scholarly journals Adsorption/reduction of N-dimethylnitrosamine from aqueous solution using nano zero-valent iron nanoparticles supported on ordered mesoporous silica

2017 ◽  
Vol 17 (4) ◽  
pp. 1097-1105 ◽  
Author(s):  
Xiaodong Xin ◽  
Shaohua Sun ◽  
Mingquan Wang ◽  
Qinghua Zhao ◽  
Yan Chen ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Iron Nanoparticles ◽  
Catalytic Reduction ◽  
High Surface ◽  
High Surface Area ◽  
Zero Valent Iron ◽  
Product Analysis ◽  
Solution Ph ◽  
Zero Valent Iron Nanoparticles ◽  
Mcm 41

N-Dimethylnitrosamine (NDMA) has aroused increasing concern among public health agencies. It is necessary to develop some effective methods to remove NDMA from drinking water. A reductive process has been investigated as an alternative treatment method for NDMA removal from water. In this manuscript, zero-valent iron nanoparticles (ZVINPs) were synthesized, and then supported on mesoporous silica materials with high surface area (MCM-41) to prepare a stable ZVINP/MCM-41 nanocomposite. X-ray diffraction measurements showed the stabilization of the ZVINPs upon their support on MCM-41, which enhanced their activity. The ZVINP/MCM-41 nanocomposite was used for the catalytic reduction of NDMA in the model solution, and the results showed the dependency of the removal process on the ZVINP/MCM-41 mass, time of removal, and solution pH. The mechanism of NDMA reduction by ZVINP/MCM-41 was studied, and the results showed the conversion of NDMA to unsymmetrical dimethylhydrazine, dimethylamine (DMA) and NH4+. The product analysis found that in the process of removal, adsorption and reduction existed at the same time.

The Synthesis of High-Surface Area Silicon Carbide by Conversion Method Using Carbosilane Polymer

2014 ◽  
Vol 353 ◽  
pp. 244-247
Author(s):  
Eun Jin Jung ◽  
Yoon Joo Lee ◽  
Woo Teck Kwon ◽  
Y. Kim ◽  
Dong Geun Shin ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Mesoporous Silica ◽  
Surface Area ◽  
High Surface ◽  
Hollow Spheres ◽  
High Surface Area ◽  
Bet Analysis ◽  
Fibrous Morphology ◽  
High Surface Area Materials ◽  
Mcm 41

Since mesoporous silica such as MCM-41 and SBA-15 was developed, the study of the properties of high-surface area materials was accelerated. Moreover, the mesoporous silica is used as a template to produce high-surface materials by nanocasting technology. The purpose of this paper is the synthesis of a high surface silicon carbide sphere by the nanocasting technology. In this study, KCC-1 silica sphere was used as a template, and polycarbosilane and poly (phenyl carbosilane) were selected for precursor of silicon carbide. Carbosilane polymer gives advantage of synthesis silicon carbide under low temperature, and hollow spheres were produced. In this study, the polycarbosilane was more effective for the synthesis of SiC hollow spheres by inversion of template structure showing a fibrous morphology on the sphere wall. And it was confirmed that the sphere was composed of nanosized SiC crystals, and has high surface area using TEM, XRD and BET analysis.

High Surface Area Mesoporous Silica for Hydrogen Sulfide Effective Removal

2020 ◽  
Vol 16 (2) ◽  
pp. 226-234
Author(s):  
Gomaa Abdelgawad Mohammed Ali ◽  
Ahmed Barhoum ◽  
Vinod Kumar Gupta ◽  
Amr Ahmed Nada ◽  
Heba Hassan El-Maghrabi ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Superior Performance ◽  
Economic Losses ◽  
Process Equipment ◽  
Maximum Adsorption Capacity ◽  
High Porosity ◽  
Mcm 41

Background: Removal of sulfur-containing compounds from the aqueous environment is necessary as these compounds pose potential risks to human health, hygienic management and bring great economic losses due to fouling of resin bed and corrosion of process equipment. Objective: This work aims to study the H2S removal efficiency using high surface area mesoporous silica (MCM–41). Methods: In this study, mesoporous silica (MCM–41) with a high surface area of 1270 m2/g and high porosity of 69% was prepared by sol-gel technique. Results: The obtained MCM–41 has exhibited a superior performance in adsorbing H2S from wastewater with a maximum adsorption capacity of 52.14 mg/g. The adsorption isotherm and kinetics of the current adsorption process are best represented by Freundlich isotherm and pseudo-secondorder models, respectively. Conclusion: Therefore, MCM–41 is an excellent adsorbent for wastewater treatment applications.

