title: Polyurethane foam loaded with sodium dodecylsulfate for the extraction of 'quat' pesticides from aqueous medium: Optimization of loading conditions.
abstract: The cationic herbicides paraquat, diquat and difenzoquat are largely used in different cultures worldwide. With this, there is an intrinsic risk of environmental contamination when these herbicides achieve natural waters. The goal of this work was to propose a novel and low-cost sorbent for the removal of the cited herbicides from aqueous medium. The proposed sorbent was prepared by loading polyurethane foam with sodium dodecylsulfate. The influence of several parameters (SDS concentration, HCl concentration and shaking time) on the loading process was investigated. The results obtained in this work demonstrated that all studied variables influenced the loading process, having significant effect on the extraction efficiency of the resulted PUF-SDS. At optimized conditions, the PUF was loaded by shaking 200mg of crushed foam with 200mL of a solution containing 5.0×10(-3)molL(-1) SDS and 0.25molL(-1) HCl, for 30min. The obtained PUF-SDS was efficient for removing the three herbicides from aqueous medium, achieving extraction percentages higher than 90%. The sorption process followed a pseudo second-order kinetics, which presented excellent predictive capacity of the amount of herbicide retained with time.
authors.affiliation: Departamento de Química, Universidade Federal de Viçosa, Av. Peter Henry Rolfs s/n, Viçosa, MG 36570-000, Brazil; 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.
authors.forename: Jonas O
authors.initials: JO
authors.lastname: Vinhal
authors.affiliation: Departamento de Química, Universidade Federal de Viçosa, Av. Peter Henry Rolfs s/n, Viçosa, MG 36570-000, Brazil.
authors.forename: Claudio F
authors.initials: CF
authors.lastname: Lima
authors.affiliation: 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. Electronic address: cassella@vm.uff.br.
authors.forename: Ricardo J
authors.initials: RJ
authors.lastname: Cassella
mesh_terms: D000327:Adsorption; D004178:Diquat; D006540:Herbicides; D010269:Paraquat; D011140:Polyurethanes / Q000737:chemistry*; D011720:Pyrazoles; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods*
chemical_list: D006540:Herbicides; D011140:Polyurethanes; D011720:Pyrazoles; D014874:Water Pollutants, Chemical; D012967:Sodium Dodecyl Sulfate; C031394:difenzoquat; C028279:polyurethane foam; D004178:Diquat; D010269:Paraquat
keywords: Cationic herbicides; Polyurethane foam; Sodium dodecylsulfate; Sorption