Oxidative unhairing versus sulphide use – A critical comparison
Year: 2018
Type: conference-paper
Abstract: The conventional unhairing process is one of the most pollutant steps in the leather tanning process,\nwhich usually involves great amounts of sulphides, lime and soda ash, generating high BOD and COD\nvalues in the wastewater.\nIn this work, we have investigated different oxidative agents, combined or not with enzymes, as a\npossible replacement for sulphides in unhairing, focused on the possible industrial application of the\nmethod developed. Peroxymonocarbonate anion, persulfate anions (peroxymonosulfate and\nperoxydisulfate anion) and peroxynitrite anion have been chosen and the dehairing of bovine leather\nhas been performed. The performance has been compared in terms of dehairing ability, time,\nsuspended solids, pH, conductivity, COD and total nitrogen (Kjeldahl). All the tests were compared with\na pilot test (hair-saving sulphide unhairing) and with a hydrogen peroxide dehairing. The results show\nthe great ability of percarbonate, combined with enzymes, to give complete unhairing in 16 hours, no\ngrain damage in absence of sulphides, and great homogeneity after dyeing tests. The results, also,\nshowed a greater reduction of pollutants in the wastewater.
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2789011978