Adsorptive Removal of Methylene Blue from Aquatic Environments Using Thiourea-Modified Poly(Acrylonitrile-co-Acrylic Acid)

Abstract

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.

Eco-Friendly Sustainable Fluorescent Carbon Dots for the Adsorption of Heavy Metal Ions in Aqueous Environment

“…It indicates the amount of lead (Pb 2+ ) adsorbed by the CDs and the residual lead in the bulk solution at room temperature [49]. The equilibrium isotherms were obtained graphically by plotting solid phase concentration against liquid phase concentration [50].…”

“…Langmuir forms can be correlated with the variation of the suitable area and porosity of the adsorbent. Availability of CDs at nano dimension level offers vast surface area and pore volume availability for pore diffusion-sorption activities [50] that results in a higher adsorption capacity [18].…”

“…The pseudo-second-order kinetic equation for adsorption is much similar to the universal rate law for chemical reaction [47]. Since the processes followed the pseudo second-order equation, it literally suggests that the adsorption is mainly by simple chemisorption reaction occurring between the lead ions and the surface functional groups of CDs [49,50].…”

Simultaneous Adsorption of Cationic Dyes from Binary Solutions by Thiourea-Modified Poly(acrylonitrile-co-acrylic acid): Detailed Isotherm and Kinetic Studies

“…Moreover, previous researches on dye adsorption were carried out explicitly in single dye systems and scanty study reports were available in binary dye systems. Our previous work reports in detail preparation and characterization of thiourea-modified poly(acrylonitrile- co -acrylic acid) (TMPAA) and its adsorption capacities towards MG and MB in a single dye system [20,21,22]. Generally, multiple components of dyes coexist in real industrial wastewater systems.…”

Polymer supports for the removal and degradation of hazardous organic pollutants: an overview

“…The same dye was then adsorbed onto acrylonitrile and acrylic acid copolymers and modified with thiourea, thus obtaining a 95% removal at pH 9 with a contact time of 60 min. In this case, the mechanism involved was attributed to the electrostatic interaction between the cationic dye and ionized carboxylic groups …”