RECOVERY OF CHROMİUM FROM SLUDGE GENERATED DURİNG THE PRODUCTİON OF HYDROLYSATE FROM CHROME CONTAINING LEATHER SHAVING WASTE
Project no. 32854 · Status: Kapanmış (Yayın bekleniyor) · 2025
Summary
<p>The valorization of proteinaceous solid wastes (shaving dust) generated during the shaving process in the leather industry has recently turned into a technical application. During the production of amino acids from shaving dust, sludges with high chromium content are formed. The chromium content of this sludge is seen as a significant problem for its safe disposal. In this study, a leaching process carried out at low temperature using sulfuric acid (H₂SO₄) was developed and optimized for the recovery of chromium (Cr) from the said sludge. Parameters such as pH, molar concentration, time, and temperature were systematically investigated; the optimum conditions were determined as pH 3, 0.3 M, 2 hours, and 25 °C. While the Cr content in the sludge before the process was 5.55%, this ratio decreased to 0.21% in the residue after the process, and 96.5% of the total chromium was recovered under optimum conditions. The speciation analysis showed that 99.9% of the recovered chromium was in the Cr(III) form, which has low toxicity, and the Cr(VI) ratio remained at a negligible level of 0.1%. This method, since it does not involve energy-intensive steps, enables the conversion of hazardous wastes into reusable form through low-cost processes and allows the reuse of leather industry wastes through circular economy. The results obtained demonstrate the economic and environmental feasibility of the method and have the potential to pave the way for future pilot-scale applications and the re-evaluation of post-process wastes and by-products.</p>