Disposal of chromium-containing collagenous waste,generated during the processing of leather,is a problem that is being addressed not only in the United States,but also world-wide.Alternative disposal methods are bein...Disposal of chromium-containing collagenous waste,generated during the processing of leather,is a problem that is being addressed not only in the United States,but also world-wide.Alternative disposal methods are being sought because of environmental concerns and rising landfill costs.We have developed a process in which this waste can be treated with a variety of enzymes to extract gelatin and a hydrolysate.These recovered protein fractions,practically devoid of chromium,could be used in a wide range of products,including adhesives,cosmetics,films,encapsulating agents,animal feed and fertilizer.A chromium product is also isolated that can be chemically treated and recycled back into the tanning process.Finally,we have shown,by using a computer-assisted process simulation and cost estimation,that a profit could be realized by the tanneries,not only by reducing the need to landfill but also from the return from the sale of the protein products.展开更多
Results and Discussion The composition of chrome shavings,a by-product of leather production,will vary from batch to batch since there is variation in both the hides and the tanning processes employed.Analysis of shav...Results and Discussion The composition of chrome shavings,a by-product of leather production,will vary from batch to batch since there is variation in both the hides and the tanning processes employed.Analysis of shavings from several commercial sources yielded the following relatively narrow ranges of values for pH(3 to 4),moisture(50%to 54%),ash(8%to 14%),TKN(14%to 16%),fat(0.1%to 1.8%)and chromium(3%to 4%as chromic oxide).If the pH is outside of this range,it would have to be adjusted to assure the success of the process;other values used to characterize the shavings are not critical.展开更多
文摘Disposal of chromium-containing collagenous waste,generated during the processing of leather,is a problem that is being addressed not only in the United States,but also world-wide.Alternative disposal methods are being sought because of environmental concerns and rising landfill costs.We have developed a process in which this waste can be treated with a variety of enzymes to extract gelatin and a hydrolysate.These recovered protein fractions,practically devoid of chromium,could be used in a wide range of products,including adhesives,cosmetics,films,encapsulating agents,animal feed and fertilizer.A chromium product is also isolated that can be chemically treated and recycled back into the tanning process.Finally,we have shown,by using a computer-assisted process simulation and cost estimation,that a profit could be realized by the tanneries,not only by reducing the need to landfill but also from the return from the sale of the protein products.
文摘Results and Discussion The composition of chrome shavings,a by-product of leather production,will vary from batch to batch since there is variation in both the hides and the tanning processes employed.Analysis of shavings from several commercial sources yielded the following relatively narrow ranges of values for pH(3 to 4),moisture(50%to 54%),ash(8%to 14%),TKN(14%to 16%),fat(0.1%to 1.8%)and chromium(3%to 4%as chromic oxide).If the pH is outside of this range,it would have to be adjusted to assure the success of the process;other values used to characterize the shavings are not critical.
