Water reuse in the post-tanning process: minimizing environmental impact of leather production. (13th December 2021)

• Record Type: Journal Article
• Authors: Klein, Rodrigo Miguel; Hansen, Éverton; de Aquim, Patrice Monteiro
• Is Part Of: Water science and technology. Volume 85:Number 1(2022)
• Page Start: 474
• Page End: 484
• Publication Date: 2021-12-13
• Subjects: leather -- liquid effluent -- post-tanning -- water reuse; Water -- Pollution; Sewage -- Purification; Water quality management; Periodicals; 628.168
• DOI: 10.2166/wst.2021.620
• Languages: English
• ISSNs: 0273-1223

Abstract

Abstract: Post-tanning wastewater is very diversified, as the post-tanning stage should meet the desirable properties of the leather for the final product, with low standardization of the process (compared to beamhouse and tanning). This makes post-tanning effluent reuse less feasible, and reuse in the post-tanning stage still needs to be explored. This work aims to evaluate the reuse of liquid effluents in the post-tanning process. The work methodology consisted of (i) characterization of water streams (groundwater, liquid effluent after primary treatment, and liquid effluent after secondary treatment); (ii) pilot-scale post-tanning tests using groundwater, primary effluent, and secondary effluent; (iii) characterization of the residual baths from pilot-scale tests (pH, conductivity, total solids, chemical oxygen demand, biochemical oxygen demand, chloride, hardness and oil and grease); and (iv) testing the leather obtained for total sulfated ash and organoleptic properties. Results showed that the primary effluent and the secondary effluent could be reused in pilot-scale post-tanning tests. There was an increase in the conductivity of the residual baths when liquid effluents were reused, which confirms the accumulation of salts in the effluents after their reuse. HIGHLIGHTS: Treated liquid effluents could be reused in the post-tanning process. Post-tanning water reuse can reduce the volume of water consumed and effluent generated by tanneries. Leather produced with reuse water achieved the desired organoleptic characteristics. Leather sulfated ash increased with water reuse, remaining within the technical limit.