Enhancing the stability of immobilized catalase on activated carbon with gelatin encapsulation

2013 ◽  
Vol 130 (3) ◽  
pp. 1498-1502 ◽  
Author(s):  
Yulin Wang ◽  
Yuepeng Guan ◽  
Yin Yang ◽  
Peng Yu ◽  
Yaqin Huang
Keyword(s):  
Activated Carbon ◽  
Immobilized Catalase ◽  
The Stability

scholarly journals Performance of Iron-Functionalized Activated Carbon Catalysts (Fe/AC-f) on CWPO Wastewater Treatment

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 337
Author(s):  
Sara Mesa Medina ◽  
Ana Rey ◽  
Carlos Durán-Valle ◽  
Ana Bahamonde ◽  
Marisol Faraldos
Keyword(s):  
Wastewater Treatment ◽  
Activated Carbon ◽  
Landfill Leachate ◽  
Surface Composition ◽  
Treatment Plant ◽  
Reaction Medium ◽  
Pollutant Removal ◽  
Operating Conditions ◽  
Water Matrix ◽  
The Stability

Two commercial activated carbon were functionalized with nitric acid, sulfuric acid, and ethylenediamine to induce the modification of their surface functional groups and facilitate the stability of corresponding AC-supported iron catalysts (Fe/AC-f). Synthetized Fe/AC-f catalysts were characterized to determine bulk and surface composition (elemental analysis, emission spectroscopy, XPS), textural (N2 isotherms), and structural characteristics (XRD). All the Fe/AC-f catalysts were evaluated in the degradation of phenol in ultrapure water matrix by catalytic wet peroxide oxidation (CWPO). Complete pollutant removal at short reaction times (30–60 min) and high TOC reduction (XTOC = 80 % at ≤ 120 min) were always achieved at the conditions tested (500 mg·L−1 catalyst loading, 100 mg·L−1 phenol concentration, stoichiometric H2O2 dose, pH 3, 50 °C and 200 rpm), improving the results found with bare activated carbon supports. The lability of the interactions of iron with functionalized carbon support jeopardizes the stability of some catalysts. This fact could be associated to modifications of the induced surface chemistry after functionalization as a consequence of the iron immobilization procedure. The reusability was demonstrated by four consecutive CWPO cycles where the activity decreased from 1st to 3rd, to become recovered in the 4th run. Fe/AC-f catalysts were applied to treat two real water matrices: the effluent of a wastewater treatment plant with a membrane biological reactor (WWTP-MBR) and a landfill leachate, opening the opportunity to extend the use of these Fe/AC-f catalysts for complex wastewater matrices remediation. The degradation of phenol spiked WWTP-MBR effluent by CWPO using Fe/AC-f catalysts revealed pH of the reaction medium as a critical parameter to obtain complete elimination of the pollutant, only reached at pH 3. On the contrary, significant TOC removal, naturally found in complex landfill leachate, was obtained at natural pH 9 and half stoichiometric H2O2 dose. This highlights the importance of the water matrix in the optimization of the CWPO operating conditions.

Nanocomposite Detection of Elemental Impurities and Process Correlation Analysis of Ceftriaxone Sodium for Injection

2020 ◽  
Vol 12 (12) ◽  
pp. 1458-1463
Author(s):  
Li Zhu ◽  
Xiaomeng Chong ◽  
Yu Zhao ◽  
Mingzhe Xu ◽  
Lihui Yin
Keyword(s):  
Activated Carbon ◽  
Generic Drug ◽  
Inductively Coupled Plasma ◽  
Plasma Spectroscopy ◽  
Inductively Coupled ◽  
Elemental Impurities ◽  
Ceftriaxone Sodium ◽  
The Stability ◽  
Impurity Elements ◽  
First Time

An inductively coupled plasma spectroscopy method was established to detect 29 elemental impurities in ceftriaxone sodium for injection by nanocomposite, and also used to detect the elemental impurities in the generic, domestic original and foreign original ceftriaxone sodium for injection. This paper for the first time analysed the possible sources of elemental impurities and their potential impacts on the drug quality based on the process. The results showed that zinc and potassium were detected in both the generic drug and the domestic original ceftriaxone sodium for injection, and zinc was not detected but potassium was detected in the foreign original drug; the content of zinc in the generic drug was significantly higher than that in the domestic original drug, and the content of potassium in generic drug and domestic original drug was higher than that in the foreign original drug, according to the process, the elemental impurities may come from the activated carbon or nanocarriers used in the process, and further stability analysis of the samples showed that the stability of the generic drug was slightly lower than that of the original drug, so it was speculated that impurity elements might also be one of the reasons for its instability.

