scholarly journals Simultaneous Adsorption and Degradation of Cr(VI) and Cd(II) Ions from Aqueous Solution by Silica-Coated Fe0Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yongchao Li ◽  
Hongpu Ma ◽  
Bozhi Ren ◽  
Tielong Li
Keyword(s):  
Aqueous Solution ◽  
Active Site ◽  
Removal Rate ◽  
Core Shell ◽  
Simultaneous Removal ◽  
Stöber Method ◽  
Removal Capacity ◽  
Batch Tests ◽  
One Step ◽  
Modified Stöber Method

Core-shell silica-coated Fe0nanoparticles (Fe@SiO2) were prepared in one-step synthesis by aqueous reduction combined with modified Stöber method. The as-prepared Fe@SiO2were then used for simultaneous removal of Cr(VI) and Cd(II) from aqueous solution. Batch tests indicated that Fe@SiO2exhibited high removal capacity toward Cr(VI) and Cd(II). Cr(VI) was removed by Fe@SiO2through reduction rather than adsorption, while Cd(II) removal was mainly through adsorption. The removal rate increased with increasing initial Fe NPs dose and decreased with increasing initial Cr(VI) and Cd(II) concentrations. Cd(II) adsorption was also strengthened by Cr(VI) reduction with the release of OH−. The removals of Cr(VI) and Cd(II) were weakened in the presence of cations or humic acid, as a result of aggregation and less active site of Fe@SiO2. Overall, the simply prepared Fe@SiO2were potential material for the heavy metals removed from water.

Core–Shell Fe@SiO2 Nanoparticles Synthesized via Modified Stober Method for High Activity in Cr(VI) Reduction

2018 ◽  
Vol 18 (10) ◽  
pp. 6867-6872 ◽  
Author(s):  
Van Thi Thanh Ho ◽  
Nguyen Vu Hoa Hong ◽  
At Van Nguyen ◽  
Long Giang Bach ◽  
Tuan Phan Dinh
Keyword(s):  
High Activity ◽  
Sio2 Nanoparticles ◽  
Core Shell ◽  
Stöber Method ◽  
Modified Stöber Method

Responsive P(NIPAM-co-AA) Particle-Functionalized Magnetic Microspheres

2014 ◽  
Vol 67 (1) ◽  
pp. 134 ◽  
Author(s):  
Yiheng Wang ◽  
Mengge Xia ◽  
Yongtao Wu ◽  
Meifang Zhu
Keyword(s):  
Magnetic Microspheres ◽  
Core Shell ◽  
The Novel ◽  
Shell Nanoparticles ◽  
Stöber Method ◽  
Preparation Conditions ◽  
Amidation Reaction ◽  
Modified Stöber Method ◽  
Core Shell Nanoparticles ◽  
Seed Emulsion Polymerization

Functionalized magnetic microspheres were prepared by anchoring cross-linked core–shell poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AA)) nanoparticles onto silica-coated magnetic microspheres (Fe3O4@SiO2). First, the smaller polystyrene/P(NIPAM-co-AA) core–shell nanoparticles were synthesized through seed emulsion polymerization and adhered to the surface of amino-modified Fe3O4@SiO2 micorspheres, which were made using the modified Stöber method through electrostatic interaction under appropriate preparation conditions. An amidation reaction between the carboxylic and amino groups on the respective surfaces was then catalyzed. Finally, the novel architecture magnetic microspheres with multiresponsive functionalities were obtained, and their polymerization conditions, environmental sensitivity, and magnetic properties were discussed and optimized. The superparamagnetism and temperature/pH dual responsivity and excellent dispersibility of the P(NIPAM-co-AA) functionalized magnetic microspheres provide them with high potential to be used in the fields of controlled drug delivery, bioseparation, and catalysis.

Preparation of structurally colored films assembled by using polystyrene@silica, air@silica and air@carbon@silica core–shell nanoparticles with enhanced color visibility

RSC Advances ◽  
2016 ◽  
Vol 6 (44) ◽  
pp. 37535-37543 ◽  
Author(s):  
Fen Wang ◽  
Xin Zhang ◽  
Jianfeng Zhu ◽  
Ying Lin
Keyword(s):  
Core Shell ◽  
Shell Nanoparticles ◽  
Stöber Method ◽  
Silica Core ◽  
Modified Stöber Method ◽  
Core Shell Nanoparticles

Polystyrene@silica (PS@SiO2) core–shell nanospheres were synthesized using a surfactant free method followed by a modified Stöber method in the research reported in this paper.

Synthesis and Photophysical Properties of Core–Shell Eu(DBM)3phen/TiO2 Nanohybrids

2008 ◽  
Vol 8 (3) ◽  
pp. 1464-1467 ◽  
Author(s):  
Weiping Qin ◽  
Dan Zhao ◽  
Jisen Zhang ◽  
Jishuang Zhang ◽  
Yan Wang ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Experimental Results ◽  
Core Shell ◽  
Complex Surfaces ◽  
Stöber Method ◽  
The Core ◽  
Ultraviolet Excitation ◽  
Modified Stöber Method ◽  
The Eu

The core–shell titania (TiO2) hybrid spheres embedded with tris(dibenzoylmethanato)phenanthroline [Eu-(DBM)3phen] complex clusters were fabricated by a modified Stöber method. Under ultraviolet excitation (355 nm), the hybrid spheres exhibit the characteristic luminescence of the Eu3+ ions. The experimental results indicate that the titanic shell has different influences on the two fluorescent centers of Eu3+ ions. The emission from the centers on the complex surfaces was greatly enhanced when incorporated into titania spheres.

