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Vinhal JO, Nege KK, Lage MR, de M Carneiro JW, Lima CF, Cassella RJ. Adsorption of the herbicides diquat and difenzoquat on polyurethane foam: Kinetic, equilibrium and computational studies. Ecotoxicol Environ Saf 2017; 145:597-604. [PMID: 28802141 DOI: 10.1016/j.ecoenv.2017.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [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: 04/18/2017] [Revised: 08/01/2017] [Accepted: 08/02/2017] [Indexed: 06/07/2023]
Abstract
This work reports a study about the adsorption of the herbicides diquat and difenzoquat from aqueous medium employing polyurethane foam (PUF) as the adsorbent and sodium dodecylsulfate (SDS) as the counter ion. The adsorption efficiency was shown to be dependent on the concentration of SDS in solution, since the formation of an ion-associate between cationic herbicides (diquat and difenzoquat) and anionic dodecylsulfate is a fundamental step of the process. A computational study was carried out to identify the possible structure of the ion-associates that are formed in solution. They are probably formed by three units of dodecylsulfate bound to one unit of diquat, and two units of dodecylsulfate bound to one unit of difenzoquat. The results obtained also showed that 95% of both herbicides present in 45mL of a solution containing 5.5mgL-1 could be retained by 300mg of PUF. The experimental data were well adjusted to the Freundlich isotherm (r2 ≥ 0.95) and to the pseudo-second-order kinetic equation. Also, the application of Morris-Weber and Reichenberg equations indicated that an intraparticle diffusion process is active in the control of adsorption kinetics.
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Affiliation(s)
- Jonas O Vinhal
- Instituto de Química, Programa de Pós-Graduação em Química, Universidade Federal Fluminense, Outeiro de São João Batista s/n, Centro, Niterói, RJ 24020-141, Brazil; Departamento de Química, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil
| | - Kassem K Nege
- Instituto de Química, Programa de Pós-Graduação em Química, Universidade Federal Fluminense, Outeiro de São João Batista s/n, Centro, Niterói, RJ 24020-141, Brazil
| | - Mateus R Lage
- Instituto de Química, Programa de Pós-Graduação em Química, Universidade Federal Fluminense, Outeiro de São João Batista s/n, Centro, Niterói, RJ 24020-141, Brazil
| | - José Walkimar de M Carneiro
- Instituto de Química, Programa de Pós-Graduação em Química, Universidade Federal Fluminense, Outeiro de São João Batista s/n, Centro, Niterói, RJ 24020-141, Brazil
| | - Claudio F Lima
- Departamento de Química, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil
| | - Ricardo J Cassella
- Instituto de Química, Programa de Pós-Graduação em Química, Universidade Federal Fluminense, Outeiro de São João Batista s/n, Centro, Niterói, RJ 24020-141, Brazil.
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