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

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, H 2 O 2 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.

The comparison of Fenton and photo‐Fenton oxidation as a primary unit process for the treatment of raw textile wastewaters

“…The fact that the use of more H 2 O 2 than needed produces the hydroperoxyl radical (OOH•), which has a lower oxidation capacity, and this reduces the production rate of HO radicals (Abedinzadeh et al, 2018;Brink et al, 2017). When this study is compared with the previous studies (De Le on-Condés et al, 2019;GilPavas et al, 2017), it is observed that there are differences in removal rates. The main reason of difference in the removal rates is thought to be due to the application of the PFOP directly to the raw textile wastewater in this study.…”

The Utilization and Modeling of Photo‐Fenton Process as a Single Unit in Textile Wastewater Treatment

“…When this study is compared with previous studies performed on COD, SS, and color removal using the PFOP, the findings, which are about the process mechanism, seem to be similar notwithstanding the discrepancies in removal rates. [ 79,80 ] The main difference in removal rates, is thought to have been due to the direct application of the PFOP to the textile wastewater in this study.…”

Facile synthesis of TiO2@ZnO nanoparticles for enhanced removal of methyl orange and indigo carmine dyes: Adsorption, kinetics

“…The dye concentration in textile wastewater can reach 64.6 mg/L [ 38 ]. Then, the MO and IC equilibrium elimination experiment was realized in a glass vial with a capacity of 25 mL that holds 25 mL of dye solutions at various concentrations (7.5, 15, 30, 50, 75, and 100 mg/L) and 10 mg of nano-sorbent, which were stirred for 1440 min.…”