ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2025
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IF 0
Maqinana Siphosethu,Kowenje Chrispin B. O.,Ojwach Stephen O.
Reactions of N 1 ,N 3 -bis(2-mercaptoethyl)isophthalamide with (3-aminopropyl)triethoxysilane (3-APTES) afforded the the corresponding Schiff base chelating ligand, (1Z,3Z)-N 1 ,N 3 -bis(2-mercaptoethyl)-N' 1 ,N' 3 bis(3(triethoxysilyl)propyl) isophthalimidamide ( L1 ) in high yields. Subsequent immobilization of L1 on mesoporous silica supports (SBA-15 and MCM-41) following a divergent method produced the respective fabricated L1@SBA-15 and L1@MCM-41 materials. Characterization of the fabricated chelating agents was accomplished using SEM, TEM, EDX, BET, PXRD, FT-IR, and TGA-DTA/DSC techniques. The fabricated materials were used as adsorbents for the removal of Cd(II), Pb(II) and Cr(VI) metal ions from water. Both the L1@SBA-15 and L1@MCM-41 materials demonstrated high extraction efficiencies for Cd(II) and Pb(II) cations, achieving over 98% and 97% removal, respectively, across a broad pH range (3–9). For Cr(VI) anions, relatively lower optimal extraction efficiencies of 67% and 77% were recorded between pH 3–12, for L1@SBA-15 and L1@MCM-41 , adsorbents, respectively. Faster extraction kinetics were observed for Cd(II) and Pb(II) cations, with over 94% removal achieved within 30 min, even at low initial metal concentrations (5 ppm) and adsorbent dosages (10 mg). Kinetic modelling showed that the adsorption process followed a pseudo -second-order kinetics, with high correlation coefficients (R 2 ) for Cd(II), Pb(II), and Cr(VI) of 0.97573, 0.97348, and 0.91017 using L1@MCM-41 , and 0.9754, 0.97089, and 0.89411 using L1@SBA-15 , respectively. Equilibrium data best fitted the Freundlich isotherm model, with R 2 values of 0.97952, 0.99892, and 0.97374 for L1@SBA-15 and 0.99879, 0.99999, and 0.90923 for L1@MCM-41 , corresponding to Cd(II), Pb(II), and Cr(VI), respectively. In competitive metal ion systems, the extraction selectivity followed the order Cd(II) > Pb(II) > Cr(VI), with L1@SBA-15 exhibiting superior overall performance compared to L1@MCM-41 . The extraction mechanism was postulated to occur through the coordination of the metal ions to the nitrogen/sulfur donor atoms in the chelating agents, consistent with the hard and soft acid and base (HSAB) principle. Furthermore, L1@MCM-41 demonstrated notable regeneration potential, retaining Cr(VI) extraction efficiencies over four successive cycles. Graphical
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DOI
PubMed
Sustainable Chemistry and Pharmacy
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2023
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IF 6
Jiahuan Xu,Lijin Peng,Jianbo Chu,Jing Shi,Qinmin Cui,Qiyuan Shi
This work aims to resolve the environmental pollution caused by petroleum ether in the production of pure nuciferine from lotus leaf by applying bio-based solvent (D-limonene) and green solvent (ethyl acetate). Some obvious advantages were observed, over 97% of nuciferine could be extracted by vortex assisted two-phase solvent extraction based on multi-stage strategy (MS-VTSE), over 90% of nuciferine could be recovered by solid phase extraction (SPE), and over 97% of nuciferine could be obtained by pH-dependent liquid-liquid extraction (pH-LLE). It follows that the newly developed method can not only avoid the use of petroleum ether, but also increase the yield of the whole process by 14% (57%) in comparing with the result of the original one (50%) reported in our previous study. As D-limonene could by recycled conveniently, solvents replacement has little effect on the cost of production. In a word, the newly proposed method has advantages in environmental protection and solvent saving, thus, is fitting for the green and low-cost production of pure nuciferine from lotus leaf.
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DOI
高影响因子
LANGMUIR
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2024
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IF 3.7
Jiawei Liu,Guo Du,Tiehong Chen
Ordered mesoporous silica is widely used in catalysis, adsorption, and biomedicine, among which SBA-15 (Santa Barbara Amorphous-15) is one of the most widely studied. However, the synthesis of SBA-15 often requires strong acid (hydrochloric acid or sulfuric acid), which will not only corrode industrial equipment but also pollute the environment with the wastewater containing strong acid and halogen (sulfur). Here, we demonstrate a green synthetic strategy for SBA-15 under weakly acidic conditions through an anionic assembly route. With the assistance of poly(acrylic acid) (PAA) and 3-aminopropyltrimethoxysilane (APMS), the pH value of the synthesis system can be increased to 4–5, which is a mild near-neutral condition. In addition, halogen-free synthesis using organic acids is also achieved. The powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and N2 sorption characterizations show that the obtained SBA-15 has good texture properties, with a specific surface area of 430–500 m2/g and ordered 6–8 nm mesopores, which is similar to SBA-15 synthesized in traditional strong acid. This strategy provides a facile and environmentally friendly route for the large-scale production of ordered mesoporous materials.
研究领域:
材料科学
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化学
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环境科学
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DOI
高影响因子