RESUMO
Magnetic chitosan/cellulose nanofiber-Fe(III) [M-Ch/CNF-Fe(III)] composites were isolated for the elimination of Cr(VI), Cu(II), and Pb(II) from aqueous solution. Various analytical methods, such as field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), and thermogravimetric analysis (TGA) were employed to determine the morphological, physicochemical, and thermal properties of the isolated M-Ch/CNF-Fe(III) composites. It was found that the M-Ch/CNF-Fe(III) composites were porous materials, and they have the potential to be implemented as an adsorbent for heavy metals removal. The adsorption efficiency of M-Ch/CNF-Fe(III) composites was determined for Cr(VI), Cu(II), and Pb(II) elimination with changing pH (pH 1.0-8.0), adsorbent doses (0.05-1.0 g), time (15-90 min), and temperature (28-80 °C). In addition, isothermal and kinetics studies were conducted to assess the adsorption behavior and mass transfer phenomena of M-Ch/CNF-Fe(III) composites as an adsorbent for Cr(VI), Cu(II) and Pb(II) elimination from aqueous solution. The outcomes of the present study reveal that the M-Ch/CNF-Fe(III) composites could be utilized as an adsorbent for the Cr(VI), Cu(II), and Pb(II) elimination from industrial effluents.
RESUMO
In the present study, magnetic oil palm empty fruits bunch cellulose nanofiber (M-OPEFB-CNF) composite was isolated by sol-gel method using cellulose nanofiber (CNF) obtained from oil palm empty fruits bunch (OPEFB) and Fe3O4 as magnetite. Several analytical methods were utilized to characterize the mechanical, chemical, thermal, and morphological properties of the isolated CNF and M-OPEFB-CNF. Subsequently, the isolated M-OPEFB-CNF composite was utilized for the adsorption of Cr(VI) and Cu(II) from aqueous solution with varying parameters, such as pH, adsorbent doses, treatment time, and temperature. Results showed that the M-OPEFB-CNF as an effective bio-sorbent for the removal of Cu(II) and Cr(VI) from aqueous solution. The adsorption isotherm modeling revealed that the Freundlich equation better describes the adsorption of Cu(II) and Cr(VI) on M-OPEFB-CNF composite. The kinetics studies revealed the pseudo-second-order kinetics model was a better-described kinetics model for the removal of Cu(II) and Cr(VI) using M-OPEFB-CNF composite as bio-sorbent. The findings of the present study showed that the M-OPEFB-CNF composite has the potential to be utilized as a bio-sorbent for heavy metals removal.
RESUMO
Moringa oleifera Lam. and Centella asiatica (L.) Urb. leaves have been previously reported to exhibit antioxidant activity. The objective of the present study is to determine the in vitro antioxidant activity of the combined extracts of M. oleifera and C. asiatica (TGT-PRIMAAGE) and its effect on hydrogen peroxide (H 2O2)-induced oxidative stress in human dermal fibroblasts. TGTPRIMAAGE acted on the mechanism of hydrogen transfer as it showed scavenging activity in the DPPH assay. This is due to the presence of phenolics and flavonoids in TGT-PRIMAAGE. TGT-PRIMAAGE effectively reduced cellular generation of reactive oxygen species induced by H O2. The activities of superoxide dismutase and catalase were also increased in cells treated with TGT-PRIMAAGE. 2 Treatment with TGT-PRIMAAGE showed significant reduction (P < 0.05) in the number of senescent cells. Significant reduction (P < 0.05) of malondialdehyde was also seen in cells treated with TGT-PRIMAAGE. The p53 protein level was reduced in TGT-PRIMAAGEtreated cells, which indicates its potential in protecting the cells from oxidative stress induced by H2O2.
