Leaching toxicity and ecotoxicity of tanned leather waste during production phase

Abstract

This paper investigated the environmental impact of leather from production phase via identifying the hazardous substances (such as HCHO, Cr[VI]), leaching toxicity and ecotoxicity, with special emphasis on chrome or chrome-free. The hazardous substances of concern in various tanned leather waste from processing and commercial product were found lower than the present criterion for the eco-label product, different from the leaching toxicity and ecotoxicity. Several of the chrome-leather samples might be classified as hazardous waste for total chrome leached beyond the limitation though no Cr(VI) was leached out. Whereas the ecotoxicity toward photobacterium phosphoreum of leather samples from technology flow indicated chrome-tanned samples (S1–S3) was more toxic than corresponding chrome-free samples (S4–S6), confirming the crucial environmental impact of the tanning procedure. The increased toxicity of finished leather (S3 and S6) also revealed the significance of the finishing procedure in developing environment-friendly leather products. The multiple linear regression further demonstrated the positive correlations of the ecotoxicity of leather with leached total Cr, HCHO, and anionic polyelectrolyte. These results discerned the crucial procedures and chemicals to improve the process safety of leather.