Adsorption Behaviour of Ethylene Vinyl Acetate and Polycaprolactone-Bentonite Composites for Pb2+ Uptake

Abstract

The results presented in this work show that the hydrophobic thermoplastics, namely ethylene vinyl acetate (EVA) and polycaprolactone (PCL), could be good matrices for the synthesis of polymer/bentonite composites via the melt-blending method for the removal of heavy metals from water. The hydrophobic nature of the polymers was countered by using dry Na 2 SO 4 to form large free-volume pores. These pores, formed after the removal of the Na 2 SO 4 by washing, improved the contact ratio between bentonite particles and Pb 2? ions. The composites were able to achieve up to 78% Pb 2? removal at an initial concentration of 200 mg/L in 10 h with a clay loading of 3% (w/w). The results confirmed that the PCL/bentonite composite was more effective and efficient in the adsorption of Pb 2? than the EVA/bentonite composite. The experimental data for both composites followed Langmuir and Freundlich models. The uptake of Pb 2? was found to be a result of a chemical interaction between the heavy metal, silanol (Si-OH) and aluminol (Al-OH) groups. The adsorption of Pb 2? onto the composites was found to follow pseudo-first-order kinetics and the results supported a monomolecular reaction mechanism.

ANN modeling in Pb(II) removal from water by clay‐polymer composites fabricated via the melt‐blending

“…This observation can be ascribed to the disappearance of free Pb(II) ions in the solution due to interaction with the hydroxyl groups. The optimum pH for the adsorption of Pb(II) occurs at pH 5.5 …”

“…The composite strips were soaked in 1000 ml of deionized water for 24 h with vigorous stirring to remove leachable Na + and SO 4 2− ions. The physical properties of these composites were reported and discussed in our previously published work …”

“…To enlarge the quantity of data to satisfy the ANN creation and configuration, the Pb(II) adsorption data collected using C20A‐EVA, MD‐EVA, and MD‐PCL as adsorbents were used.…”

“…Every research study on the adsorption of Pb(II) from aqueous environments is generally targeted at producing chemically and thermally stable adsorbents, reproducible adsorbents, and high adsorption efficiency. These ambitious research projects have seen the introduction of polymer composites for use in water treatment …”

Controllable preparation and heavy‐metal‐ion adsorption of lignosulfonate‐polypyrrole composite nanosorbent

“…The cycling of lead in aquatic environment is attributed to their binding or adsorption to the surfaces of solid phases and complexation with the ligands in water. Several adsorbents have been studied for Pb(II) ions adsorption include chitosan , polycaprolactone‐bentonite composite , carbon nanotubes and graphene oxide , poly(phenylenediamine) , and polyaniline and its copolymers . Because nanomaterials exhibit enhanced reactivity, higher surface area and efficiency, many researches are launching to obtain inexpensive and more easily available nanosorbents with outstanding adsorptivity for Ag(I) and Pb(II) ions.…”