Adsorptive removal of methylene blue from aquatic environments using thiourea-modified poly(acrylonitrile-co-acrylic acid)

• Main Authors: Adeyi, Abel Adekanmi, Md. Jamil, Siti Nurul Ain, Abdullah, Luqman Chuah, Choong, Thomas Shean Yaw, Lau, Kia Li, Abdullah, Mohammad
• Format: Article
• Language: English
• Published: MDPI 2019
• Online Access: http://psasir.upm.edu.my/id/eprint/38362/1/38362.pdf; http://psasir.upm.edu.my/id/eprint/38362/; https://www.mdpi.com/1996-1944/12/11/1734

The paper evaluates the adsorptive potential of thiourea-modified poly(acrylonitrile-co-acrylic acid), (TA-poly(AN-co-AA)) for the uptake of cationic methylene blue (MB) from aquatic environments via a batch system. TA-poly(AN-co-AA) polymer was synthesized through redox polymerization and modified with thiourea (TA) where thioamide groups were introduced to the surface. Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), CHNS and Zetasizer were used to characterize the physico-chemical and morphological properties of prepared TA-poly(AN-co-AA). Afterwards, it was confirmed that incorporation of thioamide groups was successful. The adsorption kinetics and equilibrium adsorption data were best described, respectively, by a pseudo-second-order model and Freundlich model. Thermodynamic analysis showed the exothermic and spontaneous nature of MB uptake by TA-poly(AN-co-AA). The developed TA-poly(AN-co-AA) polymer demonstrated efficient separation of MB dye from the aqueous solution and maintained maximum adsorption capacity after five regeneration cycles. The findings of this study suggested that synthesized TA-poly(AN-co-AA) can be applied successfully to remove cationic dyes from aquatic environments.