Preparation, Characterization, and Application of Polyacrylamide‐Polystyrene/Bentonite Nanocomposite as an Effective Immobilizing Adsorbent for Remediation of Soil

Abstract

Heavy metals are among the most important environmental pollutants. However, little attention has been devoted to immobilizing or fixing metal ions in soil for remediation of soil. Here, a novel and inexpensive, polymer nanocomposite (polyacrylamide-polystyrene/bentonite) is introduced for successful immobilization of cadmium (Cd) and lead (Pb) cations in the soil. The synthesized nanocomposite structure was characterized by X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy/Energy-Dispersive X-Ray Spectroscopy (FE-SEM/EDX), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET), and Fourier-Transform Infrared Spectroscopy (FT-IR). Various effective parameters such as pH, bentonite: polyacrylamide weight ratio, heavy metal concen-tration, and amount of adsorbent were investigated for fixing Pb and Cd cations in farm soil. Also, adsorption isotherms and kinetics of adsorption were investigated. Finally, under optimum conditions, the extent of adsorption of Pb and Cd cations by polyacrylamide-polystyrene/bentonite nanocomposite, polyacrylamide, and bentonite was compared. The results revealed the superior adsorption activity of the nanocomposite for immobilizing heavy metal cations as compared to bentonite or polymer. Further, the nanocomposite indicated a reasonable reusability for fixing Cd and Pb cations. Overall, the prepared nanocomposite can be applied as a suitable and industrial adsorbent for immobilizing Pb and Cd cations in soil.

Preparation of humic acid-bentonite polymer composite: A heavy metal ion adsorbent

“…Generally, it is expected that competition between H 2 O 3 M 2+ ions reduce adsorption capacity at a low pH, [ 37 ], therefore in the higher acidic regions, preferably at pH values ranging from 4-7 most adsorbents perform better in comparison to their performances in lower acidic regions. As the adsorption extent is withered in lower acidic regions, increasing pH thereby increases adsorption, and this is one of the dependent variables in adsorption affecting the efficiency of many adsorbents.…”

“…[ 37 ], prepared a Polyacrylamide-polystyrene/Bentonite nanocomposite for immobilizing Cd 2+ and Pb 2+ ions in the soil, and in this study, he discusses the adsorption efficiency of the nanocomposite in comparison to polyacrylamide or bentonite alone, which was found to be quite better, hereby signifying the presence of multiple material properties in a single adsorbent resulting in enhanced adsorption capacity [ 37 ]. Their results showed that the adsorption of Cd 2+ and Pb 2+ ions by bentonite occurs happens via cation exchange, and even though the base exchange ability of bentonite is limited, there is again adsorption of these metal ions by the polymer which takes place via the interactions existing between the Oxygen and Nitrogen functional groups of the polymer and adsorbate ion [ 37 ]. Again, these however, these relations plus those of bentonite maybe and or are limited, and could not possibly aid a successful removal of Cd 2+ and Pb 2+ ions from the sorbate, hence the room for innovation of such composites to improve their selectivity and adsorption properties.…”

“…Again, these however, these relations plus those of bentonite maybe and or are limited, and could not possibly aid a successful removal of Cd 2+ and Pb 2+ ions from the sorbate, hence the room for innovation of such composites to improve their selectivity and adsorption properties. The distinct polyacrylamide-polystyrene/bentonite nanocomposite properties are the fact that it is able to enjoys both the ion exchange abilities of bentonite and the interactivity between N and O groups of the polymer and the cations [ 37 ], therefore the scope of adsorption by the nanocomposite was substantially higher.…”

Deproteinized natural rubber‐graft‐polyacrylamide‐graft‐polystyrene (DPNR‐g‐PAM‐g‐PSt): Preparation and performance study of a new water swellable rubber

“…38 The addition of Acrylamide (AM) significantly improves the water absorption of the product, its own thermal stability and salt resistance is also improved. [39][40][41][42] Bentonite is used in the following fields: (1) Bentonite mud can be used as drilling fluid. The addition of bentonite to concrete can significantly improve the durability, compressive strength, and corrosion resistance of concrete.…”

“…St is easy to prepare, low cost, hard and brittle, and through grafting, toughens NR while improving its own brittleness 38 . The addition of Acrylamide (AM) significantly improves the water absorption of the product, its own thermal stability and salt resistance is also improved 39–42 . Bentonite is used in the following fields: (1) Bentonite mud can be used as drilling fluid.…”