Sulfonated and gamma-irradiated waste expanded polystyrene with iron oxide nanoparticles, for removal of indigo carmine dye in textile wastewater

Cristina A De León-Condés; Gabriela Roa-Morales; Gonzalo Martínez-Barrera; Carmina Menchaca-Campos; Bryan Bilyeu; Patricia Balderas-Hernández; Fernando Ureña-Núñez; Helen Paola Toledo-Jaldin

doi:10.1016/j.heliyon.2019.e02071

Sulfonated and gamma-irradiated waste expanded polystyrene with iron oxide nanoparticles, for removal of indigo carmine dye in textile wastewater

Heliyon. 2019 Jul 15;5(7):e02071. doi: 10.1016/j.heliyon.2019.e02071. eCollection 2019 Jul.

Authors

Cristina A De León-Condés¹, Gabriela Roa-Morales², Gonzalo Martínez-Barrera³, Carmina Menchaca-Campos⁴, Bryan Bilyeu⁵, Patricia Balderas-Hernández², Fernando Ureña-Núñez⁶, Helen Paola Toledo-Jaldin¹

Affiliations

¹ Posgrado en Materiales, Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colon esquina Paseo Tollocan S/N, 50180, Toluca, Mexico.
² Centro Conjunto de Investigación en Química Sustentable, Universidad Autónoma del Estado de México - Universidad Nacional Autónoma de México (UAEM-UNAM), Carretera Toluca-Atlacomulco, km 14.5, Unidad El Rosedal, C.P. 50200, Mexico.
³ Laboratorio de Investigación y Desarrollo de Materiales Avanzados (LIDMA), Facultad de Química, Universidad Autónoma del Estado de México, Km.12 de la carretera Toluca-Atlacomulco, San Cayetano, 50200, Mexico.
⁴ Centro de Investigación en Ingeniería y Ciencias Aplicadas (CIICAp), Universidad Autónoma del Estado de Morelos (UAEM), Av. Universidad 1001, Col. Chamilpa, C.P. 62209, Cuernavaca Morelos, Mexico.
⁵ Department of Chemistry, Xavier University of Louisiana, Drexel Drive, Box 22, New Orleans, LA, 70125, USA.
⁶ Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca S/N, 52750, La Marquesa Ocoyoacac, Mexico.

Abstract

In this work, waste expanded polystyrene (WEPS) was irradiated with gamma rays, ranging doses from 100 kGy to 1,000 kGy. After irradiation, the WEPS had decrease on its glass transition temperature (Tg), as consequence of the scissions of its polymer chains. Then, the irradiated WEPS was sulfonated, and its degree of sulfonation (DS) was measured. The highest DS value, 46.6%, was obtained for an irradiation dose of 200 kGy. The sulfonated and irradiated polystyrene (denominated as iS-WEPS), was used as a support of iron oxide nanoparticles. Such composite system was denominated (FeO-NPs + iS-WEPS). The results show nanoparticle sizes of 31.5 nm containing 21.97% iron oxide. The composites followed a pseudo-second order model, with a maximum adsorption capacity of 20 mg/g, and an equilibrium time of 30 min, according to the Langmuir model. Moreover, the optimal conditions followed by the Fenton process were: pH = 3.2, H₂O₂ concentration = 0.32 mM/L, composite concentration (FeO-NPs + iS-WEPS) = 2 g/L, and a reaction time 20 min. Finally, 99% removal of indigo carmine dye was achieved, and a reduction of 83% of COD in textile wastewater.

Keywords: Analytical chemistry; Environmental science; Fenton process; Gamma radiation; Indigo carmine dye; Materials chemistry; Materials science; Nanotechnology; Physical chemistry; Sulfonation; Textile wastewater; Waste expanded polystyrene.