scholarly journals Catalytic Performance of Nitrogen-Doped Activated Carbon Supported Pd Catalyst for Hydrodechlorination of 2,4-Dichlorophenol or Chloropentafluoroethane

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 674 ◽  
Author(s):  
Haodong Tang ◽  
Bin Xu ◽  
Meng Xiang ◽  
Xinxin Chen ◽  
Yao Wang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Liquid Phase ◽  
Gas Phase ◽  
Nitrogen Doping ◽  
Catalyst Surface ◽  
Catalytic Performance ◽  
Atomic Ratio ◽  
Pd Catalyst ◽  
Nitrogen Doped ◽  
The Stability

Nitrogen-doped activated carbon (N-AC) obtained through the thermal treatment of a mixture of HNO3-pretreated activated carbon (AC) and urea under N2 atmosphere at 600 °C was used as the carrier of Pd catalyst for both liquid-phase hydrodechlorination of 2,4-dichlorophenol (2,4-DCP) and gas-phase hydrodechlorination of chloropentafluoroethane (R-115). The effects of nitrogen doping on the dispersion and stability of Pd, atomic ratio of Pd/Pd2+ on the surface of the catalyzer, the catalyst’s hydrodechlorination activity, as well as the stability of N species in two different reaction systems were investigated. Our results suggest that, despite no improvement in the dispersion of Pd, nitrogen doping may significantly raise the atomic ratio of Pd/Pd2+ on the catalyst surface, with a value of 1.2 on Pd/AC but 2.2 on Pd/N-AC. Three types of N species, namely graphitic, pyridinic, and pyrrolic nitrogen, were observed on the surface of Pd/N-AC, and graphitic nitrogen was stable in both liquid-phase hydrodechlorination of 2,4-DCP and gas-phase hydrodechlorination of R-115, with pyridinic and pyrrolic nitrogen being unstable during gas-phase hydrodechlorination of R-115. As a result, the average size of Pd nanocrystals on Pd/N-AC was almost kept unchanged after liquid-phase hydrodechlorination of 2,4-DCP, whereas crystal growth of Pd was clearly observed on Pd/N-AC after gas-phase hydrodechlorination of R-115. The activity test revealed that Pd/N-AC exhibited a much better performance than Pd/AC in liquid-phase hydrodechlorination of 2,4-DCP, probably due to the enhanced stability of Pd exposed to the environment resulting from nitrogen doping as suggested by the higher atomic ratio of Pd/Pd2+ on the catalyst surface. In the gas-phase hydrodechlorination of R-115, however, a more rapid deactivation phenomenon occurred on Pd/N-AC than on Pd/AC despite a higher activity initially observed on Pd/N-AC, hinting that the stability of pyridinic and pyrrolic nitrogen plays an important role in the determination of catalytic performance of Pd/N-AC.

Effect of oxidation treatment on the adsorption and the stability of mercury on activated carbon

2006 ◽  
Vol 18 (6) ◽  
pp. 1161-1166 ◽  
Author(s):  
Chang-xing HU ◽  
Jin-song ZHOU ◽  
Zhong-yang LUO ◽  
Sheng HE ◽  
Guang-kai WANG ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Oxidation Treatment ◽  
The Stability

Synergistically boosting electrochemical performance of polypyrrole coated-activated carbon derived from carbon dots for high-performance supercapacitor

2021 ◽  
Author(s):  
Lanxin Wang ◽  
QingXin Zeng ◽  
Qiuhong Chen ◽  
Chang Ming Li ◽  
Jiucun Chen
Keyword(s):  
Activated Carbon ◽  
Electrochemical Performance ◽  
Hybrid Materials ◽  
Carbon Dots ◽  
High Performance ◽  
Carbon Materials ◽  
The Stability

The hybrid materials prepared by the controlled fumigation polymerization of pyrrole on the surface of activated carbon derived from carbon dots combined the stability of carbon materials, the wettability of...

