1
|
Uez DE, Hansen E, Osório DM, de Aquim PM. Reducing the pollution load of tannery wastewater and the atmospheric emission of hydrogen sulfide using modified tannin. Water Sci Technol 2023; 87:1542-1551. [PMID: 37001164 DOI: 10.2166/wst.2023.075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Industrial wastewater causes several environmental and health issues due to its composition, and hydrogen sulfide is one of the main contaminants from various industrial activities, including tannery wastewater treatment plants. This study aimed to evaluate the application of a modified tannin to remove hydrogen sulfide, chemical oxygen demand, total nitrogen, color, and turbidity from tannery wastewater and to reduce the atmospheric emission of sulfides. The wastewater was treated using modified tannin, aluminum sulfate, and a combination of both. Gaseous sulfide emissions were analyzed qualitatively using paper soaked in lead acetate. The qualitative methodology of hydrogen sulfide in the atmosphere was efficient to identify the most critical areas in the tannery. The wastewater treatment tests showed that the best option was the combination of both coagulants, in a 50:50 ratio, resulting in a total coagulant dosage of 3,000 mg/L. The removal efficiencies achieved were 13.8% sulfides, 23.3% chemical oxygen demand, 9.1% total nitrogen, 97.3% turbidity, and 96.4% color. This treatment technique promotes the replacement of 50% of the aluminum sulfate currently used in the tannery by a non-toxic coagulant and does not require chemicals to adjust the pH of the wastewater.
Collapse
Affiliation(s)
- Débora Eloísa Uez
- Postgraduate Program in Materials Technology and Industrial Processes, Feevale University, Novo Hamburgo, Brazil
| | - Everton Hansen
- Postgraduate Program in Materials Technology and Industrial Processes, Feevale University, Novo Hamburgo, Brazil; Chemical Engineering Department, Universidade do Vale do Rio dos Sinos - Unisinos, São Leopoldo, Brazil; Chemical Engineering Department, Centro Universitário Ritter dos Reis - Uniritter, Porto Alegre, Brazil E-mail: ;
| | | | - Patrice Monteiro de Aquim
- Postgraduate Program in Materials Technology and Industrial Processes, Feevale University, Novo Hamburgo, Brazil
| |
Collapse
|
2
|
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.
Collapse
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
| | | |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Hansen E, Rodrigues MAS, Aquim PMD. Wastewater reuse in a cascade based system of a petrochemical industry for the replacement of losses in cooling towers. J Environ Manage 2016; 181:157-162. [PMID: 27343433 DOI: 10.1016/j.jenvman.2016.06.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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: 03/04/2016] [Revised: 06/06/2016] [Accepted: 06/09/2016] [Indexed: 06/06/2023]
Abstract
This article discusses the mapping of opportunities for the water reuse in a cascade based system in a petrochemical industry in southern Brazil. This industrial sector has a large demand for water for its operation. In the studied industry, for example, approximately 24 million cubic meters of water were collected directly from the source in 2014. The objective of this study was to evaluate the implementation of the reuse of water in cascade in a petrochemical industry, focusing on the reuse of aqueous streams to replenish losses in the cooling towers. This is an industrial scale case study with real data collected during the years 2014 and 2015. Water reuse was performed using heuristic approach based on the exploitation of knowledge acquired during the search process. The methodology of work consisted of the construction of a process map identifying the stages of production and water consumption, as well as the characterization of the aqueous streams involved in the process. For the application of the industrial water reuse as cooling water, mass balances were carried out considering the maximum concentration levels of turbidity, pH, conductivity, alkalinity, calcium hardness, chlorides, sulfates, silica, chemical oxygen demand and suspended solids as parameters turbidity, pH, conductivity, alkalinity, calcium hardness, chlorides, sulfates, silica, chemical oxygen demand and suspended solids as parameters. The adopted guideline was the fulfillment of the water quality criteria for each application in the industrial process. The study showed the feasibility for the reuse of internal streams as makeup water in cooling towers, and the implementation of the reuse presented in this paper totaled savings of 385,440 m(3)/year of water, which means a sufficient volume to supply 6350 inhabitants for a period of one year, considering the average water consumption per capita in Brazil; in addition to 201,480 m(3)/year of wastewater that would no longer be generated.
Collapse
Affiliation(s)
- Everton Hansen
- Pure Sciences and Technology Institute, Feevale University, Highway RS 239, n. 2755 - Vila Nova, Novo Hamburgo, RS, Brazil.
| | | | - Patrice Monteiro de Aquim
- Pure Sciences and Technology Institute, Feevale University, Highway RS 239, n. 2755 - Vila Nova, Novo Hamburgo, RS, Brazil
| |
Collapse
|