Lead (Pb) chemical fixation is an important environmental aspect for human health. Phosphate rocks (PRs) were utilized as an adsorbent to remove Pb from aqueous solution. Raw PRs and oxalic acid-activated PRs (A...Lead (Pb) chemical fixation is an important environmental aspect for human health. Phosphate rocks (PRs) were utilized as an adsorbent to remove Pb from aqueous solution. Raw PRs and oxalic acid-activated PRs (APRs) were used to investigate the effect of chemical modification on the Pb-binding capacity in the pH range 2.0-5.0. The Pb adsorption rate of all treatments above pH 3.0 reached 90%. The Pb binding on PRs and APRs was pH-independent, except at pH 2.0 in activated treatments. The X-ray diffraction analysis confirmed that the raw PRs formed cerussite after reacting with the Pb solution, whereas the APRs formed pyromorphite. The Fourier Transform Infrared spectroscopy analysis indicated that carbonate (CO32-) in raw PRs and phosphate (PO43-) groups in APRs played an important role in the Pb-binding process. After adsorption, anomalous block-shaped particles were observed by scanning electron microscopy with energy dispersive spectroscopy. The X-ray photoelectron spectroscopy data further indicated that both chemical and physical reactions occurred during the adsorption process according to the binding energy. Because of lower solubility of pyromorphite compared to cerussite, the APRs are more effective in immobilizing Pb than that of PRs.展开更多
In this study,hierarchical Ag/La2 O2 CO3 micro/nanostructures(MNSs)were synthesized by in situ loading Ag nanoparticles(NPs)on the surface of the La2 O2 CO3 MNSs.The prepared La2 O2 CO3 MNSs present flower-like shape ...In this study,hierarchical Ag/La2 O2 CO3 micro/nanostructures(MNSs)were synthesized by in situ loading Ag nanoparticles(NPs)on the surface of the La2 O2 CO3 MNSs.The prepared La2 O2 CO3 MNSs present flower-like shape and can be tuned by the molar ratio of La(NO3)3 and CO(NH2)2.In the molar ratio of 1:2 to 1:55,the La2 O2 CO3 MNSs mainly consist of polyhedral rods,irregular rods and irregular spindles and their size is about 10,8 and 7μm,respectively.After loading Ag NPs,the spindle-like Ag/La2 O2 CO3 MNSs were used for phosphate removal and antibacterial activity.At the initial phosphate concentration of20 mg/L,the removal rate is 59.6%.The Ag/La2 O2 CO3 MNSs have significant antibacterial activity and their MIC values for S.aureus and E.coli are 31.3 and 15.6μg/mL,respectively.The results indicate that Ag/La2 O2 CO3 MNSs may have good application prospects in open water to inhibit bacterial growth.展开更多
基金supported by the National Natural Science Foundation of China (No. 41071165)the Special Research Fund for the Doctoral Program of Higher Education, Ministry of Education (No. 20090146110003)
文摘Lead (Pb) chemical fixation is an important environmental aspect for human health. Phosphate rocks (PRs) were utilized as an adsorbent to remove Pb from aqueous solution. Raw PRs and oxalic acid-activated PRs (APRs) were used to investigate the effect of chemical modification on the Pb-binding capacity in the pH range 2.0-5.0. The Pb adsorption rate of all treatments above pH 3.0 reached 90%. The Pb binding on PRs and APRs was pH-independent, except at pH 2.0 in activated treatments. The X-ray diffraction analysis confirmed that the raw PRs formed cerussite after reacting with the Pb solution, whereas the APRs formed pyromorphite. The Fourier Transform Infrared spectroscopy analysis indicated that carbonate (CO32-) in raw PRs and phosphate (PO43-) groups in APRs played an important role in the Pb-binding process. After adsorption, anomalous block-shaped particles were observed by scanning electron microscopy with energy dispersive spectroscopy. The X-ray photoelectron spectroscopy data further indicated that both chemical and physical reactions occurred during the adsorption process according to the binding energy. Because of lower solubility of pyromorphite compared to cerussite, the APRs are more effective in immobilizing Pb than that of PRs.
基金Project supported by the National Natural Science Foundation of China(21271062)。
文摘In this study,hierarchical Ag/La2 O2 CO3 micro/nanostructures(MNSs)were synthesized by in situ loading Ag nanoparticles(NPs)on the surface of the La2 O2 CO3 MNSs.The prepared La2 O2 CO3 MNSs present flower-like shape and can be tuned by the molar ratio of La(NO3)3 and CO(NH2)2.In the molar ratio of 1:2 to 1:55,the La2 O2 CO3 MNSs mainly consist of polyhedral rods,irregular rods and irregular spindles and their size is about 10,8 and 7μm,respectively.After loading Ag NPs,the spindle-like Ag/La2 O2 CO3 MNSs were used for phosphate removal and antibacterial activity.At the initial phosphate concentration of20 mg/L,the removal rate is 59.6%.The Ag/La2 O2 CO3 MNSs have significant antibacterial activity and their MIC values for S.aureus and E.coli are 31.3 and 15.6μg/mL,respectively.The results indicate that Ag/La2 O2 CO3 MNSs may have good application prospects in open water to inhibit bacterial growth.