scholarly journals Ruthenium on Carbonaceous Materials for the Selective Hydrogenation of HMF

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2007 ◽  
Author(s):  
Stefano Cattaneo ◽  
Hadi Naslhajian ◽  
Ferenc Somodi ◽  
Claudio Evangelisti ◽  
Alberto Villa ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Carbon Nanofibers ◽  
Reaction Temperature ◽  
Selective Hydrogenation ◽  
Liquid Fuel ◽  
Hydrogen Pressure ◽  
Carbonaceous Materials ◽  
Fuel Additives ◽  
Ru Catalysts ◽  
The Stability

We report the use of Ru catalysts supported in the activated carbon (AC) and carbon nanofibers (CNFs) for the selective production of liquid fuel dimethylfuran (DMF) and fuel additives alkoxymethyl furfurals (AMF). Parameters such as the reaction temperature and hydrogen pressure were firstly investigated in order to optimise the synthesis of the desired products. Simply by using a different support, the selectivity of the reaction drastically changed. DMF was produced with AC as support, while a high amount of AMF was produced when CNFs were employed. Moreover, the reusability of the catalysts was tested and deactivation phenomena were identified and properly addressed. Further studies need to be performed in order to optimise the stability of the catalysts.

Dual-Frequency Ultrasonic Desorption of Pb2+ from Coconut Shell Activated Carbon

2013 ◽  
Vol 777 ◽  
pp. 38-42
Author(s):  
Jian Zhou ◽  
San Fan Wang
Keyword(s):  
Activated Carbon ◽  
Metal Ion ◽  
Coconut Shell ◽  
Single Frequency ◽  
Dual Frequency ◽  
Cavitation Effect ◽  
Desorption Efficiency ◽  
The Stability ◽  
Coconut Shell Activated Carbon ◽  
Frequency Ultrasound

Desorption experiments of coconut shell activated carbon (CSAC) saturated with Pb2+had been conducted in presence of dual-frequency and single-frequency (30 kHz,500 kHz,1200 kHz) ultrasound. The desorption efficiency was better at dual-frequency ultrasound than at single-frequency ultrasound. The best of desorption efficiency of Pb2+was 65.5% at 500×500 kHz. The desorption efficiency of Pb2+increased by increasing temperature, but when the temperature was more than 50°C, the desorption efficiency decreased initially. The stability of CSAC was not affected with cavitation effect produced by ultrasound of frequency of 500×500 kHz. The carbon loss was less. The rate of loss was only 0.6%. In conclusion, ultrasound was used as alternative method to regenerate activated carbon adsorbing with heavy metal ion.

Adsorption of Carboxymethylated Polyethyleneimine (CM-PEI) on a Microporous Activated Carbon

2007 ◽  
Vol 119 ◽  
pp. 103-106 ◽  
Author(s):  
Jei Won Yeon ◽  
Y. Jung ◽  
Won Ho Kim
Keyword(s):  
Activated Carbon ◽  
Adsorption Mechanism ◽  
Freundlich Isotherm ◽  
Carbon Surface ◽  
Chelating Polymer ◽  
Modification Technique ◽  
Adsorption Amount ◽  
The Stability ◽  
Ph Range ◽  
Adsorption Phenomena

We applied a polymer-based surface modification technique to the surface treatment of a microporous activated carbon. We used a new chelating polymer, carboxymethylated polyethyleneimine (CM-PEI), as a functional polymer to modify the carbon surface. In this study, we examined the adsorption phenomena of the CM-PEI on an activated carbon with a nanopore less than 2 nm in diameter and evaluated the adsorption mechanism using three kinds of models; Langmuir, Freundlich, and Redlich-Peterson isotherm. It was found that the adsorption of CM-PEI on the F400 follows the Freundlich isotherm model. Furthermore, desorption experiments of the CM-PEI were carried out to examine the stability of the CM-PEI adsorption on the F400 and to estimate the applicability of the CM-PEI-coated F400 to the adsorbents. It was observed that most of the CM-PEI remains on the F400 for 7 days in the pH range of 3 to 7. Especially, the adsorption amount of CM-PEI on the F400 did not change after 3 days at the pH range of 5 to 7, indicating that the CM-PEI strongly adheres to the F400.

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