Facile Synthesis of Cu2O nanoparticle-loaded Carbon Nanotubes Composite Catalysts for Reduction of 4-Nitrophenol

2020 ◽  
Vol 16 (4) ◽  
pp. 617-624 ◽  
Author(s):  
Yao Feng ◽  
Ran Wang ◽  
Juanjuan Yin ◽  
Fangke Zhan ◽  
Kaiyue Chen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Mechanical Stability ◽  
Catalytic Reduction ◽  
High Surface ◽  
High Surface Area ◽  
Reduction Reaction ◽  
Cycle Performance ◽  
Simple Method ◽  
Composite Catalysts ◽  
Cu2o Nanoparticles

Background: 4-nitrophenol (4-NP) is one of the pollutants in sewage and harmful to human health and the environment. Cu is a non-noble metal with catalytic reduction effect on nitro compounds, and.has the advantages of simple preparation, abundant reserves, and low price. Carbon nanotubes (CNT) are widely used for substrate due to their excellent mechanical stability and high surface area. In this study, a simple method to prepare CNT-Cu2O by controlling different reaction time was reported. The prepared nanocomposites were used to catalyze 4-NP. Methods: CNTs and CuCl2 solution were put into a beaker, and then ascorbic acid and NaOH were added while continuously stirring. The reaction was carried out for a sufficiently long period of time at 60°C. The prepared samples were dried in a vacuum at 50°C for 48 h after washing with ethyl alcohol and deionized water. Results: Nanostructures of these composites were characterized by scanning electron microscope and transmission electron microscopy techniques, and the results at a magnification of 200 nanometers showed that Cu2O was distributed on the surface of the CNTs. In addition, X-ray diffraction was performed to further confirm the formation of Cu2O nanoparticles. The results of ultraviolet spectrophotometry showed that the catalytic effect of the compound on 4-NP was obvious. Conclusions: CNTs acted as a huge template for loading Cu2O nanoparticles, which could improve the stability and cycle performance of Cu2O. The formation of nanoparticles was greatly affected by temperature and the appropriate concentration, showing great reducibility for the 4-NP reduction reaction.

scholarly journals Zero-Valent Iron Nanoparticles for Soil and Groundwater Remediation

2020 ◽  
Vol 17 (16) ◽  
pp. 5817
Author(s):  
Alazne Galdames ◽  
Leire Ruiz-Rubio ◽  
Maider Orueta ◽  
Miguel Sánchez-Arzalluz ◽  
José Luis Vilas-Vilela
Keyword(s):  
Contaminated Soils ◽  
Groundwater Remediation ◽  
Iron Nanoparticles ◽  
Environmental Issues ◽  
High Specific Surface Area ◽  
Zero Valent Iron ◽  
Pilot Studies ◽  
High Effectiveness ◽  
Nanosized Materials ◽  
Zero Valent Iron Nanoparticles

Zero-valent iron has been reported as a successful remediation agent for environmental issues, being extensively used in soil and groundwater remediation. The use of zero-valent nanoparticles have been arisen as a highly effective method due to the high specific surface area of zero-valent nanoparticles. Then, the development of nanosized materials in general, and the improvement of the properties of the nano-iron in particular, has facilitated their application in remediation technologies. As the result, highly efficient and versatile nanomaterials have been obtained. Among the possible nanoparticle systems, the reactivity and availability of zero-valent iron nanoparticles (NZVI) have achieved very interesting and promising results make them particularly attractive for the remediation of subsurface contaminants. In fact, a large number of laboratory and pilot studies have reported the high effectiveness of these NZVI-based technologies for the remediation of groundwater and contaminated soils. Although the results are often based on a limited contaminant target, there is a large gap between the amount of contaminants tested with NZVI at the laboratory level and those remediated at the pilot and field level. In this review, the main zero-valent iron nanoparticles and their remediation capacity are summarized, in addition to the pilot and land scale studies reported until date for each kind of nanomaterials.

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