development Program of Science and Technology Department of Sichuan Province(2021ZYCD009)the Program of Sichuan University Featured Research Groups in Engineering Disciplines.
文摘Manufacture of eco-friendly chrome-free leather is of great significance for realizing sustainable development of leather industry.Conventional tanning theory believes that it is impossible to convert raw hide to leather without the utilization of cross-linking agent(e.g.,chrome salts)among collagen fibers in raw hide.Here,we developed a brand-new leather manufacture strategy that relied on the composite dehydration media enabled self-driven directional dehydration mechanism to accomplish chrome-free leather manufacture for the first time,rather than followed the classic cross-linking mechanism that has been obeyed for more than one century in leather industry.We demonstrated that the essence of leather making is to regulate the water content in raw hide rather than to form cross-linkage among collagen fibers.The composite dehydration media comprised of anhydrous ethanol and molecular sieves(3A activated zeolite powder)successfully guaranteed continuous self-driven directional dehydration of raw hide by establishing stable water concentration gradient between raw hide and ethanol,which significantly increased the dispersity of collagen fibers in raw hide(with the water content reduced from 56.07%to 5.20%),thus obtaining chrome-free leather that is more ecological than chrome-tanned leather due to the elimination of any tanning agent.The as-prepared chrome-free leather exhibited outstanding tear force(174.86 N),tensile strength(24.56 N mm−2),elongation at break(53.28%)and dry-thermal stability,superior to chrome-tanned leather.Notably,the used compos-ite dehydration media was recyclable for chrome-free leather manufacture,therefore facilitating an environmentally benign leather manufacture process.Our investigations are expected to open up a new conceptual leather making strategy that is applicable for realizing substantial manufacture of eco-friendly leather.
