The Algerian kaolin clay was investigated to remove Zn(II) heavy metal ion from aqueous solution. The effect of contact time, initial metal ion concentration, pH and temperature was experimentally studied in batch mod...The Algerian kaolin clay was investigated to remove Zn(II) heavy metal ion from aqueous solution. The effect of contact time, initial metal ion concentration, pH and temperature was experimentally studied in batch mode to evaluate the adsorption capacity, kinetic, thermodynamic and equilibrium. The extent of zinc adsorption increased with increasing initial concentration of adsorbat, pH and temperature. The linear Langmuir and Freundlich models were applied to describe equilibrium isotherms and both models fitted well. The monolayer adsorption capacity for Zn(II) ions was 12.23 mg per g of kaolin clay at pH 6.1 and 25°C. Dubinin-Radushkevich (D-R) isotherm model was also applied to the equilibrium data. Thermodynamic parameters showed that the adsorption of Zn(II) onto kaolin clay was spontaneous and endothermic process in nature. Furthermore, the Lagergren-first-order and pseudo-second-order models were used to describe the kinetic data. The experimental data fitted well the pseudo-second-order kinetic. As a result, the kaolin clay may be used for removal of zinc from aqueous media.展开更多
Among the various possibilities of limiting the disposal of fly ashes (lignite), their reutilization as adsorbent materials is worthy of consideration. To this end, proper ashes beneficiation techniques can be put int...Among the various possibilities of limiting the disposal of fly ashes (lignite), their reutilization as adsorbent materials is worthy of consideration. To this end, proper ashes beneficiation techniques can be put into practice. The adsorption of toxic compounds from industrial wastewater is an effective method for both treating these effluents and recycling lignite fly ash. The aim of this paper is to give a contribution for understanding the relationships among beneficiation treatments, adsorbent properties and adsorption mechanism and efficiency. In this context, the lignite fly ash was demineralised using concentrated HCl and HF (FA-DEM) and was used as adsorbent for Zn(II) ions from aqueous solutions. Batch experiments were carried out under various adsorbent dosages, pH, contact time and different metal ion concentrations. For FA-DEM, the 57.7% removal of Zn(II) ion was achieved under the optimum conditions of adsorbent dosages of 4 g/L, pH at 6, temperature at 303 K and the contact time of 1.15 h. The adsorption of Zn(II) ions onto FA-DEM followed the pseudo second order kinetics. The Langmuir isotherm model best represented the equilibrium data.展开更多
The title compound [Zn(Him2Py)(N3)2]2 (Zn2C26H38N18O2, Mr = 765.48) has been prepared and structurally characterized by X-ray diffraction methods. It crystallizes in monoclinic, space group P21/n with a = 10.989(3), b...The title compound [Zn(Him2Py)(N3)2]2 (Zn2C26H38N18O2, Mr = 765.48) has been prepared and structurally characterized by X-ray diffraction methods. It crystallizes in monoclinic, space group P21/n with a = 10.989(3), b = 11.519(3), c = 13.812(4) ? b = 101.700(5), V = 1711.9(9) ?, Z = 2, Dc = 1.485 g/cm3, m(MoKa) = 1.456 mm～1, F(000) = 792, the final R = 0.0401 and wR = 0.0861 for 2054 observed reflections with I>2s(I). The imino nitroxide 2-(3- methyl-2-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl (im2Py) was reduced to obtain 2-(3-methyl -2-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-ydroxy (Him2Py) coordinating to the zinc (II) ion, around which the coordination geometry is a square-based pyramid with a terminal nitrogen atom located at the apical position. The four basal sites are occupied by two m1,1 nitrogen atoms from two different bridging azide ions and two nitrogen atoms from Him2Py. The units of [Zn(Him2Py)(N3)2]2 were connected as two dimension planes by intermolecular hydrogen bonds.展开更多
Zinc (Zn (II) HEDTA) was used to determine their effect on salt-induced damages in maize plants. The aim of this study was to investigate the antioxidant capacity and the levels of enhanced total phenolic (TPC), total...Zinc (Zn (II) HEDTA) was used to determine their effect on salt-induced damages in maize plants. The aim of this study was to investigate the antioxidant capacity and the levels of enhanced total phenolic (TPC), total flavonoid (TFC) contents and their antioxidant activity in leaves of two maize cultivars Single cross 10 (SC10) and Single cross 162 (SC162) grown in two levels of salinity 0.00 and 100 mmol in response to 20 μmol Zn (II) HEDTA foliar spray treatments. Significant differences (P ≤ 0.05) in amounts of TPC ranged from (2.55 to 4.62 mg/gdw as Gallic) in Single cross 10 (SC10) and from (2.53 to 4.38 mg/gdw as Gallic) in Single cross 162 (SC162), TFC (ranged 1.53 to 2.41 mg/gdw as qurestien) in Single cross 10 (SC10) and from (1.28 to 2.41 mg/gdw as qurestien) in Single cross 162 (SC162) among all treated plants were observed. The levels of their compounds increase related to foliar spraying of Zn (II) HEDTA. A significant positive correlation between TPC, TFC and DPPH scavenging activity and iron chelating activity was observed which shows that phenolic compounds were involved in the mechanism of salt tolerance of the two cultivars by showing enhanced antioxidant activity which resulted in reduced membrane damage and hence improved growth. According to the results obtained, the adverse effects of salt stress on maize plants can partly be alleviated with application of Zn (II)-HEDTA chelates. It is concluded that the application of Zn (II) HEDTA to maize plants grown in salt conditions leads to the increase of antioxidant compounds and maize tolerance.展开更多
