Research of the Surface Changes in the Modification Process of Activated Carbon

2014 ◽  
Vol 526 ◽  
pp. 40-45 ◽  
Author(s):  
Xiao Pin Wang ◽  
Yi Hui Li ◽  
Cou Hua Zhu
Keyword(s):  
Activated Carbon ◽  
Surface Morphology ◽  
Carbon Surface ◽  
Manganese Ions ◽  
Microcrystalline Structure ◽  
Modified Model ◽  
Modification Process ◽  
Graphite Crystallite ◽  
Irregular Loading ◽  
Surface Changes

This paper studied the changes in the surface morphology and microcrystalline structure of GAC modified using the original activated carbon, HNO3, FeCl2·4H20, KMnO4. The micro pore structure on the surface is damaged after being treated by HNO3, and the transition pores increase; after being treated by FeCl2·4H20 and KMnO4,the carbon surface is irregular, and there is a protuberance, which is due to the irregular loading of manganese ions on the activated carbon surface. Then the roughness of the activated carbon increases and the size of graphite crystallite of GAC is also greatly reduced, showing obvious trend of fine grains. Meanwhile, the studies of the effect of removing the trichlorophenol from water after modification indicate that the results basically match. On this basis, the modified model is put forward.

Adsorption of Carbon Dioxide onto Activated Carbon and Nitrogen-Enriched Activated Carbon: Surface Changes, Equilibrium, and Modeling of Fixed-Bed Adsorption

2009 ◽  
Vol 45 (1) ◽  
pp. 73-84 ◽  
Author(s):  
Tirzhá L. P. Dantas ◽  
Suélen M. Amorim ◽  
Francisco Murilo T. Luna ◽  
Ivanildo J. Silva ◽  
Diana C. S. de Azevedo ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Activated Carbon ◽  
Fixed Bed ◽  
Carbon Surface ◽  
Carbon And Nitrogen ◽  
Fixed Bed Adsorption ◽  
Surface Changes

scholarly journals The influence of active carbon contaminants on the ozonation mechanism interpretation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lilla Fijołek ◽  
Joanna Świetlik ◽  
Marcin Frankowski
Keyword(s):  
Activated Carbon ◽  
Active Carbon ◽  
Alkali Metals ◽  
Activated Carbons ◽  
Carbon Surface ◽  
Bulk Solution ◽  
Ozone Decomposition ◽  
Reaction Products ◽  
Treatment Technology ◽  
Carbon Impurities

AbstractIn water treatment technology, activated carbons are used primarily as sorbents to remove organic impurities, mainly natural organic matter, but also as catalysts in the ozonation process. Commercially available activated carbons are usually contaminated with mineral substances, classified into two main groups: alkali metals (Ca, Na, K, Li, Mg) and multivalent metals (Al, Fe, Ti, Si). The presence of impurities on the carbon surface significantly affects the pHpzc values determined for raw and ozonated carbon as well as their acidity and alkalinity. The scale of the observed changes strongly depends on the pH of the ozonated system, which is related to the diffusion of impurities from the carbon to the solution. In an acidic environment (pH 2.5 in this work), the ozone molecule is relatively stable, yet active carbon causes its decomposition. This is the first report that indirectly indicates that contaminants on the surface of activated carbon (multivalent elements) contribute to the breakdown of ozone towards radicals, while the process of ozone decomposition by purified carbons does not follow the radical path in bulk solution. Carbon impurities also change the distribution of the reaction products formed by organic pollutants ozonation, which additionally confirms the radical process. The study showed that the use of unpurified activated carbon in the ozonation of succinic acid (SA) leads to the formation of a relatively large amount of oxalic acid (OA), which is a product of radical SA degradation. On the other hand, in solutions with purified carbon, the amount of OA generated is negligible.

Study on Thermal Regeneration for Caffeine-Saturated Activated Carbon

2013 ◽  
Vol 781-784 ◽  
pp. 1941-1944 ◽  
Author(s):  
Zhao You Zhu ◽  
Li Li Wang ◽  
Wan Ling Wang ◽  
Ying Long Wang
Keyword(s):  
Activated Carbon ◽  
Carbon Layer ◽  
Carbon Surface ◽  
Optimum Conditions ◽  
Gas Velocity ◽  
Thermal Regeneration ◽  
Regeneration Time ◽  
Before And After ◽  
Carbon Regeneration ◽  
Carrier Gas Velocity

