Dechroming of sludges from amino acid production through leaching for provisional remedy
Bildiriler > Özet Bildiri · 2025
Yazarlar: Nymul Islam, Tülin DENİZ ÇİFTÇİ, Bahri BAŞARAN, Al Mizan, Gülşah TÜRKMEN
8th International Congress on Innovative Aspects For Leather Industry, Türkiye, İzmir, Uluslararası, Sözlü Sunum, Özet Bildiri, 2025-2025, ss 96-96
Özet
<p>Leather industrial wastes contain a significant amount of hazardous substances like heavy metals, of</p><p><br></p><p>which chromium is one of the prominent ingredients, that are deposited in sludge along with other non-</p><p>structural substances. Insecure disposal of composite sludge paves the way for serious environmental</p><p><br></p><p>problems in soil and groundwater. This situation requires maneuvering for such conflicts through</p><p>adoptable environment-friendly disposal technologies.</p><p>The valorization of proteinaceous solid wastes such as chrome shaving scrapes has gained considerable</p><p>attention as a sustainable method for amino acid production. However, the hydrolysis process generates</p><p>chromium-rich sludge, posing significant challenges for safe disposal and environmental protection.</p><p>During hydrolysis, chromium tends to precipitate, and higher chromium content in the raw material</p><p>results in greater sludge volume.</p><p>In this study, a low-temperature acid leaching process using sulfuric acid (H2SO4) was developed and</p><p>optimized to achieve effective dechroming of the sludge and recover chromium in a reusable form. The</p><p>key parameters, including pH, molar concentration, time, and temperature, were systematically</p><p>examined. The optimum process conditions were determined to be pH:3, acid concentration: 0.3 M, time</p><p>2 hours, and temperature: 25 °C. Under these conditions, the chromium content in the sludge was</p><p>reduced from 5.55% to 0.21%, corresponding to the efficacy in chromium recovery of 96.5%. Speciation</p><p>analysis confirmed that 99.9% of the recovered chromium was in the trivalent Cr(III) form, with only</p><p>0.1% present as Cr(VI), indicating minimal toxicity.</p><p>The developed method offers a low-cost, energy-efficient, and environmentally friendly route for</p><p>detoxifying chromium-bearing sludge while promoting circular economy principles through resource</p><p>recovery and waste reuse. The outcomes of this research highlight the environmental and economic</p><p>feasibility of the dechroming process and open pathways for future studies on the safe application and</p><p>remediation potential of the treated sludge.</p>