There are many reports that divalent alkaline earth, first-row transition metals, and Zn(II) ions have α-glucosidase inhibitory effects. Cu(II) and Zn(II) ions, in particular, have strong α-glucosidase inhibitory ef...There are many reports that divalent alkaline earth, first-row transition metals, and Zn(II) ions have α-glucosidase inhibitory effects. Cu(II) and Zn(II) ions, in particular, have strong α-glucosidase inhibitory effects. Several Schiff bases also display α-glucosidase inhibitory effects. In this study, we focused on safe and highly effective complexes including Zn(II) ion. We prepared and characterized the Zn(II) complexes with four different Schiff bases (N-salicylidene-β-alanine (N-sβ), N-N’-bis (salicylidene) ethylenediamine (N-bsE), N, N’-bis (salicylidene)-phenylenediamine (N-bsP), and 1-[(2-dimethylaminoethylimino) methyl]naphtholate (DMN)) and investigated their α-glucosidase inhibitory effects in vitro, using α-glycosidases from Saccharomyces sp. and rat small intestine, and in vivo, using a sucrose tolerance test. The Zn(II) complexes with DMN showed the highest in vitro and in vivo α-glucosidase inhibitory effects in this study.展开更多
A new mixed complex [Zn(tren) (H-SSA)] was synthesized based on the reaction of ZnO,5-sulfosalicylic acid and tren in water-methanol mixed solvents where tren was tris(2-aminoethyl)amine for the first time. The struct...A new mixed complex [Zn(tren) (H-SSA)] was synthesized based on the reaction of ZnO,5-sulfosalicylic acid and tren in water-methanol mixed solvents where tren was tris(2-aminoethyl)amine for the first time. The structure of the mixed complex was characterized by elemental analysis, IR, 1H NMR and thermal analysis. The crystal structure of the complex was also determined by X-ray single crystal diffraction. Its crystal belongs to trigonal system with space group P31, a=1.109 67(18) nm, b=1.109 67(18) nm, c=1.236 8(4) nm, V=1.318 9(5) nm3; Dc=1.616 g·cm-3; Z=3; F(000)=666; μ=1.553 mm-1. CCDC: 253908.展开更多
文摘The Algerian kaolin clay was investigated to remove Zn(II) heavy metal ion from aqueous solution. The effect of contact time, initial metal ion concentration, pH and temperature was experimentally studied in batch mode to evaluate the adsorption capacity, kinetic, thermodynamic and equilibrium. The extent of zinc adsorption increased with increasing initial concentration of adsorbat, pH and temperature. The linear Langmuir and Freundlich models were applied to describe equilibrium isotherms and both models fitted well. The monolayer adsorption capacity for Zn(II) ions was 12.23 mg per g of kaolin clay at pH 6.1 and 25°C. Dubinin-Radushkevich (D-R) isotherm model was also applied to the equilibrium data. Thermodynamic parameters showed that the adsorption of Zn(II) onto kaolin clay was spontaneous and endothermic process in nature. Furthermore, the Lagergren-first-order and pseudo-second-order models were used to describe the kinetic data. The experimental data fitted well the pseudo-second-order kinetic. As a result, the kaolin clay may be used for removal of zinc from aqueous media.
文摘Among the various possibilities of limiting the disposal of fly ashes (lignite), their reutilization as adsorbent materials is worthy of consideration. To this end, proper ashes beneficiation techniques can be put into practice. The adsorption of toxic compounds from industrial wastewater is an effective method for both treating these effluents and recycling lignite fly ash. The aim of this paper is to give a contribution for understanding the relationships among beneficiation treatments, adsorbent properties and adsorption mechanism and efficiency. In this context, the lignite fly ash was demineralised using concentrated HCl and HF (FA-DEM) and was used as adsorbent for Zn(II) ions from aqueous solutions. Batch experiments were carried out under various adsorbent dosages, pH, contact time and different metal ion concentrations. For FA-DEM, the 57.7% removal of Zn(II) ion was achieved under the optimum conditions of adsorbent dosages of 4 g/L, pH at 6, temperature at 303 K and the contact time of 1.15 h. The adsorption of Zn(II) ions onto FA-DEM followed the pseudo second order kinetics. The Langmuir isotherm model best represented the equilibrium data.
