Caracterização de resíduos de couro provenientes de um aterro industrial

Abstract

The leather and footwear industries produce large amounts of waste containing chromium, which potential for transformation from Cr3+, toxic, to Cr6+, genotoxic, is classified as Class I - hazardous. Along with the growing use of natural resources, there is also an increase in the number of challenges concerning a more sustainable development and a better management of waste generation and disposal processes. When generation of waste is unavoidable, its disposal in landfills is common and involves a series of negative factors, which can cause environmental and health damage, in addition to involving costs of disposal and land usage of industrial landfills. Recycling is an alternative to reduce these impacts. However, changes in the characteristics of these wastes due to several technologies and chemical treatments, and changes in their properties caused by the practice of placing these wastes in landfills, are poorly known. In this way, the aim of this study was to characterize the leather waste from an industrial landfill, through different analysis. The waste characterization (scraps and ashes of leather generated in laboratory) included proximate and ultimate analysis, pH, chemical elements; heating value, thermogravimetry, XRD and SEM/EDS. After evaluating the results, it was observed in the waste disposal that were stored for a longer period, the chromium, element of highest concentration and interest, suffered modifications, reaching a percentage 3% lower in the scraps and 15% on ashes than other in the other evaluated periods. The analysis parameters which enable the use of this waste as soil nutrients or in thermal treatment remained similar. The other variations in the concentration of chemical elements can be related to different processes, but cannot be connected with the disposal time in the landfill. In general, it was found that there were no significant changes in the characteristics of the leather waste, in the evaluated period and place where it was sampled. The stability of the parameters may be related to the disposal of this waste in an appropriate place, without contact with the ground and protected from weather changes.