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Klein RM, Hansen É, de Aquim PM. Water reuse in the post-tanning process: minimizing environmental impact of leather production. Water Sci Technol 2022; 85:474-484. [PMID: 35050896 DOI: 10.2166/wst.2021.620] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
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.
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Affiliation(s)
| | - Éverton Hansen
- Feevale University, 2755 RS 239 - Vila Nova, Novo Hamburgo, RS, Brazil E-mail: ; Centro Universitário Ritter dos Reis - UniRitter, 555 Orfanotrófio - Alto Teresópolis, Porto Alegre, RS, Brazil; Universidade do Vale do Rio dos Sinos, 950 Unisinos av., São Leopoldo, RS, Brazil
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Hansen É, Monteiro de Aquim P, Gutterres M. Current technologies for post-tanning wastewater treatment: A review. J Environ Manage 2021; 294:113003. [PMID: 34111598 DOI: 10.1016/j.jenvman.2021.113003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 05/22/2021] [Accepted: 06/02/2021] [Indexed: 06/12/2023]
Abstract
Leather post-tanning is responsible for producing effluents that are difficult to treat due to several recalcitrant pollutants. Dyes, tannins, and fatliquoring agents are mainly related to this characteristic. This study, as the state-of-the-art, attempts to systematically review treatment technologies applied in recent years to the post-tanning effluents. The Scopus database was used to identify articles related to post-tanning pollutants removal. Through the review, Advanced Oxidation Processes (AOPs) and adsorption proved to be good alternatives to increase the effluent biodegradability when applied before biological treatment. AOPs and adsorption were also efficient for the final polishing of the effluents, to reach the regulation standards for disposal, as well as enzymatic treatment. Furthermore, Membrane Separation Processes demonstrated good applicability when the reuse of the treated effluent is aimed.
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Affiliation(s)
- Éverton Hansen
- Federal University of Rio Grande do Sul - UFRGS, Post-graduation Program of Chemical Engineering, Laboratory for Leather and Environmental Studies -LACOURO, Eng. Luiz Englert Street, Porto Alegre, RS, Brazil; Feevale University, Institute of Pure Sciences and Technology, 2755, RS 239, Novo Hamburgo, RS, Brazil; Centro Universitário Ritter dos Reis - UniRitter, 555 Orfanotrófio, Porto Alegre, RS, Brazil; Universidade do Vale do Rio dos Sinos, Chemical Engineering Department, 950 Av. Unisinos, São Leopoldo, RS, Brazil.
| | - Patrice Monteiro de Aquim
- Feevale University, Institute of Pure Sciences and Technology, 2755, RS 239, Novo Hamburgo, RS, Brazil
| | - Mariliz Gutterres
- Federal University of Rio Grande do Sul - UFRGS, Post-graduation Program of Chemical Engineering, Laboratory for Leather and Environmental Studies -LACOURO, Eng. Luiz Englert Street, Porto Alegre, RS, Brazil
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Hansen É, Monteiro de Aquim P, Hansen AW, Cardoso JK, Ziulkoski AL, Gutterres M. Impact of post-tanning chemicals on the pollution load of tannery wastewater. J Environ Manage 2020; 269:110787. [PMID: 32430280 DOI: 10.1016/j.jenvman.2020.110787] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/29/2020] [Accepted: 05/13/2020] [Indexed: 05/09/2023]
Abstract
The leather industry uses a large amount of chemicals to transform a raw hide into finished leather. Chemicals are not fully taken up by leather and thus end up in tannery wastewater. Physicochemical and toxicological characterization of tannery effluents has been widely assessed. However, the characterization of processing chemicals and their relation to the pollution load of effluents remains unknown. Thus, this study aimed to assess a physicochemical and cytotoxic characterization of chemicals used in the leather post-tanning process and to evaluate the contribution of each chemical to the pollution load of raw wastewater. This study was performed using a leather post-tanning formulation applied by a large tannery located in Brazil. Deacidulation agents caused high conductivity and dissolved solids in wastewater. Retanning agents (natural and synthetic tannins) were responsible for the largest inorganic pollution load, and synthetic tannins were more toxic than natural ones. Fatliquoring agents released the highest chemical oxygen demand load in wastewater and they were the chemical group that presented the highest toxicity. Fixing agent and black dye provided inorganic pollution load to wastewater, and nitrogen pollution of wastewater was mainly related to the neutralizing retanner and the black dye.