Waste activated carbon (AC) containing caffeine was produced during the process of the production for caffeine. The process of treatment caffeine-saturated AC using thermal regeneration was explored and factors on the regeneration of activated carbon were investigated. The optimum conditions obtained were: temperature is 650 °C, the regeneration time is 180 min, the carrier gas velocity is 0.002 m/s, carbon layer thickness is 0.1 m. Under these conditions, activated carbon regeneration efficiency reached 90.3%. In addition, the pore structure of activated carbon before and after regeneration was characterized and the activated carbon surface area and pore size distribution under optimum conditions were determined by the adsorption isotherms.

scholarly journals A Study of the Removal of Minor Amounts of H2S from Natural Gas by Activated Carbon

2002 ◽  
Vol 20 (10) ◽  
pp. 969-976 ◽  
Author(s):  
Li Zhou ◽  
Ping Chen ◽  
Ming Li ◽  
Yaping Zhou
Keyword(s):  
Activated Carbon ◽  
Natural Gas ◽  
Considerable Effect ◽  
Carbon Surface

Studies have been made of the removal of minor amounts of H2S from natural gas by activated carbon. The surface alkalinity of the carbon had a considerable effect on the H2S capacity, although this was not permanent. Thus, when the carbon surface became neutral, the H2S content remained constant after the initial cycles of the purification/regeneration operation. The presence of water in natural gas was found to be critical for the use of activated carbon as a means of sweetening natural gas. However, although it enhanced the H2S capacity of the carbon, it made regeneration of the latter very difficult.

scholarly journals The Effect of Sulphur Dioxide Exposure under Controlled Environmental Conditions on the Challenge Performance of Copper and Chromate Impregnated Active Carbon against Hydrogen Cyanide

1997 ◽  
Vol 15 (7) ◽  
pp. 531-540 ◽  
Author(s):  
P.J.C. Anstice ◽  
J.F. Alder
Keyword(s):  
Activated Carbon ◽  
Numerical Analysis ◽  
Flow Rate ◽  
Active Carbon ◽  
Environmental Conditions ◽  
Sulphur Dioxide ◽  
Hydrogen Cyanide ◽  
Carbon Surface ◽  
Adsorption Model ◽  
Active Centres

An ASC/T (Cu2+, Cr6+, Ag and triethylenediamine impregnated) Whetlerite activated carbon sample was exposed to a flow rate of 1 l/min, 0.746 mg/l SO2 in 80% RH air at 22°C for up to 510 min. Samples were subsequently challenged with 2 mg/l HCN in an identical diluent gas stream. Increasing SO2 exposure resulted in accelerated HCN and (CN)2 bed penetration. The basic shapes of the breakthrough profiles were however essentially unchanged. This observation is in accordance with numerical analysis of these results using Hinshelwood's adsorption model, which suggested that the adsorption rate constant was not significantly affected by SO2 but rather the pollutant exposure resulted in the number of active centres on the carbon surface being reduced and the effective bed depth of the sample being shortened. This loss in active centres was thought most likely to result from the reduction of Cr6+ to Cr3+.

scholarly journals Tin Complexes Containing an Atenolol Moiety as Photostabilizers for Poly(Vinyl Chloride)

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2923
Author(s):  
Baneen Salam ◽  
Gamal A. El-Hiti ◽  
Muna Bufaroosha ◽  
Dina S. Ahmed ◽  
Ahmed Ahmed ◽  
...  
Keyword(s):  
Weight Loss ◽  
Infrared Spectroscopy ◽  
Surface Morphology ◽  
Vinyl Chloride ◽  
Poly Vinyl Chloride ◽  
Phenyl Rings ◽  
Tin Complexes ◽  
High Yields ◽  
Loss Determination ◽  
Surface Changes

The lifetime of poly(vinyl chloride) (PVC) can be increased through the addition of additives to provide protection against irradiation. Therefore, several new tin complexes containing atenolol moieties were synthesized and their photostabilizing effect on PVC was investigated. Reacting atenolol with a number of tin reagents in boiling methanol provided high yields of tin complexes. PVC was then mixed with the tin complexes at a low concentration, producing polymeric thins films. The films were irradiated with ultraviolet light and the resulting damage was assessed using different analytical and surface morphology techniques. Infrared spectroscopy and weight loss determination indicated that the films incorporating tin complexes incurred less damage and less surface changes compared to the blank film. In particular, the triphenyltin complex was very effective in enhancing the photostability of PVC, and this is due to its high aromaticity (three phenyl rings) compared to other complexes. Such an additive acts as a hydrogen chloride scavenger, radical absorber, and hydroperoxide decomposer.

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