New directions of utilization of wastes of leather production
In this paper, new directions in the use of tannery waste are considered. The analysis of problems of wastes of leather production is carried out, kinds of a waste are considered. In the work, known methods and technologies for the recycling of wastes of tannery used in the world are systematized. The main directions of waste utilization are determined: with preservation of fibrous structure, with preservation of collagen molecules and complete or partial decomposition of collagen by various methods. It is shown that the listed methods can be applied both for nontanned and for tanned skin wastes. Along with the methods of processing, the areas of use of products obtained as a result of technological processes are defined. It is shown that the use of high-tech processes with deep integration into the structure of the material requires large energy costs, but these processes can be implemented at the enterprises of the leather industry themselves. Less energy-intensive processes, including grinding the product and using it as a filler in various products, such as building materials, leather-like materials, are the most acceptable options for implementation on the territory of the Kyrgyz Republic. Most of the organic wastes of leather production have not yet been applied and are being exported to landfills, which, in addition to material losses, leads to pollution of the environment (mainly soil water) with protein hygiene products, as well as chromium-containing compounds. In order to reduce the negative impact of tannery waste on the environment, most of them tend to be involved in processing to obtain the final product. In the process of production of natural leather at all stages of the technological process of production (ritual, creasing, planing, grinding, doubling), due to uneven thickness and incorrect configuration of leather raw materials, 30-50% of its mass falls into waste. The type of waste generated and their quantity depend on the type of feedstock, the technology used in the processing stage, the destination of the final product, and so on.