Simultaneous Removal of Heavy-Metal Ions by MnO2 Loaded D301 Resin

2011 ◽  
Vol 255-260 ◽  
pp. 2791-2796 ◽  
Author(s):  
Hong Mei Ma ◽  
Zhi Liang Zhu ◽  
Yong Qian Cheng
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Alkaline Earth ◽  
Removal Rate ◽  
Alkaline Earth Metals ◽  
Simultaneous Removal ◽  
High Concentration ◽  
Solution Ph

MnO2-loaded D301 weak basic anion exchange resin was used as adsorbent to simultaneously remove Co2+, Ni2+, Cd2+, Zn2+ andCu2+ from aqueous solution contained high concentration of alkali and alkaline-earth metals ions. The effects of solution pH and coexistent ions on the adsorption were investigated. The results indicated that Co2+, Ni2+, Cd2+, Zn2+ andCu2+ can be simultaneously removed in the wide pH range of 3 to 8. The coexistence of PO43− decreased the heavy metal ions removal rate, but for other high concentrations coexistence cations and anions such as Na+, K+, Cl−, NO3−, SO42− and HCO3−, there is no significant impact on removal rate of heavy metals. The adsorption isotherm can be well described by Langmuir isotherm. The adsorption processes followed the pseudo first-order kinetics model. High adsorption capacity makes it a good promising candidate material for simultaneous removal of Co2+, Ni2+, Cd2+, Zn2+ andCu2+ from aqueous solution with the co-existence of high concentration of alkali and alkaline-earth metals ions.

Nonsurfactant Surface Modifications of Monodispersed Si-Cu Core-Shell Nanocomposite

2014 ◽  
Vol 895 ◽  
pp. 571-574
Author(s):  
Musdalilah Ahmad Salim ◽  
Halina Misran ◽  
S.Z. Othman ◽  
N.N.H. Shah ◽  
N.A.A. Razak ◽  
...  
Keyword(s):  
Sol Gel ◽  
Core Shell ◽  
Silica Spheres ◽  
X Ray Diffraction ◽  
Stöber Method ◽  
X Ray ◽  
Silica Surfaces ◽  
Nonsurfactant Template ◽  
Diffraction Patterns ◽  
Modified Stöber Method

Monodispersed silica spheres with particles size of ca. 450 nm were successfully synthesized using modified Stöber method. The synthesized monodispersed silica spheres were successfully coated with copper through modified sol-gel method employing nonsurfactant template and catalyst. A renewable nonsurfactant template, decyl-alcohol (C10) and catalyst were used to modify the silica surfaces prior to coating with copper. In order to study the effect of catalyst on copper deposition onto silica surfaces, ammonia was used as catalyst in various amounts. The X-ray diffraction patterns of Si-Cu core-shell exhibited a broad peak corresponding to amorphous silica networks and exhibited monoclinic CuO phase. It was found that samples modified in the presence of 1 ml catalyst exhibited relatively homogeneous deposition. The surface area of uncoated core (SiO2) was at ca. 7.04 m2/g and coated samples 1 ml catalyst was at ca. 8.21m2/g.

scholarly journals Bioremediation of Aquaculture Wastewater with Algal-Bacterial Biofilm Combined with the Production of Selenium Rich Biofertilizer

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2071 ◽  
Author(s):  
Wei Han ◽  
Yufeng Mao ◽  
Yunpeng Wei ◽  
Peng Shang ◽  
Xu Zhou
Keyword(s):  
Removal Rate ◽  
Growth Period ◽  
Dry Weight ◽  
Bacterial Biofilm ◽  
Biofilm Growth ◽  
Weight Density ◽  
Removal Capacity ◽  
Batch Tests ◽  
Effective Removal ◽  
Aquaculture Wastewater

The discharge of aquaculture wastewater and the excessive selenium in aquaculture effluent caused by selenium addition to aquatic feed are posing a serious risk for the marine environment. In this study, batch tests were carried out to investigate the feasibility of utilizing algal–bacterial biofilm for the treatment of selenium-rich aquaculture wastewater. The effects of four different types of commercial biofilm carriers on the attached growth of biofilms and the contaminant removal capacity were examined. The braided cotton biofilm carrier had the best performance on biofilm growth, while in an exponential growth period the dry weight density of the biofilm was above 2.0 g L−1. By utilizing the braided cotton carrier with a hydraulic retention time (HRT) of 6 days, the removal rate of N and P from the raw aquaculture wastewater was 88.5 ± 6.2% and 99.8 ± 0.2%, respectively. After that, the effects of different initial wastewater load ratios (IWLR) and HRT on the effluent quality of the treatment process were studied. The decrease in IWLR and the extension of HRT could improve the treatment performance. The effluent N, P and Se concentrations in the group with 50% IWLR and 6-day HRT were 0.75 ± 0.10 mg L−1, 0.015 ± 0.02 mg L−1, 35.2 ± 3.2 μg L−1, respectively, indicating an effective removal of the main contaminants. The algal–bacterial biofilm harvested from the batch test was rich in N, P and Se, where the Se content was 21.8 ± 3.4 mg kg−1, which has the potential to be used as an Se-rich biofertilizer.

Facile synthesis of core–shell structured ZrO 2 @SiO 2 via a modified Stöber method

2016 ◽  
Vol 42 (6) ◽  
pp. 7583-7592 ◽  
Author(s):  
Ailing Bai ◽  
Hao Song ◽  
Gaoyin He ◽  
Qingsong Li ◽  
Chong Yang ◽  
...  
Keyword(s):  
Core Shell ◽  
Facile Synthesis ◽  
Stöber Method ◽  
Modified Stöber Method
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