CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Xueping Chen,Jinxin Liu,Yue Ma,Pan Wang,Xue Bai,Jianming Pan
Effective removal of Pb(II) is a pressing global issue for both drinking water and wastewater purification. In this work, the large-scale and low-cost synthesis of two functional silica sorbents by vapor condensation induced water-in-oil (W/O) nanoemulsions (NSEs) is proposed, and the obtained high quality sorbents are applied for rapid removal of Pb(II). Tetraethoxysilane (TEOS) is diffused into the droplet of NSEs reactor, and then naked silica spheres are generated by hydrolysis and condensation at room temperature. The effects of the reaction conditions and confined space, including the stability, pumping time of water-soluble gas, and condensing time etc. on the size, morphology, and yield of main product are investigated, and the possible formation mechanism is demonstrated. Furthermore, functional silica sorbents with defined surface chemistry (i.e. Si-NH 2 and Si-SH) are also synthesized via as-prepared NSEs systems. Finally, attributed to the inherent amino and mercapto terminal groups, Si-NH 2 and Si-SH illuminate the maximum sorption capacity of 245.7 mg g −1 and 72.16 mg g −1 for Pb(II), respectively. Surface charge does not play a significant role in Pb(II) capture by Si-NH 2 , while chemisorption and electrostatic interaction both contribute to uptake performance of Si-SH. NSEs formed by condensation of water vapor do not need violent stirring and strict component proportion, which is an alternative and potential strategy to synthesize functional sorbents.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
ADSORPTION-JOURNAL OF THE INTERNATIONAL ADSORPTION SOCIETY
·
2016
·Vol. 22
·期 7
·871-878
·
IF 1.87
Ge Li,Huang Hao,Qin Yanshu,Xia Fan,Yang Kedi
Ionic liquids (ILs)-bonded silica adsorbents were prepared by chemical modification of the silica surface using N -alkylimidazolium-based ILs with Cl − , BF 4
− , PF 6
− or NO 3
− anion, and applied to selective separation of the model mixture of luteolin and aloe-emodin. Among the investigated ILs-bonded silica materials, the silica grafted with N -octyllimidazolium hexafluorophosphate ([C 8 mim]PF 6 @SiO 2 ) exhibited higher adsorption capacity and selectivity of luteolin from the model mixed solution of luteolin and aloe-emodin. The isotherm data of luteolin on [C 8 mim]PF 6 @SiO 2 correlated better to the Freundlich model than the Langmuir model, and the calculated thermodynamic parameters indicated that the adsorption of luteolin was spontaneous and exothermic. The dynamic adsorption and elution experiments demonstrated that the high adsorption capacity and good desorption efficiency of luteolin on fixed bed packed with the [C 8 mim]PF 6 @SiO 2 . Moreover, the results from batch adsorption and dynamic adsorption showed well selective separation towards the model mixture of luteolin and aloe-emodin.
研究领域:
化学工程
·
分离科学
·
药物化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Xinqian Li,Bo Li,Shuqi Li,Yaping Dong,Dandan Gao,Zhengrong Niu,Wu Li,Haitao Feng
Removing impurities from hexavalent chromium system without secondary pollution is the key to the successful development of green chromate production technology. Here, hydrated chromium oxide CrO x (OH) 3-2x with lamellar cluster microsphere structure was prepared by in-situ hydrothermal method and used to simultaneously adsorb Si (IV) and V (V) in high concentration Cr (VI) solution. In the in-situ hydrothermal process of pH 7, 160 ℃ for 8 h, the Si (IV) and V (V) removal rates of the actual chromate production Na 2 Cr 2 O 7 -Na 2 SiO 3 -NaVO 3 -H 2 O solution can reach 92.27 % and 94.81 %, respectively, which is higher than the ex-situ removal efficiency of Si (IV) (62.88 %) and V (V) (63.16 %) under the same conditions. Further characterization of STEM-elemental mapping, XPS and FT-IR results indicate that during in-situ adsorption, Si (IV) and V (V) are mainly adsorbed on the surface of CrO x (OH) 3-2X adsorbent by interacting with surface hydroxyl groups. More importantly, the simultaneous formation and adsorption of the adsorbent are more conducive to the full utilization of active adsorption sites on the adsorbent surface. After that, CrO x (OH) 3-2x was converted into nano Cr 2 O 3 with a purity of 97.87 % by simple desorption and calcination processes. In addition, the results of UV–vis DRS and SEM show that the residual Si and V elements in Cr 2 O 3 unexpectedly increase the size of the particles to about 300 nm, which redshifts the absorption band of the blue region by 3.3 nm. This results in more red absorption and makes Cr 2 O 3 more yellowish-green and exhibits excellent pigment properties. Thus, the in-situ synthesis, synergistic adsorption and green conversion of trivalent chromium adsorbent provide a promising and sustainable technology for the purification of high concentration Cr (VI) solution that avoids the discharge of Cr (VI) containing slag.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
AUSTRALIAN JOURNAL OF CHEMISTRY
·
2015
·Vol. 68
·期 7
·1051-1064
·
IF 1.558
Yanmin Gao,Zhaoyong Hu,Yan Liu,Zhanchao Liu,Rui Chen,Xiangguo Meng,Mingjia Meng,Chao Zhou
Highly selective lead ion imprinted mesoporous silica adsorbents (PbII-IMS) were prepared through a co-condensation pathway with 3-(γ-aminoethylamino)propyltrimethoxysilane (AAPTS) (PbII-IMS-NN) and 3-aminepropyltriethoxysilyl (APTES) (PbII-IMS-N) as monomers. The prepared adsorbents were characterised by FT-IR spectroscopy, X-ray photoelectron spectroscopy, power X-ray diffraction, transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, and nitrogen adsorption–desorption techniques. The results showed that the synthesised adsorbents presented a highly ordered mesoporous structure. In comparison with PbII-IMS-N, PbII-IMS-NN demonstrated a higher adsorption capacity in a series of static and dynamic adsorption experiments, and was further applied to a continuous fixed-bed column study under different conditions. It was found that the breakthrough time of the fixed-bed increased with an increase in bed depth, but decreased with increased flow rate and initial PbII concentration, and the dynamic adsorption data was more consistent with the Thomas model than the Adams–Bohart model. Furthermore, the PbII-IMS-NN showed a greater recognition and binding affinity towards the target lead ions than PbII-IMS-N.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）