abstract
In tannery industries, before the tanning process, the hides are preserved through a curing stage. This involves applying 40-50% of common salt (NaCl) based on the fresh weight of the hide. One of the byproducts of the curing stage is contaminated salt, which is usually landfilled. In this work, the reclamation of this waste was achieved through iron-driven electrocoagulation of salt-derived brine (SdB) using iron electrodes. A current density of 371 A.m(-2) was applied for 16 min, yielding 88% removal of total organic carbon (TOC). The upscaling of this process requires suitable materials. Given that NaCl is highly corrosive to metal structures, this work investigated the corrosion resistance of different metals and alloys (aluminium, brass, carbon-steel, copper, AISI 304L and AISI 316L stainless steels) when exposed to SdB. The corrosion resistance was evaluated using different electrochemical techniques, including polarisation curves and electrochemical impedance spectroscopy (EIS). These measurements were made after immersing the metallic alloys in SdB for one hour and one month. The corrosion resistances of the six metals and alloys, ranked from highest to lowest, were as follows: AISI 316L > AISI 304 > aluminium > carbon-steel > brass > copper. This research provides valuable insights for future pilot-scale researchers and up-scaling efforts. By improving the circularity of the tannery industry and enhancing their competitiveness against conventional treatments, this work contributes to the advancement of the tannery industry.
keywords
SALINE WASTE-WATER
subject category
Computer Science; Science & Technology - Other Topics; Energy & Fuels
authors
Sarinho, L; Nunes, MI; Carvalho, P; Ribeiro, JP; Marques, C; Bastos, AC
our authors
António Alexandre Cunha Bastos
Assistant Researcher
Luana Sarinho
PhD Student
Pedro J. Carvalho
Assistant ProfessorGroups
G3 - Electrochemical Materials, Interfaces and Coatings
G4 - Renewable Materials and Circular Economy
Projects
Inovação na produção de subprodutos salinos em simbiose industrial (SIMBIOSALT)
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
acknowledgements
This work is financed by Portugal 2020 through European Regional Development Fund (ERDF) in the frame of CENTR02020 in the scope of the project SimBioSalt, CENTRO-01-0247-FEDER-069712. The work was developed within the scope of the project CICECO - Aveiro Institute of Materials, UIDB/50011/2020 UIDP/50011/2020 + LA/P/0006/2020, financed by national funds through the FCT/MCTES (PIDDAC) and CESAM (UIDP/50017/2020 UIDB/50017/2020 + LA/P/0094/2020), financed by national funds through the FCT/MCTES. J.P. Ribeiro and C. Marques acknowledges FCT for their PhD Grant (SFRH/BD/141133/2018) and BD/08959/2021, respectively.