CHARACTERIZATION AND EXTRACTION OF CHROMIUM FROM SOLID WASTES OF THE LEATHER INDUSTRY - DOI: 10.13083/1414-3984/reveng.v23n4p326-335

Abstract

The increase in leather exportation in recent years has increased the generation of solid waste from leather industries in Brazil. Classified as Class I Residue, hazardous and presenting high contamination potential, correct disposal of these wastes in the environment is mandatory. Given the high content of nitrogen present in leather, there is growing interest for its utilization in agriculture, however to make this possible it is necessary to reduce the chromium content in the residue. Therefore, this study sought to characterize waste from the leather industry and develop a method for chromium extraction from it. Based on waste characterization, it was observed that waste from Wet Blue leather differs physically and chemically from finished leather strips, and although it presents a high nitrogen content (14 dag kg-1), for agricultural use most of the chromium must be extracted. The extraction method using a phosphoric acid solution resulted in 91.1% efficiency of Cr removal, where sequential extraction is a viable option both economically and environmentally.