12 research outputs found
Elastic-plastic secondary indeterminate problem for thin-walled pipe through the inner-wall loading by three-point bending
No full textKeggin‐type Heteropolyacids‐Catalyzed Selective Hydrothermal Oxidation of Microalgae for Low Nitrogen Biofuel Production
No full textGreen Synthesis of Magnetic EDTA- and/or DTPA-Cross-Linked Chitosan Adsorbents for Highly Efficient Removal of Metals
No full textThe present paper describes a green
and economic approach to explore
EDTA/DTPA-functionalized magnetic chitosan as adsorbents for the removal
of aqueous metal ions, such as Cd(II), Pb(II), Co(II), and Ni(II).
EDTA and DTPA play roles not only as cross-linkers but also as functional
groups in chelating metal ions. The morphology, structure, and property
of the magnetic adsorbents were characterized by SEM, TEM, XRD, EDS,
FT-IR, TGA, and VSM techniques. Their adsorption properties for the
removal of metal ions by varying experimental conditions were also
investigated. The kinetic results revealed that the transportation
of adsorbates from the bulk phase to the exterior surface of adsorbents
was the rate-controlling step. The obtained maximum adsorption capacities
of magnetic adsorbents for the metal ions ranged from 0.878 to 1.561
mmol g<sup>–1</sup>. Bi-Langmuir and Sips isotherm models fitting
well to the experimental data revealed the surface heterogeneity of
the adsorbents. More significantly, the resulting EDTA-/DTPA-cross-linked
magnetic chitosan adsorbents had selectivity to Cu, Pb, Zn, Fe, and
Ni from a practical industrial effluent. Furthermore, their good reusability
and convenient magnetic separation makes them viable alternatives
for real wastewater treatment
Green synthesis of citric acid-crosslinked β-cyclodextrin for highly efficient removal of uranium(VI) from aqueous solution
No full text
Kenaf cellulose-based poly(amidoxime) ligand for adsorption of rare earth ions
No full textA well-known adsorbent, poly(amidoxime) ligand, was prepared from polyacrylonitrile (PAN) grafted kenaf cellulose, and subsequent characterization was performed by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM) and inductively coupled plasma mass spectrometry (ICP-MS). The adsorption capacities of the prepared ligand for rare earth metals are found to be excellent, with adsorptions of La 3+ , Ce 3+ , Pr 3+ , Gd 3+ and Nd 3+ experimentally determined to be 262, 255, 244, 241 and 233 mg·g −1 , respectively, at pH 6. The experimental values of the adsorption of rare earth metals are well matched with the pseudo-second-order rate equation. The reusability of the adsorbent is examined for seven cycles of sorption/desorption, demonstrating that the proposed adsorbent could be reused for over seven cycles without any significant loss in the original removal capability of the ligand
