ABSTRACT
Uranium as a strategic and non-renewable resource has been paid close attention to its efficient recovery and reuse from uranium-containing wastewater. Here, a composite bead was prepared by functionalized graphene oxide and sodium alginate (L-Lys-GO/SA) with ion-stimuli responsiveness for achieving U(VI) adsorption. The L-Lys-GO/SA-60 composite beads can selectively adsorb U(VI) with the maximum adsorption capacity (qmax) of 704.22 mg/g. Interestingly, the composite beads will swell under the stimulation of ions, which is more conducive to rapid solid-liquid separation and U(VI) recovery at low energy consumption. More importantly, the composite beads also exhibit high reusability of U(VI) adsorption with excellent life span of 80.11 % adsorption rate after 9 cycles, meaning that the composite beads and technology may be used in extraction and production for U(VI) from uranium-containing wastewater.
Subject(s)
Uranium , Alginates , Wastewater , Adsorption , Ions , KineticsABSTRACT
Graphene oxide (GO) and its composite membranes have exhibited great potential for application in water purification and desalination. This article reports that a novel graphene oxide membrane (GOM) of ~5 µm thickness was fabricated onto a nylon membrane by vacuum filtration and cross-linked by amino acids (L-alanine, L-phenylalanine, and serine). The GOM cross-linked by amino acids (GOM-A) exhibits excellent stability, high water flux, and high rejection to metal ions. The rejection coefficients to alkali and alkaline earth metal ions through GOM-A were over 94% and 96%, respectively. The rejection coefficients decreased with an increasing H+ concentration. Metal ions (K+, Ca2+, and Fe3+) can be inserted into GOM-A layers, which enlarges the interlayer spacing of GOM-A and neutralizes the electronegativity of the membrane, resulting in the decease in the rejection coefficients to metal ions. Meanwhile, GOM-A showed quite high antibacterial efficiency against E. coli. With the excellent performance as described above, GOM-A could be used to purify and desalt water.
ABSTRACT
A new boron-dipyrromethene (BODIPY) fluorescent dye aimed at sensitively detecting hypochlorite anion (ClO-) has been designed, synthesized and characterized. The probe is comprised of a BODIPY fluorophore unit and a ClO- specific reactive group of amidoxime. The addition of hypochlorite results in a red-shift of absorption and emission spectra of the probe accompanied by a decrease of intensity and spectra changes (A500 and 1/I512) of the probe can achieve a good linearity to the concentration of ClO-. The fluorescence probe can react to ClO- rapidly (within 60 s) in a wide pH range (4-10) with high sensitivity (detection limit of 6.81 µM) and selectivity. The reaction mechanism has been proposed and confirmed by MS analysis, ClO- anion oxidizes amidoxime moiety to hydroxyl group and hydroxyl group is further oxidized to formyl group in the formation of a corresponding aldehyde compound. In addition, the probe has also been successfully applied to detect ClO- in tap water and river water samples by spiking a known amount of standard ClO-.
ABSTRACT
Six new sesquiterpene lactones, scorzoaustriacoside (1), scorzoaustriacin (2), scorzoaustriacin 3-O-beta-d-glucoside (3), 4-epi-dihydroestafiatol (4), 14-isovaleroxyscorzoaustricin (5), and 14-isovaleroxyscorzoaustricin sulfate (6), along with five known guaianolides, were isolated from an acetone extract of the roots of Scorzonera austriaca. The structures of the new compounds were elucidated mainly by interpretation of their 1D and 2D NMR and HRMS data. Several isolates obtained in this investigation were evaluated against a small panel of cancer cell lines.