基金This work was supported by the National Natural Science Foundation of China (No. 20171025 and No. 90101028)
文摘The title compound [Zn(Him2Py)(N3)2]2 (Zn2C26H38N18O2, Mr = 765.48) has been prepared and structurally characterized by X-ray diffraction methods. It crystallizes in monoclinic, space group P21/n with a = 10.989(3), b = 11.519(3), c = 13.812(4) ? b = 101.700(5), V = 1711.9(9) ?, Z = 2, Dc = 1.485 g/cm3, m(MoKa) = 1.456 mm～1, F(000) = 792, the final R = 0.0401 and wR = 0.0861 for 2054 observed reflections with I>2s(I). The imino nitroxide 2-(3- methyl-2-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl (im2Py) was reduced to obtain 2-(3-methyl -2-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-ydroxy (Him2Py) coordinating to the zinc (II) ion, around which the coordination geometry is a square-based pyramid with a terminal nitrogen atom located at the apical position. The four basal sites are occupied by two m1,1 nitrogen atoms from two different bridging azide ions and two nitrogen atoms from Him2Py. The units of [Zn(Him2Py)(N3)2]2 were connected as two dimension planes by intermolecular hydrogen bonds.
文摘Zinc (Zn (II) HEDTA) was used to determine their effect on salt-induced damages in maize plants. The aim of this study was to investigate the antioxidant capacity and the levels of enhanced total phenolic (TPC), total flavonoid (TFC) contents and their antioxidant activity in leaves of two maize cultivars Single cross 10 (SC10) and Single cross 162 (SC162) grown in two levels of salinity 0.00 and 100 mmol in response to 20 μmol Zn (II) HEDTA foliar spray treatments. Significant differences (P ≤ 0.05) in amounts of TPC ranged from (2.55 to 4.62 mg/gdw as Gallic) in Single cross 10 (SC10) and from (2.53 to 4.38 mg/gdw as Gallic) in Single cross 162 (SC162), TFC (ranged 1.53 to 2.41 mg/gdw as qurestien) in Single cross 10 (SC10) and from (1.28 to 2.41 mg/gdw as qurestien) in Single cross 162 (SC162) among all treated plants were observed. The levels of their compounds increase related to foliar spraying of Zn (II) HEDTA. A significant positive correlation between TPC, TFC and DPPH scavenging activity and iron chelating activity was observed which shows that phenolic compounds were involved in the mechanism of salt tolerance of the two cultivars by showing enhanced antioxidant activity which resulted in reduced membrane damage and hence improved growth. According to the results obtained, the adverse effects of salt stress on maize plants can partly be alleviated with application of Zn (II)-HEDTA chelates. It is concluded that the application of Zn (II) HEDTA to maize plants grown in salt conditions leads to the increase of antioxidant compounds and maize tolerance.
文摘There are many reports that divalent alkaline earth, first-row transition metals, and Zn(II) ions have α-glucosidase inhibitory effects. Cu(II) and Zn(II) ions, in particular, have strong α-glucosidase inhibitory effects. Several Schiff bases also display α-glucosidase inhibitory effects. In this study, we focused on safe and highly effective complexes including Zn(II) ion. We prepared and characterized the Zn(II) complexes with four different Schiff bases (N-salicylidene-β-alanine (N-sβ), N-N’-bis (salicylidene) ethylenediamine (N-bsE), N, N’-bis (salicylidene)-phenylenediamine (N-bsP), and 1-[(2-dimethylaminoethylimino) methyl]naphtholate (DMN)) and investigated their α-glucosidase inhibitory effects in vitro, using α-glycosidases from Saccharomyces sp. and rat small intestine, and in vivo, using a sucrose tolerance test. The Zn(II) complexes with DMN showed the highest in vitro and in vivo α-glucosidase inhibitory effects in this study.
文摘A new mixed complex [Zn(tren) (H-SSA)] was synthesized based on the reaction of ZnO,5-sulfosalicylic acid and tren in water-methanol mixed solvents where tren was tris(2-aminoethyl)amine for the first time. The structure of the mixed complex was characterized by elemental analysis, IR, 1H NMR and thermal analysis. The crystal structure of the complex was also determined by X-ray single crystal diffraction. Its crystal belongs to trigonal system with space group P31, a=1.109 67(18) nm, b=1.109 67(18) nm, c=1.236 8(4) nm, V=1.318 9(5) nm3; Dc=1.616 g·cm-3; Z=3; F(000)=666; μ=1.553 mm-1. CCDC: 253908.
