Water Sanitization by the Elimination of Cd²⁺ Using Recycled PET/MWNT/LDH Composite: Morphology, Thermal, Kinetic, and Isotherm Studies

Abstract

The fabrication and characterization of recycled polyethylene terephthalate nanocomposites (R-PET NCs) reinforced with multiwalled carbon nanotubes/Mg–Al mixed metal oxides (MWNT/LDH) is reported in this study. The morphology images and X-ray diffraction indicated that the MWNT/LDH hybrids were mostly exfoliated in the R-PET matrix. The good dispersion of filler in the R-PET caused MWNT/LDH to operate as a gas barrier and slowed down the thermal degradation of the R-PET matrix. The prepared composite was further employed to eliminate Cd2+ from aqueous media. The influence of pH, contact time, coexist ions, temperature, and initial pollutant concentration on the sorption procedure was examined. The high removal efficiency was gained for the Cd2+ sorption by R-PET/MWNT/LDH NC 4 wt %. The sorption equilibria were well explained by both the Freundlich and Langmuir models. The adsorption kinetics of Cd2+ onto R-PET/MWNT/LDH NC 4 wt % could be well described by the pseudo-second-order model. The extracted E value from the Dubinin–Radushkevich equation and thermodynamic data proposed that the sorption was mainly physical. In addition, without the use of magnetic separation, prepared sorbent could be simply collected and reused.

Adsorptive removal of cadmium from aqueous solutions using NiFe2O4/hydroxyapatite/graphene quantum dots as a novel nano-adsorbent

“…Based on the pseudo-second order model, the chemical absorption is a limiting step, so reliable results suggest that the absorption behavior may be in the sharing of electrons or exchange between the Cd 2+ ions and NiFe 2 O 4 / HAP/GQDs. Similar findings have been reported for the absorption of Cd 2+ ions [46,47]. Therefore, the results from the interpretation of isotherms are consistent with the results of kinetics studies.…”

Adsorption of Methyl Orange from Aqueous Solution Using PVOH Composite Films Cross-Linked by Glutaraldehyde and Reinforced with Modified α-MnO2

“…E is the free energy of transferring 1 mol of MO to the adsorbent surface in solution (kJ mol –1 ) and is estimated using eq . Commonly, for the value of acquired E below 8 kJ mol –1 , the adsorption mechanism is physical. For values of E in the range of 8–16 kJ mol –1 , ion exchange has happened, and the adsorption mechanism is chemical in the range of 20–40 kJ mol –1 . − …”

Deposition of silicate coatings on poly(ethylene terephthalate) for improved scratch and solvent resistance

“…Examples of the latter include materials with enhanced mechanical/optical properties of PET through the addition of silicate clays, carbonaceous nanosized fillers, and metal oxides. 4,5,6,7,8,9 Creating a stable and functional coating on top of the PET is not a trivial task. A plethora of physical and chemical methods exist that enables the formation of functional coatings on top PET substrates.…”