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Affiliation(s)
- Éverton Hansen
- Federal University of Rio Grande do Sul - UFRGS, Post-graduation Program of Chemical Engineering, Laboratory for Leather and Environmental Studies -LACOURO, Rua Eng. Luiz Englert, s/n°, Porto Alegre, RS, Brazil; Centro Universitário Ritter dos Reis - UniRitter, 555 Orfanotrófio - Alto Teresópolis, Porto Alegre, RS, Brazil; Feevale University, 2755, RS 239, Vila Nova, Novo Hamburgo, RS, Brazil.
| | | | - Alana Witt Hansen
- Feevale University, 2755, RS 239, Vila Nova, Novo Hamburgo, RS, Brazil
| | | | | | - Mariliz Gutterres
- Federal University of Rio Grande do Sul - UFRGS, Post-graduation Program of Chemical Engineering, Laboratory for Leather and Environmental Studies -LACOURO, Rua Eng. Luiz Englert, s/n°, Porto Alegre, RS, Brazil
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de Aquim PM, Hansen É, Gutterres M. Water reuse: An alternative to minimize the environmental impact on the leather industry. J Environ Manage 2019; 230:456-463. [PMID: 30316036 DOI: 10.1016/j.jenvman.2018.09.077] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 08/21/2018] [Accepted: 09/22/2018] [Indexed: 06/08/2023]
Abstract
Tanneries are industries that may cause high environmental impact. Consequently, they are responsible for generating a large amount of wastewater with high concentrations of contaminants that require significant investment and operating costs in their treatment in order to accomplish the emission standards required by environmental legislation. This work has as main objective to minimize the environmental impact of the water used by tanneries through the study of reuse possibilities of wastewater tanning floats. The major concern is related to the pollutant chromium in the environment, since it is the tanning product that gives the best characteristics to leather and consequently the most used product. The reuse tests were performed on pilot and industrial scales. During the experiments, the following process control parameters were evaluated: pH, density, acid-base indicators for hide and shrinkage temperature. To validate the water reuse in tanneries, samples of wet-blue leather and residual floats were collected from pilot and industrial processes to perform chemical analyses to prove the validity of the process with reuse. Research has shown that reuse techniques, when properly evaluated, can be used in industries. In addition to reducing water demand, the reuse of wastewater in tanning processes minimizes the disposal of the wastewater with chromium and uses the residual chromium float.
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Affiliation(s)
- Patrice M de Aquim
- FEEVALE University, Campus II, RS 239, N°. 2755, Vila Nova, Novo Hamburgo, RS, Brazil
| | - Éverton Hansen
- FEEVALE University, Campus II, RS 239, N°. 2755, Vila Nova, Novo Hamburgo, RS, Brazil; Federal University of Rio Grande do Sul - UFRGS, Chemical Engineering Department, Laboratory for Leather and Environmental Studies -LACOURO, Rua Eng. Luiz Englert, s/n°, Porto Alegre, RS, Brazil; Centro Universitário Ritter dos Reis - UniRitter, 555 Orfanotrófio - Alto Teresópolis, Porto Alegre, RS, Brazil.
| | - Mariliz Gutterres
- Federal University of Rio Grande do Sul - UFRGS, Chemical Engineering Department, Laboratory for Leather and Environmental Studies -LACOURO, Rua Eng. Luiz Englert, s/n°, Porto Alegre, RS, Brazil
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